{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"af433915f918bfc1f4867d91b4add2447604efeea9c5fcd8b4d715e8b8290f27","created":"2026-10-03T07:18:02Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"1a0904ccd88d25e8a5dec96bae83ccfbd9a20cd9809f9ccee19791698c551d95","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":"1","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 $1e2\\,\\mathrm{cm}/\\mathrm{s}$, 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":null,"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":"1dbf2e518640764e9008c15991558e9c0810fdb6b00292d36b150438ae8a1784"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"0bc0bdd1d0504f0cfe32c90508acbfbfe3dd252413580494142e2705fb262ac3","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"12a4838c9a9399fa0a7aa5143887bd1fc918f7b43377c4d202c22b855f03ef96","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"L6kjdW0MkKoCu3qq-ooopioNg8awqfE2oY3T_HCY845sKDUzMwEs7zRCNYUba8-VBxzpyEo97g1O0NiXOgVfAg"},"schema":"pubphys.envelope/1"},"record_hash":"0bc0bdd1d0504f0cfe32c90508acbfbfe3dd252413580494142e2705fb262ac3","leaf_index":1309}