Here’s a transcript of this week’s presentation from HVO Deputy-Scientist-in-Charge Steve Brantley at the Tuesday Pahoa Community Meeting.
I’m going to start with a broad overview of the eruption so far. We’re 80 days into the eruption [since the floor dropped on Puʻu ʻŌʻō, I think] about now, so I want to provide a little bit of context, in terms of similar activity or un-similar activity in the past 200 years. And then we’ll do a quick summary of what’s happened in the past week.
The big news today was a lava tour boat getting pelted by lava chunks from an ocean entry explosion, resulting in burns, bruises, and one broken leg. Next to that, the science of this eruption seems a bit trivial. But this blog is primarily oriented towards the latter, so let’s get volcanology news out of the way first.
The Italian Space Agency released a new CosmoSkyMed radar scan of Kīlauea’s summit. Let’s hope this really is the new northern extent of Halemaʻumaʻu:
This morning, over 24 hours after the previous summit collapse, the lava channel below Fissure 8 was full but not overflowing. Even after today’s 11:42am summit collapse, there was no observed surge— “Nothing notable in the way of overflows.” Last night’s field crews heard Fissure 22 grumbling to itself, but saw no visible signs of renewed activity.
According to Civil Defense this afternoon, the southern edge of the main lava flow has stalled 1 km from Isaac Hale Park / Pohoiki boat ramp. Just north of there, the new ocean entry at Ahalanui is vigorous and dangerous. That’s where @hotseathawaii filmed an offshore explosion four days ago. There were more explosions this morning, “with at least one being quite strong” (USGS).
Kilauea’s double eruption continues as usual. Fissure 8’s lava river is still sending lava mostly to the southern ocean entry near Ahalanui, following the diverted channel on the west side of Kapoho Crater. The southern margin of the lava flow along the coast has slowed its southward advance, possibly giving Pohoiki/Isaac Hale Park a respite. At 7pm HST, HVO said it was “around half a mile away.”
The tiny island that formed Friday is now a tiny peninsula, joined to shore by a neck of lava or possibly just black sand. Lava continues to ooze into the ocean here and there along the broad front of 6 km (3.7mi) lava delta. Recent HVO Kilauea status alerts have warned that this delta has built out 0.5 miles from the former coastline, and is resting on “unconsolidated lava fragments and sand,” which can give way.
Following this morning’s 3:26 am collapse event (M5.2) at Kilauea’s summit, a pulse of lava came down the rift zone to Fissure 8. This caused an early-morning, temporary overflow to the ESE which did not extend beyond the boundaries of earlier flows. (This spillover was very visible during a 6:30am @hotseathawaii livestream overflight). No other vents show any activity.
Sadly, yesterday afternoon was the end of Kua O Ka La Charter School and Ahalanui Warm Ponds. The flow that diverted west of Kapoho Crater created a channelized a’a flow all the way to the ocean. There is now a strong ocean entry at what used to be Ahalanui Beach Park. There are still multiple “ooze-outs” along the northern lava flow front spanning former Kapoho Bay— it’s now 6 km, 3.7 miles across— “despite no visible surface connection to the fissure 8 channel.”
[Below: USGS 6am overflight, July 12: Fissure 8 perched lava channel, new diverted channel around Kapoho Crater, Ahalanui ocean entry.]
Speaking of the ocean entry, Bruce Omori of @HotSeatHawaii captured a startling offshore laze/steam/lava explosion just offshore:
Huge underwater explosion from Hawaii eruption. Bruce & Mick don't quite see it and I think the explanation for that is that the GoPro shoots such a wide angle that even though it looks like it is right in front of them, it was likely below their line of sight. pic.twitter.com/otJxmh9TAg
Mike Zoellner, geologist, Center for the Study of Active Volcanoes, UHI
Transcript – July 11 Eruption Update
Janet Babb, USGS: On the Lower East Rift Zone, Fissure 8 continues to erupt, and overnight the channelized flow that was diverted from the main channel that went west of Kapoho Crater advanced to the ocean, and, unfortunately, in its path, it destroyed the Kua O Ko La Charter School and the Ahalanui Beach Park area. And there’s now a new, very robust ocean entry plume near the Ahalanui Beach Park area. So in all, the flow front at the ocean now is about 3.7 miles wide.
In this morning’s overflight, there were no other fissures that appeared to be active.
At the summit, following yesterday’s early morning collapse/explosion that released energy equivalent to a magnitude 5.3 earthquake, the earthquakes have resumed— there was a period of quiet, but the earthquakes have resumed and currently the summit area is experiencing about 25-30 earthquakes per hour. This pattern is expected to continue.
As far as gas emissions at the summit, the gas emissions remain low, and on the Lower East Rift Zone, the gas emissions remain high. And with that, of course, the problems with vog continue with those high emissions.
Informing the public without panicking them about an extremely unlikely but life-threatening hazard is tricky. So it’s taken the USGS a while to release this document which they’ve been promising the residents of Volcano: