# How to calculate the mantle Bouguer anomaly (MBA) and residual mantle Bouguer anomaly (RMBA)

**URL:** <https://forum.generic-mapping-tools.org/t/how-to-calculate-the-mantle-bouguer-anomaly-mba-and-residual-mantle-bouguer-anomaly-rmba/131>\
**Category:** Q&A\
**Created:** [December 5, 2019, 1:03pm UTC](https://forum.generic-mapping-tools.org/t/how-to-calculate-the-mantle-bouguer-anomaly-mba-and-residual-mantle-bouguer-anomaly-rmba/131 "2019-12-05T13:03:30Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ghomsi123](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/ghomsi123/32/79_2.png) [@ghomsi123](https://forum.generic-mapping-tools.org/u/ghomsi123)\
**Post date:** [December 5, 2019, 1:03pm UTC](https://forum.generic-mapping-tools.org/t/how-to-calculate-the-mantle-bouguer-anomaly-mba-and-residual-mantle-bouguer-anomaly-rmba/131/1 "2019-12-05T13:03:30Z")

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Hi,  
Currently, I am using an ASCII grid and I would like to calculate the **MBA** and **RMBA**.  
Since I am working on the land (continent), it is necessary to use the **bathymetry** to compute the effect of the water or should I use the topography? According to that what’s the computing methods?

Thanks!!!

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**Author:** ![John](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/john/32/40_2.png) [@John](https://forum.generic-mapping-tools.org/u/John)\
**Post date:** [November 19, 2023, 8:11am UTC](https://forum.generic-mapping-tools.org/t/how-to-calculate-the-mantle-bouguer-anomaly-mba-and-residual-mantle-bouguer-anomaly-rmba/131/2 "2023-11-19T08:11:32Z")

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please use topography alone. Since your work is restricted to the continent.

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**Author:** ![EvanPi](https://avatars.discourse-cdn.com/v4/letter/e/e47774/32.png) [@EvanPi](https://forum.generic-mapping-tools.org/u/EvanPi)\
**Post date:** [August 7, 2026, 7:10pm UTC](https://forum.generic-mapping-tools.org/t/how-to-calculate-the-mantle-bouguer-anomaly-mba-and-residual-mantle-bouguer-anomaly-rmba/131/3 "2026-08-07T19:10:28Z")

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Does anybody have an example script for full shipboard gravity to RMBA?