Kunashir Island's Growth Narrows Gap to Hokkaido

The coastline of Kunashir Island is physically shifting. Over the last 50 years, the southern tip of the Veslovsky Peninsula has extended approximately 380 meters further into the sea, driven by marine currents that continuously deposit sand and expand the landmass. This growth has narrowed the gap between the easternmost point of Kunashir and the Japanese island of Hokkaido to roughly 16 kilometers. This accretion of sand has fundamentally altered the hydrography of the Izmeny Strait. As the land pushed outward, vast sandbars formed in the surrounding waters, creating shallow zones where depths in certain areas have dropped to just a few meters. These physical constraints have effectively closed the route to large-tonnage vessels, limiting navigation to small craft. While the gradual accumulation of sediment reshapes the peninsula, more abrupt volcanic activity is expanding other parts of the Kuril chain. On Raikoke Island, a 2019 eruption increased the total land area by approximately 15%, while a 2009 eruption on Matua Island added between 2% and 3% to its territory. On Iturup, the interaction of sea waves and volcanic debris has resulted in the formation of new coastal ridges.