TSUNAMIS: A WAKEUP CALL FOR THE U.S., PART 1

BY LARRY COLLINS

December 26, 2004, will go down as one of the most deadly dates in modern history. More than 288,000 people in a dozen countries died, thousands of miles of shoreline were ravaged by tsunamis topping 80 feet in some places, and hundreds of villages and cities were severely damaged or totally wiped off the face of the earth as a result of the Sumatra earthquake and tsunami. Millions were left without adequate food, water, and shelter. As of this writing, the largest multinational relief response in history continues to provide life essentials for survivors spread across numerous remote areas of these countries.

In the immediate aftermath of the tsunami, U.S. military ships and aircraft were rapidly assigned to support the search, rescue, and humanitarian support operations in these areas. The United States and other nations established coalitions to assist the United Nations in coordinating the delivery of aid to those most in need. The U.S. Agency for International Development (Office of Foreign Disaster Assistance) dispatched the Los Angeles County (LA) Fire Department and the Fairfax County (VA) Fire/Rescue Department international USAR task forces to Sri Lanka and Sumatra to help with the humanitarian assistance efforts.

What is disturbing is that the people in the nations around the Indian Ocean received virtually no warning concerning the impending disaster. Many might have been able to evacuate safely had they received sufficient warning.

The Sumatra quake and tsunami disaster should serve as a giant red flag, a wakeup call for fire and rescue and other government agencies in places where tsunamis could result from nearby and faraway causes. Today, many places on the U.S. coast are vulnerable to tsunamis, yet the current “on-the-ground” tsunami warning mechanisms will provide no or little more warning than that given to the victims of the Sumatra event.

Although the two U.S. Tsunami Warning Centers will dutifully issue alerts and warnings of potential tsunami events threatening the populations of exposed nations, only a few state and local governments have fully intact systems capable of translating those warnings into effective and timely action “on the ground.” As of this writing, relatively few fire, police, and lifeguard agencies in vulnerable coastal communities have implemented formal protocols for translating tsunami warnings into plans for effective evacuation, resource deployment, and post-tsunami search and rescue plans.

Some of these gaps in the warning and response system were highlighted just six months after the Asian tsunami calamity, when on June 14, 2005, a 7.2 earthquake occurred off the coast of Northern California. Within minutes, the West Coast and Alaska Tsunami Warning Center (WCATWC) issued a tsunami warning for the entire West Coast from Vancouver Island (Canada) to the Mexico-California border.

The June 14 tsunami warning set off a flurry of conflicting interpretations and decisions among agencies that had not yet established and implemented formal protocols for reacting to tsunami watches and tsunami warnings (each of which should, by rights, result in a series of actions and preparations in communities vulnerable to tsunami inundation). Some of the communications trees were not activated, or there were significant gaps in notifications.

In some cases on June 14, safety officials received their first word of a potential tsunami heading their way because they happened to be watching television and the news media picked up on the warning before it came through the public safety system. One official was alerted when his neighbor, who was watching television, called him. In other cases, critical teletype messages from at least one state warning center were picked up, scanned, and treated as routine by well-meaning (but misinformed) personnel, who in at least one case stuffed the warning message into a supervisor’s In box, thereby breaking a chain of notification that should have continued immediately and nonstop.

These gaps in the system were predictable and a source of concern for people who understand that the threat of lethal tsunami strikes (both near-source and distant-source) is very real on the West Coast of the United States, and even along the Atlantic Coast. Yet, in too many places, elected officials and public safety administrations have failed to take the emerging tsunami threat seriously and didn’t see the need to develop, establish, and test protocols for rapid and effective reaction to teletsunamis (those originating from distant sources).

Even fewer officials seem to recognize-much less address-the emerging threat of near-source tsunamis that can strike shore just moments after large earthquakes or submarine landslides. This is truly a “worst-case scenario” waiting to happen. Hopefully, the Sumatra calamity (and the June 14 event) would provide the impetus to get this done before the United States experiences a truly disastrous tsunami impact.

