As part of a series of seismic experiments designed to improve the understanding of the impact of mining blasts on verifying a Comprehensive Test Ban Treaty, a sixteen station network of three-component seismic sensors were deployed around a large cast shot in the Black Thunder Mine. The seismic stations were placed, where possible, at a range of 2.5 kilometers with a constant inter-station spa...

We have observed that Vibroseis wavelets behave very much as if they are minimum phase. This was discovered by applying minimum-phase Wiener deconvolution to the separated vibroseis VSP downgoing waves and observing that the result is effectively a band-limited spike. Motivated by this finding, we simulated a synthetic nonstationary vibroseis wavelet in a constant-Q medium by nonstationary conv...

A novel imaging process, referred to as vector image isochron (VII) migration, is specifically designed to reduce artifacts caused by arrays with limited apertures. By examining the assumptions behind generalized Radon transform (GRT) migration, a new approach is found which identifies and suppresses array artifacts, based on the array geometry and the migration earth model. The new method work...

The seismic methods are the most powerful existing technique to image the structure of the Earth’s subsurface. Depending on the system layout, the seismic methods can be divided into near-vertical reflection (NVS) techniques and wide-angle reflection/refraction (WAS) techniques. In contrast to NVS, the development of WAS preprocessing tools has deserved only minor attention to date and most exi...

Vasospasm (VSP) is one of the major causes for prolonged neurologic deficit in patients with aneurysmal subarachnoid hemorrhage. Few case series have reported about continuous local intra-arterial nimodipine administration (CLINA) in refractory VSP. We report our experience with CLINA in a patient with refractory cerebral VSP.

Site U1328 (Scientific Prospectus Site CAS-06A) is located within a seafloor cold-vent field, with dimensions 2 km by 4 km, consisting of at least four vents associated with nearsurface faults. The cold vents are characterized by near-vertical seismic blank (or wipe-out) zones that are between 80 and several 100 m wide, and show a clear E-W trend as identified from 3D seismic imaging. The most ...

Mycoplasma bovis, the most important etiological agent of bovine mycoplasmosis, undergoes extensive antigenic variation of major and highly immunogenic surface lipoprotein antigens (Vsps). A family of 13 related but divergent vsp genes, which occur as single chromosomal copies, was recently found in the chromosome of M. bovis. In the present study, the molecular mechanism mediating the high-fre...

Time migration velocity analysis can be performed by velocity continuation, an incremental process that transforms migrated seismic sections according to changes in the migration velocity. Velocity continuation enhances residual normal moveout correction by properly taking into account both vertical and lateral movements of events on seismic images. Finite-difference and spectral algorithms pro...

Time-migration velocity analysis can be performed by velocity continuation, an incremental process that transforms migrated seismic sections according to changes in the migration velocity. Velocity continuation enhances residual normal moveout correction by properly taking into account both vertical and lateral movements of events on seismic images. Finite-difference and spectral algorithms pro...

Forward modeling of reflection seismic data is a computational process through which a geologic model (units: horizontal distance, vertical depth; layer acoustic impedance) of the subsurface is transformed into a synthetic reflection seismic record (units: horizontal distance, 2-way travel time; reflection amplitude). Synthetic seismic records (synthetics) are often generated both before and af...