July 8: Ahalanui Warm Pond, School Under Lava Threat

Today’s Eruption Summary

The LERZ continues as usual, although there are tantalizing hints that change could be on the way:

July 8, 2018. USGS: “Fissure 8 (lower right) and open lava channel leading to the northeast. Geologists noted small lava-level fluctuations in the open channel overnight, which indicates intermittent variations in lava discharge from fissure 8. An increase in lava levels was noted about 1.5 hours after the collapse-explosion event at the volcano’s summit at 02:55 a.m. HST. Evidence of a couple of recent, short-lived channel overflows were observed early this morning, but they had not reached the edge of the flow field. The small steam plumes in distance mark locations of fissures that erupted in early May at the beginning of the ongoing eruption.” (Full-sized)

Fissure 8 gushes within its large cone, Fissure 22 continues to spatter weakly. The open lava channel from Fissure 8 now ends about 2km (1.2 mi) from the coast:

July 8, 2018. USGS: ” View of the partially filled Kapoho Crater (center) and the open lava channel where it makes a 90-degree turn around the crater. The open channel no longer directly enters the ocean. Lava flows freely through the channel only to the southern edge of Kapoho Crater (left side of image). Clearly, lava moves into and through the molten core of the thick ‘a‘ā flow across a broad area from both the sides and end of the channel.” (Full-sized)

From the end of the channel, the lava dives under the crust of the slightly older flows that buried Kapoho Bay. It emerges again along a very broad ocean entry:

July 18,2018. USGS: “Multiple ocean entries were active this early morning, each contributing to the prominent “laze” plume above the area. Lava moves from the open channel through the molten core of the broad ‘a‘ā flow field to the ocean. Kapoho Crater is at middle right of photo.” (Full-sized)

According to USGS/HVO, the ocean entry is “primarily along the northern section,” as it has been for the past few weeks. However, to judge by today’s @hotseasthawaii overflight, there’s notable ocean entries to the south as well. Besides the lava that reaches the ocean, USGS reported lava “oozing out” to the north and southwest of the main a’a field just inland, as one can see on Friday’s thermal map. A few Kapoho Beach Lots houses are hanging on, threatened by the northern “ooze-out.” The southwestern “ooze-out” — several local photographers have reported an unconfirmed  “southern lobe” lava flow— is within a few hundred yards of Ahalanai Warm Pond and Kua O Ka La Charter School:

Screencap from early morning July 8 HotseatHawaii overflight. Ahalanui Warm Pond is just at the end of that straight stretch of Hwy 137, and the school is the light-colored patch just to the right of it. (Full-sized)

The most recent summit collapse event occurred at 2:55am HST, July 8, with an energy release of M5.4.

Italy’s Cosmo-Skymed satellite sent down another radar image of Kilauea caldera today:

July 8, 2018. USGS: “This animated GIF shows a sequence of radar amplitude images that were acquired by the Agenzia Spaziale Italiana CosmoSkyMed satellite system. The images illustrate changes to the caldera area of Kīlauea Volcano that occurred between May 5 and July 8 at about 6:00 a.m. HST. […] The most recent radar scene, from July 8, shows continued motion along cracks over a broader area of the caldera floor, extending east of Halema’uma’u (these cracks are the scarps seen in recent photographs from the Keanakākoʻi overlook area).” (Full-sized)
Mick Kalber overflight video

I keep throwing various names/handles around. Let me recap, since the names have multiplied, although the people haven’t.

Mick Kalber is a videographer (company: Tropical Visions Video) who’s been documenting Kilauea eruptions on Vimeo for years, chartering flights from Paradise Helicopters (who presumably give him a discount). His friend Bruce Omori is a photographer who posts images on his “Extreme Exposure Fine Art Gallery” on Facebook. They record notes about their flights on their Hawaii Lava Update Blog. Recently, they’ve also started livestreaming their flights —I think from a phone camera— at @Hotseathawaii on Twitter. So that’s different kinds of footage from the same chaps, whose near-daily overflights supplement info from official channels.

