The October 2004 Mw=7.1 Nicaragua earthquake: Rupture process, aftershock locations, and the confluence of SEIZE and SubFac goals

A
A'
E
E
-88˚ -87˚ -86˚ -85˚ -84˚
9˚
10˚
11˚
12˚
13˚
10
10
10
10
5
5
5
5
5
5
5
5
5
1992 tsunami earthquake
epicenter
1992 event slip distribution
[Ihmlé,1996]
Major subevents of
moment release
Rupture area
Epicenter
1992 tsunami earthquake October 2004 event
Broadband Seismographs:
Tucan SEIZE Permanent
Volcanos
Slab isobaths, 50 km interval
In This Issue:
Science Articles
Nicaragua Earthquake......... 1-2
Subduction Factory .............. 3-5
S2S Meetings Update ........... 6-7
From the Chair .........................8-9
CSDMS Infrastructure ..............10
EPO Spotlight........................11-12
MARGINS at AGU .....................14
AGU Sessions ................... 14-16
MARGINS Lecture/Reception 17
Contact Information .................23
Published bi-annually by the
MARGINS Office
Washington University in St. Louis
1 Brookings Drive, CB 1169
St. Louis, MO 63130 USA
NewsletterNo.15,Fall2005
The October 2004 Mw
=7.1 Nicaragua
earthquake: Rupture process, aftershock
locations, and the confluence of
SEIZE and SubFac goals
Susan Bilek (New Mexico Tech); Geoffrey Abers (Boston University);
Gustavo Reyes (Boston University); Karen M. Fischer (Brown University);
Wilfried Strauch (Instituto Nicaragüense de Estudios Territoriales-INETER);
Victor Gonzalez Salas (OVSICORI)
The subduction zone off the Nicaragua
coastline has been the site of several large
earthquakes in the past decades, includ-
ing the 1992 tsunami earthquake that was
anomalous in the size of the tsunami rela-
tive to moment release [Kanamori and
Kikuchi, 1993]. As a focus site for both
the MARGINS-SEIZE and SubFac ini-
tiatives, it is an area of keen interest for
scientists interested in earthquake rupture
and volcanic processes.
The TUCAN group (Boston Univer-
sity, Brown University, INETER, and
OVSICORI) has been funded through
MARGINS to investigate the upper
mantle and subducting plate in Nicara-
gua and Costa Rica, using an 18 month
deployment of 48 broadband seismom-
eters to sample the arc structure [Abers
et al., 2004]. This experiment coinciden-
tally recorded a large (Mw
=7.1) earth-
quake that occurred along the plate
interface in a region close to the 1992 tsu-
nami earthquake, and was the largest that
Figure 1. Map of recent seismic activity and experiments in the Nicaragua region. The 2004
Mw
7.1 earthquake (star showing epicenter) occurred in a region close to the TUCAN
seismometers. The rupture area of the mainshock is shown by the black ellipse and aftershocks
recorded by the TUCAN network are shown by white circles. Slip from the mainshock occurs
downdip of the slip from the 1992 tsunami earthquake (blue contours), and aftershocks cover
much of the shallow dipping seismogenic zone.

MARGINS Newsletter No. 15, Fall 2005 Science Article
that year (Figure 1). Because of the for-
tuitous placement of so many broadband
seismographs, this event may be one of
the best-recorded events anywhere on an
interplate thrust fault of a subduction
zone. The New Mexico Tech group
(Bilek) has collaborated with TUCAN
PI’s on a small project to combine analy-
sis of the rupture process of the October
2004 earthquake with the aftershocks re-
corded by the TUCAN experiment.
Within 48 hours of the event, INETER
(the Nicaraguan monitoring agency and
TUCAN collaborators) were able to post
initial locations for over 100 aftershocks
on their web page.With theTUCAN data,
retrieved in the following month, we were
able to relocate 120 aftershocks occur-
ring in the first 5 days after the earth-
quake. Gustavo Reyes did much of this
analysis as an undergraduate intern at
Boston University. Locations are gener-
ally comparable to those determined by
INETER with slightly less scatter in
depth, as expected given the much denser
network (Figure 2). Strong secondary
arrivals arriving 3-10 s after the P wave
were commonly observed in Costa Rica,
at distances > 200 km. These signals may
reflect multipathing in the dipping sub-
ducting slab, and suggest that the data set
is rich in information about subducting
plate structure. Continued work is test-
ing the potential effects of three-dimen-
sional structure related to the slab on the
aftershock locations, a potentially signifi-
cant issue given that the events lie just
outside the array.
A preliminary point-source
deconvolution of 11 P and 4 SH waves
resolves an optimal depth for the earth-
quake of 26 ± 4 km and a very simple
moment-release history with most mo-
ment released within the first 16 s of rup-
ture. A more detailed body-wave
inversion technique provides information
on the full spatial extent of rupture
[Kikuchi and Kanamori, 1991]. Inputs
needed for the inversion include focal
mechanism, rise time and duration of
time functions, number of subevents, and
grid spacing; several iterations are per-
formed to determine the source param-
eters that produce synthetic seismograms
that best fit the observed data. The focal
mechanism from the Harvard CMT cata-
log (311° strike, 26° dip, and 98° rake)
and a trapezoidal time function (total time
of 6 seconds) provide the best fit to the
data. Using 12 P and 4 SH waves, the
optimal solution suggests a simple mo-
ment release history, with primary mo-
ment release approximately 10-20 km
northwest of the epicenter and second-
ary moment release at the epicentral lo-
cation and at ~40 km northwest of the
epicenter (Figure 1). Depth of moment
release occurs between 25-35 km. The
resulting source time function shows
moment release occurred within 20 sec-
onds, with total moment release of
2.8x1019
N•m, similar to the value pub-
lished in the Harvard CMT catalog
(3.0x1019
N•m).
We find that much of the moment re-
lease during the October 2004 event oc-
curred downdip of the rgional of large
moment release from the 1992 tsunami
event [Ihml, 1996]; moment release from
October 2004 does not overlap with the
1992 rupture. Aftershocks recorded by
the TUCAN network occurrws primarily
in the region of high slip, with some lo-
cated updip to ~15 km. The aftershocks
clearly define the dipping thrust zone in
this region of Nicaragua. In summary,
this data set reveals a fairly typical sub-
duction zone thrust event that probably
defines the downdip end of the
seismogenic zone near 35 km depth in
Nicaragua. This is somewhat deeper than
the downdip limit of 26-28 km beneath
northern Costa Rica near the Nicoya Pen-
insula [DeShon et al., in press], indicat-
ing that an important change in physical
properties of the thrust zone may accom-
pany the numerous other along-strike
contrasts between the two arc sections
[MARGINS Science Plans, 2004]. This
collaboration also shows the value-added
component of MARGINS studies: the
TUCAN array was deployed to image the
deeper parts of the Subduction Factory,
but clearly the data have relevance to
SEIZE goals as well.
References
Abers, G.A., L.Auger, E. Syracuse, T. Plank,
K.M. Fischer, C. Rychert,A.Walker, J.M.
Protti, V. Gonzalez, W. Strauch, and P.
Perez (2004), Imaging the subduction fac-
tory beneath Central America: The
TUCAN Broadband Seismic Experiment,
EOS Trans. AGU, Fall Meet. Suppl.
DeShon, H.R., S.Y. Schwartz, L.M. Dorman,
A.V. Newman, V. Gonzalez, M. Protti, T.
Dixon, E. Norabuena, and E. Flueh,
Seismogenic zone structure along the
Middle America Trench, Nicoya Penin-
“Nicaragua” cont. on Page 22Figure 2. Cross section A-A’ showing relocated aftershocks, using arrivals from TUCAN.
Cross section location shown on Fig. 1.

MARGINS Newsletter No. 15, Fall 2005 Page 3
The Subduction Factory Initiative: Status and Future Directions -
October 2005
Mark Reagan (Univ. of Iowa), Geoffrey A. Abers (Boston Univ.), Peter van Keken (Univ. of Michigan)
Initiative Summary
-88˚ -84˚
8˚
12˚
-88˚ -84˚
8˚
12˚
Nicaragua
Costa Rica
Crustal
Imaging
200
Planned
high-
res
seismic
50
100
150
Non-US
Refraction
Lines
Crustal
Imaging
Wide angle
profiles
Multi-
channel
Seismic
October
2005
SEIZE seismic station/OBS
Permanent/long-term
seismic station
TUCAN seismic station
Crustal imaging source
GEOMAR seismic station,OBS
and OBH deployments (Jaco,
4/02 to 10/02 and Quepos,
10/02 to 4/03)
Research funded by the Subduction Fac-
tory Initiative (SubFac) addresses funda-
mental questions about the mass flow
through convergent margins and the rela-
tive roles of mantle and subduction-de-
rived constituents in building continen-
tal crust.The fundamental science themes
include:
1. How do forcing functions such as
convergence rate and upper plate thick-
ness regulate production of magma and
fluid from the Subduction Factory?
2. How does the volatile cycle (H2
O and
CO2
) impact chemical, physical and bio-
logical processes from trench to deep
mantle?
3. What is the mass balance of chemi-
cal species and material across the Sub-
duction Factory, and how does this bal-
ance affect continental growth and evo-
lution?
Focus sites for researching these
themes were chosen by the community
to be the Central American and Izu-
Bonin-Mariana (IBM) subduction zones
(Figs. 1 and 2). Both have ample volca-
nic and seismic activity, accessibility to
samples for geochemical analyses that
document inputs and outputs, along-
strike variations in forcing functions,
cross-arc and historical perspectives, and
wide-ranging magma compositions. Cen-
tral America has particularly dramatic
variations in forcing functions and lava
compositions along strike from Nicara-
gua to Costa Rica. Extensive subduction
of organic-carbon bearing siliciclastic
and carbonate sediments beneath Central
America enables investigation of the car-
bon and water cycles through the sub-
duction zone, from slab to surface. The
IBM margin complements Central
America because it is subducting signifi-
cantly older lithosphere covered by a
crust with relatively thin and carbonate-
free sediment. The presence of active
back-arc volcanism and fore-arc mantle
serpentinization and fluid venting allows
output to be accessed across strike and
through time.
The first SubFac integrative effort was
the MARGINS-funded Theoretical and
Experimental Institute (TEI) held at the
University of Oregon in 2000, with key
contributions published in the AGU
Monograph “Inside the Subduction Fac-
tory” (Eiler, 2003). This TEI and volume
summarize our understanding at the on-
set of SubFac, and forms the baseline for
progress. In this interim report we will
provide an overview of research spon-
sored by the Subduction Factory Initia-
tive, focusing in particular on the
geochemical and geophysical field stud-
ies at the two focus sites.
Mass fluxes through the
Central American arc
MARGINS-funded projects quantify-
ing the input and output of the Central
American arc have produced a number
of significant publications over the past
few years. Studies of Li isotopes by Chan
et al. (2002) and O isotopes by Eiler et
al. (2005) have shown that Nicaraguan
lavas, which have long been known to
have an exceptionally high proportion of
subducted constituents (e.g., Carr, 2003),
have a combination of heavy Li and light
O. This suggests that most of the trans-
ported mass from the slab is in water-rich
fluids from subducting basaltic crust and
Figure 1. Major seismic experiments in the Subduction Factory/Seismogenic Zone Central
America Focus Site. (Adapted from MARGINS Office Focus Site map available from:http://
margins.wustl.edu/ResearchResults.html)

