Qiuyun+Liu+Yiqi+Li+Juntong+Zou+Fan+Yang+Xiang+Zhu

【Abstract】The fortnightly periodicity and other patterns of the seismic activities on the earth suggest that lunar and solar pulls are fundamental factors underlying earthquakes. The time lag in the decelerations of large mass relative to small mass after solar and lunar accelerations builds up strain which eventually results in earthquakes. Similarly， the sunspot cycle of about 11 years corresponds to the Jupiters revolution to the perihelion. The butterfly phenomena of sunspot corroborate such a scenario. Therefore short sunspot cycles can be harnessed to search for earth-like planets.

【Key words】Starspot periodicity； extrasolar planets； earthquakes

The small and near constant annual scale of continental drift suggests that minor in magnitude and steady forces are at play. The fortnightly periodicity of the seismic activities suggests that lunar pull is a key factor in triggering earthquakes1，2. Fortnightly and perhaps other patterns for large magnitude earthquakes were not apparent due to the modest slopes where the Mega-quakes took place， when the threshold of strain was reached over a wide region of similar slopes via smaller cumulative accelerations by lunar and solar pulls. The wide region off the northeast coast of Japan also acted as a break of the whole Japanese archipelago before the 2011 mega quake， where steep slopes with large potential energies are present off the southeastern coast as water is much lighter than rocks. The inertia of an object is determined by its mass and speed， which explains the lack of large earthquakes in the arctic and Antarctic3 where tangential speed of self-rotation is low. The time lag in the decelerations of large mass relative to small mass after solar and lunar accelerations in the process of earths self-rotation builds up strain which eventually results in earthquakes. In a similar fashion， the sun experiences a sunspot cycle of about 11 years4， which corresponds to the Jupiters revolution to the perihelion as its orbit is an ellipse. Jupiter is circling around the equatorial plane of the sun with a very small inclination angle.

The self-rotation of the sun and the presence of the equator are manifested in the gravitational field of the solar reference system. The drift of masses in the fastest moving equator of the sun is enhanced by the change of gravitational pulls from the planets. The effects of increased gravitational pull are most pronounced on the accelerations and decelerations of fast moving masses with large inertia， which then exposes regions in the sun during the approach of Jupiter to perihelion. There are many types of different sunspot periodicities5，6， which can be explained by the interplay of gravitational pull of the planets in the solar system. The butterfly plot refers to the migration pattern of sunspots towards the equator over time4. The equator related and planet cycle related sunspot phenomena are the interactions of the solar system. The phenomena of sunspots have also been observed in other stars7-9. The starspot periodicity and magnitude can thus be harnessed to search for earth-like planets in outer space.

ACKNOWLEDGMENTS

This work was supported by the Guangdong Natural Science Foundation （S2011010004264）， Guangdong Science and Technology Program （No. 2008B020100001）， Open Fund of MOE Key Laboratory of Aquatic Product Safety， Foreign Expert Program at Sun Yat-sen University， Open Fund of Laboratory （201501024） and 2016 Key Project Budget at Sun Yat-sen University， The National Natural Science Foundation of China （21601209 and J1310025）， The National Key Technology R&D Program （2012BAD17B03）， The National Key Technology R&D Program （2011BAD13B10）， and the Public Welfare and Competence Program of Guangdong Province （2016B020204001）. We thank suggestions and discussions from Ziwei Ye， Zhenxiao Zhuang， Cui Yang， Xiren Nuertai， Weiguo Cao， Jing Li， Yuchuan Wang， and Xiaoxuan Wu. Manuscript proofreading by Yan Shi is appreciated.

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