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).
(The summit collapse was M 5.3 again. The livestream is still ailing, but even so it captured rockfalls, camera shake, and the earthquake’s progression from far to near in the field of view.)
Lava delta is up to 690 acres, by the way. “Tiny no-longer-island” is next to the c in “former coastline.”
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.
And a reminder of what it used to be like…
July 11, 2018, 6:00 pm – Kilauea's east rift zone overflight: The large channelized flow to the west of Kapoho Crater,…
Posted by Extreme Exposure Fine Art Gallery on Thursday, July 12, 2018
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.]
The level of Fissure 8’s lava river was low above Pohoiki Rd in the hours before the summit collapse. USGSVolcanoes posted at 7:17pm today that they observed an increase in Fissure 8 activity following the 2:42pm summit collapse (mag 5.3, here’s video), raising its level again. But there were no overflows, apart from some “small channel breaches south of the 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
— Hot Seat Hawai'i (@HotSeatHawaii) July 12, 2018
USGS field teams reported “no visible activity” at Fissure 22 or any other fissures besides 8.
Today, USGS also posted a 3-month timelapse of Halema’uma’u from the HVO panorama cam, April 14-July 11:
This is another busy news day.
There was a lot of good info in the Thursday conference call with members of the media. BigIslandVideoNews posted a recording of most of it:
Full audio archived here.
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:
On HVO website: Volcanic Hazard at the Summit of Kīlauea Update [summary: “This document is a guide for understanding current activity and hazard at and around the summit of Kīlauea Volcano. Here, we summarize activity from late April through the present, detail possible future outcomes, and review hazards associated with these outcomes.”] Presumably it’s called an “update” because it supplements the June 26 “Frequently Asked Questions About Kīlauea Volcano’s Summit Earthquakes” FAQ. [EDIT: No, actually, it’s an update to the May 8th “Preliminary Analysis of Current Explosion Hazards at the Summit“]
This was the chief topic of Thursday’s Volcano Village meeting, led not by the National Park Service this time, but by Civil Defense Administrator Tal Magno.
Here’s the FULL video of the meeting. BigIslandVideoNews excerpted the most important part, HVO Scientist-in-Charge Tina Neal’s 4-minute talk: