Phreatic eruptions of Ruapehu: April 1975
Phreatic eruptions of Ruapehu: April 1975
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鲁阿佩胡火山喷发：1975 年 4 月
DOI：
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发表时间：
1979
期刊：
影响因子：
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通讯作者：
C. Hewson
中科院分区：
文献类型：
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作者：
I. Nairn;C. Wood;C. Hewson
1975年4月24日03时59分，新西兰北岛鲁阿佩胡火山口湖（Ruapehu Crater Lake）发生了一次大的火山喷发，在喷发前只有9分钟的火山-地震活动，但在喷发前两周就通过大地测量测量到了火山口的扩张。恶劣的天气阻碍了对火山喷发的观测。至少有1·6 + 106 m3的火山口湖水和湖底沉积物被喷出，最终湖泊水位下降超过8 m。热的弹道喷出物从喷口向上风向下降到1.6 km；细小的火山灰从一条向东南延伸至少115公里的窄烟羽中飘落下来。洪水冲下了鲁阿佩胡山顶的河谷，破坏了滑雪设施、桥梁和水电工程。由于喷发的时间，没有发生人员伤亡。固体喷出物主要由湖底沉积物、部分热变质为砂质岩相（bb0 ~ 750°c）的矿物组合以及少量碎屑质熔岩块组成。自持反应产汽…
Abstract A major phreatic eruption occurred in Ruapehu Crater Lake, North Island, New Zealand, at 1975 April 24d, 03h 59m, N.Z.S.T. Only nine minutes of volcanic-seismic activity preceded the eruption, but crater dilation had been measured by a geodetic survey two weeks earlier. Bad weather prevented observation of the eruption. At least 1· 6 + 106 m3 of Crater Lake water and lake floor deposits were ejected, final lake level falling by more than 8 m. Hot ballistic ejecta fell up to 1· 6 km upwind from the vent; fine ash fell from a narrow plume extending at least 115 km to south-east. Major floods passed down river valleys draining Ruapehu summit, damaging ski installations, bridges, and hydro-electric power scheme constructions. Because of the time of the eruption, no loss of life occurred. Solid ejecta consisted largely of lake floor deposits, some thermally metamorphosed to sanidinite facies (> 750°c) mineral assemblages, plus minor scoriaceous lava blocks. Steam production by self-sustained reaction ...