Brought to you by the San Francisco Department of Emergency Management

Treasure Island Tsunami Education

Tsunami Open House Join the San Francisco Department of Emergency Management (SFDEM) and Treasure Island Development Authority (TIDA) to learn about Treasure Island’s tsunami risks, public alert and warning, and how to protect your family, friends, and community through awareness and preparedness. This event will include informational posters and opportunities to engage SFDEM, State of California Office of Emergency Services (CalOES) and TIDA staff.

May 26, 2016 5:30-8:00 pm Ship Shape Community Center, 850 Avenue I, Bldg 497, Treasure Island, SF 94130 Who’s invited: All Treasure Island community members

Sfdem.org megan.stephenson@sfgov.org

Brought to you by the San Francisco Department of Emergency Management

Treasure Island Tsunami Open House

Thanks for joining us at the open house. Below is some helpful information on tsunamis from the San Francisco Department of Emergency Management.

Frequently Asked Questions

Q: What is a tsunami and can it happen here? A: A tsunami is a series of ocean waves caused by a displacement of the sea floor, typically caused by a large earthquake or by a landslide into or under the water surface. Tsunamis may cause dangerous coastal flooding with strong currents that may last for many hours. Tsunamis are a low probability event for San Francisco but can have severe consequences. This why we prepare for them. A distant source tsunami with 4 to 15 hours of warning is a more likely scenario than near source tsunami with less than 15 minutes of warning. Q: How can I prepare for a tsunami? A: Prepare yourself by gathering supplies, planning ahead, and getting connected with your community.

Pack a go-bag and store it somewhere quickly accessible. Your bag should have things like water, extra clothes, and first aid kit. Visit http://sf-fire.org/more-preparedness-information for more information. When you have to act fast, having a plan that you’ve practiced is the key. Start a plan by visiting www.SF72.org/plan.

Brought to you by the San Francisco Department of Emergency Management

Get to know your neighbors and look out for each other now. Find out who can help and who needs help in an emergency. Consider joining San Francisco’s Neighborhood Emergency Response Team (NERT) by visiting www.sfgov.org/sfnert. Q: How do I know if a tsunami is on the way and what do I do? A: Know the warning signs: Strong ground shaking, a loud ocean roar, or the water receding are all nature’s warnings. If you’re by the water move inland and higher ground immediately. If there is time (a distant source tsunami) we will send out alerts and instructions. AlertSF is one way the City will send alerts. Sign up by texting the word AlertSF to the number 888-777 or by visiting www.alertsf.org. Another way is Outdoor Public Warning System is designed to alert residents and visitors of San Francisco about possible danger.

Q: What will the City do in the event of a tsunami? A: Emergency responders will send alerts and help facilitate evacuations if time and safety permits. If you can self-evacuate and can help someone else please do so. If you need or know someone that needs assistance call 9-1-1.

Q: What does this mean for Treasure Island? A: Moving away from a tsunami on Treasure Island means driving on to the Bay Bridge towards San Francisco. The Oakland touchdown-area of the bridge is in the tsunami flood zone. If you self-evacuate using your own vehicle please pick up your neighbors. Carpooling is essential since there is limited vehicle access to the Bay Bridge.

Q: Can I walk to Yerba Buena Island? A: Yerba Buena Island offers sufficient high ground, however, there currently is no pedestrian walkway from Treasure Island. Walking to Yerba Buena Island means traveling on the same road being used by vehicles for evacuation.

In the future, a bicycle path will connect Treasure Island to the eastern span of the Bay Bridge. A pedestrian walkway to Yerba Buena Island will also be established. Both may offer a safer alternative to walking on the roadway.

Get Connected

Connect to text alerts on ALERTSF, by texting to 888-777 the word “alertsf” with no quotes and case doesn’t matter. Check out SF72.ORG for helpful preparedness information. Call 911 for help for any emergency.

How to Survive

a Tsunami

www.calema.ca.gov

IF YOU FEEL A STRONG EARTHQUAKE WHILE

NEAR THE COAST:

1. PROTECT yourself during the earthquake

• If indoors, DROP under a sturdy table or object, COVER your head and neck and

HOLD ON.

