Source Mechanisms of Laboratory Earthquakes During Fault Nucleation and Formation
- Publication type:
- Journal article
- Metadata:
-
- Autoren
- Thomas King
- Sergio Vinciguerra
- Jodi Burgess
- Philip Benson
- Luca De Siena
- Autoren-URL
- https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=fis-test-1&SrcAuth=WosAPI&KeyUT=WOS:000654526100085&DestLinkType=FullRecord&DestApp=WOS_CPL
- DOI
- 10.1029/2020JB021059
- eISSN
- 2169-9356
- Externe Identifier
- Clarivate Analytics Document Solution ID: SI0NX
- ISSN
- 2169-9313
- Ausgabe der Veröffentlichung
- 5
- Zeitschrift
- JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
- Artikelnummer
- ARTN e2020JB021059
- Datum der Veröffentlichung
- 2021
- Status
- Published
- Titel
- Source Mechanisms of Laboratory Earthquakes During Fault Nucleation and Formation
- Sub types
- Article
- Ausgabe der Zeitschrift
- 126
Data source: Web of Science (Lite)
- Other metadata sources:
-
- Abstract
- <jats:title><jats:sc>A</jats:sc>bstract</jats:title><jats:p>Identifying deformation and pre‐failure mechanisms preceding faulting is key for fault mechanics and for interpreting precursors to fault rupture. This study presents the results of a new and robust derivation of first motion polarity focal mechanism solutions (FMS) applied to acoustic emission (AE). FMS are solved using a least squares minimization of the fit between projected polarity measurements and the deviatoric stress field induced by dilatational (T‐type), shearing (S‐type), and compressional (C‐type) sources. 4 × 10 cm cylindrical samples of Alzo Granite (AG, porosity <1%) and Darley Dale Sandstone (DDS, porosity ≈14%) underwent conventional triaxial tests in order to investigate the relationships between increasing confining pressure (5, 10, 20, and 40 MPa), deformation and failure mode, and role of microstructural features. Results highlight that S‐type events occur in very low numbers with poor spatial correlation to fault structure. Instead, deformation is driven by a complex interplay between compactant (C‐type) and dilatant (T‐type) regions of deformation. C‐type events are the earliest precursor related to crack nucleation and T‐type events mark new cracks opening, with the onset of fracture growth characterized by periodic cycles of coalescence. For AG a single sequence is able to lead to dynamic failure, while for DDS several cycles are needed for coalescence to take place due to the competition between dilatant and compactant deforming regions induced by multiple fracture nucleation sites. The occurrence of C‐ and S‐type events is also consistent with a quasi‐static premonitory phase, or foreshock, before a critical nucleation length allows the development of a planar localization.</jats:p>
- Autoren
- Thomas King
- Sergio Vinciguerra
- Jodi Burgess
- Philip Benson
- Luca De Siena
- DOI
- 10.1029/2020jb021059
- eISSN
- 2169-9356
- ISSN
- 2169-9313
- Ausgabe der Veröffentlichung
- 5
- Zeitschrift
- Journal of Geophysical Research: Solid Earth
- Sprache
- en
- Online publication date
- 2021
- Datum der Veröffentlichung
- 2021
- Status
- Published
- Herausgeber
- American Geophysical Union (AGU)
- Herausgeber URL
- http://dx.doi.org/10.1029/2020jb021059
- Datum der Datenerfassung
- 2023
- Titel
- Source Mechanisms of Laboratory Earthquakes During Fault Nucleation and Formation
- Ausgabe der Zeitschrift
- 126
Data source: Crossref
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