S U M M A R Y Pacific Ocean crust west of southwest North America was formed by Cenozoic seafloor spreading between the large Pacific Plate and smaller microplates. The eastern limit of this seafloor, the continent–ocean boundary, is the fossil trench along which the microplates subducted and were mostly destroyed in Miocene time. The Pacific–North America Plate boundary motion today is concent...

Abstract We determine high‐resolution 3‐D seismic images ( Vp , Vs and / ) of the Alaska‐Aleutian forearc region, which are used to further estimate serpentinization volume fraction subducting Pacific slab. Our results show that hydration degree lower plate is high in Shumagin Gap but relatively low Semidi Kodiak segments, roughly shows a trend eastward decrease correlated with an increase inte...

Seismic anisotropy is sensitive to the alignment of minerals, fluid-filled cracks, and fractures caused by fault deformation, thus providing a signature especially in aseismic layer. In this study, we use seismic traveltime tomography study spatial distribution azimuthal region 2013 Mw 6.6 Lushan earthquake. Our analysis reveals both stress-induced structure-controlled mechanisms. The seismicit...

Abstract Cores recovered during the International Continental Scientific Drilling Program project “Drilling into Seismogenic zones of M2.0 to M5.5 earthquakes in deep South African Gold Mines” include fault breccia from within aftershock cloud 2014 Orkney earthquake (M5.5). The and surrounding intrusive rocks, probably lamprophyres rich talc, biotite, calcite, amphibole, had high magnetic susce...

Because large earthquakes have repeatedly occurred in subduction zones, it is important to observe seismic activities on the sea floor. An ocean bottom cabled seismometers (OBCS) system is the most suitable tool for this purpose since data can be obtained in real-time. Although the existing OBCS systems are useful for the study of seismic activities, the number of stations is limited due to the...

An offshore zone of faulting approximately 10 km from the southern California coast connects the seismically active strike-slip Newport–Inglewood fault zone in the Los Angeles metropolitan region with the active Rose Canyon fault zone in the San Diego area. Relatively little seismicity has been recorded along the offshore Newport–Inglewood Rose Canyon fault zone, although it has long been suspe...

[1] We examine the frictional behavior of a range of lithified rocks used as analogs for fault rocks, cataclasites and ultracataclasites at seismogenic depths and compare them with gouge powders commonly used in experimental studies of faults. At normal stresses of ∼50 MPa, the frictional strength of lithified, isotropic hard rocks is generally higher than their powdered equivalents, whereas fo...

[1] One way to probe the rheology of the lithosphere and fault zones is to analyze the temporal evolution of deformation following a large earthquake. In such a case, the lithosphere responds to a known stress change that can be assessed from earthquake slip models constrained from seismology and geodesy. Here, we model the postseismic response of a fault zone that is assumed to obey a rate-str...