• If outdoors, move to a clear area if you can safely do so - away from trees, beach cliffs, signs and other hazards - and drop* to the ground.

* If you have mobility impairments that prevent you from getting up on your own, do not drop to the ground but do cover your head and neck and hold on.

2. MOVE to High Ground • As soon as it is safe to move, go to higher ground. DO NOT WAIT for an official tsunami warning.

• Avoid downed power lines and weakened overpasses.

• If you are outside of a tsunami hazard zone, stay where you are.

3. STAY There

• Remain on high ground. Waves from a tsunami may arrive for eight hours or longer.

• Return to the coast only when officials have announced that it is safe to do so.

COVERDROP

This document was prepared under a grant from FEMA’s Grant Program Directorate, U.S. Department of Home-land Security. Points of view or opinions expressed in this document are those of the authors and do not necessarily rep-resent the official position or policies of FEMA’s Grant Programs Directorate or the U.S. Department of Homeland Security. 7_09

THINGS YOU SHOULD KNOW ABOUT TSUNAMIS

• A tsunami is a series of waves or surges most commonly caused by an earthquake beneath the sea floor.

• An unusual lowering of ocean water, exposing the sea floor, is a warning of a tsunami or other large wave. This “draw back” means the water will surge back strongly.

• Beaches, lagoons, bays, estuaries, tidal flats and river mouths are the most dangerous places to be. It is rare for a tsunami to penetrate more than a mile inland.

• Tsunami waves are unlike normal coastal waves. Tsunamis are more like a river in flood or a sloping mountain of water and filled with debris.

• Tsunamis cannot be surfed. They have no face for a surfboard to dig into and are usually filled with debris.

• Large tsunamis may reach heights of twenty to fifty feet along the coast and even higher in a few locales. The first tsunami surge is not the highest and the largest surge may occur hours after the first wave. It is not possible to predict how many surges or how much time will elapse between waves be for a particular tsunami. • The entire California Coast is vulnerable to tsunamis. The Crescent City Harbor on California’s North Coast suffered significant tsunami damage as recently as 2006. A dozen people were killed in California following the 1964 Alaska earthquake.

ADDITIONAL RESOURCES:About tsunamis: http://wcatwc.arh.noaa.gov/

Identifying natural hazards in your neighborhoodwww.myhazards.calema.ca.gov

Preparing for earthquakes and tsunamiswww.earthquakecountry.org

The California Geological Survey www.consrv.ca.gov/cgs

Or contact your county Office of Emergency Services.

Prepared by: California Emergency Management Agency Earthquake and Tsunami Program 3650 Schriever Avenue, Mather, CA 95655 (916) 845-8510Concept and partial text from the Redwood Coast Tsunami Work Group.

HOLD ON

• Protect yourself during the earthquake

• Move to high ground or inland as soon as you can

• Stay there

Prepared by:

DROP!

1

COVER!

2

HOLD ON!

3

TWO WAYS TO FIND OUT IF A TSUNAMI MAY BE COMING

1. NATURAL WARNINGStrong ground shaking, a loud ocean roar, or the water receding unusually far exposing the sea floor are all nature’s warnings that a tsunami may be coming. If you observe any of these warning signs, immediately go to higher ground or inland. A tsunami may arrive within minutes and may last for eight hours or longer. Stay away from coastal areas until officials announce that it is safe to return.

WHEN SHOULD I EVACUATE?

Evacuation should not be automatic. Before evacuating you should determine if you are in a hazard zone and consider possible hazards that may exist along your evacuation route.

• Know if you live, work, or play in a tsunami hazard zone.

• COUNT how long the earthquake lasts. If you feel more than 20 seconds of very strong ground shaking and are in a tsunami hazard zone, evacuate as soon as it is safe to do so.

• If you are on the beach or in a harbor and feel an earthquake—no matter how small—immediately move inland or to high ground.

• GO ON FOOT. Roads and bridges may be damaged. • Avoid downed power lines.

• If evacuation is impossible, go to the third or higher floor of a sturdy building or climb a tree. This should only be used as a last resort.

