County of Los Angeles Fire Department
The coast of Los Angeles County is well known for its beautiful open beaches, scenic coastal cliffs and bluffs, popular marinas, the sweeping vistas from atop the Santa Monica Mountains, the Mediterranean charm of Catalina Island, and of course the surf and an ocean environment that draws people from around the world. Los Angeles County is home to two of the busiest ports in the world, and the coastal living is unmatched.
Naturally, living near the ocean has certain inherent risks, and one of them is the potential for tsunamis. Tsunamis are rare events, so you should not let this natural hazard reduce your enjoyment of the beach and ocean.
However, you should be aware of the dangers, and prepared to MOVE QUICKLY INLAND AND/OR TO HIGHER GROUND in the event a Tsunami Watch or Warning is issued, or if signs of a possible incoming tsunami are noticed (including strong ground shaking that knocks you off your feet, breaks windows, knocks objects off shelves, etc; the ocean receding or quickly rising; or other sudden unnatural behavior of the water).
As part of the Los Angeles County Tsunami Plan, the L.A. County Fire Department and other public safety agencies are prepared to issue warnings, assist in evacuations, and strategically deploy fire/rescue units when conditions or warnings from the West Coast Alaska Tsunami Warning Center indicate a potential tsunami situation. They are also working to develop more comprehensive public warning systems to ensure timely notification to all residents and visitors of potential tsunami conditions.
Your Los Angeles County Fire Department, other local fire departments and lifeguard agencies, and the County, State, and Federal Governments have also developed plans to immediately begin coordinated multi-agency search and rescue, firefighting, emergency medical, and hazardous material mitigation operations in the event that one or more tsunamis actually strike our coastline.
Working with tsunami experts from USC, Cal Tech, the California State Seismic Safety Commission, and other authorities, the Fire Department has developed a comprehensive approach to this rare but substantial natural hazard. One of the most important components of this plan is Public Education. If the citizens and visitors in Los Angeles County understand the hazards and the basic actions to be taken, we can greatly reduce the danger and prevent significant life loss.
What are Tsunamis?
A tsunami (pronounced soo-NAH-mee) is actually a series of traveling ocean waves of extremely long length generated primarily by earthquakes that disrupt the ocean floor, or earthquakes that trigger large underwater landslides. Oceanic volcanoes and even meteorite impact can also cause tsunamis, although these are rarer but equally dangerous.
Contrary to common perceptions, tsunamis are not simply large waves of the sort generated by normal oceanographic and weather conditions. Tsunamis are very different from wind-generated waves because of their ability to sweep ashore for great distances. While it is true that tsunamis may be quite large in height, the true danger is related to the mass of energy that propels them through the ocean at great speeds, and what happens when the tsunami waves reach the shore.
Tsunami waves are also distinguished from ordinary ocean waves by their great length between wave crests, often exceeding 60 miles in the deep ocean, and by the time between these crests (ranging from 10 minutes to one hour). As the waves reach the shallow water of the coastline, the waves slow down and the energy causes the water to pile up into walls of water that can tower 30 to 100 feet in height.
The first tsunamis wave is often followed by a series of additional waves, which complicates efforts to locate and rescue people who may not have escaped in time. For the fire department, lifeguards, law enforcement, and others with responsibility to conduct rescue and other emergency operations, the additional waves represent a constant danger to First Responders. Sometimes the secondary tsunami waves are much larger than the first. Responders cannot use the first tsunami “run up” line as the safety boundary because additional waves may run further inland than the first.
Once a tsunami impacts the shoreline, it behaves very much like a flash flood, tearing through large buildings, carrying other buildings away, sweeping automobiles and people away, and battering them with all the debris that the flood has picked up. Being in front of a tsunami is not much different than being in the path of a dam that has broken: You will be struck by a wall of water carrying trees, rocks, automobiles, boats, and construction debris.
Survivability for victims caught in a tsunami is quite low. Many victims of are beaten and battered by the debris, and then drown. The fortunate ones manage to climb high enough to avoid the main thrust of the current, or are deposited on high ground, or manage to grab branches and buildings and pull themselves from the water. Some are rescued by bystanders, but this is a rare instance because of the forces involved and the suddenness of the event.
THE BEST WAY TO SURVIVE A TUSNAMI IS TO EVACUATE TO A SAFE LOCATION BEFORE IT STRIKES.
Damaging tsunamis are rare but potentially catastrophic events that can potentially affect more than 1 million people along the coast of California. More than 80 tsunamis have been observed or recorded in California over the past 150 years. 9 of these caused minor damage in ports and harbors, 4 tsunamis caused fatalities, and 2 caused major damage.
Tsunamis have caused some of the most devastating catastrophes in history, including the 2004 Sumatra event that killed more than 200,000 people in 13 nations in Asia and Africa; the eruption of Krakatoa, which killed more than 30,000 people in Indonesia; the destruction of the Minoan civilization in what is now Greece; the series of tsunamis that destroyed much of Lisbon (Portugal), a massive earthquake and tsunami that killed untold numbers of coastal Pacific Northwest Indian tribes 300 years ago, the 1964 Good Friday Earthquake that devastated much of Anchorage (Alaska) and sent a tsunami that killed dozens of people in Crescent City, California, and others.
