J. Louie 12/10/2003J. Louie 12/10/2003

Using Refraction Microtremor reconnaissance: Rapid surveys take advantage of urban noise More details at www.seismo.unr.edu/hazsurv

QuickTime™ and aMotion JPEG OpenDML decompressorare needed to see this picture.

Surveying Seismic Microzonation in Surveying Seismic Microzonation in Urban AreasUrban Areas

J. Louie 12/10/2003J. Louie 12/10/2003

ReMi measures Rayleigh dispersion with linear refraction arrays (paper by Louie, April 2001 BSSA).

Refraction Microtremor for Shallow Shear VelocityRefraction Microtremor for Shallow Shear Velocity

100-m depth resolution

Initial funding from SCEC, UNR, VUW, Optim LLC

J. Louie 12/10/2003J. Louie 12/10/2003

ReMi has classified hard and soft sites around the world by measuring V30, average shear velocity to 30 m depth.

Refraction Microtremor for Shallow Shear VelocityRefraction Microtremor for Shallow Shear Velocity

J. Louie 12/10/2003J. Louie 12/10/2003

Local reconnaissance was first test.Reno TransectReno Transect

Supported by UNR and IRIS-PASSCAL

J. Louie 12/10/2003J. Louie 12/10/2003

Unexpected results: high V30 in active alluvium.Reno TransectReno Transect

West East

Ta

J. Louie 12/10/2003J. Louie 12/10/2003

Lack of V30 correlation to geologic or soil maps

Reno TransectReno Transect

Only Tertiary Andesite (Ta) shows a characteristic V30

J. Louie 12/10/2003J. Louie 12/10/2003

The First Reno Hazard MapThe First Reno Hazard Map

J. Louie 12/10/2003J. Louie 12/10/2003

July 2003 San Gabriel Valley & Los AngelesShallow Shear-Velocity TransectsShallow Shear-Velocity Transects

B

C

D

E

Transect mapped on NEHRP hazard class map by Wills, from SCEC Phase 3 Report

Supported by USGS, NEHRP ERP and IRIS-PASSCAL

J. Louie 12/10/2003J. Louie 12/10/2003

200 shallow Vs profiles from San Gabriel Riv.

Los Angeles TransectLos Angeles Transect

San Gabriel Mts.are C, not B.

Alamitos Bayis D, not E.

V30 may correlate with hydraulic gradient.

J. Louie 12/10/2003J. Louie 12/10/2003

No V30 correlation with active vs. older alluvium; R2 = 0.2!Los Angeles TransectLos Angeles Transect

J. Louie 12/10/2003J. Louie 12/10/2003

Las Vegas route from Cheyenne to Tropicana

1-km-deep basin

3-km-deep basin

Supported by DOE-LLNL and IRIS-PASSCAL

Shallow Shear-Velocity TransectsShallow Shear-Velocity Transects

J. Louie 12/10/2003J. Louie 12/10/2003

Some correlation to faulting, soil type?Las Vegas TransectLas Vegas Transect

J. Louie 12/10/2003J. Louie 12/10/2003

No correlation between V30 and geologic map.Las Vegas TransectLas Vegas Transect

J. Louie 12/10/2003J. Louie 12/10/2003

Correlation with clay soils, caliche in Las Vegas?Las Vegas TransectLas Vegas Transect

J. Louie 12/10/2003J. Louie 12/10/2003

Shallow section & V100 hint at stratigraphy, faulting?

Las Vegas TransectLas Vegas Transect

QuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.

Fault?

Caliche?

J. Louie 12/10/2003J. Louie 12/10/2003

A Preliminary A Preliminary Las Vegas Las Vegas

Hazard MapHazard Map

Transect V30 values correlated with soil-map units across 4 quadrangles in Las Vegas Valley

J. Louie 12/10/2003J. Louie 12/10/2003

Example of public outreach:Discoveries and Breakthroughs Inside Science, news shorts funded by AIP, AGU, etc.

QuickTime™ and aH.263 decompressorare needed to see this picture.

OutreachOutreach

KFSN-TV Fresno, CAKGBT-TV Harlingen, TXKJTV-TV Lubbock, TXKTRK-TV Houston, TXKNBC-TV Burbank, CAKNSD-TV San Diego, CAKQTV-TV St. Joseph, MOKNTV-TV San Francisco, CAKRQE-TV Albuquerque, NMKTSM-TV El Paso, TXKTVN-TV Reno, NVKWQC-TV Davenport, IAKXAS-TV Fort Worth, TXWAGM-TV Presque Isle, MEWTEN-TV Albany, NYWCAU-TV Philadelphia, PAWCMH-TV Columbus, OHWCYB-TV Bristol, VAWEWS-TV Cleveland, OHWFTS-TV Tampa, FLWLUK-TV Green Bay, WIWBBH-TV Fort Myers, FL

WHIO-TV Dayton, OHWIS-TV Columbia, SCWJAR-TV Cranston, RIWLBT-TV Jackson, MSWMAQ-TV Chicago,ILWNBC-TV New York, NYWNCN-TV Raleigh, NCKTSM-TV Omaha, NEWPBN-TV Traverse City, MIWSYM-TV Lansing, MIWTVJ-TV Miami, FLWVIT-TV Hartford, CTWVTM-TV Birmingham, ALWXYZ-TV Southfield, MIWJXT-TV Jacksonville, FLWTXL-TV Tallahassee, FLWIVT-TV Binghamton, NYWEVV-TV Evansville, INWCJB-TV Gainesville, FLWPXI-TV Pittsburgh, PACHAT-TV Medicine Hat, ALB K. Heineman, NewsProNet, Producers

Technology Transfer: Commercial ReMi is now in use by geotechnical consultants and agencies worldwide.