Photo and Video Chronology - Kīlauea - March 29, 2002

By Kīlauea March 29, 2002

Spatter structures, and crustal overturning in Episode 55 crater

photo of lava — Two different structures built of spatter. Remarkable, 11.8-meters-high spire at one of the hornitos at the 2300-foot elevation, between Pu`u `O`o and the rootless shields. Note person for scale.

Crustal overturning in Episode 55 crater

Lava began to fill the Episode 55 crater, just west of Pu`u `O`o, on March 27-28. A pond formed, with a floating crust. Gas bubbles rising from the lava in the pond are trapped by the crust. A density inversion results; lighter, bubbly lava underlies denser crust. Eventually a crack forms in the crust. The lighter lava gushes to the surface and overrides the crust. A slab of the crust breaks off, turns on end, and dives into the pond like a sinking ship. This process is called crustal overturning. An overturning event often sweeps across the surface of a pond in a few tens of seconds. These photos show one such event, moving toward the camera.