Jeju uprising to Jeju from Busan and deploying police companies, each 1,700 strong, from the southern provinces of the mainland. The guerrillas retreated to their bases in the forests and caves around Hallasan, an extinct volcano and the highest mountain in South Korea. On April 29, the Korean, non-military, governor of Jeju province abandoned his post, defected, and joined the guerrillas. This caused many police officers, disillusioned by the atrocities they were ordered to commit against their own, to do the same. In response, U.S. military provincial governor William F. Dean ordered a purge of SKLP sympathizers from the ranks of the
Aluchin (volcano) soil on the lava flows and the growth of trees on them. This makes Aluchin one of the few continental Asian volcanoes with activity during the Holocene. The formation of the Alpha cone was characterized by an alternation of explosive and effusive activity. The Anyuy volcano lies farther north. Aluchin (volcano) Aluchin is a volcano along the Aluchin River in the Chukotka of Russia. The volcano was discovered in 1956–1957 by G.K. Kleshchev. The volcano is formed by three cones, named Alpha, Beta and Gamma, which occur along a fissure. Alpha, the main cone, formed within a river valley. It