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ESA's GOCE Satellite Provides Gravity Map of Earth
kaulike writes "The European Space Agency's GOCE satellite, launched in March 2009, has provided a spectacular, highly detailed map of our favorite gravity well. This map shows the normalized surface of the earth as defined by gravity, showing the relative altitude differences from the average for each surveyed point. The article provides the helpful metaphor that a ball resting on this surface would not roll anywhere, even though there would be visual slopes, as gravity is equalized across the globe. There is a fascinating deep area in the Indian ocean (-100M) and a high area near Iceland (+80M), proving conclusively that our world is not homogeneous in terms of density (or practically any other measure). Does anyone know whether these anomalies correspond to known geographic phenomena? Deposits of heavy metals perhaps, or hotspots where the mantle is thinner? I know little about geodetic stuff, but I'm curious about the reasons for wrinkles in the data set."
Gravity map? Heavy, man!
That is all.
No, but they do correspond to the location of the stargates.
---- Booth was a patriot ----
If you look at the map, a lot of the high-gravity areas tend to appear near highly volcanic areas like the ring of fire (and, as the reader pointed out, Iceland). I wonder if this has something to do with more magma being closer to the surface in those areas...or something similar?
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It's worth taking a read of the satellite itself. Apparently, the accelerometers themselves (3 pairs of them) are mounted to within one picometre (that is micro-micro-metre). Gravity measurements are to within 10^-13 G. All pushed ahead by a cool xenon ion engine :)
That's some serious engineering precision. A bit more than your average accelerometer in your iPhone.
There's a bit more on how it works in this article.
Of course, the raw data looks a lots uglier than the beautiful image of the final result, but if the research is for climate change, then manipulating raw data is what they do best ;)