Induced earthquakes currently pose a significant hazard in the central United States, but there is considerable uncertainty about the severity of their ground motions. We measure stress drops of 39 moderate-magnitude induced and tectonic earthquakes in the central United States and eastern North America. Induced earthquakes, more than half of which are shallower than 5 km, show a comparable med...

[1] A simple dynamic model based on boundary layer theory shows that dynamic topography is unlikely to vary significantly in response to short term ( 20 Myr) variations in the mean tectonic velocity. Tectonic velocities essentially mirror variations in mantle viscosity, but are not indicative of substantial modification of dynamic topography, which primarily reflects mass anomalies in the mantl...

In two earlier papers (Wallace et al., 1983, 1985), we discussed the evidence for tectonic release from underground nuclear explosions on Pahute Mesa at the Nevada Test Site (NTS) as observed in long-period body waves. It has been shown for some time that the nonisotropic component of the surface waves from most of these events could be explained by an equivalent double-couple source; namely st...

Introduction: Dione (1124 km in diameter) is a mid-sized icy moon of Saturn which shows a wide range in tectonic features across its surface revealing an intense geologic history. With the two highly evolved satellites Enceladus und Titan, Dione forms a set of three satellites whose surfaces have been shaped by tectonic activity on a global, not only on regional scale. Tectonic forms on Dione w...

Introduction: Planar deformation features (PDFs) in quartz are diagnostic impact evidence. Using light microscopy, it is often impossible to distinguish between PDFs and tectonic deformation lamellae. [1] showed that PDFs can be imaged using a cathodoluminescence (CL) detector in a scanning electron microscope (SEM) and that in SEM-CL images PDFs can be distinguished from tectonic microfracture...

The surface of Venus displays several tectonized terrains in which the morphologic characteristics of the original materials are almost completely erased by superposed tectonic structures whose large dimensions (»100 km) suggest formation related to mantle convection. The characteristics of these tectonized terrains are in contrast to volcanic units in which tectonic structures are less signifi...

The Davisian model elucidates landscape development through an orogeny by denudation processes, postulating prolonged still-stand of a landmass following rapid tectonic uplift, ultimately resulting in a peneplain. The Penckian model emphasizes that landscape is shaped by concurrent tectonics and denudation, and includes the primary peneplain as an antithesis against the Davisian end-peneplain b...

The SH waves from 21 underground nuclear explosions at Pahute Mesa (NTS) were used to investigate tectonic release. The equivalent double-couple representation of the tectonic release, which was constrained by waveform modeling and the polarity of sP, is very similar for all the explosions. The average orientation is a right-lateral, strike-slip fault trending N15°W. Seismic moments were determ...

Completion of a global geological map of Venus has provided documentation of the relative age relationships, spatial distribution, and topographic configuration of the major geologic units and permitted us to address several important problems concerning the volcanic history of Venus. We use these data to: 1) assess the stratigraphic position of volcanic units and landforms, 2) determine their ...

Linear systems analysis is used to investigate the response of a surface processes model (SPM) to tectonic forcing. The SPM calculates subcontinemal scale denudational landscape evolution on geological timescales (1 to hundreds of million years) as the result of simultaneous hillslope transport, modeled by diffusion, and fluvial transport, modeled by advection and reaction. The tectonically for...