A
regional tsunami watch was
in effect for all areas of the Indian Ocean," the Pacific Tsunami Warning Center said on its website, adding that the epicentre of the quake was 107 miles west of Misha on the Nicobar Islands at a depth of 20.5 miles.
By about 2:30 am, the PTWC said on its website that the
area of watch had been reduced to India.
"Due to the downward revision of the earthquake magnitude as well as additional analysis of the earthquake the area of watch is now reduced to only India," the PTWC said in a bulletin meant for all areas in the Indian Ocean.
While recording the earthquake, the PTWC said that there was a possibility of a local tsunami that could affect coasts located "no more than a hundred kilometres from the earthquake epicentre."
Please explain to me the highlighted parts.
Though I know "in effect" generally means "in force". Also I know the meaning of tsunami.
Source :
http://www.hindustantimes.com/Underwater-quake-off-Nicobar-triggers-tsunami-fears/Article1-557022.aspx