Hazard Notification System (HANS) for Volcanoes


U.S. Geological Survey
Thursday, December 1, 2022, 5:00 PM HST (Friday, December 2, 2022, 03:00 UTC)

19°28'30" N 155°36'29" W, Summit Elevation 13681 ft (4170 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: RED

The Northeast Rift Zone eruption of Mauna Loa continues, with two active fissures feeding lava flows downslope. Fissure 3 remains the dominant source of the largest lava flow. The fissure 3 lava flows are traveling to the north toward the Daniel K. Inouye Highway (Saddle Road) but have reached relatively flatter ground and have slowed down significantly as expected. Advance of the largest flow slowed over the past 24 hours to a rate of about 0.025 miles per hour (40 meters per hour). As of 1:00 p.m. HST today, the flow front is about 3.2 miles (5.2 km) from the Daniel K. Inouye Highway (Saddle Road). Advance rates may be highly variable over the coming days and weeks due to the way lava is emplaced on flat ground. At the rate observed over the past 24 hours, the earliest the lava flow might be expected to reach the Daniel K. Inouye Highway (Saddle Road) is one week. However, there are many variables at play and both the direction and timing of flow advance are fluid and are expected to change over periods of hours to days. 

Fissure 4 is still active with lava flows moving toward the northeast.  The small lobe that was moving to the east from fissure 4 has stalled. Volcanic gas plumes are lofting high and vertically into the atmosphere. Pele's hair (strands of volcanic glass) is falling in the Humu‘ula Saddle area. 

Our seismic monitoring detects tremor (high rates of earthquakes) in the location of the currently active fissures. This indicates that magma is still being supplied, and activity is likely to continue as long as we see this signal.

There is no active lava within Moku'āweoweo caldera, and the Southwest Rift Zone is not erupting. We do not expect any eruptive activity outside the Northeast Rift Zone. No property is at risk currently.

Eruption map for today is available here: https://www.usgs.gov/media/images/december-1-2022-mauna-loa-eruption-map


Residents with questions about emergency response and resources that may be available to assist those at risk should consult https://hawaii-county-civil-defense-agency-hawaiicountygis.hub.arcgis.com/

Hawai‘i Volcanoes National Park has closed the Mauna Loa Road from Kīpukapuaulu and the closure extends to the summit caldera; for more information please see https://www.nps.gov/havo/index.htm.   

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



Next Notice:

HVO Daily Updates on the status of Mauna Loa activity will be posted on the HVO web site at: https://www.usgs.gov/volcanoes/mauna-loa/volcano-updates 

You can receive these updates via email by subscribing to the free Volcano Notification Service at: http://volcanoes.usgs.gov/vns/.

Questions can be emailed to askHVO@usgs.gov

More Information:

Volcanic Hazards: 

Air quality/volcanic gas plume (fissure eruption): High levels of volcanic gas, including sulfur dioxide (SO2) , are emitted from the fissure vents. As SO2 is released from the eruption, it will react in the atmosphere with oxygen, sunlight, moisture, and other gases and particles and within hours to days, convert to fine particles. The particles scatter sunlight and cause the visible haze, known as vog (volcanic air pollution, from “volcanic smog”). Vog creates the potential for airborne health hazards to residents and visitors, damages agricultural crops and other plants, and affects livestock operations.  

Lava flows: Hawaiian lava flows generally advance slowly enough that people can avoid them. They can destroy everything in their paths, including vegetation and infrastructure—which can cut off road access and utilities. Hazards associated with active or recent lava flows include hot and glassy (sharp) surfaces that can cause severe burns, abrasions, and lacerations upon contact with unprotected or exposed skin; uneven and rough terrain can lead to falls and other injuries; hot temperatures that can cause heat exhaustion or dehydration, or in heavy rain can produce steamy ground-fog that can be acidic, severely limiting visibility and sometimes causing difficulty breathing.   

Tephra fall:  Pele's hair and other lightweight volcanic glass fragments from lava fountains and spattering will fall downwind, dusting the ground within a few hundred meters (yards) of the vent. High winds may waft lighter particles and transport them greater distances downwind. Residents are urged to minimize exposure to these volcanic particles, which can cause skin and eye irritation similar to volcanic ash.  

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 and American Samoa.



Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Summary of volcanic hazards from eruptions: https://www.usgs.gov/observatories/hvo/hazards
Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hvo
Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes