September 17, 2025 – Lava rises within the north vent during gas pistoning activity

Cyclic rising and falling of the lava pond at the Halema‘uma‘u north vent was indicative of ongoing gas pistoning during the morning of September 17. Seismometers have tracked this gas pistoning since shortly after the end of Kīlauea summit eruptive episode 32 on September 2, but only in the past couple days has lava risen high enough for the cycles to be visible. This activity was observed by Hawaiian Volcano Observatory scientists on the western crater rim, which afforded an excellent view of the north vent. USGS photo by C. Cauley.