USGS Mauna Loa Afternoon Update For Day 5

USGS - The Northeast Rift Zone eruption of Mauna Loa continues, with little change since this morning. One active fissure, fissure 3, is feeding a lava flow downslope. Fissure 4 is sluggish, and fissures 1 and 2 are no longer active. Fissure 3 is generating a lava flow traveling to the north toward the Daniel K. Inouye Highway (Saddle Road) that has reached relatively flatter ground and slowed down significantly over the past couple of days, as expected. As of 7:00 a.m. this morning, the flow front was about 2.7 mi (4.3 km) from the Daniel K. Inouye Highway (Saddle Road). During the previous 24-hour period, the lava flow advanced at an average rate of 150 feet per hour (45 meters per hour). The lava flow remains active. Around fissure 3, a cone is developing; it was measured as approximately 157 (48 m) high today. Fissure 4 continues to be active, but with very little eruptive activity observed this morning. Advance rates may be highly variable over the coming days and weeks due to the way lava is emplaced on flat ground. On flat ground, lava flows spread out and inflate. Individual lobes may advance quickly, and then stall. Additional breakouts may occur if lava channels get clogged upslope. There are many variables at play and both the direction and timing of flow advance 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. Volcanic gas plumes are lofting high and vertically into the atmosphere before being blown to the west at high altitude, generating vog in areas downwind. Vog information can be found at https://vog.ivhhn.org/. Pele's hair (strands of volcanic glass) fragments are being wafted great distances and have been reported as far the Mauna Kea Visitor Information Station. Sulfur dioxide (SO2) emission rates of approximately 180,000 tonnes per day (t/d) were measured on December 1, 2022. Tremor (a signal associated with subsurface fluid movement) continues in the location of 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, 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.