Book 12, Question 6
Why Does Aa Lava Look Spiky?
Aa lava is thick, sticky lava that breaks into rough, sharp chunks as it creeps forward. It is spiky because it cracks while it is still moving, which makes the ground very rough. Lava is dangerous, so stay far away and follow grown-ups and local warnings.
More fun facts
- Hawaiian words name two main kinds of lava: pahoehoe and aa.
- Pahoehoe has a smooth, ropy surface.
- Aa lava is rough and spiny, made of jagged blocks called clinker.
- Young lava fields of both types make dramatic landscapes of dark volcanic rock.
- Squeeze ups form when thick lava oozes through a crack in a flow's solid crust.
Sources: National Park Service, U.S. Geological Survey, National Park Service
Questions kids ask
What is clinker?
Rough, jagged, spiny blocks of lava that cover an aa flow.