Images

A helicopter can be seen in the upper left portion of the photo, with USGS Hawaiian Volcano Observatory geologists onboard conducting a photogrammetric survey of Halema‘uma‘u crater floor following the episode 31 lava fountaining on August 22-23, 2025. The passive outgassing plume originates from the vent complex that has been active in the current eruption.

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.

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.

A helicopter carries USGS Hawaiian Volcano Observatory geologists over Wahinekapu (Steaming Bluff) as it flies over Kīlauea's summit caldera to conduct a photo survey following the episode 31 lava fountaining. Mauna Loa can be seen in the distance. USGS photo by M. Patrick.

Lava fountains at the summit of Kīlauea during episode 31. Afternoon views of the eruption from the northwest caldera rim provided views of the inclined lava fountain from the north vent, as well as the eruption plume. During eruption episodes, sulfur dioxide (SO₂) emission rates increase.

With permission from Hawaiʻi Volcanoes National Park, USGS Hawaiian Volcano Observatory staff monitor and document episode 31 of the ongoing eruption at the summit of Kīlauea volcano, which began on August 22.

On August 22, USGS Hawaiian Volcano Observatory scientists hiked to the western rim of Halemaʻumaʻu crater to watch episode 31 of the ongoing Kīlauea summit eruption. Hiking across tephra fields from earlier lava fountaining episodes, renewed eruptive activity was evidenced by a stronger volcanic gas plume as well as heat shimmer above the crater. USGS photo by M.

Inclined lava fountains from Kīlauea summit eruption episode 31 on August 22 have blanketed the Halemaʻumaʻu crater floor with tephra, in addition to feeding lava flows extending to the east. USGS photo by M. Zoeller. 

As the sun sets on August 22, a lava fountain continues to erupt within Halemaʻumaʻu crater at the summit of Kīlauea. This is the 31rst episode of lava fountaining in Halemaʻumaʻu since this eruption began on December 23, 2024. USGS photo by M. Patrick. 

31 episodes of lava fountaining at the summit of Kīlauea since December 23, 2024, have covered the floor of Halemaʻumaʻu with a patchwork of lava flows of varying ages. With each episode, more of the crater floor is covered and in total, the lava flows have filled over 260 feet (80 meters) of the crater with new lava.  USGS photo by M. Patrick.

During Kīlauea summit eruption episode 31 on August 22, inclined lava fountains extended 300 meters (1000 feet) laterally from the north vent, going eastward towards the center of Halemaʻumaʻu crater.

Unlike many recent Kīlauea summit eruption episodes, number 31 on August 22 has had a primary lava channel exclusively fed by molten spatter, rather than lava upwelling from the north vent. Other more solid tephra has fallen in a broad plain around the vent.

Episode 31 fountains began at 2:04 p.m. HST, after spattering was visible overnight along with several sluggish lava flows from the north vent.  After episode 31 started, lava fountains steadily grew in size to over 325 feet (100 m). The fountains exited the north vent at a 45-degree angle and would be over 500 feet high if they were straight up.

COSMO-SkyMed Second Generation (CSG) interferogram for the period from August 2 to August 10, 2025, covering Kīlauea volcano’s summit region.

On August 18, USGS Scientist Mike Zoeller with the Hawaiian Volcano Observatory, a Hawai‘i Volcanoes National Park park ranger, and two researchers from the University of Colorado conducted UAS (uncrewed aircraft system) work in the vicinity of Halemaʻumaʻu crater at Kīlauea volcano.

On August 18, USGS Scientist Mike Zoeller with the Hawaiian Volcano Observatory, a Hawai‘i Volcanoes National Park park ranger and two researchers from the University of Colorado conducted UAS (uncrewed aircraft system) work in the vicinity of Halemaʻumaʻu crater at Kīlauea volcano. In this photo, staff monitor the UAS remotely and take photos for analysis.

On August 18, field observations at the summit of Kīlauea confirmed that lava was moving up inside the north vent. While perched lava was not observed, lava spatter was visible intermittently during gas pistoning events. USGS photo by H. Weiss-Racine. 

This photo was taken on August 18, looking southeast toward the large tephra deposit that has accumulated since the episodic eruptions at Halemaʻumaʻu crater at Kīlauea volcano began in late December of 2024. The tephra deposit is now about 75 feet (about 23 meters) thick.

On August 18, USGS scientists visited the rim of Halemaʻumaʻu crater at the summit of Kīlauea volcano to view the north vent. The goal of the observation was to confirm if lava was moving up inside the vent. While perched lava was not observed, lava spatter was visible intermittently during gas pistoning events.   

This close-up view of the Kīlauea summit eruption's north vent was captured during an uncrewed aircraft system (UAS) overflight conducted by Hawaiian Volcano Observatory scientists on August 18. Looking down to the southwest, the Halema‘uma‘u crater wall is out of view to the top of the frame.

Sand and large, wave-rounded boulders frame the edge of the 2018 Kīlauea lava delta near Isaac Hale Beach Park. Wave action has eroded these boulders from the 2018 lava flow and deposited them on the beach. USGS photo.