Gravity Variations Over Earth Much Bigger Than Previously Thought

Sep. 4, 2013 — A joint Australian-German research team led by Curtin University’s Dr Christian Hirt has created the highest-resolution maps of Earth’s gravity field to date — showing gravitational variations up to 40 per cent larger than previously assumed.

Using detailed topographic information obtained from the US Space Shuttle, a specialist team including Associate Professor Michael Kuhn, Dr Sten Claessens and Moritz Rexer from Curtin’s Western Australian Centre for Geodesy and Professor Roland Pail and Thomas Fecher from Technical University Munich improved the resolution of previous global gravity field maps by a factor of 40.

“This is a world-first effort to portray the gravity field for all countries of our planet with unseen detail,” Dr Hirt said.

Earth’s gravity field gallery

Riff-in-Thyme said:

Gravity Variations Over Earth Much Bigger Than Previously Thought

Sep. 4, 2013 — A joint Australian-German research team led by Curtin University’s Dr Christian Hirt has created the highest-resolution maps of Earth’s gravity field to date — showing gravitational variations up to 40 per cent larger than previously assumed.

Assumed? Surely it was measured rather than assumed.

Such a large error on previous measurements seems extraordinary to me.

I hope dv will comment.

Riff-in-Thyme said:

Earth’s gravity field gallery

That link was definitely worth a look. I was startled a few months ago (while looking through an old almanac) to find how big the gravity variations on the Earth’s surface really are. In Australia you weigh noticeably less than in England for instance, the average difference is of the order 0.1%, almost large enough to detect on a standard set of bathroom scales.

Riff-in-Thyme said:

Earth’s gravity field gallery

That link was definitely worth a look. I was startled a few months ago (while looking through an old almanac) to find how big the gravity variations on the Earth’s surface really are. In Australia you weigh noticeably less than in England for instance, the average difference is of the order 0.1%, almost large enough to detect on a standard set of bathroom scales.

Looking at the data I see that if you want to lost weight instantly, go to Perth.

“GGMplus is a joint gravity field initiative of Curtin University and Technical University Munich. GGMplus is the first model of Earth’s gravity field to reach local resolution with near-global coverage. GGMplus is constructed as a composite of GRACE and GOCE satellite gravity, EGM2008 and short-scale topographic gravity effects.”

For video introduction, see GGMplus

The Curtin University website also has gravity maps of the Moon and Mars.