A shatter ring forms and grows on the Kamokuna lava
delta. This video shows repeated uplift and subsidence of the delta surface by the lava supply under the surface. This process creates a large round rubble pile, called a shatter ring. The uplift is caused by extra lava accumulating in the tube, either from more volume coming in, or from a blockage that does not allow lava to pass through easily. This extra lava needs space, and lifts the rock above it to make that space. If the rock breaks, which often happens around the base at the flexure point, then lava can flow out of the tube and onto the surface, causing the uplift to reverse.