(BIVN) – Episode 37 of the ongoing Kīlauea volcano summit eruption ended abruptly late Wednesday night, after 9.2 hours of continuous fountaining.

The north vent stopped erupting at approximately 11:39 p.m. HST. Ten minutes later, a Magnitude 4.6 earthquake struck the Puna district, and was felt across Hawaiʻi island. Scientists with the USGS Hawaiian Volcano Observatory reported the quake did not appear directly related to the eruption.

“Most earthquakes in this region are caused by movement of the south flank of Kīlauea,” the USGS HVO wrote in an information statement. “The location, depth, and waveforms recorded as part of today’s earthquake are consistent with slip along south flank faults.”

The Observatory provided this initial summary of Episode 37:

No lava fountains or flows erupted from the south vent during episode 37. Dual lava fountains from the north vent reached maximum heights of 500-600 ft (150-180 m). Continuous fountaining lasted for 9.2 hours and produced an estimated 8.2 million cubic yards (6.3 million cubic meters) of lava. The combined average eruption rate was over 200 cubic yards per second (190 cubic meters per second). Lava flows from the fountains covered about 75% of the floor of Halemaʻumaʻu crater. 

The eruptive plume reached heights of more than 14,000 ft (4,200 m) above sea level during episode 37. Volcanic gas emissions greatly decreased after lava fountaining ended. 

The Uēkahuna tiltmeter (UWD) recorded about 16.5 microradians of deflationary tilt during episode 37. The end of lava fountaining was coincident with a rapid change from deflation to inflation at the summit and a decrease in seismic tremor intensity. 

Lava flows from this episode on the floor of Halemaʻumaʻu within the southern part of Kaluapele (Kīlauea caldera) may continue to exhibit slow movement or incandescence as they cool and solidify over the coming days.

The USGS Volcano Alert level for Kīlauea remains at WATCH.