GEOARCHAEOLOGY OF DYNAMIC LANDSCAPES: SITE DISCOVERIES, INVESTIGATIONS AND FUTURE PROJECTIONS FOR COASTAL DELAWARE, USA

The Mid-Atlantic coast of the United States is experiencing higher rates of sea level rise than the global average (Engelhart et al, 2009). The Delaware Bay, the second largest estuary along the U.S. Atlantic coast, is experiencing some of the gravest effects from recently accelerated rates of sea level rise due to climate change and coastal subsidence. With the lowest mean elevation in the U.S., the wide coastal zone along the bay is subject to daily tidal action, storm surge, and long-term inundation. The estuarine shoreline encompasses 830 km² of fringing tidal marshes, much of which have been developing for ~2000 years but are now being lost at an alarming rate of up to an acre/day (Nikitina et al, 2014). Tidal marshes have been considered low probability for archaeological resources, but recent work combining traditional archaeological survey with methods of geomorphologic investigation reveals that they hold high potential for archaeological recovery and are undergoing rapid changes due to extensive salt marsh degradation, ponding, and inundation. Without the salt marsh, cultural resources will be left without protection from storm surges and wave action and the opportunity to document and study them will be lost. We discuss interdisciplinary efforts to systematically identify, document, and study sites within this threatened landscape, including their paleo-reconstructions, monitoring the most recent seasonal and decadal landscape changes, and modeling future trends of sea level and storm surge projections.