GEOLOGY

Detailed explanation-1: -Whereas pahoehoe lava flows smoothly like water or molasses, a’a lava tumbles in the form of small rocks with very jagged sharp edges.

Detailed explanation-2: -’A’ā lava flows have irregular rough surfaces made of jagged, spiny and rough clasts of lava called clinkers. These lavas have surfaces that are either too viscous or are flowing too rapidly to flow plasticly like pāhoehoe. Instead they are ripped apart by shear strain forming a breccia at the top of the flow.

Detailed explanation-3: -’A’ā (pronounced “ah-ah") is a Hawaiian term for lava flows that have a rough rubbly surface composed of broken lava blocks called clinkers. The incredibly spiny surface of a solidified ‘A’ā flow makes walking very difficult and slow.

Detailed explanation-4: -Pahoehoe is lava that in solidified form is characterized by a smooth, billowy, or ropy surface, while aa is lava that has a rough, jagged, spiny, and generally clinkery surface. In thick aa flows, the rubbly surface of loose clinkers and blocks hides a massive, relatively dense interior.

Detailed explanation-5: -Aa forms when lava flows rapidly. Under these circumstances, there is rapid heat loss and a resulting increase in viscosity. When the solid surface crust is torn by differential flow, the underlying lava is unable to move sufficiently rapidly to heal the tear.