Lengthening of Day Curve Could Contain the Precusors of Earth-quakes and Impending Volcanic Eruptions

Abstract

Bijay Kumar Sharma

Study of Length of Day between 1890 to 2015 revealed that decrease in spin rate of Earth led to significant enhancement of Seismic Activity (SA) and visa-versa. Lengthening of Day powers the plate tectonic movement and SA which in turn leads to Earth-quakes and sudden volcanic eruptions. Earth’s rotation rate variation (LOD curve) is a function of geodynamical processes (Moon’s tidal drag on Earth) and seismic activities. Earth is tectonically asymmetric, tectonic equator is tilted about 30° with respect to the geographic equator and there is a global westerly drift of the lithosphere. Earth’s rotation change is important force source of Tectonic movements of Earth’s crust. 1% of energy released by de-spinning Earth is enough for Earth-quakes and sudden Volcanic eruptions. Earth’s rotation rate variability can release 10^21Joules enough for triggering tectonic movements which in-turn may result in major Earth-quakes or sudden Volcanic eruptions. Earth’s figure is subject to continuous pulsation. Long term observations of variation in Earth’s rotation reveals enhancement in spin rate of Earth in Summer and significant decrease in Winter. The spin rate is directly related to the ellipsoidal shape of Earth. Because of high spin rate in Summer results in an enhanced ellipsoidal shape resulting in large surface area of the continents and a relaxed condition of tectonic Earth plates which implies less seismic activity. Just the opposite happens in Winter. In Winter there is low spin rate resulting in a spheroid shape of Earth which results in contracted surface area of the continents hence tighter packing of tectonic Earth plates resulting in higher seismic activities resulting in large Earthquakes and sudden volcanic eruptions. The Author has done the theoretical formulation of LOD curve for last 1.2Gy and this can be extended in future. If this is subtracted from the observed LOD curve the precursors of Earthquakes and sudden Volcanic eruptions are obtained. Thus Observed LOD curve will act as Early Warning and Forecasting System of Earthquakes and sudden volcanic eruptions.

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