Influences of Solar Cycles on Earthquakes

Abstract

This paper inspects possible influence of solar cycles on earthquakes through of statistical analyses. We also discussed the mechanism that would drive the occurrence of increasing of earthquakes during solar maxima. The study was based on worldwide earthquakes events during approximately four hundred years (1600-2010).The increase of earthquakes events followed the Maxima of Solar cycle, and also depends on the tectonic plate location. From 1600 until 1645 events increased during the Maxima in some of the tectonic plates as Pacific, Arabian and South America. The earthquakes analyzed during two grand solar minima, the Maunder (1645-1720) and the Dalton (1790-1820) showed a decrease in the number of earthquakes and the solar activity. It was observed during these minima a significant number of events at specific geological features. After the last minima (Dalton) the earthquakes pattern increased with solar maxima. The calculations showed that events increasing during solar maxima most in the Pacific, South America or Arabian until 1900. Since there were few records during these three centuries we needed additional analysis on modern data. We took the last four solar cycles events (1950-2010) and made similar calculations. The results agreed with the former calculations. It might be that the mechanism for the Sun-Earth connection relies on the solar wind speed. In both records (1600-1900) and (1950-2010) the results showed a significant increase in earthquakes events in some of the tectonic plates linked to solar maxima. The Solar wind energy striking the Earth's magnetosphere affects the entire environment because the pressure on the region increases and the magnetosphere shrinks sometimes four Earth's radii. This sudden compression causes earthquakes in specific plates. During the times of solar minima the pressure from the solar wind on the earth decreases, then the magnetosphere expands and earthquakes happen in a different pattern according to the geological feature on earth's surface less frequently. Solar driven events include coronal mass ejections (CME) and coronal holes, which are at a maximum during the descending phase of solar activity. The tectonic are important because there is heterogeneity in the crust and the tectonic stress depends on each region. The geo-effectiveness of solar wind from a coronal hole only depends on the position of the hole relative to the Earth and for the CMEs an additional factor is their velocity. The influence of these solar events could be detected from electromagnetic variations on the ground prior the earthquakes. The goal in this research was to show the solar events influenced the earthquakes and seismologic events following some special display and also how the Sun's activity played to make earthquakes increase. This paper discussed details of this mechanism, calculations and associated factors.

Decreasing Rate of M>=7 Earthquakes in the Northern Hemisphere Since 1900

“…Such research ideally would include suggestions and models about the physical mechanism driving the phenomena. Patterns of global seismicity were recognized in the past, and different explicative hypotheses were formulated (e.g., Bath, 1984a,b;Tsapanos and Liritzis, 1992;Liritzis et al, 1995;Sidorenkov, 2009;Tavares and Azevedo, 2011). However, their robustness seems to be undermined by the short period of observation or the lack of complete catalogs spanning at least a few centuries in a uniform way.…”

Sun-Moon-Earth Interactions, External Factors for Earthquakes

“…This indicates that 92% of giant earthquakes occur in ocean subduction zones. P = Nano-pascals, n = particles/cm 3 and, v = km/s, both n and v varies depending of the intensity of Solar Storms [1]. The dynamic pressure is much larger than the thermal pressure or magnetic pressure from solar wind.…”

“…The inclusion of the Moon in this paper serves to update our recent article [9] about the interaction between the Moon and Earth. The second part of this paper will examine the influence of the Sun on the Earth with a wider view than in [1]. Our first conclusions for the gravitational force show the highest percentage of geohazard events took place when the Sun-Moon-Earth were aligned at 180 0 with the Moon facing the Sun on its dayside magnetosphere (New or 1 st Quarter), [9].…”

“…Any effects from the solar wind when coming through the atmosphere are also changed by the interactions of streams with the plasma jet in the higher atmosphere, and winds in the lower atmosphere. Our previous paper supposed that if the magnetosphere were quiet, the locations under pressure from high-speed winds would eventually reach a rupture point in the crust and possibly trigger earthquakes depending on the tectonics of each plate [1]. At that time, the authors worked with different tectonic plates worldwide.…”

“…In Influences of Solar Cycles on Earthquakes [1], Tavares and Azevedo explained a possible SunEarth influence through sun storms, which increase the solar wind speed and the flux of ionized particles. Most particles are reflected by the magnetopause and bow shock, but some enter the magnetosphere near the poles, creating the auroras.…”