[1] Comparison of an electrical resistivity section derived from magnetotelluric (MT) data to a geologic section extending eastward from the Sierra Nevada near latitude 36 200N shows that the crust is dominated by steeply dipping conductive features that correlate with active strike-slip faults. While there is a subhorizontal conductor at a depth 20 km beneath some of the profile, it is broken ...

[1] We derive a finite slip model for the 2013Mw 8.3 Sea of Okhotsk Earthquake (Z= 610 km) by inverting calibrated teleseismic P waveforms. The inversion shows that the earthquake ruptured on a 10° dipping rectangular fault zone (140 km× 50 km) and evolved into a sequence of four large sub-events (E1–E4) with an average rupture speed of 4.0 km/s. The rupture process can be divided into two main...

Tectonic motion across the Los Angeles region is distributed across an intricate network of strike-slip and thrust faults that will be released in destructive earthquakes similar to or larger than the 1933 M6.4 Long Beach and 1994 M6.7 Northridge events. Here we show that Los Angeles regional thrust, strike-slip, and oblique faults are connected and move concurrently with measurable surface def...

[1] We have used magnetotelluric data imaging to determine the resistivity structure across southern Kenya and our results suggest the presence of a buckled blocky or segmented lithosphere across the region. Prominent steep conductive zones at the Oloololo (OLO) escarpment and eastern rift margin allow us to subdivide the region into three crustal domains. West of OLO, a bow-shaped conductor un...

The December 26, 2004 Sumatra–Andaman Island earthquake, which ruptured the Sunda Trench subduction zone, is one of the three largest earthquakes to occur since global monitoring began in the 1890s. Its seismic moment was M0 = 1.00 · 10–1.15 · 10 Nm, corresponding to a moment-magnitude of Mw = 9.3. The rupture propagated from south to north, with the southerly part of fault rupturing at a speed...

Fault geometry, depth, and slip distribution of the Sanriku-oki earthquake of December 28, 1994 (Ms 7.5) are estimated from seismic waveforms, geodetic measurements, and tsunami waveforms, and compared with those of the 1968 Tokachi-oki earthquake (Mw 8.2), the most recent large earthquake in the epicentral region. Seismic wave inversions indicate a shallowly dipping thrust type mechanism and t...

In this study, we analyze the fault and fracture network of Middle Triassic carbonate platform Lastoni di Formin (Italian Dolomites, Italy). The reconstruction deformation history is primary importance for a full comprehension present structural setting platform. huge dimensions body superb exposure its vertical cliffs gently dipping top plateau make an ideal outcrop to integrate traditional fi...

Seismic reflection profiles, drill-hole data, and geologic maps delimit the form of normal faults and Tertiary sedimentary rocks in the southern half of the Cache Valley basin in northern Utah. Dips of faults and sedimentary rocks were estimated from time-migrated reflection profiles by using the stacking velocities for the data. At the southern end of the basin, the East Cache fault zone is li...

We use horizontal and vertical crustal displacements derived from GPS measurements at 26 sites in western Mexico to study the coseismic and post-seismic kinematics and dynamics of the 1995 October 9 (Mw=8.0) Colima–Jalisco earthquake along the Middle America Trench. The measurements bracket the entire landward edge of the approximately 150 km long rupture zone and span a 4 yr period for most si...

Abstract Earthquake stress drop Δ σ is related to fault slip via , where μ D and L c denote shear modulus, average slip, dimension. C controlled by the system geometry, characterizes effective stiffness of system, commonly assumed be a constant near 1. We use 3D elastostatic models systematically investigate how burial depth, dip angle, direction. find that decreases with smaller depth value fo...