We compare traditional methods of seismic event location, based on phase pick data and analysis of events one-at-a-time, with a modern method based on cross-correlation measurements and joint analysis of numerous events. In application to four different regions representing different types of seismicity and monitored with networks of different station density, we present preliminary results ind...

First arrivals of seismic waves were recorded along the Kamchatka arc using broadband seismic stations deployed for one year in 1998–1999. Cross correlation methods were used from a high resolution data set for tomographic inversion of body waves. The P-wave teleseismic tomography shows evidence of slab shoaling along the northern terminus of the Kamchatka subduction zone. Tomographic anomalies...

Seismic reflection and refraction images illuminate the San Andreas Fault to a depth of 1 kilometer. The prestack depth-migrated reflection image contains near-vertical reflections aligned with the active fault trace. The fault is vertical in the upper 0.5 kilometer, then dips about 70 degrees to the southwest to at least 1 kilometer subsurface. This dip reconciles the difference between the co...

Two-dimensional and three-dimensional seismic surveys were conducted across the Oquirrh fault, Utah with the purpose of imaging the fault structure to a depth of about 15 m. Results show that the 3-D tomogram clearly delineates the fault zone and a colluvial wedge, both of which correlate extremely well with the geologic cross-section interpreted from an adjacent trench. The thickness of the co...

This paper reports the findings of research examining the blast resistance of bridge piers that are designed in accordance with current knowledge and specifications to ensure ductile seismic performance. Blast testing was conducted on 1/4 scale ductile RC columns, and nonductile RC columns retrofitted with steel jacketing. The seismically designed RC and steel jacketed RC columns did not exhibi...

S U M M A R Y Theoretical studies on ambient seismic noise (ASN) predict that complete Green’s function between seismic stations can be retrieved from cross correlation. However, only fundamental mode surface waves emerge in most studies involving real data. Here we show that Mohoreflected body wave (SmS) and its multiples can be identified with ASN for station pairs near their critical distanc...

The late seismic coda may contain coherent information about the elastic response of Earth. We computed the correlations of the seismic codas of 101 distant earthquakes recorded at stations that were tens of kilometers apart. By stacking cross-correlation functions of codas, we found a low-frequency coherent part in the diffuse field. The extracted pulses have the polarization characteristics a...

Fluid circulation at fractured basement/cover unconformity is of first importance for geothermal energy exploitation especially in continental rifting as the Upper Rhine Graben. This unconformity presents lot of natural fractures which constitute a large permeable fracture network driving brine movement. That constitutes a reservoir of hot water, which is exploited by several geothermal power p...

elastic energy of seismic wave is lost through propagation into the earth. various factors affect seismic energy. some of them are frequency independent and recovered in processing steps. but other factors such as intrinsic absorption of medium are frequency dependent and cannot be recovered by processing methods. lost energy caused by these factors is called attenuation. there are various meth...