July 23: Pohoiki Going Tonight (I Think)

July 23, 2018. View of lava channel from F8 where it bends to south and heads for ocean (laze plume in background). USGS: “The fissure 8 channel continues to carry lava toward the coast on the west side of Kapoho Crater (vegetated cone, far left). Northwest of this cone, overflows (lower left) of the channel occurred overnight, but lava was confined to the existing flow field and did not threaten any homes or structures.” (Full-sized)
Today’s Eruption Summary

The USGS has updated the energy release for yesterday evening’s summit collapse to  M5.5. (For more info: “Why Do Earthquake Magnitudes Sometimes Change?” from a 2016 issue of Volcano Watch by HVO.)

Fissure 8 exhibited surge behavior afterwards. Overnight, drone crews observed minor overflows just northwest of Kapoho Cone, most of which were confined to the existing flow field and/or stopped before traveling far enough to threaten structures.

July 23, 2018. USGS: “Lava continued to enter the sea near Ahalanui during HVO’s early morning helicopter overflight of Kīlauea’s lower East Rift Zone (view to northeast). The southern margin of the flow was still about [a quarter mile] from the boat ramp at Isaac Hale Park this morning. The jetty along the launch ramp is visible near the center of the photo.” (Full-sized)
The main ocean entry and southern margin of the flow haven’t moved much in the past few days. However, USGS reports “a new lobe has started from the southern lobe and is active along its southwestern margin, slowly heading towards the ocean.” Today’s 1 pm map clarifies the new lobe’s location:

July 23, 2018, 1 pm USGS map of LERZ lava flow field. Note small overflow by Fissure 8 as well as upstream of Kapoho bend on the north side of the braided channels. (Full-sized)

Ikaika Marzo, a lava tour boat operator who stays a sensible distance from shore, reportedly saw lava is in Isaac Hale Park, within 50 m of Pohoiki boat ramp at 7:15 this evening.

No summit collapse today, unless the pattern changes; the next one ought to occur tomorrow morning.

Here’s highlights of the USGS Media Conference Call from this afternoon:

Full audio file archived here.

From Other Scientists

From Local News Media
@HotSeatHawaii morning overflight

Mick Kalber posted two overflight videos today. Here’s July 23— he said wind conditions made it difficult to document the Leilani portion of the eruption today:

Also posted today: July 22 overflight video.  Notes/observations for both of these days: July 22 | July 23

And Bruce Omori posted HD camera still photos from this same flight.

Monday, July 23, 2018, 6:00 am – Kilauea's lower east rift zone overflight: A view of the new sand bar that formed when flows began encroaching upon Pohoiki.

Posted by Extreme Exposure Fine Art Gallery on Monday, July 23, 2018

Monday, July 23, 2018, 6:00 am – Kilauea's lower east rift zone overflight: Inland margins of the flow field have…

Posted by Extreme Exposure Fine Art Gallery on Monday, July 23, 2018

Monday, July 23, 2018, 6:00 am – Kilauea's lower east rift zone overflight: Low cloud cover prevented us from accessing…

Posted by Extreme Exposure Fine Art Gallery on Monday, July 23, 2018

See 14 more Bruce Omori photos plus notes. (They also livestreamed this flight on Twitter, but that cam is lower quality.)

USGS Q&A on Social Media

[The following FAQ looks to have been composed in June, even though HVO just announced it on Twitter. However, the explanation of summit collapses and subsidence remains the same, since July was “more of same.”]

Q: Re: caption on South Sulphur Bank photo — has Kīlauea caldera been filled with 65 m of lava in 150 years? 

USGS: Yes, that’s what it implies. A 300-year period of explosive activity ended in 1823, after which effusive activity (lava flows) slowly filled the summit caldera. You can read about the history here: https://volcanoes.usgs.gov/volcanoes/kilauea/geo_hist_summary.html

Q: [Is there a source that covers the lava flows/eruptions mentioned on that page in more depth?]

USGS: For that you’ll want to check out the “Eruptions of Hawaiian Volcanoes – Past, Present and Future” book found here: https://pubs.usgs.gov/gip/117/

Q: Is there a perched pond forming by Kapoho Crater?

USGS: There is an area at the bend in the channel where there has typically been ponding, yes. It has fed some overflows.

Q: [Belated question: how did that island form offshore from lava delta?]

