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Authors: D. Fargion

Date: Thu, 30 Dec 2004

Abstract: The present gravitational wave detectors are reaching lowest metric deviation fields able to detect galactic and extra-galactic gravitational waves, related to Supernova explosions up to Virgo cluster. The same gravitational wave detector are nevertheless almost able to reveal near field gravitational perturbations due to fast huge mass displacements as the ones occurring during largest Earth-Quake or Tsunami as the last on 26nd December 2004 in Asiatic area. The prompt gravitational near field deformation by the Tsunami may reach the LIGO threshold sensitivity, but not frequency band, and LISA within 3000 km distances. Their eventual discover (in future on-line detector arrays) may offer the most rapid warning alarm system on earth. Nevertheless the later continental mass rearrangement and their gravitational field assessment on Earth must induce, for Richter Magnitude 9 Tsunami, a different terrestrial inertia momentum and a different rotation axis, as well as a detectable shrinking of the Earth radius of nearly R =3.4 micron. and a consequent faster Earth spinning by a ratio Delta w/w_= -1.08 10ˆ{-12} and a year duration shortening of the order of Delta {t_{year}}= - 34 micron s; if all the energy released is absorbed by the terrestrial rotation energy the opposite would occur, Delta w/w = 2.59 10ˆ{-10}, with a longer year lenght: Delta t {year} = 8.17 10ˆ{-3} s; because the terrestrial gravitational energy is nearly 480 times its rotational one, the mutual energy exchange may in general leads to a spin up or a spin down of the day lenght within Delta t= 22.4 10ˆ{-6} s. well within detection.

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