Images

Late in the afternoon on Sunday, February 15, USGS Hawaiian Volcano Observatory scientists monitoring Kīlauea summit eruption episode 42 hiked west of Halema‘uma‘u crater for an angle of both the north and south vent lava fountains side by side. During most of episode, the south vent lava fountain (right) was slightly taller than the north vent's (left).

On Sunday, February 15, USGS Hawaiian Volcano Observatory scientists monitored episode 42 of the Kīlauea summit eruption from the northwest rim of Halema‘uma‘u crater. Despite driving rains, this location provided good views of the north vent's lava fountains and flows on the crater floor. Around 4:20 p.m.

A telephoto view of the base of the two lava fountains, and the narrow gap that was present between them, during episode 42 of the Kīlauea summit eruption on February 15, 2026. On the south side of the north fountain (right), a very small third fountain was active, with frequent bubble bursting. USGS photo by M. Patrick.

The KWcam is located on the northwest rim of Halemaʻumaʻu crater at the summit of Kīlauea. The camera is one of many located around the Kaluapele, Kīlauea summit caldera, that aid in monitoring conditions. This image was captured 6:26 p.m. on February 15, 2026, during episode 42 of lava fountaining. USGS photo. 

Photograph of the north vent fountain during episode 42, taken from the northwest rim of Halema‘uma‘u crater on February 15, 2026. Semi-molten clasts feed a small ‘a‘ā lava flow carrying lava north from the base of the north vent lava fountain within the caldera.

Gas and tephra plume from Kīlauea summit episode 42 as observed from the Footprints Trail in Hawai‘i Volcanoes National Park at about an hour and a half after this episode started. The plume at this time had risen to over 20,000 ft (over 6,000 m) above ground level. Trade winds were blowing and deposited tephra to the southwest of the north and south vents.

At brief moments during episode 42 Kīlauea summit lava fountaining on February 15, 2026, the south (left) and north (right) fountains were similar in height, and wispy fingers of gas and small particles from the two fountains mingled in the gap between them. USGS photo by M. Patrick.

View of Kaluapele (Kīlauea's summit caldera) from the B1 webcam on February 6, 2026, acquired between lava fountaining episodes 41 and 42.

This annotated photograph shows the different size categories of tephra associated with recent lava fountaining episodes at the summit of Kīlauea. The inset photo on the bottom left shows the vesicular (bubble-rich) texture of most of these clasts. The smallest particles of tephra are volcanic ash, and they are smaller than 1/16 of an inch (2 mm).

USGS Hawaiian Volcano Observatory staff participated in a monitoring overflight of Kīlauea summit caldera, Kaluapele, the morning of February 4, 2026, to investigate and collect samples of the episode 41 lava flows that were emplaced on January 24, 2026. These lava flows covered most of the crater floor during the lava fountaining episode. USGS photo by D.

USGS Hawaiian Volcano Observatory geologists captured this view during a morning helicopter monitoring overflight of Kīlauea summit caldera, Kaluapele, on the morning of February 4, 2026. Despite glow present on the USGS livestream cameras overnight, no lava or incandescent material was visible in the north (right) and south (left) vents. USGS photo by D. Downs.

Image of an olivine crystal taken with a petrographic microscope. A) Olivine with melt inclusion (honey color) with a vapor gas bubble inside it (black circle). B) Zoomed in view of olivine highlighting a fluid inclusion (black circle, white dot in center) and a melt inclusion. USGS images. 

University of Hawaiʻi at Hilo undergraduates using the petrographic microscope to identify fluid inclusions within olivine crystals. USGS photo. 

This map shows the tephra fall associated with episode 41 of Kīlauea's episodic summit eruption, on January 24, 2026. Tephra is a generic word for any material erupted by a volcano that travels through the air before landing on the ground.

Satellite image of Kīlauea summit taken on January 28, 2026, and showing the caldera and a plume of volcanic gas. Image credit: WorldView ©2025 Maxar, USG Plus.

Tephra is a word that describes any material erupted by a volcano that travels through the air before landing on the ground. Volcanic ash is tephra particles that are less than 2 mm in size (less than 0.08 in).

A piece of reticulite, a very frothy type of tephra full of bubbles, remains perched on top of a Hapuʻu tree fern frond in Volcano Village on January 27, 2026. This material was erupted during episode 41 lava fountaining at the summit of Kīlauea on January 24, 2026. USGS photo by K. Mulliken. 

Volcanic ash is washed off a road in Volcano Village on January 27, 2026, and coats the plants adjacent to the road. USGS photo by K. Mulliken. 

Tephra clean-up efforts on Highway 11, near the entrance to Hawaiʻi Volcanoes National Park, on January 26, 2026. Water was sprayed on the pavement before machinery scrubs the pavement to remove the tephra particles.

Tephra fall from episode 41 of Kīlauea summit eruption included pieces of reticulite, frothy rocks full of bubbles made by gas within lava expanding (which drives the lava fountaining process). These pieces of rock are very lightweight and glassy, which makes them very easy to crush.

Tephra fall from episode 41 of lava fountaining at the summit of Kīlauea on a picnic table in Hawaiʻi Volcanoes National Park. USGS photo by K. Mulliken.