Fortunately, some state, regional, and local officials and responders have taken the tsunami threat seriously. The Pacific Northwest is particularly notable for the extensive tsunami planning and preparation that will certainly save lives should a tsunami occur. California, whose northern coasts traditionally were considered to be the most likely zones to be endangered by tsunamis, is being confronted with relatively new information indicating that lethal tsunamis can occur within minutes of earthquakes generated by offshore thrust faults and even onshore quakes that cause submarine landslides. In places like Ventura, Orange, Los Angeles, and San Diego counties, local and regional tsunami warning, evacuation, and response plans are in place or are being developed for rapid implementation.

In the aftermath of the Asian tsunamis, the United States has stepped up efforts to expand its tsunami warning detection and warning systems to protect all of its coastlines. The federal government plans to spend at least $37 million over the next two years to widen the warning net to include the Atlantic and Caribbean coasts.

And now, around the Indian Ocean, the parts of the Pacific, Atlantic, and the Caribbean seas, emergency planners, government officials, and scientists are making urgent plans to install new networks of sensors to detect tsunamis and implement emergency plans for conducting evacuations and post-tsunami response. But experts know that it will take more than these measures in places where millions of people had never experienced a tsunami as a threat.

BLUEPRINT OF A CALAMITY

On Christmas Day, 2004, at the Pacific Tsunami Warning Center in Hawaii, Andrew Hirshorn and Stuart Weinstein were alerted by their pagers (by an automated system) that a major earthquake had occurred somewhere in the world. It quickly became evident that an earthquake of a magnitude of at least 8 had occurred in the Indian Ocean off the north coast of Sumatra, outside the jurisdiction of the Pacific Warning Center.

Hirshorn and Weinstein, being somewhat unfamiliar with the tsunami hazards in the Indian Ocean because their official mission was limited basically to the Ring of Fire (Pacific Rim), were somewhat misled by the relative lack of hard data on historic tsunamis in that region. Plus, they had no contact with authorities in South Asia, which does not have a tsunami warning center or any other official warning system for such an event. So they transmitted the following communiqué through an automated e-mail and FAX system that distributes the information to colleagues and government agencies around the Pacific Rim:

    Tsunami Bulletin Number 001
    pacific tsunami warning center/noaa/nws
issued at 0114z 26 dec 2004.

    This bulletin is for all areas of the pacific basin except alaska-british columbia-washington-oregon-california. this message is for information only. There is no tsunami warning or watch in effect. An earthquake has occurred with these preliminary parameters: origin time-0059z 26 dec 2004; coordinates-3.4 north 95.7 east; location­-off the coast of northern sumatra; magnitude-8.0.

    Evaluation: This earthquake is located outside the pacific. No destructive tsunami threat exists based on historical earthquake and tsunami data.

At the time this communiqué was being sent, a series of large tsunamis, which had traveled outward at least 100 miles, were fast approaching the shores of Indonesia. The waves began wiping out villages along the northern coast of Sumatra, and then they obliterated much of the city of Banda Aceh, population 150,000, killing perhaps 90,000 people there. At approximately 8 a.m. local time, the Indian Air Force Base on the island of Car Nicobar was hit by tsunamis, estimated by survivors to be from 30 to 50 feet high. At least 102 Air Force personnel were swept to sea as a Mayday was broadcast over a military frequency. The Air Force mainland facilities did not pick up on the Mayday, but it was heard by controllers at the Madras airport, who relayed the information to Air Force officials. They dispatched transport planes to check on the status of the airbase. The problem was, Air Force officials failed to notify civilian authorities that a potential tsunami had struck. The tsunami was now heading toward the Indian mainland; still, no warnings had been issued to the public or civilian authorities there.

