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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Japan earthquake speeds earth's rotation
From: Bill B
Date: 2011 Mar 15, 04:07 -0400
From: Bill B
Date: 2011 Mar 15, 04:07 -0400
On 3/14/11 1:38 PM, Lu Abel wrote: > The scenario is similar to that of a figure skater drawing her arms > inward during a spin to turn faster on the ice. The closer the mass > shift during an earthquake is to the equator, the more it will speed up > the spinning Earth. This analogy confuses me. If a figure skater draws his/her arms in (nearer to the axis of rotation), the rate of spin increases. OK. "The closer the mass shift during an earthquake is to the equator, the more it will speed up the spinning Earth." I am not clear, assuming the temblor does not solely move the island (in this case) closer to the axis of rotation) what affect a shift would have based on its relationship to the equator. From a layman's vantage point, a 100 mile move from a pole towards the equator would be greater shift relative to the axis than a move from 100 miles north or south of the equator to the equator. Finally, the post stated,"More impressive is that the entire main island of Japan (Honshu) moved eight feet to the east!" East is neither towards or away from the equator. So why the speed change in simple terms? Action and reaction? Bill B.