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Mount Pinatubo () is an active stratovolcano in the Cabusilan Mountains on the island of Luzon, near the tripoint of the Philippine provinces of Zambales, Tarlac, and Pampanga.〔(【引用サイトリンク】title=Tarlac map )〕〔("Report of the Philippine Commission to the President, 1901 Vol. III" ), pg. 141. Government Printing Office, Washington, 1901.〕 Before the volcanic activities of 1991, its eruptive history was unknown to most people. It was heavily eroded, inconspicuous and obscured from view. It was covered with dense forest which supported a population of several thousand indigenous people, the Aetas, who fled to the mountains during the Spanish conquest of the Philippines. The volcano's Plinian / Ultra-Plinian eruption on 15 June 1991 produced the second largest terrestrial eruption of the 20th century after the 1912 eruption of Novarupta in the Alaska Peninsula.〔(【引用サイトリンク】url=http://pubs.usgs.gov/fs/1997/fs113-97/ )〕 Complicating the eruption was the arrival of Typhoon Yunya (Diding), bringing a lethal mix of ash and rain to areas surrounding the volcano. Successful predictions at the onset of the climactic eruption led to the evacuation of tens of thousands of people from the surrounding areas, saving many lives, but the surrounding areas were severely damaged by pyroclastic flows, ash deposits, and subsequently, by the lahars caused by rainwaters re-mobilizing earlier volcanic deposits causing extensive destruction to infrastructure and changing the river systems months to years after the eruption.〔 The effects of the eruption were felt worldwide. It ejected roughly or of magma, and , bringing vast quantities of minerals and metals to the surface environment. It injected more particulate into the stratosphere than any eruption since Krakatoa in 1883. Over the following months, the aerosols formed a global layer of sulfuric acid haze. Global temperatures dropped by about in the years 1991-93, and ozone depletion temporarily increased substantially.〔(【引用サイトリンク】title=Mt. Pinatubo's cloud shades global climate )〕 ==Overview of the area== The volcano is northwest of Manila, the capital of the Philippines. Near Mount Pinatubo, the United States maintained two large military bases in the region. The U.S. Naval Base Subic Bay was south of Pinatubo, and the extent of Clark Air Base was just east of the volcano's summit.〔Tactical Pilotage Chart, Sheet K-11B, Defense Mapping Agency, Department of Defense, 1982.〕 The volcano's location on Luzon is in close proximity to about 6 million people.〔(Philippine Census )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Mount Pinatubo」の詳細全文を読む スポンサード リンク
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