Status quo. No significant overflows today from Fissure 8’s lava river. USGS morning overflight put the southern margin of the coastal flow field at 500 m from boat ramp at Isaac Hale Park. In other words, not much movement in that direction.
Summit collapse occurred while I was writing up this post, as expected: 8:54 pm HST, back to an energy equivalent of M5.3 on reviewing readings, they upped this one to 5.5! Let’s see whether that results in an early-morning Fissure 8 surge tomorrow, er, today, Monday.
When the National Park opens again, they’re going to have a new— or rather, very old— landmark that I confess I’m rather excited about, although it’s not quite as photogenic as a lava lake. Mark Twain would’ve seen this during his visit in 1866:
As we approach the 3-month mark, the USGS is beginning to supplement its daily reports on the eruption itself with recognition of scientists and support crew who have been working 24/7 to monitor, collect scientific data and inform civil defense and the public since this eruption began. The drone crew worked overtime last night after being grounded by weather then night before:
Two maps today, one assembled from yesterday morning’s overflights and one from 2 o’clock this afternoon:
Status quo. Fissure 8’s lava river continues inexorably to the Ahalanui Beach area. At the coast, the flow has nearly stalled in its southern expansion, but according to Civil Defense has crept within ¼ mile of Pohoiki boat ramp.
July 21, 2018. USGS: “This aerial view, looking to the southwest, shows the most vigorous ocean entry of the fissure 8 flow, which is located a few hundred meters (yards) northeast of the southern flow margin.” (Full-sized)North of the main ocean entry, a few small pahoehoe lobes are still dribbling into the sea along the rest of the delta.
Today’s summit collapse event occurred at 9:43 am, registering as M5.4 for a change. It was preceded by widespread rockfalls about 3 minutes earlier, which I included in the video capture (jittery livestream signal notwithstanding):
The Lower East Rift Zone eruption continues as per usual. USGS reported during today’s morning overflight that “the channel was incandescent its entire length from vent to ocean entry.” There’s a main ocean entry a few hundred meters NE of the southern flow border with smaller pahoehoe flows on either side. The southern margin doesn’t seem to have advanced much from yesterday.
No other fissures are active, and I already covered yesterday’s 4:33 HST collapse event. I’m betting the next one will be after dark.
Janet Babb, Kīlauea Update: Good afternoon, everyone.
On the Lower East Rift Zone, Fissure 8 is still active. It continues to erupt lava into the perched channel that extends down on the west side of Kapoho Crater and feeds lava into the ocean. This morning, the main ocean entry was a little bit west of Ahalanui, with the flow margin about 500 meters, or 0.3 mile, from the Pohoiki boat ramp. There’s still some weak ocean entry points to the north of this main entry over near the Kapoho Bay lobe of lava where there were some weak, wispy plumes there. The flow front along the ocean, along the coast is still about 6 kilometers wide or 3.7 miles wide. On the Lower East Rift Zone, the sulfur dioxide emissions remain high, and the ocean entry hazards include the laze plume, as well as the possible hydrovolcanic explosions, what we referred to on Monday as “littoral explosions.” Hydrovolcanic is a little more intuitive word to explain the lava-seawater interaction.
Up at the summit, as we speak earthquakes are occurring at a rate of about 25-30 per hour as the volcano builds up to the next collapse event [this phonecall at 1 pm, collapse came at 4:33 pm.] The previous collapse event weas at 1:28 am July 18, so it’s been about 36 hours. We are within that time interval where we typically see these collapses occur. At the summit, the sulfur dioxide emissions are low. We’ll be posting some new photos and a new map shortly after this media call. That’s all.
As per usual. Fissure 8 continues to feed the lava channel down to the ocean, where the southern margin of the flow was 500 m from Isaac Hale Park this morning. Lava levels in the channel this morning were low, with the previous collapse event coming at 1:28 am the day before.
Today’s summit collapse event occurred at 4:33 pm.
Q: [Is Cape Kumakahi still the easternmost point of the island?] USGS: The area off Kapoho has a paltry supply of lava now – unless significant lava returns, the eastward advancement may cease.
Q: [Has there been any change in temperature of lava, now that it’s crusting over and/or not a fluid channel all the way to the ocean? Any sign eruption is ending?] USGS: No, the temperature remains the same. Other factors are probably responsible for the crusting – blockages, flow velocity, precipitation, etc. Sometimes the channels remain fluid, and sometimes the surface can crust over – but that doesn’t mean there isn’t lava moving beneath the crust… No, no signs that the eruption is ending yet.
Q: [Someone asking about webcams and livestreams] USGS: We weren’t able to adjust the bandwidth on the cam from HVO, but we did add the stream from the northeast caldera, which uses a different (and still challenged) connection.
Q: [Cinder cone is 120 feet now? Was 180; has it collapsed?] USGS: Some settling has occurred, and some of the more precarious bits have probably fallen in or down the slopes. [Same basic question, different day] USGS: Yes it has succumbed to thermal erosion, collapse, and settling. There have been no sustained fountains depositing material on its outer slopes for several weeks, so there has been no additional accumulation of tephra.
Vladimir Vysotsky on FB: USGS Volcanoes: you keep characterizing this as a “perched channel”. I wonder if that is how lava tubes form – a channel builds the foundation and walls around itself, then crusts over while still flowing inside, and eventually forms a tube when the lava finally drains. Is that a correct assumption?
USGS Volcanoes: That is a very accurate description of lava tube formation! ][…] Hereʻs a video from Hawai’i Volcanoes National Park describing what you d[id] with video footage to accompany for visual reference. https://www.nps.gov/media/video/view.htm...
Q: [Is Fissure 8 how Diamond Head formed?] USGS: – Diamond Head is a tuff cone that erupted through water. It is also considered “rejuvenation stage” volcanism. The eruption that formed it occurred after the Koʻolau Volcano (from where it erupted) had been dormant for about 2 million years! http://volcano.oregonstate.edu/post-erosional-rejuvenation
Q: [How long will this go? How will it end? Does a lava flow normally start slowing down and then stop?] USGS: This could go on for any number of days, honestly. Typically these things don’t just turn off and stay turned off. We expect that activity in Fissure 8 will wane, then stop and start again (perhaps at other fissures). However, the eruption won’t stop all together until the pressure driving the magma out of the ground has been relieved.
Q: [How deep is lava channel?] USGS: We have tried to calculate depths based upon lava-flow observations within the channel and known depths of dormant channels on other locations in the Hawaiian islands. The channel is meters in depth, but likely not more than 10. Depth varies throughout its length as well.
[In discussion that Fissure 8 is not a volcano— it’s a vent on Kilauea’s flank just like Puʻu ʻŌʻō was, with magma being piped down from Kīlauea’s magma storage system— someone brought up Lō‘ihi, which IS a new volcano (or seamount) off SE coast of Big Island, still underwater.]
Q: [Is the summit caldera sitting on the magma chamber?] USGS: The subsidence area within the caldera essentially overlies the area of the shallow magma storage region that fed the lava lake in Halemaʻumaʻu. So, yes. Q: [Could the floor collapse into the chamber? What would happen then?] USGS: Technically speaking, the floor, and everything that was between it and the top of the chamber, is collapsing into it. Youʻre seeing the outcome – pressure drops and collapse events that manifest as M5.3 earthquakes.
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.
Fissure 8 surged after last night’s summit collapse and sent brief-lived overflows towards Nohea Street and on both sides of the channel further down. Civil Defense reported an unspecified number of structures lost; Janet Snyder of the Mayor’s office said one in the mandatory evacuation zone of Leilani Estates.
Other fissures remain quiet.
Past Kapoho Crater, a pulse of a’a made its way to the ocean, overriding the existing channelized flow on the south side of the delta. Ooze-outs continue here and there along the edge of the delta.
And we’re back to routine, except that Fissure 8’s providing a minor puzzle to keep HVO busy. Yesterday it didn’t exhibit the surge behavior that’s been typical after summit collapses for the week or so. Today, nowhere near the time of a collapse event, “surging was noted at the Fissure 8 cone during the [morning] overflight but had stopped by the time ground crews arrived to verify it.” Otherwise, the channel’s lava level was low this morning. No other were fissures active.
Both the strong southern ocean entry and weak “ooze-outs” north along the edge of the lava delta continue. Onshore, the southern margin of the flow front was reported to be half a mile from the Pohoiki boat ramp this morning. Unfortunately, that flow edge has stalled but not stopped, and a DLNR official warned Isaac Hale Park is still within its sights.
We’re still awaiting the next summit collapse, which looks like it’s going to thwart HVO’s new “Northeast Caldera Rim” livestream by happening at night.
The split-second info card at the end says the floor of Halemaʻumaʻu Crater has dropped 450 m (1480 ft). Prior to the current eruption, it was 85 m (~280 feet) deep. So it’s about 1760 feet deep now. (World Trade Center One is 1776.)
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.