Bob de Groot distributes press kits and friendly greetings.

Chris Wills explains a Phase III poster.

Text and photos by John Marquis

The announcement of research that located "hotspots" of ground-motion amplification in the Los Angeles area turned the Davidson Executive Conference Center at USC into a kind of "media hotspot" on Tuesday, January 16, as reporters from over 30 different news organizations converged to hear what SCEC scientists had to say. The press conference was organized by Mark Benthien (SCEC) and Bob Calverley (USC News Service) with the help of many others.

[For an overview of the Phase III report and technical resources, visit the SCEC Phase III web page.]

The press conference, which represented the official release of the results of years of research conducted by the SCEC Phase III working group, was set to begin at 10 a.m. in the conference center's Figueroa Room. As the hour approached, members of the press arrived and were welcomed by Bob de Groot (SCEC), who handed out press kits full of relevant information, including the joint USGS/SCEC fact sheet. Crews from television stations (there were 13 represented!) were also given a video tape of "B-roll footage" -- broadcast-quality versions of the images and animations used in the presentation. Those who arrived early had a chance not only to claim seats and the prime spots for their cameras, but also to conduct brief interviews with some of the scientists involved. Some were able to get first-hand explanations of background material that was central to the research announcement. By the time the conference began, representatives from a diverse cross-section of southern California's television, radio, and print media -- a total of 30 different organizations -- filled the conference room.

A phalanx of cameras spanned the width of the Figueroa Room.

Tom Henyey delivers his opening remarks at the Phase III press conference.

With a phalanx of cameras set in place across the width of the room, Dr. Tom Henyey, SCEC's Executive Director, delivered opening remarks. Explaining that SCEC is a National Science Foundation (NSF) Science and Technology Center that receives its funding from both the NSF and the U.S. Geological Survey (USGS), Henyey reviewed the Center's goals and its current status as a means of setting the background for the presentation of the Phase III results. He pointed out that SCEC, entering its eleventh -- and potentially final -- year of funding, has actively worked not only on sponsoring the research of earth scientists, but on "integrating or pulling together results from a variety of different studies of earthquakes to improve our seismic hazard models." This integration of research, Henyey said, has led to the publication of three major reports over the last ten years."

Henyey explained that "the first report investigated the implications of the 1992 Landers earthquake on the future seismicity of southern California, and in particular, its effect on the nearby San Andreas fault." (As an indication of the Center's commitment, this study was labelled the "Phase I" report.) One of the results of the second report (known as "Phase II"), "a comprehensive study of earthquake probabilities over the next 30 years for southern California," said Henyey, was "a map of southern California depicting those areas where earthquake shaking is expected to be more frequent or intense" relative to other areas. This map of seismic hazard has been distributed to the public throughout southern California as part of the booklet Putting Down Roots in Earthquake Country.

The third report ("Phase III") -- the "most ambitious, to date," according to Henyey -- was produced by SCEC in collaboration with the USGS, the California Division of Mines and Geology (CDMG), and the California Department of Transportation (Caltrans), and relied on the contributions of "more than 20 researchers." The Phase III report, Henyey said, "deals with the fundamental questions of whether site effects can be accounted for in seismic hazard analysis." Though the results presented at this press conference represent "a partial answer to these questions," Henyey cautioned, "there is still much more work to be done." And with that, he turned over the podium to Ned Field, a scientist from the Pasadena office of the USGS, and the lead author of the SCEC Phase III report.

Ned Field of the USGS summarizes the science and results of the Phase III report.

The audience follows along with Ned Field's PowerPoint™ presentation.

Upon taking the podium, Dr. Ned Field thanked everyone present for their attendance and acknowledged the contributions of the 20 other scientists in the SCEC Phase III Working Group. To understand how those scientists came to identify "hotspots" of shaking amplification in the Los Angeles region, Field said, it is important to understand the basics of seismic hazard assessment. With that, he began a PowerPoint™ presentation explaining the background and summarizing the results of the study conducted by the Phase III Working Group.

Field noted that while there are two parts to seismic hazard analysis -- earthquake forecasting and ground shaking estimation -- Phase III was concerned only with the latter. Showing two animations of the shaking from a simulated earthquake, he demonstrated how shaking can be dramatically affected by variations in the composition and structure of the rocks beneath us. This is, by no means, an entirely new idea, he said; John Milne, a pioneer in the field of seismology, had noticed 100 years ago that the shaking at two sites only 1000 feet apart could differ in intensity by a factor of 10! Far more recently, the Northridge earthquake sparked a renewed interest in this phenomenon by generating small pockets of intense shaking in unexpected areas.

