Gravity is different in every part of the earth

[KMc]

This is an important factor in metrology. For example, if you calibrate a scale on one part of the earth and send it to another, the calibration would be off if you don't account for the variance in gravity.

 

[dennilfloss]

Do a google image search on "bouguer gravity anomaly" and "free air gravity anomaly" and find a map of gravity for your fair town.

In one of my geophysics classes one student project was to determine if gravity anomalies would have a measurable impact on ski jumping results for events held in different parts of the world. The answer was "yes", gravity could explain up to a centimeter or so of additional/less distance in ski jumping.

Also, gravimeters can detect differences in gravity within a room based on whether you set them on a table or on the floor.

For one lab, we had to measure gravity at every floor of the building when I took geophysics during the late 70s. There was a nice gravity delta measured when you went up/down just one floor.

 

[dennilfloss]

BTW, gravity maps are a useful prospecting tool particularly when combined with geomagnetic maps.

 

[IronWing]

In what way can this be really useful? We already have lots of projects that are already proven useful that don't get enough funding.

Useful for exploration for oil, metals, diamonds, mapping aquifer deletion.

 

[AyashiKaibutsu]

g*m1*m2/r^2

This... really did we need a thread about this...

Next we need a thread zomg earth is an oblate spheroid! to round things off.

 

[SKORPI0]

Goce satellite views Earth's gravity in high definition

1. Earth is a slightly flattened sphere - it is ellipsoidal in shape
2. Goce senses tiny variations in the pull of gravity over Earth
3. The data is used to construct an idealised surface, or geoid
4. It traces gravity of equal 'potential'; balls won't roll on its 'slopes'
5. It is the shape the oceans would take without winds and currents
6. So, comparing sea level and geoid data reveals ocean behaviour
7. Gravity changes can betray magma movements under volcanoes
8. A precise geoid underpins a universal height system for the world
9. Gravity data can also reveal how much mass is lost by ice sheets

 

[Malak]

Useful for exploration for oil, metals, diamonds, mapping aquifer deletion.

Discovering diamonds is no longer necessary now that we can make them synthetically. How does exploring the slight variations in gravity over large areas help with any of the rest?

 

[BoomerD]

FINALLY! Something on which I can blame my fatness!

I'm not fat...my bathroom scales were made in a low-gravity area...and I live in a high gravity area.

Genius!

 

[IronWing]

Discovering diamonds is no longer necessary now that we can make them synthetically. How does exploring the slight variations in gravity over large areas help with any of the rest?

There is still a huge market for natural diamonds. Just a matter of taste there.

We need the broad field data in order to lay the background for determining what is an anomaly and what isn't when taking a closer look with ground based and air borne instruments. The real question to my mind is "Does this space craft yield us additional or a different kind of information that could not have been obtained at lower cost using ground based or air borne instruments?"

 

[JTsyo]

For one lab, we had to measure gravity at every floor of the building when I took geophysics during the late 70s. There was a nice gravity delta measured when you went up/down just one floor.

hmm that would mean that there's no terminal velocity since your weight would increase as you fell, taking more drag to slow you. Though the air does get thicker and drag is v^2, guess that would kill velocity increases pretty quick.