Hurricane records on the South Carolina coast: Can they be detected in the sediment record?

More than 40 short cores were collected from 10 localities in the Myrtle Beach to McClellandville coastline of South Carolina. The localities were selected on the basis of whether or not they should have a well preserved record of recent hurricanes, most notably Hugo, which occurred in September, 1989. Of the 40 cores collected, results from two sites are presented here as examples - Price's Inlet, a non-tidal intra-beach ridge area, which was directly in the path of the eyewall of Hugo, and Sandpiper Pond which is a coastal non-tidal pond near Murrells Inlet, about 50-75 km north of where the main landfall of hurricane Hugo but still in the area of high storm surge. These cores were analyzed for percentage organic carbon, visual observations, X-rays, and microfossils. The microfossils were used to differentiate marine/non-marine sequences in the non-tidal inlets and identify reworked sediments by means of displaced benthic foraminifera. Cores were dated using Pb-210 techniques that provide resolution for the last 100 yr. In Price's Inlet the Hugo effect was most pronounced with an 8 cm thick sand layer containing many nearshore foraminifera, showing transport from offshore. In Sandpiper Pond we could see the trace of Hugo from the offshore foraminifera contained in sediments sandwiched between the freshwater intervals both before and after Hugo, however, there was little detectable trace in the X-rays or sedimentology of this core to indicate a storm event. Hence, we can recognize a range of responses for hurricanes in the form of different types of sediment layers and microfossil assemblages in these non-tidal areas depending on where the impact point is on the coast. Here we are able to distinguish at least two types of signals from the same storm which has significant implications for detecting these events in the pre-historic record and determining their paleo-periodicity. (C) 1999 INQUA/Elsevier Science Ltd. All rights reserved.