Tsunami Early Warning Tsunami Early Warning SystemSystemSRI LANKASRI LANKA

Lalith ChandrapalaLalith Chandrapala

Sarath WeerawarnakulaSarath Weerawarnakula

Early Warning SystemEarly 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 Department of Meteorologyof Meteorology was designated as the Tsunami Early Warning Tsunami Early Warning CentreCentre for 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).

Early Warning SystemEarly Warning System in Sri Lanka

• Seismic Information is Seismic Information is received fromreceived 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

Early Warning SystemEarly Warning System in Sri Lanka

Early Warning SystemEarly 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 @ GSMB

5-10 minut

esNo No

California Integrated Seismic Network (CISN)

10 minut

es

Yes (Preliminary)

Yes (Preliminary)

Pacific Tsunami Warning Centre (PTWC)*

15-20 minut

esYes Yes

Japan Meteorological Administration (JMA)*

Over 30

minutes

Yes Yes

* through Advisories* through Advisories

Three Tide Gauges atColomboKirinda

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

Early Warning SystemEarly Warning System in Sri Lanka

Early Warning SystemEarly Warning System in Sri Lanka

• Warnings/Advisories on Tsunami are Warnings/Advisories on Tsunami are issued based on seismic data. issued based on seismic data.

• However, Sea Level Information However, Sea Level Information from Indonesian gauges, particularly from Indonesian gauges, particularly the gauge at the gauge at SibolgaSibolga,, is used for is used for guidance in addition to the guidance guidance in addition to the guidance provided by PTWC and JMA.provided by PTWC and JMA.

• Advisory is issued within 30 Advisory is issued within 30 minutes of the Earthquakeminutes of the Earthquake

Magnitude of oceanic EQ

6.5 to 6.9EWC keeps close watch on Tide gauge data available in the internet (Hawaii SLC). No official bulletins are issued

7.0 to 7.4Earthquake 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

How Warnings are Issued ……

Once a Bulletin is issued ……

Dissemination to relevant Dissemination to relevant authorities/institutions and authorities/institutions and

communitiescommunities

through

1.1.Media (Radio and Media (Radio and Television)Television)

[most effective and efficient!]

2. through Regional 2. through Regional Police StationsPolice Stations

3. Military 3. Military Communication Communication SystemsSystems

EarthquakeEarthquake

Early Warning CentreEarly Warning CentreSeismic Seismic InfoInfo

• GSMB Info

• CISN• PTWC• JMA

Sea Level Info

15 minutes15 minutes

Issue of Issue of Advisory in Advisory in 30 mnts.30 mnts.

Media – direct to communities

Police (Police HQ to Regional Police Stations and then to communities)

Military communication system to communities

If people receive the warningIf people receive the warning in 45 minutes,in 45 minutes,

then they have over then they have over one hour to respondone hour to respond

Educating Public is very Educating Public is very important !important !

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

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!However, the present situation is different!

Educating Public is very Educating Public is very important !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!However, the present situation is different!

A good example

On 28th March 2005

Magnitude 8.7Magnitude 8.7

Within 55 minutes of the issuance Within 55 minutes of the issuance of the Advisory Bulletin, all people of the Advisory Bulletin, all people

evacuated.evacuated.

Evacuation on 28Evacuation on 28thth March 2005 March 2005

was not was not

one hundred percent idealone hundred percent ideal

BUTBUT

evacuation was completedevacuation was completed

within within

55 minutes55 minutes

Kalmunai, Eastern Sri Lanka on 28Kalmunai, Eastern Sri Lanka on 28thth March 2005 March 2005

Timeline – 28Timeline – 28thth March 2006 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 mintsTime to issue advisory - 45 mints

Time between issue of advisory and Time between issue of advisory and evacuation completion - 1 hr 40 mntsevacuation completion - 1 hr 40 mnts

Time between start and end of evacuation – Time between start and end of evacuation – 55 mnts 55 mnts

Posters and Leaflets have been distributed Posters and Leaflets have been distributed …….…….

Thank You