HVO/USGS Volcanic Activity Notice

Volcano: Kilauea (VNUM #332010)

Current Volcano Alert Level: WATCH
Previous Volcano Alert Level: ADVISORY

Current Aviation Color Code: ORANGE
Previous Aviation Color Code: YELLOW

Issued: Tuesday, August 24, 2021, 5:34 AM HST
Source: Hawaiian Volcano Observatory
Notice Number: 2021/H238
Location: N 19 deg 25 min W 155 deg 17 min
Elevation: 4091 ft (1247 m)
Area: Hawaii

Volcanic Activity Summary: Kīlauea volcano is not erupting. A swarm of earthquakes beneath the south part of Kīlauea caldera, within Hawaiʻi Volcanoes National Park, began on the evening of August 23, 2021. The swarm continues into the early morning hours of August 24 with a particularly strong sequence of earthquakes that occurred at about 1:30 a.m., HST. The onset of the earthquake swarm was coincident with a change in the style of ground deformation at tiltmeters in the Kīlauea summit region, potentially indicating the shallow movement of magma beneath the south part of Kīlauea caldera.

The US Geological Survey Hawaiian Volcano Observatory is raising the volcano alert level/aviation color code for Kīlauea from Advisory/Yellow to Watch/Orange due to this activity.

HVO will continue to monitor this activity closely and adjust the alert level accordingly.

HVO is in constant communication with Hawai‘i Volcanoes National Park as this situation evolves. The activity is confined entirely within the park.

Stay informed about Kīlauea by following volcano updates and tracking current monitoring data on the HVO web page (https://www.usgs.gov/volcanoes/kilauea/volcano-updates) or by signing up to receive updates by email at this site: https://volcanoes.usgs.gov/vns2/.

Recent Observations:
[Volcanic cloud height] None.
[Other volcanic cloud information] None.
[Lava flow/dome] None.
[Ballistics] None.
[Lava flow] None.

Hazard Analysis:
[General hazards] unknown
[Ash cloud] unknown
[Ashfall] unknown
[Lava flow/dome] unknown
[Mud flow] NA
[Other hazards] unknown
[Volcanic gas] unknown
[Lava flow] unknown

Remarks: The US Geological Survey Hawaiian Volcano Observatory has detected an increase in earthquake activity beneath the south part of Kīlauea summit caldera, within Hawaiʻi Volcanoes National Park. The activity began around 4:30 p.m., HST, on August 23 and continued through the night and into the early morning of August 24, 2021. The swarm was accompanied by an increase in the style of ground deformation recorded by the Sandhill tiltmeter, just to the west of the earthquake swarm location. The same tilt increase was also recorded by the tiltmeter near Uēkahuna Bluff and the site of the old HVO building.

At about 1:30 a.m. this morning, the swarm of earthquakes intensified in this region; this activity may indicate an intrusion of magma occurring 1–2 km (0.6–1.2 miles) beneath the south caldera.

Over 140 earthquakes have been recorded as of 4:30 a.m. on August 24; the largest recorded earthquake was magnitude 3.3 with the majority of earthquakes less than magnitude 1. Small earthquakes are continuing at a rate of at least 10 detected earthquakes per hour.

Currently, webcams and satellite imagery show no evidence of lava at the surface. HVO scientists will continue the monitor the situation and will issue additional messages and alert level changes as warranted by changing activity.

For discussion of Kīlauea hazards, please see:

https://www.usgs.gov/observatories/hawaiian-volcano-observatory/hazards

More Information:
Kīlauea activity summary also available by phone: (808) 967-8862
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
Kīlauea FAQs: https://www.usgs.gov/volcanoes/kilauea/faqs

Contacts: askHVO@usgs.gov

Next Notice: The Hawaiian Volcano Observatory (HVO) continues to closely monitor Kīlauea's seismicity, deformation, and gas emissions for any changes in activity. HVO will now issue daily Kīlauea updates until further notice.

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

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

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.