The opinions expressed in this PWSRCAC commissioned report are not necessarily those of PWSRCAC. The 1964 earthquake demonstrated that the Valdez area is subject to enormous earthquakes and coeval tsunamis. The geologic record of prehistoric earthquakes and tsunamis in the Valdez area has not previously been studied. Historic and prehistoric paleotsunami deposits were identified during this stu...

Regional ground-motion generation and propagation must be characterized to adequately assess seismic hazard. In the Cascadia region of southwestern British Columbia and northwestern Washington, the ground-motion issues are particularly complex because of the contributions to hazard from five distinct types of events, all of which behave differently in terms of their ground-motion propagation ch...

We analyze the seismic moment-frequency relation in various depth ranges and for different seismic regions, using Flinn-Engdahl’s regionalization of global seismicity. Three earthquake lists of centroid-moment tensor data have been used: the Harvard catalog, the USGS catalog, and the HUANG et al. (1997) catalog of deep earthquakes. The results confirm the universality of the b-values and the ma...

The spatial distribution of seismicity is often used as one of the indicators of zones where future large earthquakes are likely to occur. This is particularly true for intraplate regions such as the central and eastern United States, where geology is markedly enigmatic for delineating seismically active areas. Although using past seismicity for this purpose may be intuitively appealing, it is ...

We determined the energy release in earthquakes using the data obtained from TriNet in southern California. We investigated the effects of the depth, the mechanism and the propagation path by examining the results for events with different mechanisms and depths. We found that the path and site effects dominate so much that these effects are not obvious. By far the most dominant is the path-site...

[1] The Zagros mountains of southern Iran are marked by a zone of high seismicity and accommodate a significant portion of the convergence between Arabia and Eurasia. Due to the lack of dense local seismic or geodetic networks, the inferred kinematics of the collision in Iran is mainly based on catalogs of teleseismically determined earthquake locations. We surveyed all Mw > 4.5 earthquakes in ...

Rapid procedures (i.e. within 5 to 15 minutes) for earthquake and tsunami early warnings focus on earthquake location, depth, magnitude, and slowness, but initial tsunami early warnings are more often issued without knowing the mechanism of the earthquake. Kawakatsu (1998) proposed using a limited number of stations to automatically detect, locate and determine the source parameters of earthqua...

Intermediate-depth earthquakes (30-300 km) have been extensively documented within subducting oceanic slabs, but their mechanics remains enigmatic. Here we decipher the mechanism of these earthquakes by performing deformation experiments on dehydrating serpentinized peridotites (synthetic antigorite-olivine aggregates, minerals representative of subduction zones lithologies) at upper mantle con...

An increase in the number of smaller magnitude events, retrospectively named foreshocks, is often observed before large earthquakes. We show that the linear density probability of earthquakes occurring before and after small or intermediate mainshocks displays a symmetrical behavior, indicating that the size of the area fractured during the mainshock is encoded in the foreshock spatial organiza...

It is rare to find earthquakes with depths greater than 30 km in continent–continent collision zones because the mantle lithosphere is usually too hot to enable brittle failure. However, a handful of small, intermediate-depth earthquakes (30–97 km) have been recorded in the continental collision region in central South Island, New Zealand. The earthquakes are not associated with subduction but ...