Dokdo Foundation

01 Climate

Temperature The annual average temperature is 12.2℃, with an annual low of 13.6℃ and high of 34.6℃.
Precipitation The annual average amount of rainfall is 1,240.8 millimeters (September is the month with the highest precipitation).
Wind Speed Winds blow at an annual average of 4.3m/s, mainly from the southwest in summer and from the northeast in winter.
Surface Water Temperature The lowest reaches 10℃ in March-April and the highest climbs to 25℃ in August.
Salt Concentration of Surface Water It is 33-34% with 6.0㎖/l oxygen level in the surface layer and 17-20m transparency (high salt concentration level allows the formation of clean waters).
Ocean Currents  The Tsushima Current, a branch of the Kuroshio, flows through the Straits of Korea, moving northward.
 In winter, it turns toward the east around Dokdo.
 In summer, the Tsushima Current circles in the north of Dokdo.
 In the north of Dokdo, the North Korea Current, a vein of the Liman Cold Current, whirls counterclockwise, helping a number of maritime plants to form around Dokdo.

02 Geology

Composition is comprised of nine alkali volcanic rocks formed by volcanic activities, namely basalt and trachyte.
Peak of Dongdo  The highest point of the island is 98.6 meters above sea level, with a relatively flat surface.
 The tip of Dongdo is layered with 20-30 centimeters of soil, creating a habitat for herbal plants.
 On the seaward slope, the island features steep cliffs, many of which are about 30 meters in height with a thin layer of soil, if any, and extremely poor vegetation covering.
Peak of Seodo  The highest point of the island is 168.5 meters above sea level, with a narrow and sharp ridge.
 As its southwestern area, reaching 100-140 meters above sea level, is relatively flat, herbal plants can grow.

03 Sea-floor Topography

The First Dokdo Seamount
(Dokdo Haesan)
 It is at 37º 15′ N and 131º 52′ E.
 The tip of the First Dokdo Seamount, exposed above the sea surface, is Dokdo.
 Its western rim is 2,100 meters below the surface, and a submarine valley at a depth of 800 meters separates the eastern part of Dokdo Haesan and the western part of Tamhae Haesan.
 Its summit features a fairly gentle and flat wave-cut platform with a slope of less than two degrees, which is 60 to 200 meters below the sea surface.
 A number of submarine gullies are formed and connected to the deep-sea Ulleung Basin.
The Second Dokdo Seamount
(Tamhae Haesan)
 It is at 37º 9′ N and 132º 2′ E.
 It is 15 kilometers southeast of Dokdo Haesan
 Its eastern rim is some 800 meters below the surface.
 It has a slope of some 13 degrees and summit of about two degrees, without any part exposed above the sea surface.
The Third Dokdo Seamount
(Donghae Haesan)
 It is at 37º 11′ N and 132º 20′ E.
 It is located at the western boundary of the Oki Bank, 55 kilometers away from the First Dokdo Seamount.
 The upper plateau of the volcanic formation is the largest among the Dokdo seamounts, while its height is the lowest, rising some 600 meters from the bedrock.