Aa-aa lava flows
Volcano Learning zone > Volcano Glossary
Aa aa lava is a basaltic lava flow found where basalt lavas erupt, it is a slow moving lava flow which is rough and blocky. AA-aa is an hawaiian word ,traditionally imitating the cry of people walking on the lava. It is at a lower temperaure than its counterpart Pahoehoe at around 1000C. The lower temperature means that it is more viscous and flows as a blocky lava flow consisting of blocks called clinker. It moves slowly and creeps forward the top of the flow falling over the front face. The core of the flow is a paste like thick lava. Once cooled the surface is very rough and treachorous to walk on.