Feature - Surfing for earthquakes
The very structure of the Earth controls how earthquakes travel and the amount of damage they cause. Therefore, a clear picture of this structure would be extremely valuable to earthquake planners — but it requires the analysis of huge amounts of data.
To help, the RAPID team developed a system that performs the seismologists’ data-crunching, and have made it easy to use by relying on an interface familiar to all scientists: a web browser.
Seismologists measure vibrations in the Earth at hundreds of observatories across Europe, which allows them to study earthquakes as they travel across countries and continents. By measuring the speed and strength of the vibrations at different sites, deductions can be made about the type of ground they have travelled through.
The problem with earthquakes is that they don’t occur when and where you need them.
Fortunately for researchers, earthquakes aren’t the only things that cause vibrations: road traffic, waves pounding on the beach, and even wind and thunder can also cause detectable vibrations. These vibrations, known as noise, may lack the strength of earthquakes but they compensate by being available in huge numbers. Consequently, if enough noise is analyzed, it is possible to build up information about the Earth’s structure.
The analysis is not without complications, however. “You can use noise to analyze the Earth’s structure, but you need to analyze huge amounts of data — and that’s nearly impossible on standard [computers],” explained Andreas Rietbrock, a professor of seismology at the University of Liverpool who helped develop the new system with the Rapid team.
Attacking the problem from both ends
The volume of data was not an issue. The Orfeus foundation (also known as the Observatories and Research Facilities for European Seismology) collects seismic data from around Europe and makes it available for analysis through websites like the Earthquake Data Portal.
However, only a few organizations have the resources and technical know-how needed to process this vast store of data.
Accordingly, Orfeus asked the RAPID team to develop a system that would allow any seismologist to analyze seismic data. “We don’t want [seismologists] to have to study how to access [remote] computer power and data” said Torild van Eck, secretary general of Orfeus. “RAPID is, for us, a tool to hide the tricky part of getting, steering and manipulating data”.
For Orfeus, the team developed a web portal. This takes all the complex computing needed for seismic analysis and hides it behind a standard web browser. By presenting all of the analysis tools in such a familiar environment, any seismologist — even the most technophobic ones — can use the system.
The web portal allows even the smallest seismology groups to perform the kind of analyses previously limited only to organizations that could afford their own supercomputers. By making this analysis easy, RAPID and Orfeus have brought complex research program into the hands of many more seismologists. More seismologists working together means that results are produced faster, and that means we could soon benefit from a better understanding of the ground beneath our feet.
“It’s been great working with the seismologists, because as a community they’re very open to trying out new ways of working. And they have really pushed the boundaries of our technology” said Jano van Hemert, leader of RAPID.
The team will build on this work with help from a grant from the UK’s Natural Environment Research Council, which has provided funding to explore whether it is possible to predict earthquakes and volcanic eruptions.
—Simon Hettrick, for iSGTW. At the other end of the globe, you can see a simulation of an earthquake in California's San Andreas Fault in this video presented by Torild VAN ECK from EPOS ESFRI project during Wednesday's environmental sciences ESFRI session at the EGI Technical Forum. For more on California earthquake simulations, see 4 February 2009 iSGTW story "Anticipating the Big One."