Jeju Island

Jeju Island (Jeju/; ) is South Korea's largest island, covering an area of 1833.2 km2, which is 1.83% of the total area of the country. Alongside outlying islands, it is part of Jeju Province.

The island lies in the Korea Strait, south of the Korean Peninsula, and South Jeolla Province. It is located 82.8 km off the nearest point on the peninsula. Jeju is one of two special self-governing provinces in South Korea, meaning that the province is run by local politicians. The Jeju people are indigenous to the island, and it has been populated by modern humans since the early Neolithic period. The Jeju language is considered critically endangered by UNESCO. It is also one of the regions of Korea where Shamanism is most intact.

Jeju Island has an oval shape of 73 km east–west and 31 km north–south, with a gentle slope around Hallasan Mountain in the center. The length of the main road is 181 km and the coastline is 258 km. On the northern end of Jeju Island is Gimnyeong Beach, on the southern end Songak Mountain, the western end Suwol Peak, and the eastern end Seongsan Ilchulbong.

The island was formed by the eruption of an underwater volcano approximately 2 million years ago. It contains a natural World Heritage Site, the Jeju Volcanic Island and Lava Tubes. Jeju Island has a temperate climate which is moderate; even in winter, the temperature rarely falls below 0 C. Jeju is a popular holiday destination and a sizable portion of the economy relies on tourism and related economic activity.

Historical names
Historically, the island has been called by many different names including:
 * Doi
 * Dongyeongju
 * Juho
 * Tammora
 * Seomna
 * Tangna
 * Tamna
 * Quelpart,  Quelparte or Quelpaert Island
 * Junweonhado ( meaning "southern part of peninsula")
 * Taekseungnido (, meaning "the peaceful hot island in Joseon")
 * Samdado meaning "Island of Three Abundances")
 * Sammudo
 * Cheju (spelling until 7 July 2000)

Before the Japanese annexation in 1910, the island was usually known as Quelpart (Quelpaërt, Quelpaert) to Europeans; during the occupation it was known by the Japanese name Saishū. The name Quelpart coming from French language is attested in Dutch no later than 1648 and may have denoted the first Dutch ship to spot the island, the quelpaert de Brack around 1642, or rather some visual similarity of the island from some angle to this class of ships (a small dispatch vessel, also called a galiot).

The first European explorers to sight the island, the Portuguese, called it Ilha de Ladrones (Island of Thieves).

The name "Fungma island" appeared in the "Atlas of China" of M. Martini who arrived in China as a missionary in 1655.

History
Jeju Island has been inhabited by modern humans since the early Neolithic period. There is no discovered historical record of the founding or early history of Tamna. One legend tells that the three divine founders of the country—Go (고), Yang (양), and Bu (부)—emerged from three holes in the ground in the 24th century BC. These holes, known as the Samseonghyeol (삼성혈), are still preserved in Jeju City. Until 938 AD, the island was an independent kingdom called Tamna (which means 'island country') when it became a vassal state of Korea under the Goryeo dynasty. In April 1330, in the midst of political purges of the Yuan dynasty, Toghon tomor had been sent in Exile on this remote island, which was then part of the vassal Korean Goguryeo. In 1404, Taejong of Joseon placed the island under firm central control and brought the Tamna kingdom to an end.

In April 1948, it was the site of the Jeju uprising.

Landscape
Jeju is a volcanic island, dominated by Hallasan: a volcano 1,950 m high and the highest mountain in South Korea. The island measures approximately 73 km across, east to west, and 41 km from north to south. The island also has around 360 oreum: small extinct volcanoes or parasitic cones. Many of these are now popular tourist attractions, such as Geomunoreum, Yongnuni Oreum, and Geum Oreum.

The island formed by volcanic eruptions approximately two million years ago, during the Pleistocene epoch. The island consists chiefly of basalt and lava.

An area covering about 12% (224 km2) of Jeju Island is called gotjawal, a local term for forests. This area remained uncultivated until the 21st century, as its base of 'a'a lava made it difficult to develop for agriculture. Because this forest remained pristine for so long, it has a unique ecology.

The forest is the main source of groundwater and thus the main water source for the half million people of the island, because rainwater penetrates directly into the aquifer through the cracks of the 'a'a lava under the forest. Gotjawal forest is considered an internationally important wetland under the Ramsar Convention by some researchers because it is the habitat of unique species of plants and is the main source of water for the residents, although to date it has not been declared a Ramsar site.

Formation

 * About 2 million years ago, the island of Jeju was formed through volcanic activity.
 * About 1.2 million years ago, a magma chamber formed under the sea floor and began to erupt.
 * About 700 thousand years ago, the island had been formed through volcanic activity. Volcanic activity then stopped for approximately 100 thousand years.
 * About 300 thousand years ago, volcanic activity restarted along the coastline.
 * About 100 thousand years ago, volcanic activity formed Hallasan Mountain.
 * About 25 thousand years ago, lateral eruptions around Hallasan Mountain left multiple oreum (smaller 'parasitic' cones on the flanks of the primary cone).
 * Volcanic activity stopped and prolonged weathering and erosion helped shape the island.

Climate
Most of Jeju Island has a humid subtropical climate (Cfa in the Köppen climate classification). Four distinct seasons are experienced in Jeju; winters are cool with moderate rainfall, while summers are hot and humid with very high rainfall.

Jeju City, the northern part of the island, tends to be colder in winter than the southern part due to the influence of continental seasonal winds. Gosan-ri, located on the west side of the island, has the lowest annual average precipitation on the island, but unlike most parts of mainland Korea, the seasonal precipitation is even. The Chuja Islands, which belong to Jeju City, are an archipelago located between mainland Korea and Jeju Island and also have a humid subtropical climate (Cfa).

Seogwipo, the southern part of the island, is relatively warmer in winter than Jeju City because Hallasan in the middle of the island prevents continental seasonal winds. The downtown of Seogwipo has the highest average temperature in January in Korea, including mainland Korea. Seongsan-eup, the southeastern side of the island, is directly affected by both the East Asian monsoon and the Tsushima Current, so annual precipitation is very high. Seogwipo is one of the regions with the highest annual precipitation in Korea.

The climate of the highlands in the middle of the island where Hallasan is located is quite different from those of the rest of the island. The higher the altitude, the lower the average temperature and the colder the climate. The highlands of Jeju Island have the highest annual precipitation in Korea.

In January 2016, a cold wave affected Jeju Island. Snow and frigid weather forced the cancellation of 1,200 flights on Jeju Island, stranding approximately 90,300 passengers.