Mount Agung volcano

[SN_Lover]

Breaking911: DEVELOPING: Bali's largest volcano could be about to explosively erupt; 75,000 people have been evacuated from their homes. The last time Mount Agung erupted in 1963 it killed more than 1,000 people

 

 

 

 

Volcano has a VEI of 5. Similar VEI 5 eruptions: Vesuvius (79), Fuji (1707), Mount Tarawera (1886), Mount Agung (1963), St. Helens (1980), Mount Hudson (1991), Puyehue (2011)

[raindancewx]

I don't know if it will erupt in a big way, but the aerosols were forecast to reach 45,000 feet asl (above sea level) earlier today, so that implies to me further eruptions may send ash higher. Bali is near the La Nina, so if it gets the ash up further than it is now, it has some implications for weather with or w/o a big VEI eruption.

 

[Windspeed]

Lahars (volcanic mudflows of ash and debris) have started due to heavy rains mixing with fresh ashfall.

 

https://www.reuters.com/article/us-indonesia-volcano-mud/indonesia-warns-cold-lava-flows-to-increase-from-balis-mt-agung-idUSKBN1DR078

[Windspeed]

Good translation thread of current situation by Dr. Krippner.

 

[CoastalWx]

You really need a massive eruption into the stratosphere for any real implications. These eruptions that have been mostly in the troposphere happen frequently across the globe.

[Maestrobjwa]

12 minutes ago, CoastalWx said:

You really need a massive eruption into the stratosphere for any real implications. These eruptions that have been mostly in the troposphere happen frequently across the globe.

How massive? I'd imagine (in my completely non-expert, volcano newbie opinion) if it were to be a VEI 5 like it did before...that would be enough, wouldn't it? Lol 

[Windspeed]

1 hour ago, Maestrobjwa said:

How massive? I'd imagine (in my completely non-expert, volcano newbie opinion) if it were to be a VEI 5 like it did before...that would be enough, wouldn't it? Lol

 

Hence, the big question. How intense does the current cycle of eruptions at Agung get? Current activity could be a precursor to a much larger event or activity at Agung could wane or even subside completely.

 

The velocity of the ash columns have not come close to main 1963 paroxysmal event yet. Particulates and gases reached over 26 km high into the stratosphere during peak intensity. But not every eruptive episode is going to escalate to such a degree regardless of the eruptive history of the volcano. Obviously, the threat remains however.

 

In my own speculation, I do not imagine we have seen the worst out of this new period of activity. That doesn't mean we are going to see a VEI level 5 eruption either. Nevertheless, based on the seismic record from September and October, including changes in ground deformation, PVMBG had estimated over 150 million cubic meters of magma had accumulated in the recent recharging episode. That report was released in October. Though seismic activity decreased in intensity into November, and perhaps the recharge slowed, the previous figure is more than enough new magma to cause a potentially large violent eruption. As rock of the old conduit continues to break down under pressure, the threat of a large release of this material remains high.

[Windspeed]

Mount Agung: Bali volcano eruption photos explained

https://www.bbc.com/news/amp/world-asia-42133502

[Windspeed]

The ash column is sustained without much abating right now. There is also a low-frequency harmonic (volcanic) tremor.

[Paragon]

On 9/26/2017 at 4:00 AM, Windspeed said:

I want to go back and clarify my comments. The question was could Agung erupt with the same magnitude as the VEI 6 Pinatubo eruption, and yes, it could. But when I said a VEI 3 or 4 event is more probable, in respect, I did not mean that an eruption of those magnitudes is likely to be the outcome of current precursor activity. Just way more likely than Agung's last major eruption such as the VEI 5 of '63. Current seismic activity could just as easily lead to smaller eruptive episodes or subside. The evidence of inflation, seismic activity and an increase in fumerole activity would suggest some type of eruptive acitivity could be imminent in the coming days or weeks. But that still isn't a certainty that a large eruption will occur.

 

The worry with the Bali volcanoes is their explosive eruptive history and close proximity to surrounding population. The islands have large ignimbrite deposits from caldera forming eruptions such as Bakur. But even much smaller eruptions are an extremely dangerous threat to the communities that exist there.

 

That region has a bad history with volcanoes/tsunamis/earthquakes.  I'd be highly concerned.

 

[Paragon]

On 9/26/2017 at 4:29 AM, raindancewx said:

I saw a quote from some of the older people near Agung, who survived the 1963 eruption, they said essentially they think it will erupt, but not for a few months. Will be interesting to see when/if it does. It's interesting looking at the AMO values in 1963, big crash almost immediately after Agung erupted in March, but it may be a coincidence.

It has been a while for a 5 or greater eruption in the tropics (23S to 23N), last one was Pinatubo in 1991. Wikipedia has five eruptions that were VEI 5 or higher in the tropics from 1900-1999. 

The VEI scale page on Wikipedia implies the sixes are once to twice a century, fives are once every 12 years, with the fours every 18 months. Only one five since 1991 though, and it wasn't in the tropics.

Pinatubo was already mentioned, but what was El Chichon? I found that to have had a greater effect on climate (at least around here.)  We also had one of the darkest lunar eclipses we've ever had in December 1982.  That's a hallmark of strong volcanic eruptions.  The moon actually looked darker than the background sky- like a giant black hole!

 

[Paragon]

59 minutes ago, Windspeed said:

The ash column is sustained without much abating right now. There is also a low-frequency harmonic (volcanic) tremor.

Do you think it's these low frequency events that lead animals to evacuate before the actual big event occurs?  It was reported that elephants were leaving the area and heading towards higher ground ahead of the Indonesian Tsunami back in 2004.  And it was documented that animals at the National Zoo in DC (particularly orangutans) got extremely restless half an hour before the earthquake occurred in 2011.

 

 

[Windspeed]

Do you think it's these low frequency events that lead animals to evacuate before the actual big event occurs?  It was reported that elephants were leaving the area and heading towards higher ground ahead of the Indonesian Tsunami back in 2004.  And it was documented that animals at the National Zoo in DC (particularly orangutans) got extremely restless half an hour before the earthquake occurred in 2011.

 

 

Low-frequency long period events and harmonic tremors aren't necessarily strong enough to be felt outside of 8 km or so from the source by humans unless magma is already exiting the system explosively. In other words, if you're feeling a low rumble, you're already in trouble. Typically, you need seismic equipment to detect a harmonic tremor.

As for animals, I'm not discrediting the phenomenon. I just don't know. Obviously, certain animals perceive sounds and vibrations humans do not always perceive or cannot perceive. I'm just not familiar enough with any science on the subject to state either way, especially when it comes to precursor activity leading up to an event.

I can say without hesitation that if I were standing near an active volcano and suddenly, livestock, large animals, birds, bats, whatever, started exiting the scene en masse and rapid choas, I'd probably get a little spooked.

[Paragon]

2 minutes ago, Windspeed said:

Low-frequency long period events and harmonic tremors aren't necessarily strong enough to be felt outside of 8 km or so from the source by humans unless magma is already exiting the system explosively. In other words, if you're feeling a low rumble, you're already in trouble. Typically, you need seismic equipment to detect a harmonic tremor.

As for animals, I'm not discrediting the phenomenon. I just don't know. Obviously, certain animals perceive sounds and vibrations humans do not always perceive or cannot perceive. I'm just not familiar enough with any science on the subject to state either way, especially when it comes to precursor activity leading up to an event.

I can say without hesitation that if I were standing near an active volcano and suddenly, livestock, large animals, birds, bats, whatever, started exiting the scene en masse and rapid choas, I'd probably get a little spooked.

https://www.livescience.com/15738-zoo-animals-sense-earthquake.html

 

This was the one I remembered- I think there were some videos showing this.

 

It did make people very uneasy.

 

People along the East Coast weren't the only ones to feel the 5.8-magnitude earthquake Tuesday, as zoo animals in Washington, D.C., let it be known they felt the vibrations, zoo officials said.

Some of the animals at the Smithsonian’s National Zoological Park even shouted alarm calls or ran up trees seconds before the rest of us felt the shaking.

 

About 5 to 10 seconds before Tuesday's quake, an orangutan named Kyle and a Western lowland gorilla named Kojo, abandoned their food and climbed to the top of the treelike structure in the Ape House exhibit.  

he prequake jitters are not uncommon among animals, with stories and even some science to back them up, suggesting some animals can sense the seismic waves before they do any Earth-shaking.

