“Since May 16, 2018, the crater depth has more than tripled and the diameter has more than doubled.” ~ HVO
Current Eruption Summary
Volcanic activity has decreased over the past few days, at both the summit and down in the Lower East Rift Zone. However, as HVO warns us (and has stated many times), eruptions wax and wane, and can even stop and start up again. So we don’t yet know whether Pele’s winding down or simply taking a breather.
But for the moment, at least, Fissure 8 is putting out much less lava than before— in fact, this morning (August 5) its level is so far down that it’s barely feeding the channel. Lava levels were already lower and sluggish, and today the river is mostly crusted over and/or moving as thicker, crumbly a’a flows. However, blockages downstream are still causing overflows and breakouts.
Despite the slowdown at the source, lava continues to ooze into the ocean along a long section of the southern flow front. It’s edged a little bit closer to the boat ramp and local park that’s become a symbol for residents mourning the loss of so many other beloved places:
Lava tour boat operator Ikaika Marzo did not see any signs of slowdown at the flow front this morning, and he reported that lava has claimed claimed another popular local surf spot called “Dead Trees.”
At the summit, intervals between collapse events are lengthening. As of 5 pm August 5, it’s been over three days since the last summit collapse event. Today’s mini-update on HVO’s website states:
Rates of seismicity and deformation at summit and lava output from fissure 8 have decreased since most recent collapse event at 11:55 am HST August 2. Too soon to tell if the decrease will persist. Hazardous conditions remain.
Latest Satellite Imagery
Volcano Watch, August 3
And on August 3— before today’s significant lava decrease at Fissure 8— HVO posted out its weekly Volcano Watch column:
— USGS Volcanoes🌋 (@USGSVolcanoes) August 3, 2018
Outline of the rest of this post:
- Summary of USGS presentation at Thursday Volcano Village meeting
- Review of USGS eruption images from past few days (plus video)
- News and Kilauea-related information from other official agencies
- Kilauea-related headlines from local news media
- Overflight photos/videos of LERZ from @Hotseathawaii, etc
- USGS Q&A about eruption (and recent signs of change) on social media
Thursday evening Volcano Community Meeting
Thursday evening’s Volcano Village meeting (full video here) included a status update on Kīlauea’s summit from HVO geophysicist Ingrid Johanson (starting at timestamp 4:10). Johanson reports that the summit’s collapse cycle continues much as it has for the past two months: M5.3 earthquakes caused by the summit settling into the drained upper magma chamber, low SO2 emissions, not much ash since late May.
Johanson showed graphs of tilt/deflation and earthquake frequency illustrating this “collapse cycle,” and noted that the time between collapse events is increasing. Thursday’s collapse (video) was the 62nd.
Around timestamp 11:10, Johanson posted before-and-after slides of 2009 and 2018 Digital Elevation Maps, including fairly current figures:
- Volume loss (expansion of Halemaʻumaʻu Crater + caldera subsidence): about 800 million cubic meters, ~300,000 Olympic swimming pools
- Slumping area is about 1000 acres [over 4 km²]. Halemaʻumaʻu was about 1 km across when this started. [But I think “slumping” includes the wider area of the caldera floor that’s subsiding, not just H. Crater]
- Halemaʻumaʻu Crater depth on July 22: 1575 feet (“deeper than Empire State Building is tall”), 480+ m. It was ~280 ft deep (~85 meters) back in April.
- [On Facebook, USGSVolcanoes stated on Aug 4, “The depth of the crater floor has increased by more than 350 meters (1100 feet) since early May, 2018.”]
- The main floor of Kīlauea Caldera has subsided about 400 feet (~125 m)
Around timestamp 15:40 in the meeting’s video, Johanson shows a timelapse of caldera subsidence I haven’t seen posted elsewhere in its entirely.
USGS Photos posted Aug 3-5
Fissure 8 looking subdued…
Views of lava channel over past few days…
August 2 Pahoehoe:
— USGS Volcanoes🌋 (@USGSVolcanoes) August 4, 2018
Full-sized video posted on HVO website here. On FB, they specified the location of this video: “This is on the northern margin of the lava channel, which you can see moving slowly from right to left. The location is along the widest part near Pohoiki Rd & 132 just west of Lava Tree State Park.”
Ocean entry and Pohoiki…
Meanwhile, up at the summit…
From Local Gov’t Agencies
The Hawai’i Board on Geographic Names is meeting August 8 to discuss naming process for Fissure 8, as well as some other places.
Another important non-eruption news item is Hurricane Hector (National Hurricane Center Advisories, NWSHonolulu on Twitter). It looks like it’s going to miss the Big Island, but there’s enough uncertainty that people need to be prepared for a hit, just in case:
— NWSHonolulu (@NWSHonolulu) August 5, 2018
HDOT continues to keep Highway 11 open by repairing damage as it appears, as well as damaged portions of Crater Rim Drive needed as an emergency route. At a Volcano Village meeting Thursday evening, Civil Defense reported on plans to build two alternate emergency routes in case earthquakes make Highway 11 impassible.
