Archive of shear-wave velocity versus depth profiles for hundreds of sites in Nevada, California, and New Zealand
9/6/22- For a limited time, anyone can access the full text of Louie's IMAGE'22 papers: "Detailed geophysical measurement of Vs30 for municipal building-code enforcement throughout Las Vegas Valley, Nevada, USA" and "Multidisciplinary site investigations using refraction microtremor surveys." Also get Louie's poster and talk slides.
8/26/22- Browse the COSMOS International Guidelines for Applying Noninvasive Geophysical Techniques to Characterize Seismic Site Conditions, all open-access.
The time-averaged seismic shear-wave velocity from the surface to 30 m (100 ft) depth, defined in the Building Code as Vs30, is in the United States one of the principal determinants of earthquake site-hazard classification. Over the past 20 years the Nevada Seismological Lab and the Applied Geophysics class at the University of Nevada, Reno; and Optim Earth have made shallow (<1 km deep) shear-wave velocity measurements at hundreds of sites in Nevada, California, and New Zealand using refraction microtremor (ReMi®) technology (Louie et al., 2021). Many of these measurements were made at stations in regional earthquake-monitoring networks, and sponsored by the US Geological Survey. The Google Drive link leads to a directory structure grouping the measurements by region, and the files are often named with the monitoring network station name. Each file is a self-explanatory, plain-text list of the data and results from the measurement. Where multiple files are given for a particular site, measurements were made at slightly different ReMi array locations, at different times, and by different interpreters; thus expressing both the aleatory variation of velocity in the ground and the epistemic variability of the measurement technique (+/- 15% according to Louie, 2001). Each measurement file includes ReMi array location data, a summary Vs30 value, and a modeled shear-wave-velocity-versus-depth profile. Efforts are underway to add the picked ReMi p-f image and the picked fundamental-mode Rayleigh-wave dispersion-curve data to each file. Many of these measurements have been published in peer-reviewed journal papers and project reports (available in the Preprint Archive from Louie.pub). As well, these archives give additional details on ReMi measurements found in the US Geological Survey's Vs30 archive at https://earthquake.usgs.gov/data/vs30/us/ . All data in this archive are in the public domain, distributed under a Creative Commons CC BY license.
An additional 10,722 Vs30 measurements in Las Vegas and Clark County, Nevada are available from the Clark County GIS system at http://gisgate.co.clark.nv.us/ow/ (under the "hamburger" options menu select the "Seismic" map type). A Pancha et al. (2017) paper describes these measurements.
To apply refraction microtremor technology to your engineering project, contact Terēan® at Terean.com about VsSurf ReMi® software.
Within each of the geographic/project groupings below, you link into a Google Drive folder.
Each refraction microtremor analysis result appears as a separate text file in your web browser, within the Google Drive interface.
Earthquake-monitoring site characterizations include the station code in the name of the file, so if you are looking for one of those it should be easy to find. Transect characterizations will have a site number.
Double-click on a file name within a folder to view or download the text file.
The lat/long locations of each measurement are within the text files, often along with additional location information. We are developing maps and lists to help you find sites.
All characterization text files have a shear-wave velocity versus depth, or Vs(z) profile. Depths and velocities are always metric, in meters and meters per second.
Most files give a Vs30 value; some also give Z1.0 and Z2.5 values. Some include references to the picked p-f image, and list the dispersion picks. We are in the process of populating the whole archive with those data- so let us know which sites you want us to update sooner.
You can determine the Vs30, and minimum possible Z1.0 and Z2.5 values from the Vs(z) profile, if the values are not given.
Please contact johnnlouie@gmail.com with your requests and questions.
Louie, John N. (2020). Refraction Microtremor Vs(z) Profile Archive (Version 2.0.0) [Data set]. Zenodo. http://doi.org/10.5281/zenodo.3951865
Cites all versions: DOI 10.5281/zenodo.3951864
Characterization of 11 seismic monitoring sites in Las Vegas prior to the Clark County Earthquake Parcel Map.
Forty-nine site characterizations in a transect following the Las Vegas Strip (published).
The Clark County GIS (select "Seismic" map type) archives 10,722 Vs30 results. Final project reports to Clark Co. and Henderson. A Pancha et al. (2017) paper describes these measurements, which are not in this archive.
Measurements at earthquake monitoring stations in New Zealand, most in the Wellington region. A GNS Science report describes 18 additional arrays, all within the 0.7 sq.-km Parkway neighborhood of Lower Hutt City.
