Mega quakes occur more frequently when sun has fewer sunspots - 26th Sept 2011

The frequency of mega earthquakes increases during periods when the sun has fewer sunspots, a team of Japanese researchers has found.

The finding was made by a team led by Kiyofumi Yumoto, a researcher in space and earth electromagnetism at Kyushu University's Space Environment Research Center.

The March 11 Great East Japan Earthquake occurred when there were few sunspots. The latest research suggests that the sun's activity could influence movements beneath the earth's surface.

Sunspots gradually increase and decrease in number in a cycle of about 11 years, and cause changes in the earth's atmosphere. The research team investigated the possibility that they could also produce changes beneath the earth's surface, and compared data on the number of sunspots between 1963 and 2000 and the 327,625 earthquakes of magnitude 4 or more that occurred during this period.

The study found that 65 percent of the earthquakes with magnitudes between 4.0 and 4.9 occurred during the periods with the fewest sunspots (each lasting about two years). The figure was around the same for earthquakes with magnitudes between 5.0 and 7.9. However, the figure was higher for the 28 mega earthquakes with magnitudes in the 8.0-9.9 range, with 79 percent of them occurring during periods with the fewest sunspots.

When there are fewer sunspots, a phenomenon occurs in which solar winds, or streams of charged particles from the sun, get stronger an average of three to four times a month. Seventy percent of the earthquakes of magnitude 6.0 or stronger occurred at such times.

Solar winds that become stormy are known to be able to induce strong currents in power transmission lines, which can lead to major blackouts. Read More