1. Tsunami Early Warning System SRI LANKA
Lalith Chandrapala
Sarath Weerawarnakula

2. 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.

3. 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).

4. 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

5. 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 GSMB
5-10 minutes No
California Integrated Seismic Network (CISN)
10 minutes
Yes (Preliminary)
Yes (Preliminary)
Pacific Tsunami Warning Centre (PTWC)*
15-20 minutes
Yes
Japan Meteorological Administration (JMA)*
Over 30 minutes
* through Advisories

6. 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

7. 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

8. 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

9. through 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. If people receive the warning Issue of Advisory in 30 mnts.
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

11. 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

12. 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.

13. one hundred percent ideal
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

14. Time to issue advisory - 45 mints
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 mints
Time between issue of advisory and evacuation completion - 1 hr 40 mnts
Time between start and end of evacuation – 55 mnts

15. Posters and Leaflets have been distributed …….

16. Thank You