Nuées Ardentes of the 1968 Eruption of Mayon Volcano, Philippines
Nuées Ardentes of the 1968 Eruption of Mayon Volcano, Philippines
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1968 年菲律宾马荣火山喷发的 Nuées Ardentes
DOI：
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发表时间：
1969
期刊：
影响因子：
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通讯作者：
W. Melson
中科院分区：
文献类型：
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作者：
J. Moore;W. Melson
马荣火山，吕宋岛东南部，于1968年4月21日0900开始了一系列的爆炸性喷发，到5月15日，已经发生了100多次爆炸，至少6人死亡，大约100平方公里的土地被超过5厘米的空气灰，块状灰流和熔岩流所覆盖。从山顶火山口（海拔2460米）的爆炸将大量的火山灰和白炽块喷射到超过600米的高度，并产生了上升到3至10公里高度的含灰云。较粗的物质的回落形成了新的火山岩，这些火山岩反复地冲刷着火山锥四周的峡谷。一个新的ardente的速度范围从9到63米每秒。最大的努埃山脉向西南方向下降，最远可达距山顶7公里处。一个aa熔岩流也下降了3 1/2公里下来这个侧翼。nuées ardentes沉积火山碎屑流，其中包含大面包壳表面块平均约30厘米宽，但偶尔达到25米的最大尺寸。几天后，这些街区的内部仍然很热。火山碎屑流的周围是一个宽达2公里的烧焦区，但平均只有几百米，其中植被被烧焦和分裂，但上面只有一层薄薄的空气降落灰沉积。
Mayon Volcano, southeastern Luzon, began a series of explosive eruptions at 0900 April 21, 1968, and by May 15 more than 100 explosions had occurred, at least 6 people had been killed, and roughly 100 square km had been covered by more than 5 cm of airfall ash, blocky ash flows, and a lava flow. All material crupted was porphyritic augite-hypersthene andesite.Explosions from the summit crater (elevation 2460 m) ejected large quantities of ash and incandescent blocks to a height exceeding 600 m and produced ash-laden clouds which rose to heights of 3 to 10 km. Backfall of the coarser material fed nuées ardentes which repeatedly swept down ravines on all sides of the volcanic cone. The velocity of one nuée ardente ranged from 9 to 63 m per sec. The largest nuées descended to the southwest and reached as far as 7 km from the summit. An aa lava flow also descended 3 1/2 km down this flank.The nuées ardentes deposited pyroclastic flows that contained large breadcrust-surfaced blocks averaging about 30 cm across, but occasionally reaching 25 m in greatest dimension. These blocks were still very hot in their interiors several days later. Surrounding the pyroclastic flows is a seared zone as much as 2 km wide, but averaging a few hundred meters, in which vegetation is charred and splintered, but over which only a thin layer of airfall ash was deposited.