2010.07. IPY conference, Oslo.

1. spatial analysis and modelling of periglacial processes
in Hurd Peninsula, Livingston Island (Antarctic Peninsula)
Lisbon, Portugal
Marco Jorge 1 , Gonçalo Vieira* 1, Miguel Ramos 2
1) CEG-IGOT - University of Lisbon , Portugal
2) Department of Physics, Universidad Alcalá de Henares, Spain
Introduction, aims Study Area
This work is the first attempt to model the spatial distribution of
periglacial processes in Hurd Peninsula. As so, at this point
methodologic issues are a major concern.
Both bivariate and multivariate statistical models were used to create
models of susceptibility to the ocurrence (in the space domain) of
solifluction lobes. The analysis was performed in the vicinity of the the
Juan Carlos I Spanish Antarctic Sation, where detailed topographic
information is available.
AIMS
Carachterize the spatial distribution of stone-banked solifluction
lobes; evaluate the environmental factors that control the spatial
distribution of the lobes; and use statistical models to assess the
susceptibility of the terrain to the the ocurrence of those geofeatures.
Methods
x1 x2 unique condition
layers / variables crossed with the dependent layer terrain units
geomorphologic map
(1:9)
x x
multivariate
weighting
SUSCEPTIBILITY MODELS
bivariate
weighting information value (Yin and Yan, 1988)
moraine ridge stone-banked solifluction lobes
till rock glacier
moraine, vulcanic
scree / talus slope
bedrock frost-shattered debris
logistic regression
seasonal lake fluvioglacial terrace
ephemeral stream
fluvioglacial fan
raised beach ridge
sandy sediments cobble beach
Results, discussion
BEST SUSCEPTIBILITY MODEL
Solifluction lobes are abundant and affect mainly frost-shattered
debris. These deposits derive from the older moraine material,
longer exposed to the frost weathering. Thus, their spatial
distribution relates closely to the pattern of deglaciation.
Both the Logistic regression model and the Information Value
model yeld very similar results, both on the success rate and on
the covariates that relate the most with the distribution of the
stone-banked solifluction lobes.
The statistical models of susceptibility to the ocurrence of stone-
lithology (surficial deposits) banked solifluction lobes show good results. Though, the quality of
slope these models is limited by the small dimension of the study area
aspect and by the fact that the activity of the lobes was not mapped
The next step is to make the modelling at the scale of the Hurd
SUSCEPTIBILITY MODEL WITHOUT
THE "BEST COVARIATE" (LITHOLOGY) Peninsula (c. 20 square km). New susceptibily models will be made
following the same methods and their prediction capabitilities will
be evaluated in areas not used to build the models.
Then, If climate surrogates appear as strong covariates, the
dimension "time" can be added to the modelling, so that
susceptibility maps can be derived for different climatic conditions.
Bibliography
Yin KL and Yan TZ (1988) Statistical prediction model for slope instability of
metamorphosed rocks. In: Landslides-Glissements de T errain. Proceedings V
International Symposium on Landslides, Vol. 2, Lausanne, Switzerland, pp
1269–1272