Field pointed out that when discussing shaking, the emphasis is not so much on ground motion, as it is on the response of buildings to that motion. Ignoring variations in geology (as was the case in the first of the two animations he showed), Field said, there are two factors that influence the amount of shaking from an earthquake that a given location will experience: the magnitude of the earthquake and the distance from the earthquake's source. He demonstrated these with a pair of plots using data from past events in southern California. Magnitude alone can generate variations of about a factor of 10, over the range of damaging magnitudes (M 5 to M 7.5) expected in southern California. The difference in shaking between a location right above the source and one 100 kilometers away is typically about a factor of 20.

But local geology can also affect the amount of shaking at a site, Field said. Prior to the Northridge earthquake, the distinction made for changes in geology was simply "soil vs. rock," with soil expected to shake about 1.5 times more than rock. According to Field, one fundamental question the Phase III Working Group wanted to answer was, "Can we do better than rock vs. soil?" With the help of a map created by Chris Wills and others from the California Division of Mines and Geology (CDMG), the answer is yes, he said. This map shows the "softness" -- the speed of shear waves in the upper 100 feet of the Earth's crust -- of rocks all across California. From this, the working group was able to determine that the difference in shaking would be about 2.5 times more for the "softest" sites than for the "hardest."

Since the Northridge earthquake, the effect that basins can have on local shaking has also been under intense study. In particular, the depth of the sediments beneath a site can influence the amount of shaking at that site. Field showed the results of the working group's investigations into basin depth as an animated 3D map of the Los Angeles area. Comparing the effects of a basin to a bowl of gelatin, he said that this data provided a "good view of the shape of this bowl for the Los Angeles Basin," and that the difference in shaking between the edge and the center of such a basin will be about a factor of two.

Taken together, Field said, these findings constitute "a substantial improvement in our ability to predict areas where the shaking will be more than in other areas." His point was illustrated by a slide showing the new Phase III shaking amplification map next to a map that might have been prepared for similar purposes prior to the Phase III study. The difference in the figures was clear -- the old map showed only the difference between hard rock and soft soil in southern California, while the new map showed distinct "hotspots" in some of the local basins where shaking, on average, could be expected to be many times greater than in more stable areas. But the working group, he claimed, also came to another very important conclusion: "in addition to the average behavior shown in our new map, each earthquake will also have its own unique pattern of hotspots." He showed the audience maps of the resulting hotspots from four different earthquake simulations, and said that "these types of simulations constitute our only realistic hope of making more accurate shaking predictions in the future; making them reliable enough for general engineering use will require a concerted effort even larger than that reflected in the SCEC working group study we're discussing today."

To conclude, Dr. Field outlined four steps for following up on the research conducted by the SCEC Phase III Working Group. The first step is the dissemination of this research, published in the form of 14 technical papers that make up a special issue of the Bulletin of the Seismological Society of America (BSSA). Second, Field said that "earthquake engineers, insurance companies and emergency management officials will evaluate the implications of [these] findings and modify their strategies accordingly." Third, Field called on his fellow scientists to "proceed with the challenging task of devising more reliable case-by-case scenario earthquake simulations." And finally, echoing the beginning of his talk, he expressed the need to "return to the other half of seismic hazard analysis" -- the attempt to forecast where and how often large earthquakes are likely to occur in southern California.

Dr. James Whitcomb (NSF) addresses SCEC's progress as part of the STC Program.

Dr. Patrick Muffler (USGS) expresses his support for the Phase III project.

Following Ned Field was Dr. James Whitcomb, acting Deputy Division Director for the Division of Earth Sciences of the National Science Foundation (NSF). Dr. Whitcomb said he was "very pleased to be here on this occasion," and called the study "a very important milestone in the life of the Southern California Earthquake Center." SCEC was founded as part of the NSF's Science and Technology Center (STC) Program more than 10 years ago. An essential goal of the STC program, Whitcomb noted, was to create centers in such a way that each turned out to be "greater than the sum of its parts." Said Whitcomb, "this is indeed the case at the Southern California Earthquake Center, in that they have led the way in integrating several different scientific disciplines, integrating earthquake engineers, and integrating partnerships with agencies -- federal, state and local -- to address the problem of seismic hazard, [thereby] reducing the loss of property and life from earthquakes." Dr. Whitcomb closed his remarks by congratulating the center on its progress.

