Characterization of seismicity from different glacial bed types: machine learning classification of laboratory stick-slip acoustic emissions

Subglacial seismicity presents the opportunity to monitor inaccessible glacial beds at the epicentral location and time. Glaciers can be underlain by rock or till, a first order control on bed mechanics. Velocity-weakening, necessary for unstable slip, has been shown for each bed type, but is much s...

Full description

Bibliographic Details
Main Authors: Seth Saltiel, Nathan Groebner, Theresa Sawi, Christine McCarthy
Format: Article
Language:English
Published: Cambridge University Press
Series:Annals of Glaciology
Subjects:
Online Access:https://www.cambridge.org/core/product/identifier/S0260305524000119/type/journal_article
_version_ 1797218205230432256
author Seth Saltiel
Nathan Groebner
Theresa Sawi
Christine McCarthy
author_facet Seth Saltiel
Nathan Groebner
Theresa Sawi
Christine McCarthy
author_sort Seth Saltiel
collection DOAJ
description Subglacial seismicity presents the opportunity to monitor inaccessible glacial beds at the epicentral location and time. Glaciers can be underlain by rock or till, a first order control on bed mechanics. Velocity-weakening, necessary for unstable slip, has been shown for each bed type, but is much stronger and evolves over more than an order of magnitude longer distances for till beds. Utilizing a de-stiffened double direct shear apparatus, we found conditions for instability at freezing temperatures and high slip rates for both bed types. During stick–slip stress-drops, we recorded acoustic emissions with piezoelectric transducers frozen into the ice. The two populations of event waveforms appear visually similar and overlap in their statistical features. We implemented a suite of supervised machine learning algorithms to classify the bed type of recorded waveforms and spectra, with prediction accuracy between 65–80%. The Random Forest Classifier is interpretable, showing the importance of initial oscillation peaks and higher frequency energy. Till beds have generally higher friction and resulting stress-drops, with more impulsive first arrivals and more high frequency content compared to rock emissions, but rock beds can produce many till-like events. Seismic signatures could enhance interpretation of bed conditions and mechanics from subglacial seismicity.
first_indexed 2024-04-24T12:14:03Z
format Article
id doaj.art-dc86d0774e744f8e9ea2f5f0ebbdfc6b
institution Directory Open Access Journal
issn 0260-3055
1727-5644
language English
last_indexed 2024-04-24T12:14:03Z
publisher Cambridge University Press
record_format Article
series Annals of Glaciology
spelling doaj.art-dc86d0774e744f8e9ea2f5f0ebbdfc6b2024-04-08T08:49:59ZengCambridge University PressAnnals of Glaciology0260-30551727-56441810.1017/aog.2024.11Characterization of seismicity from different glacial bed types: machine learning classification of laboratory stick-slip acoustic emissionsSeth Saltiel0https://orcid.org/0000-0002-8058-6894Nathan Groebner1Theresa Sawi2Christine McCarthy3Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, USADepartment of Research, Strabo Analytics, Inc, New York, NY, USALamont-Doherty Earth Observatory, Columbia University of New York, NY, USALamont-Doherty Earth Observatory, Columbia University of New York, NY, USASubglacial seismicity presents the opportunity to monitor inaccessible glacial beds at the epicentral location and time. Glaciers can be underlain by rock or till, a first order control on bed mechanics. Velocity-weakening, necessary for unstable slip, has been shown for each bed type, but is much stronger and evolves over more than an order of magnitude longer distances for till beds. Utilizing a de-stiffened double direct shear apparatus, we found conditions for instability at freezing temperatures and high slip rates for both bed types. During stick–slip stress-drops, we recorded acoustic emissions with piezoelectric transducers frozen into the ice. The two populations of event waveforms appear visually similar and overlap in their statistical features. We implemented a suite of supervised machine learning algorithms to classify the bed type of recorded waveforms and spectra, with prediction accuracy between 65–80%. The Random Forest Classifier is interpretable, showing the importance of initial oscillation peaks and higher frequency energy. Till beds have generally higher friction and resulting stress-drops, with more impulsive first arrivals and more high frequency content compared to rock emissions, but rock beds can produce many till-like events. Seismic signatures could enhance interpretation of bed conditions and mechanics from subglacial seismicity.https://www.cambridge.org/core/product/identifier/S0260305524000119/type/journal_articleSeismicitysubglacial exploration geophysicssubglacial processesseismologyglacier geophysics
spellingShingle Seth Saltiel
Nathan Groebner
Theresa Sawi
Christine McCarthy
Characterization of seismicity from different glacial bed types: machine learning classification of laboratory stick-slip acoustic emissions
Annals of Glaciology
Seismicity
subglacial exploration geophysics
subglacial processes
seismology
glacier geophysics
title Characterization of seismicity from different glacial bed types: machine learning classification of laboratory stick-slip acoustic emissions
title_full Characterization of seismicity from different glacial bed types: machine learning classification of laboratory stick-slip acoustic emissions
title_fullStr Characterization of seismicity from different glacial bed types: machine learning classification of laboratory stick-slip acoustic emissions
title_full_unstemmed Characterization of seismicity from different glacial bed types: machine learning classification of laboratory stick-slip acoustic emissions
title_short Characterization of seismicity from different glacial bed types: machine learning classification of laboratory stick-slip acoustic emissions
title_sort characterization of seismicity from different glacial bed types machine learning classification of laboratory stick slip acoustic emissions
topic Seismicity
subglacial exploration geophysics
subglacial processes
seismology
glacier geophysics
url https://www.cambridge.org/core/product/identifier/S0260305524000119/type/journal_article
work_keys_str_mv AT sethsaltiel characterizationofseismicityfromdifferentglacialbedtypesmachinelearningclassificationoflaboratorystickslipacousticemissions
AT nathangroebner characterizationofseismicityfromdifferentglacialbedtypesmachinelearningclassificationoflaboratorystickslipacousticemissions
AT theresasawi characterizationofseismicityfromdifferentglacialbedtypesmachinelearningclassificationoflaboratorystickslipacousticemissions
AT christinemccarthy characterizationofseismicityfromdifferentglacialbedtypesmachinelearningclassificationoflaboratorystickslipacousticemissions