Title

Land subsidence made a major contribution to sea level rise in the 20 th century at Galveston Pier 21, Texas

Document Type

Conference Paper

Publication Date

2019

Date Added

2022-09-07

Abstract

It is suggested that sea level rise consists of absolute sea level rise due to global warming, basement rock subsidence due to regional tectonic downward motion, primary consolidation subsidence due to subsurface fluid withdrawal, and secondary consolidation subsidence due to geo-historical overburden pressure. Both primary and secondary consolidation subsidence are from compaction of compressible aquifer systems. At Galveston Pier 21, Texas, sea level rose 4.60 mm/a during both 1909 to 1937 and 1983 to 2000 but 7.16 mm/a high during only 1937 to 1983 from tide gauge data. The extra 2.56 mm/a during 1937 to 1983 is attributed to primary consolidation subsidence. Basement rock subsidence was estimated to be 2.67 mm/a from GPS SG32 elevation measurements at College station 132 km far from Galveston Pier 21. Absolute sea level would be 1.16 mm/a through removing GPS TXGA observed land subsidence of 3.44 mm/a from the above sea level rise of 4.60 mm/a. GPS TXGA is 3 km far from Galveston Pier 21. The secondary consolidation subsidence at Galveston Pier 21 would be 0.77 mm/a if the basement rock subsidence of 2.67 mm/a can be removed from the land subsidence of 3.44 mm/a. Land subsidence contributed 75% to sea level rise during 1909 to 1937 and 1983 to 2000 but 85% during 1937 to 1983. This implies that land subsidence made a major contribution to sea level rise in the 20th century at Galveston Pier 21, Texas.

Keywords

Climate

Disciplines

Engineering

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