• If you hear that a tsunami warning has been issued but did not feel an earthquake, get more information. Listen to the radio, television or other information sources and follow the instructions of emergency personnel.

• If you are outside of a tsunami hazard zone, take no action. You are safer staying where you are.

PREPARE NOWHow you prepare will affect how you recover. And being prepared for earthquakes and tsunamis prepares you for all kinds of disasters.

• Know if you live, work, or play in a tsunami hazard zone.

• Learn what the recommended tsunami evacuation routes are in your city, county and region. Identify safety zone(s) near you, and decide on your primary and secondary evacuation routes.

• If you live or work in a tsunami hazard zone get a NOAA weather radio with the public alert feature for your home and office. It will alert you even if turned off.

• Assemble a small evacuation kit with essential documents, medications, a flashlight, a portable NOAA weather radio and batteries, water, snacks and warm clothes. Include a silver “space blanket” in your kit – it can be used to signal your location to air search teams. Keep your evacuation kit by the door so you can “grab & go”.

• Walk your route – consider what you would do at night or in stormy weather. • Make a reunification plan with your loved ones. Decide when and where you will meet if you are separated, and what out of state relative or friend you will call if it is not possible to meet at your pre- designated reunification spot. • Discuss plans with family, coworkers and neighbors.

• Make plans for how to address any functional needs or disabilities you might have. If you need help evacuating, prearrange assistance from neighbors including transport of mobility devices and durable medical equipment. If you are mobility impaired, account for the extra time that you may need. • Decide on the best strategy for protecting your pets.

• Prepare to be on your own for several days or longer. • Consider joining your Community Emergency Response Team (www.csc.ca.gov/cc/cert.asp)

WHERE SHOULD I GO?All California coastal counties have tsunami hazard guidance maps and are in the process of posting tsunami hazard zone signs. These signs and maps will show you what areas are safe and what areas may be at risk. Use them to guide you to a safe area. Natural and official warnings are equally important.

Respond to whichever comes first.

If no maps or signs are available, go to an area 100 feet above sea level or two miles inland, away from the coast. If you cannot get this far, go as high as possible. Every foot inland or upwards can make a difference.

2. OFFICIAL WARNING You may hear that a Tsunami Warning has been issued. Tsunami Warnings might come via radio, television, telephone, text message, door-to-door contact by emergency responders, NOAA weather radios, or in some cases by outdoor sirens. Move away from the beach and seek more information on local radio or television stations. Follow the directions of emergency personnel who may request you to evacuate beaches and low-lying coastal areas. Use your phone only for life-threatening emergencies.

CALIFORNIA GEOLOGICAL SURVEY

NOTE

55

A tsunami is a wave, or series of waves, generated by an

earthquake, landslide, volcanic eruption, or even large

meteor hitting the ocean (The Japanese word tsu means

“harbor”; nami means “wave”). What typically happens

is a large, submarine earthquake (magnitude 8 or higher)

creates a significant upward movement of the sea floor

resulting in a rise or mounding of water at the ocean

surface. This mound of water moves away from this

center in all directions as a tsunami. A tsunami can travel

across the open ocean at about 500-miles per hour, the

speed of a jet airliner. As the wave approaches land and

as the ocean shallows, the wave slows down to about 30

miles-per-hour and grows significantly in height

(amplitude).

Although most people think a tsunami looks like a tall

breaking wave, like the wave shown in the image of

Japanese artwork (below left), it actually resembles a

flood or surge, like that shown in the picture below right

from the 2004 Indian Ocean Tsunami (images courtesy

of NOAA).

Tsunamis can cause great loss of life and damage to

property, as we learned in the 2004 Indian Ocean

Tsunami which killed over 230,000 people in eleven

different countries. The key to surviving a tsunami is to

know what the warning signs are, and know what to do

and where to go if you think a tsunami is about to strike.

Pictures of evacuation drill in Samoa, California, courtesy Lori

Dengler (Humboldt State University) and Jim Goltz (California

Emergency Management Agency).