With more than one million people at risk in California, tsunami readiness is a critical issue for our state and Los Angeles County.
Tele-tsunamis (those originating far away but traveling through the deep ocean at more than 500 miles per hour) may strike Los Angeles County in as little as one to three hours, or perhaps up to twelve hours after the triggering event, depending on the distance from the source. Although tele-tsunamis can potentially be very large, their delayed arrival allows more time to evacuation people from threatened areas and move emergency equipment and personnel into strategic positions for rapid response to an actual tsunami impact.
Near-source tsunamis can be more dangerous in some cases, because they can strike within minutes of an earthquake or underwater landslide, and they can potentially be larger when they strike our coast because their energy has not had time to dissipate. Naturally, near-source tsunamis are a great concern because there is less time to evacuate, less time to position emergency units, and may even impact first responders attempting to warn and evacuate people on the coast, or responding to fires, building collapses, and other emergencies caused by the same large quakes that can cause tsunamis to be generated.
There may be no time to issue official warnings for near-source tsunamis, so it’s very important for the public to understand the critical actions to be taken in potential tsunami inundation zones in the event of a major local earthquake. In the most basic terms, if you feel strong, sustained ground shaking that makes things and people fall down, breaks windows, or causes other damage, IMMEDIATELY MOVE INLAND AND/ OR TO HIGHER GROUND, and let others know to do the same.
What are the Potential Tsunami Inundation Zones?
In most coastal areas of Los Angeles County, it’s only necessary to move several blocks inland from the beaches. This is because most of our beaches are upward-sloping, with significant elevation changes further inland from old sand dunes, and coastal cliffs and hills.
Tsunamis can be amplified by bays, harbors, lagoons, or rivers and flood control channels, which can funnel the water and send it further inland.
In places where the ground is flatter (and especially where amplification can occur from bays, harbors, lagoons, and rivers), it’s necessary to move further inland to escape the potential tsunami inundation zone. Examples are Venice, Marina Del Rey, Play Del Rey, Redondo Beach Harbor, Los Angeles and Long Beach Harbors, and the flat areas of Long Beach southward toward Seal Beach. In these places, people (especially those with trouble moving due to injuries, the elderly, etc) may be better off conducting “vertical evacuation” into upper floors of high rise buildings, apartment complexes, and hotels, when there is a potential NEAR-SOURCE TSUNAMI event.
Tsunami Inundation Area maps based on calculations for “worst case scenarios” have been produced for our coastlines by USC in cooperation with the California Office of Emergency Services and FEMA; and they will be distributed to the public in the near future.
What is Being Done to Prepare for Tsunami Emergencies?
Remember, THE BEST WAY TO SURVIVE A TUSNAMI IS TO EVACUATE TO A SAFE LOCATION BEFORE IT STRIKES.
Under direction from the Board of Supervisors, the County of Los Angeles Office of Emergency Management (OEM) is finalizing the countywide Tsunami Plan, which includes Tsunami Evacuation Plans for all the incorporated cities and the unincorporated areas along our coast. A County Tsunami Task Force is working to complete the Tsunami Plan and the related public education programs and emergency response protocols.
Tsunami Evacuation Plans are being developed along the coast, with Evacuation Route signs to be posted on the beaches, on the streets, in telephone books, and other prominent locations. A public education program is being developed for schools and institutions, and for the general population of the coastal zones. Evacuation shelters are being planned to shelter and feed people displaced during tsunami warnings or after actual tsunami impacts. Other forms of warning for the public are being investigated, with funds being requested to support these efforts.
What is the Fire Department’s Plan for Tsunamis?
The Los Angeles County Fire Department is finalizing its Tsunami Plan to support warning and evacuation of threatened populations, to strategically locate fire department and Lifeguard Division units in advance of tele-tsunamis, to conduct search and rescue, firefighting, emergency medical, and haz mat operations in the immediate aftermath of large coastal earthquakes that might trigger near-source tsunamis. And your Los Angeles County Fire Department is implementing its plan to respond immediately in the aftermath of an actual tsunami impact, including conducting simultaneous air/land/sea search and rescue operations to locate and save victims unable to escape the waves, treat them for injuries, and transport them to hospitals using helicopters, boats, ambulances, and other means. This is a 4-part plan, for the following situations:
Level l: Tsunami Watch - Issued for possible Tele-Tsunamis from Distant Places
Level ll: Tsunami Warning
- Issued for possible or confirmed Near-Source or Tele-Tsunami
Level lll: Local Earthquake 6.5 or Greater
–Offshore quakes 6.5 or greater that can cause tsunamis, or larger earthquakes onshore that can cause underwater landslides that result in tsunamis.
