harmonica

name	harmonica
description	Gravity and magnetic data processing and forward modelling using Fatiando a Terra. Use when Claude needs to: (1) Compute gravity forward models (point masses, prisms, tesseroids), (2) Apply terrain/Bouguer corrections, (3) Grid scattered potential field data with equivalent sources, (4) Perform upward/downward continuation, (5) Calculate magnetic anomalies from magnetized bodies, (6) Apply derivative filters (gradients, tilt angle), (7) Process regional or local gravity surveys.
version	1.0.0
author	Geoscience Skills
license	MIT
tags	["Gravity","Magnetics","Potential Fields","Forward Modelling","Fatiando"]
dependencies	["harmonica>=0.6.0","numpy","verde"]
complements	["verde","pyvista"]
workflow_role	analysis

Harmonica - Gravity and Magnetics

Quick Reference

import harmonica as hm
import numpy as np

# Forward model - prism gravity
prism = [-500, 500, -500, 500, -2000, -500]  # (west, east, south, north, bottom, top)
gravity = hm.prism_gravity(coordinates, prism, density=500, field='g_z')

# Terrain correction
layer = hm.prism_layer((easting, northing), surface=topo, reference=0,
                        properties={'density': 2670})
terrain_effect = layer.gravity(coordinates, field='g_z')

# Equivalent source gridding
eqs = hm.EquivalentSources(depth=10000, damping=10)
eqs.fit(coordinates, gravity_data)
grid = eqs.grid(spacing=5000, data_names=['gravity'])

# Upward continuation (requires gridded xarray)
upward = hm.upward_continuation(gravity_grid, height_displacement=1000)

Key Functions

Function	Purpose
point_gravity	Gravity from point masses
prism_gravity	Gravity from rectangular prisms
tesseroid_gravity	Gravity from spherical prisms (regional/global)
prism_magnetic	Magnetic anomaly from prisms
prism_layer	Create layer of prisms from topography
EquivalentSources	Grid scattered data with equivalent sources
upward_continuation