Over the past few days, the Mauna Loa eruption has been slowing to the point where there’s no longer anything to see. At the same time, Kilauea pauses its activity for the first time in over a year.
For days now, the eruption at Mauna Loa has been winding down. At first, Vent 3 on the volcano’s Northeast Rift Zone stopped feeding the flow that was threatening the Daniel K. Inouye Highway. Then, output at Vent 3 fell to the point that it was no longer feeding any flows, nor was it fountaining. Currently, Vent 3 has reduced “residual incandescence” while gas emissions have declined precipitously. Tremors have also ceased, indicating that magma movement within Mauna Loa has slowed or stopped. However, the USGS reports that inflation continues at the mountain, which means that Mauna Loa’s magma chamber could be recharging.
Despite the inflationary action occurring on Mauna Loa, there is no reason to believe a new eruptive phase will begin. Historical data shows that once an eruption on the mountain slows and stops, it doesn’t usually restart. Anything is possible, though, and the Hawaii Volcanoes Observatory remains on high alert.
In an odd coincidence, as activity at Mauna Loa came to a halt, Kilauea pauses its eruption too. The USGS reports that, as of Sunday, December 11, all activity at Halema’uma’u Crater has ceased, and the lava lake within has completely crusted over. Like at Mauna Loa, volcanic gas emissions at Kilauea have reduced dramatically, while seismic activity has gone completely silent. However, unlike at Mauna Loa, tilt meters atop Kilauea show no signs of ground deformation at this time, indicating that Kilauea’s magma chamber isn’t recharging right now.
One theory regarding Kilauea’s pause is that Mauna Loa’s eruption depressurized the magma system that feeds both volcanoes enough to relieve any eruptive pressure on Kilauea. It could also be why Mauna Loa stopped erupting, despite ongoing inflation at its summit.
I’m disappointed I didn’t get over to see Mauna Loa erupting. Such an event is potentially a once-in-a-lifetime one and was very awe-inspiring. But I’m doubly disappointed that I may have missed yet another eruption as Kilauea pauses, bringing an end to any volcanic activity on the Big Island, at least for now.