Got it? Got it. Here’s Mick’s video clips from this morning, and his notes.  This video still shows the school and Warm Pond: 

From Local News Outlets
USGS Q&A on Social Media

Q: Why did Halemaumau lava lake overflow when this started? Besides 6.9 eq.
USGS: Actually, the M6.9 event did not trigger this. Rather, the earthquake was a consequence of the intrusion of magma into the East Rift Zone. Starting in March, we saw pressure building beneath Pu`u `O`o (probably because the lava eruption was slowing, like the hose was kinked). The pressure buildup eventually propagated back to the summit, causing the lava lake to rise and overflow onto the floor of Halema`uma`u in late April. On April 30, the pressure finally caused a barrier beneath Pu`u `O`o to break, and magma began flowing downrift, eventually erupting in the Leilani Estates area. The spreading of the rift zone in response to the intrusion of magma put pressure on the large fault that underlies Kilauea’s south flank, and it moved in a large M6.9 earthquake. We’ve actually seen earthquakes like this before, after other East Rift Zone magma intrusions. Typically they are on the order of M5, but this is a much larger event, so the earthquake was also larger.

July 8, 2018. Another view of Kapoho posted on @USGVolcanoes Twitter today. (Full-sized)

Q: MARCH! You started seeing signs in MARCH? But the roads in Leilani started cracking in May! And no one got serious until they were prepared to close the park. I realize we learn as we go but no one saw this coming?
USGS: Yes, that’s when Pu`u `O`o started to inflate. Every other time that has happened (and it has happened often — for example, 1993, 1997, 1999, 2007, and 2011 to name a few or the more significant events), there was a new eruptive vent that formed in the near vicinity of Pu`u `O`o (within about 2 km). We expected something similar to happen this time as well, given the past patterns, and issued a formal information statement along these lines.
Trying to understand why it was the main East Rift Zone conduit that broke open instead of something shallower will be a major theme of future research when we have the time to examine all of the available data. As soon as the eruption began on the lower East Rift Zone and the summit began to deflate, it became clear that summit subsidence and small explosions were a possibility, and the Park and residents of the Volcano community were alerted. The extreme lowering of the lava lake is what prompted closure of the park.

Comment on most recent satellite image of summit (the animated gif showing week-by-week collapse): Does this mean this thing is getting ready for a big one or is it dying out?
USGS: What’s happening now is a big one. But if you mean big explosion, that remains unlikely. The radar animation demonstrates that the caldera continues to collapse, which means that the magmatic system is depressurizing. Large explosions are pretty hard to generate without a source of pressurization.

Q: We’re told magma has withdrawn from Halema’uma’u before and returned, but was there also a collapse like this? This seems different: magma won’t return, but the caldera will fall down.
USGS: The caldera collapse ~500 years ago was much larger than the current one, and lava still eventually came back. This is the way Kilauea works. The stream of magma into the bottom of the volcano is more or less continuous (there are some fluctuations). After an event like this, it might take some years to refill parts of the volcano that have drained, but once that happens, eruptions can begin again.

July 8, 2018. USGS: “Braided section of the lava channel located “downstream” between about 3.5 to 6 km (2.2 to 3.7 mi) from fissure 8 (upper right). The width of the two channels in the middle center is about 325 m (1,065 ft). View is toward the southwest.” (Full-sized)

Q: Based on past events, do we know how long, how big this collapse will be?
USGS: That’s a good question, and a tough one to answer, because we don”t have a direct record of the collapse that happened ~500 years ago (that was much larger, but would at least give us some ideas). There hasn’t been much deepening of late, because rubble infill is compensating for deepening of Halema`uma`u. Overall rates of broader subsidence (outside the collapsing area) at the summit seem down, but the collapse itself is occurring at a pretty constant rate, perhaps “catching up” to the subsurface volume loss.