Back in Hawaii, Tsunami Warning Center Director Charles McCreery had joined Weinstein and Hirshorn, and information coming in from the U.S. Geological Survey was now indicating that the quake was actually 8.5. Because of the marked increase in the size of the earthquake, they agreed that there was a higher possibility that a tsunami had been generated. Therefore, McCreery issued the following advisory to the Pacific Warning Center recipients:

    No destructive tsunami threat exists for the Pacific basin based on historical earthquake and tsunami data. There is the possibility of a tsunami near the epicenter.

Unfortunately, even this information had no way of reaching authorities in Southern Asia. The Pacific Warning Center didn’t even have phone numbers for colleagues in the Indian Ocean region. By now, however, tens of thousands of people had been killed by tsunamis in Indonesia, and it was already too late for tens of thousands more.

A PRIMER ON TSUNAMIS

Even though tsunamis have long inspired fear among civilizations in parts of Japan, Hawaii, the South Pacific Islands, Alaska, and now in South Asia and Africa, whose coastlines border the Indian Ocean, where the December 26 tsunami originated, truly damaging tsunamis have been relatively rare in most coastal areas. Perhaps it is precisely this “low-frequency, high-casualty” aspect of tsunamis that makes it difficult to convince people living and working in vulnerable coastal areas that they should be prepared for them.

To the casual observer, so-called “tidal waves” or “harbor waves” are relegated to the realm of the highly improbable. Prior to the South Asia tsunami, perhaps the most photographed disaster in history, the closest most of us have come to experiencing a tsunami was viewing the 1960s movies Krakatoa East of Java or Deep Impact. Now, most of us have seen photos and videotape of the Indian Ocean tsunamis approaching the coastlines of various nations and coming onto land like freight trains.

Many can now envision what those who’ve studied tsunamis have been trying to tell them for years: When a tsunami impacts the shoreline, it often behaves like a flash flood (or, perhaps more closely, a dam failure). Instead of waves that simply break on the beach, tsunamis have the entire mass of the ocean behind them. When they strike land, they are miles-long walls of water carrying boats, debris from crushed buildings, automobiles, and people picked up as they roll across the land. When they reach their apex in sloped areas, they reverse course and rush back to sea, carrying everything they picked up with them.

Despite the potential for huge losses of life and the destruction of coastal cities, tsunamis remain a little-understood phenomenon to many firefighters and fire/rescue agency leaders. Tsunamis (sometimes called seismic sea waves) are often low on the priority list of public safety agencies along both coasts, even in some zones long identified as being vulnerable to their effects.

In nations like Japan, where entire fire departments have nearly been decimated in this century by tsunamis that struck in the night during post-earthquake firefighting and rescue operations, there is widespread appreciation for the lethal effects of these events. The challenge is to instill the same level of appreciation in vulnerable coastal areas outside Japan, before a tsunami needlessly kills large numbers of firefighters and rescuers. We must also highlight new discoveries to encourage fire/rescue agencies in vulnerable areas to develop realistic plans to address this unusual but very lethal hazard.

Emerging research indicates many cities on the West Coast of the United States previously thought to be invulnerable to “near-source” tsunamis are in fact prone to large tsunamis that can wipe out large coastal tracts and kill tens of thousands of people within minutes of precipitating events like offshore (and even onshore) earthquakes and underwater landslides. For firefighters and chief officers, this new information indicates a previously unrecognized danger when assessing post-earthquake damage along the coastlines and while attempting to suppress fire, rescue trapped victims in collapsed structures, treat the injured, and other post-earthquake emergency operations. The danger may come in the form of one or more seismic sea waves (sometimes that second or third tsunami is larger than the first) that can strike with little warning within minutes of an earthquake or underwater landslide and take the lives of firefighters and rescuers who responded to the damaged areas.

Tsunamis are very different (and hence more dangerous) from wind-driven waves with respect to their inertia and their ability to sweep ashore for great distances. It’s true that tsunamis may be quite high, but the true danger is related to the mass of energy that propels them through the ocean at great speeds. This “thrust” is generally caused by significant vertical movement of large blocks of the earth’s crust during earthquakes, by large underwater landslides, or both.

