(BIVN) – The USGS Hawaiian Volcano Observatory on Wednesday shared new photos of the Kīlauea summit caldera, taken during a morning overflight, showing the aftermath of the most recent lava fountaining episode. 

Episode 31 of the ongoing summit eruption began on the afternoon of August 22 and ended over 12 hour later on August 23. 

“Elevated degassing continues from the vent,” the USGS HVO wrote on Monday. “Average sulfur dioxide (SO2) emission rates during inter-episode pauses are typically 1,200 to 1,500 t/d, though emission rates vary on short time scales in association with gas-pistoning.”

USGS: “During a Kīlauea summit monitoring overflight on August 25, 2025, USGS Hawaiian Volcano Observatory field crews documented the geometry of the north vent that fountained predominantly during episode 31. The conduit is at a high angle into the southwest wall of the north vent.” (USGS photo by K. Lynn)

Lava flows from Episode 31 covered more than 75% of the floor of Halemaʻumaʻu within the southern part of the caldera. Parts of the lava flow continued to glow Sunday night into Monday morning.

Unlike many recent Kīlauea summit eruption episodes, Episode 31 featured a primary lava channel exclusively fed by molten spatter, rather than lava upwelling from the north vent, scientists reported during the event.

USGS: “During a Kīlauea monitoring overflight on August 25, 2025, USGS Hawaiian Volcano Observatory field crews documented the proximal channel that fed lava flows from the north vent to the floor of Halema‘uma‘u during episode 31. This image, looking to the north (the north vent is just out of sight to the bottom of the photo), shows the proximal Pāhoehoe channel flanked by lighter brown tephra deposits to the left and right.” (USGS photo by K. Lynn)

The USGS HVO on Monday offered this outlook for the start of Episode 32:

The rapid rebound of tilt, weak glow, and seismicity characteristic of gas pistoning all indicate episode 32 is likely. The current forecast window is during the first week of September or later if there are unexpected changes in inflation rate.

The USGS Volcano Alert Level for Kīlauea remains at WATCH.