Q: We know lava will return to the summit sooner or later— how about Pu’u O’o?
USGS: We suspect that Pu`u `O`o is probably done. By the time Kilauea’s magma system recharges, that vent will have been inactive for some time, and it seems hard to believe that it will be able to come back to life.

There’s been a few questions about a distant glow on the Kilauea KE cam.
USGS: We think that some of the glow you can see at night on the KE cam is from fissure 8 in the distance, not anything in the crater. [To more questions] USGS: The summit team has discussed it, and they think that it is well above the caldera rim. NPS is helping check on it, though.

Q [two different questions, one about possibility of pyroclastic surges— someone said “USGS reported a Kilauea pyroclastic surge could affect up to a 3 mile radius around the point of the surge”, while another reiterated that Kilauea isn’t the same kind of volcano as Krakatoa, St. Helens, etc that produce major pyroclastic explosions. Second question was on the impact of 40,000 tons/day SO2 from LERZ eruption.]
USGS: Good information in all the replies! Surges have happened at Kilauea in the past — most recently in 1790 (this is the event that devastated part of Keoua’s army). They happen when an ash plume collapses under its own weight, so it would require a significant explosive eruption. At this point, we can’t discount such an event, but we do consider it very unlikely because magma continues to drain from the subsurface. Before any such event we expect to see significant changes in deformation, seismicity, gas emissions, and other indicators that would allow such an event to be forecast. As for the 40,000 t/d of SO2 from the lower East Rift Zone, that is a very impressive amount, and is a testament to the eruption rate (more lava means more SO2 — the gas emission rate is proportional to the eruption rate). The acid gases have caused harm to all of the vegetation in the immediate vicinity of the eruptive vent and contributed to vog that is being detected as far away as Guam. People with respiratory issues have long had problems with vog on the Big Island, so the problem has been a persistent one.

Q: Noticed a recent 3.1 earthquake, shallow and uprift, just south of vents 9 and 10. Does this mean anything?
USGS: A single earthquake or two is not too much cause for concern given all of the magma pumping through the system. It becomes more concerning when there is a swarm of small earthquakes that might indicate persistent pressurization (there should also be some rift zone deformation if pressure is increasing).

Q: Any correlation between subsidence at summit and variations in lava flow in LERZ?
USGS: Good question. We can see evidence for a surge, or a pressure pulse (we’re not sure which), in tilt data from the area of Pu`u `O`o. But we don’t see surges from the eruption site that are related to the collapse events. It might be that any such surges are too smeared out to be detectable at the eruption site.

July 18, 2018. USGS: “Close view of the “end” of the open lava channel where lava moves beneath the crusted ‘a‘ā flow” [after making the turn around Kapoho Crater] (Full-sized)
Q: Past the end of the open lava channel, is it one or many tubes carrying lava the rest of the way to the ocean?
USGS: Impossible to know if it is one giant tube or many. Probably it branches, much like the channel above.

Q: Any sign of a lava bench like the one that happened in 2016 [lava from Pu’u O’o eruption]?
USGSVolcanoes: We haven’t seen any collapse events to speak of — the delta seems remarkably stable — but delta collapses are very random. We don’t have a good means of forecasting those (which is part of the reason why ocean entries are so hazardous).

July 8, 2018. USGS: ” Lava still oozes from the northern edge of the ‘a‘ā flow near the lighthouse at Cape Kumukahi (upper right). Smoke from burning vegetation marks location of lava oozeouts. View is toward the northeast.” (Full-sized)

[Update on HVO livestream problems.]
USGS:The problem is unfortunately more complex than just a network issue at HVO. It appears to be more widespread and beyond our direct ability to fix. We’re trying to work with others to resolve the problem, but still don’t have a timeline. We use that camera too, so we’re anxious to repair the issue also.