MARGINS Newsletter No. 15, Fall 2005
142 144 146 148
12
14
16
18
142 144 146 148
JAMSTEC active source
refraction line
Anatahan
October 2005
Other OBS
EW0203 OBS
Shiptrack
(EW0203 and
COOK07MV)
Onland seismic
station
Initiative Summary
serpentinized mantle. A deep source for
this water in subducted crust was
seismically imaged by Abers et al.
(2003), and is consistent with both cal-
culated seismic velocities for hydrated
subducted crust in the form of lawsonite
eclogite (or perhaps serpentinized
mantle) and seismic velocities predicted
for subduction zones (Connolly and
Kerrick, 2002). Pb isotope compositions
(Feigenson et al., 2004), U-series and Th
isotope data (Thomas et al., 2002), and
variations in O isotope values across
Central America (Eiler et al., 2005), to-
gether with 10
Be data (e.g., Morris et al.,
1990) indicate that a separate water-poor
component derived from sediment also
is involved in magma genesis beneath
Nicaragua. Plank et al. (2002) estimate
that 75% of thorium from this sediment
consistently has been recycled into lavas
since 20 Ma, indicating at least 75% of
sediment subducts past the forearc.
Considerable advances also have been
made in estimating fluxes of magmatic
volatiles out of Central American volca-
noes. He-C relationships in gases from
fumaroles and hot springs indicate that
the flux of carbon from the subducting
slab to the surface increases from Costa
Rica to Nicaragua. This reflects the en-
hanced sediment recycling beneath Nica-
ragua compared to Costa Rica.
Nevertheless, the total flux of carbon
from the slab to the surface as CO2
be-
neath Central America is about half that
of other arcs despite the high rate of sub-
duction of carbonate and organic carbon,
which implies that as much as 85% of
the carbon in sediments subducts past the
Central American volcanic front to the
deep mantle (Shaw et al., 2003). Nitro-
gen recycling from subducting sediment
is unusually low in the Costa Rican seg-
ment of the arc compared to Nicaragua
and other arcs, and provides further evi-
dence of weak sediment recycling be-
neath Costa Rica (Zimmer et al., 2004).
Mass fluxes through the
Izu-Bonin-Mariana arc
Volatile contents across the Izu-
Bonin-Mariana arc are being investigated
in several novel ways. Studies of pore
waters from serpentine mud volcanoes in
the forearc show that carbonate alkalin-
ity, sulfate, Na/Cl, K, Rb, Cs, and B all
increase away from the trench as tem-
perature increases at the top of the sub-
ducting plate, suggesting that the depth
of the 150°C isotherm in sediments be-
neath the forearc is 17-22 km (Mottl et
al., 2004). Studies of volatile concentra-
tions and selected isotopic compositions
in glass inclusions in olivine crystals from
active arc lavas are quantifying volatile
fluxes through the IBM arc, as well as
compositions of endmember mantle-de-
rived and subduction-derived compo-
nents (e.g., Kelley and Plank, 2005; Shaw
et al., 2005; Fischer et al., 2005; Kent
and Crowe, 2004; Kent and Gill 2005).
Results suggest a role for decompression
melting of the mantle as well as fluid-
fluxed melting to produce the lavas, and
may indicate carbonate contribution from
the subducting altered oceanic crust.
Ongoing studies of compositions of
submarine glasses from the Mariana
Trough and other back-arc lavas are
quantifying the degree of involvement of
water and other subducted constituents
in the backarc and the relative roles of
fluxed versus decompression melting
(e.g., Kelley et al., submitted).Additional
constraints on pressure, temperature, and
H2
O content of magmas from the IBM
arc system are being determined through
experimentation on natural samples (e.g.,
Grove et al., 2004).
Geochemical studies of lavas erupted
throughout the history of volcanism in
the Mariana arc are finding that the
Figure 2. Major seismic experiments in the Marianas portion of the Subduction Factory Izu-
Bonin-Marianas Focus Site. (Adapted from MARGINS Office Focus Site map available from:
http://margins.wustl.edu/ResearchResults.html)

“SF” cont. on Page 19
change from early boninitic volcanism to
more typical tholeiitic and calcalkaline
volcanism occurred over a several mil-
lion year period, documenting the change
from mantle upwelling at arc initiation
caused by catastrophic sinking of the
Pacific plate (Hall et al., 2003; Stern,
2004) to normal mantle convection as-
sociated with steady-state subduction
(Reagan et al., 2003). In May 2004, Japa-
nese and MARGINS-funded scientists
from the USA used the R/V Yokosuka
and its Shinkai 6500 submersible to col-
lect a late Eocene section of
volcaniclastic rocks cropping out along
the eastern escarpment of the Ogasawara
Trough near the Bonin Islands (Bloomer
et al., 2004; Ishizuka et al. 2005). Addi-
tional diving by the same group to inves-
tigate the architecture of the arc crust and
underlying mantle southeast of Guam is
scheduled for 2006.
Anatahan Event Response
MARGINS-funded scientists staged
rapid responses in May 2003 and March
2004 to eruptions ofAnatahan, the south-
ernmost volcanic island of the active
Mariana arc (see the reports in MAR-
GINS Newsletters 12 and 14). Research
on samples and data collected on the
eruption in 2003 is presented in a special
issue of Journal of Volcanology and Geo-
thermal Research entitled: “The 2003
Eruption ofAnatahanVolcano, Common-
wealth of the Northern Mariana Islands”
(Hilton et al., 2005, see p. 22). Publica-
tions of MARGINS-funded projects in
this issue included studies of seismicity
(Pozgay et al., 2005), degassing (de Moor
et al., 2005), and geochemistry of the
lavas (Wade et al., 2005; Reagan et al.,
2005).The principal implications of these
studies from a volcano hazards perspec-
tive are that significant eruptions of
andesite in arc volcanoes can be preceded
by very little seismicity, and that the dif-
ferentiation from basalt to silicic andes-
ite can happen in less than a few thousand
years. In addition, Wiens et al. (2005)
were able to extract a rare tilt signal from
theAnatahan seismic data, which they di-
rectly related to magmatic inflation dur-
ing the eruption. These studies also have
shown that Anathan’s andesite was gen-
erated largely by crystal fractionation of
a parental basalt that was generated in the
mantle after it received about a third of
the sediment that is presently subduct-
ing beneath Anatahan.
Geophysical investigations
of the focus sites
Geophysical imaging complements
geochemical studies of input and output
by providing in situ sampling of the Sub-
duction Factory at work. Seismic and
electromagnetic measurements provide
proxies for temperature, fluid abundance,
the geometry of the main interfaces and
their relationship to the generation of
earthquakes in the slab. Active-source
seismic experiments also provide basic
constraints on crustal growth, tectonic
evolution, and bulk composition of the
crust. At both focus sites, the nominal
suite of experiments include seismic re-
flection images of the upper crust, large-
offset imaging of the arc crust,
earthquake-seismic experiments de-
signed to image the subduction system
at mantle depths, magnetotelluric experi-
ments designed to map out mantle con-
ductivity structure, and heat flow
measurements (Table 1).
In the Marianas, a joint U.S.-Japan
project is underway and provides a full
suite of seismic measurements (U.S. PI’s:
Taylor, Klemperer, Wiens). The project
includes reflection imaging of fore-arc
Table 1 MARGINS-funded projects: The Subduction Factory
Focus P.I. Start End Short Title
Geochemistry
Centam Carr 8/1/2005 7/31/2006 Volcanic growth rates
Centam Garrison 9/1/2004 8/31/2006 Rhyodacite differentiation
Centam Walker, Hirschmann 6/1/2004 5/31/2005 Centam magmas
Centam Carr 7/1/2002 6/30/2004 CentAm volcanic fluxes
Centam Eiler 8/1/2001 7/31/2004 CentAm O isotopes
IBM Goldstein 5/1/2005 5/31/2007 Eocene-Oligocene IBM
IBM Stern 6/1/2004 5/31/2009 IBM inputs
IBM Kent 7/1/2003 6/30/2006 Izu melt inclusions
IBM Hauri, Fischer, Hilton 6/15/2003 5/31/2006 IBM output fluxes
IBM Hanan, Hickey-Vargas,
Reagan
1/1/2001 12/31/2003 Early Marianas
IBM Grove, Stolper, Plank 9/1/2000 8/31/2003 IBM Volatiles
IBM Stern, Bloomer, Clift 9/1/2000 8/31/2003 IBM inputs
Gaetani 7/1/2001 6/30/2004 Hydrous melt experiments
Chan 9/1/1999 8/31/2002 Li isotopes
Geodynamics
Hirth, Evans 5/15/2004 4/30/2007 Lithosphere rheology
Conder 7/1/2003 6/30/2005 Numerical melting models
Kerrick 6/1/2003 5/31/2005 Metamorphic devolatilization
Hirth 5/15/2002 4/30/2004 Mantle wedge convection
Van Keken 10/1/2002 11/1/2002 Workshop on subduction
zone thermal structure
Kincaid 8/15/2001 7/31/2003 3-D lab flow models
Kerrick 8/15/1999 7/31/2002 Metamorphic decarbonation
Geophysics and Marine Geology
Centam McIntosh 6/15/2005 5/31/2007 Nicaragua lakes reflection
Centam Holbrook, Lizarralde,
Kelemen, van Avendonk
11/15/2004 10/31/2009 CentAm crustal imaging
Centam Lonsdale 1/1/2003 12/31/2004 CentAm sea floor mapping
Centam Brown 5/1/2002 12/31/2004 CentAm benthic fluxmeter
Centam Abers, Fischer 4/1/2002 3/31/2006 CentAm broadband seismic
Centam Fisher, Stein, Harris, Wheat 10/1/2000 9/30/2004 CentAm marine heat flow
Centam McIntosh, Silver 1/1/2000 12/31/2002 CentAm marine reflection
IBM Chave 6/1/2004 5/31/2008 IBM Magnetotellurics
IBM Fouch 7/1/2003 6/30/2005 IBM anisotropy and flow
IBM Taylor, Wiens, Klemperer,
Hildebrand
10/1/2001 9/30/2005 IBM multi-scale seismic

MARGINS Newsletter No. 15, Fall 2005 Meetings Update
Waipaoa Source to Sink Participants Hold
Science and Planning Meetings
Clark Alexander, Phil Barnes, Kelvin Berryman, Kate Bodger, Hannah Brackley, Lionel Carter, Lila Gerald,
Tommy Gerber, Steve Kuehl, Nicola Litchfield, Jesse McNinch, Alan Orpin, Alan Palmer, Jarg Pettinga,
Lincoln Pratson, Noel Trustrum and J.P. Walsh contributed data to this summary of Waipaoa research pre-
sented at the New Zealand Marine Sciences Society MARGINS session.
Within the MARGINS Program, the
Source to Sink (S2S) Initiative is foster-
ing greater understanding of complete
sedimentary systems, extending from
upland sediment sources to deep-sea
sediment sinks. The Waipaoa Sedimen-
tary System (WSS) located on the east
coast of the North Island, New Zealand,
is one of two S2S focus sites, and saw
MARGINS-funded field work begin on
the continental margin in January and
February 2005 (see focus area map and
study regions at the MARGINS Website
< m a rg i n s . w u s t l . e d u / R e s e a r c h
Results.html>). Because of the solid sci-
entific background developed by New
Zealand researchers in the area and the
initial cruise observations and measure-
ments, significant new insights into the
WSS are already beginning to be avail-
able and strategic planning based on these
results is ongoing. These results are be-
ing disseminated beyond the individual
international MARGINS collaborators at
international conferences and through
educational websites (e.g., http://
coastal.geology.ecu.edu/nz/index.php).
In August 2005, results from the
Waipaoa focus site were presented at the
international “Human Impacts in the Ma-
rine Environment” meeting run by the
New Zealand Marine Sciences Society
in Wellington, NZ. Julie Morris of the US
MARGINS Office opened the dedicated
session by giving an overview of the
MARGINS Initiative. Steve Kuehl (Vir-
ginia Institute of Marine Science -VIMS)
presented the Keynote talk in the session,
introducing the MARGINS S2S Initia-
tive and the specific characteristics of the
WSS that make it a highly suitable site
for addressing S2S research questions.To
start off the disciplinary session, Chuck
Nittrouer summarized the state of knowl-
edge for the second S2S Focus Site, the
Fly River/Gulf of Papua, Papua New
Guinea, so that details of the WSS pre-
sented later could be compared and con-
trasted, in line with the MARGINS
philosophy.
Major sources of new data for the
WSS included two cruises to theWaipaoa
margin in January and February 2005 on
the RVKilo Moana, focusing on shelf and
slope sedimentary processes, respec-
tively. Radiochemical and sedimentologi-
cal results confirm the presence of three
modern sediment depocenters on the
shelf: two on the midshelf, one north and
one south of the river mouth; and a third
on the outer shelf that had been previ-
ously identified. In each of these
depocenters, accumulation rates approxi-
mate 1 cm/y. Interestingly, the strati-
graphic character of the depocenters
differs such that the midshelf depocenters
preserve physical stratification and ter-
rigenous input signals, whereas the outer
shelf depocenter is more homogeneous.
Modern sediment is also escaping the
shelf to accumulate in some submarine
canyons on the upper slope, at rates simi-
lar to those in the shelf depocenters. Al-
though sedimentary organic matter is
discharged from the river along with the
lithogenic particles that transit the mar-
gin, there is a depletion in terrestrial or-
ganic carbon seaward across the margin
and a commensurate increase in marine
organic carbon content. Dispersal mecha-
nisms through the WSS are still poorly
understood and require additional study
to identify relevant sources of material
to and transport pathways within the
study area.
Upcoming MARGINS fieldwork to
document shoreline progradation and
sediment exchange between the coastal
plain and inner shelf has recently been
funded by NSF and will extend the in-
vestigation of the WSS from the conti-
nental slope across the land/sea boundary.
As the study moves up into the drainage
basin, increasing knowledge of the influ-
ence of tectonic setting on sediment sup-
ply (e.g., via tectonic erosion, regional
tilting and nickpoint retreat) will grow
in importance.
The session ended with a compara-
tive discussion of the Waipaoa and Fly
systems, drawing on the new results pre-
sented earlier in the day and the pre-ex-
isting information that initially identified
the WSS as an appropriate S2S Focus
Site. Several characteristics were com-
mon to all potential focus sites, includ-
ing: a closed system; strong forcing
producing strong signals; active sedimen-
tation within and transfer between com-
partments of the dispersal systems
producing a high-resolution record; ad-
equate background data and infrastruc-
ture; and manageable logistics. In
addition, the WSS exhibits characteris-
tics of: a strong upland input signal from
natural sources, particularly earthquake-
triggered landslides, and anthropogenic
sources (i.e., European colonial defores-
tation); strong cyclonic meteorological
forcing and basin response; a well-con-
strained point source for input of this flu-
vial material to the sea; frequent and
spatially extensive volcanism that pro-
vides outstanding geochronological con-
trol through uniquely identifiable and
well-dated tephra horizons; and signifi-
cant lake and paleo-lake deposits contain-
ing records of climatic and tectonic
activity spanning the past 30 ka, which
can be compared to continental margin
sedimentation over the same time period.
The WSS was also characterized as an
analogue to the Eel River System in the
US, which will be the proposed site of a
MARGINS S2S TEI in late 2006.
The day following the open scientific
session, the National Institute of Water
and Atmospheric Research (NIWA)