©California Department of Conservation, 2012. Reproduction of this CGS Note for classroom or public education purposes is encouraged and does not

require written permission. Please cite California Geological Survey as source. The Department of Conservation makes no warranties as to the

suitability of this product for any particular purpose.

Earthquake! If you feel an

earthquake or become aware that

one has occurred, do not stay in an

area that is susceptible to a

tsunami….move to high ground!

Even a large earthquake thousands

of miles away can trigger a tsunami

that can cross an ocean hours later.

Watch the tides! An approaching tsunami is sometimes

proceeded by a rise or fall of water levels or strange bubbling in the

tidal areas. If this occurs, it could be a sign that a tsunami is on its way.

Head for higher ground!

Stay tuned in! Television, radio, and internet resources are good

places to find out whether a tsunami is heading your way. Emergency

evacuation procedures will be relayed and should be followed as soon

as possible.

When you learn about the warning signs of a tsunami, it might not only

save your life…it might help save the lives of your family and others.

On December 26th, 2004, while vacationing with her family on a beach

in Thailand, Tilly Smith, a 10-year old girl from Great Britain, noticed

that the tide was rushing out and the ocean was strangely bubbling

(similar to the picture shown below; courtesy NOAA). Tilly, who had

studied tsunamis in a geography class two weeks earlier, quickly

realized they were in danger. She warned her mother that it could be a

tsunami and that they had to get off the beach immediately. Her parents

alerted the others at the beach, which was quickly evacuated. The

tsunami hit a few minutes later, but no one on the beach was killed or

seriously injured.

Although the 2004 Indian Ocean Tsunami claimed the lives of over

200,000 people, Tilly Smith likely saved the lives of her family and over

100 other people on that beach. If you remember the warning signs, you

too can become a “tsunami hero.”

The Story of 10-Year-Old Tilly Smith

Distant sources A tsunami caused by a very large earthquake

elsewhere on the Pacific Rim could reach the California coast many (4 to

15) hours after the earthquake. The Alaska-Aleutians Subduction Zone is

an example of a distant source that has caused destructive tsunamis in

California. Notable distant tsunamis that have impacted California

include:

April 1, 1946 – A magnitude 8.8 earthquake in the Aleutian Islands

generated a tsunami that caused damage along the coast of California,

including flooding over 1000-feet inland in Half Moon Bay.

March 28, 1964 – Twelve people were killed in California when a

tsunami was generated by a magnitude 9.2 earthquake off the coast of

Alaska. A surge approximately 20-feet high flooded 29 city blocks of

Crescent City.

March 11, 2011 – A magnitude 9.0 earthquake in the Tohoku region of

Japan produced a moderate amplitude tsunami in California. Although it

did not generate significant flooding in California, strong tsunami

currents caused one death and over $50-million in damages to 27 harbors

statewide, with the most significant damage occurring in Crescent City

and Santa Cruz (pictured below; courtesy Santa Cruz Port District).

Related Websites

www.conservation.ca.gov/cgs

What is your risk? The California Geological Survey (CGS) provides

geologic and seismic expertise to the public, other State government offices, such as the

California Emergency Management Agency (CalEMA), and local government agencies (cities

and counties). With funding from the National Tsunami Hazard Mitigation Program, CGS

worked closely with CalEMA and the Tsunami Research Center at the University of Southern

California to produce statewide tsunami inundation maps for California (an example from the

Santa Barbara area is shown to the right). These maps are used by coastal communities to

produce emergency evacuation plans. You can check to see if you live, work, or vacation in one

of these potential tsunami inundation areas. Visit the CGS tsunami website below to view these

maps, and to learn more about what YOU can do to prepare you and your family for a tsunami.

California Geological Survey tsunami page - www.tsunami.ca.gov California Emergency Management Agency – www.calema.ca.gov and myhazards.calema.ca.gov

Tsunami Research Center at University of Southern California - www.tsunamiresearchcenter.com/

National Tsunami Hazard Mitigation Program - nthmp.tsunami.gov/

Redwood Coast Tsunami Working Group - www.humboldt.edu/rctwg/

National Ocean and Atmospheric Administration Tsunami page - www.tsunami.noaa.gov

THE RESOURCES AGENCY

JOHN LAIRD

SECRETARY FOR NATURAL RESOURCES

STATE OF CALIFORNIA

EDMUND G. BROWN, JR.

