Brantut, N;
Mitchell, TM;
(2018)
Assessing the Efficiency of Thermal Pressurization Using Natural Pseudotachylyte-Bearing Rocks.
Geophysical Research Letters
, 45
(18)
pp. 9533-9541.
10.1029/2018GL078649.
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Abstract
The efficiency of thermal pressurization as a dynamic weakening mechanism relies on the thermal and hydraulic properties of the rocks forming the fault core. Here we assess the effectiveness of thermal pressurization by comparing predictions of temperature rise to field estimates based on pseudotachylyte-bearing rocks. We measure hydraulic and transport properties of a suite of fault rocks (a healed cataclasite, an unhealed breccia, and the intact parent rock) from the pseudotachylyte-bearing Gole Larghe fault in the Adamello batholith (Italy) and use them as inputs in numerical simulations of thermal pressurization. We find that the melting temperature can be reached only if damaged, unhealed rock properties are used. A tenfold increase in permeability or a fourfold increase in pore compressibility of the intact rock is required to achieve melting. Our results emphasize the importance of damage processes that strongly modify fault rock properties and dynamic weakening processes during earthquake propagation.
| Type: | Article |
|---|---|
| Title: | Assessing the Efficiency of Thermal Pressurization Using Natural Pseudotachylyte-Bearing Rocks |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1029/2018GL078649 |
| Publisher version: | https://doi.org/10.1029/2018GL078649 |
| Language: | English |
| Additional information: | This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| Keywords: | Thermal pressurization, pseudotachylyte, damage, dynamic weakening |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10057714 |
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