1. Graduate School
By: David Hoffmann

2. A Little About Myself
 Born and Raised on the Texas Gulf Coast
 Fishing and Boating on the Water

3. A Little About Myself
 Undergraduate Degree in Environmental Geoscience
 Oceanography Minor
 GIS Interest

4. A Little More About Myself
 SCUBA Instructor/Scientific Diver
 Use my degree to help map and preserve reefs

5. Introduction
 Qatar (well, almost)
 What is Multibeam Bathymetry
 Multibeaming on the RV Manta
 WGOM (Western Gulf of Mexico)
 RV Falkor
 Multibeam Raw Data
 CARIS & Processing
 Errors, Artifacts, & Editing
 Cleaned Data
 Geologic and Oceanographic Features

6. Qatar (well almost)
 Desert Country
 Oil and Gas are Major Industries
 Submarine Springs

7. What are submarine springs?
 Karst Environment
 Dissolution of soluble rock (carbonate, dolomite, gypsum)
 Conduit flow (focused fracture flow

8. Mapping Plan

9. What is Multibeam
Bathymetry
 Uses sound to produce images of the seafloor
 Speed of sound in seawater is ~1500 m/s
 2 way travel time

10. My First (and Last)
Oceanographic Cruise
 Multibeam Bathymetry Expedition
 RV Manta
 Coffee Lump Bank
 3 Day Sail
 Cruised at 5 knots
 Collected Seawater
 Saw some dolphins

11. Purpose of the Cruise
 Map Coffee Lump Bank
 Not a well-mapped feature
 Located in the Northwestern Gulf of Mexico on the continental shelf
 Valuable benthic habitat
 Potential addition within the Flower Garden Banks National Marine Sanctuary

12. RV Manta (NOAA)
 Homeport: Galveston, TX
 Aluminum Jet Catamaran
 Length: 25.2 m
 Beam: 9.14 m
 Cruising Speed: 27 knots
 Range: 623 Nautical Miles

13. Mapping Equipment
 Reson SeaBat 7125 multibeam sonar
 Frequency: 200 kHz
 Swath Coverage: 128o
 Number of Beams: 256

14. Raw Data

15. Processed Maps

16. Here Are Some Dolphins

17. Seawater Collection For
OCNG 252

18. Western Gulf of Mexico (WGOM)
Mapping
 50 to 100 miles East of the Southern coast of Texas
 Formed during the Younger Dryas about 10,000 years
ago
 14 Banks mapped
 2 Cruises
 RV Falkor

19. RV Falkor
 Home Port: Cayman Islands
 Length: 82.9 m
 Beam: 13.0 m
 Cruising Speed: 10 – 12 knots
 Range: 8000 Nautical Miles

20. Mapping Equipment
 Kongsberg EM 710
 Swath coverage of up to 3000 m
 70 to 100kHz
 128 beams

21. Processing Equipment
 CARIS
 HIPS and SIPS
 Comprehensive bathymetric, seafloor imagery, and water
column data processing software.
 Simultaneously process multibeam and backscatter data.

22. Previous vs Current Data
Big and Small Adam Banks

23. Previous vs Current Data
Dream Bank

24. Raw Data Examples
Dream Bank
Big and Small Adam
Banks

25. Artifact Errors: Beam Bounce

26. Artifact Errors: Holding
Station

27. Un-Cleaned vs Cleaned Data
Examples: Dream Bank

28. Un-Cleaned vs Cleaned Data
Examples: Dream Bank

29. Un-Cleaned vs Cleaned Data
Examples: Big and Small Adam
Banks

30. Un-Cleaned vs Cleaned Data
Examples: Steamer Bank

31. Moats Around the Banks

32. Moats on Man-Made Objects

33. Other Objects

34. Moat Characteristics

35. Sound Velocity
Thinks sound
velocity is faster
than it really is
Thinks sound
velocity is slower
than it really is
Sound velocity is
just right

36. Ewing Bank Example

37. Future Work and Analysis

38. References
 About Your Sancturary. 2015. National Ocean Service. Web. 7 December 2015.
 Davies, T.A., A.S. Laughton. “Sedimentary processes in the North Atlantic. In: Laughton, A.S., Berggren (Eds.),
Initial Reports of the Deep- Sea Drilling Project”, 12. US Gov. Printing Office, Washington, DC, 1972: pp. 905–
934.
 Flood, R. “Multibeam Mapping in Long Island Coastal Waters.” Long Island Geologists’ Abstracts Collection. 14
August 2010.
 Hewitt, A., R. Salisbury, J. Wilson. “Using Multibeam Echosounder Backscatter To Characterize Seafloor
Features.” Sea Technology Magazine (2010). Web. 7 December 2015.
 Howe, J.A. et al. “Seabed morphology and the bottom-current pathways around Rosemary Bank seamount,
northern Rockall Trough, North Atlantic.” Marine and Petrolem Geology (2006). 23: 165-181. Encyclopedia of
Coastal Science. pp 825-830. 2005.
 Inman, Douglas L. “Scour and Burial of Objects in Shallow Water.”
 “Multibeam Sonar Theory of Operation.” L-3 Communications SeaBeam Instruments. 141 Washington St, East
Walpole, MA.
 Nash, Harriet. “Trinational Governance to Protect Ecological Connectivity: Support for Establishing an
International Gulf of Mexico Marine Protected Area Network.” Texas A&M University, Corpus Christi. August
2013.
 Ritchie, K. B. and Brian D. Keller, eds. 2008. A Scientific Forum on the Gulf of Mexico: The Islands in the Stream
Concept. Marine Sanctuaries Conservation Series NMSP-08-04. U.S. Department of Commerce, National Oceanic
and Atmospheric Administration, National Marine Sanctuary Program, Silver Spring, MD. 105 pp.
 Roberts, D.G. “Sediment distribution around moated seamounts in the Rockall Trough.” Deep Sea Research
(1974). 21: 175-184.
 Stuart, Elaine. “What is Multibeam Backscatter?.” 2011. Web. 6 December 2015.

39. Acknowledgments
 Dr. Wes Tunnell from Texas A&M Corpus Christi and the
RV Falkor for providing the data.
 Dr. Troy Holcombe for providing knowledge and insight
into the data.
 CARIS tech support for being helpful and patient.
 This work is supported in part by NSF Grant Number
DUE1355807
 Dr. Niall Slowey for being patient and kind through all of
the ups and downs that have lead me to the completion
of my degree.
 My family and friends for the support to keep me
focused on my goals.