HR: 0800h
AN: G51A-0142    [Abstracts]
TI: GPS and Tide Gauge Constraints on Subsidence and Relative sea Level Rise Along the US East Coast
AU: * Jiang, Y
EM: yjiang@rsmas.miami.edu
AF: University of Miami, Rosenstiel School of Marine and Atmospheric Science, Marine Geology and Geophysics, 4600 Rickenbacker Causeway, Miami, FL 33149, United States
AU: Wdowinski, S
EM: swdowinski@rsmas.miami.edu
AF: University of Miami, Rosenstiel School of Marine and Atmospheric Science, Marine Geology and Geophysics, 4600 Rickenbacker Causeway, Miami, FL 33149, United States
AU: Dixon, T H
EM: tdixon@rsmas.miami.edu
AF: University of Miami, Rosenstiel School of Marine and Atmospheric Science, Marine Geology and Geophysics, 4600 Rickenbacker Causeway, Miami, FL 33149, United States
AU: Harrison, C G
EM: charrison@rsmas.miami.edu
AF: University of Miami, Rosenstiel School of Marine and Atmospheric Science, Marine Geology and Geophysics, 4600 Rickenbacker Causeway, Miami, FL 33149, United States
AB: Relative sea level change has two distinct components, absolute sea level variation and movement of Earth's crust. The movement of the crust can sometimes bias estimation of absolute sea level change as inferred by tide gauge data. We employ high accuracy GPS measurements (Sella et al., 2007) to detect movement of the crust in eastern North America, primarily reflecting areas that are affected by Glacial Isostatic Adjustment (GIA). In particular, these data define the collapse of the "peripheral bulge". We compare the GPS data to relative sea level change as recorded by tide gauges. We use all tide gauge stations along the east coast of North America that have more than 60 years of data, and estimate the rate of relative sea level rise using a model that accounts for annual, semi-annual and decadal signals in the time series. The GPS data show regions with subsidence rate > 2mm/year between Virginia and South Carolina, ~1900--2500km away from the uplift center in Hudson Bay. Tide gauge data in these areas show about 4mm/year relative sea level rise. The inferred global sea level rise rate is about 2mm/year. Thus, land subsidence in these regions effectively doubles the relative sea level rise rate and the corresponding natural hazard.
DE: 1200 GEODESY AND GRAVITY
DE: 1223 Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions (0762, 1218, 3319, 4550)
DE: 1225 Global change from geodesy (1222, 1622, 1630, 1641, 1645, 4556)
SC: Geodesy [G]
MN: 2007 Fall Meeting