GOVERNOR

DEPARTMENT OF CONSERVATION

MARK NECHODOM

DIRECTOR

PAGE 2

Have tsunamis occurred in California? More than eighty tsunamis have been observed or recorded in California

in historic times. Fortunately, almost all of these were small and did

little or no damage. Though damaging tsunamis have occurred

infrequently in California, they are a possibility that must be considered

in coastal communities. There are two sources for California tsunamis,

based on distance and warning time:

Local sources Local tsunami sources, like large offshore faults

and massive submarine landslides, can put adjacent coastal communities

at the greatest risk of a tsunami because the public must respond

quickly with little or no official guidance. The Cascadia Subduction

Zone is an example of a local tsunami source that could threaten

northern California. Stretching from Cape Mendocino, California, to

Vancouver Island, British Columbia, this 700-mile long submarine fault

system forms the crustal plate boundary where the offshore Gorda and

Juan de Fuca plates dive, or subduct, beneath the North American plate.

Examples of local tsunamis that have impacted California include:

January 26, 1700 - An earthquake estimated at a magnitude 9 ruptured

the entire length of the Cascadia Subduction Zone, likely causing a 50-

foot tsunami in parts of northern California. Though there were no local

written accounts, scientists have reconstructed the event based on

geologic evidence and oral histories from the Native American people

in the area, and determined the exact date and time from Japanese

documents that describe the effects of a large tsunami that hit the coast

of Japan later that same day.

December 21, 1812 – A tsunami struck the Santa Barbara and Ventura

coastline shortly after a large earthquake was felt in the area. Though

reports of the size of this tsunami have been debated, the event was

large enough to inundate lowland areas and cause damage to nearby

ships. One theory is that the tsunami was caused by a nearby submarine

landslide triggered by the earthquake.

Notable Historical Tsunamis in the San Francisco Bay Area

- Local Source - Earthquake and tsunami

together

- Distant Source - Tsunamis without felt

earthquakes

Run-up amplitude, in feet, above normal tide

conditions

OBS = observed tsunami activity

NR = No damage or severe conditions reported

Tsunami Source Scenario Model Results for the San Francisco Bay Area

Near shore tsunami heights (flow depths) for both local and distant source scenarios, in FEET above Mean Sea Level. NOTE:

The projections do not include any adjustments for ambient conditions, such as storm surge and tidal fluctuations, and model

error (it is very important to note this difference, as those numbers can increase the projected water height during an event).

Notable Historical Tsunamis in the City of San Francisco

- Local Source - Earthquake and tsunami

together

- Distant Source - Tsunamis without felt

earthquakes

Run-up amplitude, in feet, above normal tide

conditions

OBS = observed tsunami activity

NR = No damage or severe conditions reported

Tsunami Source Scenario Model Results for the City of San Francisco

Near shore tsunami heights (flow depths) for both local and distant source scenarios, in FEET above Mean Sea Level. NOTE:

The projections do not include any adjustments for ambient conditions, such as storm surge and tidal fluctuations, and model

error (it is very important to note this difference, as those numbers can increase the projected water height during an event).