When such a mass of waterborne energy strikes the coast, it may suddenly raise the level of the sea and drive walls of water far inland, creating a sort of flash flood that can pick up ships and large buildings and carry them inland. Topographic features of coastal zones such as bays, inlets, and river mouths can multiply this effect.

THE MISUNDERSTOOD THREAT OF “NEAR-SOURCE” TSUNAMIS

The Asian tsunami clearly demonstrated the lethal danger of near-source tsunamis. In places like Bandhe Ache (Indonesia), the tsunamis were preceded by several minutes of strong shaking, which should have been the one certain and clear warning to coastal populations that deadly tsunamis might be on the way. Within 15 minutes, waves in excess of 80 feet were bearing down on coastal cities and villages in Northern Sumatra. Could the same thing happen in the United States? The answer is Yes. But many people in vulnerable areas aren’t aware of this deadly potential, and even some public safety officials seem unaware of how bad it could be and what to do about near-source tsunamis. Part of the reason is that seismologists and others who study earthquakes and tsunamis believed it would be impossible to experience near-source tsunamis.

With the exception of Alaska, Washington State, Oregon, and Northern California-places long known to be at risk from near-source tsunamis originating in the subduction zones on which they lie2-the threat of tsunamis in most U.S. coastal areas was traditionally considered to be related to distant sources, thereby making it possible to provide hours of warning. In fact, the National Tsunami Warning Center was established with the primary mission of providing timely warning of such far-source events, and state and local officials have developed elaborate evacuation plans for these events.

Likewise, earth scientists have long been assuring fire/rescue officials in Southern California that the true threat of tsunamis there rests with distant sources like Hawaii, Peru, Japan, and the Aleutian Islands. For years, these officials were told that the potential for near-source tsunamis is incredibly low, almost too low to be concerned about. The low incidence of damaging tsunamis during the past century contributed to a false sense of security in Southern California and seemed to support the position of the earth scientists who dismissed concerns about near-source tsunamis. Consequently, there was little urgency to develop elaborate tsunami evacuation and response plans for near-source events, a potentially devastating oversight if a near-source tsunami were caused by offshore thrust faults or submarine landslides we now know are possible in Southern California.

As an example, the standard fire department plans in Southern California call for fire/rescue units to respond into their jurisdictional areas to conduct “windshield surveys,” rapid visual and physical assessments of damage levels and major problems (or lack thereof) while these units roll “Code R” through the streets on predetermined routes to check the status of the most obvious life-loss hazards. Naturally, these plans also call for fire/rescue resources to be moved into heavily damaged areas once the areas in greatest need of firefighting, EMS, haz-mat, and USAR assistance have been determined. Typically, these plans haven’t taken into consideration the potential for near-source tsunamis to strike heavily damaged coastal zones within minutes of significant earthquakes. In addition, the potential for underwater landslides has almost universally been unknown or ignored.

These actions will place fire/rescue personnel in immediate danger if a near-source tsunami should catch them by surprise by striking during the early and most dangerous phase of post-earthquake operations. The danger is that fire departments and rescue teams responding to fires, collapses, casualties, and hazardous-materials releases in quake-damaged coastal zones may be wiped out by surprise tsunamis.

This exact phenomenon occurred when a major earthquake struck a major Japanese island in the late 1990s. As residents evacuated the coastline for high ground in the dark of night, the city lit up with flames from various quake-spawned fires. As residents and film crews watched in disbelief from the hills, a black wave of water swept into the city below, destroying burning buildings and fire engines alike. Several more tsunamis followed the first, wiping out large sections of the city.

That approach to post-earthquake response and damage assessment must be reconsidered because of the newly discovered threat of near-source tsunamis along the middle and Southern California coasts (and yet another surprise location: Lake Tahoe, high in the Sierra Nevada Mountains, more than 150 miles from the ocean).3 To understand why near-source tsunamis should be of serious concern to fire/rescue authorities, one need look no further than the history-drenched nation of Turkey.

