June 25: Ahulanui Ponds May Be Next

Today’s Eruption Summary

Fissure 8 is status quo. Today’s HVO Kiluaea status report says its cone is now 180feet tall. Its flow front has broadened southwards, widening to two miles, moving south on shore as well as continuing to expand offshore (lava delta acreage: ~405). The main channel/ocean entry remains on the southern side of the front, with minor entries in a 1-kilometer zone.

The lava Fissure 22 is weakly active; no activity observed at 16/18.

USGS: “This animated gif shows the fissure 8 tephra (cinder and spatter) cone morphology changes between June 15 and 24, 2018. During this time a shoulder grew on the channel side of the cone as the vent shifted from being two distinct fountains to three, then to a single source of voluminous roiling. The cone height is about 47 m (154 ft) from the hardened lava surface on which it was built.” Note: This isn’t a webcam but a temporary camera they set up; they have to download pictures manually. (Full-sized)

According to Mike Zoeller (UHI) at today’s 11AM conference call, the lava delta is advancing at less than 50m/day; it was 200/day a week ago.  The southern edge of the flow is a kilometer from Ahalanui Beach Park. Over the weekend, he observed top lava speeds of 25kph (15.5mph); Leslie Gordon (USGS) saw it max out at 35kph (21.75mph) last Friday night.

USGS: “USGS Hawaiian Volcano Observatory geology field crews maintain watch over the eruptive activity in the lower East Rift Zone and at Kīlauea’s summit. Here, a geologist documents the behavior of lava as it exits the Fissure 8 cone. Lava enters the upper channel traveling as fast as 30 km/hour (18 mi/hour).” (Full-sized)

After yesterday’s collapse explosion at 4:12, seismicity dropped from a high of 25-35 quakes an hour down to less than 10,  but had started to creep up again and was averaging 30 by dawn. On the livestream, I observed clouds of ash/dust in the crater’s interior at various times during the day. Today’s collapse explosion occurred at 5:03pm, equivalent of a 5.3, ash-poor plume rising less than 2000 feet.

Jun 24: chasing rainbows and lava with Mick Kalber. He was checking on a lava spillover uncomfortably near his house!  (Helicopter noise)

Reminder: HVO downgraded Kilauea’s aviation alert to ORANGE last night, because ash explosions have rarely risen above 10,000 feet since May.

11AM USGS Conference Call

Actually, Mike Zoellner of UHI is spelling USGS crew this week.

BigIslandVideoNews has edited down the 20 minute conference call (here’s my transcript) to 3 minutes:

June 25 Lava Flow Map
USGS lava flow map as of 2pm, June 25, 2018. (Full-sized)

6,164 acres covered by lava (according to Civil Defense this afternoon).

USGS on Social Media

Additional info from FB:

“On June 18, Hawaiian Volcano Observatory staff said a sad goodbye to a GPS instrument that had faithfully recorded over 310 feet (95 meters) of downward motion of the floor of Kilauea caldera before losing radio contact. The GPS instrument, called NPIT, first started moving downward in early May at the onset of subsidence at Kilauea’s summit. However on June 8, NPIT’s motion picked up dramatically. This was when a portion of the caldera floor north of Halema’uma’u, where NPIT was located, began to slump into the crater. Over the next ten days NPIT GPS recorded down-dropping of 20-25 feet (6-8 meters) with each summit explosion event, which have been occurring almost every day. This, together with earlier displacements, added up to a position change of 310 feet down, 180 feet south, and 16 feet east (95 m, 55 m, and 5 m respectively).

These data provide unique insight into the crater collapse process, showing us that it is occurring as a series of steps instead of as continuous motion. Drone and helicopter views confirm that NPIT is still intact and likely still recording data. Unfortunately, the large motions have now resulted in a misalignment of the radio shot between the instrument and the observatory, cutting off communication and therefore data flow from the GPS station.

At about the same time that we lost the ability to contact NPIT, HVO staff completed work to add telemetry to two temporary GPS stations on the caldera floor. These two stations, called CALS and VO46, are not located on actively slumping portions of the caldera floor and therefore do not show the dramatic downward motion that NPIT did. However, they reveal that even portions of the caldera floor away from active slumping are moving downward very quickly; by as much as 3.3 feet/day (1.0 meters/day) at station CALS. Recent data from these new stations can now be viewed on the HVO website at https://volcanoes.usgs.gov/volcanoes/kilauea/monitoring_deformation.html

Q: Caldera subsided about 60m since May? 1 m/day? Proportional to erupted lava?
USGSVolcanoes:  The subsidence varies hugely over the caldera floor. The bottom of Halema`uma`u has subsided by over 300 meters, while other parts of the caldera floor (at the base of the caldera wall near Volcano House) the subsidence has been much less (a meter or less). The volume of the subsidence so far resembles that of the erupted volume, although we’re still working on calculating both quantities.

