Tsunami Research Center

Aggeliki Barberopoulou gives an interview on the origins of the 2011 Japan tsunami.

http://www.livescience.com/13180-japan-tsunami-earthquake-explained.html

ITIC Tsunami Bulletin Board
Web message at http://wcatwc.arh.noaa.gov/2011/03/11/lhvpd9/04/messagelhvpd9-04.htm

WEPA41 PAAQ 110851
TSUWCA

BULLETIN
TSUNAMI MESSAGE NUMBER 4
NWS WEST COAST/ALASKA TSUNAMI WARNING CENTER PALMER AK
1251 AM PST FRI MAR 11 2011

THE WARNING AND ADVISORY STATUS REGIONS HAVE CHANGED IN THIS
MESSAGE.

…THE TSUNAMI WARNING CONTINUES IN EFFECT FOR THE COASTAL
AREAS OF CALIFORNIA AND OREGON FROM POINT CONCEPCION
CALIFORNIA TO THE OREGON-WASHINGTON BORDER…

…THE TSUNAMI WARNING CONTINUES IN EFFECT FOR THE COASTAL
AREAS OF ALASKA FROM AMCHITKA PASS ALASKA/125 MILES W OF
ADAK/ TO ATTU ALASKA…

…THE TSUNAMI ADVISORY CONTINUES IN EFFECT FOR THE COASTAL
AREAS OF CALIFORNIA FROM THE CALIFORNIA-MEXICO BORDER TO
POINT CONCEPCION CALIFORNIA…

…THE TSUNAMI ADVISORY CONTINUES IN EFFECT FOR THE COASTAL
AREAS OF WASHINGTON – BRITISH COLUMBIA AND ALASKA FROM THE
OREGON-WASHINGTON BORDER TO AMCHITKA PASS ALASKA/125 MILES
W OF ADAK/…

RECOMMENDED ACTIONS
A TSUNAMI HAS BEEN GENERATED WHICH IS EXPECTED TO CAUSE DAMAGE
TO THE WARNING AND/OR ADVISORY REGIONS LISTED IN THE HEADLINE.
PERSONS IN LOW-LYING COASTAL AREAS SHOULD BE ALERT TO
INSTRUCTIONS FROM THEIR LOCAL EMERGENCY OFFICIALS. EVACUATIONS
ARE ONLY ORDERED BY EMERGENCY RESPONSE AGENCIES.
– PERSONS IN TSUNAMI WARNING COASTAL AREAS SHOULD MOVE INLAND TO
HIGHER GROUND.

– PERSONS IN TSUNAMI ADVISORY COASTAL AREAS SHOULD MOVE OUT OF
THE WATER… OFF THE BEACH AND OUT OF HARBORS AND MARINAS.

MEASUREMENTS OR REPORTS OF TSUNAMI ACTIVITY

LOCATION LAT LON TIME AMPL
———————— —– —— ——- ———–
TOSASHIMIZU JAPAN 32.8N 132.9E 0747UTC 00.9FT/00.27M
TOKAI JAPAN 33.8N 137.6E 0645UTC 00.8FT/00.25M
OFUNATO JAPAN 39.0N 141.8E 0605UTC 10.8FT/03.29M
HANASAKI JAPAN 43.3N 145.6E 0643UTC 09.3FT/02.82M
BOSO JAPAN 34.8N 140.8E 0609UTC 02.6FT/00.78M

TIME – TIME OF MEASUREMENT
AMPL – TSUNAMI AMPLITUDES ARE MEASURED RELATIVE TO NORMAL SEA LEVEL.
IT IS …NOT… CREST-TO-TROUGH WAVE HEIGHT.
VALUES ARE GIVEN IN BOTH METERS(M) AND FEET(FT).

DEEP OCEAN SENSORS INDICATE A LARGE TSUNAMI HAS BEEN GENERATED.

