Subsections


Director's Report

Introduction

As in previous years, I am pleased to introduce the 2009-10 Berkeley Seismological Laboratory Annual Report. This report covers two interrelated activities at BSL: basic research and real time earthquake monitoring operations. Chapter 2 describes the research accomplishments; Chapter 3 details progress in our development of infrastructure and facilities.

The basic research spans many topics in seismology and tectonics. They range from studies of the earth's deep structure and dynamics to various aspects of earthquake physics; from microearthquakes and tremor studies to studies of earthquake mechanisms and rupture spanning different times scales; and from slow tectonic deformation to real time seismology and earthquake early warning. These are described in 25 "two-page" contributions in Chapter 2 of this report. Highlights this year include a collection of studies at different scales of the upper mantle seismic isotropic and anisotropic structure beneath North America, taking advantage of the new broadband seismic dataset provided by the USArray component of the NSF funded national Earthscope program ( Chapter 2, Research Sections 8, 9, 10, 12, and 11 ).

This year has been quite busy on the operational side of the BSL, owing to significant funding received through the USGS, in the framework of ARRA, to upgrade the recording systems at many of our broadband and borehole stations. We have already upgraded two-thirds of our broadband stations with state of the art Quanterra Q330 dataloggers, and we are starting to upgrade those at our borehole stations. These upgrades were much needed, as many of the recording systems were 15-20 years old, well beyond the expected lifetime of computer hardware. We have also received funding to upgrade receivers at our 26 BARD stations and to add GPS receivers at 7 of our existing BDSN stations. The new receivers will allow us to stream high rate (1Hz sampling) GPS data and to start implementing the use of GPS data in our real-time earthquake analysis procedures. Much effort has also gone into redesigning the data processing procedures and the web presentation for the continuous GPS data from the BARD network.

We have continued our involvement in the redesign of the STS-1 very broad band seismometer, under Metrozet's leadership, and with funding from the NSF EAR-Instruments and Facilities Program. The development phase is practically finished, and the new instruments are now being tested and fine-tuned not only at our Byerly Vault but also at Harvard (HRV) and the Albuquerque Seismological Laboratory.

The following sections give a brief historical overview of the BSL, and finally some BSL staff news.

History and Facilities

The Berkeley Seismological Laboratory (BSL), formerly the Berkeley Seismographic Stations (BSS), is the oldest Organized Research Unit (ORU) on the UC Berkeley campus. Its mission is unique in that, in addition to research and education in seismology and earthquake-related science, it is responsible for providing timely information on earthquakes (particularly those that occur in Northern and Central California) to the UC Berkeley constituency, to the general public, and to various local and state government and private organizations. The BSL is therefore both a research center and a facility/data resource, which sets it apart from most other ORUs. A major component of our activities is focused on developing and maintaining several regional observational networks, and participating, along with other agencies, in various aspects of the collection, analysis, archival, and distribution of data pertaining to earthquakes, while maintaining a vigorous research program on earthquake processes and Earth structure. In addition, the BSL staff spends considerable time on public relations activities, including tours, talks to public groups, responding to public inquiries about earthquakes, and, more recently, World-Wide-Web presence (http://seismo.berkeley.edu/). UC Berkeley installed the first seismograph in the Western Hemisphere at Mount Hamilton (MHC) in 1887. Since then, it has played a leading role in the operation of state-of-the-art seismic instruments and in the development of advanced methods for seismic data analysis and interpretation. Notably, the installation, starting in 1927, of Wood-Anderson seismographs at 4 locations in Northern California (BKS, ARC, MIN, and MHC) allowed the accurate determination of local earthquake magnitude ($M_{L}$) from which a unique historical catalog of regional earthquakes has been maintained to this day, providing crucial input to earthquake probabilities studies.

Over the years, the BSS continued to keep apace of technological improvements. The first centrally telemetered network using phone lines in an active seismic region was installed by BSS in 1960. The BSS was the first institution in California to operate a 3-component ``broadband" system (1963). It played a major role in the early characterization of earthquake sources using ``moment tensors" and source-time functions. The BSS also made important contributions to the early definitions of detection/discrimination of underground nuclear tests and, jointly with UCB Engineering, to earthquake hazards work. Starting in 1986, the BSS acquired 4 state-of-the-art broadband instruments (STS-1), while simultaneously developing PC-based digital telemetry, albeit with limited resources. As telecommunication and computer technologies made rapid progress, in parallel with broadband instrument development, paper record reading was completely abandoned in favor of largely automated analysis of digital data.

