HISTORIC AND GEOMORPHOLOGICAL LEGACY OF A FORMER WAVE-DOMINATED CRANBERRY INLET, NEW JERSEY

The wave-dominated barrier coast of central New Jersey contains several historic and relict tidal inlet complexes, however exact locations, depth, and migration history of these dynamic systems are not well known. These include a multiple inlet system that provided navigation, water exchange, and sediment transport between Barnegat Bay and Atlantic Ocean. Most inlets open during intense storms, with the hypsometry of the bayside and longshore transport responsible for their longevity and ultimate closure. This study focuses on the historic Cranberry Inlet (also known as New or Toms River Inlet), which was located south of the recent Mantoloking breach (Superstorm Sandy, 2012), between the present Barnegat Inlet in the south and a historic Herring Inlet in the north. The time of its opening is much debated and varies from 1740 to 1760, with independent historic evidence suggesting an earlier date. The migration history, if any, and the final location of this channel, a key artery for several Revolutionary War battles, are relatively poorly constrained. It started filling up a few years before 1812, gradually shoaling before closure. In subsequent decades there were several failed attempts to reopen this channel, likely due to strong longshore transport, shallow bay bathymetry, and effectiveness of the tidal prism exchange through Barnegat Inlet. In the bay, behind an 800-1000-m-wide section of Ortley Beach, there is a number of undeveloped marsh-covered islands with flying spits, as well as a highly developed lobate region, terminating in the north with the horseshoe-shaped West Point Island, possibly a relict ebb-shield and ebb-spit of the flood-tidal delta. In addition to archival research of historic charts and documents, this study will employ 250-500 MHz ground-penetrating radar imaging to test whether a channel sequence can be identified below an intensely developed barrier segment and to help locate the final position of the inlet. Ultimately, our research will have implications to legal and tidal boundaries, groundwater distribution and saltwater intrusion anomalies (fining-upward channel sequence vs. inversely graded barrier lithosome), and the vulnerability of this barrier – one of the hardest hit sections during Superstorm Sandy – to rising sea level and storm impact.