1999 TURKISH QUAKE RESPONSE

A rarely discussed effect of the deadly earthquake that struck the Izmit region of Turkey in 1999 was the devastation caused by incursion of the Sea of Maramar, which left portions of several coastal cities under water, quite literally sunk beneath the waves. Dramatic land subsidence accompanied by moderate tsunamis occurred during the 7.4 main shock, walls of water washing across city streets just as some people emerged from their homes in the predawn darkness to escape collapsed or damaged buildings.

In some places, the land simply sunk beneath the sea during the quake, taking with it everything, including people in homes and other buildings. Today, parts of the city can still be seen beneath the water, practically intact.

Elsewhere, tsunamis rushed inland like a flash flood in the dark. Even though the tsunamis appeared to have been just a couple of meters high, they carried automobiles, boats, and debris, just as we have seen in the most recent Asian catastrophe. As each wave receded, buildings and people (some-including at least two police officers-still inside their automobiles) were washed into the sea. It was a cruel blow, piling more misery on a population that had just been struck by one of the worst natural calamities of the century.

The land subsidence and tsunamis complicated search and rescue operations by denying or delaying access to firefighters and rescue teams. Victims who might otherwise have survived until rescue teams reached them simply drowned as seawater swept into quake-damaged buildings. Some (including those in vehicles that sank with the land) were discovered on the sea floor by rescue divers in the days following the quake. It was mute evidence of the power of tsunami-related events. Could it happen in the United States? Yes, say many experts.

NEWLY DISCOVERED TSUNAMI PROBLEM SHAKES UP SOUTHERN CALIFORNIA

The potential for both teletsunamis and near-source tsunamis along the northern reaches of the West Coast has long been recognized. A few hours after the 1964 Good Friday earthquake struck Fairbanks, Alaska, remnants of quake-generated tsunamis killed people in Crescent City (northern California) and caused serious property damage in parts of southern California. Throughout the geologic history of the Americas, the northern West Coast has been the site of tsunamis originating from earthquakes and underwater landslides in distant spots on the planet, as well as in its own backyard.

In contrast, seismologists and geologists were for decades under the mistaken impression that earthquake faults in middle and southern California were of the “strike-slip” variety.4

Thus, Southern Californians generally assumed that locally generated tsunamis5 were a nonissue because the conditions precipitating seismic sea waves had never been found south of the Cascadia region. Until recently, that remained the mantra of many seismologists and earth scientists. Now, based on emerging research, it appears this view was mistaken (and perhaps overly optimistic).

In 1992 the Cape Mendocino earthquake surprised seismologists by generating a small tsunami that struck the Northern California coastline within minutes of the quake. It was the first near-source tsunami to be detected south of the Oregon border. This was a region thought to be invulnerable to near-source tsunamis. Even though the tsunami was rather small, it indicated the potential for very large tsunamis to strike the coastline within minutes under certain conditions. The Cape Mendocino event prompted a reevaluation of near-source tsunami hazards in California, one that has yielded surprising results.

However, before the Cape Mendocino quake studies could be completed, another surprise-this one far larger and more troubling-occurred in the form of the disastrous Northridge earthquake in 1994. The Northridge quake, which killed nearly 70 people, had its origins in a previously unidentified “hidden thrust fault.” Scientists couldn’t find the ground fault rupture from Northridge and began to surmise that the event occurred on a thrust fault deep beneath the surface. This was eventually verified. Including the Coalinga (Central California) earthquake in the early 1980s, the state had suffered two damaging quakes on previously unidentified thrust faults. It was clear that there was a new danger afoot: If two deadly quakes occurred on hidden thrust faults within a decade, how many other hidden faults were out there?

