Belle E Philibosian

2017 seismic imaging of the West Napa Fault Zone, St. Helena, California

In April 2017, the U.S. Geological Survey acquired high resolution P- and S-wave seismic data across the suspected trace of the West Napa Fault zone in St. Helena, California. We acquired seismic reflection, refraction, and guided-wave data along a 215-m-long profile across the expected trend of the West Napa Fault zone. To acquire the reflection and refraction data, we co-located shots and geophones, spaced every 2 m along the profile. We used 109 SercelTM L40A P-wave (40-Hz vertical-component) geophones with a sensitivity of 22.34 volts/meter/second to record 108 P-wave shots, and 109 SercelTM L28-LBH S-wave (4.5-Hz horizontal-component) geophones with a sensitivity of 31.3 volts/meter/second to record 108 S-wave...

Categories: Data; Tags: Geophysics, Saint Helena, Seismology, USGS Science Data Catalog (SDC), earthquakes, All tags... faulting (geologic), hazards, seismic reflection methods, seismic refraction methods, seismology, Fewer tags

Coachella eastern trench (T2) overview photos

See parent item for full description. File names indicate the location of the section in the following form: N or S designates northwest or southeast wall and numbers following "m" are in meters (measured from the southwest end of the logged exposures). Single photomosaics of the northwest and southeast wall are also included.

Pre-existing features associated with active faulting in the vicinity of the 2019 Ridgecrest, California earthquake sequence

This dataset is composed of linear active tectonic and other relevant features (scarps, deflected drainages, and lineaments and contrasts in topography, vegetation, and ground color) mapped based on high-resolution topography, aerial/satellite imagery, and field observations. The mapping covers the area surrounding the 2019 Ridgecrest, California earthquake surface ruptures. Point locations of field observations are also included.

Tags: China Lake, Coso Basin, Geomorphology, Indian Wells Valley, Ridgecrest, All tags... Salt Wells Valley, Seismology, Spangler Hills, Teagle Wash, USGS Science Data Catalog (SDC), earthquakes, geospatial datasets, hazards, Fewer tags

Coachella central trench (T1) overview photos

See parent item for full description. File names indicate the location of the section in the following form: N or S designates northwest or southeast wall and numbers following "m" are in meters (measured from the southwest end of the logged exposures).

Coachella central trench (T1) northwest wall photomosaics

See parent item for full description. Most files are photomosaics of sections of wall. File names indicate the location of the section in the following form: N or S designates northwest or southeast wall, number following "b" gives the bench riser number (1 is at the top), and numbers following "m" are in meters (measured from the southwest end of the logged exposures). A few files are original unrectified images of 1 m x 0.5 m grid rectangles. These follow the same naming convention above, giving the meter number at the southwest side of the grid rectangle followed by a capital letter indicating the half-meter measured from the top of the trench (e.g., letter H is the 8th half-meter, meaning horizontal strings...