Kilauea Eruption 9/29/21

[HereOnThePrimalEdge]

New eruption in Halema'uma'u crater:

The volcano is erupting as of Wednesday, Sept. 29, 2021, at approximately 3:20 pm. According to an official release, the USGS Hawaiian Volcano Observatory (HVO) detected glow in Kīlauea summit webcam images indicating that an eruption has commenced within Halemaʻumaʻu crater in Kīlauea’s summit caldera, within Hawai‘i Volcanoes National Park.
https://bigislandnow.com/2021/09/29/kila...wednesday/

Article with photos:
https://www.reuters.com/world/us/hawaiis...021-09-30/

USGS Summit Cams:
https://hvo.wr.usgs.gov/cams/

[ChunksterK]

Isn't this one a bit of a surprise? I don't recall hearing anything about an imminent eruption as in previous episodes.

[dobanion]

I was expecting it, only because I have a earthquake alert thing on my phone for the area around the summit. Been lots of 2.5-3.5 quakes clustered under the crater and getting shallower as they progressed.

[HereOnThePrimalEdge]

Message from USGS Volcanoes:

Don't worry! There's no danger to Pahoa from this eruption - it's confined to the summit crater of Kilauea, and we haven't seen any evidence of activity in either of the rift zones.

[HereOnThePrimalEdge]

Isn't this one a bit of a surprise? 

It was to me, but here’s what occurred yesterday:

DID SCIENTISTS KNOW IT WAS COMING?
Scientists at the Hawaiian Volcano Observatory noticed a surge of earthquakes about 5 miles (8 kilometers) east of the summit's caldera early Wednesday. By the afternoon another series of earthquakes accompanied by ground swelling prompted them to increase the alert level.
“We picked up a series of earthquakes down the east rift zone, so on the order of about 5 miles from the summit. And these kind of came in what we would call a small swarm. So one after another," said Ken Hon, the USGS scientist in charge of Hawaii Volcano Observatory. "They were enough of an alert that we became suspicious that pressure was building within the system.”
The agency raised its alert level “to orange or watch, anticipating that there might be an eruption,” Hon said. "And 20 minutes later, in fact, there was an eruption.”


https://www.yahoo.com/news/explainer-fou...12747.html

[Obie]

They knew it was coming but based on years of research they determined it would either quiet down or be a non life threatening event !

So far just in the Park. I hate to hear the helicopter noise again .

[eightfingers2.0]

Helicopters was what I was thinking..

[Carey]

Not really a surprise, the earth quake swarms over the last few weeks had already elevated the warning & on Wednesday, hours before the eruption, the warning was raised to Orange. On Tuesday they were still at the lower, yet raised levels from the intrusion swarms that subsided Aug 30 when magma intrusion subsided, yet was still ʻon the radarʻ (from what I have noticed...if they mention it, they are still evaluating it):
HAWAIIAN VOLCANO OBSERVATORY WEEKLY UPDATE
U.S. Geological Survey
Tuesday, September 28, 2021, 8:04 AM HST (Tuesday, September 28, 2021, 18:04 UTC)


KILAUEA VOLCANO (VNUM #332010)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Activity Summary: Kīlauea Volcano is not erupting. Following the recent intrusion of magma beneath the surface in the area south of Kīlauea caldera, which slowed substantially on August 30, earthquake rates and ground deformation in this area have remained near pre-intrusion levels. Other monitoring data streams, including sulfur dioxide emission rates and webcam views, show no significant changes.

