A study of the seismic and volcanic activity of Mount Erebus, Antarctica, 1981-1982
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 group...
Main Authors: | , , , , |
---|---|
Format: | Report |
Language: | English |
Published: |
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
1983
|
Subjects: | |
Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1465 http://id.nii.ac.jp/1291/00001465/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1465&item_no=1&attribute_id=18&file_no=1 |
id |
ftnipr:oai:nipr.repo.nii.ac.jp:00001465 |
---|---|
record_format |
openpolar |
spelling |
ftnipr:oai:nipr.repo.nii.ac.jp:00001465 2023-05-15T13:47:59+02:00 A study of the seismic and volcanic activity of Mount Erebus, Antarctica, 1981-1982 Kazuo Shibuya Megumi Baba Juergen Kienle Ray R. Dibble Philip R. Kyle 1983-10 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1465 http://id.nii.ac.jp/1291/00001465/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1465&item_no=1&attribute_id=18&file_no=1 en eng 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 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1465 http://id.nii.ac.jp/1291/00001465/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 28, 54-66(1983-10) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1465&item_no=1&attribute_id=18&file_no=1 Departmental Bulletin Paper P(論文) 1983 ftnipr 2022-11-12T19:42:17Z 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. Report Antarc* Antarctica Memoirs of National Institute of Polar Research Polar Research National Institute of Polar Research Repository, Japan Lava Lake ENVELOPE(-128.996,-128.996,55.046,55.046) Mount Erebus ENVELOPE(167.167,167.167,-77.533,-77.533) |
institution |
Open Polar |
collection |
National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
description |
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. |
format |
Report |
author |
Kazuo Shibuya Megumi Baba Juergen Kienle Ray R. Dibble Philip R. Kyle |
spellingShingle |
Kazuo Shibuya Megumi Baba Juergen Kienle Ray R. Dibble Philip R. Kyle A study of the seismic and volcanic activity of Mount Erebus, Antarctica, 1981-1982 |
author_facet |
Kazuo Shibuya Megumi Baba Juergen Kienle Ray R. Dibble Philip R. Kyle |
author_sort |
Kazuo Shibuya |
title |
A study of the seismic and volcanic activity of Mount Erebus, Antarctica, 1981-1982 |
title_short |
A study of the seismic and volcanic activity of Mount Erebus, Antarctica, 1981-1982 |
title_full |
A study of the seismic and volcanic activity of Mount Erebus, Antarctica, 1981-1982 |
title_fullStr |
A study of the seismic and volcanic activity of Mount Erebus, Antarctica, 1981-1982 |
title_full_unstemmed |
A study of the seismic and volcanic activity of Mount Erebus, Antarctica, 1981-1982 |
title_sort |
study of the seismic and volcanic activity of mount erebus, antarctica, 1981-1982 |
publisher |
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 |
publishDate |
1983 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1465 http://id.nii.ac.jp/1291/00001465/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1465&item_no=1&attribute_id=18&file_no=1 |
long_lat |
ENVELOPE(-128.996,-128.996,55.046,55.046) ENVELOPE(167.167,167.167,-77.533,-77.533) |
geographic |
Lava Lake Mount Erebus |
geographic_facet |
Lava Lake Mount Erebus |
genre |
Antarc* Antarctica Memoirs of National Institute of Polar Research Polar Research |
genre_facet |
Antarc* Antarctica Memoirs of National Institute of Polar Research Polar Research |
op_relation |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1465 http://id.nii.ac.jp/1291/00001465/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 28, 54-66(1983-10) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1465&item_no=1&attribute_id=18&file_no=1 |
_version_ |
1766248276507492352 |