Courtesy of USGS - Hawaiian Volcano Observatory
This is an exciting time on Kīlauea volcano because lava has returned to the summit. On September 29, 2021, earthquake activity increased abruptly beneath Halemaʻumaʻu around 2 p.m. HST, and at 3:21 p.m. a series of vents opened in the floor and walls of Halemaʻumaʻu crater, generating a lava lake. This activity is ongoing, and Kīlauea daily updates are posted daily.
Hazard Analysis:Hazard Analysis: This eruption at Kīlauea's summit is occurring within a closed area of Hawaiʻi Volcanoes National Park. High levels of volcanic gas are the primary hazard of concern, as this hazard can have far-reaching effects downwind. Large amounts of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are continuously released during eruptions of Kīlauea Volcano. As SO2 is released from the summit, it reacts in the atmosphere to create the visible haze known as vog (volcanic smog) that has been observed downwind of Kīlauea. Vog creates the potential for airborne health hazards to residents and visitors, damages agricultural crops and other plants, and affects livestock.
Additional hazards include Pele's hair and other lightweight volcanic glass fragments from lava fountains that will fall downwind and dust the ground within a few hundred meters (yards) of the erupting fissure vent(s). Strong winds may waft lighter particles to greater distances. Residents should minimize exposure to these volcanic particles, which can cause skin and eye irritation.
Other significant hazards also remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. This underscores the extremely hazardous nature of the rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since early 2008.