UMD AOSC Seminar
Late Holocene Sea Level Rise: History, Processes, Future
Professor Michael S. Kearney
University of Maryland
A global acceleration in the rate sea level rise is one consequence of AGW that will have worldwide consequences. Models highlighted in the last two assessments of the IPCC have forecast the trajectory of future sea level changes through the end of this century, but many coastal scientists consider these models only useful as provocative scenarios and not realistic instruments for risk analyses and vulnerability assessments compared to extrapolating existing regional and local trends. This latter approach, unfortunately, has some problems, probably the greatest of which is that it can only be applied to a limited time horizon of at most the next 30 years. New insights on factors (e.g., the amount of polar melting) critical to determining the magnitude of future sea level changes are emerging that promise to reduce the uncertainties about the global sea level trend after c. 2050 CE, and improve sea level rise prediction for the remainder of the century. Nonetheless, more long range forecasts, especially well into the 22nd century, may hinge on understanding the present transgression as it compares to prior sea level high stands during the late Holocene (c. 5000 yr BP – present). One question that still begs answering is how long the present sea level trend, which began about c. 1850 CE, will continue now that anthropogenic forcing may have added something new to the mix of climate – ocean responses. This presentation will discuss what we know about late Holocene sea level change, how phenomena like postglacial rebound posed problems in its reconstruction, and how appreciation of the nature of the evidence has permitted better understanding of the timing and size of seemingly large-scale departures in past ocean levels. Lastly, new ways of looking at sea level changes since the era of the recording tide gauge have become available, and the presentation will look at what they reveal about intra-decadal and inter-annual sea level variability, and how it relates to delineating accelerations in the rate of rise.
Thursday, October 25, 2012
AOSC494: Atmospheric and Oceanic Science Seminar
AOSC 818: Frontiers in Atmosphere, Ocean, Climate, and Synoptic Meteorology Research