In JoVE (1)
Other Publications (1)
Articles by Alexandre Schubnel in JoVE
High-pressure, High-temperature Deformation Experiment Using the New Generation Griggs-type Apparatus Jacques Précigout1, Holger Stünitz1,2, Yves Pinquier3, Rémi Champallier1, Alexandre Schubnel3 1Institut des Sciences de la Terre d’Orléans (ISTO), UMR 7327, CNRS-BRGM, Université d’Orléans, 2Department of Geology, University of Tromsø, 3Laboratoire de Géologie, UMR 8538, CNRS, Ecole Normale Supérieure (ENS Paris) Rock deformation needs to be quantified at high pressure. A description of the procedure to perform deformation experiments in a newly designed solid-medium Griggs-type apparatus is here given. This provides technological basis for future rheological studies at pressures up to 5 GPa.
Other articles by Alexandre Schubnel on PubMed
Deep-focus Earthquake Analogs Recorded at High Pressure and Temperature in the Laboratory Science (New York, N.Y.). | Pubmed ID: 24052305 Phase transformations of metastable olivine might trigger deep-focus earthquakes (400 to 700 kilometers) in cold subducting lithosphere. To explore the feasibility of this mechanism, we performed laboratory deformation experiments on germanium olivine (Mg2GeO4) under differential stress at high pressure (P = 2 to 5 gigapascals) and within a narrow temperature range (T = 1000 to 1250 kelvin). We found that fractures nucleate at the onset of the olivine-to-spinel transition. These fractures propagate dynamically (at a nonnegligible fraction of the shear wave velocity) so that intense acoustic emissions are generated. Similar to deep-focus earthquakes, these acoustic emissions arise from pure shear sources and obey the Gutenberg-Richter law without following Omori's law. Microstructural observations prove that dynamic weakening likely involves superplasticity of the nanocrystalline spinel reaction product at seismic strain rates.