The current facilities of BSL have been built progressively over the last two decades, efforts initiated by significant ``upgrade" funding from UC Berkeley in 1991-1995. The BSL currently operates and acquires data, continuously and in real-time, from over 60 regional observatories. These house a combination of broadband and strong motion seismic instrumentation installed in vaults, borehole seismic instrumentation, the permanent GPS stations of the Bay Area Regional Deformation (BARD) network, and electromagnetic sensors. The seismic data are fed into the BSL real-time processing and analysis system. Since 1996, they are used in conjunction with data from the USGS NCSN network in the joint earthquake notification program for Northern California. This program capitalizes on the complementary capabilities of the networks operated by each institution to provide rapid and reliable information on the location, size and other relevant source parameters of regional earthquakes. In recent years, a major emphasis in BSL instrumentation has been in densifying the state-of-the-art seismic and geodetic networks. At the same time, research efforts have been directed toward the development of robust methods for quasi-real time, automatic determination of earthquake source parameters and predicted strong ground motion, using a sparse network combining broadband and strong motion seismic sensors, as well as permanent geodetic GPS receivers. Recently, research emphasis has been directed toward the development of ``earthquake early warning'' capabilities

The Berkeley Digital Seismic Network (BDSN), a regional network of 32 digital broadband and strong motion seismic stations with continuous telemetry to UC Berkeley, is the backbone of the BSL operations. This network contributes basic regional data for real-time estimation of location, size and rupture parameters for earthquakes in Central and Northern California. It is the Berkeley contribution to the California Integrated Seismic Network (CISN). In June 2009, our operational software, the Rapid Eathquake Data Integration (REDI) program, was replaced by the CISN, now AQMS, software (see Chapter 3, Operational Section 8). The data from the BDSN also provide a fundamental database for the investigation of three-dimensional crustal structure and its effects on regional seismic wave propagation. This is ultimately crucial for estimating ground shaking for future earthquakes. Most stations also record auxiliary temperature/pressure channels, valuable in particular for background noise quality control. Complementing this network is a $\sim 25$ station ``high-resolution" network of borehole seismic sensors located along the Hayward Fault (HFN) and under the Bay Area bridges, operated jointly with the USGS/Menlo Park and linked to the Bridge Safety Project of the California Department of Transportation (Caltrans). The latter has facilitated the installation of sensor packages at 15 bedrock boreholes along 5 East Bay bridges in collaboration with Lawrence Livermore National Laboratory (LLNL). A major science goal of this network is to collect high signal-to-noise data for micro-earthquakes along the Hayward Fault to gain insight into the physics that govern fault rupture and its nucleation. The BSL also operates and maintains the 13 element Parkfield borehole seismic array (HRSN). This array provides high quality data on micro-earthquakes, clusters and most recently tremors, and is an important reference for the San Andreas Fault Observatory at Depth (SAFOD). Since April 2002, the BSL collaborates with MBARI on the operation of a permanent broadband ocean bottom station, MOBB.

In addition to the seismic networks, the BSL operates, maintains and processes data from the 26 permanent geodetic stations of the BARD Network. It archives and distributes this data as well. Where possible, BARD sites are collocated with BDSN sites to minimize telemetry costs. In particular, sites are progressively being upgraded to 1 Hz sampling. This will support one focus of BSL research, the development of analysis methods which combine seismic and geodetic data to rapidly estimate source parameters of significant earthquakes.

Finally, two of the BDSN stations (PKD, SAO) also share data acquisition and telemetry with 5-component electromagnetic sensors installed with the goal of investigating the possibility of detection of tectonic signals. In 2002-2003, automated quality control software was implemented to monitor the electromagnetic data.

Archival and distribution of data from these and other regional networks is performed at the Northern California Earthquake Data Center (NCEDC), operated at the BSL in collaboration with USGS/Menlo Park. The data reside on a mass-storage device (current holdings $\sim 50$ terabytes), and are accessible ``on-line'' over the Internet (http://www.ncedc.org). Among others, data from the USGS Northern California Seismic Network (NCSN), are archived and distributed through the NCEDC. The NCEDC also maintains, archives and distributes the ANSS earthquake catalog.