hosted a one-day workshop at their Greta
Point facility to assess the state of the
Waipaoa S2S Initiative and to identify
gaps in the Science Plan based on dis-
cussions from the previous day. Presen-
tations were made highlighting the
progress and goals for each of the four
S2S sectors (i.e., uplands source, flood
plain/coast transition, continental shelf
and continental slope sinks).
For the uplands source, much is al-
ready known from previous research
about shallow landslide and gullying pro-
cesses, although the timing and duration
of these processes are less well under-
stood. The major issues for source term
field researchers and modelers is the char-
acter and timing of major landslides:
How often do they occur? Do they pro-
vide a pulse, steady perturbation or a
post-event pulse that moves through the
system? How do they affect sediment
delivery? This information will become
even more critical when extending the
timescale of interest to the Last Glacial
Maximum (LGM) and beyond, as the cli-
matic conditions change significantly.
Work has only recently been funded
to investigate the region of the floodplain/
coastal transition. The major goals within
that sector will be to more precisely de-
termine coastal progradation history, to
determine the effect of natural and hu-
man changes in the river geometry and
to prepare for and carry out rapid re-
sponse cruises to better understand the
dispersal of material from Poverty Bay
onto the shelf.
The continental margin, specifically
the shelf and slope sectors, have been
research foci in the past year. Identifi-
cation of discrete shelf depocenters, some
of which are preserving a terrestrial sig-
nal, illustrates the need for longer cores
in the three depocenters and an under-
standing of biological markers in the
record (i.e., palynomorphs, microplank-
ton and organic carbon). Additionally,
analysis of existing sidescan data needs
to be performed to help determine shelf
transport pathways. For the slope sector,
discovery of significant off-shelf trans-
port to the upper slope highlights the need
to understand circulation and transport
processes near the shelfbreak. With sig-
nificant material accumulating on the
comparatively steep slope, the roles of
mass wasting and lower slope sediment
transport also need to be addressed.
As illustrated by the discussion above,
the gaps in our current science plan for
all four of the sectors in the WSS focus
on two topics: tectonics and transport.
Although these two topics are relevant
to all four sectors of the WSS, different
specific needs exist within each sector.
For all sectors, a thorough understand-
ing of the detailed tectonic history of the
Waipaoa drainage and margin is neces-
sary in order to unravel the signatures of
sediment supply, changing basin geom-
etry and shelf/slope mass wasting. For
the upland sector, filling gaps requires a
synthesis of existing terrace age datasets
with other existing paleorecords, the pro-
duction of river discharge histories in
relation to changing climate and land-
scape, and a synthesis modeling effort.
For the floodplain/coastal transition, shelf
and slope sectors, filling gaps will require
both observations and modeling of cir-
culation and sediment transport processes
at the coast and on the continental mar-
gin.
During general discussions, the group
was apprised by Geoffroy Lamarche that
the French RV Marion Dufresne II would
be in NZ waters in January 2006. This
ship is capable of retrieving piston cores
up to 58 m long, which could provide
opportunities to examine the LGM sedi-
ment record on the slope and shelf. It was
agreed that Kuehl and Alexander would
write supplemental proposals to NSF to
pursue this opportunity, requesting sup-
port to collect 5 cores, one from each of
the shelf depocenters and two from the
slope (for which funding has subse-
quently been awarded). In addition, a
consensus was reached to quickly de-
velop an event response plan for the
WSS, to be executed in the event of a
cyclone during the MARGINS study pe-
riod.
MARGINS Rupturing Continental Lithosphere Workshop
“Lithospheric Rupture in the Gulf of California-Salton Trough Region”
Ensenada, Mexico, January 9-13, 2006
After receving enthusiastic international response, the final stages of planning are currently progressing for this MAR-
GINS-sponsored workshop to be held January 9-13, 2006, in Ensenada, Mexico. The workshop will focus on lithos-
pheric extension, crustal deformation, seafloor spreading, magmatism, basin formation, and upper-mantle processes
that ave operated through time to shape the active oblique-rift system of the Salton Trough Region.
Although applications closed a couple of months ago, post-meeting additions to the workshop website (www.rcl-
cortez.wustl.edu) will include: presentation PowerPoints; a workshop report; and information on major outcomes of
discussion on synthesis and future directions.
Workshop abstracts will also soon be posted on the meeting website.

It’s with a certain sense of irony that I
note two things affecting MARGINS,
which are happening almost simulta-
neously. MARGINS science is flowering
across all the initiatives, and synthesis
work within each of the focus sites is well
underway.At the same time, flat funding
± at NSF together with increased fuel
costs and the retirement of the R/V Ewing
is significantly limiting continuing MAR-
GINS research as MARGINS heads into
its seventh year of funding. I’ll talk about
the status of the initiatives in a minute,
but let me turn first to the funding situa-
tion as I understand it.
NSF Funding Levels
The increasing cost of ship operations
makes the Ocean Sciences Division par-
ticularly vulnerable to the negative im-
pacts of flat funding. In an attempt to deal
with this issue, NSF asked UNOLS to
prepare a series of recommendations for
their consideration (see www.unols.org,
UNOLS Recommendations on how to
Address the Impact of Declining Budget
Levels on Fleet Operations). The report
clearly notes that budget cuts severely
limit researcher access to the sea and are
highly detrimental to effective research.
That said and universally agreed, the re-
port contains a series of recommenda-
tions. One is intended to keep ships and
crews together and functioning as much
as possible through partial rather than
total lay-ups. Another is to continue de-
veloping new capability for the fleet (e.g.,
complete the refitting of the R/V
Langseth, with its 3-D seismic capabil-
ity), but slow the pace of development to
spread costs over additional years.Acon-
sequence for MARGINS researchers is
that high quality and important propos-
als may be declined or ship time with-
held until further in the future. From my
discussions with program officers and
various PIs, I believe that investigators
in core programs and other special ini-
tiatives such as R2K are sharing the same
fate.
Are there any bright spots or solutions
for MARGINS? I’m afraid that we’re in
for at least several more lean years, which
will require patience and persistence. The
U.S. Commission on Ocean Policy Re-
port (www.oceancommission.gov), de-
livered to the President and Congress last
year, highlights many aspects of mostly
applied research that are important to the
health and well-being of the oceans and
the country.Among these are hazards and
resources, which have been explicit parts
of the MARGINS Science Plans from the
get-go. While our focus will not be on
mapping hazards or quantifying reserves,
any number of relevant topics grow out
of our science (e.g, investigations of
earthquake triggering and fracture propa-
gation mechanisms by the SEIZE initia-
tive). It’s perhaps worth asking your NSF
program officer about the level of inter-
est in proposals that include hazards or
resources. More importantly, all of the
initiatives are ripe for more theoretical
and experimental investigations. The
MARGINS panel has always recom-
mended these types of proposals, but now
may be an especially good time for fi-
nancial reasons (reduced ship time) and
to make use of the large amount of sci-
ence now becoming available from ear-
lier MARGINS funding. In addition to a
more integrated understanding of the
problem at hand, such efforts could high-
light the essential missing data types nec-
essary to resolve critical issues.
NSF-MARGINS Panel
You may know that as MARGINS
Chair, at NSF invitation I have presented
brief summaries of MARGINS activities
before the start of last two MARGINS
panels, without any knowledge of the
proposals submitted or their content. My
presentations have been based on MAR-
GINS Steering Committee (MSC) dis-
cussions, information provided by the
PIs, and what I learn through attending
workshops and special sessions.As such,
my viewpoints are informed, but also
shaped by the perceptions and judgments
of the MSC and myself. However, these
form only a small part of the input that
the panel and program officers receive
from multiple sources, which they weigh
and use as they see fit. As background
for the panel, we update the MARGINS
focus area maps (www.margins.wustl.
edu/ResearchResults.html) and compile
lists of funded proposals in each of the
focus areas, together with their abstracts
(published in the Spring Newsletter each
year and available at www.margins.wustl.
edu/NSF-MARGINS/AwardNum.html).
In the presentation itself, I present a few
snippets of new science in each of the
initiatives, culled from what you provide,
what I see at meetings or in journals, and
what comes to the MSC. I also summa-
rize recognized research gaps in each of
the initiatives and highlight upcoming ac-
tivities. The research gaps are those iden-
tified by the MSC in preparation for the
NSF-MARGINS review last year
(www.marginsreview.wustl.edu/
InitiativeSumm.html, and look for the
subsection headed Research Gaps),
modified by the publicly available infor-
mation about proposals funded since that
time. Two articles in this Newsletter
(SubFac Initiative status and future di-
rections, p. 3; and a report on S2S New
Zealand science and planning meetings,
p. 6) speak to this topic, and are discussed
below. I iterate all this for several rea-
sons: I believe in transparency; I want to
encourage your cooperation in updating
the MARGINS Office and MSC on your
research accomplishments; and I want to
give you the opportunity to let the MSC
know if you feel that having the Chair
speak to the MARGINS panel is inap-
propriate. However, I’m completely con-
fident in myself that this is an extremely
useful activity, is well appreciated by the
NSF panel, and violates no confidential-
ity, but I’d like to hear from you
From the MARGINS Chair - Fall 2005
Julie Morris, Dept. of Earth and Planetary Sciences, Washington University in St. Louis, MO 63130, USA
E-mail: jmorris@wustl.edu
From the Chair

