Issues

With this issue the SSA embarks venture—a journal devoted to news, opinions, and genral information about seismology and issues related to seismology. This new publication is intended to fill the gap that exists between the formal research results published in BSSA and the scribbled notes, stacks of handouts, and memories of conversations which so many of us accumulate as we pursue our work in seismology. As the editor of the New SRL, I intend to make the contents as informative, of wide interest, and as current as possible. In particular, I want to ensure that the material published in the New SRL appeals to non-specialists in seismology as well as to the active researcher.

I feel very strongly that there is a need for such an informational journal, and I know that many others agree with me. When the Eastern Section of the SSA polled its membership on this issue,...

Living in California means living with earthquakes. During the last decade alone we have experienced several damaging earthquakes, some of which have come as big surprises. We were surprised by earthquakes without surface break, surface break without much seismic radiation, and a south-dipping fault in an area of primarily north-dipping structures. Why were we taken by surprise? We were surprised primarily because the duration of our data base is so short compared with the time scale of earthquake recurrence that our knowledge is very limited.

Since the time is very limited today, let me focus our attention on Los Angeles.

Thanks to the recent advances in geophysics, geology and seismology, we now have a much better understanding of the tectonic framework of California than decades ago. As we heard in this morning's presentations, it is fair to say that the existence of the tectonic structure characterized by by the Transverse...

INTRODUCTION

The Southern California Network Bulletin began publication semi-annually as a U.S. Geological Survey Open-File Report in 1985. In 1988 it became an annual publication. The Network Bulletin is completed at the beginning of each year and contains information about Southern California Seismic Network (SCSN) activities during the previous year. Information in each bulletin includes: new stations, discontinued stations, status of earthquake data processing, CUSP (California-USGS Seismic Processing) activities, a summary of seismicity, short research articles about recent significant earthquakes in southern California or other topics related to the SCSN, and information about accessing and using the SCSN and TERRAscope data. TERRAscope is the network of high dynamic range, broadband instruments in southern California. This article contains selected parts from the Network Bulletins from 1990-1993 (Wald et al., 1991; Wald et al., 1992; Wald et al., 1993; Wald et al., 1994).

The Pasadena Office of the U.S. Geological Survey together...

INTRODUCTION

On a request from the Commonwealth Science Council, London, a mission was undertaken to investigate the earthquakes that rocked Malawi on March 9 and 10, 1989. Although it was initially proposed to carry out this mission in May 1989, due to procedural delays and other commitments, the mission could be undertaken only in October 1989. A technical report of this mission has been brought out by Commonwealth Science Council (Gupta and Malomo, 1993). In this paper we present some salient features of the field investigations of the earthquake affected area in Malawi.

TECTONICS AND SEISMICITY OF MALAWI

Malawi rift dominates the tectonics of Malawi. It is the southern portion of the western branch of the East-African rift system extending 40–90 km in width and 800 km in length. A detailed description of tectonics and seismicity associated with Malawi rift can be found in the national atlas of Malawi (Department...

SEISMOLOGY AND THE INFORMATION SUPER-HIGHWAY

Seismology has become so computationally intensive that it is a rare piece of research that is done without some part of it depending on computers. Whether it is for mathematical computations, data collection or access, text processing or figure generation, a computer is involved somewhere. Almost as rare as a seismologist without computer access is the computer without access to other computers; in other words, the network is the computer. Computer network technology is changing rapidly. Today almost all research institutions are interconnected by the Internet; tomorrow this network or its descendents will provide the same or better interconnections to all business, schools, and even private homes. Because of our longstanding intense use of computers, seismologists are and will be in the forefront of using the Intemet and will provide data and information over the network to many others including other earth scientists, engineers, government...

The 90th Annual Meeting of the Seismological Society America will be held Wednesday, Thursday and Friday, March 22, 23 and 24, 1995 in El Paso, Texas. The meeting will be held at the Student Union on the University of Texas at Paso campus. The chairperson of the meeting is Diane Doser, Department of Geological Sciences, University Texas at El Paso, E1 Paso, TX 79968 (915-747-5501).

E1 Paso is a thriving border city where American Southwest and Mexican cultures meet in the mountainous Chihuahua desert. Juarez, Mexico, a short walk across the international bridge from downtown hotels, offers colorful indoor and outdoor markets, and a variety of restaurants and nightclubs. March weather is pleasant, with daytime highs in the mid-70's. Most major airlines serve E1 Paso, and airline service links Juarez to other parts of Mexico and Latin America.

SPECIAL SESSIONS

(Conveners in parentheses.)

Microearthquake Behavior in Incipient Rupture Zones (Rick...

INTRODUCTION

There are currently several magnitude scales that are used to describe the size of earthquakes in eastern North America (ENA). These include M (moment magnitude; Hanks and Kanamori, 1979), m_N (Nutdi or Lg magnitude, often denoted m_Lg or m_bLg; Nuttli, 1973) and, most recently, m (Atkinson and Hanks, 1995). Each of these scales is based on ground motion amplitude in a different frequency band: M is a low-frequency measure, m_N is usually based on amplitudes in the 1 to 2 Hz frequency band (although this depends on the instrumentation), and m is based on high-frequency (5 to 10 Hz) ground motions.

The choice of magnitude scale is an important issue for seismic hazard analysis. It is the physical underpinning of the most fundamental building block of any seismic hazard analysis: the earthquake catalogue. In a typical probabilistic hazard analysis (e.g. Cornell, 1968; McGuire, 1977), the choice of magnitude scales...

This report includes hypocenters for seismic events that occurred in March and April 1994 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 or more, (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.” Those made to agree with 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...

