[S-CG45] Science of slow-to-fast earthquakes

[SCG45-54] Moment-duration scaling of experimental tremors at in-situ pressure and temperature conditions

Petr Zverev^4,2, Julien Gasc², Loic Labrousse⁴, Timm John⁵, Joern Kummerow⁵, Oliver Plümper⁶, *Alexandre SCHUBNEL^1,2,3, Satoshi Ide³ (1.CNRS , 2.ENS Paris - PSL University, 3.University of Tokyo, 4.ISTEP Sorbonne University, 5.Freie Universitat Berlin, 6.Utrecht University)

The source mechanics of tectonic tremors, low amplitude-long duration seismic signals, either invokes the migration of fluids or the frictional breakdown of small ‘seismogenic’ asperities. Here, mantle rock powders containing up to 15 vol.% hydrous phyllosilicates, thought as analogues for dry and water-rich subducting lithologies, were compressed hydrostatically along a P-T path typical of hot subduction zones. Both in dry and wet lithologies, tremor-like acoustic emission (AE) signals were recorded at the same P-T conditions where natural tremors occur. Like the natural ones, experimental tremors followed a linear scaling between moment release and duration. Our experiments demonstrate that tremor signals originate from ductile or viscous deformation rather than from fluid circulations, but yet may be triggered by stress transfer at the onset of mineral dehydration.