Mauna Loa transitions into slow moving lava flow

Securely Travel traveled to the Mauna Loa volcano this week and witnessed first hand the lava flow along the remaining active fissure, which the USGS has labeled number three. This fissures is pumping out hundreds of tons of lava each second and spewing gases into sky. The prevailing winds push the gases, known as VOG toward the down wind communities to the southwest.

The County of Hawaii opened up “Old Saddle Road” for the public to transit and get close (but a safe distance away) of the lava flow from Mauna Loa. At 0400 in the morning, hundreds of vehicles were on the 4.5 mile loop moving, stopping, taking photos and enjoying the show being put on by the volcano. The County put a 90 minute limit on the 4.5 mile transit, which seemed to be just the right amount of time.

Securely Travel’s photo gallery

Of course with every endeavor, there will be those who abuse the privilege and three hikers were apprehended trying to cross the old lava fields outside the permitted area to get closer to the active lava flow. Perhaps had they been permitted to continue Darwin would have intervened.

On 04 December the volcano alert warning level was lowered from RED to ORANGE, as the eruption is now occurring only out of the fissure on the northern slope and poses no threat to the Big Island community. Great speculation remains, however, on whether or not the lava flow will continue to push the last two miles remaining between its current reach and the cross-island DKI highway. The current movement of the lava is 40 feet per hour.

The eruption has now focused at a single vent, fissure 3, at an elevation of 11,500 ft (3510 m) along the Northeast Rift Zone of Mauna Loa. Lava fountaining at the vent has been approximately 100 feet (33 m) tall over the past day, depositing fragments of volcanic material in the area near the vent. Pele’s hair (small strands of volcanic glass) are being wafted great distances and have been reported as far as Laupāhoehoe, a community on the northeast coastline of the Island of Hawai’i about 23 miles (37 km) north of Hilo and 37 mi (59 km) northwest of fissure 3.   

Sulfur dioxide (SO2) emission rates of approximately 180,000 tonnes per day (t/d) were measured on December 1, 2022 and remain elevated at this time. 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 Vog Forecasting Dashboard: http://weather.hawaii.edu/vmap/new/ 

Fissure 3 is generating a lava flow traveling to the north toward the Daniel K. Inouye Highway (Saddle Road) that has reached flatter ground and slowed down significantly over the past several days, as expected. As of 7 a.m. today, December 4, the flow front was about 2.3 mi (3.6 km) from the Daniel K. Inouye Highway (Saddle Road). During the past 24 hours, the lava flow advanced at an average rate of about 40 feet per hour (12 meters per hour). Though the advance rate has slowed over the past several days, the lava flow remains active with a continuous supply from the fissure 3 vent.   

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.   

Tremor (a signal associated with subsurface fluid movement) continues beneath the currently active fissures. This indicates that magma is still being supplied to the fissure, and activity is likely to continue as long as we see this signal.  

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