122°22'30"W

122°22'30"W

122°30'0"W

122°30'0"W

37°45'0"N

37°45'0"N

122°22'30"W

122°22'30"W

122°30'0"W

122°30'0"W

37°45'0"N

37°45'0"N

TSUNAMI INUNDATION MAPFOR EMERGENCY PLANNING

0.75 0 0.75 1.50.375Miles

SCALE 1:36,000

1,000 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000500Feet

0.5 0 0.5 1 1.5 20.25Kilometers

Initial tsunami modeling was performed by the University of Southern California (USC) Tsunami Research Center funded through the California Emergency Management Agency (CalEMA) by the National Tsunami Hazard Mitigation Program. The tsunami modeling process utilized the MOST (Method of Splitting Tsunamis) computational program (Version 0), which allows for wave evolution over a variable bathymetry and topography used for the inundation mapping (Titov and Gonzalez, 1997; Titov and Synolakis, 1998). The bathymetric/topographic data that were used in the tsunami models consist of a series of nested grids. Near-shore grids with a 3 arc-second (75- to 90-meters) resolution or higher, were adjusted to “Mean High Water” sea-level conditions, representing a conservative sea level for the intended use of the tsunami modeling and mapping. A suite of tsunami source events was selected for modeling, representing realistic local and distant earthquakes and hypothetical extreme undersea, near-shore landslides (Table 1). Local tsunami sources that were considered include offshore reverse-thrust faults, restraining bends on strike-slip fault zones and large submarine landslides capable of significant seafloor displacement and tsunami generation. Distant tsunami sources that were considered include great subduction zone events that are known to have occurred historically (1960 Chile and 1964 Alaska earthquakes) and others which can occur around the Pacific Ocean “Ring of Fire.”In order to enhance the result from the 75- to 90-meter inundation grid data, a method was developed utilizing higher-resolution digital topographic data (3- to 10-meters resolution) that better defines the location of the maximum inundation line (U.S. Geological Survey, 1993; Intermap, 2003; NOAA, 2004). The location of the enhanced inundation line was determined by using digital imagery and terrain data on a GIS platform with consideration given to historic inundation information (Lander, et al., 1993). This information was verified, where possible, by field work coordinated with local county personnel.The accuracy of the inundation line shown on these maps is subject to limitations in the accuracy and completeness of available terrain and tsunami source information, and the current understanding of tsunami generation and propagation phenomena as expressed in the models. Thus, although an attempt has been made to identify a credible upper bound to inundation at any location along the coastline, it remains possible that actual inundation could be greater in a major tsunami event.This map does not represent inundation from a single scenario event. It was created by combining inundation results for an ensemble of source events affecting a given region (Table 1). For this reason, all of the inundation region in a particular area will not likely be inundated during a single tsunami event.

Tsunami Inundation LineTsunami Inundation Area

MAP EXPLANATIONMETHOD OF PREPARATION

The California Emergency Management Agency (CalEMA), the University of Southern California (USC), and the California Geological Survey (CGS) make no representation or warranties regarding the accuracy of this inundation map nor the data from which the map was derived. Neither the State of California nor USC shall be liable under any circumstances for any direct, indirect, special, incidental or consequential damages with respect to any claim by any user or any third party on account of or arising from the use of this map.

Topographic base maps prepared by U.S. Geological Survey as part of the 7.5-minute Quadrangle Map Series (originally 1:24,000 scale). Tsunami inundation line boundaries may reflect updated digital orthophotographic and topographic data that can differ significantly from contours shown on the base map.

PURPOSE OF THIS MAP

MAP BASE

DISCLAIMER

State of CaliforniaCity and County of San Francisco

California Emergency Management AgencyCalifornia Geological SurveyUniversity of Southern California

Tsunami Inundation Map for Emergency PlanningSan Francisco

State of California ~ City and County of San Francisco

SAN FRANCISCO

June 15, 2009

HUNTERS POINT

SAN FRANCISCO SOUTH

OAKLAND WESTPOINT BONITA

SAN FRANCISCO NORTH

References:Intermap Technologies, Inc., 2003, Intermap product handbook and quick start guide: Intermap NEXTmap document on 5-meter resolution data, 112 p.Lander, J.F., Lockridge, P.A., and Kozuch, M.J., 1993, Tsunamis Affecting the West Coast of the United States 1806-1992: National Geophysical Data Center Key to Geophysical Record Documentation No. 29, NOAA, NESDIS, NGDC, 242 p.National Atmospheric and Oceanic Administration (NOAA), 2004, Interferometric Synthetic Aperture Radar (IfSAR) Digital Elevation Models from GeoSAR platform (EarthData): 3-meter resolution data.Titov, V.V., and Gonzalez, F.I., 1997, Implementation and Testing of the Method of Tsunami Splitting (MOST): NOAA Technical Memorandum ERL PMEL – 112, 11 p.Titov, V.V., and Synolakis, C.E., 1998, Numerical modeling of tidal wave runup: Journal of Waterways, Port, Coastal and Ocean Engineering, ASCE, 124 (4), pp 157-171.U.S. Geological Survey, 1993, Digital Elevation Models: National Mapping Program, Technical Instructions, Data Users Guide 5, 48 p.

