IN THE 1960s, while studying the volic history of Yellowstoional Park, BobChristiansen of the Uates Geological Survey became puzzled about something that,oddly, had not troubled anyone before: he couldn’t find the park’s volo. It had been knownfor a long time that Yellowstone was voli nature—that’s what ated for all itsgeysers and other steamy features—and the ohing about voloes is that they aregenerally pretty spicuous. But Christiansen couldn’t find the Yellowstone voloanywhere. In particular what he couldn’t find was a structure known as a caldera.
Most of us, whehink of voloes, think of the classie shapes of a Fuji orKilimanjaro, which are created wheing magma accumulates in a symmetrical mound.
These form remarkably quickly. In 1943, at Parí in Mexico, a farmer was startled tosee smoke rising from a pat his land. In one week he was the bemused owner of a efive hundred feet high. Within two years it had topped out at almost fourteen hundred……（内容加载失败！）
(ò﹏ò)
抱歉，章节内容不支持该浏览器显示～
【为了使用完整的阅读功能】
请考虑使用〔Chrome 谷歌浏览器〕、〔Safari 苹果浏览器〕或者〔Edge 微软浏览器〕等原生浏览器阅读！
谢谢!!!