During a USGS Hawaiian Volcano Observatory Kīlauea eruption monitoring overflight on March 4, 2025, geology field crews sampled a viscous molten lava flow on the eastern margin of the lake. This flow is likely an ooze out from the molten lake interior, and represents lava erupted in previous episodes. This sample will help USGS Hawaiian Volcano Observatory scientists identify the previously erupted component of the samples from each recent eruption episode, which contributes to ongoing eruption hazard assessment. This view is to the west, with the vents in the background not visible due to the topography. USGS photo by K. Lynn.

Coincident with a scheduled USGS Hawaiian Volcano Observatory eruption monitoring overflight the morning of Tuesday, March 4, 2025, Kīlauea's ongoing eruption in Halema‘uma‘u started to show minor activity at both eruptive vents. This aerial view of the vents taken at 8:04 a.m. HST shows a small new lava flow that had flowed from the south vent (left) from 7:30-7:50 a.m. HST. The north vent (right) had weak spattering in its vent. As of 9:00 a.m. HST, episode 12 of this eruption has not started but this minor activity suggests that it may soon. USGS photo by K. Lynn.

A USGS Hawaiian Volcano Observatory geologist collected of molten sample of lava in the eastern portion of Halema‘uma‘u crater the morning of March 4, 2025. In this portion of the crater, far from the eruptive vents, lava has slowly oozed out in recent days as residue from earlier episodes. All samples are collected in coordination with and after receiving permission from Hawai‘i Volcanoes National Park. Analysis of the sample will provide information for ongoing eruption hazard assessment. USGS photo by M. Patrick.

Episode 12 of the ongoing Halemaʻumaʻu eruption began a fountaining phase at 2 p.m. HST on March 4.  Several small lava flows came from the south vent during the morning and early afternoon of March 4. At 2:00 p.m. HST, fountaining began at the north vent. Fountains from the north vent were within the north cone and about 20-30 feet (5-10 meters) high at the start. By 2:20 p.m. HST fountains were reaching 60-80 feet (20-25 m). USGS webcam image.