Understanding the location and nature of Quaternary active crustal faults is critical to reduction both fault rupture strong ground motions hazards in built environments. Recent work along San Ramón Fault (SRF) demonstrates that seismic sources are important within Santiago Metropolitan region Chile. In this paper, we present evidence a second likely (the El Arrayán Fault, EAF) runs through nor...

The June 15, 1896 Sanriku earthquake generated devastating tsunamis with the maximum run-up of 25 m and caused the worst tsunami disaster in the history of Japan, despite its moderate surface wave magnitude (Ms=7.2) and weak seismic intensity. This is a typical tsunami earthquake, which generates anomalously larger tsunamis than expected from its seismic waves. Previously proposed mechanisms of...

Most of our understanding of earthquake rupture comes from interpretation of strongground-motion seismograms; however, near-rupture-tip fields of stress and particle motions are difficult to resolve. In particular, the decay of frictional resistance from a peak value at the leading tip of the rupture to a residual kinetic value and subsequent healing characterizes the earthquake process, yet th...

Large earthquakes are thought to release strain on previously locked faults. However, the details of how earthquakes are initiated, grow and terminate in relation to pre-seismically locked and creeping patches is unclear1–4. The 2015 Mw 7.8 Gorkha, Nepal earthquake occurred close to Kathmandu in a region where the prior pattern of fault locking is well documented5. Here we analyse this event us...

[1] We have applied a waveform cross correlation technique to study the similarity and the repeatability of more than 21,000 microearthquakes (0 <M < 4.5) in the aftershock zone of the 1984 western Nagano earthquake in central Japan. We find that the seismicity in this particular intraplate fault essentially consists of no repeating earthquakes that occurred on the same patch of the fault in a ...

Great earthquakes rarely occur within active accretionary prisms, despite the intense long-term deformation associated with the formation of these geologic structures. This paucity of earthquakes is often attributed to partitioning of deformation across multiple structures as well as aseismic deformation within and at the base of the prism (Davis et al., 1983). We use teleseismic data and satel...

This study investigates near-field ground motion variability due to dynamic rupture models with heterogeneity in the initial shear stress. Ground velocity seismograms are synthesized by convolving the time histories of slip velocity obtained from spontaneous dynamic rupture models with Green’s functions of the medium calculated with a discrete wavenumber / finite element method. Peak ground vel...

We investigate whether a shallow-dipping thrust fault is prone to waveslip interactions via surface-reflected waves affecting the dynamic slip. If so, can these interactions create faults that are opaque to radiated energy? Furthermore, in this case of a shallow-dipping thrust fault, can incorrectly assuming a transparent fault while using dislocation theory lead to underestimates of seismic mo...

Numerical models of earthquake rupture are used to investigate characteristic length scales and size distributions of repeated earthquakes on vertical, planar fault segments. The models are based on exact solutions of static three-dimensional (3-D) elasticity. Dynamical rupture is approximated by allowing the static stress field to expand from slip motions at a single velocity. To show how the ...

We study the ground motion simulations based on three finite-source models for the 2007 Mw6.6 Niigata Chuetsu-oki, Japan, earthquake in order to discuss the performance of the input ground motion estimations for the near-field seismic hazard analysis. The three models include a kinematic source inverted from the regional accelerations, a dynamic source on a planar fault with three asperities in...