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
Shield volcano system. Venus also has over 150 shield volcanoes which are much flatter, with a larger surface area than those found on Earth, some having a diameter of more than . Although the majority of these are long extinct it has been suggested, from observations by the Venus Express spacecraft, that many may still be active. Shield volcano A shield volcano is a type of volcano usually composed almost entirely of fluid lava flows. It is named for its low profile, resembling a warrior's shield lying on the ground. This is caused by the highly fluid (low viscosity) lava erupted, which