3TSUNAMI WAVESCaused by Earthquakes under Ocean, or other events – landslides, volcanic eruptions, asteroid impacts, etc.In Deep Ocean the Tsunami Wave isonly about 3 feet high but 100 miles wideand moving at speed of a jet airplane.
5Alfred Wegner observed that South America and Africa continents fit like a gig saw puzzle Proposed Continental Drift of Plates (Plate Tectonics) and that 200 millionYears ago a super continent of Pangaea existed.
7SEA FLOOR SPREADINGOccurs along the Mid-Atlantic Ridge pushing the African and European Plates away from the North and South American Plates at about 1 inch/yearThis then pushes the Pacific Ocean floor under the Plates on the opposite side of America Plates and Euroasian and Africa Plates
1730 Minute Period, 350 km Wave Length, 200 m/s or 750 km/hr having traveled 1500 km in 2 hours since earthquake – 1 meter max wave height.TSUNAMI
18Banda Aceh City, Sumarta Digital Globe Satellite Photos BeforeAfter
19Damage map of Banda Aceh showing the impact of tsunamis wave fronts from two directions. The numerals indicate the tsunami elevation in meters near the beach (white) and flow depth inland (black). (Damage map source: UNOSAT, Tsunami data: Borrero et al. 2006, Jaffe et al., 2006, Matsutomi et al., 2006).
69Earthquake Data Processing WC/ATWC EarlyBird Seismic Processing SystemDeveloped for Fast evaluation of Big quakesGraphical interaction to refine automatic resultsRedundant backup operates concurrently (communications and hardware).
70Sea Level Data Display and Analysis Data acquired at WC/ATWC from NOS, PTWC, and other centers’ sites200+ tide gage signals6 DART stationsData displayed with predicted tide and residualsData real-time, triggered, or satellite delayed (hourly).
73Far-Field Prediction Approach Determine likely fault parameters for large quakes in main tsunami generating zones of the PacificModel quakes of different magnitudes for each zone (> 200 total models)Save maximum amplitudes at tide gages, DARTs, and other places of interest (100+ saved/model)
74TYPES OF TSUNAMI MESSAGES INFORMATION BULLETIN: Large earthquake but no tsunami threat (6.5 <= Mw < 7.5)Watch/Warning: Large, Shallow, under water, Earthquake (Mw >= 7.5)WATCH: First wave is 3-6 hours awayWARNING: First wave is < 3 hours awayPacific-Warning: Confirmed destructive waves moving across the Pacific
76Sumatra Earthquake PTWC TIMELINE (GMT) 00:59 Sumatra EQ Starts 01:07 Watchstanders pagedby digital alarm01:09 PTWC has location01:09 Sumatra EQ Stops01:14 PTWC issues TIBwith Mw=8.002:04 TIB issued withRevised magnitude 8.5No Tide Gauges in Region05:00 Wire reports of deathsIn Thailand and Sri Lanka
77Travel Time Back Track Wave Tracing Back to Source SLIP and RAKE Model PBPSTravel Time Back TrackWave Tracing Back to SourceSLIPandRAKEModelRegional and Tele-SurfaceWaves.Mw = 9.1Where was theMissing MomentReleased?
784hr After having learned that there was a destructive tsunami, PTWC set aboutreaching Nations ahead ofthe wave.
79March 28, 2005Mw=8.2 UpgradedTo 8.5 then to 8.7!!No reports of TsunamiDamage.One Degree South ofWhere Dec 26 eventStarted.Aftershock?Faulting continuingSouthwards?
80ConclusionsThe Tsunami caused by the Sumatra EQ killed >300,000 people because there was no Warning System.Source region for Sumatra Tsunami extends from Banda Aceh through the Nicobar Islands.We need a method for estimating size of great earthquakes within a time frame useful to the Tsunami Warning System.
81Tsunami WarningsIf you are at the beach and feel an earthquake – GO TO HIGH GROUND (>100 feet above MSL)If the water level drops below low tide level – GO TO HIGH GROUNDIf you hear a siren near the beach – GO TO HIGH GROUNDIf in or near multi-storied concrete building – GO UP IN BUILDING ABOVE THIRD FLOOR