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USGS Volcano Notice for Aviation - DOI-USGS-HVO-2025-07-09T05:16:44+00:00
| (1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) | |
| (2) Issued: | (20250709/1511Z) |
| (3) Volcano: | Kilauea (VNUM #332010) |
| (4) Current Color Code: | ORANGE |
| (5) Previous Color Code: | ORANGE |
| (6) Source: | Hawaiian Volcano Observatory |
| (7) Notice Number: | 2025/H305 |
| (8) Volcano Location: | N 19 deg 25 min W 155 deg 17 min |
| (9) Area: | Hawaii |
| (10) Summit Elevation: | 4091 ft (1247 m) |
| (11) Volcanic Activity Summary: |
Episode 28 of the ongoing Halemaʻumaʻu eruption began at 4:10 a.m. HST on July 9 and is currently exhibiting a vent overflow and fountains reaching roughly 150 feet (45 meters). Past episodes have produced incandescent lava fountains over 1000 feet (300 meters) high that result in eruptive plumes up to 20,000 feet (6000 meters) above ground level. High fountaining associated with this episode has not yet begun but is expected to start soon, as tremor, deflation, and fountain height are all increasing. According to USGS weather stations just southwest of the summit, winds are blowing from the north-northeast direction at approximately 15 miles per hour, which suggests that volcanic gas emissions and volcanic material will be distributed south-southwest. Such trade winds typically turn more to the northeast during daylight hours.
Episode 28 was preceded by gas pistoning cycles, some of which produced small lava overflows at the north vent yesterday. Fountains from the north vent are currently 150 feet (45 meters) high and feeding multiple lava streams at 5 a.m. HST. Inflationary tilt reached approximately 14 microradians since the end of the last episode. Seismic tremor began increasing and tilt at UWD switched from inflationary to slightly deflationary at about 4:15 a.m. HST, a few minutes after lava flows began erupting onto the crater floor. Most episodes of Halemaʻumaʻu lava fountaining since December 23, 2024, have continued for around a day or less and have been separated by pauses in eruptive activity lasting generally at least several days.
No changes have been detected in the East Rift Zone or Southwest Rift Zone. A VAN/VONA will be issued when sustained lava fountaining ceases and the eruption is paused, or earlier if the situation warrants a further update. Kīlauea Volcano Alert Level/Aviation Color Code remain at WATCH/ORANGE. All current and recent activity is within Hawaiʻi Volcanoes National Park. |
| (12) Volcanic cloud height: | Plume in past episodes has reached up to 20,000 feet (6000 meters) above ground level driven by incandescent lava fountains over 1000 feet (300 meters) high |
| (13) Other volcanic cloud information: | Most volcanic ash and pumice (tephra) will fall within about 1 mile (1-2 km) of the eruptive vents. Lower concentrations of finer volcanic particles, such as ash and Pele's Hair, can be transported greater distances downwind of the vent (20 miles or 30 km). Sulfur dioxide emission rate is typically over 50,000 tonnes/day during eruptive episode. |
| (14) Remarks: | Hazard Analysis: This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park. High levels of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are one hazard of concern, as this hazard can have far-reaching effects downwind. As SO2 is continuously released from the summit during an eruption, it will react in the atmosphere to create the visible haze known as vog (volcanic smog) downwind of Kīlauea. SO2 and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/ Another hazard closer to the vent is fallout of Pele's hair and other volcanic fragments from lava fountains. Pele's hair is strands of volcanic glass often produced by lava fountaining activity and can be carried over 10 miles (15 kilometers) from the vent. Other glassy volcanic fragments including Peleʻs hair, volcanic ash, pumice, scoria, and retriculite can fall on the ground within 1-2 miles (1-3 kilometers) of the eruptive vent(s) with the highest concentrations downwind of the vent(s). Strong winds may waft light particles, including Pele's hair, to greater distances downwind. Once they are on the ground, Pele's hair can sometimes cluster and tangle together, giving it the appearance of a tumbleweed. The extent of Pele's hair deposition is dependent on lava fountaining activity and current wind conditions. Residents and visitors should minimize exposure to Pele's hair and other glassy volcanic fragments, which can cause skin and eye irritation. More information about how Pele's hair, its hazards, and what to do is available here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-lava-fountains-highlight-peles-hair-hazards. A recently updated Frequently Asked Questions document that includes information about potential health effects of Pele's hair is available here: https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf Hawaiian lava flows generally advance slowly downslope, and during this eruption flows have been confined to Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera. 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 Kīlauea's caldera rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since late 2007. |
| (15) Contacts: | |
| (16) Next Notice: | A VAN/VONA will be issued when sustained lava fountaining ceases and the eruption is paused, or earlier if the situation warrants a further update. Regularly scheduled daily updates for Kīlauea are posted on the HVO website at https://www.usgs.gov/volcanoes/kilauea/volcano-updates More Information:
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