Regional and Nearshore Bathymetry of American Samoa: Implications for Tsunami Run-Up and Public Awareness

American Geophysical Union Fall Meeting
December 14-18, 2009, San Francisco, CA

Paper U21D-07 in Special Late-Breaking Session: The 2009 Samoan and Sumatran Earthquakes: Origins, Impacts and Consequences II

DJ Wright

Dept of Geosciences, Oregon State Univ

Corvallis, OR 97331-5506

dawn@dusk.geo.orst.edu

KR Hogrefe

USGS

Alaska Science Center

Anchorage, AK

D Naar

College of Marine Science

University of South Florida

Saint Petersburg, FL

J Roberts

Oregon Department of Geology and Mineral Industries

Portland, OR

JE Miller

Joint Institute for Marine and Atmospheric Research

University of Hawaii

Honolulu, HI

S Ferguson

NOAA Pacific Islands Fisheries Science Center

Coral Reef Ecosystem Division

Honolulu, HI

A Koppers

College of Oceanic and Atmospheric Sciences, Oregon State Univ

Corvallis, OR

T Battista

NOAA National Centers for Coastal Ocean Science

Center for Coastal Monitoring and Assessment

Silver Spring, MD

E Lim

Cooperative Institute for Research in Environmental Sciences

University of Colorado at Boulder

Boulder, CO

LA Taylor

NOAA National Geophysical Data Center

Boulder, CO

P Anderson

American Samoa Government, Coastal Mgmt Program

Pago Pago, American Samoa

We report on past compilations of deep and shallow-water multibeam bathymetry surveys, bathymetric derivations from high-resolution satellite imagery, and submersible dives conducted around Tutuila, American Samoa. Initial multibeam bathymetric surveys were conducted in 2001-2005 to support the Fagatele Bay National Marine Sanctuary, but subsequent data gathering, derivation, and compilation have been conducted and distributed by a variety of partners. In the nearshore (~15-250 m), a major objective has been to develop high-resolution maps to characterize reefs and associated habitats to meet the coral reef conservation goals of NOAA and the American Samoa government. At depths of 0-15 m, bathymetry has been derived from high-resolution, multispectral Ikonos satellite imagery, by gauging the relative attenuation of blue and green spectral radiance as a function of depth. This was also in support of NOAA Coral Reef Conservation Program goals. In deeper environments (250 m or greater), the goal has been to describe and interpret the geomorphology of mid- to deep- water flanks surrounding Tutuila, and further to compile regional bathymetry for geomorphological studies of the Eastern Samoa Volcanic Province, including the identification and shape characterization of previously undocumented seamounts and considerations of age-progressions based on arrangements of volcanic lineaments. However, these data sets can also serve as critical inputs to tsunami inundation models and subsequent simulations and data sets. To wit, the National Geophysical Data Center has just released 10- and 30-m integrated bathymetric–topographic digital elevation models (DEMSs) of Pago Pago, American Samoa, primarily for the NOAA Pacific Marine Environmental Laboratory Center for Tsunami Research. The best available digital data were compiled from various sources, shifted to common horizontal and vertical datums, with final edits before preparation of the DEMs. Such datasets will be important to further build the capacity for disaster preparation and response needed by local government officials, in addition to a territory-wide GIS infrastructure needed by the various agencies within the American Samoa Government, the American Samoa Coastal Zone Management Program, the American Samoa Power Authority, and U.S. federal agencies in the region.

INDEX TERMS: [3045] MARINE GEOLOGY AND GEOPHYSICS / Seafloor morphology, geology, and geophysics, [7240] SEISMOLOGY / Subduction zones, [1910] INFORMATICS / Data assimilation, integration and fusion.

Download presentation file (3.8 Mb)
Related web site
seafloormapping.net


Return to Dawn's Vita