Archive | May 2012

Mackay awards for three NBMG employees

Congratulations to the following NBMG faculty and staff members who received the “Distinguished Service to Mackay Award” at the John W. Mackay Banquet on May 4, 2012 at the University of Nevada:

Mario Desilets
Chemist and Quality Assurance Officer
http://www.nbmg.unr.edu/Staff/Desilets.html

Terri Garside
Executive Assistant
http://www.nbmg.unr.edu/Staff/GarsideT.html

Jonathan Price
Director/State Geologist
http://www.nbmg.unr.edu/Staff/Price.html

 

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KRXI Fox 11 News Video: GPS earthquake monitoring — Geoff Blewitt interview

Geoffrey Blewitt discusses the use of GPS for monitoring tectonic activity and the possibility of a tsunami in Lake Tahoe due to a large earthquake (and what to do about it). 14 May 2012. Fox 11 News, KRXI.

Video News Clip (from UNAVCO website):  http://s3.amazonaws.com/TVEyesMediaCenter/UserContent/57211/1021706.1660/KRXI_05-15-2012_23.02.26.mp4 (Note: opens a new browser window and closes previous browser window) 

Geoff Blewitt:
http://www.nbmg.unr.edu/Staff/Blewitt.html
http://geodesy.unr.edu/

USGS News Release — LiDAR Technology Reveals Faults Near Lake Tahoe

CARNELIAN BAY, Calif. — Results of a new U.S. Geological Survey study conclude that faults west of Lake Tahoe, Calif., referred to as the Tahoe-Sierra frontal fault zone, pose a substantial increase in the seismic hazard assessment for the Lake Tahoe region of California and Nevada, and could potentially generate earthquakes with magnitudes ranging from 6.3 to 6.9. A close association of landslide deposits and active faults also suggests that there is an earthquake-induced landslide hazard along the steep fault-formed range front west of Lake Tahoe. Read full article: http://www.usgs.gov/newsroom/article.asp?ID=3218

New geologic map–San Emidio geothermal area

Open-File Report 11-11
Preliminary Geologic Map of the Northern Lake Range, San Emidio Geothermal Area, Washoe County, Nevada
by Gregory T. Rhodes, James E. Faulds, and Alan R. Ramelli
2011

Image001

This detailed geologic map (1:24,000) covers more than 50 square miles of the northern Lake Range and San Emidio Desert. It includes both the San Emidio geothermal field and Wind Mountain epithermal mineral deposit and open-pit mine. Well locations and gravity contours are shown on the map. The map also includes two detailed cross sections.

Available free on the Web:
http://www.nbmg.unr.edu/dox/of1111.pdf  (plate)
http://www.nbmg.unr.edu/dox/of1111_text.pdf  (text)

OF11-11, 1:24,000-scale color plate, 36 x 38 inches; 5-page text, b/w, $18.00
http://www.nbmg.unr.edu/sales/pbsdtls.php?sku=OF11-11

 

AEG meeting–Thursday May 17, 2012–RSVP by 5:00 PM today (Tuesday)

Craig dePolo to lead discussion on earthquake hazards

MEETING ANNOUNCEMENT
Thursday, May 17th, 2012
SPEAKER:  Craig dePolo, PhD, Nevada Bureau of Mines and Geology

LOCATION:
Reno Ramada – Skyline Room
1000 E. Sixth Street, Reno, Nevada
Link to Map

SOCIAL HOUR: 5:30 PM
DINNER: 6:00PM
PRESENTATION: 6:30PM

RSVP BY TUESDAY MAY 15 (5:00 PM) TO JESSE RUZICKA, 775-331-2375 OR JESSE.RUZICKA@AMEC.COM 

Cost:  Members: $25.00; non-members: $29.00; Students: $15.00 
(Note that the first 3 students that RSVP will receive a free dinner!)
www.aegweb.org 

“Fault Setbacks as Mitigation for Rupture Hazard in Nevada”

