Sea level rise in Tampa Bay

Abstract

Understanding relative sea level (RSL) rise during periods of rapid climatic change is critical for evaluating modern sea level rise given the vulnerability of Antarctic ice shelves to collapse [ Hodgson et al, 2006], the retreat of the world's glaciers [ Oerlemans, 2005], and mass balance trends of the Greenland ice sheet [ Rignot and Kanagaratnam, 2006]. The first-order pattern of global sea level rise following the Last Glacial Maximum (LGM, ∼21,000 years ago) is well established from coral [ Fairbanks, 1989], continental shelf [ Hanebuth et al, 2000], and other records [ Pirazzoli, 2000] and has been integrated into a global ICE-5G model of glacio-isostatic adjustment (GIA) [ Peltier, 2004]. However, uncertainty introduced by paleo water depth of sea level indicators, radiocarbon chronology (i.e., reservoir corrections for marine shell dates), postglacial isostatic adjustment, and other processes affecting vertical position of former shorelines produces scatter in RSL curves, limiting our knowledge of sea level rise during periods of rapid glacial decay. One example of this limitation is the Gulf of Mexico/Florida region where, despite decades of study, RSL curves produce two conflicting patterns: those showing progressive submergence with a decelerating rate during the past 5000 years [ Scholl et al, 1969] and those showing high sea level during the middle of the Holocene [ Blum et al, 2001; Balsillie and Donoghue, 2004], where the Holocene represents a geologic epoch that extends from about 10,000 years ago to present times. This discrepancy is emblematic of the uncertainty surrounding Holocene sea level and ice volume history in general.