How Lava Flows
Two Hawaiin words: pahoehoe and aa
Pahoehoe (Pa-hoy-hoy) - smooth or ropy
lava. Cooler lava hardens on the surface;
hotter, more fluid lava runs under it often leaving
caves or tubes behind.
Aa (ah-ah) - rough, jagged, lava, The molten
lava is much less fluid and usually moves
slower. A crust never hardens on the surface,
but chunks of cooler rock tumble along the
top and sides instead. Aa can be impassable.
