U.S. Geological Survey scientists are closely monitoring Hawaii’s Kīlauea volcano as underground magma chambers repressurize, signaling that a 56th episodic lava fountain may erupt during the first full week of November.
On Friday, the USGS revised its forecast window, determining that fountaining will most likely start between Nov. 2 and Nov. 9, FOX Weather reported. The Hawaiian Volcano Observatory had previously issued forecast projections spanning from late October through Nov. 7, but shifting ground movement patterns led geologists to adjust their timeline.
Signs of reinflation at the summit
Following episode 55 on Oct. 17, instruments around Kaluapele, Kīlauea’s summit caldera, tracked typical post-eruption recovery. Tiltmeters placed near Halemaʻumaʻu crater recorded an outward ground swelling of more than 13 microradians, reversing a substantial part of the 21 microradians of deflation recorded during the prior burst, according to observatory updates cited by Big Island Video News.
Scientists also reported seeing an intermittent glow at the west vent alongside a dimmer incandescence at the north vent. The south vent has remained unlit since becoming smothered under volcanic debris during the mid-October eruption, FOX Weather and Big Island Video News reported. In addition, seismic monitors recorded continuous ground tremors and detected four weak earthquakes registering at magnitude 1.5 or lower in the caldera area.
Predicting an unpredictable cycle
The current pattern of episodic fountaining began on Dec. 23, 2024. For nearly two years, fountaining episodes have erupted on a semiregular basis, usually persisting for under 12 hours before pausing as magma replenishes below ground. By linking magma chamber pressure and ground swelling to eruptive cycles, researchers have developed quantitative forecast models to alert the public, as detailed in a study published in the journal Science and reported by Earth.com.
Forecasting the exact onset of episode 56, however, has proven more complicated. Prior to episode 55, Kīlauea entered an atypical two-month lull after episode 54 concluded on Aug. 25. That period featured erratic tilt measurements and the emergence of several short-lived vents. A shallow body of magma pushed beneath the caldera from Sept. 30 to Oct. 1, generating earthquake swarms before eruptive activity resumed, according to USGS details published by Kauai Now.
When episode 55 finally broke out on Oct. 17, lava blasted approximately 720 feet above the north vent, propelling a plume of volcanic gas and tephra to an altitude of 25,000 feet before the burst abruptly ended after roughly six hours, Earth.com reported.
Kīlauea remains at an Advisory alert level, with an aviation code of Yellow. During pauses between fountains, the summit emits between 1,000 and 5,000 tonnes of sulfur dioxide daily, which drifts across the Kaʻū Desert to create volcanic smog downwind. All lava erupted during the 55 episodes has remained confined to Halemaʻumaʻu inside a closed section of Hawaiʻi Volcanoes National Park, and scientists continue tracking data to see whether inflation rates will solidify the eruption timeline.