This tsunami inundation map was prepared to assist cities and counties in identifying their tsunami hazard. It is intended for local jurisdictional, coastal evacuation planning uses only. This map, and the information presented herein, is not a legal document and does not meet disclosure requirements for real estate transactions nor for any other regulatory purpose.The inundation map has been compiled with best currently available scientific information. The inundation line represents the maximum considered tsunami runup from a number of extreme, yet realistic, tsunami sources. Tsunamis are rare events; due to a lack of known occurrences in the historical record, this map includes no information about the probability of any tsunami affecting any area within a specific period of time.Please refer to the following websites for additional information on the construction and/or intended use of the tsunami inundation map:State of California Emergency Management Agency, Earthquake and Tsunami Program:http://www.oes.ca.gov/WebPage/oeswebsite.nsf/Content/B1EC51BA215931768825741F005E8D80?OpenDocumentUniversity of Southern California – Tsunami Research Center:http://www.usc.edu/dept/tsunamis/2005/index.phpState of California Geological Survey Tsunami Information: http://www.conservation.ca.gov/cgs/geologic_hazards/Tsunami/index.htmNational Oceanic and Atmospheric Agency Center for Tsunami Research (MOST model):http://nctr.pmel.noaa.gov/time/background/models.html

Table 1: Tsunami sources modeled for the City and County of San Francisco coastline.

Area of Inundation Map Coverage and

Sources Used Sources (M = moment magnitude used in modeled event) San Francisco Bay

Point Reyes Thrust Fault X Rodgers Creek-Hayward Faults X Local

Sources San Gregorio Fault X Cascadia Subduction Zone-full rupture (M9.0) X Central Aleutians Subduction Zone #1 (M8.9) X Central Aleutians Subduction Zone #2 (M8.9) X Central Aleutians Subduction Zone #3 (M9.2) X Chile North Subduction Zone (M9.4) X 1960 Chile Earthquake (M9.3) X 1964 Alaska Earthquake (M9.2) X Japan Subduction Zone #2 (M8.8) X Kuril Islands Subduction Zone #2 (M8.8) X Kuril Islands Subduction Zone #3 (M8.8) X Kuril Islands Subduction Zone #4 (M8.8) X

Distant Sources

Marianas Subduction Zone (M8.6) X

MapArea

What

BOATERSshould know

Other resources for tsunami information in California

How should boat owners PREPARE for tsunamis?

Prior to arrival of the March 11, 2011 tsunami along

the California coast, many boat owners took their

boats offshore without adequate supplies or

knowledge of how long they would need to stay

offshore. As a result, boaters tried to re-enter

harbors too early, while dangerous tsunami

conditions still existed. They put themselves and

harbor personnel at risk of injury and death.

Before you plan to leave safe harbor, consider thefollowing:

• Talk to the harbor master or related officials tolearn about your harbor’s tsunami safetyprotocols.

• Sign up to receive tsunami alerts from NOAA andemergency calls from your harbor master orcommunity emergency services office.

• Know weather conditions out on the ocean.

• Know how long it takes your boat to get to deepwater. The 100-fathom line is the NOAArecommendation.

• Have adequate supplies (water, shelter, food)and fuel to remain at sea for 24 hrs or more.

• Have a family plan for tsunamis in place so youknow your family will be safe.

If you do not have these essential preparednessitems covered, DO NOT attempt to take your boatoffshore. Secure your boat to the dock and leavethe dock area before the tsunami arrives.

