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    Erin

Volcano thread

Someone shared beautiful pictures on Facebook of Mount Ararat, taken in May, and it occurred to me that perhaps someone might not know that this Biblical mountain is an active volcano.

Here is its Global Volcanism Program page, too.
 
It's not just volcanologists who adore Etna :) :

 
Yes, Alaska DOES have active volcanoes though they haven't been troublesome lately.

Fortunately for Anchorage, something like this isn't likely to happen again any time soon, per the information statement issued late yesterday (AVO Spurr page), despite the appearance of a new crater lake.

1992 (aircraft noise is loud):



-------------------

2024:

ALASKA VOLCANO OBSERVATORY INFORMATION STATEMENT
U.S. Geological Survey
Wednesday, July 3, 2024, 3:42 PM AKDT (Wednesday, July 3, 2024, 23:42 UTC)
SPURR (VNUM #313040)
61°17'56" N 152°15'14" W, Summit Elevation 11070 ft (3374 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

New observations of a small lake in the summit crater of Mount Spurr support recent seismic and deformation data that indicate a possible minor intrusion of magma has occurred beneath the volcano over the last several months. While the formation of the lake is new, gas emissions remain low and seismic activity is declining, suggesting the probability of an eruption in the near future has not significantly increased. No surface changes have been observed at Crater Peak, the vent 2 miles (3 km) south of the summit associated with all historical eruptions.

The lake first appeared between May 15 and June 15, and was well documented during a June 23 overflight (avo.alaska.edu/image/view/195469) when it had an area of about 1 acre (3800 square meters). The last time a crater lake formed at the summit of Mount Spurr was during seismic unrest in 2004 that did not lead to an eruption.
The June 23 overflight also monitored gas emissions from the volcano and detected low levels of sulfur dioxide and carbon dioxide. The measured compositions are similar to background levels measured in previous years. Deep intrusion of magma is sometimes associated with anomalously high volcanic carbon dioxide emissions, but no such anomaly was detected during the overflight.

Seismic activity beneath Mount Spurr has been above normal levels since spring 2024, but starting on May 20, the degree of seismic unrest has declined and remains slightly elevated (avo.alaska.edu/image/view/195477). The occurrence of deeper (>12.4 miles or 20 km) low frequency earthquakes has been above background levels since spring 2024. A small amount of deformation, consistent with a shallow (less than 3 miles or 5 km depth) source of inflation, has been observed in GNSS data. Similar to the earthquake activity, the rate of deformation appears to be decreasing.

Mount Spurr is monitored by a local seismic network, GPS and infrasound sensors, and a webcam. Remote sensing data including satellite imagery, regional infrasound sensors, and lightning data are also used to detect potential eruptions at the volcano.



Mount Spurr volcano is an ice- and snow-covered stratovolcano located on the west side of Cook Inlet approximately 75 miles (120 km) west of Anchorage. The only known historical eruptions occurred in 1953 and 1992 from the Crater Peak flank vent located 2 miles (3.5 km) south of the summit of Mount Spurr. These eruptions were brief, explosive, and produced columns of ash that rose up to 65,000 feet (20 km)above sea level and deposited minor ashfall in south-central Alaska (up to ¼ inch or 6 mm). The last known eruption from the summit of Mount Spurr was more than 5,000 years ago. In 2004, Mount Spurr experienced an episode of increased seismicity, surface uplift, and heating that melted a large hole in the summit ice cap and generated debris flows. Primary hazards during future eruptions include far-traveled ash clouds, ash fall, pyroclastic flows, and lahars or mudflows that could inundate drainages all sides of the volcano, but primarily on the south and east flanks.



CONTACT INFORMATION:

Matt Haney, Scientist-in-Charge, USGS [email protected] (907) 786-7497
David Fee, Coordinating Scientist, UAFGI [email protected] (907) 378-5460

The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.
 
This happened several hours ago at Stromboli; the people are okay because they live on the other side of the island from the "Stair of Fire" (Sciara) that Stromboli's flows -- pyroclastic, lava, and landslide -- go down (you'll see that side towards the end of the video):



What does get to the people are tsunamis when the flows are big enough to displace lots of water (this one apparently wasn't).

Hazard here is complex, though, and since the volcano has been tetchy lately anyway and they've gone to Red Alert on this "lighthouse of the Mediterranean," it needed a post; hopefully, it won't progress into something calling for a thread.

Probably not -- Stromboli gets feisty every now and then, and landslides on the Sciara are always a concern, but this volcano typically stays on a fairly low level of activity. Heightened activity doesn't last very long.
 
Meanwhile, in Indonesia, the Sarah Connor of volcanoes ("Ibu" means "mother") continues its unusually intense activity -- fairly far from settlements, fortunately:

 
Etna has been in full drama-queen mode lately, first with quiet little shows that drew in fans to the Voragine crater (same one the volcanologists visited in the video a couple posts ago):



And then going all majestic (not without warning; no one was up there and settlements are way down on lower slopes where only plume fallout and the occasional flank eruption are a threat):



People love Etna because it never disappoints.

