In this video Garth Archibald explains the use of a laser to monitor rockfall hazards in built up areas around Christchurch City:
In the second video, Chris Massey analyses rock fall trajectories in the Port Hills to calculate future risks to housing:
just curious, were there any strange indicators before the earthquake?
such as; dead birds, animals migrating that don't normally do so? etc.
I ask because inthe states (here)
in the area by the New Madrid fault there were reports of hundreds of dead birds in states
surrounding, dead fish washing onto shores http://www.msnbc.msn.com/id/40887450/ns/us_news-environment/#
there is question that this could be linked to the Nw Madrid becoming increasingly active. the new madrid being 6 times greater than the San adreas and would be trouble with a capital T, if it began to go.
we have seen that nature will warn us if there is a disaster on the brink ie. tsunamis, i have learned to watch nature in the event of a
severe weather outbreak,for instance if i were to see a group of cattle huddling, there is going to be trouble. no birds singing, dead silence. So- the same surely could be said of earthquakes. Its just that we have become such a world of noise that often we do not see or hear what nature is trying to tell us.
peace,& love to those in NZ.
Excellent videos but having talked to eye witnesses in the port hills sub divisions the accounts tell of rock being literally blasted off the face of the bluff, some simply fell away whilst other rock was literally blown off the face, this horizontal acceleration may have thrown large boulders a great distance away from the bluff before they even had a chance to bounce.
One thing I don't quite understand is that the earthquake "loosens" rocks given that we have had quakes in the past.
Having said that it must have taken a long time to form Shag rock prior to the earthquake.