Tom Henyey then introduced Dr. Patrick Muffler, the western regional geologist for the USGS based in Menlo Park, California. Dr. Muffler said he was "pleased to be [there] representing Chip Groat, director of the [United States] Geological Survey in Reston, Virginia." From the USGS point of view, he said he wanted to emphasize how "scientifically fruitful" the partnership with SCEC has been, and that the USGS looks forward to more collaboration with SCEC in the future. He called the results of the Phase III report "exciting, good stuff" that should complement the Advanced National Seismic System under development by the USGS. Thanking the group for giving him the opportunity to speak at the press conference, Dr. Muffler said he anticipates seeing many more refinements to this kind of study, and in general, "more interesting [results] coming out of SCEC in the next few years."

Jim Davis (CDMG) discusses his department's involvement in the Phase III project.

Ed Bortugno (OES) speculates on the possible application of Phase III results.

The next official introduced by Tom Henyey was Dr. James Davis, the state geologist for the California Department of Conservation's Division of Mines and Geology (CDMG). On behalf of all the CDMG staff, Davis said it "has been our pleasure" to have worked with SCEC "since its inception over 10 years ago." He said he wanted to "observe the contributions that the state has made scientifically to [the Phase III] effort" and also "consider... some of the public policy applications the state is responsible for applying in its effort to protect the safety and reduce the damage its citizens are subjected to."

Speaking of the Phase III report, Davis called it "a continuum point in the development of an increasingly rigorous understanding of the earthquake shaking potential in southern California." Indicating the CDMG map of rock "softness" data, referred to by Ned Field in his presentation, Davis said the CDMG was "delighted at the application of this data in Phase III." Noting that another of the state's contributions to the study was a set of data from the strong motion instrumentation program, Davis added that "the governor's office has chosen to put" a total of $6.8 million in funding toward "a statewide seismic mointoring network,... an expansion of TriNet, in the governor's budget for the coming year." This funding, he said, "will enhance and increase the activity of monitoring earthquakes in southern California" and expand "greatly the monitoring of earthquakes in northern California," both of which "are important to estimating the loss that is to be expected from future earthquakes."

Next up at the podium was Ed Bortugno, senior geologist for the California Governor's Office of Emergency Services (OES), representing the director of the OES, Dallas Jones. He thanked SCEC, the USGS and the CDMG for inviting the OES to comment on what he called "this new important research." According to Bortugno, one of the "prime responsibilities" of the OES "is to provide good loss information" after any kind of destructive event. This information can be used to ask for federal funds if the event becomes a "presidentially declared disaster." As an example of the importance of making accurate loss estimates, he explained that, within about 24 hours after the Northridge earthquake, the computer model used then by the OES "estimated about $13 to 15 billion in damage," while the actual damage figures "are probably closer to about $40 billion." "So," Bortugno said, "information such as [the Phase III report] is going to only help us improve these estimates."

Bortugno said that "another use of loss modeling" is the "prioritization of mitigation in California." He pointed out that while we have good building codes now, we have "a large number of old buildings that were built prior to these... building codes," and so "we need to begin the process of retrofitting these structures to make them safer." Information like that in the Phase III report, Bortugno claimed, "is going to help us prioritize those areas where we need to do it first."

Ellis Stanley (City of LA) address the importance of Phase III to emergency preparedness personnel.

Lucy Jones (USGS) addresses the audience and fields questions.

The next official to speak was Ellis Stanley, general manager of the Emergency Preparedness Department for the City of Los Angeles. From his point of view, the most important thing about the announcement of the new Phase III results is likely to be their impact on the process of planning and development that goes on in the city of Los Angeles. He remarked that 25 years ago, when he started working in the field of emergency preparedness, or even "as recently as Northridge," no one had this kind of information to take before the city council and argue persuasively for the implementation of stronger safety standards or a prioritization of areas with buildings in need of seismic retrofit. Mr. Stanley also suggested that the work behind today's announcement could add realism to future emergency preparedness drills, like the "full-scale unannounced test" of response in the wake of a simulated magnitude 6.8 earthquake on the Palos Verdes fault zone to occur sometime in the near future. Finally, he added that he hoped that this report and the efforts of SCEC partnerships would better "help citizens understand their potential hazard."

Finally, Tom Henyey introduced Dr. Lucy Jones, who he called southern California's "earthquake mom" (she is locally famous for appearing with her sons on post-earthquake TV coverage) and who is now scientist-in-charge of the earthquake hazards program of southern California at the office of the USGS in Pasadena. She prefaced her remarks by stating that she was speaking that day in three different capacities: as a scientist of SCEC, as a federal official trying to reduce the earthquake hazard in southern California, and as a citizen of southern California.

