Effect of Magnetic Storms on Low-Frequency Seismic Noise

Abstract—The response of seismic noise in the minute range of periods to the strong magnetic storms is studied. The noise is analyzed from the records by IRIS broadband seismic stations located in the different regions of the world. The minute variations in the X-, Y-, Z-components of the magnetic field at different observatories were obtained through the INTERMAGNET world data system. Seismic pulses that emerged at rapid variations in the rate of change of the magnetic field components dX, dY, dZ are detected. The pulses have the amplitudes of ~2 μm and duration of a few min. The high variability in the ratio of the amplitude of seismic pulses to the magnitude of changes in dHx, dHy, dHz indicates a nonlinear process. The amplitudes of seismic pulses are approximately identical at the stations located in the seismically active or quiet regions. The properties of the pulses also do not depend of weather conditions. The pulses are revealed in the records by all seismic stations located in the continents. In the records from the identical stations located on the volcanic islands in the deep part of the Pacific, such pulses are not detected. It is hypothesized that abrupt changes in the electromagnetic field during a storm act as a trigger for the release of energy accumulated in the Earth.