火山是怎么形成的?
How Volcanoes Form
In 1980 in Washington, after 123 years of hibernation, Mount St.Helens erupted. The blast destroyed and scorched 230 square miles (370 squarekilometers) of forest within minutes. The eruption released an avalanche of hotash, gas, steam, and rocks that mowed down giant trees up to 15 miles (24kilometers) away.
When magma finds a way to escape from beneath the earth's surface,it creates a volcano.
Volcanoes erupt in different ways. Some, like Mount St. Helens,explode. Explosive eruptions are so powerful, they can shoot particles 20 milesup (32 kilometers), hurl 8-ton boulders more than a half mile(0.8 kilometers) away, and cause massive landslides. Explosive eruptionsalso create an avalanche of hot volcanic debris, ash, and gas that bulldozeseverything in its path. Explosive volcanoes cause most of the volcano-relatedfatalities.
Volcanoes, like Mauna Loa in Hawaii, are effusive. Rather than aviolent explosion, lava pours or flows out. Fatalities from effusive volcanoesare rare because people can usually outrun the lava. However, some people gettoo close or become trapped with no escape. The flowing lava burns, melts, anddestroys everything it touches including farms, houses, and roads.
A volcanic eruption forever changes the landscape. Thoughvolcanoes destroy, they also create mountains, islands, and, eventually,incredibly fertile land.
Carpet of Ash
Volcanic eruptions can cause damage hundreds of miles away.Volcanic ash causes airplane engines to fail, destroys crops, contaminateswater, and damages electronics and machinery. The ash carpets the ground,burying everything, sometimes even causing buildings to collapse. Mount St.Helens produced more than 490 tons of ash that fell over a 22,000 square mile(56,980 square kilometer) area and caused problems in cities 370 miles (600kilometers) away.
如果你希望了解我们更多的节目,请关注微信公号【荒野苏州】
拓展孩子的词汇量
提高孩子的表达能力
本专辑原创音频版权归“荒野苏州”所有,未经授权许可,严禁用于其他平台或商业用途!