News

Alex Densmore featured in The Guardian

(14 March 2011)

Dr Alex Densmore, Director of Hazards research in IHRR, was featured in an article in The Guardian about how aftershocks can occur after the 9.0 magnitude earthquake in Japan.

The Sendai earthquake in Japan, the country's largest on record, caused a number of secondary hazards, especially the tsunami which has completely devastated parts of the country.  Aftershocks can occur in some cases months after the initial earthquake and can have a cumulative effect on the landscape causing other hazards.

According to Dr Densmore:

"The bigger the earthquake, the bigger the change in stress and the more aftershocks. There are many more aftershocks than after the Sichuan earthquake in China [in 2008], but that was magnitude 7.9 and this was 8.9. You have 30 times more energy released."

"It's not about how much the ground shakes, but how much energy is released, because that's what gives other parts of the fault increased stress.

"That's what aftershocks are: areas around [the location of the original shock] relieving stress. But those also affect other parts of the fault: you get a cascade effect."

Read the full article on The Guardian's website:

http://www.guardian.co.uk/world/2011/mar/13/japan-earthquake-aftershocks-threaten-survivors

Dr Densmore was also quoted in New Zealand Sunday News.