Issues

A common problem in seismology can be illustrated by a simple analogy: Given the higher number of fatalities in this century due to grizzly bear attacks in Montana relative to New York, what can be said about the future hazard? Is New York a “bear gap,” where attacks are overdue and hence likely, or is the hazard intrinsically less? Given no information beyond the short record, either assumption is tenable because of the ambiguity involved in reasoning from the nonoccurrence of an event. To resolve the issue, we need an independent method of looking for bears.

Using the earthquake record to estimate the recurrence and hazard of future large earthquakes raises a similar problem. The historical record is short by geological standards, and the instrumental record is even shorter. Hence a standard way to obtain additional insight is to assume that earthquake occurrence is grossly linked to plate motions or intraplate deformation such that strain which accumulates on long time scales is released seismically. Although it is unclear how this process...

INTRODUCTION

In September 1996 the United Nations voted to adopt a Comprehensive Test Ban Treaty (CTBT), which prohibits any nuclear explosions, whether for weapons or peaceful purposes. The outlawing of nuclear weapons tests significantly limits a country's ability to develop or improve a nuclear weapon, so a CTBT is considered the keystone to stopping nuclear proliferation. The concept of a CTBT started with the Eisenhower administration, so the 1996 vote was truly historic. However, the UN vote to adopt the CTBT was not unanimous: 158 countries voted in favor and 3 (India, Bhutan, and Libya) opposed it, with 5 abstentions. On May 11, 1998, the one declared nuclear state which was opposed to the CTBT shocked the world by conducting a nudear test in the Rajasthan desert in northwestern India. Two days later India announced that it had conducted two further tests, and government spokesmen claimed that India needs nuclear weapons to prevent “military adventurism” by neighboring Pakistan.

On May 28, Pakistan's Prime Minister, Nawaz Sharif, announced...

INTRODUCTION

On May 1, 1998 the Central American Seismic Center (CASC) was opened in Costa Rica. The center has the purpose of permanently storing the most important data from seismic stations in Central America, as well as collecting data from Central American stations in semirealtime in order to issue daily bulletins. All data in the database will be available for access through the Internet.

BACKGROUND

In 1988 a cooperative project in disaster prevention between all Central American countries was started and organized through CEPREDENAC (Centro de Prevención de Desastres Naturales en América Central). One of the most important components in the program was seismology, and for all six countries reinstallation and/or improvement of existing analog field stations and central recording equipment was initiated. Data acquisition systems were installed in all the Central American country networks, and by the end of 1992 95 digital stations were in operation. Today the number is 138. At the same time a joint Central American effort was made to...

I've had the privilege of serving as Chief Scientist for U.S. Geological Surveys (USGS) monitoring effort in Long Valley caldera since December 1982. To some, sixteen plus years may seem like a long time to focus on a single area. I can assure you, however, that the experience has seldom provided a dull moment. Indeed, the position involves a fascinating relation between (1) scientific studies of active tectonic and magmatic processes, (2) the implications of these processes for geologic hazards, and (3) the challenges in communicating the significance of the hazards to the public and civil authorities in the area. In many ways, attempting to understand the ongoing unrest in Long Valley caldera and communicate its significance to the public represents a microcosm of the challenges that much of science faces today as we grapple with the societal relevance of our work.

SCIENCE AND HAZARDS

Long Valley caldera is a 15 km by 30 km oval-shaped topographic depression located midway between Mono Lake and...

Recently the Electronic Seismologist (ES) has been wasting his time glancing through a variety of computer trade rags and has noticed a plethora of articles with strange titles bearing little apparent relevance to the usual standard geeky bits and bytes. Being easily attracted by seemingly irrelevant titles, he became hooked on these articles comparing software development strategies with two medieval institutions. Both cathedrals and bazaars provided major focal points for the daily lives of the peasants, masters, and maybe even the seismologists of 1,000 years ago in central Europe. Both were places for obtaining nourishment (for the belly or soul), news, and information, and were centers for social interaction. Even for those who did not pray in the cathedrals or shop in the bazaars, both institutions affected their daily lives in profound ways, just as today those who don't use computer software are nevertheless affected strongly by its use around them.

Of course, the construction of a cathedral was totally different from that of a bazaar. The cathedral was carefully planned, designed...

This report includes hypocenters for seismic events that occurred in November and December 1996 as published in the Preliminary Determination of Epicenters (PDE) Monthly Listing, U.S. Geological Survey, National Earthquake Information Center. It is limited to three types of events: (1) earthquakes with a magnitude of 6.0 or greater, (2) earthquakes causing substantial damage, and (3) events of special interest.