USGS: One idea is that it was an inflationary feature – underwater lava flows crusted over, then inflated themselves with more lava and pushed the ‘island’ above water. It later became connected to the delta with an isthmus, which may have formed over the lava supply location.

July 23, 2018. USGS: ” Hawaiian Volcano Observatory field geologists track volcanic activity at fissure 8 (spatter cone in background). They collect tephra (airborne lava fragments, such as Pele’s hair, pumice, and other lightweight volcanic glass) for geochemical analyses and observe the fissure 8 vent to characterize changes in lava fountain behavior.” (Full-sized)
July 23, 2018. USGS: “As part of their ongoing monitoring work, HVO scientists measure temperatures at ground cracks along the fissure system in the Leilani Estates subdivision. On this day, temperatures ranged from from 100 to 145 degrees Celsius (200–300 degrees Fahrenheit), which is consistent with past readings.” (Full-sized)

Q: [Where can we find records of sulfate measurements throughout this eruption?]

USGS: Gas measurements are made intermittently, unlike seismic/deformation monitoring. Some have been posted in HVO updates (https://volcanoes.usgs.gov/volcanoes/kilauea/status.html …) and chronology (https://volcanoes.usgs.gov/vsc/file_mngr/file-179/Chronology%20of%20events%202018.pdf …) but for regular monitoring, you’d have to look at air-quality stations: https://vog.ivhhn.org/

Rumor Whack-a-Mole

[Again debunking that “puff emissions = magma returning to summit” claim by a self-proclaimed expert who’s taken in a lot of people on YouTube.]

Q [John Calvert]:  Aloha ~ what do you make of the “puff emissions” that have been happening? Does this signal a possible return of magma to the caldera? (sorry if this has already be asked). Mahalo!

USGS: No “puffing” emissions. Steam rises from crater b/c rain water enters the ground and is heated by surrounding rocks. A long-time process @ Kilauea summit. Also, steam often prevalent in morning b/c of dew point. Subsidence = magma draining. Inflation will signal magma return.

[Kīlauea has always wafted up puffs of steam like this, long before the current eruption. In fact, any volcano with hot rocks near the surface may do this, as I witnessed a year ago.]

August 22, 2017. Mount St. Helens. Own photo. The sky was clear and cloudless, but as the air cooled in late afternoon, little puffs of steam started rising from within the crater, which is partly occupied by a still-cooling lava dome that erupted 2004-2008. (Full-sized)
Other Photographers and Social Media

Sad day today. Good chance Pohoiki will be taken today. Lava have moved almost 200yards in one day. The new ocean entry…

Posted by Ikaika Marzo on Monday, July 23, 2018

Lavabergs the size of a VW Westfalia van silently travel as glowing cracks reveal incredible internal temperatures within the core. . Lava channel speeds remain at 5-10mph and 5-10ft from the brim as various lavabergs silently meander toward Kapoho. Several surface cooled lavabergs were spotted shipwrecked further down the channel west of Sanford Quarry near Noni Farms Road. Lava levels and activity remain consistent throughout the weekend. . My respect and best wishes go out to all who have been impacted by the eruption experience. There are no words to describe the amount of loss, personal tragedy, and stress our community has been experienced. . *** Please visit my eruption relief fund if you would like to purchase a print from my profile link to help our displaced eruption evacuees. This gallery will continuously be updated, please check back for new photographs*** . #fissure #kilauea #volcano #bigisland #hawaii #lava #lavaflow #lavachannel #timelapse #geology @hawaiicommunityfoundation #puuhonuaopuna

A post shared by Andrew Richard Hara (@andrewrichardhara) on

A massive surge occurred today from Fissure 8 causing a large volume of lava to flow downstream, widening the flow closer towards Pohoiki. Surf spots Shacks and Bowls have been consumed by the ocean entry and continue out to sea. . My respect and best wishes go out to all who have been impacted by the eruption experience. There are no words to describe the amount of loss, personal tragedy, and stress our community has been experienced.
. *** Please visit my eruption relief fund in my profile link if you would like to purchase a print from my collection to help our displaced eruption evacuees. This gallery will continuously be updated, please check back for new photographs*** . #fissure #kilauea #volcano #bigisland #hawaii #lava #lavaflow #lavachannel #geology @hawaiicommunityfoundation #puuhonuaopuna #pohoiki

A post shared by Andrew Richard Hara (@andrewrichardhara) on