Summit Observations: Over the past week, 109 small-magnitude earthquakes—all below M2.5—were detected beneath the summit region of Kīlauea. These earthquakes occurred approximately 1-3 kilometers (0.6-1.9 miles) below ground level near Halema‘uma‘u. There has been no notable seismic activity in the vicinity of the recent intrusion. Since August 30, tiltmeters have not detected any substantial ground deformation in the summit region. These observations suggest that the supply of new magma to the intrusion has stopped. "

& the last of the Wed pre-eruption notices (~ten minutes later the volcano erupted)
"HVO/USGS Volcanic Activity Notice

Volcano: Kilauea (VNUM #332010)

Current Volcano Alert Level: WATCH
Previous Volcano Alert Level: ADVISORY

Current Aviation Color Code: ORANGE
Previous Aviation Color Code: YELLOW

Issued: Wednesday, September 29, 2021, 3:09 PM HST
Source: Hawaiian Volcano Observatory
Notice Number: 2021/H261
Location: N 19 deg 25 min W 155 deg 17 min
Elevation: 4091 ft (1247 m)
Area: Hawaii

Volcanic Activity Summary: Kīlauea volcano is not erupting. Increased earthquake activity and changes in the patterns of ground deformation at Kīlauea’s summit began occurring as of approximately noon on September 29, 2021, indicating movement of magma in the subsurface. At this time, it is not possible to say with certainty if this activity will lead to an eruption -- the activity may remain below ground, as occurred in August 2021 and early December 2020 (two weeks prior to the December 2020 - May 2021 summit eruption), when magma intruded beneath the caldera but did not erupt. However, an eruption in Kilauea’s summit region, within Hawai‘i Volcanoes National Park and away from infrastructure, is one potential outcome.

The US Geological Survey Hawaiian Volcano Observatory is raising the volcano alert level/aviation color code for Kīlauea from Advisory/Yellow to Watch/Orange due to this activity.

HVO will continue to monitor this activity closely and adjust the alert level accordingly.

HVO is in constant communication with Hawai‘i Volcanoes National Park as this situation evolves. The activity is confined entirely within the park. "

[MyManao]

I don't recall hearing anything about an imminent eruption as in previous episodes...

Yeah, this eruption wasn't as noisy in its onset as a bunch of breaking ground on the way to the surface would usually entail. But then, when we think of the pounding the caldera and associated magmatic structures endured back in 2018, I think it's reasonable to envision the summit as a pile of ruble contained within a vertical rock tube, verses the often thought of solid layer upon layer built up miles thick roof over a magma body safely contained within that we're used to. As such there's nothing to break, to force open, rather than just push aside. And, not much seismic noise.

I'm toying with the idea of an open chimney from depth to the surface which doesn't require a lot of built up energy to break ground. Instead, a pulse of magma comes into the system and passes, without any appreciable resistance, through to the surface..

Yeah, I know, it's simplistic, and surely there's a myriad of other forces involved.. and still, without the initial fissure eruption driven by an abundance of pent up energy I began to imagine that deep earthquake back in August near Pahala leading to the shallow seismic swarm South of Kilauea's summit a few weeks later, leading to the just started eruption as one continuous series of events. Magma rising though a broken up edifice and spewing, without much fanfare, onto its surface. Maybe not the same magma, but a batch entered the system and without any resistance its energy was transferred hydraulically to the summit and 'pushed' the magma that was closest to the surface.

I like that idea.. as if we get a spell in which all the other stuff, storage under accumulating pressure and eruption/pause cycles at vents on the flank, etc., aren't a part of the things we consider. But rather, we get a feel for how the Earth itself supplies Kilauea directly. Its waxing and waning. Its heartbeat. How much magma is in a 'batch,' are they always the same amount, or do they vary? And if so why? Things that were, until now, hidden under so many other layers, other forces. Fun.

If my vision (and yeah TomK, we know, I'm a raving maniac) is anywhere near what is happening then the amount of lava erupted will be in some way equal to the amount of magma that entered the system behind it. And, my sense, considering the scale of the events that preceded this eruption, it will end in short order. And we'll have other similar events soon as well..

[HereOnThePrimalEdge]

the amount of lava erupted will be in some way equal to the amount of magna that entered the system behind it.

Pretty good, and you can dance to it, but not quite as snappy as the original:
And in the end, the love you take is equal to the love you make.  - The Beatles