Armed with this question, scientists began a quest to quantify the threat posed by thrust faults (hidden and otherwise). In the intervening years, a number of previously unknown thrust faults have been identified in California. Most disturbing, a number of them have been found beneath the waters of the Pacific, off the shores of Los Angeles, Ventura, and Santa Barbara counties.

Scientists now recognize that these faults are capable of generating large tsunamis that can make landfall within minutes or even seconds. In the case of Santa Barbara, where computer modeling has been completed by a team headed by Dr. Costas Synolakis of the University of Southern California’s School of Engineering, localized tsunamis approaching 36 feet high are considered possible.

Researchers have also discovered evidence that large underwater landslides in deep offshore canyons pose a major tsunami risk even before earthquakes are factored in. Evidence of past tsunamis from this cause has been found from Santa Barbara to Long Beach and Orange County. The recent Santa Barbara studies (commissioned by the California Office of Emergency Services, or OES) found evidence of a very large crack in the offshore coastal shelf, which appears capable of separating to cause a huge underwater landslide, which in turn would generate large tsunamis that could strike the coastline within seconds or minutes.

As new evidence continues to be uncovered, it’s fast becoming clear that the previously held assumptions were false. As a result, yet another hazard is being added to the list of things for which fire/rescue agencies must be prepared: devastation of densely populated coastal zones by large tsunamis striking with little or no warning, sometimes in the immediate aftermath of a catastrophic earthquake.

NEW THEORIES ABOUT TSUNAMI THREAT

New theories hold that populated coastal areas of Los Angeles County and other parts of Southern California are at moderate to high risk from large tsunamis generated by local earthquakes, as well as from local underwater landslides. According to Dr. Synolakis’ team and other researchers, the potential for heavy damage and loss of life from these events is significant. Perhaps most disturbing are new findings that local offshore faults are capable of generating large tsunamis that can strike the coast of Los Angeles County within as little as a few minutes, leaving little time for warnings or evacuation.

The OES/USC studies indicate that places like critical areas as Marina Del Rey, Malibu, Long Beach, and other densely populated coastal zones are at extreme risk for heavy damage and life loss in the event of tsunamis. Dr. Synolakis and his associates have determined that even moderate-sized tsunamis can propagate far into Marina Del Rey, up Ballona Creek, and up Malibu Creek (via Malibu Lagoon and directly through parts of Malibu Colony). They have uncovered evidence that these and other vulnerable coastal sites can suffer huge loss of life and damage to property. The message for fire/rescue personnel is clear: If tsunamis are preceded by earthquakes that cause fires, structural collapses, haz-mat releases, and injuries along the coast, emergency responders will be exposed to significant hazards that they may not anticipate.

This is surprising information in Southern California, where scientists have for decades assured emergency planners that locally generated tsunamis are not a credible threat. As a result of years of assurances that tsunamis were low-level risks, few Southern California municipalities have developed warning systems or emergency response plans for locally generated tsunamis.6

Consider the example of Marina Del Rey, one of the largest private yacht basins on the West Coast, nestled between Santa Monica and Los Angeles International Airport. Dr. Synolakis’s current studies demonstrate that a large portion of this coastal community would be inundated by even a “moderate” six-foot tsunami and sea rise and that the projected “maximum tsunami” for that area, up to 44 feet in height, would wash over an area that extends three miles inland and encompasses around 50,000 people.

Imagine 44-foot tsunamis striking Marina Del Rey, a densely populated coastal zone with thousands of boat slips, most of which are occupied (and many occupied by owners who live aboard). The waves would approach the shoreline, capsizing or picking up ships and boats unfortunate enough to be close to shore. They would then wash over the breakwater, carrying boats, yachts, and floating docks as they move across the water. On striking the inland edge of the marina, this “flash flood” wave would come ashore, adding automobiles, buildings, and people to its debris load as it moves onto land. Then these long, wide waves would continue inland, wiping out entire neighborhoods far inland of the beaches, leaving behind a scene not dissimilar to what we saw in Ache and Bande Ache. Part of the wave would run even farther up Ballona Creek, a wide channel that normally drains flood waters to the ocean, causing further damage in adjacent neighborhoods.

