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

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TSUNAMI SAMOA PERSPECTIVEMalaefatu
LeavasaMinistry of Natural Resources,
Environment and Meteorology (Meteorology
Division)
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(No Transcript)
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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

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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.

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• Threshold for declaring a potential local tsunami
  emergency 
• Earthquake Magnitude (Mw) gt 6.5 Located in the
  Tonga, Samoa, or Fiji Islands Region.
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• Organization that acts in the information
  provided by the agency responsible for
  characterizing the local tsunami threat
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• 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.

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• 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.

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Distance Tsunami Procedures

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• 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.
•  

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Cont

• 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.

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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.

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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.

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• 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.

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• 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.

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• Tsunami Hazard Assessments
• An updated national tsunami hazard assessment has
  not yet been implemented. This is a planned
  activity in SMDs 2005/2006 annual management
  plan.
• Regional Cooperation
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• 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.

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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

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More information.TSUNAMI

• PACIFIC TSUNAMI WARNING CENTER (PTWC)
• Earthquakes are obtained from internet from NEIC.
• 1. Earthquakes gt6.5 and lt7.5mag or lt 7.0 in the
  Aleutian Islands Information Bulletin is issued
  by PTWC.
• 2. Earthquakes gt 7.5 (gt7.0 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.

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More information.TSUNAMI

• TRAVEL TIMES FOR TSUNAMI WAVE FROM PERU
  EARTHQUAKE IN JUNE 2001(SEA LEVEL AND CLIMATE
  MONITORING PROJECT COUNTRY REPORT MARCH 2003)

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More information.TSUNAMI

• TSUNAMI WAVE DUE TO PERU EARTHQUAKE (SIMULATED
  AMPLITUDE)

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More information..TSUNAMI

• APIA SEA LEVEL IN RESPONSE TO PERU EARTHQUAKE
  (JUNE 2001)
• PEAK TO TROUGH AMPLITUDE 30 CM
• (SLCMP- COUNTRY REPORT - MARCH 2003)

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• Thank you for your attention
• Faafetai tele lava