Recorded June 1, 2019 August 18, 2019

Video shows a series of photos taken every hour during daylight hours in the summer of 2019. The camera looks westward along the coastal bluffs of Barter Island, located on Alaska’s North Slope. A pole on the bluff, visible in the first half of the video, once supported another video camera that was aimed at the shoreline to study wave and shoreline dynamics. This video starts on June 1st at 4°C (25° F) when the bluffs are still frozen, snow is on the ground, and the winter pack ice protects the permafrost cliffs from wave attack. By the end of June, the ice and snow are gone, temperatures often climb to 12°C (54° F), and waves begin to lap at the narrow beach below the bluffs. In midJuly, the nowthawed, upper active layer of the tundra begins to slough off onto the beach. By the end of July, waves accompanied with elevated stormtides erode the lower part of the slope. Just days later, as erosion increases rapidly, the bluff supporting the camera gives way and the camera tumbles onto the beach. Despite its fall onto the muddy beach, the camera continued to record and was successfully recovered in order to create this video. The USGS is studying this highly erosive stretch of Arctic coastline to try to better understand the main driving forces behind the erosion and why erosion rates seem to be increasing. The increase is likely the result of several changing arctic conditions, including declining seaice extent, increasing summertime seasurface temperature, rising sea level, and possible increases in storm power and corresponding wave action. More longterm work is needed to understand the interplay of these factors and how they drive changes in coastal erosion.

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