Rock Slab Growing at Mt. St. Helens Volcano
影像提供: Dan Dzurisin, Cascades Volcano Observatory, USGS
Explanation:
A new rock slab is growing at more than one meter a day on the Mt. St. Helens volcano in Washington, USA. The rock slab, growing since last November, now extends about 100 meters out from one of the volcano's craters. A recently made time lapse movie shows the rock slab growing. Pictured above, a helicopter examines the steaming hot rock slab late last month. Mt. St. Helens underwent a spectacular eruption in 1980 but has been undergoing a comparatively serene eruption since 2004 September. A new volcanic dome has been building which is now about 100 meters above the 1980s dome. The rock slab is visible from the Johnston Ridge Observatory on the erupting volcano.
說明:
位在美國．華盛頓州的聖海倫火山 (Mt. St. Helens)，現在出現了一塊每天增長超過一公尺的新石板。這片石板從去年的11月開始增高，現在從其中一個火山口向上伸出的高度已超過一百公尺；最近剛完成了一則時序動畫呈現這片石板成長的情形。上面這幅在上個拍攝影像裡，一架直昇機正在檢視這片熾熱冒煙的石板。聖海倫火山在1980年發生過壯觀的爆發，而在2004年9月之後，就不斷發生小規模的爆發。一個新的火山丘正在形成中，它的高度比1980年代的火山丘大約要高出一百公尺。這片位在爆發火山上的石板，從詹森脊觀測站 (Johnson Ridge Observatory)就可以看見。
資料來源: Scientific American
Department of Physics, NCKU
