19December 2021 ESRFnews
SHORTLY before 8.30 a.m. on Saturday 14 August this year, the people of Petit-Trou-de-Nippes, a com-mune in the south-west of Haiti, felt the earth fall from beneath their feet. An earthquake of magnitude 7.2 had nucleated 10 km underground, generating violent shaking throughout the country, and even 350 km away, in Jamaica. At least 136,000 buildings were destroyed and 2200 people killed, making it the deadliest quake and indeed the deadliest natural disaster of the year so far. No-one knew that the Haiti quake was coming. No-one
ever knows when earthquakes are coming. Despite all the advances in geophysics over the years, the best scientists can do is to identify which regions are most prone to
The ESRF EBS s new BM18 beamline is giving new hope for the physical understanding of earthquakes.
earthquakes, based on their proximity to fault lines, and whether any of these regions is due a significant earth- quake, based on how frequently it has experienced quakes in the past. There are major quakes expected in New Zealand, Turkey, and in California, US, for instance but when exactly in the next century, we just don t know. The trouble is that, originating tens of kilometres
underground, earthquakes cannot be studied directly. Geophysicists can simulate them in the lab by placing small rock samples under great pressure, and listening for the resulting propagation of fractures with microphones. Lab-based X-ray sources give a clearer picture, being able to expose even silently propagating fractures. But
Like all earthquakes, the Haiti quake in August this year was unpredictable.