As of 4:30 pm on Monday, December 5, 2022 HVO reports that the Northeast Rift Zone eruption of Mauna Loa continues with one active fissure, (fissure 3) feeding lava flow downslope.

Fissure 3 is generating a lava flow traveling north toward the Daniel K. Inouye Highway that has reached flatter ground and slowed down significantly over the past several days, as expected.

As of 12 p.m. on December 5, the flow front was about 2.15 mi from the Daniel K. Inouye Highway. Several small overflows from main channels were recorded over the past day. During the past 24 hours, the lava flow advanced at an average rate of about 20 feet per hour.

Advance rates may be highly variable over the coming days and weeks. On the flat ground between Mauna Loa and Mauna Kea, lava flows advance more slowly, spread out, and inflate. Individual lobes may advance quickly, and then stall. Additional breakouts may occur if lava channels get blocked upslope. There are many variables at play and both the direction and timing of flow advances are expected to change over periods of hours to days, making it difficult to estimate when or if the flow will impact Daniel K. Inouye Highway.

Sulfur dioxide (SO2) emission rates of approximately 120,000 tonnes per day (t/d) were measured on December 4, 2022. These are decreased from the rate of 180,000 t/d measured on December 1, 2022, but elevated emissions of this magnitude can still have moderate to severe impacts on regional air quality, depending on plume rise rate and wind direction. Volcanic gas is rising high and vertically into the atmosphere before being blown to the west at high altitude, generating vog (volcanic air pollution) in areas downwind. The International Volcanic Health Hazard Network has detailed information about vog: https://vog.ivhhn.org/. Forecasts for the dispersion of vog can be found on the Mauna Loa Vog Forecasting Dashboard: https://vog.ivhhn.org/content/mauna-loa-eruption.

Tremor continues beneath the active fissure which indicates magma is still being supplied to the fissure, and activity is likely to continue.

There is no active lava within Moku’āweoweo caldera nor the Southwest Rift Zone. HVO does not expect any eruptive activity outside the Northeast Rift Zone.

 

Photo credit: New West Broadcasting