Influence of high-latitude geomagnetic pulsations on recordings of broadband force-balanced seismic sensors
Seismic broadband sensors with electromagnetic feedback are sensitive to variations of surrounding magnetic field, including variations of geomagnetic field. Usually, the influence of the geomagnetic field on recordings of such seismometers is ignored. It might be justified for seismic observations...
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ftcopernicus:oai:publications.copernicus.org:gi14315 2023-05-15T17:42:41+02:00 Influence of high-latitude geomagnetic pulsations on recordings of broadband force-balanced seismic sensors Kozlovskaya, E. Kozlovsky, A. 2018-09-27 application/pdf https://doi.org/10.5194/gi-1-85-2012 https://gi.copernicus.org/articles/1/85/2012/ eng eng doi:10.5194/gi-1-85-2012 https://gi.copernicus.org/articles/1/85/2012/ eISSN: 2193-0864 Text 2018 ftcopernicus https://doi.org/10.5194/gi-1-85-2012 2020-07-20T16:25:45Z Seismic broadband sensors with electromagnetic feedback are sensitive to variations of surrounding magnetic field, including variations of geomagnetic field. Usually, the influence of the geomagnetic field on recordings of such seismometers is ignored. It might be justified for seismic observations at middle and low latitudes. The problem is of high importance, however, for observations in Polar Regions (above 60° geomagnetic latitude), where magnitudes of natural magnetic disturbances may be two or even three orders larger. In our study we investigate the effect of ultra-low frequency (ULF) magnetic disturbances, known as geomagnetic pulsations, on the STS-2 seismic broadband sensors. The pulsations have their sources and, respectively, maximal amplitudes in the region of the auroral ovals, which surround the magnetic poles in both hemispheres at geomagnetic latitude (GMLAT) between 60° and 80°. To investigate sensitivity of the STS-2 seismometer to geomagnetic pulsations, we compared the recordings of permanent seismic stations in northern Finland to the data of the magnetometers of the IMAGE network located in the same area. Our results show that temporary variations of magnetic field with periods of 40–150 s corresponding to regular Pc4 and irregular Pi2 pulsations are seen very well in recordings of the STS-2 seismometers. Therefore, these pulsations may create a serious problem for interpretation of seismic observations in the vicinity of the auroral oval. Moreover, the shape of Pi2 magnetic disturbances and their periods resemble the waveforms of glacial seismic events reported originally by Ekström (2003). The problem may be treated, however, if combined analysis of recordings of co-located seismic and magnetic instruments is used. Text Northern Finland Copernicus Publications: E-Journals Geoscientific Instrumentation, Methods and Data Systems 1 2 85 101 |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
Seismic broadband sensors with electromagnetic feedback are sensitive to variations of surrounding magnetic field, including variations of geomagnetic field. Usually, the influence of the geomagnetic field on recordings of such seismometers is ignored. It might be justified for seismic observations at middle and low latitudes. The problem is of high importance, however, for observations in Polar Regions (above 60° geomagnetic latitude), where magnitudes of natural magnetic disturbances may be two or even three orders larger. In our study we investigate the effect of ultra-low frequency (ULF) magnetic disturbances, known as geomagnetic pulsations, on the STS-2 seismic broadband sensors. The pulsations have their sources and, respectively, maximal amplitudes in the region of the auroral ovals, which surround the magnetic poles in both hemispheres at geomagnetic latitude (GMLAT) between 60° and 80°. To investigate sensitivity of the STS-2 seismometer to geomagnetic pulsations, we compared the recordings of permanent seismic stations in northern Finland to the data of the magnetometers of the IMAGE network located in the same area. Our results show that temporary variations of magnetic field with periods of 40–150 s corresponding to regular Pc4 and irregular Pi2 pulsations are seen very well in recordings of the STS-2 seismometers. Therefore, these pulsations may create a serious problem for interpretation of seismic observations in the vicinity of the auroral oval. Moreover, the shape of Pi2 magnetic disturbances and their periods resemble the waveforms of glacial seismic events reported originally by Ekström (2003). The problem may be treated, however, if combined analysis of recordings of co-located seismic and magnetic instruments is used. |
format |
Text |
author |
Kozlovskaya, E. Kozlovsky, A. |
spellingShingle |
Kozlovskaya, E. Kozlovsky, A. Influence of high-latitude geomagnetic pulsations on recordings of broadband force-balanced seismic sensors |
author_facet |
Kozlovskaya, E. Kozlovsky, A. |
author_sort |
Kozlovskaya, E. |
title |
Influence of high-latitude geomagnetic pulsations on recordings of broadband force-balanced seismic sensors |
title_short |
Influence of high-latitude geomagnetic pulsations on recordings of broadband force-balanced seismic sensors |
title_full |
Influence of high-latitude geomagnetic pulsations on recordings of broadband force-balanced seismic sensors |
title_fullStr |
Influence of high-latitude geomagnetic pulsations on recordings of broadband force-balanced seismic sensors |
title_full_unstemmed |
Influence of high-latitude geomagnetic pulsations on recordings of broadband force-balanced seismic sensors |
title_sort |
influence of high-latitude geomagnetic pulsations on recordings of broadband force-balanced seismic sensors |
publishDate |
2018 |
url |
https://doi.org/10.5194/gi-1-85-2012 https://gi.copernicus.org/articles/1/85/2012/ |
genre |
Northern Finland |
genre_facet |
Northern Finland |
op_source |
eISSN: 2193-0864 |
op_relation |
doi:10.5194/gi-1-85-2012 https://gi.copernicus.org/articles/1/85/2012/ |
op_doi |
https://doi.org/10.5194/gi-1-85-2012 |
container_title |
Geoscientific Instrumentation, Methods and Data Systems |
container_volume |
1 |
container_issue |
2 |
container_start_page |
85 |
op_container_end_page |
101 |
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1766144579952705536 |