Level IV: Actual Tsunami Impact
The Fire Department’s plan includes the strategic deployment and use of the following types of resources in all potential tsunami inundation zones:
- Engine Companies (fire engines)
- Aerial Ladder Truck Companies
- Paramedic Squads
- Lifeguard Ground Rescue Units
- Baywatch Boats
- Helicopters staffed with specially trained rescuers
- Urban Search and Rescue Task Forces
- Swiftwater Rescue Teams
- Bulldozers and other Heavy Equipment
- Chief Officers for command and control
- Brush Fire Patrols (for better access in difficult-to-reach areas)
- Inflatable Rescue Boats
- Personal Rescue Watercraft
- Emergency Support Teams
- Incident Command Teams
- Regional, State and FEMA Urban Search and Rescue Task Forces
- Regional and State Swiftwater Rescue Task Forces
- Camp Crews for trained manpower
- Hazardous Materials Task Forces
- Mobile Lighting Units
- Mobile Air Units
- U.S. Navy Hovercraft units
- Other resources as needed
What are Tsunami Bulletins, Watches, and Warnings?
Tsunami Information Bulletin : Message issued by the West Coast Alaska Tsunami Warning Center (WCATWC) to advise public safety agencies of the occurrence of a major earthquake in the Pacific or near-Pacific area, with the evaluation that a potentially destructive Pacific-wide tsunami was not generated.
Tsunami Warning Bulletin : Warning message issued throughout the Pacific based on confirmation that a tsunami has been generated that poses a threat to the population in part or all of the Pacific coast regions. A Tsunami Warning will be followed by additional bulletins with updated information until it is cancelled.
Regional Tsunami Warning/Watch Bulletin: Message issued initially by West Coast Alaska Tsunami Warning Center (WCATWC) based only on seismic information to alert all participants of the possibility of a tsunami and advise them that a tsunami investigation is underway. Those areas that are within 0 to 3 hours from the estimated time of arrival of the first wave are placed in a Tsunami Warning status. Those areas within 3 to 6 hours are placed in a Tsunami Watch status. It will be followed by additional bulletins until it is either upgraded to a Pacific-wide Tsunami Warning or until it is cancelled.
What You Should Do
Be aware of the tsunami dangers, and have a personal plan if you live, work in, or visit potential tsunami inundation zones. Share this knowledge with your family, friends, and neighbors. Be aware of the local tsunami warning systems, as well as the signs of impending tsunami arrival. If you work in a tsunami-prone area, have a workplace evacuation plan the includes leaving the area in the event of a tsunami emergency.
- If you are in school and you hear there is a Tsunami Watch or Warning, follow the direction of teachers and other school officials.
- If you are at work and hear there is a Tsunami Watch, make sure all co-workers are aware of it, and make preparations to evacuate if the Watch is upgraded to a Warning.
- For Tsunamis Warnings, do not hesitate to evacuate potential tsunami inundation zones.
- If you are home and you hear there is a Tsunami Warning, make preparations to evacuate inland and/or to higher ground if it is upgraded to a Tsunami Warning.
- If you are at home or elsewhere in a potential tsunami inundation zone when a Tsunami Warning is issued, immediately begin evacuation inland and/or to higher ground. Move in an orderly, calm, and safe manner. If traffic is jammed, go on foot or by bicycle or other methods that won’t leave you trapped in your vehicle if a tsunami should strike. Follow the direction of local law enforcement, the fire department, and lifeguards.
- If you are on the beach or in a potential tsunami inundation zone you feel the earth shake violently or for a sustained period of time (and especially if it knocks object or people down, damages structures, breaks windows, etc), DO NOT WAIT for a Tsunami Watch or Warning, or any other warning signals from authorities. Since near-source tsunamis may strike in as little as 3 to 5 minutes, there may not be time to issue public warnings before impact. IMMEDIATELY evacuate to a safe zone (inland or higher ground, or vertical evacuation into high rise buildings or sturdy apartments or hotels). Stay away from rivers, flood control channels, harbors, marinas, and bays that can funnel the water from tsunamis.
- Multi-story, reinforced concrete residences, offices, and hotels are found in many of the low-lying areas of Los Angeles County. The upper floors can provide a safe refuge if you cannot move inland or to higher ground due to traffic, distance, disability, small children, etc.
- Homes and small buildings are not designed to withstand tsunami impacts or protect you from the water. Do not stay in these structures.
- If you are on a ship or boat, so not return to port if a Tsunami Warning has been issued. Even small tsunamis can cause rapid and drastic changes in current, water level, and other conditions. If there is time to move your boat or ship to a location known to be more than 400 meters deep, weigh the following considerations:
- Local harbors and ports are under control of a harbor authority, who will direct operations including evacuation. Be prepared to move in the event a forced movement of vessels is ordered.
- Be sure you have enough time to motor your vessel safely into deep water. Ports and marina escape routes may be blocked with vessel traffic, trapping you in a place you don't want to be if a tsunami strikes.
- Concurrent severe weather and rough seas could present an even greater hazard outside the harbor, in which case leaving your vessel in place and moving inland or to higher ground may be your safest option.