Establishment and Operation of a Regional Tsunami Warning Centre Dr. Charles McCreery, Director NOAA Richard H. Hagemeyer Pacific Tsunami Warning Center Ewa 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. 1
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 seismic and 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 areas at risk and to establish evacuation routes and plans. 2
Regional Tsunami Warning Design ASSESS 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 Strategy BASED 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? 3
Regional Tsunami Warning Centre Products INFORMATION 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 Products COMMUNICATIONS 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 4
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) 5
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 I HOW DOES THE PACIFIC TSUNAMI WARNING CENTER FUNCTION? 6
KEY OPERATIONAL ACTIVITIES SEISMIC DATA COLLECTION & ANALYSES SEA LEVEL MEASUREMENTS DECISION-MAKING PROCESSES MESSAGE CREATION & DISSEMINATION OPERATIONAL GOALS FASTER MORE ACCURATE MORE RELIABLE 7
Tsunami Travel Time Isochrons 1-Hour Contours P-WAVE TRAVEL TIMES FOR 12/26/04 EARTHQUAKE 8
MIDW WAKE PITC RPN AUTOMATIC SOLUTIONS FOR PACIFIC EVENTS INITIAL LOCATION IN 3-8 MIN 9
INTERACTIVE TOOL TO REFINE SOLUTION INCLUDING DEPTH INTERACTIVE TOOL TO DETERMINE MWP MOMENT MAGNITUDE 10
0.4 Performance of PTWC Mwp 0.2 Mwp (PTWC) - Mw (HRV) 0-0.2-0.4-0.6-0.8-1 -1.2 5 6 7 8 9 10 Harvard Mw 100 ISSUE TIME OF PTWC INITIAL BULLETINS FOR TELESEISMS 90 MINUTES SINCE QUAKE 80 70 60 50 40 30 20 10 0 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 EVENT TIME (YEAR) 11
HAWAII LOCAL TSUNAMI THREAT REPEAT OF 1868 OR 1975 ~15 MINUTES TRAVEL TIME HILO KONA 12
AUTOMATIC SOLUTIONS FOR HAWAII EVENTS INITIAL LOCATION IN 20 SEC ISSUE TIME OF PTWC BULLETINS FOR HAWAII EVENTS 30 25 ELAPSED MINUTES 20 15 10 5 0 1994 1996 1998 2000 2002 2004 2006 EVENT TIME (YEAR) 13
KEY SEISMIC CHALLENGES: 1. REDUCE FALSE WARNINGS BASED ON SEISMIC DATA 2. KNOW A 9.3 IS A 9.3 AND WHERE THE RUPTURE TOOK PLACE WITHIN, SAY, ONE HOUR. Cumulative Number Events of Events per Century per Century Mw Value 500 400 300 200 100 0 Information Bulletin Mw = 6.5-7.5 2500 Events ---------------- 23 Destructive Local Tsunamis Shallow Pacific Earthquakes Fixed 1000km Regional Warning Mw = 7.6-7.8 150 Events ---------------- 20 Destructive Local or Regional Tsunamis 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 Moment Magnitude, Mw Mw Expanding 3+3 hour Regional Warning/Watch Mw > 7.8 100 Events ---------------- 30 Destructive Local or Regional Tsunamis 8 Tele- Tsunamis Values projected from Harvard CMT Catalog 14
Sumatra Earthquake M w = 9.3 Rupture Length ~ 1200km Source Duration ~ 500s Rupture propagated South To North => Generated Basin wide Destructive tsunami that killed > 290,000 people Slip Distribution of 12/26/05 Earthquake (USGS) 15
FK Azimuth variation with time Indicates Rupture Extent North-to-south rupture, inferred from aftershock location relative to the mainshock. 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 AND FORECASTING CHALLENGES: 1. MORE QUICKLY DETECT AND MEASURE TSUNAMI WAVES TO CANCEL OR UPGRADE WARNING 2. PROVIDE MORE ACCURATE AND AREA- SPECIFIC FORECASTS 16
SEA LEVEL GAUGES USED BY PTWC 17
18
The tsunami signal is detected by a pressure sensor on the ocean floor. That signal is relayed by acoustic telemetry to the bouy. The buoy in turn transmits the signal via satellite back to the warning centers. DEEP OCEAN, REAL TIME TSUNAMI REPORTING SYSTEM SEA LEVEL GAUGES USED BY PTWC 19
17 November 2003: SIFT Match of Waveforms of Generation-Propagation Model and Tsunameter Real Time Detection of November 17, 2003 Tsunami Seismic Tsunami Tsunami Tsunami 20
A POSSIBLE DART BUOY CONFIGURATION (32 DARTS) 21
CONCLUSIONS Regional Tsunami Warning Centres are needed to protect other ocean basins from the tsunami hazard, even if rare. Development of new Regional Tsunami Warning Centres can take advantage of experiences gained in the Pacific. 22
THANK YOU 23