10 Years On: The Boxing Day Tsunami

On the 26^th December 2004 one of the largest earthquakes in the last century struck off the west coast of Sumatra. This resulted in one of the largest tsunamis seen in modern times affecting many countries surrounding the Indian Ocean including Indonesia, Sri Lanka, Thailand, Malaysia, India and Eastern Africa. It was the deadliest tsunami in recorded history killing over 220,000 people. Many bodies were lost at sea or buried in mass graves and not recorded meaning an accurate number will never been known. This disaster opened the world’s eyes to how destructive natural disasters can be and how vulnerable and unprepared countries are to these events. Since then significant improvements have been made to mitigate the effect of tsunamis, with modelling, prediction and warning systems introduced in many areas.

On 26^th December 2004 a large mega-thrust earth quake of M_W 9.3 struck the Sumatra-Andaman Region and resulted in the formation of numerous large tsunami waves which spread out across the Indian Ocean and devastating areas along the coasts. The earthquakes epicentre was 3.09^oN and 94.26^oE, 100km off the Sumatran coast and occurred along a fault line stretching from Indonesia to the Andaman Islands in the North where the Indo-Australian Plate was subducting beneath the Sunda and Burma sub-plates. 

The earthquake occurred due to the overriding plate becoming locked meaning bending and buckling was occurring of this plate, until there is an abrupt slip and the plate rebounds back (Fig.2) causing a large earthquake and displacing a large volume of water.(Stein and Okal, n.d.)

The area affected by the Tsunami was vast and even small displacements could be seen on the East Coast of South America. Image from Titov et al. 2005

The waves were 3-11m high and caused devastation, even today there are scars of the event on the coastlines.

Today an Early Warning Tsunami System has been implemented across the whole of the Indian Ocean and it is constantly monitored due to the risk of the tsunamis. 

It was one of the worst events in recorded history and today we remember all those people lost and those affected around the world, ten years on.

Stein, S., and Okal, E.A. (n.d.) Long period seismic moment of the 2004 Sumatra earthquake and implications for the slip process and tsunami generation [Online] Available at: < http://www.earth.northwestern.edu/people/seth/research/sumatra.html> [28.02.2012]

Titov, V., Rabinovich, A.B., Mofjield, H., Thompson, R., and Gonzalez, F. (2005) The Global Reach of the 26 December 2004 Sumatra Tsunami. Science. 309, pp.2045-2048.