Originally Posted by bbc
This was one of the most powerful earthquakes in Indonesia since the one which caused the Asian tsunami in 2004.
That measured 8.9 and struck under the sea near the northern Sumatran province of Aceh, triggering a tsunami that killed more than 220,000 people around the rim of the Indian Ocean. Our correspondent says quakes on this scale are rare and memories of 2004 have made the country terrified of a repeat.
how long does it take to know if the earthquake is conna create a tsunami?