The Great Sumatran fault ( a strike-slip fault ) , and the Sunda megathrust ( a subduction zone ) , run the entire length of the island along its west coast . On 26 December 2004 , the western coast and islands of Sumatra , particularly Aceh province , were struck by a tsunami following the Indian Ocean earthquake . This was the longest earthquake recorded , lasting between 500 and 600 seconds . More than 170,000 Indonesians were killed , primarily in Aceh . Other recent earthquakes to strike Sumatra include the 2005 Nias – Simeulue earthquake and the 2010 Mentawai earthquake and tsunami
2010 Mentawai earthquake and tsunami
2010 Mentawai earthquake and tsunami
Sumatra