Narrowband signals recorded near a moulin that are not moulin tremor: a cautionary short note
Geophysicists that deploy seismic sensors in ablation zones of glaciers and ice sheets to record glaciogenic signatures can confront recording challenges caused by instrument melt-out or tilt. These challenges often require installing sensors in boreholes to delay melt-out, or securing sensors to st...
Published in: | Annals of Glaciology |
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Language: | English |
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Cambridge University Press
2019
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Online Access: | https://doi.org/10.1017/aog.2019.23 https://doaj.org/article/78e6f7feefd243adaf10e24798c86c11 |
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ftdoajarticles:oai:doaj.org/article:78e6f7feefd243adaf10e24798c86c11 2023-05-15T13:29:36+02:00 Narrowband signals recorded near a moulin that are not moulin tremor: a cautionary short note Joshua D Carmichael 2019-09-01T00:00:00Z https://doi.org/10.1017/aog.2019.23 https://doaj.org/article/78e6f7feefd243adaf10e24798c86c11 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0260305519000235/type/journal_article https://doaj.org/toc/0260-3055 https://doaj.org/toc/1727-5644 doi:10.1017/aog.2019.23 0260-3055 1727-5644 https://doaj.org/article/78e6f7feefd243adaf10e24798c86c11 Annals of Glaciology, Vol 60, Pp 231-237 (2019) ice-sheet mass balance melt - surface seismicity seismology subglacial lakes Meteorology. Climatology QC851-999 article 2019 ftdoajarticles https://doi.org/10.1017/aog.2019.23 2023-03-12T01:31:55Z Geophysicists that deploy seismic sensors in ablation zones of glaciers and ice sheets to record glaciogenic signatures can confront recording challenges caused by instrument melt-out or tilt. These challenges often require installing sensors in boreholes to delay melt-out, or securing sensors to structures that improve coupling. We show that some of these structures that were buried near a moulin at a snow-free site in the ablation zone of the Western Greenland Ice Sheet resonated as they became exposed, and caused their geophones to record temporally evolving, narrowband signals that mimic features of glaciogenic sources like moulin tremor. We quantify these artifacts with a mechanical model that shows instruments undergo structural resonance as they melt-out, at exposure rates that we predict from an ablation model (RACMO). These models reproduce general spectral features in our data, and enable us to estimate what instrument exposure reduces ice-to-sensor coupling enough to prevent icequake detection. Last, we use our resonance data to quantitatively measure how narrowband signals that originate from either artificial or glaciogenic sources will reduce the ability of certain waveform detectors (correlators) to capture transient seismic events, even if sensors remain coupled. Article in Journal/Newspaper Annals of Glaciology Greenland Ice Sheet Directory of Open Access Journals: DOAJ Articles Greenland Annals of Glaciology 60 79 231 237 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
ice-sheet mass balance melt - surface seismicity seismology subglacial lakes Meteorology. Climatology QC851-999 |
spellingShingle |
ice-sheet mass balance melt - surface seismicity seismology subglacial lakes Meteorology. Climatology QC851-999 Joshua D Carmichael Narrowband signals recorded near a moulin that are not moulin tremor: a cautionary short note |
topic_facet |
ice-sheet mass balance melt - surface seismicity seismology subglacial lakes Meteorology. Climatology QC851-999 |
description |
Geophysicists that deploy seismic sensors in ablation zones of glaciers and ice sheets to record glaciogenic signatures can confront recording challenges caused by instrument melt-out or tilt. These challenges often require installing sensors in boreholes to delay melt-out, or securing sensors to structures that improve coupling. We show that some of these structures that were buried near a moulin at a snow-free site in the ablation zone of the Western Greenland Ice Sheet resonated as they became exposed, and caused their geophones to record temporally evolving, narrowband signals that mimic features of glaciogenic sources like moulin tremor. We quantify these artifacts with a mechanical model that shows instruments undergo structural resonance as they melt-out, at exposure rates that we predict from an ablation model (RACMO). These models reproduce general spectral features in our data, and enable us to estimate what instrument exposure reduces ice-to-sensor coupling enough to prevent icequake detection. Last, we use our resonance data to quantitatively measure how narrowband signals that originate from either artificial or glaciogenic sources will reduce the ability of certain waveform detectors (correlators) to capture transient seismic events, even if sensors remain coupled. |
format |
Article in Journal/Newspaper |
author |
Joshua D Carmichael |
author_facet |
Joshua D Carmichael |
author_sort |
Joshua D Carmichael |
title |
Narrowband signals recorded near a moulin that are not moulin tremor: a cautionary short note |
title_short |
Narrowband signals recorded near a moulin that are not moulin tremor: a cautionary short note |
title_full |
Narrowband signals recorded near a moulin that are not moulin tremor: a cautionary short note |
title_fullStr |
Narrowband signals recorded near a moulin that are not moulin tremor: a cautionary short note |
title_full_unstemmed |
Narrowband signals recorded near a moulin that are not moulin tremor: a cautionary short note |
title_sort |
narrowband signals recorded near a moulin that are not moulin tremor: a cautionary short note |
publisher |
Cambridge University Press |
publishDate |
2019 |
url |
https://doi.org/10.1017/aog.2019.23 https://doaj.org/article/78e6f7feefd243adaf10e24798c86c11 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Annals of Glaciology Greenland Ice Sheet |
genre_facet |
Annals of Glaciology Greenland Ice Sheet |
op_source |
Annals of Glaciology, Vol 60, Pp 231-237 (2019) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0260305519000235/type/journal_article https://doaj.org/toc/0260-3055 https://doaj.org/toc/1727-5644 doi:10.1017/aog.2019.23 0260-3055 1727-5644 https://doaj.org/article/78e6f7feefd243adaf10e24798c86c11 |
op_doi |
https://doi.org/10.1017/aog.2019.23 |
container_title |
Annals of Glaciology |
container_volume |
60 |
container_issue |
79 |
container_start_page |
231 |
op_container_end_page |
237 |
_version_ |
1766001433707020288 |