Groundwater extraction linked to Lorca earthquake
The 2011 Lorca
earthquake was triggered by excessive extraction of water from a nearby
natural underground reservoir, which moved the Earth's crust, suggests a
new study.
The moderate earthquake on May 11, 2011, measuring 5.1, had killed nine
people and caused significant localised damage in the Region of Murcia,
Spain.
The study led by Pablo Gonzalez of University of Western Ontario and his team has been published in journal Nature Geoscience.
The researchers reckoned
that the quake was related to a drop in the level of groundwater in a
local aquifer, which can create pressure at the Earth's surface.
Researchers, who used satellite data to test the theory, found that the
earthquake was correlated to changes in the Earth's crust caused by a
250 metre drop in the natural groundwater level over the last five
decades due to groundwater extraction.
The new findings suggest that human-induced stress on faults like the
one near Lorca, known as the Alhama de Murcia Fault, can not only cause
an earthquake but also influence how far the fault will slip as a
result.
"We cannot set up a rule just by studying a single particular case,
but the evidence that we have collected in this study could be necessary
to expand research in other future events that occur near ... dams,
aquifers and melting glaciers, where you have tectonic faults close to
these sources," Gonzalez said.
In an accompanying article, Jean-Philippe Avouac of California Institute
of Technology said the implications could be far-reaching "if ever the
effect of human-induced stress perturbations on seismicity is fully
understood".
"For now, we should remain cautious ... We know how to start
earthquakes, but we are still far from being able to keep them under
control," Avouac wrote.
No comments :
Post a Comment