Plate tectonics is expressed most simply in oceanic plates where a thermal boundary layer or blithosphereQ forms and thickens as the plate cools during its journey away from mid-ocean ridges. Numerous studies based dominantly on surface observables have established that the oceanic lithosphere, particularly across the Pacific, does not cool continuously as it ages. Based on a seismic model of t...

Interim Reports on work of the International Institute for Applied Systems Analysis receive only limited review. Views or opinions expressed herein do not necessarily represent those of the Institute, its National Member Organizations, or other organizations supporting the work. Abstract Modeling earthquakes plays an important role in investigation of different aspects of seismic risk. The pape...

Long records of teleseismic observations accumulated at permanent seismic stations Harvard, MA; Palisades, NY; and Standing Stone, PA, in eastern North America are inverted for vertical distribution of anisotropic parameters. High-resolution anisotropy-aware P wave receiver function analysis and multiple-layer core-refracted SKS waveform modeling favor more than one layer of anisotropy beneath ...

Until the acquisition of in-situ measurements, the study of the present-day heat flow of Mars must rely on indirect methods, mainly based on the relation between the thermal state of the lithosphere and its mechanical strength, or on theoretical models of internal evolution. Here, we present a first-order global model for the present-day surface heat flow for Mars, based on the radiogenic heat ...

Direct observation and extensive sampling in ancient margins exposed in the Alps, combined with drillhole and geophysical data from the present-day Iberia margin, result in new concepts for the strain evolution and near-surface response to lithospheric rupturing at magmapoor rifted margins. This paper reviews data and tectonic concepts derived from these two margins and proposes that extension,...

We utilize earthquake recordings at two broadband seismographs located on the coast of the Gulf of Mexico to estimate Q of the mantle wedge. From the data at a station situated in the Laguna Verde nuclear power plant (LVIG), about 100 km northwest of Veracruz, and at the eastern edge of the Mexican Volcanic Belt, we estimate an upper bound of shear-wave Q of the mantle wedge, Q( f ) 120f 0.75 (...