Q: Has this changed your mind about possibility of caldera collapse?
USGSVolcanoesNot really. The primary action is close in to Halema`uma`u, where the walls and rim are slumping inward as the crater deepens. That isn’t to say that major subsidence of the caldera is not occurring — obviously it is (the data show that very clearly). But we do not see evidence suggesting a potential caldera-wide collapse at this point, where the entire caldera would downdrop in a massive event. But part of the reason we installed these new stations was to continue tracking the activity, to look for changes that might indicate some new process occurring.

Q: Is collapse moving towards Volcano House or miltary camp?
USGSVolcanoes: The crater is growing, and the motion is increasing in the direction towards Volcano House, but satellite radar data suggest that the significant motion stops well short of the caldera floor beneath Volcano House.

[capture of today’s collapse on HVO Livestream]

Q: How much has caldera rim moved where Jaggar Museum is?
USGSVolcanoes: So far, the caldera rim hasn’t moved that much, despite the large subsidence and crater enlargement occurring on the caldera floor right beneath the museum. We have a GPS station located nearby (UWEV, also on the HVO Kilauea deformation website) which helps us to monitor the stability of the rim.

Q: Could some of the earthquakes be from blocks falling into the magma chamber?
USGSVolcanoes: We don’t believe that blocks are actually falling into the magma chamber (that type of void space probably doesn’t exist in large amounts, although we can’t be certain), but rather the downward slumping of the caldera floor near Halema`uma`u as a single unit. This is why the associated seismic events (the near-daily M5 earthquakes) are so strange in terms of the energy they radiate. The earthquakes appear to have a lot in common with other collapse-style seismicity in areas where there is no magma present.

Q: Are the explosions causing those 20-25 foot drops, or part of them? What’s the mechanism for the timing?
USGSVolcanoes: The M5+ events that occur nearly each day are associated with the 20-25-foot drops. The small explosions aren’t really “causing” those, but rather it’s one system that has many manifestations. The largest earthquakes are collapse-style events as the caldera settles, and that’s when a lot of the blocks around Halema`uma`u move. As for the timing, we don’t have a great handle on why they are so repeatable. We suspect that it reflects the relatively constant deflation rate due to magma withdrawal from the summit, which means the settling of the caldera floor occurs at a constant rate, and stress builds up at a steady rate. But this will need to be tested and refined with models that incorporate a variety of data.

USGS: “This panorama of Kīlauea’s summit caldera was made about 10 a.m. HST from the KEANAKANOI overlook on the south side of the caldera. Halema‘uma‘u is visible steaming to the left, and the ongoing ground cracking is visible in the center of the image.” (Full-sized)

Q: How much southward has south of island moved since May?
USGSVolcanoes: Typically, the south flank moves towards the ocean at a rate of a few millimeters per month. Since the M6.9 earthquake, there was a little bit of seaward motion (about 2 cm over a few weeks) as the flank adjusted due to the earthquake (we call this “postseismic deformation,” and it is a common process after all strong earthquakes), but for the last month there has been very little motion of the station towards the sea. In other words, the flank is behaving normally now that the postseismic motion has ceased. We’ve attached the plot from one of the GPS sites near Kaena Point as an example of what is occurring — the plot shows north-south deformation since May 5 (a downward trends mean that the station is moving south, towards the sea).

posted in a comment on Facebook (no way to direct link to comments)

Q: Fissure 8’s cone is 154ft? 
USGSVolcanoes: Yes, that’s current. The cone may be closer to 200 feet above the original ground surface, but it is built on some meters of lava that hardened prior to the cone’s formation.

[I asked for clarification, since today’s and yesterday’s HVO Kilauea Status Report say 180′, up from 170′ and 164′ in USGS posts a week or two ago.]

Q: Can we have new data for Kilauea Floor GPS now that NPIT is gone?
USGSVolcanoes: We have two temporary GPS stations on the caldera floor, but scientists have to visit them in order to download data. We will be updating our deformation monitoring webpage later today!

USGS: “View of the fissure 8 cone and fountain from the end of Luana Street in Leilani Estates. Photo taken at 12:20 p.m.” (Full-sized)

Q: Any news on the new cracks between fissure 9 and 10 a week ago, uprift of Fissure 8? Property owner says they’re getting bigger.
USGS: We’ve had ground crews monitoring those cracks closely by taking repeat measurements of width, testing for SO2 and other gases, and checking temperature with a thermal camera. We will continue to do so and alert Civil Defense and the homeowner if there are any concerning changes.

