3D Gravity Forward Modeller

01 Coordinates and reference surface

Horizontal distances are in km; depth is positive downward from the surface

Coordinate reference Body-centre latitude (°) Body-centre longitude (°) Body-centre depth (km) Grid-centre latitude (°) Grid-centre longitude (°) Observation height (m) Grid extent X × Y (km)

02 Coupled modelling workspace

Sculpt the body on the left · inspect the gravity response on the right

3D density bodyDrag boundary points · rotate empty space · wheel to zoom

X: Easting · Y: Northing · Z: depth

Click to select · drag to sculpt

Live gravity response Δg_zUpdates automatically after geometry editing

Preparing calculation

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Minimum—

Maximum—

Max–min—

03 Physical properties and calculation

Automatic live recalculation after input and geometry changes

Density contrast Δρ+350 kg/m³

Calculation resolution0.18 km

Editing section—

Selected-section size100%

Preset geometry10 sections · 24 points per section

Apply topographic surfaceOFF

E width 100% N width 100% Height 100%

Rectangular-prism count—Including 2 × 2 boundary subcells

Calculation time—For the current browser

Centre-point convergence difference—Current grid versus 1.6× spacing

Volume—Sum of rectangular-prism volumes

Geometry sculpting and numerical calculation

Surface points within the brush radius are deformed with distance weighting for pulling, inflation, deflation, and smoothing. Selected boundary points and cross-sections can be added or deleted. Cross-sections with different point counts are periodically resampled before voxelization. After editing, rebuild the voxels to evaluate the vertical gravity component of each rectangular prism analytically.

Terrain data and scope

When terrain is enabled, AWS Open Data Terrain Tiles are loaded and gravity is calculated at the terrain elevation of each observation-grid point. Source data and effective spatial resolution vary by region. The calculation represents a homogeneous density-contrast body in a local WGS84 tangent plane; it does not include the reference gravity field or corrections applied to observed gravity data.