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

DOI: 10.1038/s41467-022-33855-z

Authors: Alexis Cartwright-Taylor (University of Edinburgh) , Maria-Daphne Mangriotis (University of Edinburgh) , Ian G. Main (University of Edinburgh) , Ian B. Butler (University of Edinburgh) , Florian Fusseis (University of Edinburgh) , Martin Ling (Independent Electronics Developer) , Edward Andò (École Polytechnique Fédérale de Lausanne (EPFL)) , Andrew Curtis (University of Edinburgh) , Andrew F. Bell (University of Edinburgh) , Alyssa Crippen (University of Edinburgh) , Roberto E. Rizzo (University of Edinburgh; University of Florence) , Sina Marti (University of Edinburgh) , Derek D. V. Leung (University of Edinburgh) , Oxana V. Magdysyuk (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Communications , VOL 13

State: Published (Approved)
Published: October 2022
Diamond Proposal Number(s): 22517

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.

Journal Keywords: Mechanical properties; Natural hazards; Seismology; Tectonics

Diamond Keywords: Earthquakes

Subject Areas: Earth Science, Engineering


Instruments: I12-JEEP: Joint Engineering, Environmental and Processing

Added On: 24/10/2022 10:41

Documents:
s41467-022-33855-z.pdf

Discipline Tags:

Earth Sciences & Environment Natural disaster Materials Engineering & Processes Engineering & Technology Geology Geophysics

Technical Tags:

Imaging Tomography