2-2-2-2-2-2-2-2-2-2-2-2-2 From: Daniel Juncu <D.Juncu@xxxxxxxxxxx> Dear Colleagues, The Centre for Observation and Modelling of Earthquakes, Volcanoes, and Tectonics (COMET) invites you to the next instalment of our webinar series, viewable from the home office. Coming up next: *Dr. Sam Wimpenny *(University of Cambridge) *Measurements of the Rheology of Active Faults.* The webinar will take place on *Thursday the 25th of June 2020 at 16:00 UK time* (GMT+1). *If you want to attend the webinar please register at https://us02web.zoom.us/webinar/register/WN_GDxQNuuCQFe21TbWuu6QiQ <https://us02web.zoom.us/webinar/register/WN_GDxQNuuCQFe21TbWuu6QiQ>* (After registering, you will receive a confirmation email containing information on how to join the webinar) *Abstract* *I will discuss new constraints on two enigmatic features of fault rheology: (1) the slip-rate dependent friction in the shallow parts of fault zones, and (2) the static frictional resistance to slip in lower-crustal fault zones. The first part of the talk will argue for a physical mechanism to reconcile observed differences in the amount of shallow post-seismic deformation following earthquakes, which is based on the relative fraction of locked to creeping areas on faults. The second part of the talk will combine observations from earthquake seismology, active tectonics, laboratory experiments and real rocks to argue that, within the foreland shields bounding large mountain belts, lower-crustal fault zones can be seismogenic and weak. Commonly-invoked hydrolytic weakening mechanisms for faults, such as phyllosilicate formation and near-lithostatic pore-fluid pressures, are unlikely to apply to the lower crust of shields, given the nominally anhydrous phase assemblages within exhumed analogue metamorphic terrains. Therefore the physical mechanism(s) causing weak, yet seismogenic, lower-crustal faults remain enigmatic. The talk will end with a shameless promotion of a new COMET data product we have recently compiled â?? the Global Waveform Catalogue (gWFM).* 2-2-2-2-2-2-2-2-2-2-2-2-2 ============================================================== Volcano Listserv is a collaborative venture among Arizona State University (ASU), Portland State University (PSU), the Global Volcanism Program (GVP) of the Smithsonian Institution's National Museum of Natural History, and the International Association for Volcanology and Chemistry of the Earth's Interior (IAVCEI). ASU - http://www.asu.edu/ PSU - http://pdx.edu/ GVP - http://www.volcano.si.edu/ IAVCEI - https://www.iavceivolcano.org/ To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxx. To contribute to the volcano list, send your message to: volcano@xxxxxxx. Please do not send attachments. ============================================================== ------------------------------ End of Volcano Digest - 10 Jun 2020 to 12 Jun 2020 (#2020-61) *************************************************************