State of California Tsunami Program

(California Geological Survey website):

www.tsunami.ca.gov/

California Office of Emergency Services Earthquake and Tsunami Program:

www.caloes.ca.gov/PlanningandPreparedness/Pages/Tsunami-Preparedness.aspx

NOAA – National Weather Service

Weather Forecast Offices:

Eureka – www.wrh.noaa.gov/eka/

SF Bay/Monterey – www.wrh.noaa.gov/mtr/

Los Angeles/Oxnard – www.wrh.noaa.gov/lox/

San Diego - www.wrh.noaa.gov/sgx/

Federal Emergency Management Agency:

www.ready.gov/tsunamis

Redwood Coast Tsunami Work Group/ Humboldt State University:

www.humboldt.edu/rctwg/

California Harbor Master and Port Captain Association :

www.harbormaster.org/

Marine Recreation Association:

marina.org

CA Boating Safety Officers Association:

cbsoa.org

The March 11, 2011 tsunami in Santa Cruz Harbor

Crescent City Harbor after the March 11, 2011 tsunami

Prepared by:

Funded by: Boat attempting to leave Crescent City Harbor during the

March 11, 2011 tsunami

What is a TSUNAMI?

Should you take your boat OFFSHORE?

A tsunami is a series of water surges usuallycaused by an earthquake beneath the seafloor. These can cause strong, dangerouscurrents inside harbors and bays.

TSUNAMIS CAN TRICK YOU!

• The first surge may not be the largest.

• It is not unusual for tsunami surges tocontinue for 12 hours and in some casesmuch longer.

• Just when you think it is all over, anothervery large surge may come.

2 Ways to Know if a

Tsunami is Coming:

*Natural Warnings*

On shore: GROUND SHAKING, a LOUD OCEANROAR, or the WATER RECEDING UNUSUALLY FARexposing the sea floor.

On the water: You may still feel the earthquakethrough the hull of your boat. You could see arapid and extreme shift to an outgoing tide.

*Official Warnings*

On shore: You may hear an outdoor siren orannouncements from airplanes. Determine howyou can receive a call from your harbor masteror community emergency services office, or signup for NOAA alert notifications (see back).

On the water: You may receive a TsunamiAdvisory or Warning on your marine VHF radio’sCHANNEL 16 or weather frequency (as long asyour radio has the Alert feature).

Natural Warning Official Warning

The natural warnings described to the leftindicate that a tsunami could arrive withinminutes. Your response depends on where youare:

If you are on land or tied up at the dock: Leaveyour boat and go to high ground on foot as soonas possible. You don’t have time to save yourboat in this situation and could die if you try todo so.

If you are on the water but very near shore: Ifyou can beach or dock your boat and get to highground on foot within ten minutes of a NaturalWarning, then this is your best chance. If that isnot possible, head to deep water as quickly aspossible.

If you are in deep water or very close to deepwater: If you are already in 100 fathoms ofwater (600 feet) then you are safe fromtsunamis. If you are in deep water but not quite100 fathoms, head to deeper water.

The answer to this question depends on:

1) The SIZE of the tsunami.

2) How much TIME you have.

3) The PREPAREDNESS of the boat and itscaptain (see back).

4) The WEATHER at sea could be as dangerousas the tsunami itself.

Your harbor master or port captain may providethe best advice. For most harbors in California,it is safer to keep your boat docked during atsunami because most tsunamis are relativelysmall. On the rare occasion when a largertsunami is expected (Warning level), the boatowner may consider taking their boat offshoreusing the criteria above. Do not go offshoreunless you are very sure that you can get to 100fathoms (600 feet) before the tsunami arrives.

Note for trailer boat owners: Expect congestedboat ramps and remember that you have to getyour boat to the trailer, out of the water, andout of the tsunami zone before the tsunamiarrives

The National Weather Service, provides tsunamiinformation for California boaters:

• ADVISORIES – Peak tsunami wave heightsbetween 1-3 feet are expected, indicatingstrong and dangerous currents can beproduced in harbors.

• WARNINGS – Tsunami wave heights couldexceed 3 feet, indicating very strong,dangerous currents and inundation of dry landis anticipated

There are a number of TSUNAMI HAZARDS that couldaffect boats/boaters:• Sudden water-level fluctuations• Boats that hit bottom as water level drops• Strong and unpredictable currents• Tsunami bores and amplified waves• Eddies/whirlpools• Drag on large keeled boats• Collision with other boats, docks, and debris