Animals go berserk

 

When the quake did hit, Mandara, a gorilla at the zoo, let out a shriek and collected her baby, Kibibi, before moving to the top of the tree structure. In a sign of extreme irritation, Iris, an orangutan, began belch-vocalizing just before the quake. She continued making this noise, indicating annoyance, following the quake as well. [Read: Can Animals Predict Earthquakes?]

Some of the zoo's small mammals seemed to have gotten the temblor memo even earlier. The red ruffed lemurs sounded an alarm call about 15 minutes before the quake and then again just after it occurred. And the poor black-and-rufous giant elephant shrew hid in its zoo home, refusing to come out for an afternoon snack.

Meanwhile, the snakes, including the poisonous copperheads and cottonmouths, which are typically inactive during daylight, writhed during the quake.

Some of the animals seemed to think a dip in the pool was in order: Just as zookeepers were feeding the beavers and a duck species called hooded mergansers, the quake struck. The ducks immediately jumped into the pool, while the beavers first stood on their hind legs before following suit.

Others huddled. The zoo's flock of 64 flamingoes gathered into a group just before the shaking and remained cozy during the quake. The zoo's lions were more grounded, standing up and facing the zoo building, which rattled during the earthquake, before settling down within minutes.

[Paragon]

Here's something about the Indonesian Tsunami

https://news.nationalgeographic.com/news/2005/01/0104_050104_tsunami_animals_2.html

 

The beach was one of the worst hit areas of the 500-square-mile (1,300-square-kilometer) wildlife reserve, which is home to a variety of animals, including elephants, leopards, and 130 species of birds.

Corea did not see any animal carcasses nor did the park personnel know of any, other than two water buffalos that had died, he said.

 

Along India's Cuddalore coast, where thousands of people perished, the Indo-Asian News service reported that buffaloes, goats, and dogs were found unharmed.

Flamingos that breed this time of year at the Point Calimere wildlife sanctuary in India flew to higher ground beforehand, the news service reported.

Strange Animal Behavior

Accounts of strange animal behavior have also started to surface.

About an hour before the tsunami hit, Corea said, people at Yala National Park observed three elephants running away from the Patanangala beach.

World Wildlife Fund, an organization that leads international efforts to protect endangered species and their habitats, has satellite collars on some of the elephants in the park.

A spokeswoman said they plan to track the elephants on that fateful day to verify whether they did move to higher ground. She doesn't know, though, when the satellite data will be downloaded and analyzed.

Corea, a Sri Lankan who emigrated to the United States 20 years ago, said two of his friends noticed unusual animal behavior before the tsunami.

One friend, in the southern Sri Lankan town of Dickwella, recalls bats frantically flying away just before the tsunami struck. Another friend, who lives on the coast near Galle, said his two dogs would not go for their daily run on the beach.

"They are usually excited to go on this outing," Corea said. But on this day they refused to go and most probably saved his life.

Alan Rabinowitz, director for science and exploration at the Bronx Zoo-based Wildlife Conservation Society in New York, says animals can sense impending danger by detecting subtle or abrupt shifts in the environment.

"Earthquakes bring vibrational changes on land and in water while storms cause electromagnetic changes in the atmosphere," he said. "Some animals have acute sense of hearing and smell that allow them to determine something coming towards them long before humans might know that something is there."

Did Humans Lose Their Sixth Sense?

At one time humans also had this sixth sense, Rabinowitz said, but lost the ability when it was no longer needed or used.

Joyce Poole is director of the Savanna Elephant Vocalization Project, which has its headquarters in Norway. She has worked with African elephants in Kenya for 25 years. She said the reports of Sri Lanka's elephants fleeing to higher ground didn't surprise her.

Research on both acoustic and seismic communication indicates that elephants could easily pick up vibrations generated from the massive earthquake-tsunami, she said.

Poole has also experienced this firsthand.

"I have been with elephants during two small tremors, and on both occasions the elephants ran in alarm several seconds before I felt the tremor," she said.

One of the world's most earthquake-prone countries is Japan, where devastation has taken countless lives and caused enormous damage to property. Researchers there have long studied animals in hopes of discovering what they hear or feel before the earth shakes. They hope that animals may be used as a prediction tool.