Time is given in Coordinated Universal Time (UTC), unless otherwise specified. Latitude and longitude are given to hundredths of a degree for all locations except for events at the Nevada Test Site, which are given to hundredths of a second of arc. Depths constrained to “normal” (33 km) or other assigned depths are indicated by “constrained.” Depths determined from depth phases are marked “depth phases.” Reports followed by (GS) are taken from the PDE Monthly Listing. All reported intensities correspond to the Modified Mercalli Intensity Scale or other closely related 12-point intensity scales, unless they are designated as RF (Rossi-Forel) or JMA (japan Meteorological Agency). Sources of the magnitudes...

LLOYD CLUFF RECEIVES 1998 ALQUIST MEDAL

The California Earthquake Safety Foundation recently awarded the Alfred E. Alquist Medal to SSA member Lloyd Cluff, manager of the Geosciences Department for Pacific Gas and Electric. The award recognizes outstanding achievements in basic and applied research, public policy advancement, education, volunteer service, and program management in earthquake safety in California.

In the written citation accompanying the award, Cluff is identified as the “midwife” of the newly established Pacific Earthquake Engineering Research Center (PEER) at UC Berkeley. PEER is funded by the National Science Foundation, the State of California, and private partnerships.

AGU ANNOUNCES 1998 AGU FELLOWS

Three SSA members were chosen to be 1998 AGU Fellows. The selections are based on the individuals' attainment of acknowledged eminence in a branch of geophysics. Paul M. Davis of UCLA was cited for fundamental discoveries of the structure and stress in the Earth's crust and mantle. Brian J. Mitchell, St. Louis University, was cited for contributions that have enhanced understanding of...

Due to a printer's error, the graphics for Figures 9a and 9b, on page 246 of Haikin, Kushnir, and Dainty (1998), were reversed. The correct Figure 9a and 9b are shown below. Figure 9c of the original publication is correct.

The velocity profiles shown for sites USC03 and WOC in Figure 5, on page 227 of Boore and Brown (1998), were mistakenly a repeat of those for sites USC10 and SOW in the same figure. The correct Figure 5 is shown here. None of the other results in the paper are affected by this error.

Exotic sources of seismic waves provide interesting educational opportunities. Most seismologists are concerned with earthquakes or controlled artificial sources of waves, thus our exposure to exotic sources depends on questions from others. Such a question usually begins as, “I'm sure that this is a silly question, but did your seismograph record the —,” where “—” is some rather exotic source. Once people learn that any disturbance of the earth sends out waves and that our seismographs can record minuscule ground motions, their imagination generates seismograms that our sparse distribution of seismographs cannot record. Some examples of exotic sources are crashes of various types, sonic booms, industrial accidents, jackhammers, marching bands, various kinds of explosions, collapses of structures and natural features, thunder and other atmospheric phenomena, whales and other oceanic phenomena, etc. The recent underground nuclear tests by India and Pakistan have prompted many questions for seismologists. This interest reminds us that seismologists are obliged to be knowledgeable about exotic sources. In addition, any time that people come to us with questions, we have a...

Introducing ViSeis, a High Resolution 24/16 Bit GPS Synchronized Data Acquisition System for Seismic Applications

Palo Alto, CA—Today's seismic network operators need low-cost, user-friendly, open and extensible recording systems to handle their changing requirements. ViSeis accomplishes these goals with a design based on National Instrument's LabView, the most popular software for data acquisition.

ViSeis can be configured as an 8-channel, 24-bit system or as a 64-channel, 16-bit system. The ViSeis analog-digital conversion hardware is supplied by Symmetric Research, Las Vegas, NV, and the time base can optionally be synchronized to the PCS-GPS, a low-cost GPS module guaranteeing 5-millisecond accuracy. The ViSeis Data Source supplies data to either an STA/LTA or amplitude-trigger algorithm for automatic event recording. ViSeis is Win95/NT-based and all user interaction is handled using a mouse. There is no cryptic control file syntax to learn! All data are recorded in a standard binary format and conversion utilities are...

New Video Highlights Geoscience Careers

Careen for Geoscientists is a video created by the American Geological Institute to inspire college and high school students to pursue careers in the earth sciences. The 40-minute video introduces the wide scope of careers in the geosciences. It was created for college freshmen/sophomores and for high school juniors/seniors.

The video's theme is geoscientists' focus on exploration, discovery, and stewardship of the Earth. Interviews with eleven geoscientists reveal information about the variety of careers in the geosciences. The geoscientists profiled in the video discuss opportunities for travel, use of technology, and the chance to work outdoors—facets of the geosciences that appeal to students.

