There is a higher probability of Tsunami in Atlantic similar to that of Dec 2004 Tsunami in Indian Ocean.On November 1,1755 - A Tsunami in Atlantic Ocean wiped out the entire city of Lisbon in Portugal!!And the Tsunami's in Atlantic ocean may also affect nearly the whole of US East Coast,Canada and Europe.Added to this there is a fault line which runs through the centre of Atlantic ocean and there has been not a major earthquake of over 7.5 in the last 90 years.So there is every possibility of a Tsunami in that region in future.
Each Tsunami alert notification would be accompanied by a siren sound and generally it would last for few seconds depending upon the category of alert.For highest alert,it would last for 15 seconds(7 seconds during daytime) and for other information bulletins the siren would last for 2 seconds.
Note:This app relies on PTWC Tsunami warnings for Caribbean sea.(Atlantic Ocean)