(jmorris@levee.wustl.edu) if you think
differently.
Status of the Initiatives
We began including a regular update
in the Newsletter on the status of the ini-
tiatives a year ago. Our reasoning is that
you should also hear the discussions on
how work is progressing in each initia-
tive that are available to NSF program
officers. Each Newsletter, a subset of the
MSC is asked to write a short article on
progress within an initiative, and we ro-
tate through the four areas of study.
Subduction Factory.Asubstantive ar-
ticle in this Newsletter reviews progress
in the SubFac Initiative (see p. 3). Since
the NSF-MARGINS review of a year
ago, proposals have been funded for ac-
tive and passive source seismic studies
of CentralAmerican crustal structure, and
for additional studies of the incoming
plate, with work well underway. Studies
of hydration of the shallow incoming
oceanic plate off Costa Rica are under-
way through ODP Leg 205 and IODP
Expeditions 301T and 312. A
magnetotelluric study of the IBM system
will commence in Dec. 2005. As noted
previously, most of the big-ticket marine
surveys have now been funded and par-
tially completed for the SubFac Initiative.
Observationally, modern systematic heat
flow studies that extend across the arc
remain to be done, along with further
studies of magma and volatile fluxes and
selected petrological and geochemical
studies. Conceptually, topics such as ini-
tiation of subduction, development of the
intrusive part of the arc system, and the
extent of serpentinization of the deep part
of the incoming plate are becoming in-
creasingly important. As noted by the
MSC, integration and synthesis and theo-
retical modeling are now very high pri-
orities for SubFac; the AGU special
session on the IBM system (Izu-Bonin-
Mariana Subduction Factory Studies,
T44A, T53A) is a step in that direction.
Seismogenic Zone.The SEIZE experi-
ment is also progressing nicely, with
IODP proposals for riser- and riserless-
drilling off Nankai and off Costa Rica
moving through the advisory structure.
A joint Japan-US study will carry out 3-
D seismic work in the Nankai region in
2006. In 2004, a proposal was funded to
establish a sparse continuous GPS back-
bone for Central America.
Observationally, a long-term OBS de-
ployment remains to be done in Central
America. The MSC notes the importance
of additional laboratory studies of mate-
rial properties, frictional heating,
physico-chemical processes for rate-de-
pendent friction, consolidation and meta-
morphism, and theoretical or
experimental studies of earthquake nucle-
ation and propagation. Another very im-
portant topic is thermal modeling and
integrated thermal-hydrological, -chemi-
cal, and -deformation modeling, includ-
ing temporal variations through the
seismic cycle. The MARGINS special
session at AGU (Fluids at Subduction
Zones: Integrating Models and Observa-
tions Within MARGINS and Related
Studies, T11E, T12B, T13B) speaks to
some aspects of this topic.
Rifting of Continental Lithosphere.
Much of the observational work planned
for the Gulf of California (GoC) site is
underway or nearing completion and will
be presented at a MARGINS workshop
in Ensenada, Mexico, Jan. 9-13, 2006,
convened by Becky Dorsey, Raul Castro,
John Fletcher and Dan Lizarralde. Oct.
2005 saw installation of a 15 month OBS
deployment in the GoC. Beyond what has
already been done, there is currently no
active source seismic work for the north-
ern Gulf, a result of marine mammal
complications. High-resolution seismic
work is needed in the S. Gulf. Some as-
pects of the neo-tectonics remain to be
worked out, along with the extended his-
tory of rifting in the region (12-13 Myr
history, and locally as long as 15-20 Myr
history).At the workshop in January, one
underlying goal will be to evaluate the
complete package of achievable work in
the region (taking into account permit-
ting issues) and assess the quality and
import of the science that can be accom-
plished. Another concern will be to inte-
grate as much as possible with
Earthscope efforts in adjoining regions.
The great beauty and natural significance
of the Gulf of California was recently
formally recognized in the creation of the
UNESCO Islands and ProtectedAreas of
the Gulf of California World Heritage
Site (http://whc.unesco.org/en/list/1182).
We hope that this designation will in-
crease public, visitor and government
interest in understanding the history and
origins of the region’s unique features,
but also recognize that it remains critical
that researchers not only maintain aware-
ness of enviro-political concerns, but also
be conspicuously seen to do so.
In the Red Sea, a Euro-MARGINS
cruise in Dec. 2004 - Jan. 2005, with
Enrico Bonatti as chief scientist, was able
to do some bathymetry mapping and
dredging in the central region. US funded
efforts include a thermochronology study
in Saudi Arabia, a GPS study in Saudi
Arabia and Eritrea, with stations to be
deployed in Egypt soon, and a tomo-
graphic study using results from Saudi
seismic stations, IRIS permanent stations
and a 1996 PASSCAL deployment.
Source to Sink. S2S investigators are
moving very quickly in both the Gulf of
Papua (Papua New Guinea) and Waipaoa
(New Zealand) focus areas.An extensive
array of coordinated cruises was carried
out in Papua in 2004 and in the Waipaoa
region earlier this year. Results have been
summarized at a number of special ses-
sions at GSA2004,AGU 2003 and 2004,
and the New Zealand Marine Conference
2005, with upcoming sessions at the 2006
AAPG meeting and AGU Ocean Sci-
ences meeting. Specific progress and re-
search needs for the Waipaoa region are
nicely summarized in the article entitled
“Update on Waipaoa Source to Sink Sci-
ence and Planning Meetings” on p. 6 of
this Newsletter. Recent work in Waipaoa
highlights the importance of tectonic
sedimentation in the region, and the ex-
istence of long stratigraphic records on
land and at sea of changing climate and
tectonic conditions, well constrained by
tephrochronology. In the Gulf of Papua,
work continues on topics such as the sedi-
ment fluxes from the Fly River vs. the
“Chair Report” cont. on Page 21

Over the last decade NSF has sponsored
several workshops of the sediment dy-
namics and sedimentary geology com-
munity to develop a unified vision for the
creation of a surface dynamics modeling
system with the capability to predict the
erosion, transport and accumulation of
sediments and solutes from the source of
the sediments in the uplands to their ulti-
mate sink in the deep sea. The commu-
nity has concluded that they need to de-
velop a community wide surface-dynam-
ics modeling “environment” containing
a suite of interconnected and integrated
software modules capable of predicting
the transport and accumulation of sedi-
ment and solutes in landscapes and sedi-
mentary basins over a broad range of tem-
poral and spatial scales. The science plan
of the MARGINS Program’s Source-to-
Sink initiative underscores this need and
advocates a community sediment mod-
eling effort that deals with the source to
sink system of environments in its en-
tirety. On-going MARGINS experiments
may provide the necessary observational
underpinnings for testing the resultant
system of integrated models. An earlier
“Future of Marine Geology and Geo-
physics” report of the Earth Science com-
munity to NSF also decried the lack of
linkages between models dealing with
various components of the system and
identified this as a major barrier to the
advancement in surface processes re-
search.The report strongly recommended
the development of integrated sediment
models at a range of time scales involved
in surface processes, covering all sedi-
ment features and morphologies by a se-
ries of linked models into a unified whole
that would lead to a general theory of
sedimentation based on the fundamental
principles. Supporting documents for
these recommendations can be found in
following websites and reports:
• The Community Surface-Dynamics
Modeling System Strategy and Rationale
http://instaar.colorado.edu/deltaforce/
workshop/version4_04.pdf
• Community Surface-Dynamics Model-
ing System Science Plan
workshop/CSDMS_science_ plan_
v6.pdf
• Community Surface-Dynamics Model-
ing System Implementation Plan
workshop/CSDMS-implementation-
final.pdf
• “The Future of Marine Geology and
Geophysics” Report of a workshop to
National Science Foundation, pp. 47-70,
1997.
• “MARGINS Science Plans, 2004” pp.
131-157, also available on website of the
MARGINS Program
http://www.marginsreview.wustl.edu/
SPHome.html
In response to these needs and com-
munity recommendations NSF will ac-
cept proposals from the community for
joint consideration by the Divisions of
Earth and Ocean Sciences for the estab-
lishment of an organizational infrastruc-
ture (OI) to be considered within their
existing GeoInformatics (administered
by the Instrumentation and Facilities Pro-
gram) (GI) and MARGINS Program so-
licitation frameworks, respectively.
The organizational infrastructure (OI)
will form a nucleus responsible for the
construction of the overarching architec-
ture of the surface-dynamics modeling
environment and must meet several chal-
lenges that include: a multiplicity of
fields, scales, interests and applications;
a central role of testing the modules
against data; the coverage of a wide
breadth of surface processes; product
delivery in a timely manner; and national
community reach. It will house the core
server and some of the essential manage-
ment, computational and educational
staff necessary to advance the CSDMS
initiative. Other active participants may
be distributed elsewhere in other institu-
tions.
It is envisioned that the OI will be re-
sponsible for: 1) Creating and maintain-
ing the computational system, 2)
Ensuring compatibility, portability and
interoperability of modules, 3) Ensuring
clarity/consistency of documentation,
interfaces, code, 4) Ensuring computa-
tional efficiency of system code, 5) Sup-
porting working groups/nodes and
individual scientists with on-site and off-
site (virtual) training, topical workshops,
and other meetings, 6) Linking to other
national computational resources, and 7)
Education and knowledge transfer to the
community and public. The OI may also
propose demonstration project(s) vital to
their overall mission.
The OI will also have a central role in
enabling working group nodes that will
represent the knowledge base, and will
be responsible for creating and manag-
ing the various process modules and pro-
viding continuity to meet long-term
project objectives. The working groups
will be set up to solve integrated prob-
lems outlined in the science plan, iden-
tify gaps in knowledge, and foster
inter-disciplinarity within and between
groups. As “keepers of the code” these
groups will identify the tools and/or pro-
cesses that populate the various disciplin-
ary toolkits. They will be responsible for
quality control for the algorithms and
processes that are included for their area
of expertise. They will set the priorities
for modeling within a discipline, and fa-
cilitate the movement of these priorities
up the hierarchy from technology groups
to OI and the Steering Committee. Thus,
the responsibilities of the working groups
include: technical quality control; ad-
equacy of testing; evaluating the codes
according to interoperability criteria; set-
ting scientific priorities for the group;
N.S.F to accept Proposals for the Development of “CSDMS”
Organizational Infrastructure
Bilal Haq, National Science Foundation
“CSDMS” cont. on Page 22
CSDMS

This summer, Dr. Rosemary Hickey-
Vargas enthusiastically agreed to serve
on the newly formed MARGINS Educa-
tion and Public Outreach (MEPO) Com-
mittee.As a MARGINS scientist who has
shown her mettle in the field of educa-
tional outreach and as a Subduction Fac-
tory Principal Investigator (PI), we were
delighted when she agreed to be inter-
viewed for this edition of the MARGINS
Newsletter.
A long-time
investigator of
convergent mar-
gin magmatism,
Rosemary star-
ted as a faculty
member at Flor-
ida International
University (FIU)
after completing
her doctorate and
post- doctorate at
MIT. From 2001
to 2004 she was
FIU Department
Chair. Her NSF-
Geosciences fun-
ded research has
especially focu-
sed on the early
Izu-Bonin-Mar-
ianas (IBM) Arc
and the southern
Andes, including
a recently com-
pleted MARGINS-funded collaborative
research project: OCE 00-01826: Magma
generation in the early Mariana Arc sys-
tem revisited, with co-PIs Mark Reagan
(U. Iowa) and Barry Hanan (San Diego
State).
Having a son in Miami public educa-
tion is what first drew Rosemary into
expanding her outreach activities. See-
ing how he benefited when other scien-
tists and professionals made the effort to
communicate with his school and teach-
ers inspired her to run an annual online
geoscience contest for local high school
science students duringAGI’s Earth Sci-
ence Week. That was 1998, and the con-
test is still running. As FIU Department
Chair, the practical motivation to recruit
new geoscience majors further opened
her perspective on outreach opportuni-
ties.
It was during Rosemary’s term as De-
rel Collins, Michael Gross, Andrew
Macfarlane, Rene Price and Dean
Whitman.
These faculty recognized that many
incoming undergraduates overlook the
FIU geoscience major simply because
they have not been exposed to the diver-
sity of the field, or do not know that it
can open up a range of relatively high
paying, socially useful careers. Thus
GeoSCOPE
would focus
on attracting
science-ori-
ented fresh-
man and
sophomores
from under-
represented
groups into
the geoscien-
ces at FIU
and Miami
Dade Com-
munity Col-
lege.
Each sum-
mer, the pro-
gram opens
with around
twenty in-
terns, drawn
from science
courses, par-
ticipating in
short two-
week faculty-taught workshops that (cru-
cially) bring them up to speed on
geoscience topics and research methods.
These workshops lead directly into in-
ternships working in research labor-
atories in the FIU Earth Sciences
Department for about six weeks. At the
end of the internships, a dedicated sym-
posium allows the interns to present and
share their research results from across
the breadth of GeoSCOPE faculty spe-
cializations. The program also brings lo-
EPO Spotlight: Rosemary Hickey-Vargas,
Principal Investigator of GeoSCOPE
Paul Wyer interviewed Dr. Rosemary Hickey-Vargas, Florida International University
partment Chair that she and other faculty
pooled their experiences with FIU stu-
dents, and assembled an ambitious NSF-
OEDG (Opportunities for Enhancing
Diversity in the Geosciences) proposal
for “GeoSCOPE” (Geo Science Career
OPportunity Exploration). Funded in
2003 for three years, the project currently
involves eight department faculty, with
Rosemary as Principal Investigator. The
other faculty are co-PI Grenville Draper
and co-investigators BillAnderson, Lau-
Two GeoScope interns melt rocks for entertainment, science, experience, and a living
EPO Spotlight

