Images

On April 1, a USGS Hawaiian Volcano Observatory geologist captured this zoomed-in photo of the upper portion of the active lava fountain during Kīlauea's ongoing summit eruption.

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.

Wind conditions during episode 16 of the Kīlauea summit eruption resulted in material from the lava fountains being deposited on Highway 11 on April 1. This photo shows the amount of material, including tephra and Pele's Hair, that had accumulated by 3:30 p.m. HST. A Hawaii County Civil Defense Agency message at 12:49 p.m.

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.

Helicopter overflight view of episode 16 lava fountain and its lava flow on the crater floor of Kaluapele at around noon on April 1, 2025. The lava flow at this time had traveled 2,300 ft (700 m) from the fountain along the floor of Halemaʻumaʻu. USGS photo by D. Downs.

USGS Hawaiian Volcano Observatory geologists captured this aerial view of Kīlauea summit on April 1, 2025, during a helicopter overflight about 3 hours after high fountaining started during episode 16 of the ongoing eruption. USGS photo by N. Deligne.

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

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.

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.

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.

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.

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. USGS photo by C. Gansecki. 

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. 

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. 

On March 25, 2025, the north vent within Halema‘uma‘u crater periodically hosted low-level dome fountains during periods of cyclic lava effusion and drainback. This activity characterized the early stages of episode 15 in Kīlauea's ongoing summit eruption. USGS photo by M. Zoeller.

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 recent fountaining episodes at the summit of Kīlauea have covered the closed portion of Crater Rim Drive in Hawai‘i Volcanoes National Park with a significant amount of tephra. Tephra is the term for volcanic fragments that the travel through the air before being deposited on the ground.