Images

During a monitoring overflight on April 9, 2025, USGS Hawaiian Volcano Observatory field crews observed that the ponded lava in the north vent from April 8 had drained and/or collapsed. The south vent was still active, with fountaining sending lava flows across the floor of Halema‘uma‘u. USGS photo by K. Lynn. 

This thermal map was taken on the 7 a.m. overflight of Kīlauea summit on April 9, 2025, and shows the expansive lava flow covering the floor of Halema‘uma‘u, supplied by lava fountains at the vent. As in earlier episodes, the lava exited the vent into a short channel that fed a broad perched lava pond.

This photo shows the low fountaining in the south vent, at the summit of Kīlauea, just minutes before the fountaining ended at 9:45 a.m. HST on April 9, 2025. Visibility in the caldera was variable this morning with passing showers. USGS photo by M. Patrick.

A USGS Hawaiian Volcano Observatory geologist collects a molten lava sample for geochemical analysis, which will inform hazard analyses of the ongoing eruption. This lava flow was supplied by lava fountaining in the western end of the crater, during episode 17 of the ongoing summit eruption of Kīlauea. USGS photo by M. Patrick.

During a monitoring overflight at 7:15 a.m. HST on April 9, 2025, USGS Hawaiian Volcano Observatory field crews observed Pāhoehoe flows on the floor of Halema‘uma‘u crater at the summit of Kīlauea. These flows were fed by the south vent fountains, which ceased activity around 9:45 a.m. this morning, April 9, marking the end of episode 17. USGS photo by E.

Following the onset of the Kīlauea summit eruption's seventeenth episode in the late evening of April 7, USGS Hawaiian Volcano Observatory geologists visited the southern rim of Halemaʻumʻau crater on the morning of April 8 to observe vent activity.

Episode 17 of the ongoing Halemaʻumaʻu eruption at the summit of Kīlauea began last night, April 7, with lava flows erupting from the south vent at 10:15 p.m. HST. Low lava fountaining (100 feet, or 30 meters) was active overnight and continues this afternoon, feeding a lava flow on the crater floor.  USGS photo by M. Zoeller. 

In the afternoon of April 8, USGS Hawaiian Volcano Observatory geologists visited the western rim of Halemaʻumaʻu crater to observe the ongoing Kīlauea summit eruption during its seventeenth episode. This telephoto view of the geologists shows them taking laser rangefinder measurements of lava fountains at the active eruptive vent below them within the crater.

While the south vent within Halemaʻumaʻu crater at the summit of Kīlauea has been actively fountaining on April 8, the north vent has hosted a lava pond with weak spatter. At times, this pond has overflowed to feed short lava flows down the flanks of the vent structure. USGS photo by M. Zoeller. 

As the day progressed on April 8, despite continued lava fountaining at the south vent (background right), activity declined at the north vent (foreground left). This afternoon photo captured from the western rim of Halemaʻumaʻu crater—looking to the south—shows the north vent's lava pond fully crusted over and sitting lower within the spatter cone.

This close-up thermal map shows the crater floor at the summit of Kīlauea just an hour after the end of episode 16 lava fountaining on April 2. This map provides a good example of the different zones of lava flow activity on the crater floor that have been observed in many of the eruptive episodes.

This set of thermal maps shows activity near the beginning and just after the end of episode 16 lava fountaining at the summit of Kīlauea. On April 1, lava fountaining was reaching over 200 meters (660 feet) and was beginning to produce a lava flow covering the western portion of the crater floor.

Ground tilt associated with episodic eruptions at Kīlauea. Top panel, two years of summit tilt spanning episodic fountaining at Maunaulu in 1969, as measured by a watertube tiltmeter at Uēkahuna  bluff.  Middle panel, an ideal aerosmith measurement of summit ground tilt during the initial years (1984-1986) of the Puʻuʻōʻō eruption that span a period o

Lava fountaining during episode 16 of the ongoing summit eruption at Kīlauea. USGS webcam image. 

During a monitoring flight on April 2, 2025, USGS Hawaiian Volcano Observatory geologists captured this aerial view of Halemaʻumaʻu, within Kaluapele (Kīlauea summit caldera), just after the end of episode 16 of the ongoing eruption.

During each eruptive episode in Halemaʻumaʻu, tephra is deposited on the crater rim downwind within the closed area of Hawaiʻi Volcanoes National Park. This sign for the Southwest Rift Zone of Kīlauea, which used to stand at least 6 feet (2 meters) above the ground surface, provides a visual for how thick the tephra deposit is at this location. USGS photo by K.

Episode 16 of the ongoing eruption in Halemaʻumaʻu stopped just after noon today, April 2, 2025. On a USGS Hawaiian Volcano Observatory monitoring overflight within the hours following its end, the crater floor was a patchwork of active and inactive lava flows.

Aerial view of Kaluapele, the summit caldera of Kīlauea, hours after the end of episode 16 of the ongoing eruption in Halemaʻumaʻu. USGS photo by K. Lynn. 

USGS Hawaiian Volcano Observatory geologists captured this view during a monitoring overflight just after noon on April 2, 2025, following the end of episode 16 of the ongoing eruption in Halemaʻumaʻu.

USGS Hawaiian Volcano Observatory geologists landed briefly on the floor of Halemaʻumaʻu crater and captured this image of an active ʻaʻā lava flow. Episode 16 of the ongoing eruption at Kīlaeua summit had ended a couple of hours prior to this photo being taken, and several lava flows retained residual activity at the time of the monitoring overflight.

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.