HOUSE PASSES EARTHQUAKE HAZARDS REDUCTION ACT

On October 4, 1994, the House of Representatives passed the Senate Amendment in the nature of a substitute to H.R. 3485, The Earthquake Hazards Reduction Act Authorization, clearing the bill for President Clinton's signature. The bill authorizes spending in fiscal year 1995 and 1996 for the National Earthquake Hazards Reduction Program (NEHRP) and directs the President to assess U.S. capabilities in earthquake engineering research and testing.

The Federal Emergency Management Agency (FEMA), National Institute of Standards and Technology, and U.S. Geological Survey participate in NEHRP, with FEMA designated the lead agency. The Earthquake Hazards Reduction Act of 1977 created NEHRP, which supports research, applications, and emergency management to improve public safety during earthquakes. The October 4 action authorizes $103.2 million for FY 1995 and $106.3 million for FY 1996.

“For more than 15 years, this program has helped to improve performance of structure and...

I was recently asked to speak about my research in an interdisciplinary faculty seminar at Boston College. I was surprised to discover that much of what I think of as common knowledge about seismology was “news” to my audience of highly-educated faculty from across the campus. Doesn't everybody know that it is through the analysis of seismograms that we have obtained most of our knowledge about the Earth's interior? Doesn't everybody in the Boston area know that earthquakes do occur in New England, and that the reason why it is so difficult to understand their offgins is because this area is far from any plate boundaries? Doesn't everybody know that seismology is a fascinating, scientifically sophisticated, modern and multi-disciplinary science?

Brace Bolt should be commended for providing us with a valuable resource for “getting the word out” about seismology: Earthquakes and Geological Discovery is an enjoyable book that gives a...

New Releases from Earthquake Engineering Research Institute (EERI):

Northridge Earthquake. Slides: A comprehensive overview slide set, taken by the EERI reconnaissance team members and others involved in post-earthquake investigations. Covers such topics as seismology and geoscience, structural and nonstructural damage, lifeline systems, roads and bridges, and industrial facilities. The set has been created by John Hall of California Institute of Technology, and includes 70 slides with 10 pages of text. It is priced at $90 for EERI members and $105 for nonmembers.

Northridge Earthquake. Videotape. A month after the earthquake, EERI organized several technical briefings around the country based on field investigations and observations of the team. A 55-minute video, taped at one such briefing, is now available for $40 to EERI members and $45 to nonmembers. It includes presentations by the reconnaissance team members, original slides and live footage; it covers such topics as seismology and geology, strong ground...

The 1993-94 Board of Directors of the Seismological Society of America met in the Trustees' Board Room on the California Institute of Technology campus on April 4, 1994. The meeting was called to order at 10:10 AM by President Thomas H. Heaton. Present at roll call were Directors Archuleta, Heaton, Johnston, Jones, McGuire, Romanowicz, Wallace and Wesnousky. Also present: Secretary Litehiser, Treasurer Followill, BSSA Editor Langston, Directors-Elect Arabasz, Cormier and Suarez, guest, Patricia Cooper, Univ of Hawaii, Executive Director Newman and Assistant Director, Rowe. The Secretary declared that a quorum of the Board was present. Joining the meeting in progress were John Ebel, chair of the Eastern Section and Randy Keller representing the organizing committee for the 1995 Annual Meeting. The Minutes of the Board of Directors meeting of April 13, 1993, were approved as printed in the December 1993 Bulletin of the Seismological Society of America. In his report...

A message from the Editor of the Eastern Section—SSA Pages:

The new Seismological Research Letters (SRL) is here and with it the new publication forum for the Eastern Section of the SSA. The parent society has the task of publishing SRL but the ES-SSA will have pages in each issue devoted to its own specific interests. News and articles pertaining to the seismicity of the intraplate portion of North America are welcome in the ES-SSA pages. Submitted articles of current research results will be peer reviewed as before. Student contributions are welcomed. Articles pertaining to intraplate seismicity in regions outside of North America and articles determined to be inappropriate for the Eastern Section pages may be referred to BSSA for consideration. The ES-SSA pages can be used as a forum for discussion of interesting earthquakes, network operation, new maps and circulars from state and federal surveys, new equipment, software, etc....

JANUARY, 1995

January 17–20 US-Japan Workshop

EERI Committee on Urban Earthquake Hazard Reduction and Japan Institute of Social Safety Science, Osaka, Japan. (EERI, 499 14th St., Suite 320, Oakland, CA USA 94612-1902. Phone 510-451-0905. Fax 510-451-5411.)

January 23–Feb. 2 NATO Advanced Study Institute (ASI)

Monitoring a Comprehensive Test Ban Treaty, Alvor, Algarve, Portugal. Sponsored by NATO Scientific Affairs Division. (A.M. Dainty, Phillips Lab/GPE (USAF). Fax 617-377-2707. E-mail [email protected].)

FEBRUARY, 1995

February 9–11 Earthquake Engineering Research Institute

(EERI) 1995 Annual Meeting, San Francisco, CA. (EERI, 499 14th St., Suite 320, Oakland, CA USA 94612-1902. Phone 510451-0905. Fax 510451-5411.)

APRIL, 1995

April 2–7 Third International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

St. Louis, MO. (Shamsher Prakash, University of Missouri—Rolla. Phone 314-341-4489. Fax 314-341-4729/4992. E-mail [email protected].)

April 3–7 European Geophysical Society XX General Assembly

Hamburg, Germany, (EGS Office, Postfach 49, Max-Palnck-Str. 1, 37189 Katlenburg-Lindau, Germany. Phone 49-5556-1440. Fax...