Large driftwood accumulations along arctic coastlines and rivers

Abstract

Abstract Driftwood deposits along Arctic coastlines play key ecological roles and serve as indicators of past environmental conditions. Yet, there is a lack of knowledge regarding large-scale distribution patterns, which are important to assess its ecological and geomorphic impacts and carbon stocks. Here, we present a systematic mapping of Arctic driftwood in the North American low Arctic using PlanetScope nano-satellite imagery. We identify 19,717 driftwood deposits covering 22,960,000 m2 . Driftwood accumulates in clusters near major river deltas, strongly correlating with boreal forest cover within river catchments. Accumulation declines sharply beyond 200 km from river mouths, challenging current narratives of predominantly long-range redistribution. We compare the performance of driftwood-mapping using PlanetScope imagery with sub-metre aerial imagery. Our method underestimates the total driftwood area by 23.18% but captures large deposits with high accuracy (-4.28% bias). Our assessment highlights the abundance of driftwood on Arctic coastlines and forms a baseline for exploring its temporal variability across large regions, its role in coastal erosion mitigation, and its importance as a carbon sink.