cal high school science teachers in for a
summer workshop that engages them in
exciting, cutting edge research that they
can take back to their classes.
A dedicated website acts as an online
resource for those interested in learning
more about the program, internships and
teacher workshops: www.fiu.edu/orgs/
geology/template2/geoscope/
At a time when minority students can
still choose to pursue a major or gradu-
ate geoscience degree, GeoSCOPE raises
their awareness of the opportunities that
the subject offers. There is certainly no
shortage of interested students at FIU,
where the undergraduate community is
roughly 52% Hispanic, 21% white/non-
Hispanic, 15% African-American, 3%
Asian, and 1% Native American. The
demography of Miami-Dade County,
where FIU is situated, is similar, ensur-
ing a comparable impact for outreach
aimed at local high school teachers.
As is essential for any such project,
the success of GeoSCOPE is bench-
marked in a systematic way, in this case
via carefully structured questionnaires
returned by the student participants at the
end of their internships. From the feed-
back received thus far, Rosemary and her
collaborators appear to be making a tan-
gible impact, with most students enjoy-
ing the experience and stating that it has
improved their understanding of geo-
science and likelihood of pursuing a sci-
entific career. Notably, one intern went
on to get a McNair Fellowship for
paleobiological research, and another
now has a Florida Georgia LSAMP
(Louis Stokes Alliances for Minority
Participation) Fellowship in physics.
At two years in, a GeoSCOPE-driven
path from internship to geoscience ma-
jor is not yet evident, but may become
clearer as students encounter contempo-
rary pressures on other science majors,
or at the graduate level. About 10% of
GeoSCOPE interns to date have either
become geoscience majors or intend to
apply to geoscience graduate programs
after completing other science degrees.
Even for those who don’t go on to a geo-
science career, the program provides
them with paid research that broadens
their experience and supports their
completion of college.
At FIU, the graduate students also
benefit from their work alongside
GeoSCOPE interns, especially when the
interns bring in mutually beneficial com-
puter, math or other technical skills. As
for the participating faculty, the program
allows them to work and interact with
undergraduates at a research level, po-
tentially furthering their own research
goals in the process.
By way of example, Rosemary’s own
Subduction Factory research has directly
benefited from the program. In support
of her MARGINS-funded research on the
Izu-Bonin-Marianas Arc, two under-
graduate majors and two interns collec-
tively processed glass and mineral shards
from a volcaniclastic sediment sequence,
and were able to present their results at
the Spring 2005 AGU Joint Assembly.
Her most recent interns worked along-
side two graduate students, igniting and
fusing rock powders (they greatly en-
joyed informing their peers about “melt-
ing rocks for a living!”), and running
major element analyses in support of an
NSF-EAR funded project.
From a personal perspective, how-
ever, Rosemary finds the greatest rewards
are her interactions with interns and
teachers, especially at that moment of
understanding when the meaning and
scope of what “geoscience” can be sud-
denly become clear.
Asked what aspects of running
GeoSCOPE are harder or easier than
originally expected, Rosemary’s first re-
sponse is that the enthusiasm of the in-
terns goes a long way, and is part of what
makes the program such a rewarding ex-
perience. By contrast, the most difficult
aspect has been the administrative over-
head that comes with recruitment, regis-
tration, finances and symposia for around
twenty interns and the high school teach-
ers the project serves. Rosemary suggests
that budgeting for a non-scientist coor-
dinator from the start would have been a
good way to take these burdens away
from the participating scientists.
From Rosemary’s viewpoint, the key
to obtaining support and making a suc-
cess of an education or outreach program
is to demonstrate that it will make an
impact on the target group (K-12, teach-
ers, general public, etc.) in a way that
complements the research activities of the
proponents. That way, proponents guar-
antee not only to NSF that they have the
expertise needed to guide the participant
activities, but also to themselves that the
project will have a facet that they will
especially enjoy. Rosemary notes that any
NSF proposal submission can benefit by
including specific elements addressed
through education or public outreach, and
that activities can also be appended to
existing proposals through the NSF-REU
(Research Experiences for Undergradu-
ates) program.
In meeting and communicating with
Rosemary by e-mail, what really comes
through is her enthusiasm and imagina-
tion when it comes to opportunities for
maximizing the benefits of outreach. The
expertise and energy she brings to the
MARGINS Education and Public Out-
reach Committee are greatly appreciated
by the MARGINS Chair, Steering Com-
mittee and Office. With the input that she
and the rest of the EPO Committee pro-
vide, and a proposal for a community
workshop on the subject in preparation,
we look forward to development of a
structured plan for education and out-
reach objectives across the breadth of the
MARGINS Program. We expect Rose-
mary to be a key contributor along the
way.
There are many ways to obtain fund-
ing from NSF for undergraduate re-
search: GeoSCOPE’s funding came
from a natural synthesis with OEDG
(Opportunities for Enhancing Diver-
sity in the Geosciences), which is, “de-
signed to address the fact that certain
groups are underrepresented in the
geosciences relative to the proportions
of those groups in the general popula-
tion.” GeoSCOPE has benefited
greatly from advice provided by the
sponsoring OEDG Program Officers:
Dr. Jewel Prendeville initially, and lat-
terly Dr. Jacqueline Huntoon.
EPO Spotlight

MARGINS Newsletter No. 15, Fall 2005 AGU 2005
Sessions Related to MARGINS Science
at the Fall 2005 AGU Meeting
The diversity and range of MARGINS research and goals make it increasingly difficult to select a shortlist that captures all AGU
sessions of special interest to the MARGINS community. However, comments from last year suggest that - although not comprehen-
sive - the list and brief summaries (derived from the full abstracts on the AGU website: www.agu.org/meetings/fm05/) can be a handy
guide to have at the meeting.
AGU Code Key: Section: Day of Week (1-5): Session Time (1X-2X: 08:00 and 10:20; 3X-4X: 13:40 and 16:00). E.g., T11E =
Tectonics, Monday, Session 1E (13:40). Please refer to the AGU meeting program to verify session times and locations.
MARGINS Sessions
T: Fluids at subduction zones: Integrating
models and observations within MAR-
GINS and related studies
Pore fluids and fluid flow play defining roles
in subduction zone processes, over a wide
range of depths and scales. Such processes
include rock diagenesis and alteration, fault
zone stability and seismogenesis, upper and
lower plate deformation, dehydration reac-
tion in downgoing crust and mantle, magma
formation and migration, dynamics of the
mantle wedge, and earthquake nucleation.
For this reason, characterizing the occurrence
and role of fluids at subduction zones has
been a key component of both the
Seismogenic Zone Experiments (SEIZE) and
Subduction Factory (SubFac) Initiative of the
NSF MARGINS Program. Unfortunately,
direct observations of fluids and fluid pro-
cesses have been limited. Further progress
in understanding the role of fluids can be
gained from integrated fluid flow, thermal,
chemical, and deformational modeling, cali-
brated by observations and measurements of
subduction zone processes and properties.
This session is intended to bring numerical
modelers together with those who collect and
interpret geophysical, geodetic, seafloor, and
drilling data relevant to subduction zone flu-
ids. T11E, T12B (MCC 3011), T13B (MCC
Level 1, 0453-0481).
T: Izu-Bonin-Mariana Subduction Factory
studies
The Izu-Bonin-Mariana (IBM) system is per-
haps the best-studied example of an intra-
oceanic arc and a primary focus region for
subduction factory studies in the MARGINS
programs of several countries. Recently ma-
jor advances have been made in understand-
ing the geological history and geochemical
cycling of the IBM system, and revealing the
crust and mantle structure of the IBM arc and
backarc. These results have important impli-
cations for understanding subduction zone
dynamics, mantle flow and magma produc-
tion in arcs and backarcs, and the formation
of arc crust. This session will be comprised
of papers on IBM subduction zone studies,
including the formation of arc magma and
crust, studies of the geological history or cur-
rent tectonics of the arc, constraints on geo-
physical structure and mantle flow, and mod-
eling studies with implications for the IBM
system. T44A (MCC 3024), T53A (MCC
Level 2, 1393-1416)
Sessions relevant to
MARGINS science
ED: Integrating education and outreach
with large-scale experiments
Large-scale, long-term experiments, such as
EarthScope, Cassini, and IODP, frequently
capture the public’s imagination, providing
unique education and outreach opportunities.
This session focuses on such efforts and the
special issues inherent to large scale experi-
ments, with emphasis on developing and
maintaining high levels of public interest and
interaction. ED11E (MCC Level 2, 1126-
1131), ED14A (MCC 3007)
ED: Research Experiences for Under-
graduates (REU) at 25: Its impact on un-
dergraduate education in the sciences
In recognition of 25 years of the National
Science Foundation-Research Experiences
for Undergraduates (NSF-REU) Program,
this session will highlight REU initiatives,
examine best practices for research with un-
dergraduates in different scientific disci-
plines, and assess the role of REU in
Bachelor’s degree programs today. ED31A
(MCC Level 2, 1195-1203), ED41A (MCC
3009)
ED: Undergraduate research in the earth
and environmental sciences: shaping the
cutting edge of our discipline
This session will explore the role of under-
graduate research in establishing the future
direction of the Earth and Environmental
Sciences. Contributors will showcase ex-
amples of the diverse research projects in
which undergraduate students are involved.
ED31B (MCC Level 2, 1204-1214), ED41B
(MCC 3009)
G: Aseismic deformation transients and
their relationship to earthquakes
Transient deformation is often detected after
moderate or large earthquakes nearby, and
includes triggered slip on other faults,
afterslip on or near the co-seismic rupture,
and viscous and poroelastic deformation in
the lower or upper lithosphere, or it can be
associated with other static or dynamic stress
changes. Much of this deformation is
aseismic or seismically small, but non-seis-
mic measurements and modeling of causes
and effects can provide information on the
material properties of fault zones and adja-
cent lithosphere. G43A, G44A (MCC 3005),
G51B (MCC Level 2, 0811-0836)
H: Beyond steady state: The dynamics of
transient landscapes
The last decade has witnessed significant
progress in understanding the linkages among
climate, surface processes, and tectonics.
Contributions to this session pertain to the
transient evolution of landscapes at all scales,
from hillslope to orogen, and how transient
conditions influence interpretation of data.
H31A (MCC Level 2, 1261-1288), H33F,
H34A (MCC 3000)
H: Impacts of hydrology on landscape evo-
lution
Hydrologic processes play important roles in
many aspects of long-term landscape evolu-
tion, but also depend on the landscape mor-
phology, introducing a feedback mechanism
in the system. This session explores links
between climatology, basin hydrology, and
long-term landscape evolution via theoreti-
cal, observational, and experimental contri-

