TITLE:
Evidence of Correlation between High Frequency Geomagnetic Variations and Seismicity in the Caribbean
AUTHORS:
Bladimir Moreno, Eric Calais
KEYWORDS:
Caribbean Seismicity, Conductivity Response, Geomagnetic Storms, Hourly Earthquakes Frequency, Electromagnetic Induction, Eddy Currents, Geomagnetic Field
JOURNAL NAME:
Open Journal of Earthquake Research,
Vol.10 No.2,
April
22,
2021
ABSTRACT: An analysis between the hourly distribution of
earthquakes in three areas of the Caribbean and the high-frequency variations
of the geomagnetic field is presented. The number of earthquakes selected for
each zone is between 10,000 and 43,000, which guarantees a statistically
significant distribution. The hourly distributions of seismicity in all areas
show a bay-shape distribution with a significant increase in the number of
earthquakes at night, from 11 PM to 5 AM. For example, in eastern Cuba 36.7% of
earthquakes occur at that time, representing 11.7% over 25% in the absence of
any time preference. Geomagnetic disturbances were compiled from several years
to be able to make a statistically significant hourly distribution of their
occurrence, being determined by sudden changes in the magnetic field at a short
period of 1 minute. In this sense, geomagnetic data were processed between the
years 2011-2016, recorded by the geostationary satellite GOES13 and the
magnetic ground station SJG in San Juan, Puerto Rico. The result shows a significant correlation between hourly earthquakes
distribution and high-frequency geomagnetic variations. The time-varying
conductivity response of Earth’s interior also correlates with seismicity. The
theory behind this correlation could be related to the piezoelectric phenomena
and the electromagnetic force induced when the magnetic field is disturbed.