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Establishment and Operation of a Establishment and Operation of a Regional Tsunami Warning CentreRegional Tsunami Warning Centre

Dr. Charles McCreery, DirectorDr. Charles McCreery, DirectorNOAA Richard H. Hagemeyer Pacific Tsunami Warning CenterNOAA Richard H. Hagemeyer Pacific Tsunami Warning Center

Ewa Beach, Hawaii USAEwa Beach, Hawaii USA

Why A Regional Tsunami Warning Centre?Why Not Just a Global Centre?

With modern communications it should be possible to access the regional seismic and sea level data in real time from a single Global Centre, and to quickly disseminate warning information from such a Centre out to local authorities and the public. However, a Regional Centre provides:

• Regional Interaction: Better communication of issues between regional stakeholders who are more familiar with each other and have common regional challenges.

• Regional Ownership and Control: Responsibility and control stays in the region that is at risk.

• Regional Focal Point for Mitigation: As office with long-term support and persons 100% devoted to tsunami issues, Regional Centre can provide regional expertise and be a focal point for other regional mitigation activities.

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Why A Regional Tsunami Warning Centre?Why Not Just National Centres?

• Warning Capabilities: National seismic and sea level data may effectively address a local tsunami threat, but not a regional one. Data from outside a country’s borders is needed to protect that country’s coast.

• Shared Services: Regional Centre can provide warning guidance to countries with limited national capabilities.

• Regional Efficiencies: Required data collection systems, communications infrastructure, real time analysis capabilities, and 24x7 operations take resources.

National Centres are Critical• Address Local Tsunami Threat: Local tsunamis are most

effectively addressed by national systems using national seismicand sea level monitoring capabilities and local warning dissemination methods

• Independent Alert for Regional Event: Detection of a potential regional threat can be accomplished with even a single seismic station (e.g., with TREMORS)

• Interpretation of Warnings from the Regional Center: It is the national responsibility to interpret regional warnings and make decisions regarding how to respond.

• Warning Dissemination: National centers work with civil authorities to ensure warnings are disseminated quickly to areasat risk and to establish evacuation routes and plans.

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Regional Tsunami Warning DesignASSESS THE THREAT

• What are the likely tsunami generation mechanisms for the region (earthquakes, landslides, volcanoes)?

• Where are their likely source zones?

• What are the characteristics of likely tsunamis (frequency of occurence, maximum size, attenuation with distance)?

ASSESS THE RISK

• What coasts are threatened by tsunamis?

• Who and what is at risk on those coasts?

HOW TO WARN

• How quickly detect, confirm, forecast the tsunami?

• How much time do you have between sources and coasts?

• What infrastructure exists for dissemination?

Regional Tsunami Warning StrategyBASED ON LEVEL OF RISK, AMOUNT OF LEAD TIME AVAILABLE,

INFRASTRUCTURE FOR WARNING DELIVERY

• What coastal areas need a warning (for local tsunamis, may decide on education only)?

• What kind of warning forecast is needed, and what data and forecast techniques are needed?

• What is an acceptable level for false warnings?

• What seismic data is available, needed?

• What coastal sea level data is available, needed?

• What deep ocean sea level data is available, needed?

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Regional Tsunami Warning Centre ProductsINFORMATION BULLETINS

• For events with no or very little tsunamigenic potential

• Assure that no or minimal threat exists

• Exercise the system (since warnings are rare)

WARNING, WATCH, AND ADVISORY BULLETINS

• For events with destructive tsunami potential (estimated or confirmed)

• Contains information on source (EQ parameters)

• Contains tsunami observations

• Contains estimated arrival times and impacts

• Contains general evaluation and safety information

• Tells when next bulletin can be expected

Other Tsunami Warning Centre ProductsCOMMUNICATIONS TESTS

• Bulletins issued on a recurring basis (monthly) that require a response from recipients to ensure communications and other readiness

HISTORICAL DATA MAP (web)

• Shows historical earthquakes in region of epicenter

• Shows historical tsunamigenic events

TSUNAMI TRAVEL TIME MAP (web)

• Shows estimated tsunami travel time contours

TSUNAMI HEIGHT MAP (web)

• Shows directionality of tsunami energy based on model estimates of maximum wave heights in ocean

