More available at my PhD thesis.
Embedded Files
Deep & Intermediate-depth Earthquakes
Deep & Intermediate-depth Earthquakes
On 24 May 2013, a Mw 8.3 earthquake ruptured a 180km long fault within the subducting Pacific plate about 609 km below the Sea of Okhotsk. Global seismic P wave recordings indicate ER ~ 1.5×1017 J. Vr ~ 4.0 -4.5 km/s is determined by back-projection of short-period P waves, and the fault width is constrained to give static stress drop estimates (~12 to 15 MPa) compatible with theoretical radiation efficiency for crack models. A nearby aftershock had a stress drop ~1-2 orders of magnitude higher, indicating large stress heterogeneity in the deep slab, and plausibly within the rupture process of the great event.
Rupture process of the 23 June 2014 Mw 7.9 Rat Islands archipelago, Alaska, intermediate-depth earthquakes [Ye et al., 2014, GRL].
Sanriku-Oki Low-Seismicity Region
Sanriku-Oki Low-Seismicity Region
We studied the seismicity and deformation in the plate boundary region north of 2011 Tohoku (Mw 9.0) earthquake along the coast of Honshu, seeking to understand why that huge rupture produced very little slip in this region. We argue that a region with low “seismic” coupling with significant quasi-static deformation exists along the Sanriku region, and this low seismicity, apparently predominantly stably sliding region limited the northward down dip extent of the mainshock rupture [Ye et al., 2011].
Fault Interactions in Subduction Zones
Fault Interactions in Subduction Zones
The spatial and temporal variation of interplate megathrust events and seaward intraplate events, including shallow tensional events and deep compressional events, in subduction zones has been studied for indication of elastic interactions that may be useful for evaluating seismic coupling and earthquake hazard. We analyze an intraplate sequence in 2012 near a seismic gap along the Philippine Trench which suggests large potential for a great earthquake in this region if it is significantly seismically coupled [Ye et al., 2012, GRL]. To further explore seismic cycle stress change interactions within the intraplate environment in the outer rise and beneath the outer trench slope, we have been systematically assembling a global catalog of the near-trench intraplate events from 1976 to 2012 at depth smaller than 70 km in all major subduction zones using the CMT database,finding a substantial success in anticipating where thrusting occurred.
Strike-Slip earthquakes along Transform Plate Boundary
Strike-Slip earthquakes along Transform Plate Boundary
We quantify the rupture processes of the two largest earthquakes, 2003 Mw 7.6 and 2013 Mw 7.8, along the southern Scotia Ridge between the Scotia Sea Plate and Antarctica. There are two unusual and surprising aspects of the earthquake: the shallow dip of the strike-slip faulting suggests reactivation of a former thrust fault, and the short apparent time for re-rupture of the segment. Modeling of teleseismic waves and GPS recording at BORC suggest complementary slip distributions comprising a relatively uniform offset along the SSRT.
Ground Shaking and Seismic Source Spectra for Large Earthquakes in Subduction Zones
Ground Shaking and Seismic Source Spectra for Large Earthquakes in Subduction Zones
The variation in friction properties along the megathrust in subduction zones became of interest to me, and I contribute to a systematic examination of depth-varying seismic radiation characteristics in the vicinity of several great interplate ruptures, finding systematic increases in high-frequency radiation with increasing source depth along the megathrusts [Lay et al., 2012, JGR].
We used regional strong-motion accelerometers (K-net, and Kik-net) and high-quality borehole velocity sensors (Hi-net) in Japan to extend this investigation to large earthquake seismic radiation and ground shaking for several intraplate and interplate events near the Japan megathrust. This extended work quantifies the path attenuation and source spectral characteristics of seismic radiation with depth along the megathrust and between the megathrust and intraplate environments, and accounts for differences in ground shaking and associated hazard. We demonstrate the validity of inferences made from teleseismic P wave spectra for characterizing the source radiation differences [Ye et al., 2013, BSSA].
Google Sites
Report abuse