Small explosion at Halemau'uma'u crater on 19, March, 2008
On March 19, 2008, a small explosion occurred at Halema'uma'u Crater at the summit of Kīlauea Volcano. This is the first explosive event at the summit of Kilauea after almost a century. Below is the fully detailed report provided by HVO:
No lava was erupted as part of the explosion, suggesting that the activity was driven by hydrothermal or gas sources. In addition to damaging the overlook, explosive debris covers the trail to the overlook, the Halema'uma'u parking area, and the portion of Crater Rim Drive adjacent to the parking area. On Crater Rim Drive the debris was up to 2 centimeters in size, with the size and thickness of debris increasing toward the overlook. The largest observed block ejected during the explosion was about 1 cubic meter (35 cubic feet) and must have been propelled from the vent located more than 70 m (230 feet) below the crater rim. Small impact craters from 30 cm (1 foot) blocks are abundant in the Halema'uma'u overlook area. Rock debris also extends halfway across the floor of Halema'uma'u Crater. The debris is composed of rock fragments that were derived from the walls of Halema'uma'u Crater. No fresh lava was observed on the floor of Halema'uma'u or in the ejected debris.
At 2:55 am, the Hawaiian Volcano Observatory recorded a series of seismicevents that may have been shallow, high-frequency earthquakes or minor explosions. The main explosion at 2:58 was associated with long period seismicity. Low frequency sound waves were also detected by the University of Hawai`i infrasound laboratory, operated by Dr. Milton Garces. These signals have persisted through this morning indicating continuing energetic release of gas from the vent in Halema'uma'u Crater.
The explosion produced a small crater along the east wall of Halema'uma'u that is about 20-30 meters (65-100 feet) in diameter. The crater occupies the area in which incandescence had been observed during the previous week. Sulfur dioxide emissions from the new explosion crater are still elevated, and sounds of rock breaking are frequent. This is the first explosion in Halema`uma`u crater since 1924 and the first eruption of any kind in Kīlauea caldera since September 1982. Future explosive activity is possible and the Hawaiian Volcano Observatory continues to monitor the activity. Photos, text updates, a new Halema`uma`u crater webcam, and details about the Kilauea 1924 explosive eruption can be found at the HVO website: hvo.wr.usgs.gov. >