Catastrophic failure in brittle, porous materials initiates when smaller-scale fractures localise along an emergent fault zone in a transition from stable crack growth to dynamic rupture. Due to the rapid nature of this critical transition, the precise micro-mechanisms involved are poorly understood and difficult to image directly. Here, we observe these micro-mechanisms directly by controlling the microcracking rate to slow down the transition in a unique rock deformation experiment that combines acoustic monitoring (sound) with contemporaneous in-situ x-ray imaging (vision) of the microstructure. We find seismic amplitude is not always correlated with local imaged strain; large local strain often occurs with small acoustic emissions, and vice versa. Local strain is predominantly aseismic, explained in part by grain/crack rotation along an emergent shear zone, and the shear fracture energy calculated from local dilation and shear strain on the fault is half of that inferred from the bulk deformation.

Seismic events miss important kinematically governed grain scale mechanisms during shear failure of porous rock / Cartwright-Taylor, Alexis; Mangriotis, Maria-Daphne; Main, Ian G; Butler, Ian B; Fusseis, Florian; Ling, Martin; Andò, Edward; Curtis, Andrew; Bell, Andrew F; Crippen, Alyssa; Rizzo, Roberto E; Marti, Sina; Leung, Derek D V; Magdysyuk, Oxana V. - In: NATURE COMMUNICATIONS. - ISSN 2041-1723. - ELETTRONICO. - 13:(2022), pp. 0-0. [10.1038/s41467-022-33855-z]

Seismic events miss important kinematically governed grain scale mechanisms during shear failure of porous rock

Rizzo, Roberto E
Investigation
;
2022

Abstract

Catastrophic failure in brittle, porous materials initiates when smaller-scale fractures localise along an emergent fault zone in a transition from stable crack growth to dynamic rupture. Due to the rapid nature of this critical transition, the precise micro-mechanisms involved are poorly understood and difficult to image directly. Here, we observe these micro-mechanisms directly by controlling the microcracking rate to slow down the transition in a unique rock deformation experiment that combines acoustic monitoring (sound) with contemporaneous in-situ x-ray imaging (vision) of the microstructure. We find seismic amplitude is not always correlated with local imaged strain; large local strain often occurs with small acoustic emissions, and vice versa. Local strain is predominantly aseismic, explained in part by grain/crack rotation along an emergent shear zone, and the shear fracture energy calculated from local dilation and shear strain on the fault is half of that inferred from the bulk deformation.
13
0
0
Cartwright-Taylor, Alexis; Mangriotis, Maria-Daphne; Main, Ian G; Butler, Ian B; Fusseis, Florian; Ling, Martin; Andò, Edward; Curtis, Andrew; Bell, Andrew F; Crippen, Alyssa; Rizzo, Roberto E; Marti, Sina; Leung, Derek D V; Magdysyuk, Oxana V
File in questo prodotto:
File Dimensione Formato  
s41467-022-33855-z.pdf

accesso aperto

Tipologia: Pdf editoriale (Version of record)
Licenza: Open Access
Dimensione 2.44 MB
Formato Adobe PDF
2.44 MB Adobe PDF Visualizza/Apri

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2158/1285975
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact