What is the difference between a ‘Tsunami Watch’ and a ‘Tsunami Warning’? Should we panic for Tsunami WATCH..??


The oceanic Earthquake of magnitude of 8.7  near Sumatra occurred at the worst possible time for Sri Lankan who are getting ready for Avurudu. Tsunami sirens were activated and evacuation orders were issued immediately.

It is always better to be ‘worry’ than ‘sorry’; but when I was checking the Pacific Tsunami Warning Centre http://www.ptwc.weather.gov, they had it just as a ‘Tsunami WATCH’ but not a ‘Tsunami WARNING’ throughout. (I started checking http://www.ptwc.weather.gov only after 1 hr, so pls update if anybody has seen a Tsunami WARNING on this site that is the center of distributing Tsunami Alerts)

“At the time of a Tsunami WARNING only, the public should be informed of the ensuing danger by sirens and the emergency broadcast system” as per the http://www.tsunami.org.. But yesterday, sirens were activated and evacuation orders has been issued for a mare Tsunami WATCH..?

Again, it is always better to be worry than sorry, and it was required to put everybody on alert. But does evacuation and sirens is an act of over-cautiousness creating unnecessary panic..? Public in the future might be taken it light, if sirens always used in cases of Tsunami WATCHEs..?? (remember the story where a farmer jokingly shout that a wolf was fake and when the wolf came for real and he shout, nobody cared)

Perhaps there should be 2 levels of Tsunami Sirens- 1 for Tsunami WATCH and the other for Tsunami WARNING.

Here is the extract from http://www.tsunami.org/faq.html on differences between a Tsunami WATCH and a Tsunami WARNING.

“a Tsunami Watch is automaticaly declared by the warning centre for any any earthquake having a magnitude of 7.5 or larger on the Richter scale and located in an area where a tsunami can be generated.

Notification of Civil Defense agencies begins, followed by limited public announcements by the local media. Data from sea level gauges is awaited for confirmation of the actual existence of a tsunami. Reports on wave activity from the locations nearest to the earthquake epicenter is requested by the warning center. If there is no observed tsunami activity, the Tsunami Watch is canceled.

If these stations report that a tsunami has been generated, a Tsunami Warning is issued for areas that may be impacted in the next three hours. At this time the public is informed of the ensuing danger by sirens and the emergency broadcast system. Evacuation procedures are implemented, and sea going vessels are advised to head out to sea, where in deep waters they will not be affected by the tsunami.”

To get latest alerts on Tsunamis, visit Pacific Tsunami Warning Centre:


Difference between ‘Tsunami WATCH’ and a ‘Tsunami WARNING’ :





2 Responses to “What is the difference between a ‘Tsunami Watch’ and a ‘Tsunami Warning’? Should we panic for Tsunami WATCH..??”

  1. Marianne Says:

    Never knew there was a difference! Thanks for the education and have a great Avurudu!

  2. Nalaka Gunawardene Says:

    Dear Malaka,
    Thanks for this piece – timely, informative, very useful. If the terminological differences between WATCH and WARNING become ambiguous in English, just imagine the far worse confusion that usually results when such terms are hastily — and imprecisely — translated into other languages such as Sinhala or Tamil. This is why I have advocated a language-neutral colour-coding system for this purpose.

    By the way, good to see you write on these wider topics. I, for one, have no interest in wildlife but am very interested in life going wild — as it did in much of Lanka on April 11!

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