The many uses of driftwood: the first large-scale mapping of Arctic coastlines

AWI researchers establish a basis for systematically recording driftwood's ecological roles and better tracking any future changes

Driftwood Accumulations along Arctic Coasts (Photo: Alfred-Wegener-Institut / Carl Stadie)

Driftwood plays a key role in Arctic coastal ecosystems: it stores carbon, stabilises coastlines and provides a habitat for animals. At the same time, it can offer clues regarding climate change in the Arctic region, providing information on the likes of storm surges, coastal erosion and shifting fluvial dynamics. Despite the crucial role it plays, there is still a lot that we do not know about the large-scale distribution patterns of driftwood. Now, for the first time, researchers from the Alfred Wegener Institute have systematically mapped driftwood deposits along an 11,000 kilometre stretch of coastline in Alaska and North West Canada, using satellite imagery and AI-powered evaluation methods. The result is the largest database ever produced, with researchers able to identify over 19,000 stable driftwood deposits. The findings will soon be published in the Scientific Reports journal.

An astonishing amount of driftwood accumulates along Arctic coastlines, primarily composed of pine, fir and larch logs from forests. These logs travel down rivers into the ocean, where they ultimately end up deposited along the coastline, either as individual logs or dense blankets of wood. Covering areas of up to 15 hectares, some of the larger clusters are similar in size to 20 football pitches. “Our study provides the most comprehensive overview of driftwood distribution and accumulation patterns in the Arctic to date,” says Carl Stadie, the study’s lead author and PhD student in the Permafrost Research Section of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). To achieve this, the team gathered roughly 2.3 terabytes of satellite data between 2019 and 2023, which in total covered 1.3 million square kilometres of coastal areas of the North American Arctic. “We then used this data to train a neural network to automatically recognise driftwood in these images.”

[Translate to English:] Treibholz Artkis — Driftwood Arctic (Photo: Alfred-Wegener-Institut / Carl Stadie)

The researchers used high-resolution aerial imagery taken during AWI flight campaigns to verify how reliably the network carried out this task. They discovered that, in fact, driftwood is not randomly distributed along Arctic coastlines, but rather mainly accumulates near large river deltas. The team identified over 19,000 driftwood deposits that covered an area of close to 23 square kilometres between 2019 and 2023 and remained in the same place and stable throughout these years. “Rivers are the most important transport system for driftwood travelling to the oceans,” explains Carl Stadie. “However, once it reaches open waters its waterways are still unclear. To figure out whether driftwood remains near its source river or is distributed further away, we looked for a correlation between the areas covered with driftwood and the distance from the nearest river mouth.”

The images showed that over 80% of total driftwood actually accumulated within 200 kilometres of the river mouth. The spacial density of deposits reduced significantly, the further away from the river mouth they were. “This suggests that driftwood may be distributed via ocean currents or ice less commonly than previously thought,” concludes Carl Stadie. However, it is not just the density of deposits that varies depending on the location, but the type of deposit too: deposits in river deltas tend to be smaller and more densely packed, while larger, more stable mats are found on open coastlines. The amount of wood deposited was heavily dependent on how densely forested the catchment areas were.

“Our deep learning approach is the most comprehensive assessment of driftwood in the Arctic,” summarises Carl Stadie. “It shows us how and where driftwood accumulates and provides a data basis to systematically record its ecological roles and better track any future changes.” In the long term, this approach opens up the possibility of using driftwood as an indicator of climate-induced changes to rivers, forests and coastal landscapes.

Original publication

Carl Stadie, Martin Brandt, Ingmar Nitze, Xiaoye Tong, Siyu Liu, Ankit Kariryaa, Sizhuo Li, Florian Reiner, Tabea Rettelbach, Guido Grosse: Large driftwood accumulations along arctic coastlines and rivers. Sci Rep 15, 32500 (2025). https://doi.org/10.1038/s41598-025-17426-y