[Windspeed]

[Windspeed]

[wolfpackmet]

Yea the aerosols need to make it to the stratosphere.  We haven't seen anything significant since Pinatoba 1991.  Agung's last eruption the aerosols stayed in the Southern Hemisphere.  GISS aerosols  

[Windspeed]

Not good... Very intense harmonic tremor in progress. The kind that makes your stomach weak and your adrenaline jump.

[Maestrobjwa]

19 minutes ago, Windspeed said:

Not good... Very intense harmonic tremor in progress. The kind that makes your stomach weak and your adrenaline jump.
 

Ohhh boy...Is it wrong for me to have a strange case of excitement about this? Lol (Obviously I pray everyone makes it out safely if/when it finally erupts, but...just the months of anticipation, the amount of time since the last eruption, learning about volcano history for the first time...it's been quite the experience!)

[LithiaWx]

5 hours ago, Windspeed said:

Not good... Very intense harmonic tremor in progress. The kind that makes your stomach weak and your adrenaline jump.
 

Boom goes the dynamite this time perhaps?

[Windspeed]

Time-lapse before sunset:

 

 

[Windspeed]

Weak harmonic events are still evident but nothing like the intense signature that occurred between 4:00 and 8:00 UTC. That was by far the largest purely volcanic signature throughout the current episode of activity. That particular long period was reported as overscale by the PVMBG. Which essentially means the frequency was clipping beyond set levels of the seismograph. That was eye-opening, to put it mildly.

Keep in mind, once magma reaches nearto the surface rock, you do not need a strong signature for an ongoing eruption, especially once the pathway is open. However, when you do get signatures like earlier, they can be troublesome in that more magma is on the move from depth. Preceding a larger expulsion of material, I would have expected to see such a signal. Nevertheless, it looks like we are settling in for a long-duration event. I hope the intensity of the eruption does not exceed my worst expectations.

[Isotherm]

1 hour ago, Windspeed said:

Weak harmonic events are still evident but nothing like the intense signature that occurred between 4:00 and 8:00 UTC. That was by far the largest purely volcanic signature throughout the current episode of activity. That particular long period was reported as overscale by the PVMBG. Which essentially means the frequency was clipping beyond set levels of the seismograph. That was eye-opening, to put it mildly.

Keep in mind, once magma reaches nearto the surface rock, you do not need a strong signature for an ongoing eruption, especially once the pathway is open. However, when you do get signatures like earlier, they can be troublesome in that more magma is on the move from depth. Preceding a larger expulsion of material, I would have expected to see such a signal. Nevertheless, it looks like we are settling in for a long-duration event. I hope the intensity of the eruption does not exceed my worst expectations.

 

 

What are the factors that lead you to believe a long-duration event is more likely at this juncture?

[Windspeed]

What are the factors that lead you to believe a long-duration event is more likely at this juncture?

Keep in mind, this is only my unprofessional speculation. I am not a volcanologist. Even if I were, I would only focus on the information by those working for the Centre for Volcanology and Geological Hazard Mitigation (CVGHM) / Pusat Vulkanologi & Mitigasi Bencana Geologi (PVMBG), who are directly monitoring the situation in Bali.

 

Based on evidence of at least 150 million cubic meters of recharge; that we just experienced such a strong harmonic tremor; that a pathway is currently open in the conduit based on incandescence and fresh ash; that imagery of the eruptive column suggests multiple vents on the crater floor; all this leads me to believe Agung is only in the early phase of its eruptive cycle. I have not seen an official report yet, but the current column >2 days is probably still a mix of old material and fresh lava from multiple surface vents. On visual observations alone, the eruptive columns have not surpassed a size of medium or moderate volume. Based on the potential amount of new material, such exhalations could go on for weeks to months. As for the vents, it would be nice to have some drone footage to observe them. Hopefully that will become possible at some point.

 

Those vents may grow and even merge further breaking down the crater surface floor and increasing the eruptive rate, especially if the potential of new material reaches shallow rock. A much higher rate of ejection and velocity is a very real possibility. A violent eruption could release that material rapidly, of course. Additonally, a higher rate could also compromise the upper region of the cone's edifice. But I think it is more likely that activity waxes and wanes for weeks, even months, with periods of moderately strong exhalations. I am not saying we will see a single event exceed the '63 eruption. It is my hope no single paroxysmal event in this eruptive episode surpasses VEI-4. Anyone making such a prediction is being subjective.

 

Lastly, the possibility exists that the explositivity of the deeper magma could decrease with time as the ongoing eruption evolves and overall volatile gas potential declines. Agung's edifice didn't reach over 3,000 meters above sea level by only experiencing explosive plinian eruptions. It does go through periods of dome growth and lava flows. Though, at present, we don't have enough evidence to definitely know how this eruptive cycle will evolve, eventual dome and cone growth can't be ruled out. That could lead to years of ongoing effusive activity.

[Windspeed]

Here's a nice summary of Agung so far from the Volcano Group at the Earth Observatory of Singapore:

http://www.earthobservatory.sg/news/agung-volcano-bali-eruption-update

According to the CVGHM, Agung’s activity level is currently very high, and the probability of an even larger eruption is increasing. The intensity of such an eruption cannot be forecasted. It is particularly difficult to forecast the behaviour of Agung because of its small number of historical eruptions and the absence of geophysical monitoring data from these previous eruptions.

The only reference data available are from a sequence of earthquakes felt by the people around Agung in 1963, and again this year. Since the unrest began in mid-September, there has been a continuous increase in Agung’s volcanic activity.

The CVGHM has continuously and closely monitored all the changes in activity with a large variety of ground-based instruments and remote sensing techniques (e.g. seismicity, deformation, degassing, visual observations, and thermal data from CCTV, drones, and satellites.

According to the CVGHM and historical records, if an eruption similar to the one that occurred in 1963 were to occur, the hazards would range from volcanic bombs, to ash-fall, pyroclastic flows, lava flows, and lahars. An event similar to the one in 1963 (wherein the Volcanic Explosivity Index, VEI, was 5) could result in an eruption that would occur intermittently over several months.

[Windspeed]

Another strong harmonic tremor between 8 and 11 UTC, Nov. 29th, like on the 28th.

[Windspeed]

An Update on the Agung volcanic eruption in Indonesia contributed by Dr. Hutchison @ EGU Blogs: https://blogs.egu.eu/divisions/gmpv/

Of note:

The pattern of activity we have seen to date allows for a direct comparison with that observed during the first days of the 1963 eruption, as reported by Self and Rampino [2012]. Then, there were two days of felt seismic activity followed by explosive activity, associated with a lava emission which eventually produced a 7.5 km long lava flow (after 26 days). The explosive activity produced ash and incandescentmaterial that was ejected to 6 km above the craters. Pyroclastic flows, generated either from the collapsing front of the lava flows or the explosive activity, were visible running down canyons on the north and south flanks. After nearly a month of this activity the eruption ramped up to a significant explosion, generating a plume to  19-26 km altitude above sea level. A further tall eruption column was formed during an explosion ~2 months later, and then mild explosions and lahars continued for several months, before the eruption ended.

 

Comparing with the current activity, it appears that the 1963 eruption was a lot more energetic in its onset. The incandescent ash venting for some days now has not yet led to a more explosive phase and there is no sign yet of a lava flow. However, the transition could be such that pyroclastic flowsappear with little to no warning, hence we must stress the importance of adhering to the evacuation procedures. However, this could change quickly, and the transition could be such that pyroclastic flowsappear with insufficient time to escape for anyone within the evacuation zone. How the eruption will develop from here is hard to judge. The most likely evolution would be towards a lava effusion as in 1963, but there could be a sudden transition to explosive activity or, whilst lower probability, cessation of activity.

[Windspeed]

[Windspeed]

The Ministry of ESDM Geological Agency of Volcanology and Geological Hazard Mitigation released a detailed report about Mount Agung today. The wonderful Dr. Krippner translated. Posting below for posterity:

Quote

1/n * Monitoring Data Analysis *
-Visual-
After undergoing a volcanic earthquake swarm over the period Sept-Oct 2017, finally on 21 November 2017 at 17:05 WITA the phase of eruption of Mount Agung evolved to produce volcanic ash as high as 700 m above the peak.

2/n After the eruption, the next eruption occurred again on November 25, 2017 at 17:20 WITA with an ash plume height of 1500 m above the peak. On 26 and 27 November 2017 eruptions occurred with the ash column height reaching 3000 m above the peak.

