# Photo and Video Chronology - Kīlauea - March 29, 2002

Release Date:

Spatter structures, and crustal overturning in Episode 55 crater

Two different structures built of spatter. Remarkable, 11.8-meters-high spire at one of the hornitos at the 2300-foot elevation, between Puu Oo and the rootless shields. Note person for scale.

(Credit: , . Public domain.)

Two flows spilling from January 02 vent, the middle of three spatter cones on the floor of Puu Oo's crater. This cone is 9.3 meters high. Shiny crust is fresh and hot.

(Credit: , . Public domain.)

### Crustal overturning in Episode 55 crater

Lava began to fill the Episode 55 crater, just west of Puu 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.

The overturning has just started. The red line is the advancing front. Lava behind the front is crusting over and clearly hotter than the older crust nearer the camera.

(Credit: , . Public domain.)

The overturning is advancing across the long dimension of the 85-90-meters-long, 25-30-meters-wide crater.

(Credit: , . Public domain.)

Note a bit more fume in the crater. The rapid release of trapped gas as the crust overturns contributes to the fume.

(Credit: , . Public domain.)

In this view, the crust nearest the camera has just overturned, and the fresh lava has not yet developed new crust.

(Credit: , . Public domain.)

The crust has now been completely renewed by the overturning event. The radiant heat from such overturning is great--witness the observer protecting his face.

(Credit: , . Public domain.)