# Forward modeling with 2D polygons (fatiando.gravmag.talwani)¶

Calculate the gravitational attraction of a 2D body with polygonal vertical cross-section using the formula of Talwani et al. (1959)

Use the Polygon object to create polygons.

Warning

the vertices must be given clockwise! If not, the result will have an inverted sign.

Components

References

Talwani, M., J. L. Worzel, and M. Landisman (1959), Rapid Gravity Computations for Two-Dimensional Bodies with Application to the Mendocino Submarine Fracture Zone, J. Geophys. Res., 64(1), 49-59, doi:10.1029/JZ064i001p00049.

fatiando.gravmag.talwani.gz(xp, zp, polygons, dens=None)[source]

Calculates the $$g_z$$ gravity acceleration component.

Note

The coordinate system of the input parameters is z -> DOWN.

Note

All input values in SI units(!) and output in mGal!

Parameters:

• xp, zp
: arrays

The x and z coordinates of the computation points.

• polygons
: list of Polygon

The density model used. Polygons must have the property 'density'. Polygons that don’t have this property will be ignored in the computations. Elements of polygons that are None will also be ignored.

• dens
: float or None

If not None, will use this value instead of the 'density' property of the polygons. Use this, e.g., for sensitivity matrix building.

Note

The y coordinate of the polygons is used as z!

Returns:

• gz
: array

The $$g_z$$ component calculated on the computation points