The video's release coincides with preparations for the first annual Earth Science Week, October 11–17, 1998. Information about Earth Science Week is available at http://www.earthsciweek.org.

The regular price for the video is $14.95; the AGI member society price is $12.75. Both prices include shipping...

Norman A. Abrahamson

Pacific Gas and Electric Company, San Francisco, California

Principal fields: Engineering seismology; strong ground motion; seismic hazards

Most of my thirteen years' experience as a seismologist has been in the earthquake engineering industry developing and applying methods and models for defining seismic design criteria. In addition to conducting applied research and being a user of research results, I also have experience from the funding side through a user-driven earthquake research program which is part of a public private partnership funded by PG&E. I currently serve on the board of directors of EERI.

While there are important operational issues facing the SSA (e.g., use of electronic publications, ways to increase membership, timing of annual meetings), I think that currently the main objective of the SSA should be to promote increased funding of research in seismology. I believe that the key to significant increases in funding of seismic research is to bring in private sector funding through public-private partnerships. The infusion...

At a meeting on July 10, 1998 the SSA Board of Directors approved new Bylaws to propose to the membership. Members will be asked to vote on the new Bylaws in the next annual election.

Discussion of a major revision to the old Constitution and Bylaws began in 1996 on the advice of the Society's attorney, who urged a major overhaul and modernization. SSA Secretary Joe Litehiser agreed to chair a Bylaws Committee, which reviewed SSA history, legal advice, and information on other association practices. Other members of the Bylaws Committee were Kevin Coppersmith, Walt Arabasz, and Paul Spudich.

The Board discussed and refined the proposed Bylaws at its meeting in Boulder in March 1998 and again at a special meeting in July.

These Bylaws and a more detailed explanation are posted on the SSA web site (www.seismosoc.org), along with the old Constitution and Bylaws which they would replace. The ballot on the new Bylaws will be printed on the back of the ballot for election of Directors,...

SEISMOLOGICAL SOCIETY OF AMERICA 94th ANNUAL MEETING

May 3–5, 1998 (Monday–Wednesday) Northwest Rooms, Seattle Center Seattle, Washington, USA

For Current Information: Via WWW: http://www.geophys.washington.edu/SEIS/SSA99/ Email: [email protected]

70th ANNUAL MEETING OF THE EASTERN SECTION OF THE SEISMOLOGICAL SOCIETY OF AMERICA

Site: Bolger Conference Center, Millersville University Millersville, Lancaster County, Pennsylvania

Dates: Field trip and icebreaker: October 18, 1998 Technical sessions: October 19 and 20

Co-conveners: Charles K. Scharnberger Dept. of Earth Sciences Millersviile University

Anne S. Meltzer Dept. of Earth and Environmental Sciences Lehigh University

Papers dealing with all aspects of seismology, seismicity, historical earthquakes, tectonics, seismic hazards, instrumentation, earthquake source studies, induced earthquakes, wave propagation, earth models, earth structure, earthquake engineering, sociological aspects of earthquakes, emergency management, public information and education about earthquakes are cordially invited, especially those with applications to eastern North America.

Tentative Theme Sessions

Seismicity Associated with Continental Rifts

Current Status of Networks

Induced Seismicity

Crustal Structure and Tectonics

Building Codes, Earthquake Engineering, and Insurance

Earthquake Hazard and Emergency Management

Field Trip, Sunday, Oct. 18: A Geologic...

1998

September 21–23. 20th Annual Seismic Research Symposium on Monitoring a Comprehensive Nuclear Test Ban Treaty, Santa Fe, New Mexico, USA.

The meeting is intended for al1 interested researchers on the technologies for nuclear monitoring, with particular emphasis on the fields of seismology, hydroacoustics, infrasound, and radionuclide monitoring. Charles Meade, NTPO/DoD; telephone (703) 469-1330; e-mail [email protected]. Leslie Casey, DOE; telephone (202) 586-2151; e-mail [email protected].

September 21–25. Eighth Congress of the International Association of Engineering Geology and the Environment, Vancouver, British Columbia, Canada.

Sponsored by the International Association of Engineering Geology and the Environment (IAEG) and the Canadian Geotechnical Society. The theme: “A Global View from the Pacific Rim.” 8th Congress IAEG, c/o Venue West Conference Services, Ltd., #645 - 375 Water Street, Vancouver, BC, Canada V6B 5C6; telephone (604) 681-5226; fax (604) 681-2503; e-mail [email protected]; URL http://www.bchydro.bc.ca/bchydro/iaeg.

September 21–25....