xAa : Hawaiian name for a type of lava flow with a surface that is broken into rough angular fragments which develop during cooling and loss of gas from pahoehoe flows.
In the spring of 2010, the eruption of a volcano called Eyjafjallajökull in Iceland cancelled many flights in Europe. Eyjafjallajökull is a glaciovolcano, which means it's a volcano that is covered by...Read more