UPDATE – (6:50 a.m. – April 17) – Things were quiet Thursday morning, following the start of Episode 18 at the summit of Kīlauea volcano. 

The eruption of lava from the north vent that began Wednesday night at 10:01 p.m. HST ended at 11:21 p.m. HST that same night. 

“The summit continued to inflate throughout this precursory activity,” the USGS Hawaiian Volcano Observatory wrote in a Thursday morning update. “Episode 18 fountains may start as late as Saturday or Sunday.” 

USGS view of the summit vents on Thursday morning.

(BIVN) – Episode 18 in the ongoing Kīlauea summit eruption began on Wednesday night. 

Scientists with the USGS Hawaiian Volcano Observatory reported the new episode began at 10:01 p.m. HST on April 16, when lava started overflowing from the north vent in Halemaʻumaʻu. 

USGS webcams captured live video of the activity as it happened. 

USGS webcam shows the start of Episode 18 in the ongoing Kīlauea summit eruption.

From a USGS HVO status report issued at 10:26 p.m. HST:

Episode 18 was preceded by glow from the south vent that increased at about 9:10 p.m. HST on April 16 and began regular spattering at 10-20 seconds apart. Spatter bursts continued to increase in size and frequency until about 9:30 p.m. HST when 10-15 foot high (3-5 meters high) dome fountains began. Lava level within the vent continued to rise until the lava pond became visible at 9:45 p.m. HST. Currently the eruption is feeding lava flows that extend down the north vent spillway and a short distance onto the Halemaʻumaʻu crater floor.

UWD tilt is relatively flat at this time but an increase in seismic tremor that began at 9:30 p.m. HST continues.

Emissions of SO2 gas are elevated, and during recent episodes have reached 20,000 to 50,000 tonnes per day or more. Similar amounts of gas are expected to accompany any high fountaining activity that may occur during episode 17. In addition, visitors to Hawaiʻi Volcanoes National Park and residents of adjacent areas may be exposed to Peleʻs hair and other small fragments of volcanic glass and tephra being carried in the plume, as they were during episode 16.

Each episode of Halemaʻumaʻu lava fountaining since December 23, 2024, has continued for between 13 hours to 8 days, and episodes have been separated by pauses in eruptive activity lasting less than 24 hours to 12 days.

The USGS Alert Level for Kīlauea remains at WATCH.