News

Japan earthquake “400 times bigger” than New Zealand quake

(11 March 2011)

The magnitude of today's Japan earthquake is 400 times more powerful than last month's quake in New Zealand, according to a Durham University Earth Scientist.

The 8.9 magnitude earthquake which struck just west of Japan is likely to be the largest to affect the region since historical records began.

The resulting tsunami could also affect islands such as Hawaii and reach as far as South America, Bob Holdsworth, Professor of Structural Geology, at Durham, said.

Professor Holdsworth said: "Japan is one of the most dangerous seismically active regions in the world and the constant threat of earthquakes and associated hazards such as tsunami (itself a Japanese word meaning 'harbour wave') has strongly shaped the development of Japanese culture and infrastructure over many hundreds of years.

"The magnitude of this event is staggering: it is almost 400 times more powerful that the recent Christchurch earthquake in New Zealand and nearly one hundred times more powerful that the 2010 Haiti earthquake. It is slightly smaller than the Sumatra earthquake of 2004, a magnitude 9.1 event. These last two events combined killed over 500,000 people.

"Yet of all the countries in the world it could strike, Japan is amongst the very best prepared. Had this not been the case the effects of this earthquake would have been even more devastating.

"Japan lies on one of the most active parts of the Pacific 'Ring of Fire', a 40,000 km long belt of seismicity and volcanoes that surrounds the Pacific Ocean. It runs from New Zealand, northwards along the eastern side of Asia - through Japan, curving up and round to Alaska and down southwards along the western edges of North and South America.

"Like the Sumatra earthquake, which was another subduction-related event, the greatest amount of damage and loss of life will come from the effects of the tsunami rather than being due to the direct physical shaking associated with the earthquake and its many associated aftershocks.

"It is much more difficult - perhaps impossible - to withstand the effects of a ten metre high tsunami wave. We only have to wait and see whether the waves affect other regions of Asia and islands such as Hawaii. The waves could reach as far as South America."