Microearthquakes at St. Augustine Volcano, Alaska, Triggered by Earth Tides
Microearthquake activity at St. Augustine volcano, located at the mouth of Cook Inlet in the Aleutian Islands, has been monitored since August 1970. Both before and after minor eruptive activity on 7 October 1971, numerous shallow-foci microearthquake swarms were recorded. Plots of the hourly freque...
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American Association for the Advancement of Science (AAAS)
1973
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Online Access: | http://dx.doi.org/10.1126/science.182.4110.386 https://www.science.org/doi/pdf/10.1126/science.182.4110.386 |
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craaas:10.1126/science.182.4110.386 2024-06-09T07:50:11+00:00 Microearthquakes at St. Augustine Volcano, Alaska, Triggered by Earth Tides Mauk, F. J. Kienle, J. 1973 http://dx.doi.org/10.1126/science.182.4110.386 https://www.science.org/doi/pdf/10.1126/science.182.4110.386 en eng American Association for the Advancement of Science (AAAS) Science volume 182, issue 4110, page 386-389 ISSN 0036-8075 1095-9203 journal-article 1973 craaas https://doi.org/10.1126/science.182.4110.386 2024-05-16T12:55:05Z Microearthquake activity at St. Augustine volcano, located at the mouth of Cook Inlet in the Aleutian Islands, has been monitored since August 1970. Both before and after minor eruptive activity on 7 October 1971, numerous shallow-foci microearthquake swarms were recorded. Plots of the hourly frequency of microearthquakes often show a diurnal peaking of activity. A cross correlation of this activity with the calculated magnitudes of tidal acceleration exhibited two prominent phase relationships. The first, and slightly more predominant, phase condition is a phase delay in the microearthquake activity of approximately 1 hour from the time of maximum tidal acceleration. This is thought to be a direct microearthquake-triggering effect caused by tidal stresses. The second is a phase delay in the microearthquake activity of approximately 5 hours, which correlates well with the time of maximum oceanic tidal loading. Correlation of the individual peaks of swarm activity with defined components of the tides suggests that it may be necessary for tidal stressing to have a preferential orientation in order to be an effective trigger of microearthquakes. Article in Journal/Newspaper Alaska Aleutian Islands AAAS Resource Center (American Association for the Advancement of Science) Science 182 4110 386 389 |
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Open Polar |
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AAAS Resource Center (American Association for the Advancement of Science) |
op_collection_id |
craaas |
language |
English |
description |
Microearthquake activity at St. Augustine volcano, located at the mouth of Cook Inlet in the Aleutian Islands, has been monitored since August 1970. Both before and after minor eruptive activity on 7 October 1971, numerous shallow-foci microearthquake swarms were recorded. Plots of the hourly frequency of microearthquakes often show a diurnal peaking of activity. A cross correlation of this activity with the calculated magnitudes of tidal acceleration exhibited two prominent phase relationships. The first, and slightly more predominant, phase condition is a phase delay in the microearthquake activity of approximately 1 hour from the time of maximum tidal acceleration. This is thought to be a direct microearthquake-triggering effect caused by tidal stresses. The second is a phase delay in the microearthquake activity of approximately 5 hours, which correlates well with the time of maximum oceanic tidal loading. Correlation of the individual peaks of swarm activity with defined components of the tides suggests that it may be necessary for tidal stressing to have a preferential orientation in order to be an effective trigger of microearthquakes. |
format |
Article in Journal/Newspaper |
author |
Mauk, F. J. Kienle, J. |
spellingShingle |
Mauk, F. J. Kienle, J. Microearthquakes at St. Augustine Volcano, Alaska, Triggered by Earth Tides |
author_facet |
Mauk, F. J. Kienle, J. |
author_sort |
Mauk, F. J. |
title |
Microearthquakes at St. Augustine Volcano, Alaska, Triggered by Earth Tides |
title_short |
Microearthquakes at St. Augustine Volcano, Alaska, Triggered by Earth Tides |
title_full |
Microearthquakes at St. Augustine Volcano, Alaska, Triggered by Earth Tides |
title_fullStr |
Microearthquakes at St. Augustine Volcano, Alaska, Triggered by Earth Tides |
title_full_unstemmed |
Microearthquakes at St. Augustine Volcano, Alaska, Triggered by Earth Tides |
title_sort |
microearthquakes at st. augustine volcano, alaska, triggered by earth tides |
publisher |
American Association for the Advancement of Science (AAAS) |
publishDate |
1973 |
url |
http://dx.doi.org/10.1126/science.182.4110.386 https://www.science.org/doi/pdf/10.1126/science.182.4110.386 |
genre |
Alaska Aleutian Islands |
genre_facet |
Alaska Aleutian Islands |
op_source |
Science volume 182, issue 4110, page 386-389 ISSN 0036-8075 1095-9203 |
op_doi |
https://doi.org/10.1126/science.182.4110.386 |
container_title |
Science |
container_volume |
182 |
container_issue |
4110 |
container_start_page |
386 |
op_container_end_page |
389 |
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1801383425804861440 |