Kuril Islands

The Kuril Islands, a volcanic archipelago in Russia’s Sakhalin Oblast, run roughly 1,300 km northeast from Japan’s Hokkaido to Russia’s Kamchatka Peninsula. This chain separates the Sea of Okhotsk from the northern Pacific Ocean and includes 56 islands plus many smaller islets. The group splits into the Greater Kuril Chain and, at its southwestern end, the parallel Lesser Kuril Chain. The so-called “South Kurils” comprise the Lesser Kuril Chain along with Kunashir and Iturup from the Greater Kuril Chain. The Vries Strait, between Iturup and Urup, marks the Miyabe Line, dividing the North and South Kurils. The islands cover about 10,503.2 square kilometers and hold a population of roughly 20,000.

Russia has administered the islands since the Soviet Union invaded them in 1945, near the end of World War II. Japan continues to claim the four southernmost islands—Iturup, Kunashir, Shikotan, and the uninhabited Habomai islets—as its own territory, calling them the “Northern Territories.” This dispute remains ongoing.

The name “Kuril” comes from the Ainu word *kur*, meaning “man,” and may relate to other Ainu-inhabited islands like Sakhalin (Kuyi or Kuye) and Hokkaido (Kai). In Japanese, they are called the Chishima Islands (“Thousand-Island Archipelago”) or Kuriru Islands. Russian explorers in the 18th century derived their name from the Russian verb *kurit’* (“to smoke”), referencing the constant volcanic plumes.

Geologically, the Kurils are part of the Pacific Ring of Fire. The islands are the tops of stratovolcanoes formed by the Pacific Plate subducting under the Okhotsk Plate, creating the Kuril Trench about 200 km east. The chain hosts roughly 100 volcanoes, around 40 active, along with many hot springs and fumaroles. Earthquakes are common, including a magnitude 8.5 quake in 1963 and an 8.3 on November 15, 2006, which sent tsunami waves up to 1.5 meters high to California. Raikoke Island’s active volcano erupted again in June 2019, sending emissions 13,000 meters high.

The climate is harsh: long, cold, stormy winters and short, foggy summers. Annual precipitation averages 40 to 50 inches, mostly snow. Most of the Kurils have a subarctic climate (Dfc), though Kunashir is humid continental (Dfb). The climate resembles southwest Alaska’s subpolar oceanic type more than interior Siberia’s hypercontinental one, with heavy precipitation and no permafrost. Summers are mild, with only one to three months above 10°C, while winters are cold, snowy, and extremely windy, typically below -3°C but above -10°C.

Vegetation ranges from tundra in the north to dense spruce and larch forests on the larger southern islands. The highest points are Alaid Volcano (2,339 m) on Atlasov Island in the north and Tyatya volcano (1,819 m) on Kunashir in the south. Habitats include beaches, rocky shores, cliffs, wide rivers, fast streams, forests, grasslands, alpine tundra, crater lakes, and peat bogs. Soils are productive due to volcanic ash and, in some areas, seabird guano, but steep slopes are prone to landslides, and new volcanic activity can strip landscapes bare. Only the southernmost island has extensive tree cover; northern islands are treeless or sparsely wooded.

Atlasov Island (Araido in Japanese), the northernmost, is a near-perfect volcanic cone rising straight from the sea. Japanese artists have depicted it in haiku, woodblock prints, and other forms, much like Mount Fuji. Its summit is the highest point in Sakhalin Oblast.

Marine life thrives in the surrounding waters, among the most productive in the North Pacific, thanks to the Pacific shelf edge, the Okhotsk Sea gyre, and the southward Oyashio Current. Extensive kelp beds around nearly every island provide habitat for sea urchins, mollusks, and other invertebrates, as well as their predators. Many squid species are a key food for smaller marine mammals and birds. Offshore, walleye pollock, Pacific cod, and several flatfish species are commercially important. In the 1980s, migratory Japanese sardine was abundant in summer. Pinnipeds were a major resource for the indigenous Ainu, providing food, skin, and bone.