Dokdo (Takeshima)

(CC) Image: Chunbum Park
Coordinates: 37° 14´ N, 131° 52´ E

Dokdo is a small group of volcanic rocks located in the Sea of Japan. South Korea administers the islets as an area of the Ulleung County, Northern Gyeongsang Province. The 56-acre (226600 m²) formation consists of two main islands that house a lighthouse, a helicopter pad, and a small police force. Because the rocks shelter various species of fish, birds, plants, and insects, the South Korean government has designated the islets as a nature reserve and enforces measures to protect the islets from the visiting tourists. The sovereignty over Dokdo has been contested by Japan over historical and legal grounds and remains one of the more serious disputes between South Korea and its former colonial ruler. Since at least 1905, the islands were called in Japanese Takeshima (竹島), meaning the "bamboo island". The Korean name has many different transliterations in English, including "Tok-do", "Dok-to", and "Tok Islets" (독도), all of which equate to "rocky island". The islets have two English titles: Liancourt Rocks and Hornet Rocks. "Liancourt" has its origin in the name of the French whaling ship that first encountered and charted the islets in 1849.

Geography

(CC) Image: Chunbum Park
A detailed map of Dokdo.

Template:2isletsdata Dokdo lies in the Sea of Japan as a part of an underwater volcano that erupted repeatedly from 4.6 to 2.5 million years ago. The underwater Dokdo volcano stands 2 km high on its base with a diameter of 20 ~ 25 km and rises to a guyot summit that is 10 km wide. The islets on top of this summit consist mostly of trachyte and trachyandesite differentiated from the parental alkali basalt magma of the underwater volcano. Samples of these rocks reveal that Dokdo is the oldest existing island in Korea (Awaji Island is the oldest in Japan); the second oldest island in Korea is Ulleungdo, which formed 2 million years after Dokdo from the same hot spot, with similar igneous composition to Dokdo. Due to sedimentation, the 2 islands (Seo-do and Dong-do　in Korean, Otoko-jima and Onna-jima in Japanese; both literally meaning western island　and eastern island, respectively) that make up most of the island cluster above water split 2 million years ago, and are now positioned 151 meters apart from each other. The western islet is steeper and larger than the eastern islet, and it is the tallest islet in the cluster. 87 smaller rocks scatter around the two main islands within a radius of a few kilometers, and more than 30 of such geographical features have been named by the South Korean government ministries.

Climate & Ecology

Dokdo has a moderate maritime climate created by the warm and cold ocean currents that collide nearby the islands. The average year-round temperature is 12°C, and the coldest and the hottest extremes occur in January (1°C) and August (23°C) respectively. The average yearly rainfall is 1,240 mm, and in the winter the islands experience a heavy snowfall. In a year, there are only about 50 clear days, more than 160 days are cloudy or foggy, and rain or snow falls on the remaining 150 days.

Dokdo's ecology is influenced heavily by its climate and geography. Because of the strong, salty sea winds (with an average velocity of 4.3m/s), the barren soil, and the lack of fresh water, vegetation grows poorly on the islets. There were originally only a few types of plants on the islets, but many more have been transplanted to Dokdo from the mainland since the S. Korean occupation. The islands can undergo severe drought if no rain or snow falls for a while because the thin layer of soil cannot retain much water and the amount of water produced by the moss that covers the islands is very little. The However, due to its central location in the Sea of Japan, Dokdo is an important bird-breeding area and also a popular rest stop for the birds flying in the north-south direction. The black-tailed gulls that nest and breed on the islets between May and August are the largest avian population in Dokdo. The areas around Dokdo, where the North Korean Cold Current and the Tsushima Warm Current collide, and planktons are abundant, contain a diverse marine life including the Pacific white-sided dolphins, octopus, pollack, saury, abalone, turbo, and sea cucumber. However, the stellar sea lions and the fur seals that are native Dokdo have disappeared from the islands completely.

8 of the species found in Dokdo are very likely to become extinct in Korea (endangered classes 1 & 2), including the falcons, Siberian honey buzzards, owls, black kites, Japanese murrelets, and swans. Currently, Dokdo is inhabited by 107 species of birds, 49 species of plants (of which 19 are alien species), and 93 species of insects; and as many as 160 different species of seaweeds and 100 species of fish live in the surrounding waters. There are some concerns about the possible harms on the islands' ecosystem that the 19 alien plant species could inflict as invasive species. Dokdo's ecology