TSUNAMI: SAMOA PERSPECTIVE Malaefatu Leavasa Ministry of Natural Resources, Environment and Meteorology (Meteorology Division)

INTRODUCTION Tsunami (tidal wave) is coined differently in Samoan terms: ‘galuafi’- in Samoa meaning a wave of fire, associated with the high speed of movement (300 – 600 miles per hour) compared to the fast spread of a fire. It is an earthquake generated tidal wave Not to be confused with ‘galulolo’ – tidal wave, or storm surge – a tropical cyclone effect

Local Tsunami Procedures Organization that identifies and characterizes tsunamigenic events in the immediate source area: At present, the national capability for identifying or characterizing tsunamigenic events in the immediate local source area is weak. The Samoa Meteorology Division (SMD) utilizes the single GSN seismic station to calculate the magnitude and location of local seismic events (using the DIMAS2003 single station software), and basis their decision on whether to issue a tsunami watch/warning using the information produced. This protocol is relatively unreliable. SMD relies heavily on tsunami information bulletins issued by the Pacific Tsunami Warning Center (PTWC), and basis their decision on whether to undertake national procedures to issue a public watch or warning using that information. This protocol of reliance on PTWC is only effective for teletsunamis, and not for tsunamis generated in local geologic settings.

Threshold for declaring a potential local tsunami emergency:  Earthquake Magnitude (Mw) >= 6.5; Located in the Tonga, Samoa, or Fiji Islands Region.   Organization that acts in the information provided by the agency responsible for characterizing the local tsunami threat: The National Disaster Management Office (NDMO) of SMD alerts the National Disaster Council (NDC), (which is chaired by the Prime Minister and comprises cabinet ministers and members of the foreign diplomatic community), as well as local authorities of the threat for their appropriate response. SMD also issue warnings directly to local media outlets (television and radio station) based on the recommended approval by the NDC.

How is the emergency situation terminated?  Based on the recommendation by SMD, and executed through the decision of the NDC. The NDMO alerts local authorities accordingly based on the decision by the NDC. Similarly, SMD alerts the public through relevant media outlets.

Distance Tsunami Procedures   SMD becomes aware of this information, by means of tsunami information bulletins issued by the Pacific Tsunami Warning Center (PTWC) via Fax, Email, and the EMWIN (Emergency Managers Weather Information Network) system. Local verification systems however, are weak. What actions does this organization take with regard to tsunamigenic events from a distant source? The NDMO is contacted, and similar procedures followed in the event of a local tsunami source threat are adhered to.

Con´t What actions are taken in response to warnings issued by PTWC during intersessional periods? Where local capability permits, local information is checked, and the NDMO is notified for their appropriate response actions. Monitoring using web-based sources is intensified, and the procedures followed during the event of a tsunami generated from a local source are implemented. National Sea Level Network: Samoa currently has one tide-gauge installed under the South Pacific Sea Level and Climate Monitoring Project. The station was installed in 1991, and is located on the northern coast of Upolu island, at the Apia wharf. Data is transmitted to the National Tidal Center, Bureau of Meteorology, Australia, via the GOESS satellite system. The gauge is insufficient however in verifying tsunamis generated on the southern coast of Samoa. Information on tsunami occurrences: No local or regional tsunami occurrences have affected Samoa in the last year.

Summary Tsunami mitigation efforts in Samoa are still at their infancy stages. There exists no national seismic network, although plans to establish this network utilizing foreign aid are underway. A proposal has been submitted to JICA (Japan International Cooperation Agency) for the deployment of a short-term Senior JICA Volunteer with 15 years experience in the field of seismology, to assist local authorities in planning the establishment of a national seismic network, as well as national Tsunami and Seismic Operational Response Plans. Assuming this initiative goes as planned, the next step for Samoa would be to submit proposals to either Japan or other interested donors for the actual implementation of these plans. National efforts are currently underway in the development of a national tsunami operational response plan under the World Bank funded Samoa Infrastructure Asset Management Project, Phase II, but mainly in the context of capacity and awareness building. Efforts at the regional level to establish a South Pacific Tsunami Warning Center are currently underway, of which Samoa is involved in. Overall, Samoa still has long road to walk in the area of developing efficient and effective tsunami early warnings and hazard mitigation systems.

