Halemaʻumaʻu eruption · episode 31 of 55
Kīlauea episode 31
Episode 31 of Kīlauea's Halemaʻumaʻu eruption began at 2:04 p.m. HST on August 22, 2025 and ended at 2:52 a.m. HST on August 23, 2025. USGS gives the duration as 13 hours. HVO's Uēkahuna tiltmeter (UWD) recorded about 22 microradians of deflation during the episode. HVO notes: North and south vents active; north vent dominant and inclined. Intermediate vents also active.
Episode 31 at a glance
- Start (HST)
- August 22, 2025, 2:04 p.m.USGS timeline
- End (HST)
- August 23, 2025, 2:52 a.m.USGS timeline
- Duration
- 13 hoursUSGS timeline
- UWD tilt (deflation)
- about 22 microradiansHVO notice
- Max fountain height
- about 88 mUSGS timeline
- Lava erupted
- about 7.6 million m³USGS timeline
- Pause that followed
- 10 daysUSGS timeline
In HVO's words
The sentences these figures come from, quoted from USGS Hawaiian Volcano Observatory notices.
“The Uēkahuna tiltmeter (UWD) recorded about 22 microradians of deflationary tilt during episode 31.”
HVO notices about episode 31
- Volcano Activity Notice · Aug 22, 2025, 2:16 p.m. HST
- Volcano Activity Notice · Aug 23, 2025, 3:23 a.m. HST
- Daily Update · Aug 27, 2025, 9:00 a.m. HST
Daily updates: USGS Kīlauea volcano updates. Full table: USGS Timeline of Eruptive Episodes.
Times are Hawaiʻi-Aleutian Standard Time (HST). Start and pause times, durations, fountain heights and lava volumes come from the USGS Hawaiian Volcano Observatory's Timeline of Eruptive Episodes; tilt figures and episodes not yet in that table are quoted from HVO notices. USGS describes these as unreviewed, preliminary estimates that are subject to revision. Durations for episodes 17 and earlier may include precursory activity, and HVO rounds durations to the nearest hour, half-hour or day. A blank cell means HVO hasn't published that figure in a form we could read; we don't estimate it.
Credit: U.S. Geological Survey. This archive is generated automatically and is not an official USGS product.