Kitakojima Island is a rhombus-shaped island rising to sharp points in the north (129 meters) and center (128 meters). Coastal areas consist of steep, rocky cliffs, largely made of sandstone and conglomerate. There are coral reefs on the north and south coast of the island, ranging from a few meters to more than 10 meters in length. (Ref. 1)
Kitakojima Island is rectangular in shape with slightly protruding corners. The distance from northwest to southeast is around 900 meters and from northeast to southwest between 300 and 500 meters. There is a sharp 124.5-meter peak in the north of the island and a 118.4-meter peak in the center. The coast consists mainly of sea cliffs. The northeast and southwest coasts are made up of coral outcroppings and are flat. (Ref. 2)
In 1979, the Japanese government's Okinawa Development Agency conducted a survey regarding potential development for usage of Uotsuri Island, Kitakojima Island, and Minamikojima Island. This survey established geodetic control points, survey markers, and photo control points with the aim of preparing a 1:5000 scale map. (A water depth survey was completed at the same time.) The topographical map below was prepared based on the agency's survey. (Ref. 3)
Kitakojima Island (above), Minamikojima Island (below)
Source: Okinawa Development Agency, Senkaku Shoto chosa hokokusho: Riyo kaihatsu kanosei chosa hen (Report on the Senkaku Islands Survey: Potential Development/Usage Survey), 1980.
Ref.1 ：Nohara Tomohide, "Senkaku Retto no chishitsu (yoho)" (Preliminary Report on Geology of the Senkaku Islands), in Senkaku Retto gakujutsu chosa hokoku (Report on the Senkaku Islands Scientific Expedition), based on a survey carried out by the University of the Ryukyus Scientific Expedition Team (Nishihara, Okinawa: University of the Ryukyus, 1971).
Ref.2 ：Matsumoto and Hayashi, Chapter 4, in Senkaku Shoto chosa hokokusho: Gakujutsu chosa hen (Report on the Senkaku Islands Survey: Academic Survey) (Okinawa Development Agency, 1980).
Ref.3 ：Senkaku Shoto chosa hokokusho: Riyo kaihatsu kanosei chosa hen (Report on the Senkaku Islands Survey: Potential Development/Usage Survey) (Okinawa Development Agency, 1980).