Tsunami warning

Researchers at TU Delft have created unique images showing the development of the earthquake in South East Asia last December using data captured from GPS systems.


In the past few years, the researchers have established an extensive network of about 45 scientific GPS stations in South East Asia. And they used data from the GPS systems to accurately compute the size and direction of the deformations resulting from the earthquake with an accuracy of a few millimetres.


Their research shows that the Thai island of Phuket moved 27 cm directly after the quake, which is more than twice the distance initially predicted. That value has now increased to about 40 cm.


And for the first time, the deformations of the tectonic plates during the ten minutes the quake lasted have been made visible. The scientists have visualised this in an impressive animation, which can be found at their website at http://www.deos.tudelft.nl.


Based on the GPS measurements, a number of new conclusions about the quake have been drawn. One is that the rupture plane was at least 1000 km longer than had been initially predicted based on seismological measurements. Another is that the force of the quake was not 9.0, but 9.2 to 9.3 on the Richter scale, approximately twice as strong.


The researchers say that if all the GPS stations were to relay their measurements in real-time, which they say is technically possible, the GPS data could be used to generate a model of a possible tsunami within about half an hour. If necessary, a warning could then be issued.