Halemaʻumaʻu eruption · episode 28 of 55
Kīlauea episode 28
Episode 28 of Kīlauea's Halemaʻumaʻu eruption began at 4:10 a.m. HST on July 9, 2025 and ended at 1:20 p.m. HST the same day. USGS gives the duration as 9 hours. HVO's Uēkahuna tiltmeter (UWD) recorded 15 microradians of deflation during the episode. HVO notes: Only north vent active.
Episode 28 at a glance
- Start (HST)
- July 9, 2025, 4:10 a.m.USGS timeline
- End (HST)
- July 9, 2025, 1:20 p.m.USGS timeline
- Duration
- 9 hoursUSGS timeline
- UWD tilt (deflation)
- 15 microradiansHVO notice
- Max fountain height
- about 321 mUSGS timeline
- Lava erupted
- about 5.2 million m³USGS timeline
- Pause that followed
- 11 daysUSGS timeline
In HVO's words
The sentences these figures come from, quoted from USGS Hawaiian Volcano Observatory notices.
“Lava fountaining associated with episode 28 resulted in 15 microradians of deflation on the UWD tiltmeter.”
HVO notices about episode 28
- Volcano Activity Notice · Jul 9, 2025, 5:11 a.m. HST
- Volcano Activity Notice · Jul 9, 2025, 1:49 p.m. HST
- Daily Update · Jul 18, 2025, 9:15 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.