3/n On 28 November 2017 the eruption produced an ash column reaching 4000 m above the peak. On November 29, 2017 the eruption produced an ash column height reaching 2000 m above the peak.

4/n At night, incl. tonight, there is incandescence that emanates from the crater. The observation of the incandescence above the crater is possible due to the presence of high-temperature lava in the crater. This is reflected in the ash/steam plumes causing it to be observed.

5/n Lahars have occurred & mainly flowed in the rivers in the Sthrn sector, incl. Tukad Yehsa, Tukad Sabuh & Tukad Beliaung & in the Nthrn sector in Tukad Bara. The lahars did not result in casualties, however, lahars have impacted several houses, roads and rice fields.

6/n
- Seismicity -

Earthquakes are still dominated by the occurrence of deep and shallow volcanic earthquakes. This indicates that there is still magma movement at depth. Currently the number of volcanic earthquakes is no longer as much as the period September-October 2017.

7/n This happens because the magma path to the surface is now more open. Therefore, although the number is not much, but it does not mean that volcanic activity has subsided.

8/n Continuous tremors with amplitudes over the background level, until overscale (beyond the capability of recording devices) continue to be recorded since November 28, 2017 to today (December 1, 2017). This indicates a high intensity of activity near the surface.

9/n Low-frequency earthquakes are recorded several times and this is related to the movement of Magmatic fluid to the surface.

10/n - Deformation -
GPS measurement results do not record a clear pattern of inflation ahead of the eruption. This is different from the pattern shown by GPS prior to the occurrence of swarms (sequence of volcanic earthquakes) in the period September-October 2017...

11/n
... whereas that GPS showed inflation of the body of Mount Agung [slight outward moving of the volcanic flanks] since August 2017 until mid-September 2017.

12/n The pattern shown by the tiltmeter measurements is in the form of inflation before eruption and deflation after eruption takes place.
[tiltmeter general info here: https://t.co/gjhw9XqUv7]

13/n - Geochemistry -
Lab test results of the volcanic ash produced by the opening eruption on November 21, 2017 show the existence of juvenile content (new magma material). Within the ash, older material from the 1963 eruption was also identified...

14/n
... Based on the results of this laboratory test, it can be concluded that the first eruption of Gunung Agung was phreatomagmatic. This eruption can occur when the new magma interacts with water in the aquifer system under the crater of Mount Agung.

15/n
Prior to the Nov 21, 2017 eruption, CO2 gas could be measured at high concentrations by the MultiGAS equipment flown by Drone. However, the SO2 gas concentration was not yet measurable. After the Nov 21, 2017 eruption, to this day...

16/n
... the concentration of SO2 gas is still consistently measured. Higher concentrations of SO2 was observed over the period of 26-27 November 2017, after which, the concentration of SO2 relatively decreased.

17/n - Remote Sensing Satellite -

Satellite data consistently records hotspots [higher heat output] on 27, 28 and 29 November 2017 with temperatures ranging from 286.6-298.8 +/- 6 degrees Celsius, with a maximum power of 97 megawatts.

18/n
Satellite data also indicate that the effusive eruption (lava flow to the surface) is still occurring within the crater.

19/n

This effusive eruption has implications for the addition of lava volume in the crater with an estimated current lava volume of about 20 million cubic meters, or one third of the total volume of the crater.

20/n * Conclusions*
Based on multi-parameter data analysis, it can be concluded that until now (December 1, 2017) volcanic activity of Agung is still high and still in the phase of eruption.

21/n
Therefore, the status of Agung is still at Level IV (Awas). Communities around Agung and climbers/visitors/travelers are urged to NOT climb Agung and not to engage in any activity within the Danger Zone...

22/n
... within the area of the Agung crater and in all areas within a radius of 8 km from the Agung crater, plus the sectoral expansion to the North-Northeast and Southeast-South-Southwest out to 10 km from the Crater of Mount Agung.

23/n
It is still safe to travel in Bali as long as you do not enter the above Danger Zone.

Ministry of ESDM
Geological Agency of Volcanology and Geological Hazard Mitigation
--END--
https://t.co/jC4a8Hjn0r