On Friday, the Departments of Health and Education announced a joint volcano response plan to address vog and ash hazards for schools and students. The new school action plans are available partway down the DOE’s Kilauea eruption webpage, which has a lot of useful disaster preparedness and assistance resources for Big Island residents.
A member of our Incident Management Team scoops up volcanic ash behind Jaggar Museum. Most ash in the area was generated in May when explosive events at the summit were more frequent, and the plume clouds manifested were more prominent. #safety #lifeonavolcano NPS Video pic.twitter.com/OFMbXcs9GK
— Hawaii Volcanoes NPS (@Volcanoes_NPS) August 4, 2018
From Local News Outlets
- HTH: “Lava output significantly down, flow front oozes closer to Pohoiki boat ramp”
- HNN: “Could Kilauea finally be settling down? Activity has been rather quiet recently“
- HTH: “Hector regains category 4 status, continues track towards islands”
- BIVN: “Hawaii Readies For Hector, As Category Four Hurricane Approaches”
- HNN: “State creates ‘action plan’ to keep Big Island students safe from harmful vog“
- HTH: “Highway 11 alternate route could be completed in a week“
- HTH: “Kilauea eruption: Ige signs third proclamation“
- HSA: “Pay delays for Kauai flood and Kilauea lava duties irk Hawaii Guard members”
- HPR (Audio report, 3 minutes): “How Are Lava Tour Boats Regulated?”
- HSA: “Hawaii island eruption-related tourism losses could exceed $200 million“
- HSA: “Farmer hangs onto his home and business in Opihikao in spite of Kilauea eruptions“
- Meanwhile, Dispatches From Volcano’s Aug 3 entry identified details/features on USGS summit photos, and today’s entry warns people to be cautious of lingering hazards near lava flows, even if Fissure 8 pauses.
More Views From Above
Sunday, Aug 5, 2018, 6:00 am – Kilauea's lower east rift zone overflight: With the slowdown in lava supply from fissure 8, a recession within the perched channel is noticeable from this angle.
That’s the perched channel where it widened out into a sort of lava pond. As usual, look for houses for scale.
Sunday, Aug 5, 2018, 6:00 am – Kilauea's lower east rift zone overflight: The buildup of ‘a‘a in the lower channel has…
Sunday, Aug 5, 2018, 6:00 am – Kilauea's lower east rift zone overflight: A view of the eruption zone from above shipwreck corner, with overflows occurring from the lower braid through the bend.
Sunday, Aug 5, 2018, 6:00 am – Kilauea's lower east rift zone overflight: An active flow front, approximately 1 1/2…
It’s worth checking out the rest of that album for close-ups of specific features along the changing flow field, and sharp-eyed observation notes.
G. Brad Lewis overflight photos from August 4, late afternoon:
Big changes with the eruption. I shot this image with my iPhone at 5:30 pm on Aug. 4, 2018. The lava river has all but stalled. So-called fissure 8 is putting out a very small amount of lava from two areas within the fissure. (Very small is relative). A few leaks here and there within the tube system. Pohoiki remains in our world. And the summit has been as quiet as I’ve felt it in two months. So…. stay tuned boys and girls. #puna #kilauea #volcano #hawaii #gbradlewis
The evolution of an un-named Pu’u. The lava and earthquakes turned down like a switch. What does it mean? Is ‘Aila’au satiated? Did Pele just show up? Is the Dance about to begin? Or is chapter 62 in the book of this Kīlauea Volcano eruption closing? One thing that this current eruption has taught us is that NOBODY KNOWS what’s going to happen. This living planet is so much bigger than us tiny silly humans. Creation will have its way. If we can live another day, then the more power to us. Respect and humility begins at home. Aloha. • #leilani #puna #kilauea #volcano #hawaii #gbradlewis
Compare with Andrew Richard Hara’s August 2 overflight photos.
And back to August 5:
USGS Q&A on Social Media
[Oho! Apparently something’s stirring at Pu’u O’o, or at least there’s enough of a signal that USGS is checking it out. ]
USGS on Facebook: “The increase in gas emissions from Pu`u `O`o is certainly interesting and suggests shallow magma, but we’re not seeing deformation nor seismicity indicative of a backup.”
“We’re planning on another flight tomorrow, if weather cooperates, with a thermal camera on board.”
Q: If a new eruption at Pu’u O’o were to start, would it be considered new or part of previous one?
USGS: We’re not really sure what we would call it at this point if Pu`u `O`o were to restart. We haven’t even had a big discussion yet about whether or not we want to call the new fissure system a “new” eruption (we’ve got passionate viewpoints on both sides).
Question posted on FB this evening: Hawaii Civil Defense just posted no movement in the lava channel. Is this true?
USGS, about 8pm HST: “There is no movement of lava in the channel. Confirmed.”
Another asked about summit inflation.
USGS: “No, there aren’t any indications of summit inflation at this point. All of the indicators are pretty flat right now — no inflation, no deflation.”
Q: [How do you determine when this event has concluded?]