It's a very dangerous volcano, for all that.
 
Meanwhile, in California, a sleeping volcano snores a little bit:



 
About 3-1/2 At around midday local time, Stromboli had a paroxysmal eruption for the first time since 2019 (a different and more energetic event than the small summit crater collapse on July 4 that also triggered pyroclastic flows).

Per INGV (Facebook translation):

VOLCANIC ACTIVITY STATEMENT on 2024-07-11 12:46:59(UTC) -

#STROMBOLI.

The National Institute of Geophysics and Volcanology, #EthneoObservatory, informs that from the analysis of the images of the surveillance network cameras and by the INGV personnel in the field it is possible to observe that at around 12.07 UTC a paroxistic event occurred at the summite craters. Such activity has produced an #erruptivecolumn and a #pyroclasticflow along the Sciara del Fuoco. The flow has spread to the sea tens of meters from the
coastline. The long-sleeve phenomenon was exhausted around 12:10 UTC. From a seismic point of view, as of 12:07 UTC, all Stromboli stations have registered a seismic transient associated with a sequence of explosive events for a
total duration of about 8 minutes, the most energetic of which (12:08:50 UTC) is associated with the paroxistic event at summite craters. The average magnitude of the tremor has reached a very high
level in correlation with the paroxistic event followed by a rapid decline until it currently reaches the average level. Regarding permanent deformation control networks, sensors in clinometric stations and GNSS show no significant variation.
Click to expand...

Here is one of the images that INGV field workers got of this event:



The summit has been closed to tourists for a while, so casualties up there are unlikely. INGV workers, hopefully, had enough warning and professional caution to avoid harm.

From news reports, I understand that the island's people, on the other side from the Sciara, haven't evacuated. The beaches, however, were closed and I hope the pyroclastic flow didn't generate a large tsunami.

Stromboli has these paroxysms every now and then, as well as the lesser explosiveness it was showing last week.

Volcanologists weren't sure what was happening with the recent lava flows (I blogged about that), so maybe there is still a question of whether the usual post-paroxysm calm will return now, along with eventual resumption of the typical Strombolian summit activity, or what. Time will tell.
 
Last edited:
Good news from LGS (Facebook translation): "...The event was detected by the Early-Warning Parossisma alert system at
12:06:20 UTC about 3 minutes in
advance (Figure 5 and 6) and was
preceded by about 50 minutes
(11:18:06 UTC) by a clear
deformative signal that allowed to
pre-alert operational staff to COA
and i Researchers and technicians
on the slopes of the volcano while it
was carrying out maintenance at the stations.

"The explosion generated pyroclastic flows along the Sciara of Fire reaching the sea (Figure 7) generated a tsunami with a wave of about 50 cm (peak-peak), below the warning thresholds..."

They also got amazing video footage of the start.
 
Ever wonder what a volcano's summit looks like right after a big eruption?

As soon as Etna's Voragine crater calmed down, the volcanologists went up (risky but back at HQ, all eyes are glued on the volcano's vital signs just in case of impending trouble -- these people know Etna better than many of us know our closest friends).

This was uploaded an hour ago -- the scenery sure looks different from how it was in the last video!



Google translation of the YouTube note: "The surveys carried out by Alessandro Bonforte and colleagues of the INGV Osservatorio Etneo on the northwestern edge of Etna's summit craters, to acquire ground control points with precision GNSS, useful for constraining and increasing the accuracy of digital terrain models ( DEM), are an opportunity to show us the current state of the Bocca Nuova, filled (to the point of overflowing) by the lava erupted from the lava fountains at the adjacent Voragine crater on 4 and 7 July."

Bocca Nuova until now, was one of Etna's eruptive craters.
 
Per INGV, Voragine crater has started with strombolian-style activity again. This news source, Local Team, just started live-streaming the action.

At the moment, fountaining is low (for Etna), but this is a volcanic drama queen and it might get spectacular again.

Speaking of Stromboli -- the type location for sparkly, bubble-bursting eruptions -- it does seem to have calmed down after the paroxysm. INGV reportedly went up there today and replaced destroyed monitoring equipment.

The flank lava flows stopped and occasional, small ash emissions occur at the summit area. Oddly enough, at the moment there are no strombolian eruptions at Stromboli!
 
TornadoFan said:
Hydrothermal explosion at Yellowstone.
Click to expand...

I'm looking for more information on USGS sites (update: here it is), but this news article confirms a small hydrothermal explosion in the Biscuit Basin today and quotes the USGS as saying:

Monitoring data show no changes in the Yellowstone region. Today’s explosion does not reflect activity within volcanic system, which remains at normal background levels of activity. Hydrothermal explosions like that of today are not a sign of impending volcanic eruptions, and they are not caused by magma rising towards the surface.
Click to expand...

