A small explosion occurred at 12:55 a.m. on May 20 in Halema‘uma‘u...
Detailed Description
A small explosion occurred at 12:55 a.m. HST on May 20 in Halema‘uma‘u at Kīlauea Volcano's summit. It produced an ash plume that reached about 7,000 feet above sea level and was carried by the wind to the southwest. Additional explosive events that could produce minor amounts of ashfall downwind are possible at any time.
The photo below was taken from a UAV (unmanned aerial vehicle) survey of the summit crater on the morning of Sunday, May 20. The crater wall is just visible through the steam plume, showing scars from rockfalls that have been enlarging the crater over the past few days.
UAV flights into this hazardous area, which is too dangerous for ground observations by geologists at this time, allow USGS scientists to better understand what is happening at the rapidly changing vent. In addition to visual imagery such as this, the UAV team hopes to produce digital elevation models to quantify morphological change, and to utilize UAV-borne gas sensors to measure sulfur dioxide and other gas emission. Such information informs our assessment of the hazards that is shared with the National Park Service and other emergency managers.