JAN MAYEN, an Arctic island between Greenland and the north of Norway, about 7I° N., 8° W. It is 34 m. long and 9 m. in greatest breadth, and is divided into two parts by a low, narrow isthmus. The island is of quaternary volcanic formation and mountainous, the highest summit being the extinct volcano of Beerenberg (8,094 ft.). Eruptions of ashes and steam have been observed. Glaciers are fully developed. Henry Hudson discovered the island in 1607 and called it Hudson's Tutches. Thereafter it was several times observed by navigators who successively claimed its discovery and renamed it. Thus, in 1611 or 1612 Hull whalers named it Trinity Island; in 1612 Jean Vrolicq, a French whaler, called it Ile de Richelieu; and in 1614 Joris Carolus, mate of the Dutch ship of Captain Jan May named it Joris Eylandt.
The climate is cold and foggy. There is a little tundra and a few foxes exist on the island. The island has been frequently visited by explorers, sealers, trappers and whalers ; and an Austrian obser vatory was maintained here for a year in 1882-83. J. M. Wordie and P. L. Mercanton completed the exploration in 1921. A Nor wegian observatory, with wireless communication, has been work ing since 1921. Jan Mayen was annexed to Norway, May 8, 1929.