butions. H42B (MCC 3002), H43D (MCC
Level 1, 0516-0530)
H: Constructional landscapes: From del-
tas to leveed channels
Channels that build their own banks are the
dominant conduits for water and sediment
transport in many subaerial and subaqueous
landscapes from lakes to the deep-marine
continental slope. This session shares ad-
vances in understanding the initiation and
growth of leveed channels and deltas, as well
as the landforms they construct, based on
field, laboratory or numerical studies across
multiple disciplines. H44D (MCC 3011),
H51D (MCC Level 1, 0393-0404)
H: Coupling sediment transport and chan-
nel morphology
Much remains to be learned about how flow
and sediment transport interact to produce the
morphology of natural channels. Contribu-
tions relate sediment transport to the stream
morphology across a range of scales, includ-
ing studies linking field or laboratory based
measurements of sediment transport to chan-
nel adjustment processes. H51H, H52A
(MCC 3000), H53B (MCC Level 1, 0455-
0476)
H: The hydrogeomorphic interface: Tem-
poral and spatial scales of interaction be-
tween hydrology and geomorphology
Hydrology, geomorphology and aspects of
riverine ecology strongly interact within the
context of a stream channel network. High-
lights of this session include: 1) interaction
between a changing hydrologic regime, sedi-
ment supply and/or stability of channel mor-
phology; 2) interaction between stream flow
regulation, riparian vegetation and channel
dynamics; and 3) temporal and spatial varia-
tion of channel forming flows in drainage
networks. H41I (MCC 3003), H43C (MCC
Level 1, 0506-0515)
H: Quantitative studies of the sources, fate,
and transport of dissolved and suspended
materials in streams
Rivers and streams are conduits for naturally
derived solutes and anthropogenically-pro-
duced contaminants in dissolved and particu-
late forms. Topics include: 1) weathering,
erosion and denudation, and riverine trans-
port of particulate and dissolved materials;
2) quantitatively identifying or budgeting
sediment sources; 3) novel statistical meth-
ods to estimate contaminant loads from in-
termittent concentrations data and continu-
ous stream flow data. H42B (MCC 3000),
H31D (MCC Level 2, 1325-1341)
IN: Building a global geoscience
cyberinfrastructure: International col-
laboration in geoinformatics
The emerging cyberinfrastructure for geo-
science must be an international effort in or-
der to successfully promote advances in geo-
science research and enable new approaches
to addressing scientific problems that in turn
lead to new discoveries and an improved
understanding of the Earth. This sessions fo-
cuses on collaboration and integration of in-
ternational digital data, information, analy-
sis and visualization tools. IN43C, IN44A
(MCC 3018), IN51A (MCC Level 1, 0305-
0316)
S: Fault-zone properties and earthquake
rupture dynamics
Recent studies show that fault zone materi-
als, fault structures, and stresses applied to
the fault significantly affect earthquake rup-
ture dynamics and near-fault ground motions.
Contributions include integration of seismic
reflection profiles, drilling of active fault
zones, in-situ measurements in boreholes, and
structural and microstructural studies that
define the prevailing deformation processes
affecting the faulting process. S31B, S32B,
S33C, S34A (MCC 3020), S41B, S43A
(MCC Level 2, 0977-1002, 1039-1068)
T: Subduction-zone paleoseismology on
the Pacific Rim
A forum on long records of great earthquakes
at Pacific Rim subduction zones, including
earthquake sizes and recurrence intervals,
comparisons with the ‘04 and ‘05 Sumatran
earthquakes, and applications to seismology,
geodesy, engineering, and tsunami simula-
tion. T11A (MCC Level 1, 0346-0362)
T: Static and dynamic strengths of faults:
Merging field, laboratory and numerical
approaches
The nature of slip on active faults is strongly
controlled by shear resistance which depends
on factors such as accumulated slip, rough-
ness, presence of fluids, temperature, pres-
sure and transport properties. This session
examines relationships between specific
micromechanical processes as observed in the
laboratory, field and imaged in
micromechanical models, and their macro-
scopic mechanical response. T13E, T14B
(MCC 3011), T21B (MCC Level 1, 0460-
0487)
T: Dynamics, structure, and composition
of subduction zones
Understanding the interplay between dynam-
ics, structure and composition is crucial to
developing a comprehensive model of the
shallow portions of the subduction zone sys-
tem. This session focuses on research into
the critical parameters affecting subduction
zone creation, evolution and behavior, includ-
ing observations and modeling in novel
multidisciplinary studies. T31D (MCC
3011), T33B, T33C (MCC Level 1, 0528-
0582), T41F, T42A (MCC 3011)
T: Comprehensive testable predictions of
geodynamic models
Recent advanced geodynamic models oper-
ate with large number of parameters whose
adjustment may allow fitting of geological
and geophysical constraints, but do not nec-
essarily prove their validity. The aim of this
session is to attract attention of the
geodynamic modelers to the importance of
verification and testing of their models and
to involve geologists and geophysicists in
discussion of how to accomplish this. T12A,
T13F, T14A (MCC 3024), T21C (MCC
Level 1, 0488-0521)
T: Extensional tectonics and metamorphic
core complexes: Their metamorphic, pet-
rographic, and kinematic evolution
Within the last quarter century, our under-
standing of continental extensional tectonics
and associated metamorphic core complexes
has improved substantially, but there are still
many important questions and debates. As a
catalyst for new research, this session brings
together researchers working on these prob-
lems in the well studied extensional terranes
of the Basins and Ranges of western North
America and theAegean region of southeast-
ern Europe. T13C (MCC Level 1, 0482-
0493), T24C (MCC 3022)
T: Mechanisms of continental extension
during basin and rifted-margin formation
The mechanisms by which continental
crust thins from >30 km to <6 km prior to
break-up are not well understood, and there
is no consensus on the rheological behav-
ior of the lower crust during extension.This
session considers observational data and
numerical models that give insights into
processes such as fault array evolution and

strain localization, strain partitioning with
depth, evolving rift (a)symmetry, and con-
jugate margin subsidence patterns. T43B
(MCC Level 2, 1389-1415), T51E, T52B,
T53E (MCC 3011)
V: Will the real phenocryst please stand
up?
Fractional crystallization is the dominant
process promoting magma differentiation,
but many erupted magmas contain solid
phases that are complexly zoned and/or de-
monstrably out of equilibrium with their
host melts. This session addresses the im-
portant challenge of converting the infor-
mation carried by magma’s ‘crystal cargo’
into process-related and component-spe-
cific constraints on magma evolution.
V11A, V12A (MCC 3007), V13B (MCC
Level 1, 0523-0557)
V: The agent of mass transfer in subduc-
tion zones: Fluid, melt, or supercritical?
Thermal and chemical exchange between
subducting oceanic lithosphere and the
overlying mantle wedge at convergent
margins produces what is arguably the most
physically and compositionally complex
melting regime in the upper mantle. This
session brings together evidence bearing on
the physical and chemical nature of the sub-
duction component and the mass transfer
process in subduction zones. V31C (MCC
Level 1, 0618-0641), V33C, V34A(MCC
3009)
V: From the mantle to the surface and
back again: Deep storage, degassing, and
subduction of terrestrial volatiles
This session examines terrestrial volatiles
in the Earth’s interior, including their char-
acteristics in different mantle phases/res-
ervoirs, their role during melting, and their
cycling to/from the exosphere.
Multidisciplinary contributions encompass
all aspects of deep Earth volatile cycles.
V41A (MCC Level 2, 1416-1437), V51F,
V52A, V53F (MCC 3009)
V: Development and evolution of
intraoceanic arc crust: The record from
crustal sections and xenoliths
The goal of this session is to bring together
studies of well-exposed arc crustal sections
to gain a better understanding of the growth
and evolution of intraoceanic arcs and the
development of continental crust. The ses-
sion also includes abstracts on continental
arc lower crust and xenolith studies from
modern arc settings. V44C (MCC 3007),
V51D (MCC Level 2, 1513-1526)
V: Temperature, chemistry, and dynam-
ics of the mantle
To provide stronger constraints on mantle
convection, volcanism, and plate tectonics,
an improved understanding of the major el-
ement, trace element, isotopic, and thermal
structure of the mantle is required. This in-
terdisciplinary session will address all as-
pects of the variations of temperature and
chemistry of the mantle and their implica-
tions for mantle dynamics and the conten-
tious debate on mantle plumes. V31F,
V32B, V33D (MCC 3007), V41C (MCC
Level 2, 1453-1473), V41E (MCC Level
2, 1503-1522), V43E (MCC 3007)
Other sessions of interest
G: Plate Boundary Observatory and
Crustal Deformation. G21B (MCC Level
2, 1263-1284)
GP: New insights into Earth’s properties
and processes from electrical conductivity
studies. GP34A (MCC 3008), GP41B
(MCC Level 2, 0867-0882)
H: Exploring the response of high-latitude
landscapes and processes to global change.
H51G (MCC Level 1, 0440-0450), H53I
(MCC 2002)
IN: Emerging better, or best, practices for
Distributed Data Systems and Virtual Ob-
servatories. IN23C, IN24A (Marriott Sa-
lon 10), IN31B (MCC Level 2, 1143-1159)
IN: Data fusion. IN31A (MCC Level 2,
1137-1142)
OS: Sedimentation, overpressure, and
slope stability along deepwater continen-
tal margins. OS21A(MCC Level 2, 1505-
1522), OS24A (MCC 2010)
S: Earthquake hazards forecasting: Real-
ity, potential, and applications. S42B,
S43D, S44B (MCC 3020), S51D, S53B
(MCC Level 2, 1027-1048, 1092-1110)
S: The earthquake source. S11C, S12A
(MCC 3022), S13B (MCC Level 1, 0188-
0209)
S: Earthquakes, active sources and tecton-
ics. S21C, S22A (Marriott Salon 3), S23B
(MCC Level 1, 0232-0263)
S: Fault-zone properties and earthquake
rupture dynamics. S31B, S32B, S33C,
S34A (MCC 3020), S41B, S43A (MCC
Level 2, 0977-1002, 1039-1068)
T: Links between ophiolites and the lost
large igneous provinces record. T11C
(MCC Level 1, 039-0403), T21E
(Marriott Salon 5)
T: Crustal construction, tectonic, alteration,
microbiological, and transport processes on
the flanks of mid-ocean ridges. T23F
(MCC 3022), T33A, T33D (MCC Level
1, 0509-0527, 0583-0597)
T: Geothermal systems: Fantastic natural
laboratories and a valuable energy resource.
T22A (Marriott Salon 5), T23B (MCC
Level 1, 0538-0562)
T: Continental margins: Geodynamic con-
straints and implications for the legal con-
tinental shelf under UNCLOS. T21C
(Marriott Salon 5), T13D (MCC Level
1, 0494-0510)
U: Interdisciplinary studies of the 26 De-
cember 2004 Great Sumatra-Andaman
Earthquake and Tsunami. U11A, U11B
(MCC Level 2, 0801-0842), U13A, U14A,
U21C, U22A (Marriott Salon 7)
U: Frontiers of geophysics lecture: The
2004 Sumatra mega earthquake: Lessons
from a monster. U22B (13:00, Marriott
Salon 9)
U: Beyond plate tectonics. U43B (MCC
Level 2, 0828-0837), U51B, U52A, U53A
(MCC 3001)
V: Massive collapse of volcanoes in island
arcs and continental volcanic arcs: Struc-
ture, mechanics, and implications of insta-
bility. V13F (Marriott Salon 10), V21B
(MCC Level 1, 0598-0607)
V: Seamount hydrothermal systems: Vol-
canology, biology, geochemistry and
oceanography. V44A(MCC 3009), V51C
(MCC Level 2, 1489-1512)
AGU 2005

Time: 6 - 8 pm
Date: Tuesday, 6 December, 2005
Location: San Francisco Marriott, across from the Moscone Center
Room: Golden Gate B2
MARGINS will be hosting a “Lecture and Reception” at this year’s AGU Fall Meeting. This event includes two
invited lectures from esteemed scientists conducting MARGINS research. Their presentations will be targeted at a
broad scientific audience, and will highlight recent advances in the MARGINS Subduction Factory and Source-to-
Sink Initiatives.
Prof. Charles Nittrouer is a Professor of Earth and Space Sciences and Coordinator of Strata FORmation on Mar-
gins (STRATAFORM). His MARGINS research focuses on sediment transport and accumulation in relation to
clinoform development at continental margins. He is extremely active in the Source to Sink community, having
coordinated one of the Science Plan workshops and served on the MARGINS Steering Committee.
Prof. Douglas Wiens is a Professor in the Department of Earth and Planetary Sciences at Washington University in
St. Louis. Amongst his many roles in scientific research and planning, he is a member of National Academy Inter-
national Polar Year Planning Committee, and has served on several committees for Incorporated Research Institu-
tions in Seismology (IRIS) and on the Steering Committees for RIDGE2000 and MARGINS.
Both speakers have extensive field and cruise experience as chief scientists and as scientific party members.
margins.wustl.edu agu.org
MARGINS Lecture and Reception
AGU Fall Meeting 2005
The lectures will be followed by updates on MARGINS funding and other issues from NSF Program Officer Bilal
Haq, and MARGINS Chair Julie Morris.
Washington University in St. Louis, current host of the MARGINS Office and Chair, is co-sponsoring the Recep-
tion, which will include ample time for mingling, questions and discussion. Refreshments and light food will be
provided.
Lectures:
The Ties that Bind Source to Sink, within and between New Guinea and New Zealand
Dr. Charles A. Nittrouer, University of Washington, School of Oceanography.
Geophysical Imaging of the Mantle Wedge: Temperature, Melt, Fluids, and Mantle Flow
Dr. Douglas A. Wiens, Washington University in St. Louis, Department of Earth and
Planetary Sciences.

