Possible influence of Geomagnetic Sq variations on Earthquake events

  1. Kyushu University, Japan
  2. International Center for Space Weather Science and Education, Kyushu University, Japan

   The sun is the main source of energy to the solar system, and it plays a
   major role in affecting the ionosphere, atmosphere and the earth surface.
   The connection between solar wind and the ground magnetic pulsations has
   been proven empirically by several researchers previously (H. J. Singer et
   al., 1977, E. W. Greenstadt, 1979, I. A. Ansari 2006 to name a few).
   However a clear coupling mechanism was not established yet. In our
   preliminary statistical analysis on relationship between solar and seismic
   activities (Jusoh and Yumoto, 2011, Jusoh et al., 2012), we observed a
   high possibility of solar-terrestrial coupling on the tendency of
   earthquakes to occur during lower phase solar cycles which significantly
   related with solar wind parameters (i.e solar wind speed and solar wind
   input energy).

   To connect the solar impact on seismicity, we are considering
   electro-mechanical concept of electrodynamics principle during disturbed
   period (high solar wind input energy) as one of the possible physical
   mechanism. The basic concept was first introduced by G. Duma and Y. Ruzhin
   (2003). From the electrodynamics principle, the circular electric currents
   that flow in magnetic field will generate magnetic moment, MM, and
   possible to induce mechanical torque into underground of subduction zone
   before possibly triggering the earthquakes.

   In our analysis, the recorded Sq currents extracted from different ground
   magnetometer stations were analyzed during quite and disturbed periods of
   solar wind events. The analysis then extended to investigate any possible
   relationship with the occurrences of local earthquake events at different
   magnitudes and epicenter depths.

   In this analysis, solar wind parameters were obtained from the Goddard
   Space Flight Center, NASA via the OMNIWeb Data Explorer and the Space
   Physics Data Facility. Earthquake events were extracted from the Advanced
   National Seismic System (ANSS) database. The Sq currents were extracted
   from Magnetic Data Acquisition System (MAGDAS)/Circum Pan Magnetic Network
   (CPMN). This magnetometer arrays has been established by International
   Center for Space Weather Science and Education, Kyushu University, Japan.

   From the results, we observed significant correlations between solar wind
   input energy, Sq currents and earthquakes, where the higher amount of
   solar wind input energy corresponds to the enhancements of Sq currents
   amplitude and increase the tendency of localized earthquakes to occur.