Core University funding to our ORU has until now provided salary support for one staff scientist and several technical and administrative staff members, representing about 30% of the total infrastructure support. The remaining support comes from extra-mural grants and contracts, primarily from the USGS, NSF, and the State of California, through its Emergency Management Agency (CalEMA, formerly OES). We acknowledge valuable recent contributions from other sources such as Caltrans and PEER, as well as our Earthquake Research Affiliates. The effects of drastic budget cuts in FY09-10 are temporarily being offset by ARRA funding from the USGS.

BSL staff news

Changes in BSL staff in 2009-10 are as follows.

In the past year, the following graduate students associated with BSL completed their PhD's: Ved Lekic graduated in December 2009 and joined Brown University in May on an NSF post-doctoral fellowship. Trey Apel completed his doctorate in April 2010, and Gilead Wurman in May 2010. They are now working in industry at AMEC Geomatrix and Seismic Warning Systems, respectively.

There has been one new arrival: Andrea Chiang joined the BSL as a graduate student in the Fall of 2010.

BSL hosted the following visiting scientists in 09-10: Dr. Joshi Karra from the National Geophysical Research Institute, Hyderabad, India, and Yann Capdeville, from IPGP in France.

As a result of a campus-wide reorganization of the research administration of Organized Research Units, our four administrative staff were laid off, effective November 30, 2009. Tina and Yolanda were rehired at RES (Research Enterprise Services), the agency which provided business administration for BSL from December 2009 thru June 2010. After a brief sojourn at RES, Kristen Jensen, our former manager, joined EFA. They are very fortunate to have her! All three have been outstanding members of the BSL team, and we are sorry to see them go despite all our efforts. Fortunately, we were able to rehire Kate Lewis in March 2010 as Executive Assistant, to coordinate the programmatic aspects of BSL administration during the RES tenure. Kate has also played a major role in helping organize the 6 week long CIDER-2010 summer program in Santa Barbara, CA (http:/www.deep-earth.org/2010/summer10.html) and the international SEDI 2010 symposium that followed from July 18-23, 2010. Since July 2010, BSL administration has been consolidated with that of the Earth and Planetary Science department, and Kate is now in charge of the coordination of all funds and transactions related to the BSL operations, as well as handling many everyday tasks while we wait for the hire of two additional administrative staff, jointly with EPS.

Finally, Rick McKenzie retired in June 2010. We miss him!

The greater BSL family has continued to grow in the past year, with the arrival of Audrey Lewis in October 2009. She was followed by Freeman McCarty and Arieh Wurman-Fenton in November 2009, Henry Allen in April 2010, and Rebekah Zheng in June 2010.

Acknowledgements

I wish to thank our technical and administrative staff, scientists and students for their efforts throughout the year and their contributions to this Annual Report. Individual contributions to activities and report preparation are mentioned in the corresponding sections, except for the Appendix section, which was prepared by Jennifer Taggart.

I also wish to specially thank the individuals who have regularly contributed to the smooth operation of the BSL facilities: Mario Aranha, Rich Clymer, Doug Dreger, John Friday, Jarrett Gardner, Peggy Hellweg, Ingrid Johanson, Bill Karavas, Oleg Khainovski, Rick Lellinger, Pete Lombard, Rick McKenzie, Bob Nadeau, Doug Neuhauser, Charley Paffenbarger, Jennifer Taggart, Taka'aki Taira, Bob Uhrhammer, and Stephane Zuzlewski, and in the administrative office, Kristen Jensen, Kate Lewis, Tina Barber-Riggins, and Yolanda Andrade. I also wish to thank our undergraduate assistants, Chris Rawles, Danny Feucht, Josef Matlak, Eric Winchell, and Amanda Truyol, for their contributions to our research and operations activities.

I am particularly grateful to Jennifer Taggart and Peggy Hellweg for their help in putting together this Annual Report and bringing it to completion.

The Annual Report of the Berkeley Seismological Laboratory is available on the Web at http://seismo.berkeley.edu/annual_report.


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