ADVERTISEMENT
The Seismogenic Zone of Subduction Thrust Faults
MARGINS Theoretical and Experimental Earth Science Series, Volume 2
Columbia University Press, 2006.
Table of Contents
• Timothy H. Dixon and J. Casey Moore, The Seismogenic
Zone of Subduction Thrust Faults: Introduction
• Roy D. Hyndman, The Seismogenic Zone of Subduction
Thrust Faults: What We Know and What We Don’t Know
The Incoming Plate
• Michael B. Underwood, Sediment Inputs to Subduction
Zones: Why Lithostratigraphy and Clay Mineralogy Matter
• M. Hutnak, A. T. Fisher, C. A. Stein R. Harris, K. Wang, E.
Silver, G. Spinelli M. Pfender, H. Villinger, R. Macknight, P.
Costa Pisani, H. DeShon, and C. Diamente, The Thermal
State of 18-24 Ma Upper Lithosphere Subducting Below the
Nicoya Peninsula, Northern Costa Rica Margin
• Susan L. Bilek, Influence of Subducting Topography on
Earthquake Rupture
Convergent Margin Structure, Fluids and
Subduction Thrust Evolution
• Barbara A. Bekins and Elizabeth J. Screaton, Pore Pressure
and Fluid Flow in the Northern Barbados Accretionary
Complex: a Synthesis
• Demian Saffer, Pore Pressure Within Underthrust Sediments
in Subduction Zones
• Julia K. Morgan, Elizabeth B. Sunderland, and Maria V. S.
Ask, Deformation and Diagenesis at the Nankai Subduction
Zone: Implications for Sediment Mechanics, Decollement
Initiation and Propagation
• Kirk D. Mcintosh, Eli A. Silver, Imtiaz Ahmed, Arnim
Berhorst, Cesar R. Ranero, Robyn K. Kelly, and Ernst R.
Flueh, The Nicaragua Convergent Margin: Seismic Reflec-
tion Imaging of the Source of a Tsunami Earthquake
• J. Casey Moore, Christie Rowe, and Francesca Meneghini,
How Accretionary Prisms Elucidate Seismogenesis in
Subduction Zones
Laboratory Studies
• Chris Marone and Demian Saffer, Fault Friction and the
Upper Transition From Seismic to Aseismic Faulting
• N.M. Beeler, Laboratory-observed Faulting in Intrinsically
and Apparently Weak Materials: Strength, Seismic Coupling,
Dilatancy and Pore Fluid Pressure
• Diane E. Moore and David A. Lockner, Friction of the
Smectite Clay Montmorillonite: a Review and Interpretation
of Data
Seismic and Geodetic Studies
• Akira Hasegawa, Naoki Uchida, Toshihiro Igarashi, Toru
Matsuzawa, Tomomi Okada, Satoshi Miura, and Yoko Suwa,
Asperities and Quasi-static Slip on the Subducting Plate
Boundary East off Tohoko, Northeast Japan
• Thorne Lay and Susan Bilek, Anomalous Earthquake
Ruptures at Shallow Depths on Subduction Zone
Megathrusts
• Kosuke Heki, Secular, Transient and Seasonal Crustal
Movements in Japan From a Dense GPS Array: Implication
for Plate Dynamics in Convergent Boundaries
• Kelin Wang, Elastic and Viscoelastic Models of Crustal
Deformation in Subduction Earthquake Cycles
• Susan Y. Schwartz and Heather R. DeShon, Distinct Up-dip
Limits to Geodetic Locking and Microseismicity at the
Northern Costa Rica Seismogenic Zone: Evidence for Two
Mechanical Transitions.
Regional Scale Deformation
• Tetsuzo Seno, Collision Versus Subduction: the Importance
of Slab Dehydration
• Jonas Kley and Tim Vietor, Subduction and Mountain
Building in the Central Andes.
• Inside the Subduction Factory
www.agu.org/cgi-bin/agubookstore?book=SEGM1389973&search=subduction%20factory
• Rheology and Deformation of the Lithosphere at Continental Margins
www.columbia.edu/cu/cup/catalog/data/023112/0231127383.HTM
Additional MARGINS Volumes Currently Available
Order through the web addresses given, or additional information may be found at www.margins.wustl.edu/Books.html

“SF” cont. from Page 5
structures, large-offset crustal imaging of
the entire arc and backarc crust, and pas-
sive (earthquake) imaging of the mantle
beneath arc and backarc. Data collection
was completed by mid-2004 when Ocean
Bottom Seismometers were recovered;
active-source data were collected over the
three prior years. Initial findings have
been presented at a workshop in Japan
in June, 2005, attended by all project sci-
entists. Initial results from the earthquake
experiment have shown significant
anisotropy beneath the arc and the pres-
ence of a double seismic zone. They also
show that thrust zone earthquakes are
absent in the vicinity of forearc
serpentinite mud volcanoes, thought to
be the surface expression of extensive
hydration of the shallow lithospheric
mantle of the upper plate. In December
2005, a magnetotelluric experiment will
be deployed along the same transect,
which should facilitate tests of hypoth-
eses regarding fluid pathways in the slab
and wedge. Many of the results will be
presented at a special session on the Izu-
Bonin-Mariana subduction factory at the
2005 FallAGU meeting and at the MAR-
GINS lecture and reception (see pp. 14
and 17, respectively).
The Central America geophysical
projects benefit from a synergy between
SEIZE and SubFac, particularly in the
characterization of the incoming plate
(see article, p. 1). The Cocos plate ap-
pears unusual in having quite low heat
flow associated with vigorous hydrother-
mal circulation (Fisher et al., 2003) and
deep bending-related faults that may
serve as significant conduits of fluids into
the subducting mantle (Ranero et al.,
2003). Results from ODP Leg 205 and
IODP Expedition 301T are showing vig-
orous fluid flow in the shallow igneous
section of the incoming plate. Work con-
tinues to characterize the incoming plate
and in particular to test the hypothesis of
massive serpentinization of its mantle.
The German GEOMAR group has plans
for a series of marine seismic experi-
ments in 2005-2006, and a large active
source US-led experiment will take place
when the new multi-channel ship be-
comes available.
Along the volcanic arc there are first-
order changes in lava chemistry between
Costa Rica and Nicaragua (Carr, 2003)
despite relatively weak differences in the
incoming plate (Peacock et al., 2005).
Hence, there should be significant differ-
ences in how the slab or mantle wedge
processes material bound for the arc. For
example, preliminary analysis of regional
wave propagation indicates that the slab
beneath Nicaragua may be unusually
hydrated by global standards (Abers et
al., 2003). The 48 station TUCAN broad-
band experiment, which will be in the
field until March 2006, provides the data
needed for imaging the downgoing plate
and arc mantle (Abers et al., 2004). The
passive seismic experiment is comple-
mented by an active-source crustal im-
aging experiment, transecting the arc in
Costa Rica and paralleling the TUCAN
along-strike transect. The terrestrial part
of this experiment was shot during 2 field
seasons in 2005 (Holbrook, Lizarralde et
al., PI’s), and will provide primary data
on the problems of crustal architecture
and growth rates. The off-shore compo-
nent is awaiting the refitting of the R/V
Langseth.
The future of the Subduc-
tion Factory Initiative
The maturity of the Subduction Fac-
tory Initiative is clearly shown in the
number of projects that have generated
publications over the past few years and
the breadth of ongoing research. Many
of the gaps in research identified in the
focus sites by the MARGINS commu-
nity and Steering Committee are being
covered. The 2004 MARGINS Review
Committee recognized this maturity and
indicated that the SubFac initiative would
benefit greatly by having an integrative
meeting. On the other hand, much of the
basic data collection (particularly the
geophysical efforts) are still ongoing, so
it may be a bit premature to reach clo-
sure on many aspects of the program.
Over the next few years, it is expected
that these studies will reach fruition while
synthesis and programmatic evaluation
takes place.
In order to facilitate such a synthesis,
the MARGINS Steering Committee in its
spring meeting this year suggested that
proposals should be solicited for a new
integrative TEI, nominally in 2007 (see
“From the MARGINS Chair”, Spring
2005 MARGINS Newsletter 14). Al-
though focus site work vigorously con-
tinues, it is not too early to begin
considering the future of SubFac. In par-
ticular, are there compelling reasons to
seek a renewed round of work in these
focus areas, with goals informed by ear-
lier successes, or would change to new
focus sites be something to consider, par-
ticularly to sites where cross-program
synergies may be attained (e.g.,
Earthscope, IODP, OOI)? At what point
should basic SubFac science goals be re-
evaluated in light of what has been
learned so far? Answers to these ques-
tions will require extensive community
involvement and will take some time. A
significant TEI would be a first step.
References
Abers, G. A., B. H. Hacker, and T. Plank
(2003) The wet Nicaragua slab, Geophys.
Res. Lett., 30, 1098.
Abers, G.A., L.Auger, E. Syracuse, T. Plank,
K.M. Fischer, C. Rychert, A. Walker, J.
Protti, V. Gonzalez Salas, W. Strauch, and
P. Perez (2004) Imaging the Subduction
Factory Beneath Central America: The
TUCAN Broadband Seismic Experiment,
EOS, 85, T21B-0524.
Bloomer, S.H., J. Kimura, R.J. Stern, Y.
Ohara, T. Ishii, O. Ishizuka, S. Haraguchi,
S. Machida, M. Reagan, K. Kelley, U.
Hargrove, M. Wortel, and Y.B. Li (2004)
Petrochemical Results for Volcanic Rocks
recovered from SHINKAI 6500 diving on
the Bonin Ridge (27°15’N-28°25’N):
submarine extension of Ogasawara
forearc volcanism, EOS, 85, V41B-1383.
Carr, M. J., M. D. Feigenson, and L. C. Patino
(2003), Volcanism and geochemistry in
CentralAmerica; Progress and Problems,
in Inside the Subduction Factory, Geo-
physical Monograph. 138, J. M. Eiler,
(ed) 153-174.
Chan, L.H., W.P. Leeman, C.F. You (2002)
Lithium isotopic composition of Central

