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Name: John G.
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Question:
Would a large submarine, whilst travelling below the sea surface, affect the Earth's geoid, enabling an extremely sensitive satellite based gradiometer, to detect the anomaly caused by a moving submarine, in comparison to a high-resolution reference map of the geoid? The submarine would most probably be at neutral buoyancy, with depth adjusted via its control surfaces. However, whilst the overall structure of the submarine would be neutral in buoyancy, there would be a large internal volume where the water will be 100% displaced by air, and thus have almost nil mass in comparison to the water surrounding it. Rune Floberghagen, Esa's GOCE (Gravity field and steady-state Ocean Circulation Explorer satellite) mission manager explained the sensitivity of GOCE as follows: "Imagine a snowflake, which has a fraction of a gram, slowly falling down on to the deck of a super tanker. The acceleration that the super tanker experiences from that snowflake is comparable to the sensitivity of our instrument"



Replies:
While not wish to sound "conspiratorial", military research funded by various nations, by no means is the U.S.A. is lagging, is often years ahead of civilian or commercial applications. The "stealth" bomber is just one example that could be cited. Given the precision of "atomic" clocks and GPS systems, it would not be very surprising if extremely small variations in gravitational and/or magnetic disturbances could be monitored and tracked.

Vince Calder



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