Q: What started this chain of events?
USGSIt all began with the breakage of some sort of valve near Pu`u `O`o — the site of the eruption for the prior 35 years. That barrier was preventing magma from traveling form the summit all the way down the rift zone. We tried to summarize this information in a news post on the HVO website — check outhttps://volcanoes.usgs.gov/obse…/hvo/hvo_news_archive.html and go to the second article in the list, posted on May 24.
USGS [correcting someone]:  Actually, current eruption started on May 3, the day before the May 4 M6.9 earthquake! The magma feeding the eruption started it’s motion downrift on April 30. The quake actually was caused by the magma intrusion into the East Rift Zone — it pushed on the south flank and added stress to the south flank fault, which then ruptured. Kilauea’s magmatic and tectonic systems have a very complex interrelationship. As for what broke the Pu`u `O`o valve, we’re not really sure (that will be the focus of much research once this event is over). It appears to have been the weak link in the system this time.
[Cont’d] The chemistry was evolving by May 18, but the article was specifically referring to the fact that the rift zone stopped widening at that time. This implies that the magma conduit from the summit stabilized, and magma was no longer forcing open the lower East Rift Zone. The conduit had become established.

USGS: “Early morning view of the open lava channel during helicopter overflight of the lower East Rift Zone.” (Full-sized)

Q: Just how big is this eruption? Was that 6.9 earthquake like a release valve; will the summit totally depressurize? Could the caldera drop?
USGS: This is a very large eruption. It’s bigger than 1955 and 1960, and might be approaching the size of the 1840 eruption. It’s basically erupted in less than 2 months what would have taken Pu`u `O`o about 2 years to put out. The M6.9 event might have opened some space within the volcano and allowed for easier flow of magma from the summit to the eruption site (we’re still examining that possibility). As for the summit, we don’t believe it will completely depressurize, because magma has a pretty high viscosity, and so has some strength to it — it doesn’t behave like water, even though it looks like it might given the river of molten material flowing out of fissure 8. At some point, the pressure will be low enough that the flow to the eruptive vent can no longer be sustained. And we don’t see a reason that the caldera would founder in a single event. In fact, what we are seeing now argues for just the opposite — that the caldera floor around Halema`uma`u is dropping as a series of discrete events that are likely to continue as long as the depressurization persists.

Q: Haleakala is dormant not dead?
USGS: Exactly. Haleakala last erupted several hundred years ago. More information is at https://volcanoes.usgs.gov/volcanoes/haleakala/

[Discussion about various cones collapsing, Pu’u O’o floor collapse] was that before or after the 6.9 earthquake?
USGS: This was before the M6.9. The floor collapse was almost instantaneous with the onset of the dike intrusion on April 30. And this sort of thing has happened before (although not to this degree)… Check it out:

Q: Could new fissures open?
USGS: We don’t see a reason that new fissures would form, although that can’t be ruled out. The formation of new fissures should be preceded by some other changes — more seismicity and deformation in the lower East Rift Zone, for example. But as long as Fissure 8 continues to pump out lava, it seems to be able to handle the bulk of the flow from the summit region.

Q: I imagine lava is heavy— can you feel the ground vibrating or shaking near the lava flow?
USGS: We don’t really feel anything particularly anomalous close to the vent, aside from the heat. The sound is more noticeable — the “whooshing” from the spattering events can be quite loud.

Uploaded today:

HNN’s Mileka Lincoln reposted it, but as usual I prefer to post the original.


From other official channels

Here’s the daily Hawaii Civil Defense alerts, since I haven’t linked to them in a while: [ 6AM | 4PM  ] They repeat those just about word-for-word each day, adding any scheduled community meeting.

June 21 overflight from DLNR:

This is a few days old, but it gets up close and personal with Fissure 8 at 16:00, circling around it looking into it, and at the end they take a spin around Pu’u O’o.

From Local News Outlets

Moment of ALOHA
From Social Media

Yep, it’s a 5.3. 5.5 is when the cat gets up and stalks off in a huff. (Or at least that was true for my previous cat; the current one has not yet been calibrated):

This was Yesterdays 5.4 earthquake at Jeff Judd’s house in the Volcano golf course…Check out the trees outside shaking around in the background as well as action in the house…Mahalo Judd Ohana and the chillest cat on the planet Kazu!!

Posted by EpicLava on Monday, June 25, 2018


Posted by EpicLava on Monday, June 25, 2018