• Question: Are there currently any geophysical models/theories regarding whether one earthquake can effectively cause another to happen (such as a possible link between the recent New Zealand and Japan earthquakes)?

    Asked by kraknor to Adam, Geoff, Rob, Sheila, Suzie on 23 Mar 2011 in Categories: .
    • Photo: Suzie Sheehy

      Suzie Sheehy answered on 21 Mar 2011:

      Hi there, great question and I wish I knew the answer. I don’t know much about geology so I don’t have the answer to this one – but I imagine that the shifting of tectonic plates which causes earthquakes makes them related… though whether one can ’cause’ another I don’t know.

    • Photo: Adam Tuff

      Adam Tuff answered on 21 Mar 2011:

      Quite possibly – they are afterall on the same plate, and I would be surprised if there isn’t a correlation – on the other hand that region, the so called “ring of fire” is extremely active, so they may have just been two very close, distantly related events.

      With regards to predicting earthquakes, there’s nothing that I know of that can predict earthquakes in the future, apart from pre-shocks, but they give very short notice. I think it would be very hard to deduce what’s happening under the plates to begin with.

    • Photo: Sheila Kanani

      Sheila Kanani answered on 22 Mar 2011:

      Good idea, I’m not sure if there are any models about this but I bet all the earthquake scientists are certainly aware that this could be a possibility!

    • Photo: Robert Simpson

      Robert Simpson answered on 23 Mar 2011:

      I’m not sure i know enough about this. i think though that tectonic plates are generally large enough to absorb the effects of earthquakes over the scale of the whole plate. i suppose with a small plate though it could be possible to have a big quake on one side of a quake cause a tremor on the other side – but I am not a geologist by any means.

Comments

  • Photo: David

    David commented on :

    Good question – the answer is yes, there are theories about links between earthquakes; but no, there was no link between Christchurch and Japan.

    When there is an earthquake, there is a release of stress along the part of the fault that fractures. This can, in turn, lead to stress changes at the ends of the fault – outside of which, nothing moved. It is a fairly frequent observation that sometimes earthquakes occur in a time-predictable sequence. So after a big quake, the next one releases stress at one end of the first fault; then another.. and so on. In the case of Japan, there was a 7.2 quake a little north of Tokyo (offshore) on March 9th; then the main shock happened on March 11th, a bit further north again. The rupture on 11 March stopped at the edge of the region where stress had been released 2 days earlier. This is a good example, with hindsight, of a foreshock (Mar 9) mainshock (Mar 11) sequence, where it looks as though the foreshock changed the regional stress patterns enough to promote the very large quake two days later.

  • Photo: David

    David commented on :

    Christchurch – very destructive, but ‘only’ a 6,3 mag earthquake. This is too small, and too far away to have affected Japan.