Alan K Yong

Updated Compilation of VS30 Data for the United States

VS30, the time-averaged shear-wave velocity (VS) to a depth of 30 meters, is a key index adopted by the earthquake engineering community to account for seismic site conditions. VS30 is typically based on geophysical measurements of VS derived from invasive and noninvasive techniques at sites of interest. Owing to cost considerations, as well as logistical and environmental concerns, VS30 data are sparse or not readily available for most areas. Where data are available, VS30 values are often assembled in assorted formats that are accessible from disparate and (or) impermanent Websites. To help remedy this situation, we compiled VS30 measurements obtained by studies funded by the U.S. Geological Survey (USGS) and...

Categories: Data; Tags: Geophysics, Seismology, USGS Science Data Catalog (SDC), United States, earthquake seismology, All tags... seismic hazard maps, seismic monitoring stations, seismic profiles, Fewer tags

High-resolution seismic data acquired at six Southern California Seismic Network (SCSN) recording stations in 2017

In August 2017, the U.S. Geological Survey acquired high-resolution P- and S-wave seismic data near six Southern California Seismic Network (SCSN) recording stations in southern California: CI.OLI Olinda; CI.SRN Serrano; CI.MUR Murrieta; CI.LCG La Cienega; CI.RUS Rush; and CI.STC Santa Clara (Figure 1). These strong-motion recording stations are located inside Southern California Edison electrical substations, critical infrastructures that provide essential services to millions of customers. The primary goals of the seismic survey were to understand the potential for amplified ground shaking and to evaluate lateral variability in shear-wave velocity at these sites. We deployed up to 88 geophones at 2-m or 4-m...

Categories: Data; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: Geophysics, Seismology, Shear-wave velocity, Southern California, USGS Science Data Catalog (SDC), All tags... earthquake hazards, ground motion, seismic refraction methods, seismology, shaking, site characterization, surface wave method, Fewer tags

Data release for: An assessment of uncertainties attributed by analysts, array types and processing algorithms for microtremor observations, using the phased 2018 COSMOS Blind Trials

The Consortium of Organizations for Strong Motion Observation Systems (COSMOS) supported blind trials using passive microtremor array data for shear-wave velocity site characterization. The trials included data from four sites in order to consider limitations imposed by differing geologies, differing sparse array geometries, and differing interpretation methodologies. The trials used a four-phase approach in order to evaluate changes in blind interpretation as each phase introduced additional array data. The microtremor array data were incrementally released to approximately a dozen analysts in four phases: (1) 2-station linear arrays; (2) sparse triangular arrays; (3) complex nested triangular or circular arrays;...

Tags: Dolphin Park, Carson, California, Geophysics, Guadalupe, San Jose, California, La Salle, Italy, Microtremor, All tags... Seismology, Trois Rivieres, Quebec, USGS Science Data Catalog (SDC), Fewer tags

Array-based Surface-wave Active- or Passive-source Recordings at 10 Seismic Station Sites in California

The dataset is consisted of travel-time records (SWM_DATA.zip) in SEG2 format recorded using multi-station MASW and AM arrays near 10 seismographic stations located in California. A table in the spreadsheet (SWM_deployment_record.xlsx) summarizes the data collection, with multiple sheets providing further details about array configurations at each station. Stations included in the dataset are CE.25091, CE.25392, CI.MAG, CI.NEE2, CI.SNR, GF.99, NC.JECB, NC.JPSB, NP.1797, and JP.1865.

Categories: Data; Tags: California, Geophysics, Seismology, USGS Science Data Catalog (SDC), seismic methods

Application of Simplified Site Characterization Method (SSCM) active- and passive-source surveys at 39 sites across California

The Simplified Site Characterization Method (SSCM) was employed to obtain VS30 data at 39 sites across California. These geophysical surveys utilized both active- and passive-source methods wherever site conditions allowed. Primary focus was on characterization of seismic stations. Major regions surveyed include the San Francisco Bay Area, Anza Valley, Imperial Valley, Los Angeles, and Santa Barbara. Also characterized were 4 PG&E dams. Active-source methods were designed for Rayleigh-wave MASW analysis, while passive-source methods were designed for use with ESAC analysis approach. Also included in this data release are data sets for geophysical surveys of five seismic stations done by standard approach surface-wave...

Categories: Data; Tags: Anza Valley, California, Geophysics, Geophysics, Imperial Valley, All tags... Los Angeles, San Francisco Bay Area, Santa Barbara, Seismology, Seismology, Site characterization, USGS Science Data Catalog (SDC), biota, Fewer tags