Gravity changes used for early detection of earthquakes and determination of their magnitude
Researchers from IPGP, CNRS, Caltech and Paris Diderot University have observed changes in the gravitational field produced by earthquakes before the arrival of seismic waves (propagating with speeds between 3 to 10 km/s). These gravity changes (which are conceptually different from the recently detected gravitational-waves) can be used as a new potential information carrier, helping in the early detection of major earthquakes or tsunamis and in the determination of their magnitude.
This work, based on data from the 2011 Tohoku Japanese earthquake (magnitude 9.1), opens new perspectives in the seismology. Further work is required to improve the detection of this weak gravity signal, especially for smaller earthquakes. New instruments can benefit from the technology developed in the field of the detection of gravitational waves coming from distant Universe. You can learn more (below) on this joined work between seismologists and astrophysicists published in Science on December 1st.