The influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting
Glacial environments exhibit temporally variable microseismicity. To investigate how microseismicity influences event detection, we implement two noise-adaptive digital power detectors to process seismic data from Taylor Glacier, Antarctica. We add scaled icequake waveforms to the original data stre...
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Cambridge University Press
2020
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ftdoajarticles:oai:doaj.org/article:ad5dff689f51418995f1fc1012beec58 2023-05-15T14:13:29+02:00 The influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting Chris G. Carr Joshua D. Carmichael Erin C. Pettit Martin Truffer 2020-10-01T00:00:00Z https://doi.org/10.1017/jog.2020.48 https://doaj.org/article/ad5dff689f51418995f1fc1012beec58 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0022143020000489/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2020.48 0022-1430 1727-5652 https://doaj.org/article/ad5dff689f51418995f1fc1012beec58 Journal of Glaciology, Vol 66, Pp 790-806 (2020) Antarctic glaciology seismicity seismology Environmental sciences GE1-350 Meteorology. Climatology QC851-999 article 2020 ftdoajarticles https://doi.org/10.1017/jog.2020.48 2023-03-12T01:30:57Z Glacial environments exhibit temporally variable microseismicity. To investigate how microseismicity influences event detection, we implement two noise-adaptive digital power detectors to process seismic data from Taylor Glacier, Antarctica. We add scaled icequake waveforms to the original data stream, run detectors on the hybrid data stream to estimate reliable detection magnitudes and compare analytical magnitudes predicted from an ice crack source model. We find that detection capability is influenced by environmental microseismicity for seismic events with source size comparable to thermal penetration depths. When event counts and minimum detectable event sizes change in the same direction (i.e. increase in event counts and minimum detectable event size), we interpret measured seismicity changes as ‘true’ seismicity changes rather than as changes in detection. Generally, one detector (two degree of freedom (2dof)) outperforms the other: it identifies more events, a more prominent summertime diurnal signal and maintains a higher detection capability. We conclude that real physical processes are responsible for the summertime diurnal inter-detector difference. One detector (3dof) identifies this process as environmental microseismicity; the other detector (2dof) identifies it as elevated waveform activity. Our analysis provides an example for minimizing detection biases and estimating source sizes when interpreting temporal seismicity patterns to better infer glacial seismogenic processes. Article in Journal/Newspaper Antarc* Antarctic Antarctica Journal of Glaciology Taylor Glacier Directory of Open Access Journals: DOAJ Articles Antarctic Taylor Glacier ENVELOPE(162.167,162.167,-77.733,-77.733) Journal of Glaciology 66 259 790 806 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Antarctic glaciology seismicity seismology Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
spellingShingle |
Antarctic glaciology seismicity seismology Environmental sciences GE1-350 Meteorology. Climatology QC851-999 Chris G. Carr Joshua D. Carmichael Erin C. Pettit Martin Truffer The influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting |
topic_facet |
Antarctic glaciology seismicity seismology Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
description |
Glacial environments exhibit temporally variable microseismicity. To investigate how microseismicity influences event detection, we implement two noise-adaptive digital power detectors to process seismic data from Taylor Glacier, Antarctica. We add scaled icequake waveforms to the original data stream, run detectors on the hybrid data stream to estimate reliable detection magnitudes and compare analytical magnitudes predicted from an ice crack source model. We find that detection capability is influenced by environmental microseismicity for seismic events with source size comparable to thermal penetration depths. When event counts and minimum detectable event sizes change in the same direction (i.e. increase in event counts and minimum detectable event size), we interpret measured seismicity changes as ‘true’ seismicity changes rather than as changes in detection. Generally, one detector (two degree of freedom (2dof)) outperforms the other: it identifies more events, a more prominent summertime diurnal signal and maintains a higher detection capability. We conclude that real physical processes are responsible for the summertime diurnal inter-detector difference. One detector (3dof) identifies this process as environmental microseismicity; the other detector (2dof) identifies it as elevated waveform activity. Our analysis provides an example for minimizing detection biases and estimating source sizes when interpreting temporal seismicity patterns to better infer glacial seismogenic processes. |
format |
Article in Journal/Newspaper |
author |
Chris G. Carr Joshua D. Carmichael Erin C. Pettit Martin Truffer |
author_facet |
Chris G. Carr Joshua D. Carmichael Erin C. Pettit Martin Truffer |
author_sort |
Chris G. Carr |
title |
The influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting |
title_short |
The influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting |
title_full |
The influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting |
title_fullStr |
The influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting |
title_full_unstemmed |
The influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting |
title_sort |
influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting |
publisher |
Cambridge University Press |
publishDate |
2020 |
url |
https://doi.org/10.1017/jog.2020.48 https://doaj.org/article/ad5dff689f51418995f1fc1012beec58 |
long_lat |
ENVELOPE(162.167,162.167,-77.733,-77.733) |
geographic |
Antarctic Taylor Glacier |
geographic_facet |
Antarctic Taylor Glacier |
genre |
Antarc* Antarctic Antarctica Journal of Glaciology Taylor Glacier |
genre_facet |
Antarc* Antarctic Antarctica Journal of Glaciology Taylor Glacier |
op_source |
Journal of Glaciology, Vol 66, Pp 790-806 (2020) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0022143020000489/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2020.48 0022-1430 1727-5652 https://doaj.org/article/ad5dff689f51418995f1fc1012beec58 |
op_doi |
https://doi.org/10.1017/jog.2020.48 |
container_title |
Journal of Glaciology |
container_volume |
66 |
container_issue |
259 |
container_start_page |
790 |
op_container_end_page |
806 |
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1766285959083589632 |