Kīlauea

HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Friday, April 30, 2021, 7:30 AM HST (Friday, April 30, 2021, 17:30 UTC)

KILAUEA VOLCANO (VNUM #332010)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Activity Summary: Kīlauea Volcano is erupting. Lava activity is confined to Halemaʻumaʻu with lava erupting from a vent on the northwest side of the crater. This morning, April 30, the lava lake was 227 m (744 ft) deep and remains stagnant over its eastern half. SO2 emission rates remain elevated at 375 t/day, last measured on April 25.

Summit Observations: The most recent sulfur dioxide emission rate, measured on April 25, was 375 t/day. This is elevated compared to rates in the months before the eruption started on December 20 (less than 100 t/day), but lower than emission rates from the pre-2018 lava lake (around 5,000 t/day). Summit tiltmeters recorded minor change over the past 24 hours. Seismicity remains stable, with elevated tremor.

East Rift Zone Observations: No unusual activity noted in the region. Geodetic monitors indicate that the summit and upper East Rift Zone—between the summit and Puʻuʻōʻō—is refilling at rates similar to those measured over the past 2 years and before the December 2020 eruption. SO2 and H2S emissions from Puʻuʻōʻō were below instrumental detection levels when last measured on January 7.

Halemaʻumaʻu Lava Lake Observations: Lava effusion from the west vent continues to supply the lava lake within Halema‘uma‘u crater through a submerged inlet to the lake. Lava circulation and intermittent foundering of crust continue in a smaller western portion of the lava lake, and lava has not oozed out along the perimeter of the lake over the past week. The total depth of the lake is 227 m (744 ft) this morning as measured by a continuous laser rangefinder on the active western portion. Stagnant and solidified lava crust covered 93% of the lake surface as measured by thermal mapping on April 16th.

Recent SO2 emission rate measurements suggest that the effusion (eruption) rate has decreased over the past week. Past decreases in emissions have occurred while summit tilt was decreasing whereas the recent drop in emissions occurred while summit tilt was slowly increasing during the last week. It is common for eruptions to wax and wane or pause completely. It is unclear if the current decrease in activity will continue and hazardous conditions remain around Halema‘uma‘u crater. HVO continues to monitor Kīlauea volcano closely for any signs of change in activity.

Near-real time webcam views of the lava lake can be found here: https://www.usgs.gov/volcanoes/kilauea/webcams.

Hazard Analysis: High levels of volcanic gas are the primary hazard of concern regarding the ongoing activity at Kīlauea’s summit, with additional hazards from crater wall instability and rockfalls. 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 will react 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. The unstable nature of the crater rim is a hazard surrounding Halemaʻumaʻu crater, an area that has been closed to the public since early 2008. Pele's hair and other lightweight volcanic glass fragments from the lava fountains within Halemaʻumaʻu will fall downwind of the fissure vents and lava lake, dusting the ground within a few hundred meters (yards) of the vent. Strong winds may waft lighter particles to greater distances. Residents should minimize exposure to these volcanic particles, which can cause skin and eye irritation similar to volcanic ash.

Vog information can be found at https://vog.ivhhn.org/.

Please see this Hawaiʻi Volcanoes National Park Press Release “How to Safely View the New Eruption in Hawaiʻi Volcanoes National Park” at https://www.nps.gov/havo/learn/news/20201221_nr_new-summit-eruption-kilauea.htm.

The Hawaiian Volcano Observatory (HVO) continues to closely monitor Kīlauea’s seismicity, deformation, and gas emissions, and maintains visual surveillance of the summit and the East Rift Zone. HVO will continue to issue daily updates and additional messages as needed.

MORE INFORMATION:
Kīlauea activity summary also available by phone: (808) 967-8862

Subscribe to these messages: https://volcanoes.usgs.gov/vns2/

Kīlauea webcam images: https://www.usgs.gov/volcanoes/kilauea/webcams

Kīlauea photos/video: https://www.usgs.gov/volcanoes/kilauea/photo-video-chronology

Kīlauea lava-flow maps: https://www.usgs.gov/volcanoes/kilauea/maps

Definitions of terms used in update: https://volcanoes.usgs.gov/volcanoes/kilauea/extra/definitions.pdf

Summary of volcanic hazards from Kīlauea eruptions: https://volcanoes.usgs.gov/volcanoes/kilauea/extra/hazards.pdf

Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hawaiian-volcano-observatory/earthquakes

Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/natural-hazards/volcano-hazards/about-alert-levels

CONTACT INFORMATION:

askHVO@usgs.gov

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawaiʻi.