Unified Interior Regions

The level of the lava lake sometimes changes abruptly. These cycles of rise and fall, which amount to a vertical change of around 15 m (about 50 ft), are occasionally triggered by rockfalls. Here, a small collapse from the vent wall triggers degassing and a drop in the lava level.

As the spattering shown in the previous video intensifies, the walls of the vent heat even more, causing the cracking of the rocks through thermal expansion to speed up, creating the cacophony of popping noises apparent in this video.

Time-lapse movie showing lava erupting from vents on the floor of Pu‘u ‘Ō‘ō crater. Each frame is a composite of eight images comprising a panorama of the crater that is captured every five minutes. During daylight hours, the camera switches to an IR mode so that eruptive activity is easier to monitor. At night, the camera switches back to normal mode.

Another series of collapses occurred within Kīlauea's summit vent on the floor of Halema‘uma‘u before sunrise on February 15. This movie shows the first of the rockfalls and the resulting small explosive event.

Sounds of lava lake activity within Kilauea Volcano's summit vent inside Halema`uma`u Crater on the afternoon of February 14, 2011. The continuous "crashing wave" noise is the sound of churning lava as gases are released from the lake surface, which is in nearly constant motion. The discontinuous sharp "pops" occur when rocks falling from the vent wall hit the lava lake

Movie of lava flows in Pu‘u ‘Ō‘ō crater from February 6-8. Lava has been erupting sporadically from three vents within Pu‘u ‘Ō‘ō crater-a cone on the west side of the crater floor (foreground to left), a cone on the northeast side (center frame), and from an opening on the east crater wall (background).

Movie of the January 21 collapse and dusty plume captured by a Webcam located in the observation tower at the Hawaiian Volcano Observatory.

Movie of the January 17 collapse and explosive eruption captured by a Webcam located in the observation tower at the Hawaiian Volcano Observatory.

Movie of the January 17 collapse and explosive eruption captured by a Webcam located on the rim of Halema‘uma‘u directly above the erupting vent.

Side-by-side comparison of the northwest wall of Kīlauea Caldera on a clear day (left) and a day with thick vog (right). HVO observation tower and building can be seen near the center in each photo

Sulfur dioxide gas emissions from the crater of Pu‘u ‘Ō ‘ō on Kīlauea’s east rift zone and the vent within Halema‘uma‘u Crater at Kīlauea’s summit create volcanic pollution that affects the air quality of downwind communities.  Here, a USGS Hawaiian Volcano Observatory gas geochemist measures Pu‘u ‘Ō‘ō gas emissions using an instrument that detects gas compositions on the