Skip to main content
U.S. flag

An official website of the United States government

Vs30 Models and Data Active

By Earthquake Hazards Program October 23, 2019

The following resources are available for Vs30 (the time-averaged shear-wave velocity to 30 m depth) models and data.

Global Slope-Based Vs30

Vs30 can be approximated via correlation to topographic slope. See Wald and Allen (2007) and Allen and Wald (2009) for details.

Global Vs30 Mosaic

Based on topographic slope, with custom embedded maps (Worden et al., 2015).

U.S. Vs30 Compilation

Compiled Vs30 measurements obtained by studies funded by the U.S. Geological Survey (USGS) and other governmental agencies. Thus far, there are 2,997 sites in the United States, along with metadata for each measurement from government-sponsored reports, Web sites, and scientific and engineering journals. Most of the data originated from publications directly reporting the work of field investigators. A small subset (less than 20 percent) of Vs30 values was previously compiled by the USGS and other research institutions. Whenever possible, Vs30 originating from these earlier compilations were crosschecked against published reports.

Both downhole and surface-based Vs30 estimates are represented. Most of the VS30 data are for sites in the western contiguous United States (2,141 sites), whereas 786 Vs30 values are for sites in the Central and Eastern United States; 70 values are for sites in other parts of the United States, including Alaska (15 sites), Hawaii (30 sites), and Puerto Rico (25 sites).

References

  • Worden, C. B., D. J. Wald, J. Sanborn, and E. M. Thompson, 2015, Development of an open-source hybrid global Vs30 model, Seismological Society of America Annual Meeting, 21-23 April, Pasadena,      California.

Below are publications associated with this project.

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
Authors
Alan Yong, Eric M. Thompson, David J. Wald, Keith L. Knudsen, Jack K. Odum, William J. Stephenson, Scott Haefner
By
Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

On the use of high-resolution topographic data as a proxy for seismic site conditions (VS30)

An alternative method has recently been proposed for evaluating global seismic site conditions, or the average shear velocity to 30 m depth (VS30), from the Shuttle Radar Topography Mission (SRTM) 30 arcsec digital elevation models (DEMs). The basic premise of the method is that the topographic slope can be used as a reliable proxy for VS30 in the absence of geologically and geotechnically based s
Authors
T.I. Allen, D. J. Wald

Topographic Slope as a Proxy for Seismic Site-Conditions (VS30) and Amplification Around the Globe

Executive Summary It is well-known that large global earthquakes can have a dramatic effect on local communities and the built environment. Moreover, ground motions amplified by surficial materials can exacerbate the situation, often making the difference between minor and major damage. For a real-time earthquake impact alert system, such as Prompt Assessment of Global Earthquakes for Response
Authors
Trevor I. Allen, David J. Wald
  • Overview

    The following resources are available for Vs30 (the time-averaged shear-wave velocity to 30 m depth) models and data.

    Global Slope-Based Vs30

    Vs30 can be approximated via correlation to topographic slope. See Wald and Allen (2007) and Allen and Wald (2009) for details.

    Global Vs30 Mosaic

    Based on topographic slope, with custom embedded maps (Worden et al., 2015).

    U.S. Vs30 Compilation

    Compiled Vs30 measurements obtained by studies funded by the U.S. Geological Survey (USGS) and other governmental agencies. Thus far, there are 2,997 sites in the United States, along with metadata for each measurement from government-sponsored reports, Web sites, and scientific and engineering journals. Most of the data originated from publications directly reporting the work of field investigators. A small subset (less than 20 percent) of Vs30 values was previously compiled by the USGS and other research institutions. Whenever possible, Vs30 originating from these earlier compilations were crosschecked against published reports.

    Both downhole and surface-based Vs30 estimates are represented. Most of the VS30 data are for sites in the western contiguous United States (2,141 sites), whereas 786 Vs30 values are for sites in the Central and Eastern United States; 70 values are for sites in other parts of the United States, including Alaska (15 sites), Hawaii (30 sites), and Puerto Rico (25 sites).

    References

    • Worden, C. B., D. J. Wald, J. Sanborn, and E. M. Thompson, 2015, Development of an open-source hybrid global Vs30 model, Seismological Society of America Annual Meeting, 21-23 April, Pasadena,      California.
  • Publications

    Below are publications associated with this project.

    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
    Authors
    Alan Yong, Eric M. Thompson, David J. Wald, Keith L. Knudsen, Jack K. Odum, William J. Stephenson, Scott Haefner
    By
    Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center

    On the use of high-resolution topographic data as a proxy for seismic site conditions (VS30)

    An alternative method has recently been proposed for evaluating global seismic site conditions, or the average shear velocity to 30 m depth (VS30), from the Shuttle Radar Topography Mission (SRTM) 30 arcsec digital elevation models (DEMs). The basic premise of the method is that the topographic slope can be used as a reliable proxy for VS30 in the absence of geologically and geotechnically based s
    Authors
    T.I. Allen, D. J. Wald

    Topographic Slope as a Proxy for Seismic Site-Conditions (VS30) and Amplification Around the Globe

    Executive Summary It is well-known that large global earthquakes can have a dramatic effect on local communities and the built environment. Moreover, ground motions amplified by surficial materials can exacerbate the situation, often making the difference between minor and major damage. For a real-time earthquake impact alert system, such as Prompt Assessment of Global Earthquakes for Response
    Authors
    Trevor I. Allen, David J. Wald