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...
Published in: | Journal of Glaciology |
---|---|
Main Authors: | , , , |
Language: | unknown |
Published: |
2022
|
Subjects: | |
Online Access: | http://www.osti.gov/servlets/purl/1699461 https://www.osti.gov/biblio/1699461 https://doi.org/10.1017/jog.2020.48 |
id |
ftosti:oai:osti.gov:1699461 |
---|---|
record_format |
openpolar |
spelling |
ftosti:oai:osti.gov:1699461 2023-07-30T03:57:31+02:00 The influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting Carr, Chris G. Carmichael, Joshua D. Pettit, Erin C. Truffer, Martin 2022-05-30 application/pdf http://www.osti.gov/servlets/purl/1699461 https://www.osti.gov/biblio/1699461 https://doi.org/10.1017/jog.2020.48 unknown http://www.osti.gov/servlets/purl/1699461 https://www.osti.gov/biblio/1699461 https://doi.org/10.1017/jog.2020.48 doi:10.1017/jog.2020.48 54 ENVIRONMENTAL SCIENCES 2022 ftosti https://doi.org/10.1017/jog.2020.48 2023-07-11T09:51:58Z 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. Other/Unknown Material Antarc* Antarctica Taylor Glacier SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Taylor Glacier ENVELOPE(162.167,162.167,-77.733,-77.733) Journal of Glaciology 66 259 790 806 |
institution |
Open Polar |
collection |
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
54 ENVIRONMENTAL SCIENCES |
spellingShingle |
54 ENVIRONMENTAL SCIENCES Carr, Chris G. Carmichael, Joshua D. Pettit, Erin C. Truffer, Martin The influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting |
topic_facet |
54 ENVIRONMENTAL SCIENCES |
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. |
author |
Carr, Chris G. Carmichael, Joshua D. Pettit, Erin C. Truffer, Martin |
author_facet |
Carr, Chris G. Carmichael, Joshua D. Pettit, Erin C. Truffer, Martin |
author_sort |
Carr, Chris G. |
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 |
publishDate |
2022 |
url |
http://www.osti.gov/servlets/purl/1699461 https://www.osti.gov/biblio/1699461 https://doi.org/10.1017/jog.2020.48 |
long_lat |
ENVELOPE(162.167,162.167,-77.733,-77.733) |
geographic |
Taylor Glacier |
geographic_facet |
Taylor Glacier |
genre |
Antarc* Antarctica Taylor Glacier |
genre_facet |
Antarc* Antarctica Taylor Glacier |
op_relation |
http://www.osti.gov/servlets/purl/1699461 https://www.osti.gov/biblio/1699461 https://doi.org/10.1017/jog.2020.48 doi:10.1017/jog.2020.48 |
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 |
_version_ |
1772817841159929856 |