ABSTRACT
Craig dePolo would like to engage in a discussion of fault set-backs as a mitigation strategy for surface faulting hazard.  The Nevada Earthquake Safety Council is currently reviewing the recommended set-back strategies for surface rupture hazard from faults in Nevada.  After a presentation on the current ideas in play, we’ll collectively talk about what approaches make the most sense for Nevada and why.  As a society, we need to reduce the losses from earthquake events because it can be exceedingly difficult and take a long time to recover from an event.  But societal solutions commonly conflict with individual liberties and desires.  So what should we do, what can we do?  Can we build close to a fault with proper exploration techniques?  If so, what are those techniques and how effectively can they be implemented?  Can a geologist call the displacement on a fault during the next earthquake with confidence so buildings can be constructed across faults safely?  There are advocates of this.  What is the liability for geologists if they underestimate displacement?  Can an uncertainty statement handle this? Please bring your observations and suggestions.

BIOGRAPHY
Craig dePolo is a research geologist with the Nevada Bureau of Mines and Geology.  He is a masters and PhD graduate of the Mackay School of Mines.  He focuses on earthquake hazards, Quaternary faults, and historical earthquakes in Nevada.  He is the Northern Nevada Geoscience Representative to the Nevada Earthquake Safety Council.

UNR Seismo Lab Seminar – Monday, May 21, 2012 1:30 PM in LME 322D

Microearthquakes Associated With Long Period, Long Duration Seismic Events During Stimulation of a Shale Gas Reservoir

presented by Indrajit Das (from Zoback’s Stress and Geomechanics Group at Stanford)

ABSTRACT
Long period, long duration (LPLD) seismic events are relatively low amplitude signals that appear to be generated by slowly slipping faults during hydraulic stimulation of a gas shale reservoir. They are remarkably similar in appearance to tectonic tremor sequences observed in subduction zones and transform fault boundaries. In most cases, micro-earthquakes occur during the LPLD events, most likely generated on small fault segments associated with the slowly slipping faults responsible for the LPLD events. Interestingly, the hydraulic fracturing stages associated with the most LPLD events in the data set investigated lie exactly where there is a significant low amplitude anomaly in the 3D seismic data which we believe is due to a large density of pre-existing fractures and faults in this part of the reservoir. This region also shows the highest perturbation in pore pressure during hydraulic fracturing. From the spectrum of LPLD events we estimate that the moment carried by the larger LPLD events is ~10-20 times that of a Mw ~ -1 microearthquake. The relatively large size of these LPLD events suggests that slow slip on faults is an important process affecting the stimulation. Stimulating slip on these preexisting faults in response to elevated fluid pressures can help optimize field operations and improve recovery for shale gas reservoirs.

UNR campus map:
http://www.unr.edu/around-campus

Seismo Lab:
http://www.seismo.unr.edu/

Articles highlight research by Bill Hammond and colleagues at Nevada Geodetic Laboratory

Nevada Today (May 3, 2012):

Rapid Sierra Nevada uplift tracked by scientists at the University of Nevada, Reno—by Mike Wolterbeek

http://www.unr.edu/nevada-today/news/2012/sierra-nevada-uplift

Reno Gazette-Journal (May 5, 2012):

Mountains getting taller, stressing faults

http://www.rgj.com/apps/pbcs.dll/article?AID=/201205060600/NEWS/305060069

Geology (published online April 27, 2012; to be published in July 2012 issue):

Contemporary uplift of the Sierra Nevada, western United States, from GPS and InSAR measurements—by William C. Hammond, Geoffrey Blewitt, Zhenhong Li, Hans-Peter Plag, and Corné Kreemer

http://geology.gsapubs.org/content/early/2012/04/27/G32968.1.abstract

More about Bill Hammond’s research:

http://www.nbmg.unr.edu/Staff/Hammond.html

Nevada Geodetic Laboratory:

http://geodesy.unr.edu/