Tim Grooms on Facebook [crediting because i’m not just giving general gist of questions; these are pretty detailed comments]: Fernandina [Galapagos volcano, 1968 collapse mentioned in this week’s Volcano Watch]. has a much shallower water table, right? That is why there were some nice pyroclastic surges during the collapse? As for Kilauea at this point and looking over all the information I can find via legitimate studies and wonderful information y’all provide, this could be a long term subsidence event like the one that caused the massive lava flows and formation of the large caldera. To get a caldera collapse like this it takes some serious work to get that rock to start moving down those faults (from what I have read). Also, do you know much more about the size and depth of the actual intrusion? I can only imaging a fraction is being erupted at the surface. In my mind, at this point this can be considered a huge eruption/ intrusion event for any volcano of this type?
USGS: Yes, in fact, there was a lake within Fernandina’s caldera at the time of the 1968 collapse. As for the intrusion, that originates 2-3 km beneath the summit and is at least 2 km below the ground out to the eruption site, where it shallows to reach the surface. Parts of the East Rift Zone have spread apart by 4 meters to accommodate the intrusion.
You’re right — this is a huge eruption/intrusion for any basaltic volcano.

Tim Grooms: On the inflation/deflation trend [at the summit] that has it leveling out on the rim could this also mean the faults are locking up and subsidence on the larger faults is having a tough time? Could this lead to a much larger collapse because magma is still withdrawingfrom the summit area but the outer faults are not adjusting to the change in pressure underneath? Is another large earthquake possible along the décollement zone to adjust to all of this?
USGS:We actually haven’t seen any motion along the larger caldera rim faults. If there were lots of stress building on those faults, we might expect to see a change in the pattern of earthquake activity. As for the decollement, there is always a possibility of an earthquake there (that doesn’t require any “push” from the magmatic system). Hopefully the M6.9 dissipated a lot of the stress on that fault, but future large earthquakes there can’t be discounted.

From Photographers & Social Media

I usually can’t bear to dig very far into the #kilauea tag on Twitter because of all the conspiracy theorists and spam, but today I got farther than usual and found some interesting things.

ʻAILĀʻAU, THE FOREST EATER When Pele came to the island Hawaiʻi, seeking a permanent home, she found another god of fire already in possession of the territory. ʻAilāʻau (ʻAi-lāʻau) was known and feared by all the people. ʻAi means the “one who eats or devours.” Lāʻau means “tree” or a “forest.” ʻAilāʻau was, therefore, the fire-god devouring forests. Time and again he laid the districts of South Hawaiʻi desolate by the lava he poured out from his fire-pits. He was the god of the insatiable appetite, the continual eater of trees, whose path through forests was covered with black smoke fragrant with burning wood, and sometimes burdened with the smell of human flesh charred into cinders in the lava flow. ʻAilāʻau seemed to be destructive and was so named by the people, but his fires were a part of the forces of creation. He built up the islands for future life. The process of creation demanded volcanic activity. The flowing lava made land. The lava disintegrating made earth deposits and soil. Upon this land storms fell and through it multitudes of streams found their way to the sea. Flowing rivers came from the cloud-capped mountains. Fruitful fields and savage homes made this miniature worldbuilding complete. ʻAilāʻau still poured out his fire. It spread over the fertile fields, and the natives feared him as the destroyer giving no thought to the final good. He lived, the legends say, for a long time in a very ancient part of Kīlauea, on the large island of Hawaiʻi, now separated by a narrow ledge from the great crater and called Kīlaueaiki (Kīlauea-iki, Little Kilauea). This seems to be the first and greatest of a number of craters extending in a line from the great lake of fire in Kīlauea to the seacoast many miles away. They are called “The Pit Craters” because they are not hills of lava, but a series of sunken pits going deep down into the earth, some of them still having blowholes of sputtering steam and smoke. After a time, ʻAilāʻau left these pit craters and went into the great crater and was said to be living there when Pele came to the seashore far below. • #leilani #puna #kilauea #volcano #hawaii #gbradlewis #ʻAilāʻau

A post shared by G. Brad Lewis (@gbradlewis) on

Nice little blog post: