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96408
From: ao, [DNS_Address]
Subject: Mauna Loa eruption 12/07/2022 Update - Is the End Nigh?
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Or are things just slowing down a bit? It’s been a few days since there were any notable changes at Mauna Loa. The eruption continues and the flow continues to slow in its advance across the flatter terrain it reached a few days back. This suite of thermal images..  Taken between November 30, December 5, document the flow from when it first hit the change in grade. Note that in the first three images from the left, which are each a day apart, the rate of advance between one day and the next remains close to the same, with only a minor amount of slowing over the three days shown. Then, by contrast the next, the forth panel, shows close to the same distance traveled but is the accumulation of three days of elapsed time since the last. Also note the width of the flow front is far more than a kilometer wide now. By comparison, this is the latest HVO map, this one from yesterday, 12/06, that shows continued, yet still slowing and broadening, advance..  Aside from the mapping of the surface activity, I would say (without actual measurements to back it up) that over time the fountaining as seen at the HVO streaming webcam that is (was?) here.. From.. https://www.youtube.com/watch?v=SnjGqn1K9ZQ But is not broadcasting at the time of this writing so I’m falling back on their once every 10 minutes or so still webcam view here.. From.. https://www.usgs.gov/media/webcams/m8cam-mauna-loa-northeast-rift-zone-fissure-3-eruption-live-view  The fountaining appears to not be as high or vigorous as in days past. This morning, here in Hawaii, that fountain looks sluggish. But those two points are not enough to speak of trends and such on the surface, yet instrumentally maybe there’s something to back them up.. In earlier posts I focus on three plots of different geodetic data.. the summit tilt which measures the angle of the flank of the volcano adjacent to its summit and shows changes relative to the rising and falling and expansion and contraction of the summit, as well as the same being recorded with two GPS plots, one showing the distance across the caldera and the other the vertical rise and fall of a point on the northwest side of the summit caldera. Here these three plots are again.. First a look at the summit tilt..  With its spike (recording a 3.48 magnitude earthquake at the summit) late on the night of12/05 that has tapered off to almost flat since. And a similar change in the GPS vertical component, ie showing a slowing down in the rate of change, can be seen between the last few data points than seen in days past here..  As does the the change in distance across the summit caldera show signs of slowing.. but not as graphically in the last day as the data above.  All combined, the data seems to suggest if not a slowing down of the eruption at least a slower phase when compared to earlier periods. Of course all this is preliminary, and only the first in what would need to be a series of changes that would be enough to draw any kind of conclusion. But, it’s fun to observe, and speculate.. *I added the instrument plots not as dynamic, as I have in past posts, but statically, snap shots of the point being discussed, in that the scale of those plots change with large events, earthquakes causing offsets and such, and where the tilt now can show precise changes, if we have another larger earthquake these changes could be drowned into the background of bigger changes. |
96412
From: ryan, [DNS_Address]
Subject: Re: Mauna Loa eruption 12/07/2022 Update - Is the End Nigh?
URL: https://www.sfgate.com/news/article/Mauna-Loa-lava-no-longer-imminent-threat-to-17641071.php
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Mauna Loa lava no longer imminent threat to Hawaii highway JENNIFER SINCO KELLEHER, Associated Press Dec. 8, 2022 HONOLULU (AP) — Lava from the world's largest volcano is no longer an imminent threat to the main highway across the Big Island of Hawaii, scientists said Thursday, a development that was a welcome reprieve for motorists who depend on the road. Mauna Loa was still erupting Thursday morning, but the lava that was feeding the flow heading toward the crucial road has been cut off, likely because of a reduced production rate, said David Phillips, deputy scientist-in-charge at U.S. Geological Survey’s Hawaiian Volcano Observatory. “That’s good news for us,” Hawaii County Mayor Mitch Roth said. Still, county officials said they will stay on the alert — because scientists say things could always change. Lava from Mauna Loa, which began erupting Nov. 27 after being quiet for 38 years, was 1.76 miles (2.83 kilometers) from Saddle Road, also known as Route 200 or Daniel K. Inouye Highway, the U.S. Geological Survey said. “So just to emphasize, there is no current threat to any island communities or infrastructure at this time,” Phillips said. Last week, officials said the earliest the lava could hit the road was one week, prompting motorists to brace for upheaval from a possible closure that could add hours to commute times on alternate coastal routes. But, as expected, the lava slowed considerably in recent days as it moved across flatter ground, leaving scientists unable to estimate a clearer timeline. Phillips said the active fissure is still generating lava flows, but they'll be localized around the fissure. If there are additional flows in the channel, it's very unlikely that supply from the top will push the flow front ahead to become a threat, said Frank Trusdell, a geologist with the volcano observatory. “So right now, we don’t expect that the new lava coming out on the surface to be able to replenish the supply to the flows that are closest to Daniel K. Inouye Highway,” he said. Meanwhile, scientists were trying to understand why lava fountains were higher than usual overnight — a marvel noticed by people across the island, Phillips said. There wasn't a good estimate of size, he said, but the fountains were at least several hundred feet. Some 20,000 vehicles have used a viewing route, which opened last week in an attempt to manage throngs of nighttime lava-gawkers, officials said. Authorities were giving citations to people who, in an attempt to get a closer look, ventured onto prohibited areas. The state was “investigating people and companies who have entered the closed area and posted shots of themselves and lava flows on social media,” said a statement Thursday from the Department of Land and Natural Resources. Native Hawaiian community members planned to be out along the highway Friday to ensure the area is free from garbage. “And so as we do when we are preparing for the arrival of Pele, it is a practice for many of us to prepare our homes, prepare the areas where we live, and to make sure that that these areas are clean,” said Hawaiian cultural advisor Noe Noe Wong-Wilson, referring to the deity of volcanoes and fire. For many Native Hawaiians, an eruption of a volcano like Mauna Loa has a deep yet very personal cultural significance. |
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[96413]
96413
From: ao, [DNS_Address]
Subject: Re: Mauna Loa eruption 12/07/2022 Update - Is the End Nigh?
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Meanwhile, scientists were trying to understand why lava fountains were higher than usual overnight Actually, I wonder if it's not as much of a mystery as all that. Of course in any observational science it's best to let the evidence speak for itself.. but playing armchair volcanologist and there being extra points for speculation... Imagine a pipe.. the dike.. the tube through which magma ascends to the surface is filled with so much.. it's full, if you will, in equilibrium with the pressures behind it and the surrounding rock's tensile strength. And now, for days, magma has been coursing through it to feed the steady state eruption we saw for the last week plus. The same steady decline in the mountain as a steady flow of lava erupted... steady. And that was after the surge, the pressure surge of opening up the mountain in the first place had relaxed. Then, when that earthquake happened a few days back, there was a sudden change, a drop in the rate of change in the deformation.. a drop in the rate of lava erupted. So we can imagine that the space that was before occupied by the greater amount of magma is now filling up with gases that are dissolving out of the melt at a higher rate because of the drop in pressure. And.. the more gas venting the higher the lava is carried into the air. It's like the difference between opening a soda and there's that much bubbly and it's a pleasant drink, and shaking it up before you pop the lid. There's always the potential.. but there needs to be a specific set of circumstances to unleash it.. |
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96409
From: shatterbrain, [DNS_Address]
Subject: Re: Mauna Loa eruption 12/07/2022 Update - Is the End Nigh?
| Thar she BLOWS......again. |
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