Tsunami Early Warning System SRI LANKA

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Tsunami Early Warning SystemSRI LANKA

• Lalith Chandrapala
• Sarath Weerawarnakula

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Early Warning System in Sri Lanka

• No Early Warning System for Tsunami prior to
  26-12
• Different Government Institutions mandated to
  monitor and issue Early Warnings in the case of
  different hazards
• (e.g. Meteorology for weather related, NARA for
  Oceanic, GSMB for seismological, NBRO for
  landslides etc.)
• After 26-12, Department of Meteorology was
  designated as the Tsunami Early Warning Centre
  for Sri Lanka.

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Early Warning System in Sri Lanka

• A Technical Committee representing all
  stakeholders appointed to coordinate the
  activities of the EW Centre.
• Connected with Pacific Tsunami Warning Centre and
  Japan Meteorological Agency thro telephone/fax
• Technical Committee will become the TAC on Early
  Warning of DMC once an EWC is established at the
  Disaster Management Centre (DMC).

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Early Warning System in Sri Lanka

• Seismic Information is received from
• California Integrated Seismic Network (supplied
  from IOC)
• Pallekele GSMB Seismic Station (from the display
  at GSMB HQ)
• Pacific Tsunami Warning Centre - Advisories
• Japan Meteorological Administration - Advisories

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Early Warning System in Sri Lanka
Usually the EWC receives information about
seismic events in the following order
Source of information Minutes after the event Location Info. Magnitude Info
Seismic Monitoring Centre _at_ GSMB 5-10 minutes No No
California Integrated Seismic Network (CISN) 10 minutes Yes (Preliminary) Yes (Preliminary)
Pacific Tsunami Warning Centre (PTWC) 15-20 minutes Yes Yes
Japan Meteorological Administration (JMA) Over 30 minutes Yes Yes
through Advisories
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Early Warning System in Sri Lanka
Three Tide Gauges at Colombo Kirinda
and Trincomalee (Maintained by
NARA) Information on sea level changes available
to EWC only through the Internet. Hawaii Sea
Level Centre Web site NARA website
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Early Warning System in Sri Lanka

• Warnings/Advisories on Tsunami are issued based
  on seismic data.
• However, Sea Level Information from Indonesian
  gauges, particularly the gauge at Sibolga, is
  used for guidance in addition to the guidance
  provided by PTWC and JMA.
• Advisory is issued within 30 minutes of the
  Earthquake

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How Warnings are Issued
Magnitude of oceanic EQ
6.5 to 6.9 EWC keeps close watch on Tide gauge data available in the internet (Hawaii SLC). No official bulletins are issued
7.0 to 7.4 Earthquake Information Bulletin is issued informing about the occurrence of the Earthquake.
7.5 to 7.7 Earthquake Information Bulletin is issued indicating the location, magnitude of the Earthquake, and requesting the public to be ready for evacuation at short notice.
Over 7.8 Tsunami Advisory Bulletin is issued requesting public in vulnerable regions to evacuate immediately
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Once a Bulletin is issued
Dissemination to relevant authorities/institutions
and communities

• Media (Radio and Television)
• most effective and efficient!
• 2. through Regional Police Stations
• 3. Military Communication Systems

through
10
15 minutes
Early Warning Centre

• Seismic Info
• GSMB Info
• CISN
• PTWC
• JMA

Earthquake
If people receive the warning in 45
minutes, then they have over one hour to respond
Sea Level Info
Issue of Advisory in 30 mnts.
Media direct to communities Police (Police HQ
to Regional Police Stations and then to
communities) Military communication system to
communities
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Educating Public is very important !
Over 93.5 of the vulnerable coastal population
in Sri Lanka have not even heard about
tsunami prior to last episode. (ADPC, 2005)
However, the present situation is different!

• A large number of seminars/workshops/meetings
  have been conducted in vulnerable areas

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Educating Public is very important !
Over 93.5 of the vulnerable coastal population
in Sri Lanka have not even heard about
tsunami prior to last episode. (ADPC, 2005)
However, the present situation is different!
A good example On 28th March 2005
Magnitude 8.7
Within 55 minutes of the issuance of the Advisory
Bulletin, all people evacuated.
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Evacuation on 28th March 2005 was not one
hundred percent ideal BUT evacuation was
completed within 55 minutes
Kalmunai, Eastern Sri Lanka on 28th March 2005
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Timeline 28th March 2006
28/2210 hrs SLST Earthquake in
Indonesia 28/2220 hrs SLST PALK station pickup
unusual wave pattern 28/2230 hrs SLST PTWC
Bulletin Number 1 received at EWC 28/2255 hrs
SLST Tsunami Advisory issued Evacuation
begins 28/2350 hrs SLST Evacuation completed,
Tide Watchers deployed by SLN 29/0300 hrs
SLST All Clear issued by EWC
Time to issue advisory - 45 mints Time between
issue of advisory and evacuation completion - 1
hr 40 mnts Time between start and end of
evacuation 55 mnts
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Posters and Leaflets have been distributed .
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Thank You