Increase in the rate and uniformity of coastline erosion in Arctic Alaska

TLDR

Arctic changes such as declining sea ice, warmer summers, rising sea level, and stronger storms may drive increased erosion. Erosion rates along the Beaufort Sea coast rose from 6.8 m yr⁻¹ in 1955–1979 to 13.6 m yr⁻¹ in 2002–2007, became more uniform across shoreline types, and even occurred without storms, indicating a new ocean‑land interaction regime.

Abstract

Analysis of a 60 km segment of the Alaskan Beaufort Sea coast using a time‐series of aerial photography revealed that mean annual erosion rates increased from 6.8 m a −1 (1955 to 1979), to 8.7 m a −1 (1979 to 2002), to 13.6 m a −1 (2002 to 2007). We also observed that spatial patterns of erosion have become more uniform across shoreline types with different degrees of ice‐richness. Further, during the remainder of the 2007 ice‐free season 25 m of erosion occurred locally, in the absence of a westerly storm event. Concurrent arctic changes potentially responsible for this shift in the rate and pattern of land loss include declining sea ice extent, increasing summertime sea surface temperature, rising sea‐level, and increases in storm power and corresponding wave action. Taken together, these factors may be leading to a new regime of ocean‐land interactions that are repositioning and reshaping the Arctic coastline.