{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"96dd16604d0f9aa1da08c505dc667488b64934a60f92e77a865dab00090a33da","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["0bc0bdd1d0504f0cfe32c90508acbfbfe3dd252413580494142e2705fb262ac3","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"65ab0500433b5235773eb6cc1eefbffff124e4665d5a644830d09f27e85da5d9","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"earth.earthquake-physics.dynamic-weakening","kind":"well-posed","literature_status":"partially-resolved","n":"2","parents":[],"plain":"When fault walls slide at about a meter per second, friction drops sharply. Several processes could cause this and it is unknown which one dominates deep in real faults.","posed_since":"","precise":"At slip rates near $10^{2}\\,\\mathrm{cm}/\\mathrm{s}$, laboratory friction falls to coefficients of about 0.1 to 0.3. Identify which mechanism (flash heating at asperity contacts, thermal pressurization of pore fluid, melt lubrication, nanopowder or silica-gel lubrication) controls coseismic shear stress at seismogenic depths on natural faults, and its dependence on slip and slip rate. An answer is a constitutive law validated against natural fault-zone observations.","problem_ref":"0bc0bdd1d0504f0cfe32c90508acbfbfe3dd252413580494142e2705fb262ac3","references":"","settled_by":"Post-earthquake fault drilling with temperature measurement plus high-velocity friction experiments under in situ pressure and fluid conditions.","status_note":"Rapid-response drilling after the 2011 Tohoku earthquake measured a very low coseismic friction coefficient, but the controlling mechanism is still debated.","title":"Which dynamic weakening mechanism controls friction during earthquake slip?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"fc1b28c5e94515532d3654801a7271f48bbc3a432ad8be1f86e32db2df9e56bd","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"a61d1bd354936aab4553e332a01d7c68ea000ff63c6c0ae7726a02a3ec6a062d","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"JDp7kvDJbag6Ny2mbsYNJdwxFf0_XiUEp-Co0NfCldRYT-Dilokn8aftqrhUbOV2BokmlsEG7PI0rg7SagKxDw"},"schema":"pubphys.envelope/1"},"record_hash":"fc1b28c5e94515532d3654801a7271f48bbc3a432ad8be1f86e32db2df9e56bd","leaf_index":3188}