Images

Kīlauea summit lava fountain from the west end of Halemaʻumaʻu and the tephra blanket it has produced through its 16 episodes. In some places, the tephra blanket reaches more than 5 ft (1.5 m) thick. Most of the tephra from episode 16 lava fountain on April 1, 2025, was blowing to the northwest, with some clasts reaching Highway 11. USGS photo by D. Downs.

On April 1, lava fountains from Kīlauea's ongoing summit eruption prevented geologists from accessing the rim of Halemaʻumaʻu crater within the closed portion of Hawaiʻi Volcanoes National Park. Instead, they hung back along the closed portion of Crater Rim Drive to collect samples of tephra that was intermittently blown in their direction.

Lava fountaining during episode 15 of the summit eruption at Kīlauea volcano. USGS webcam image.

This compilation shows thermal maps made shortly after three different lava fountaining episodes at the summit of Kīlauea. Each fountaining episode produced short-lived lava flows in the western portion of the crater floor, near the vent, which were inactive and solidified by the time of the thermal maps.

View of north vent from the northwest, nearly 12 hours after the end of episode 15 of the eruption at Kīlauea's summit. Tephra covers the slopes of north vent, and the area to the north, giving the appearance of a surface covered in brown sand.

Photo of a tree partially buried and damaged by the tephra deposit produced by the high fountaining on March 26, 2025, during episode 15 of Kīlauea's summit eruption in Halema‘uma‘u. Prior to episode 15, this was a healthy tree growing in a gully, about 130 meters (about 140 yards) west of the rim of Halema‘uma‘u.

A USGS Hawaiian Volcano Observatory geologist takes measurements of the fountain heights during episode 15 of the Kīlauea summit eruption in Halema‘uma‘u. This photo, looking south, was taken at around 10:41 a.m. HST on March 26, during the beginning stages of the high fountains. Fountains from the south vent reached over the top of the crater wall at this time.

During the cyclic low fountain to drainback phase of episode 15, both the north and south vents were active. This low-level activity began March 25 around 9:30 a.m. HST and continued for just over 24 hours before the fountaining phase began. USGS photo by H Winslow.

Lava fountain activity during episode 15 of the Halema‘uma‘u eruption at the summit of Kīlauea. Fountain heights reached up to about 1,000 feet (305 meters) during episode 15. USGS photo by C. Gansecki. 

On March 26, 2025, during the early stages of episode 15 of the Halema‘uma‘u eruption, the north vent exhibited cyclic low fountaining and drainback. Here, the lava lake is at its peak overflowing into lava flows at 8:15 a.m. HST, before draining once again. USGS photo by H Winslow.

Lava fountain activity during episode 15 of the Halema‘uma‘u eruption at the summit of Kīlauea. Fountain heights reached up to about 1,000 feet (305 meters) during episode 15. USGS photo by C. Gansecki. 

USGS Hawaiian Volcano Observatory geologists observed the fountain activity and monitored changing fountain heights during episode 15 of the Halema‘uma‘u eruption. This photo was taken at 1:00 p.m. HST on March 26 during the high fountain stage of the episode. Photo direction is looking south. Fountain heights reached up to about 750 feet (230 meters) at this time.

Lava fountain activity during episode 15 of the Halema‘uma‘u eruption at the summit of Kīlauea. Fountain heights reached up to about 1,000 feet (305 meters) during episode 15. Vigorous lava fountaining feeds lava flows on the floor of Halemaʻumaʻu crater.  USGS photo by C. Gansecki. 

Radar interferograms showing examples of linear subsidence features (indicated by yellow arrows) that occurred directly above recent dike intrusions.

An early morning overflight on March 21 allowed HVO geologists to conduct a new photo survey of the crater floor to measure the volume of erupted material from the latest fountaining episode. Fountaining ended yesterday, March 20, and this morning only a degassing plume was exiting the vents. USGS photo by M. Patrick.
 

The vent craters within Halema‘uma‘u were mostly obscured by the thick degassing plume the morning of March 21, but there were fleeting views of incandescence in the north crater. This photo shows what appeared to be a small collapse of the crater walls exposing hot material deposited from yesterday's fountaining, as opposed to fresh lava in the crater.

As episode 14 lava fountaining occurred during the ongoing Kīlauea summit eruption, the KWcam webcam, F1cam thermal camera and continuous laser rangefinder perched on the crater edge (upper right portion of the photo), provided a continuous record of activity.

Vigorous fountaining began around 6:30 a.m. on March 20, and continued into the early afternoon, as part of episode 14 of the ongoing summit eruption of Kīlauea. In this view from the northeast rim of Kaluapele (the summit caldera), the fountains produce a high outgassing plume, with Mauna Loa on the right side of the photo. USGS photo by M. Patrick.

A telephoto view looking at the top of a lava fountain from episode 14 of the ongoing Halema‘uma‘u eruption. A trio of Koa‘e kea (white-tailed tropicbirds) were flying circles close to the lava fountain, at the summit of Kīlauea, presumably riding the thermal updrafts around the vent. USGS photo by M. Patrick taken on March 20, 2025.

This photo shows the fountaining at Kīlauea summit at about 7:45 a.m. on March 20, during episode 14 of the ongoing eruption. At this time the south fountain was reaching the height of the crater rim, which is about 160 meters (520 feet) above the vent. USGS photo by M. Patrick. 

Just after 7:45 a.m. on March 20, the north fountain at the summit of Kīlauea abruptly shut off during episode 14, and the south fountain rose in height. The height was well above the crater rim, roughly 200 meters (650 feet) above the vent. USGS photo by M. Patrick.