Addressing the significance of the Phase III findings, Jones made reference to a common saying of hers: "Earthquakes don't kill people, buildings do." This is a clever way of saying that if we want to prevent loss of life in a future earthquake, we don't so much need a better understanding of the earthquake itself, but rather, we need a "better picture of what the earthquake will do to buildings," according to Jones. One of the primary applications of this research, she said, echoing Ed Bortugno, should be as a tool to prioritize retrofitting of older buildings. She also noted that the study's results could have the more subtle application of allowing better data interpolation between the TriNet stations used to generate ShakeMap, the graphical view of ground motion created in the wake of signficant earthquakes.

As for inappropriate uses of the Phase III findings, Jones said that this report is "not something someone will go look at to help decide where to buy a house." Saying that this should be just another tool to help average citizens manage their risk, she pointed out that if you were to move away from the shaking amplification of the basins, you would be moving "toward the brush fires." That produced a chuckle from the audience, but her point was made. She wrapped up by explaining why she sees SCEC as a valuable resource to research in southern California. She said SCEC's greatest sucesses have been the creation of a "consensus voice" among scientists from different institutions and the bringing together of the "best minds..., turning [research] into practical products."

Ned Field responds to a question asked of the panel.

The crowd listens attentively to the panel.

Ed Bortugno responds to a question from the audience at the end of the panel session.

At the end of her speech, Lucy Jones introduced the four scientists on the "panel of experts" that would respond to questions from the floor. On the panel were Ned Field of the USGS, Harold Magistrale from the University of California at San Diego, Kim Olsen from the University of California at Santa Barbara, and Chris Wills from the CDMG. The officials also remained at the front of the room, to step up to the podium and help address questions if necessary.

One of the first and most poignant questions came in response to a comment from Ned Field about each earthquake having its own unique "hotspots." If that's the case, it was asked, then what good is this study? Field countered that since it's impossible to know where the next big earthquake will be, the average behavior is more useful to know -- "we don't want to get too hung up on the details," he said.

It was brought up that the publication of the map of hotspots might cause some concern among those people who live near the center of those hotspots, such as the one near the intersection of the 105 and 710 freeways. "What do you say to those folks?" asked one reporter. To answer that, Ned Field echoed Lucy Jones' warning from earlier in the conference, saying that this study should not be considered the end-all, and that there are other things to think about when computing your risk. "I don't think... someone should consider moving on the basis of this amplification," Field added.

The recent destructive earthquake in El Salvador was brought up several times during the question-and-answer session. Responding to a question about turning this research into policy, Ellis Stanley said that "in my business, we have small windows of opportunity; I dare say that had we not had our little shake Saturday" (referring to a magnitude 4 earthquake near Sylmar) "or did not have El Salvador, half of you wouldn't be here -- maybe two-thirds of you wouldn't be here." And in another question, the panel was asked how this kind of study might help "third-world countries like El Salvador," and how such a country could "find the money to do this." Ned Field responded that while it was true that small countries might not be able to conduct such a study independently, the SCEC Phase III Working Group has already found a lot of the "pitfalls," thus "saving other countries from going through that learning process" so that they can streamline their efforts.

Harold Magistrale and Ned Field are interviewed after the conference.

Lucy Jones is interviewed by several local television stations.

Kim Olsen explains Phase III results to a reporter.

SCEC's Tom Jordan is interviewed at the end of the press conference.

Mark Benthien, Tom Jordan, and John McRaney (SCEC) talk with Peggy Brutsche (Red Cross) and Jack Popejoy (KFWB).

After the panel session was over, media representatives were given the chance to conduct individual interviews with the scientists and officials involved in the Phase III project. Some of these were quite formal, with cameras rolling, while other interviews more closely resembled private, informal conversations. Tom Henyey talked about the Center's work, Harold Magistrale discussed the subsurface geology of the Los Angeles area, and Kim Olsen explained the simulations of scenario earthquakes. Ned Field and Lucy Jones were both popular targets for the television cameras. SCEC's future Director, Tom Jordan, was also present to answer questions.

The scientists and staff of the Southern California Earthquake Center would like to thank everyone involved in the January 16th press conference for contributing to this important milestone in SCEC's history.

[For an overview of the Phase III report and technical resources, visit the SCEC Phase III web page.]

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