Sites of precariously balanced rocks, identified between the San Jacinto and Elsinore faults by Prof. James Brune.
Fifty-four site characterizations in a transect following the Truckee River (published).
2017 presentation on basin effects on earthquake shaking with Steve Dickenson to Great Basin AEG
108 shear-velocity profiles into basement at >1 km depth in Reno and Sparks by Optim Earth. Raw model files without explanation. More to come. (Publication on 2012 results; reports to the USGS on 2014 and 2015 results).
VsSurf ReMi® software is proprietary and owned by Terēan®. John Louie is an owner of Terēan.
Research, fieldwork, and data access were supported by:
Terēan®, Bill Honjas, Dusty Barnes, and Alison Starr.
The Nevada Applied Research Initiative at UNR, Dick Bjur.
The Nevada Seismological Laboratory, especially James N. Brune, Glenn Biasi, John G. Anderson, and Graham Kent.
The CEMAT Project and the John Louie Research Fund of the UNR Foundation.
Optim Earth, Inc.
The U.S. Department of Energy under instruments numbered DE-FG07-02ID14311 and DE-FG36-02ID14311, managed through the DOE Golden Field Office, and Lisa Shevenell and Mark Coolbaugh of the Great Basin Center for Geothermal Energy at UNR.
The U.S. Geological Survey (USGS), Department of the Interior, under USGS award numbers 03HQGR0068, 05HQGR0078, 07HQGR0029, 08HQGR0015, 08HQGR0046, G09AP00050, G09AP00051, G10AP00002, G16AP00109, and G19AP00082 to Louie; and G11AP20022, G12AP20026, G14AP00020, and G15AP00055 to Optim (links to project reports, or papers); and many thanks also to Bill Stephenson.
The University of California Lawrence Livermore National Laboratory under the auspices of the U.S. Dept. of Energy under Contract No. W-7405-Eng-48. We are particularly indebted to Jane Long, Shawn Larsen, Dave McCallen, Arthur Rodgers, Jeff Wagoner, and Hrvoje Tkalcic for their very effective collaboration.
The Seismic Monitoring task of the Yucca Mountain Project, Harry Reid Center at UNLV, under the auspices of the U.S. Dept. of Energy.
The instruments used in parts of the field program were provided by the PASSCAL facility of the Incorporated Research Institutions for Seismology (IRIS) through the PASSCAL Instrument Center at New Mexico Tech. Data collected during those experiments will be available through the IRIS Data Management Center. The facilities of the IRIS Consortium are supported by the National Science Foundation under Cooperative Agreement EAR-0004370 and by the Department of Energy National Nuclear Security Administration. We wish to thank Willie Zamora, Steve Azevedo, and Marcos Alvarez for all their help over the years.
GNS Science, Lower Hutt, New Zealand, especially Stuart Henrys, Vaughn Stagpoole, Bill Stephenson, Jian Zhang, Peter Barker, and Graeme McVerry. GIS databases kindly provided by David Heron and Rafael Benites of GNS Science.
Victoria University of Wellington, New Zealand, especially John Taber, Euan Smith, Martha Savage, Tim Stern, and John Townend.
The U.S. Department of State and Fulbright New Zealand, Mele Wendt and Peggy Tramposch.
University of Texas El Paso, Texan Instrument Center, Steve Harder, Randy Keller, and Galen Kaip.
The Engineering Geophysical Lab at UNLV, especially Jim O'Donnell, and Barbara Luke, who maintained a geotechnical database for Las Vegas.
The Geosciences Dept. at UNLV, Cathy Snelson and Wanda Taylor.
Black Eagle Consulting, Inc., Reno, NV, Larry Johnson and Ted Beeston.
UNAVCO, Inc., and the National Science Foundation, Michael Hasting.
This report and the materials linked here were prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions or authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
Any measurements and observations made within approximately 50 km of Yucca Mountain, Nevada, and specifically any locations or magnitudes of seismic events, are preliminary information only. Please contact the archive of the Yucca Mountain Project Technical Library to obtain quality-assured technical data relating to seismic activity, ground conditions, or other natural phenomena near Yucca Mountain.
The information included in these documents is intended to improve earthquake preparedness; however, it does not guarantee the safety of an individual structure or facility. The State of Nevada does not assume liability for any injury, death, or property damage that occurs in connection with an earthquake.