PRELIMINARY EARTHQUAKE PARAMETERS
MAGNITUDE – 8.9
TIME – 2046 AKST MAR 10 2011
2146 PST MAR 10 2011
0546 UTC MAR 11 2011
LOCATION – 38.3 NORTH 142.4 EAST
– NEAR EAST COAST OF HONSHU JAPAN
DEPTH – 12 MILES/20 KM

TSUNAMI WARNINGS MEAN THAT A TSUNAMI WITH SIGNIFICANT WIDESPREAD
INUNDATION IS IMMINENT OR EXPECTED. WARNINGS INDICATE THAT
WIDESPREAD DANGEROUS COASTAL FLOODING ACCOMPANIED BY POWERFUL
CURRENTS IS POSSIBLE AND MAY CONTINUE FOR SEVERAL HOURS AFTER THE
INITIAL WAVE ARRIVAL.

TSUNAMI ADVISORIES MEAN THAT A TSUNAMI CAPABLE OF PRODUCING
STRONG CURRENTS OR WAVES DANGEROUS TO PERSONS IN OR VERY NEAR THE
WATER IS EXPECTED. SIGNIFICANT WIDESPREAD INUNDATION
IS NOT EXPECTED FOR AREAS UNDER AN ADVISORY. CURRENTS MAY BE
HAZARDOUS TO SWIMMERS… BOATS… AND COASTAL STRUCTURES AND MAY
CONTINUE FOR SEVERAL HOURS AFTER THE INITIAL WAVE ARRIVAL.

PACIFIC COASTAL REGIONS OUTSIDE CALIFORNIA/ OREGON/ WASHINGTON/
BRITISH COLUMBIA AND ALASKA SHOULD REFER TO THE PACIFIC TSUNAMI
WARNING CENTER MESSAGES FOR INFORMATION ON THIS EVENT AT
WWW.WEATHER.GOV/PTWC.

THIS MESSAGE WILL BE UPDATED IN 60 MINUTES OR SOONER IF
THE SITUATION WARRANTS. THE TSUNAMI MESSAGE WILL REMAIN IN EFFECT
UNTIL FURTHER NOTICE. REFER TO THE INTERNET SITE
WCATWC.ARH.NOAA.GOV FOR MORE INFORMATION.

PZZ530-CAZ034-035-529-530-006-505>509-002-001-ORZ021-022-002-
001-111021-
/O.CON.PAAQ.TS.W.0006.000000T0000Z-000000T0000Z/
COASTAL AREAS BETWEEN AND INCLUDING POINT CONCEPCION
CALIFORNIA TO THE OREGON-WASHINGTON BORDER
1251 AM PST FRI MAR 11 2011

…THE TSUNAMI WARNING CONTINUES IN EFFECT FOR THE COASTAL
AREAS OF CALIFORNIA AND OREGON FROM POINT CONCEPCION
CALIFORNIA TO THE OREGON-WASHINGTON BORDER…

PERSONS IN TSUNAMI WARNING COASTAL AREAS SHOULD MOVE INLAND TO
HIGHER GROUND.

TSUNAMI WARNINGS MEAN THAT A TSUNAMI WITH SIGNIFICANT WIDESPREAD
INUNDATION IS IMMINENT OR EXPECTED. TSUNAMIS ARE A SERIES OF
WAVES POTENTIALLY DANGEROUS SEVERAL HOURS AFTER INITIAL ARRIVAL
TIME. ESTIMATED TIMES OF INITIAL WAVE ARRIVAL FOR SELECTED
SITES IN THE WARNING ARE PROVIDED BELOW.