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Tsunami Warning Reliability Strategy(for 24x7, no single points of failure)

• REDUNDANT DATA SOURCES

• REDUNDANT COMMUNICATIONS PATHS FOR DATA

• REDUNDANT COMMUNICATIONS PATHS FOR MESSAGES

• REDUNDANT COMPUTERS AND OTHER I.T. COMPONENTS

• UNINTERUPTIBLE POWER SUPPLY WITH GENERATOR BACKUP

• REDUNDANT EVENT ALARMS

• AT LEAST TWO ANALYSTS ON DUTY 24x7

• REDUNDANT INDEPENDENT ANALYSES METHODS

• BACKUP WARNING CENTRE(S)

Regional Tsunami Warning Centre:Interaction with Other Centres

• REAL TIME DATA EXCHANGE (MULTIPLE SOURCES, COMMUNICATION PATHS)

• REAL TIME PARAMETER EXCHANGE (INDEPENDENT ANALYSES)

• EXPERTISE EXCHANGE (DEVELOPMENT OF NEW TECHNIQUES & STRATEGIES)

• QUALITY CONTROL (CRITICAL ANALYSIS OF RESULTS)

• PERSONNEL EXCHANGE (CROSS-POLLINATION)

• BACKUP FUNCTION (OFFICIAL DESIGNATION, PROCEDURES)

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Regional Tsunami Warning Centre:Long Term Sustainability

REGIONAL COMMITMENT AND SUPPORT

• Regional Interest, Coordination, and Cooperation facilitated by UNESCO/IOC

• Region provides support in its own interest

NATIONAL SUPPORT

• Hosting country committed to long term support in its own interest as well as regional interest

MULTI-HAZARD

• Hosting Agency (e.g., a Met Service) has multi-hazard responsibilities with overlapping capabilities, resources

INTERNATIONAL SUPPORT

• Data standards, sharing, facilitated by GEOSS

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HOW DOES THE PACIFIC TSUNAMI HOW DOES THE PACIFIC TSUNAMI WARNING CENTER FUNCTION?WARNING CENTER FUNCTION?

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KEY OPERATIONALKEY OPERATIONAL ACTIVITIESACTIVITIES

•• SEISMIC DATA COLLECTION & ANALYSESSEISMIC DATA COLLECTION & ANALYSES

•• SEA LEVEL MEASUREMENTSSEA LEVEL MEASUREMENTS

•• DECISIONDECISION--MAKING PROCESSESMAKING PROCESSES

•• MESSAGE CREATION & DISSEMINATIONMESSAGE CREATION & DISSEMINATION

OPERATIONAL OPERATIONAL GOALSGOALS

•• FASTERFASTER

•• MORE ACCURATEMORE ACCURATE

•• MORE RELIABLEMORE RELIABLE

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Tsunami Travel Time Isochrons 1-Hour Contours

P-WAVE TRAVEL TIMES FOR 12/26/04 EARTHQUAKE

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MIDW

RPN

WAKE

PITC

AUTOMATICSOLUTIONS

FORPACIFICEVENTS

INITIAL LOCATION IN 3 - 8 MIN

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INTERACTIVE TOOL TO REFINE SOLUTION INCLUDING DEPTH

INTERACTIVE TOOL TO

DETERMINEMWP

MOMENTMAGNITUDE

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Performance of PTWC Mwp

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

5 6 7 8 9 10Harvard Mw

Mw

p (P

TWC

) - M

w (H

RV)

ISSUE TIME OF PTWC INITIAL BULLETINS FOR TELESEISMS

0

10

20

30

40

50

60

70

80

90

100

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

EVENT TIME (YEAR)

MIN

UTE

S SI

NC

E Q

UA

KE

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HAWAII LOCAL TSUNAMI THREATREPEAT OF 1868 OR 1975

KONA

HILO

~15 MINUTES~15 MINUTESTRAVEL TIMETRAVEL TIME

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AUTOMATICSOLUTIONS

FORHAWAIIEVENTS

INITIAL LOCATION IN 20 SEC

ISSUE TIME OF PTWC BULLETINS FOR HAWAII EVENTS

0

5

10

15

20

25

30

1994 1996 1998 2000 2002 2004 2006

EVENT TIME (YEAR)

ELA

PSED

MIN

UTE

S

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KEY SEISMIC CHALLENGESKEY SEISMIC CHALLENGES::

1.1. REDUCE FALSE WARNINGS BASED ON REDUCE FALSE WARNINGS BASED ON SEISMIC DATASEISMIC DATA

2.2. KNOW A 9.3 IS A 9.3 AND WHERE THE KNOW A 9.3 IS A 9.3 AND WHERE THE RUPTURE TOOK PLACE WITHIN, SAY, RUPTURE TOOK PLACE WITHIN, SAY, ONE HOUR.ONE HOUR.

