SEDIMENTARY RECONSTRUCTIONS OF NOR'EASTER OCCURRENCE IN NEW ENGLAND

Nor’easters can cause billions of dollars in damages and disrupt communities along the coastline of the northeastern United States. However, Nor’easter strength and frequency has only been measured for ~50 years, how Nor’easters might respond to and be influenced by climate change remains poorly understood. To further study this, we collected and analyzed sediment cores from coastal ponds along the Gulf of Maine. These ponds were sampled to reconstruct Nor’easters due to their location on east-facing coast lines where washover from Nor’easters deposit distinct sediments into the pond. We are using grain size analysis and organic content on these cores to identify distinct ‘event beds’ characterized by coarse grain-size and low organize content to reconstruct Nor’easter occurrence during the late Holocene. We use short-lived radioisotopes (137Cs, 210Pb) and radiocarbon (14C) to age-date the sediments and understand sedimentation rate and timing of the deposits. In one core from Swampscott, Massachusetts (Palmer Pond), we present evidence of two Nor’easter event-beds that likely correspond to the two largest surge events on record in this region: Winter Storm Grayson in 2018, and the Storm of ‘78 (1978). These two events occur near the top of the core, with no similar events below this until a sharp contact with glacial clay dated to ~6.0 kyr, implying that these recent storms may have generated the largest washover events at this location of the late Holocene. This research demonstrates that coastal ponds record sedimentary deposits from Nor’easters, allows us to investigate the history of Nor’easters in coastal New England, and will help us to understand the role of climate change on Nor’easter intensity and frequency.