CHARLESTON-OR 0715 PST MAR 11 SEASIDE-OR 0724 PST MAR 11
CRESCENT CITY-CA 0723 PST MAR 11 SAN FRANCISCO-CA 0808 PST MAR 11

FOR ARRIVAL TIMES AT ADDITIONAL LOCATIONS SEE
WCATWC.ARH.NOAA.GOV

We assess tsunami hazards in San Diego Bay, California, using newly identified
offshore tsunami sources and recently available high resolution bathymetric/topographic
data. We simulate locally, regionally and distant-generated tsunamis.
Local tsunami source models use more realistic fault and landslide data than previous
efforts. With the exception of the Alaska-Aleutian Trench, modeling results suggest
that local sources are responsible for the largest waves within the San Diego Bay and
Mission Bay. Because San Diego Bay is relatively well protected by North Island and the
Silver Strand, the wave heights predicted are consistently smaller inside the harbor than
outside. However, historical accounts, recent tsunamis and our predictions show that San
Diego Bay is vulnerable to strong tsunami induced currents. More specifically, large
currents are expected inside the harbor for various distant and local tsunami sources with
estimated flow velocities exceeding 100 cm/s. Such currents have been damaging to harbor
facilities, such as wharves and piers, and may cause boats to break from moorings and ram
into adjacent harbor structures, as observed in recent historic tsunamis. More recently,
following the Mw 8.8 February 27, 2010 Chile earthquake, tsunami-currents damaged
docks/piers in Shelter Island confirming our findings.

Prepared for the National Science Foundation by Costas Synolakis. Appearances by Professors Hermann Fritz, Jose Borrero, Costas Synolakis, and Mr. Vassilios Skanavis.

On October 25, 2010 a magnitude 7.7 earthquake struck south of S. Pagai island off Sumatra, triggering a tsunami that killed over 400 people. Initial reports related that there was no warning communicated to the Mentawais and that the Indonesian tsunami warning system had broken down. Be that as it may have been, the death toll is perplexing in view of the 2007 earthquake and tsunami in the same region that killed nobody because people self-evacuated. If they did it then, why didn’t they do it now ? This was a question that an NSF expedition as part of the International Tsunami Survey Team strove to investigate in the field survey from November 8 to November 19.

The initial assessment of the TRC can be found at the Wall Street editorial – Waving the tsunami warning flag. After the field survey, the findings largely confirmed the early inferences. The reason that this event was so much more deadly than the 2007 event was that the earthquake was weakly felt, if at all, in most of the Pagais. Locals had been told to self evacuate only if the shaking was stronger than the 2007 event, and hence some didn’t even bother to get out of their beds. The earthquake struck at night, few if any saw the first wave of the tsunami – eyewitnesses who fled reported hearing the sound of the advancing tsunami.

There was no warning disseminated in the Mentawais. Residents in Padang reported that they saw an announcement on television, but didn’t evacuate because it only warned of the potential of a tsunami. Most residents in Sikasap reported not seeing the announcement, and a few were alerted by relatives who telephoned them from elsewhere in Sumatra. In most coastal villages in the Pagais or Sipura there is no electricity or telephone communications, so residents couldn’t had received the televised alert.
The warning system failed, even if it is eventually determined that the TV alert was broadcast before the tsunami arrival in the Mentawais.  Currently, the Indonesian tsunami warning system only detects earthquakes, and there should had been provisions for alerting even the most remote coastal villages of the Mentawais, a particularly high risk area for tsunamis. While public education for self evacuation is priority one, there are unusual events which do no allow for direct observation of the common harbinger clues of a tsunami, such as strong ground shaking that lasts over 30 seconds or unusual shoreline motions. A “slow” earthquake (a tremor that produces less felt shaking in comparison with its size) which strikes at night is a nightmare scenario, which unfortunately materialized on 25 October. Even fairly well tsunami-educated residents in self-evacuation failed to take action, exactly because they harbinger signs of the impeding catastrophe were not felt or observed in a manner that would trigger a flee or die response.
The death toll was unnecessarily high. Solar powered sirens connected via VHF or wireless technology to Sikasap are necessary to save lives. Public education efforts must continue to reinforce the knowledge that any ground shaking that lasts over 30sec should trigger self-evacuation. Indonesia needs to install a whole array of tsunami detectors like NOAA’s DARTs to allow for rapid verification of tsunami generation to improve the accuracy of the warnings, but also to allow for informed all clear messaging, an important part of any warning system. As it happened, some local residents stayed away for days not knowing if it was safe to return, others returned too quickly only to flee when they heard the noise from subsequent waves advancing to their villages.

More information can be found in the two post survey articles in the Jakarta Globe.

Lives Could Have Been Saved in Mentawai
Mentawai Tsunami was 17 Meters High

Re-posted from the Wall Street Journal Asia:

This week’s twin disasters in Indonesia—the eruption of Mount Merapi and the 7.7-magnitude earthquake off west-central Sumatra—have again brought warning systems and emergency preparedness into the spotlight. The resulting view is far from flattering.

The tsunami struck at 9:42 p.m. local time on Oct. 25, only a few hours before the volcano erupted. The tsunami death toll is likely to climb beyond the 350 at which it currently stands, while the volcano killed 30.

Both nature and man worked against the victims. The undersea tremor that caused Monday’s deadly wave was a rare “tsunami earthquake,” a tremor that for some reason produces a tsunami far larger than is normal for an earthquake of that magnitude. Because of this, most people on shore did not feel the earthquake, so the first sign the wave was coming was the roar of it crashing ashore.

Yet those hundreds of deaths were far from inevitable. That the victims had no warning marks a failure of the German-Indonesian Tsunami Warning System (GITWS), inaugurated with great fanfare two years ago. The system, developed at a cost of $69 million, was supposed to avert another catastrophe like the 2004 Boxing Day tsunami that claimed 184,000 lives, 131,000 of those in Indonesia. It features a futuristic control room in Jakarta and a system of tsunamographs—devices to record sea levels in deep water, which relay data back to the control room via buoys on the ocean surface.

Those recorders were plagued by problems from the start. Sometimes deep ocean moorings would break off and the buoys would float off. Sometimes signals wouldn’t trigger or relay properly. Fishermen have been known to remove solar panels and use the buoys as anchors. Sharks occasionally bite off pieces of the mooring line.

Solutions exist. For more than a decade the U.S. National Atmospheric and Oceanic Administration has deployed a system that avoids these pitfalls, and their tsunamographs are better than 70% reliable. But Indonesia relied on untested technology and didn’t build in the redundancy—multiple sensors in high-risk areas—common to other systems.

Even if the GITWS system had worked, it’s still not clear the message would have gotten out to those who needed it. UNESCO’s Pacific Tsunami Warning Center in Hawaii issued a warning about eight minutes after the earthquake, but that message didn’t reach the public in time. Rapid warning dissemination remains key for effective civil protection.

It’s inexcusable that these problems persist today. On average, one earthquake capable of producing a tsunami shakes Sumatra every year. Southeast Asia is one of the most studied regions in the world in terms of tsunamis and seismic phenomena. So what has gone wrong?

To answer that, it is first important to understand what has gone right. Thanks to better public education, more people now know the most common warning signs for a tsunami and how to self-evacuate without an official order. Several research groups have developed evacuation maps for the region that would have helped people reach safety ahead of a tsunami a little bigger than the one that materialized in this case.

Yet further progress is constrained by the fact that emergency managers in Indonesia, as elsewhere, always plan for the last disaster instead of the next one. Bureaucrats by nature prefer specific checklists and the like. As a result, planning tends to be much more “event-specific”—developing detailed action plans for evacuating x number of people from y area ahead of a wave of z size. That scenario inevitably resembles the most recent disaster that planners encountered.

It would be better to focus on first principles: bolstering the ability to detect potential tsunamis and warn people as early as possible. For cases like this where people on the shore see no warning signs, the key is to focus on how authorities will know there’s a danger and get that message out. In this framework, the problems dogging GITWS transmitters should have been the top concern of disaster planners, not one of many issues on a long to-do list.

It has now been six years since the disaster that made “tsunami” a household word. Another four tsunamis in Indonesia have claimed more than 1,000 lives. Asia needs the best technology and the best minds working together. No country can be prepared for all natural disasters that might strike. But we can do far better, if we choose to learn from the experience of others.

Mr. Synolakis is director of the Tsunami Research Center at the Viterbi School of Engineering of the University of Southern California.