Shallow Seismic Wave Velocity Database for Las Vegas Basin
- readme.txt file last updated 06/12/07 by H. Murvosh, B. Luke and E. Gonzalez

This compilation is a result of the Las Vegas Seismic Response Project sponsored
by the Lawrence Livermore National Laboratory (www.llnl.gov) and the Earthquakes 
in Southern Nevada Project (http://earthquakes.unlv.edu) sponsored by the US 
Department of Energy. These shear- (Vs) and compression- (Vp) wave velocity measurements
were compiled by the Engineering Geophysics Laboratory (EGL) at the University of Nevada, 
Las Vegas (www.ce.unlv.edu/egl). The data sources include measurements made by the EGL 
and its research partners, data collected by others and given to us to post, and records
filed with the Clark County Building Department (http://www.co.clark.nv.us). 
For the velocity measurements made by others that are not otherwise publicly available, 
permission was granted for their use in research.  The EGL does not ensure the accuracy 
or quality of datasets reported by others.

Data are grouped on the website as follows: each dataset that was collected by the EGL 
or provided to us in detail has a bold header which denotes the site’s name.  Some locations
encompass many measurements, using different techniques.   Data acquired from the 
Clark County Building Department are listed together under “CC Public Records.” 

Velocity profiles from surface wave measurements (SASW, MASW, ReMi) are provided as 
step functions. Crosshole and downhole data are provided as point measurements.  For the 
Clark County data, layering was interpreted manually by EGL researchers from digitized plots 
submitted to the County with the geotechnical reports. The 30-meter, depth-averaged 
shear-wave velocity (VS30) values for these files are taken directly from the reports.  

File format:

All file names have 6 characters plus extension “.txt”: 
Characters 1-3:  Site identification, assigned by EGL
4.    Type of measurement: S - SASW; D - Downhole; C - Crosshole; R - ReMi
5.    Type of energy:  S - Shear; P - Compression 
6.    Measurement number (to distinguish multiple measurements at a site)

Each file has eleven header lines. The first line contains the full name of the site. 
The header also contains location (lat/long), cross streets, type of measurement, and 
more. If some of this information is not available for a site, the detail is left blank. 

The last header line in each file introduces the depth-versus-velocity data columns. 
The data are in tab-delimited format.  The first column is depth and the second is velocity. 
All data are presented in SI units (meters, meters per second). 

The entire, up-to-date data set can be downloaded in a zip file by clicking on “Click to 
download all Vs here.”

This database will be continuously enriched as new datasets become available. If you have
data to contribute, or if you have any comments or questions, please contact Dr. Barbara Luke 
at barbara.luke@unlv.edu or (702)895-1568.  

-----------------------
Sample:   CSNRS1.txt

Site name: Community College of Southern Nevada- Cheyenne Campus
Cross streets: 
Lat/long: 36.22/-115.11
Date: August 20, 2002
Performed by: UNR-T.Rasmussen (with J. O'Donnell)
Type of measurements: ReMi
Depth of measurements: 130.8 m
Function stepped (y or n): y 
Posted by: Ying Liu 10/3/2003
Vs30 (m/s):  
Depth (m) Vs(m/s)
0	532
14.955	532
14.955	308
30.804	308
30.804	971
130.8	971