A two-million-year volcano became Korea’s subtropical holiday isle
Jeju Island, South Korea’s largest at 1,833.2 square kilometres (1.83% of national area), sits in the Korea Strait about 82.8 kilometres south of the peninsula. Formed by a submarine volcano roughly two million years ago, it holds UNESCO-listed Jeju Volcanic Island and Lava Tubes.
The oval island spans about 73 kilometres from east to west, and its coastline runs 258 kilometres. Hallasan, 1,947 metres tall and the highest peak in South Korea, rises gently from the centre, surrounded by some 360 oreum, small extinct cones such as Geomunoreum that draw hikers. Seongsan Ilchulbong marks the eastern tip and Suwolbong the western.
The building happened in pulses. A magma chamber under the seabed began erupting about 1.2 million years ago; by 700,000 years ago an island existed, then eruptions paused for roughly 100,000 years. Coastal vents reawakened about 300,000 years ago, Hallasan itself grew about 100,000 years ago, and flank eruptions around 25,000 years ago scattered the oreum. The rock is mostly basalt.
About 12 percent of the land, some 224 square kilometres, is gotjawal forest on rough ’a’a lava too broken to farm until this century. Rain drains through cracks in that lava into the aquifer, making these woods the main water source for around half a million islanders. Many species bear the names quelpartensis or jejuensis, from an earwig to a local mouse, and several live nowhere else.
Seogwipo on the south coast has South Korea’s warmest January average, because Hallasan blocks winter winds that chill Jeju City in the north, and it is also among the wettest spots in the country. Neolithic people settled early, the Jeju language is rated critically endangered, and shamanism survives here more fully than in most of Korea. Old names include Samdado, island of three abundances. Portuguese sailors called it Ilha de Ladrones, and Europeans knew it as Quelpart, a name recorded in Dutch by 1648 and possibly borrowed from a type of small ship, until Japan’s 1910 annexation brought the name Saishū. Tourism now drives much of the economy.
Source: Jeju Island