Shallow Pacific Earthquakes

0

100

200

300

400

500

7.3 7.4 7.5 7.6 7.7 7.8 7.9 8 8.1 8.2 8.3 8.4 8.5

Mw

Num

ber o

f Eve

nts

per C

entu

ry

Values projected from Harvard CMT Catalog

2500 Events

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DestructiveLocal

Tsunamis

Cum

ulat

ive

Even

ts p

er C

entu

ry ≥

Mw

Val

ue

Moment Magnitude, Mw

Information Bulletin

Mw = 6.5-7.5

Fixed 1000kmRegional Warning

Mw = 7.6-7.8

Expanding 3+3 hourRegional Warning/Watch

Mw > 7.8

150 Events----------------

20Destructive

Local or Regional Tsunamis

100 Events----------------

30Destructive

Local or Regional Tsunamis

8Tele-

Tsunamis

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Sumatra EarthquakeMw = 9.3

Rupture Length ~ 1200km

Source Duration ~ 500s

Rupture propagated SouthTo North

=> Generated Basin wide Destructive tsunami thatkilled > 290,000 people

Slip Distribution of 12/26/05 Earthquake (USGS)

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FK Azimuth variation with time Indicates Rupture Extent

• North-to-south rupture, inferred from aftershock location relative to the main-shock.

• Azimuth of the T-phase varies from south to north, consistent with the probable rupture.

• By 01:40, the size of the fault rupture (> 1000 km) could be known using the T-Phase Azimuth.

The white line is the azimuth propagating out from Diego Garcia. The red star is the main-shock hypocenter, and the grey dots are aftershock locations. The plot on the right is the energy envelope over time from the FK analysis. The red line is the current time step.

TSUNAMI WAVE MEASUREMENT ANDTSUNAMI WAVE MEASUREMENT ANDFORECASTING CHALLENGESFORECASTING CHALLENGES::

1.1. MORE QUICKLY DETECT AND MEASURE MORE QUICKLY DETECT AND MEASURE TSUNAMI WAVES TO CANCEL OR TSUNAMI WAVES TO CANCEL OR UPGRADE WARNINGUPGRADE WARNING

2.2. PROVIDE MORE ACCURATE AND AREAPROVIDE MORE ACCURATE AND AREA--SPECIFIC FORECASTSSPECIFIC FORECASTS

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SEA LEVEL GAUGES USED BY PTWC

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DEEP OCEAN, REAL TIMETSUNAMI REPORTING SYSTEMThe tsunami

signal is detected by a pressure sensor on the ocean floor. That signal is relayed by acoustic telemetry to thebouy. The buoy in turn transmits the signal via satellite back to the warning centers.

SEA LEVEL GAUGES USED BY PTWC

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17 November 2003: 17 November 2003: SIFT MatchSIFT Match of Waveformsof Waveforms of of GenerationGeneration--Propagation Model and TsunameterPropagation Model and Tsunameter

Real Time Detection of Real Time Detection of November 17, 2003 TsunamiNovember 17, 2003 Tsunami

Tsunami

TsunamiTsunami

Seismic

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A POSSIBLE DART BUOY CONFIGURATION (32 DARTS)

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CONCLUSIONSCONCLUSIONS•• Regional Tsunami Warning Centres are Regional Tsunami Warning Centres are

needed to protect other ocean basins needed to protect other ocean basins from the tsunami hazard, even if rare. from the tsunami hazard, even if rare.

•• Development of new Regional Tsunami Development of new Regional Tsunami Warning Centres can take advantage of Warning Centres can take advantage of experiences gained in the Pacific.experiences gained in the Pacific.

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THANK YOUTHANK YOU