USGS: We expect things would quiet down on the volcano for a while — weeks, months, perhaps years. That would be the conclusion of the event. But these events often sputter to a close, and it might be that Fissures in the system reactivate briefly before things go completely quiet. The ends of eruptions are very chaotic and subject to numerous conditions that are difficult to forecast.
Q: [More specific question about outcome of eruption on summit]
USGS: We expect the caldera will continue subsiding to some degree even after the lower East Rift Zone eruption is over…probably for a couple of months after. When it all stops, magma will return to the summit – like it has done repeatedly after collapses that followed 1925, 1955, 1960, and even after the collapse of the last caldera in the 1400-1500s. Kilauea is young and is still building itself…it will continue to do so.
[Response to several questions]
USGS: 1) The Koa`e earthquakes are a response to the downdropping of the summit. Most of those faults dip to the north, towards the caldera. We can see from satellite deformation maps that faults there are rupturing, and have been since late May. 2) We doubt that the M3 south of the summit was anything significant, given all of the other seismicity. The earthquakes are a consequence, and not a cause, of the activity we’re observing. 3) Iki is in line with other summit tiltmeters that show a leveling off of the deformation.
Since PGCam got toasted in a brushfire, USGSVolcanoes pointed to lavacam.com, a new webcam pointed towards Fissure 8. Also, as the KE cam keeps disappearing from the webcams page, here’s a direct link: https://volcanoes.usgs.gov/observatories/hvo/cams/KEcam/images/M.jpg
[Next comment was posted first thing this morning (Aug. 5) on FB, in response to “what’s going on?” type questions.]
USGS: As Tim mentions, this is kind of a waiting game. These eruptions wax and wane. But, the decrease in activity from the fissure system in addition to the flat deformation and decreased earthquakes at the summit indicates to us that magma has ceased leaving the summit storage region. We will have more analysis published in the update later this morning.
[Q: Why is this eruption different from previous, shorter LERZ eruptions? (Asked on Aug 3, when Fissure 8 was still flowing)]
USGS: Eruptions stop when the supply of eruptable magma is extinguished. This eruption is different from historic lower East Rift Zone eruptions for a few reasons. 1) there was a lava lake AND a long-lived eruption in the middle east rift prior to change in activity (two different storage regions of magma drained and have erupted from the LERZ). 2) The M 6.9 earthquake plus foreshock/aftershock sequence occurred at the start of eruption, and we believe it opened up a portion of the ERZ that was blocked, allowing magma to flow from summit.
[Q: If Hurricane Hector hit, what could storm surge do to lava? Will your summit cams be ok?]
USGS: The webcams are located in the HVO Observation Tower, so they will [hopefully] be okay. The lava delta is another story. It is somewhat unstable because it is built on unconsolidated lava fragments and sand. This loose material can easily be eroded away by surf, causing the new land to become unsupported and slump into the sea. Here is the link to summit webcams, in case anyone wants to take a quick peak, https://volcanoes.usgs.gov/…/multimedia_webcams.html
On Aug 4, before current slowdown, USGS answered another question about how “massive amount of water” from hurricane could affect lava flows:
USGS: You’ve seen the video, how the surface of the lava flow chills to form thin crusts. A lot of rain could help that process along a bit, but consider that lava has been coming out of fissure 8 at (roughly) 50 to 150 cubic meters per second (65–196 cubic yards per second). At that rate, lava will keep chugging toward the sea, even if a hurricane were to occur.
@USGSVocanoes retweeted this from (I think) a member of a UK research group that’s working on new ways to measure high SO2 emissions:
MultiGAS inter-comparison exercise at #Kilauea today – ensuring standardised data between research groups is an important part of collaborative monitoring of volcanic gas hazard @deepcarb @USGSVolcanoes @EarthSciCam pic.twitter.com/glbwW6eO0G
— Emma Liu (@EmmaLiu31) August 4, 2018
Following that Tweet back to its source led me to more Tweets by this scientist and by others doing fieldwork for various international scientific teams. It’s not just HVO that’s studying Kīlauea! So if you’re curious about some of the research being done on this eruption, go look at these Twitter channels and see what else they’re posting/retweeting:
High SO2 emission rates at #Kilauea Fissure 8 are challenging for spectroscopic measurements – but with a little help from our friends @sheffieldgeog preliminary processing of longer wavelength #raspberrypi UV camera imagery looks promising! #PlumeTeam @EarthSciCam pic.twitter.com/SAfVq6aq21
— Emma Liu (@EmmaLiu31) August 1, 2018
Aerosol sampling equipment at work 1000 feet above the ground. UAS has been a game changer for those of us interested in how volcanoes impact #AirQuality. A big #eruption like #Kilauea is practically impossible to sample at ground level close to the source #PlumeTeam @USGS pic.twitter.com/AzjVTkCULZ
— Evgenia Ilyinskaya (@EIlyinskaya) July 29, 2018
#PlumeTeam working out by Fissure 8 again today 🌋 working on this tephra field allows us to sample the concentrated plume and understand the trace element emissions as #KilaueaErupts @USGSVolcanoes pic.twitter.com/fOvyKplQ5g
— Em Mason (@emilymmason) July 29, 2018