Narrative Seismic Network and Data Center: Samoa currently has one (1) GSN/IMS auxiliary seismic station installed, of which events are viewed using the LISS (Live Internet Seismic Server) system. Data is transferred to the CTBTO in Vienna, and onto ASL in New Mexico, via GCI and GOESS satellite systems. The data is then transferred to IRIS-DMC in Seattle where the data is archived. The DIMAS2003 software is used locally to calculate the magnitude and location of events, as the software was designed to calculate these parameters from a single station. The entire process however is relatively obsolete in the context of a worse case scenario, where the operational response time is within a window of approximately 1 to 2 hours. Plans to establish a national seismic network are underway, and it is hoped that the national capability to operate a seismic network will be developed in the next 2 to 5 years.

Communication System – Transmission of warning messages: At the national level, tsunami warnings are communicated via radio and television networks (media outlets), as well as email and fax systems to relevant local authorities. There exists no direct emergency communication system to rural communities and local authorities, although this is an area that is slowly being addressed. SMD intends to utilize the new communication system to be established in the month of January 2006 by the local telecommunications companies, which would enable the transmission of tsunami warnings to cellular phones via email.

Education and information to the public: Tsunami awareness and education falls under the jurisdiction of the NDMO, and the Annual National Disaster Awareness Day to be held in the month of November 2005 will bear a strong emphasis on tsunami warnings and disaster mitigation. SMd, in collaboration with the Samoa Tourism Authority held a tsunami mitigation workshop in the month of January 2005, aimed at raising local coastal tourism resort operators’ awareness of tsunamis, as well as possible methods of mitigating tsunami disasters.

Tsunami Hazard Assessments: An updated national tsunami hazard assessment has not yet been implemented. This is a planned activity in SMD’s 2005/2006 annual management plan. Regional Cooperation:   Samoa is party to the Pacific Tsunami Working Group (PTWG), which is currently I the process of planning the establishment of a South Pacific Tsunami Warning Center to be established in Fiji. It is envisaged that this endeavour will yield fruitful results in the next 2 to 5 years.

SIGNIFICANT CASE STUDIES Historically, tsunamis of any significance that affected Samoa: 1960 – Chilean earthquake, generated a ‘tsunami’, reports of waves that swept up Fagaloa Bay area, east Upolu Island [Samoa Times ed.1960] August 31, 1981 – A South American region earthquake generated a ‘tsunami’, waves swept inland between 20 - 25 metres at Taga and Manono [ Saifaleupolu et.al , 1981]

More information….TSUNAMI PACIFIC TSUNAMI WARNING CENTER (PTWC) Earthquakes are obtained from internet from NEIC. 1. Earthquakes >6.5 and <7.5mag or < 7.0 in the Aleutian Islands – Information Bulletin is issued by PTWC. 2. Earthquakes > 7.5 (>7.0 in the Aleutian Is) – Tsunami Warning/Watch Bulletins are issued. Regions within 3 hours of tsunami travel time will receive warning . Regions between 3 – 6 hrs of tsunami travel time will receive watch.

More information….TSUNAMI TRAVEL TIMES FOR TSUNAMI WAVE FROM PERU EARTHQUAKE IN JUNE 2001(SEA LEVEL AND CLIMATE MONITORING PROJECT COUNTRY REPORT – MARCH 2003)

More information….TSUNAMI TSUNAMI WAVE DUE TO PERU EARTHQUAKE (SIMULATED AMPLITUDE)

More information…..TSUNAMI APIA SEA LEVEL IN RESPONSE TO PERU EARTHQUAKE (JUNE 2001) PEAK TO TROUGH AMPLITUDE ~30 CM (SLCMP- COUNTRY REPORT - MARCH 2003)

Thank you for your attention Faafetai tele lava