American volcanic arc lavas; implications
for modification of subarc mantle by slab-
derived fluids; correction, Chemical Ge-
ology, 182, 293-300.
Connolly, J.A.D., and D.M. Kerrick (2002)
Metamorphic controls on seismic veloc-
ity of subducted oceanic crust at 100-250
km depth, Earth and Planetary Science
Letters, 204, 61-74.
de Moor, J.M., T.P. Fischer, D.R. Hilton, E.
Hauri, L.A. Jaffe and J.T. Camacho
(2005) Degassing at Anatahan volcano
during the May 2003 eruption: Implica-
tions from petrology, ash leachates, and
SO2 emissions, Journal of Volcanology
and Geothermal Research, 146, 117-138.
Eiler, J. (2003), editor, Inside the Subduction
Factory, Geophysical Monograph. 138, 1-
311.
Eiler J. M., M. J. Carr, M. Reagan, and E.
Stolper (2005) Oxygen isotope con-
straints on the sources of Central Ameri-
can arc lavas, Geochemistry, Geophysics,
Geosystems, 6, doi:10.1029/
2004GC000804.
Feigenson, M.D., M.J. Carr, S.V. Maharaj,
S. Juliano, and L.L. Bolge (2004) Lead
isotope composition of CentralAmerican
volcanoes: Influence of the Galapagos
plume, Geochemistry, Geophysics,
Geosystems, 5, doi:10.1029/
2003GC000621.
Fischer, T.P., Hilton, D.R., Shaw, A.M.,
Hauri, E.H., Kazahaya, K., Mitchell, E.,
Shimizu, A., de Moor, J.M. Sharp, Z.D.
(2005) Tracing slab inputs along the Izu-
Bonin-Marianas subduction zone: results
from volatile emissions.AGU Fall Meet-
ing Abstracts, 2005.
Fisher, A. T., C. A. Stein, R. N. Harris, K.
Wang, E. A. Silver, M. Pfender, M.
Hutnak,A. Cherkaoui, R. Bodzin, and H.
Villinger (2003)Abrupt thermal transition
reveals hydrothermal boundary and role
of seamounts within Cocos Plate, Geo-
physical Research Letters, 30, art. 150.
Grove, T.L., S.W. Parman, T. Plank, K.A.
Kelley, and T.W. Sisson (2004) Estimat-
ing Temperatures and Dissolved H2
O
Contents ofArcAndesite and Basalt Mag-
mas, EOS, 85, V12A-06.
Hall, C.E., M. Gurnis, M. Sdrolias, L.L.
Lavier, and R.D. Müller (2003) Cata-
strophic initiation of subduction follow-
ing forced convergence across fracture
zones, Earth and Planetary Science Let-
ters, 212, 15-30.
Hilton, D.R., J.S. Pallister, and R.M. Pua
(2005) editors, The 2003 Eruption of
Anatahan Volcano, Commonwealth of the
Northern Mariana Islands, Journal of
Volcanology and Geothermal Research,
146, 1-256.
Ishizuka, O., J-I. Kimura, Y.B. Li, R.J. Stern,
M. Reagan, R.N. Taylor, U. Hargrove, T.
Ishii, S. Haraguchi, Y. Ohara, and S.H.
Bloomer (2005) Geochemical character-
istics of the earliest volcanism in the Izu-
Bonin forearc, Geophysical Research
Abstracts, 7, 05972.
Kelley, K.A. and Plank, T. (2005) Distribu-
tion of water in the mantle wedge of sub-
duction zones, Goldschmidt Conference
Abstracts, 15, A632.
Kelley, K.A., T. Plank, S. Newman, E.
Stolper, T.L. Grove, and E. Hauri, Mantle
melting as a function of water content at
subduction zones. I: Back-arc Basins.
Journal of Geophysical Research, submit-
ted.
Kent, A.J.R. and J.B. Gill (2005) Volatile
(H2
O, CO2
, Cl, S) contents of magmas in
the Izu-Bonin back and rear arc, EOS
Kent, A.J.R., and Rowe M.C. (2004) Chlo-
rine cycling in subduction zones: insights
from submarine glasses and melt inclu-
sions from arc and back-arc basalts. EOS
Morris, J.D., W.P. Leeman, and Tera, F.
(1990) The subducted component in is-
land arc lavas; constraints from B-Be iso-
topes and Be systematics. Nature, 344,
31-36.
Mottl, M.J; C.G. Wheat, P. Fryer, J. Gharib,
and J.B. Martin (2004) Chemistry of
springs across the Mariana forearc shows
progressive devolatilization of the sub-
ducting plate, Geochimica et
Cosmochimica Acta, 68, 4915-4933.
Peacock, S.M., P.E. van Keken, S.D.
Holloway, B.R. Hacker, G.A. Abers, and
R.L. Fergason (2005) Thermal structure
of the Costa Rica – Nicaragua subduc-
tion zone, Physics of The Earth and Plan-
etary Interiors, 149, 187-200.
Plank, T.,V. Balzer, and M. Carr (2002) Nica-
raguan volcanoes record paleoceano-
graphic changes accompanying closure of
the Panama gateway. Geology, 30, 1087–
1090.
Pozgay, S.H., R.A. White, D.A. Wiens, P.J.
Shore, A.W. Sauter, and J.L. Kaipat
(2005) Seismicity and tilt associated with
the 2003 Anatahan eruption sequence,
Journal of Volcanology and Geothermal
Research, 146, 60-76.
Ranero, C., J. Morgan, K. McIntosh, and C.
Reichert (2003) Bending-related faulting
and mantle serpentinization at the Middle
America trench, Nature, 425, 367-373.
Reagan, M., D. Mohler, B. Hanan, R. Hickey-
Vargas, and J. Blichert-Toft (2003)
Sources and melting processes for the
proto-Mariana arc. EUG-AGU-EGS joint
meeting, EAE03-A-14493.
Reagan, M., F.J. Tepley III, J.B. Gill,
M.Wortel, and B. Hartman (2005) Rapid
time scales of basalt to andesite differen-
tiation at Anatahan volcano, Mariana Is-
lands, Journal of Volcanology and Geo-
thermal Research, 146, 171-183.
Shaw, A.M., E. Hauri, K. Kelley, T. Fischer,
D. Hilton, R. Stern, J. Hawkins, and T.
Plank (2005) Hydrogen isotope variations
in Mariana Arc melt inclusions,
Goldschmidt Conference Abstracts, 15,
A631.
Shaw, A.M., D.R. Hilton, T.P. Fischer, J.A.
Walker, and G.E. Alvarado (2003) Con-
trasting He–C relationships in Nicaragua
and Costa Rica: insights into C cycling
through subduction zones, Earth and
Planetary Science Letters, 214, 499-513.
Stern, R.J. (2004) Subduction initiation:
spontaneous and induced, Earth and
Planetary Science Letters, Volume 226,
275-292.
Thomas, R.B., M.M. Hirschmann, H. Cheng,
M.K. Reagan, and R.L. Edwards (2002)
(231Pa/235U)-(230Th/238U) of young
mafic volcanic rocks from Nicaragua and
Costa Rica and the influence of flux melt-
ing on U-series systematics of arc lavas,
Geochimica et Cosmochimica Acta, 66,
4287-4309.
Wade, J.A., T. Plank, R.J. Stern, D.L.
Tollstrup, J.B. Gill, J.C. O’Leary, J.M.
Eiler, R.B. Moore, J.D. Woodhead, F.
Trusdell et al. (2005)The May 2003 erup-
tion of Anatahan volcano, Mariana Is-
lands: Geochemical evolution of a silicic
island-arc volcano, Journal of Volcanol-
ogy and Geothermal Research, 146, 139-
170.
Wiens, D. A., S. H. Pozgay, P. J. Shore, A.
W. Sauter, and R. A. White (2005), Tilt
recorded by a portable broadband seis-
mograph: The 2003 eruption ofAnatahan
Volcano, Mariana Islands, Geophysical
Research Letters, 32, art. no. L18305.
Zimmer, M.M, T. Fischer, D.R. Hilton, G.E.
Alvarado, Z.D. Sharp, and J.A. Walker
(2004) Nitrogen systematics and gas
fluxes of subduction zones; insights from
Costa Rica arc volatiles, Geochemistry,
Geophysics, Geosystems, 5, DOI 0.1029/
2003GC000651.

“Chair Report” cont. from Page 9
short steep rivers draining the York Pen-
insula; tectonic, climatic and ocean cir-
culation controls on clinoform construc-
tion; the distribution of clastic and car-
bonate sediments in the deep part of the
GoP; and the fate of terrestrial organic
carbon as it traverses the shallow shelf.
A recently funded project focuses atten-
tion on the tidally dominated delta of the
Fly River, from a modeling perspective.
Areas needing additional attention in-
clude sediment supply from the uplands
as a function of changing climate and
tectonics through time, including the
stratigraphic record archived in Lake
Murray and the sediment dispersal and
storage in the shallow (<20m) shelf. Re-
cent work has also highlighted the im-
portance of the ENSO record archived
offshore and the exemplar the region pro-
vides as a modern foreland basin. For
both focus areas, work on land (both
observational and theoretical) remains an
important need. Integration between
MARGINS S2S and the Community
Surface Dynamics Modeling System (see
page 10, this Newsletter) is a high pri-
ority.
MARGINS Distinguished
Lecturer Series
Response to the MARGINS lecture
series has been exceptional, and with a
large number of requests coming in each
containing an enthusiastic endorsement
of the scientific impact the speakers will
have on the hosting colleges and univer-
sities. For our inaugural year, speakers
are Neal Driscoll, Susan Schwartz, Joann
Stock and Terry Plank. Titles for their
technical and public lectures are shown
in the box below. Our thanks to all the
speakers for the time and energy they will
contribute, and congratulations on the ex-
cellent response they’ve generated. If you
would like to nominate speakers (includ-
ing yourself) for consideration for next
year’s distinguished lecturers, please
drop us a line.
MARGINS Education Plan-
ning
An ad hoc organizing committee for
a future workshop on educational initia-
tives to accompany MARGINS research
met at the MARGINS Office in mid-Oc-
tober. The group spent two days brain-
storming on a series of efforts that will
be the focus of an education and outreach
workshop to be held in mid-2006. Poten-
tial discussions at the workshop may in-
clude the development of undergraduate
research projects and mentorships, exten-
sions of the Distinguished Lecture Series
to include the production of DVDs for
widespread distribution to institutions,
and multimedia products for classroom
use that take advantage of the MARGINS
database, to name but a few.
MARGINS at AGU
If you look to p. 17 you’ll see that
we’re doing something a little different
this year atAGU. We’re very pleased that
AGU have allocated after-hours meeting
space for a “MARGINS Lecture and Re-
ception,” to be held at 6 pm on Tuesday,
December 6th, in the Marriott Golden
Gate Room B2. This event will offer two
MARGINS lectures of broad interest,
along with Program and funding news
from me and from our MARGINS Pro-
gram Officer, Dr. Bilal Haq. We are for-
tunate to have two widely renowned and
engaging speakers for the event, Chuck
Nittrouer and Doug Wiens have kindly
agreed to deliver lectures (see p. 17 for
details). If you’re at AGU, please join us
for what we expect to be a top notch
event! During AGU we will also be run-
ning the $1000 MARGINS Student Prize,
now in its third year. The MARGINS
Office (Paul and Meredith) and I will be
in and around the meeting all week, and
are always ready to listen to your com-
ments or questions. We look forward to
seeing you there.
Distinguished Lectureship Series - Technical and Public Lectures
(Dates and venues to be determined)
Neal Driscoll (Scripps Institution of Oceanography) - Source to Sink
Public Lecture: Reading Earth history from the geologic record
Technical Lecture: Dispersal systems in actively deforming regions: Papua New Guinea has it all!
Terry Plank (Boston University) - Subduction Factory
Public Lecture: Recycling within the Subduction Factory
Technical Lecture: The effect of water on mantle melting at subduction zones
Susan Schwartz (University of California, Santa Cruz) - Seismogenic Zone
Public Lecture: Great Earthquakes and Tsunamis: Causes and Effects
Technical Lecture: Seismic, Geodetic& Fluid Flow Constraints on Seismogenic Zone Procsses in Costa Rica
Joann Stock (California Institute of Technology) - Rupturing of Continental Lithosphere
Public Lecture: Plate tectonics and how continents split apart
Technical Lecture: Defining the continent/ocean boundary: Insights from active rifts
For more information on the MARGINS Distinguished Lectureship Program visit
www.margins.wustl.edu/DLProgram/

The October 2004 Mw=7.1 Nicaragua earthquake: Rupture process, aftershock locations, and the confluence of SEIZE and SubFac goals

The October 2004 Mw=7.1 Nicaragua earthquake: Rupture process, aftershock locations, and the confluence of SEIZE and SubFac goals

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to The October 2004 Mw=7.1 Nicaragua earthquake: Rupture process, aftershock locations, and the confluence of SEIZE and SubFac goals

Similar to The October 2004 Mw=7.1 Nicaragua earthquake: Rupture process, aftershock locations, and the confluence of SEIZE and SubFac goals (20)

Recently uploaded

Recently uploaded (20)

The October 2004 Mw=7.1 Nicaragua earthquake: Rupture process, aftershock locations, and the confluence of SEIZE and SubFac goals