The impact area could be the target of multiple waves, some larger than the first, which could endanger rescuers for hours afterward. Aftershocks could result in repeated tsunamis for hours after the main shock, perhaps even up to 24 hours later.

According to several researchers, similar effects could occur at coastal inlets and tributaries like Malibu Creek and other populated coastal zones. River inlets, creek drainages, swamps, marinas, and manmade waterways are particularly vulnerable to tsunami action because they tend to propagate large waves further inland. Low, flat areas are also natural targets. For this reason, some of the most valuable property on the West Coast may be Ground Zero for deadly tsunamis.

PROBLEMS FOR FIREFIGHTERS

For victims (and firefighters and other responders) caught in the inundation zone of a tsunami, the overall effect of the incoming and outgoing waves would be like that of multiple flash floods that completely (and repeatedly) reverse course. It would be bad enough if tsunamis were the only problem about which to be concerned. But, for responders living and working in seismically active areas, it could get much, much worse. In the aftermath of a catastrophic earthquake, one or more tsunami impacts might multiply the search, firefighting, and rescue problems.

In Part 2, we will examine how to prepare for teletsunamis and near-source tsunamis and how it is being done in densely populated coastal zones where officials have been proactive in developing response plans for these potential disasters.

Endnotes

1. Paul Watson, Barbara Demick, Richard Fausset, “Chronicle of a Disaster: A Tremor, Then a Sigh of Relief, Before the Cataclysm Rushed In,” Los Angeles Times, Jan. 2, 2005.

2. It is now known that parts of the coast of Alaska and Washington have dropped as much as 30 feet in an instant during subduction zone earthquakes that occurred before written records were kept. Scientists have concluded that the areas around Seattle and other densely populated coastal zones are vulnerable to this type of geologic effect, which would flood the land with a sudden and massive surge of ocean water filling the newly lowered landscape. Although this is not a tsunami in the traditional sense, the effects would be equally as devastating (if not worse). In addition to this risk, the Alaska and Washington state coastlines are also prone to “traditional” near-source and far-source tsunamis.

3. Recently, scientists announced the discovery of two thrust faults that run the length of the bottom of Lake Tahoe. They estimate that an earthquake on either fault may cause tsunami-like waves exceeding 30 feet in height. Such an event might kill thousands of people and wipe out dozens of towns that ring the lake.

4. Generally speaking, strike-slip faults aren’t directly associated with tsunamis because when they rupture, one side moves past the other “sideways,” without a significant vertical component. This is the opposite of “thrust faults,” where one side is suddenly thrust upward in relation to the other when they rupture (almost assuredly generating one or more tsunamis in the process).

5. Because they’re caused by events close to land (and because they travel at the speed of a jet airplane), near-source tsunamis are especially dangerous because there is little warning and little time to escape the shoreward-rushing seas that accompany them.

6. The Ventura County (CA) Fire Department has for two decades kept a tsunami response plan in effect, and the Lifeguard Division of the County of Los Angeles Fire Department has a plan for distant-source tsunamis, which are generally preceded by hours with warnings from the Pacific Tsunami Warning Center.

LARRY COLLINS is a 25-year member of the Los Angeles (CA) County Fire Department (LACoFD). He is a captain, USAR specialist, and paramedic assigned to USAR Task Force 103, an LACoFD rescue company. He is assigned to Tsunami Planning committees for the LACoFD and the County of Los Angeles. He is a search team manager for the LACoFD’s FEMA/OFDA USAR Task Force for domestic and international disaster response and as a USAR specialist on the “Red” FEMA US&R Joint Management Team, with deployments to the 9-11 attack on the Pentagon, the Oklahoma City bombing, the 2004 Florida hurricanes, and several national security events. He is author of the three-part book series Technical Rescue (Fire Engineering Books and Videos, Part 1, 2004; Part 2, 2005)

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