Small sensors installed in most smartphones and laptops
are sensitive enough to detect moderate and large earthquakes - greater than
magnitude 5 - a new study suggests.
A tiny chip used in smartphones to adjust the
orientation of the screen could serve to create a real-time urban seismic
network, easily increasing the amount of strong motion data collected during a
large earthquake, researchers said.
Micro-Electro-Mechanical System (MEMS) accelerometers
measure the rate of acceleration of ground motion and vibration of cars,
buildings and installations.
In the 1990s MEMS accelerometers revolutionised the
automotive airbag industry and are found in many devices used daily, including
smartphones, video games and laptops.
Antonino D'Alessandro and Giuseppe D'Anna,
seismologists at Istituto Nazionale di Geosifica e Vulcanologia in Italy,
tested whether inexpensive MEMS accelerometers could reliably and accurately
detect ground motion caused by earthquakes.
They tested the LIS331DLH MEMS accelerometer installed
in a smartphone, comparing it to the earthquake sensor EpiSensor ES-T force
balance accelerometer.
The tests suggest that the MEMS accelerometers can
detect moderate to strong earthquakes - greater than magnitude 5 - when located
near the epicentre.
The device produces sufficient noise to prevent it from
accurately detecting lesser quakes - a limitation to its use in monitoring
strong motion.
D'Alessandro and D'Anna note that the technology is
rapidly evolving, and there will soon be MEMS sensors that are sensitive to
quakes less than magnitude 5.
The real advantage, say the authors, is the widespread
use of mobile phones and laptops that include MEMS technology, making it
possible to dramatically increase coverage when strong earthquakes occur.
The current state of the MEMS sensors, suggest the
authors, could be used for the creation of an urban seismic network that could
transmit in real-time ground motion data to a central location for assessment.
The rich volume of data could help first responders
identify areas of greatest potential damage, allowing them to allocate
resources more effectively.
The study was published in the Bulletin of the
Seismological Society of America (BSSA).
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