Re: Gravity mapping and the Earth

[Judith Rosen <***>]

Hi John K.

Thanks John! I'll check it out.

One of the intriguing aspects of the gravity measuring stuff at the link Tim
posted was the discussion on how the tectonic plate activity impacts
gravity. There was also discussion of how the density of various underlying
materials would impact the measurements of gravity. According to the global
maps that are the latest produced from the GRACE satellite data, there are
still areas in the ocean that have "more gravity" than some of the mountain
ranges in the northeastern US. I'm fascinated!

I checked to see if the Bermuda Triangle had some weird gravitational stuff
going on, but it's actually got very low gravity and it is not unique in
that respect. Ah well.....

I wonder what effect reservoirs of water under the surface of land have, if
any, on the "gravity" of the area over the reservoir? Perhaps this effect
might explain "dowsing"?

Judith

----- Original Message -----
From: "John Kineman" <***>
To: <***>
Sent: Monday, November 08, 2004 11:49 AM
Subject: Re: [ROSEN] Gravity mapping and the Earth


> Judith,
>
> We have a gravity data program here at NGDC. Take a look at:
> http://www.ngdc.noaa.gov/seg/gravity/welcome.shtml
>
> One of the things you can do with gravity data is map the relief of the
> Earth, because mountains add mass and thus increase the local gravity.
> I used to be the gravity officer in the '70s. on the NOAA Ship
> Oceanographer - you can actually measure gravity at sea using very
> sophisticated equipment.
>
> JK