A tsunami is a series of large waves of extremely long length and generated by a violent, impulsive undersea disturbance or activity near the coast or in the ocean. When the sea floor is suddenly raised or dropped by an earthquake, big tsunami waves can be formed. The tsunami in the recorded time period with the highest death toll happened in the Indian Ocean in December 2004 (more than 230.000 people died). On December 26, 2004, at 7:58 am local time an undersea earthquake with a magnitude of 9.1 approximately 160 km west of the shores of Sumatra (Indonesia) and 30 km below the sea surface triggered tsunamis in the Indian Ocean. They hit the coasts of countries East and West of the epicenter, among them Indonesia, Sri Lanka, India, Thailand, the Maldives, the Seychelles, Myanmar, Malaysia, Bangladesh and reaching as far as Somalia and Tanzania on the African coastline over 6000 km away.
According to recent studies an increased occurrence of such events due to climate change and global warming is highly likely.
The coastal populations of the affected countries were hit the hardest, suffering deaths, injuries, displacement and the destruction of their livelihoods. Indonesia was affected most, with an estimated number of 170,000 casualties and approximately 500,000 displaced people.
There are very particular demographic patterns to the deaths: According to an Oxfam report, four times more women were killed than men, as they were waiting on beaches for fishermen to return, or at home looking after their children at the time the tsunami hat.
But among the victims were also people from abroad, though they count for a small share of the hundreds of thousands who died: a number of 2,307 is reported to have died or gone missing, most of them tourist who went to South-East Asia for their Christmas holidays. The largest share of citizens from abroad reported dead were from Western Europe. Sweden alone lost 554 citizens in the disaster (counting for 58.10 deaths per one million inhabitants, the largest share of a foreign country compared to their population), while Germany had 539 identified victims (6.75 deaths per million inhabitants).