Photo and Video Chronology - Kīlauea - September 8, 2017

Release Date:

Collapses common during significant drops in summit lava lake

 

Collapses common during significant drops in summit lava lake...

On September 8, at 6:06 p.m. HST, much of the large ledge that had built up on the south side of the summit vent within Halema‘uma‘u collapsed. The top two images, captured by HVO's K2 and HT web cameras, show the summit vent before the collapse. A yellow arrow points to the ledge, which was formed by layers of lava stacking up during repeated high lake levels. The lower webcam images were captured minutes after the collapse. In the thermal images, note the difference in the lava lake surface before and after the collapse. K2cam shows the view from HVO and Jaggar Museum; HTcam is a thermal camera that looks down on the lava lake from the rim of Halema‘uma‘u.

(Public domain.)

HVO K2cam image at the time of the 6:06 p.m. collapse on Sept. 8. ...

HVO K2cam image at the time of the 6:06 p.m. collapse on Sept. 8. Interestingly, this collapse did not generate a large explosion—only a small, brownish plume was observed during and immediately after the rocky ledge fell into the lava lake. The next day, HVO geologists noted a dusting of ash on the Halema‘uma‘u crater rim, but found no spatter fragments like those that have been hurled to the crater rim during past large explosions. At the time of the Sept. 8 collapse, the lava lake level was about 53.5 m (176 ft) below the vent rim, too deep to be visible from HVO. Collapses are more common when the lava lake level drops significantly, because support is removed from the crater walls.

(Public domain.)