Item type |
紀要論文(ELS) / Departmental Bulletin Paper(1) |
公開日 |
1983-10-01 |
タイトル |
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言語 |
en |
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タイトル |
A study of the seismic and volcanic activity of Mount Erebus, Antarctica, 1981-1982 |
言語 |
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言語 |
eng |
資源タイプ |
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資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
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資源タイプ |
departmental bulletin paper |
ページ属性 |
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内容記述タイプ |
Other |
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内容記述 |
P(論文) |
著者名(英) |
Shibuya, Kazuo
Baba, Megumi
Kienle, Juergen
Dibble, Ray R.
Kyle, Philip R.
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著者所属(英) |
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en |
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National Institute of Polar Research/Department of Earth Science, Faculty of Science, Chiba University/Geophysical Institute, University of Alaska/Department of Geology, Victoria University/Department of Geoscience, New Mexico Institute of Mining and Technology |
抄録(英) |
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内容記述タイプ |
Other |
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内容記述 |
In order to monitor the long-term seismicity of Mount Erebus, Antarctica, seismic observations have been made since 1980 using radio-telemetered and local networks. The observations in the 1981-1982 field season enabled us to determine to hypocenters of 162 local events. The hypocenters can be grouped into two sets, group I with focal depths ranging from the elevation of the summit to sea level, and group II with depths ranging from sea level to 15km. The epicenters of group I earthquakes are concentrated 1 to 2.5km north-northeast of the summit crater, and have a nearly vertical focal depth distribution. They are accompanied by infrasonic signals of two distinct waveform types, which allowed the earthquakes to be classified into two sub-sets, called arbitrarily α-and β-type events. There are about twice as many α-type events than β-Type events. The epicenters of the deeper α-type events are more tightly clustered than those of the shallower β-type events. A comparison of the arrival times of the infrasonic signals with those of the seismic signals at the summit station indicates that infrasonic signals associated with α-type events may be shock waves traveling at a sound speed of around Mach 2. The shock waves may be generated at the surface of the lava lake that occupies an inner summit crater. The different character of α-and β-type infrasonic signals is probably the result of different partitioning of acoustic and seismic energies for the shallower β-type events and the somewhat deeper α-type events. The number of group Ii earthquakes is smaller by one order of magnitude compared to group I earthquakes. The hypocenters are scattered more widely and form an elongated pattern that is slightly inclined to a northeast. Group II earthquakes are not accompanied by infrasonic signals but are characterized by higher-frequency seismic signals at all stations. |
雑誌書誌ID |
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収録物識別子タイプ |
NCID |
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収録物識別子 |
AA00733561 |
書誌情報 |
Memoirs of National Institute of Polar Research. Special issue
巻 28,
p. 54-66,
発行日 1983-10
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