HomeVolcanologyPāhoehoe vs ʻAʻā Lava

🌋 Pāhoehoe vs ʻAʻā Lava

Drag viscosity, shear-rate and cooling sliders to watch a real basaltic lava flow transition from smooth ropy pāhoehoe into rubbly, clinkery ʻaʻā — a real, one-way volcanological process.

Volcanology2DModerate60 FPS🌍 Earth
pahoehoe-vs-aa ↗ Open standalone

What It Demonstrates

Both textures are the same molten basalt; the difference is purely mechanical. Low viscosity, low shear rate and hot, still-fluid lava keeps its thin glassy skin intact — dragging it into the smooth, ropy folds of pāhoehoe. Raise viscosity, shear or cooling/crystallinity and the same skin can no longer stretch: it shatters into the jagged, clinkery rubble of ʻaʻā, riding on a still-molten core. The mesh here is coloured by simulated surface temperature and its geometry is procedurally deformed from vent (near) to toe (far downslope).

How to Use

Drag Viscosity, Shear rate and Cooling / crystallinity to change how far downslope the flow stays smooth before it roughens. Higher values move the transition point closer to the vent. The presets jump to typical Hawaiian pāhoehoe or typical ʻaʻā conditions.

Did You Know?

Pāhoehoe (pronounced pa-HOH-ee-HOH-ee) and ʻaʻā (AH-ah) are Hawaiian words adopted worldwide by volcanologists — the only Hawaiian loanwords in international scientific vocabulary. A single Hawaiian flow can start as pāhoehoe near the vent and turn to ʻaʻā a few hundred metres downhill as it cools, a transformation first formally described by geologists studying Kīlauea.

⚙ Under the hood

Drag viscosity, shear-rate and cooling sliders to watch a basaltic lava flow transition in real time from smooth, ropy pāhoehoe into rough, clinkery ʻaʻā.

lavavolcanologybasaltviscositygeologylava-flow

2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install

What did you find?

Add reproduction steps (optional)