Here is a YVO article from 2018 on these events, and one of the examples is Biscuit Basin.
 
This whole thread is good; it basically repeats what is in the information statement but they also provide a graphic showing destructive potential of various events. Hydrothermal explosions are the smallest (and most common hazard), and caldera-forming eruptions, of course, are the worst (and least likely -- incidentally, while everything magmatic is quiet there now, I've read from a couple volcanological sources that if and when Yellowstone does fire up in our lifetime, it will be with another "normal" lava flow like those during its most recent activity periods):

 
Recap from USGS on Facebook, about 14 hours ago -- glad no one was hurt!

Here's a recap of today's event at Yellowstone:

A little before 10 AM, there was an
explosion of steam, hot water, and rocks (a hydrothermal explosion) near Black Diamond Pool, a 118-ft-long (36 m) hot spring in Biscuit Basin in Yellowstone National Park.

No one was injured and the boardwalk was damaged. The Biscuit Basin area is closed
temporarily as the Yellowstone National Park staff assess conditions.

In Yellowstone, hydrothermal explosions are violent and dramatic events that can occur with little-to-no-warning. They occur in shallow reservoirs of fluids are at or near the boiling point. The fluids can flash
to steam if the pressure suddenly drops, hurling boiling water, steam, mud, and rock fragments into the air.

These are not volcanic eruptions. In fact, the deeper magmatic system appears to be unaffected by these spectacular explosions within the hydrothermal system. No changes have been observed in Yellowstone volcano monitoring data as a result of the hydrothermal explosion and
Yellowstone remains at normal,
background levels of activity.

Small hydrothermal explosions happen almost annually in Yellowstone National Park—like a small crater in Norris Geyser
Basin that formed during a minor
hydrothermal explosion on April 15, 2024. Another recent and notable hydrothermal explosion occurred in 1989 at Porkchop Geyser in Norris Geyser Basin. The remains of this explosion are still clearly visible
today as jumbled chunks of rock 15 ft (5 m) across Porkchop's central spring. In the 1880s and early 1890s, a series of powerful hydrothermal explosions and geyser eruptions occurred at Excelsior
Geyser in the Midway Geyser Basin. Some of the explosions hurled large rocks as far as 50 ft (15 m).

The largest hydrothermal-explosion crater documented in the world is along the north edge of Yellowstone Lake in an embayment known as Mary Bay. This 1.5-mile (2.6 km)-diameter crater formed about 13,800 years ago and may have had
several separate explosions in a short time interval.

Yellowstone National Park staff are
familiar with hydrothermal hazards and are assessing the situation now with more information to come. It may take a little time for the hydrothermal system in the area to reach a new equilibrium and
smaller events are possible. If you plan on visiting the Park, check for closures.

Be safe.
Click to expand...
 
They talked about Mount St. Helens a bit in this week's CVO update, though its activity is still in background levels:

...Past Week Observations: Mount St. Helens continues to experience slightly heightened seismicity than typical of recent years, with 4 located earthquakes in the last week, and 479 since Feb 1 when the current increase in seismicity began. The largest earthquake over the past week was a magnitude 0.8, with the largest since Feb 1 a magnitude 2.0. The average depth of earthquakes at Mount St. Helens last week was 4.6 miles below the crater, compared to an average depth of 3.9 since Feb 1. Although this level of seismicity is elevated compared to the last several years at Mount St. Helens, it is still considered within the background range and does not suggest an imminent eruption. No changes have been detected in ground deformation, volcanic gas, or thermal emissions at the volcano.

Small earthquakes were also detected this week at Mount Rainier, Mount Adams, and Crater Lake. All monitoring data are consistent with background activity levels in the Cascades Range.

Field crews performed station
maintenance this week at Mt. Rainier and Mt. Hood.


Click to expand...
 
Glacial outburst flood is happening at Katla. Per this report (autotranslated), it threatens some infrastructure and they have closed the local section of the Ring Road, but it probably is geothermal rather than a sign of impending eruption.

Some info links (the VAAC probably won't be needed):

 
Per Visir (autotranslated):

"It happens every year that some boilers empty, but the events are rarely big. The last major event was in Skálm 2011, which lasted for several hours. The greatest danger from this is near the glacier spurs, where the glacial water rages out," says Einar Hjörleifsson, a natural hazard expert at the Norwegian Meteorological Agency.

He says this can be accompanied by high levels of gas pollution, and it can be dangerous for people to stay in the depressions in the landscape near the glacier spurs where the gas collects. The greatest concern is for tourists at Katlujökull on the east side of Mýrdalsjökull and Emstrur.
Click to expand...

No videos found yet. They do very close monitoring of Katla because of this hazard and the presence nearby of inhabited lowland areas and I'm sure they know exactly what's going on here.
 
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