| Communications and Development |  |
Published by Communications and Development
A UC project to predict the location and volume of coseismic landslides has been awarded $30,000 funding by the Earthquake Commission (EQC).
Associate Professor Tim Davies (Geological Sciences) will develop and test a methodology for identifying the most probable source locations and volumes of earthquake-generated landslides in seismically active mountain terrain. This will be done by using available topographic and geological information that has been gathered recently by former PhD student Flo Buech.
Flo recorded earthquakes at Little Red Hill, a small, steep, rocky mountain near Lake Coleridge.
“Natural earthquakes were measured and recorded at both the bottom and the top of the mountain and it was found that at the top, the intensity of the shaking increased by a factor of up to 11, which is higher than ever recorded before and was a bit of a surprise,” Professor Davies said.
Flo attempted to reproduce this same behaviour in a 1:1000 scale model in the laboratory, “but it didn't work very well, so the next step was to do this by computer modelling”.
With the EQC funding, PhD student Ali Bazgard will use the computer program Particle Flow Code 3D (PFC3D) to build a virtual mountain out of small spherical particles stuck together in a particular way that can be specified to make sure that they behave in the same way as a mountain.
“Then we can model the equivalent of an earthquake shaking the mountain and from that gather information. This includes measuring what parts of the mountain are most stressed to determine which shape and size will fall when shaken,” Professor Davies said.
Large amounts of rock can break up very intensely and travel large distances, he said.
“We are now in a position that if we know the amount that is going to fall and where it is going to fall from, we can predict where that debris is going to go, so we can plan ahead.
“Because of the data that we have gathered from the field we can test the model and plan where the best place is to build roads and bridges — and it might not be the most obvious place.”
Landslides as the result of an earthquake cause a lot of damage to the landscape and infrastructure. The largest landslide known in Canterbury happened 500 years ago when “500 million cubic metres fell off the back of Porter Heights skifield”.
“The next big earthquake on the Alpine Fault is overdue, so we are expecting a very large one to occur — very much like the recent Sichuan earthquake in China.”
For further information please contact:
Jane Lucas
Communications Officer
University of Canterbury
Tel: +64 3 364 2072
Fax: +64 3 364 2679
jane.lucas@canterbury.ac.nz