μGal
microgal
Accelerationexact by definition
The microgal is 10⁻⁸ m/s², a billionth of Earth's gravity to within an order of magnitude. It is the resolution of a modern absolute gravimeter, and it is the level at which groundwater storage changes, magma movement and post-glacial rebound become directly measurable as a change in weight.
| 1 μGal | 1.0000000e-08 m/s² |
Where the unit came from
A microgal corresponds to about 3 mm of elevation change in the free-air gradient, which is why repeat absolute gravity measurements at a fixed pier can track vertical land motion without any satellite involved.
Solvers that use acceleration