Gravity anomalies layer — the static shape of Earth's gravity field: where gravity is stronger or weaker than the smooth reference ellipsoid, in milligals (mGal; 1 mGal ≈ a millionth of surface gravity). It comes from the Sandwell & Smith global gravity grid (Scripps Institution of Oceanography, UC San Diego), built from satellite altimetry over the oceans and the EGM2008 model over land, native resolution 1 arc-minute, shown here at 0.25°. The satellite-altimetry grid stops at ±80° latitude, so the polar caps show as dark no-data.
Mass change layer (GRACE) — how Earth's mass distribution shifts month to month, from the GRACE and GRACE-FO satellite missions (CSR RL0603 mascon solution, University of Texas at Austin). Values are centimeters of equivalent water height, relative to the 2004–2009 average: blue = mass gained, red = mass lost. Watch Greenland and Antarctica bleed red across 2002 → 2026 — that's ice leaving the land and raising the sea. Effective resolution is a few hundred km, so coastlines are fuzzy.
Is it live? Not minute-to-minute — no gravity data is. GRACE-FO measures continuously, but each monthly field takes weeks to process and publish. This app carries the full record, April 2002 through the latest available month, and the gravity layer is the current published composite.
Sources: Sandwell et al., Scripps/UCSD (topex.ucsd.edu); CSR GRACE/GRACE-FO RL0603 mascons (download.csr.utexas.edu); coastlines: Natural Earth. Colors saturate at the legend limits; the tap/hover readout always shows the true stored value.