Welcome to DU! The truly grassroots left-of-center political community where regular people, not algorithms, drive the discussions and set the standards. Join the community: Create a free account Support DU (and get rid of ads!): Become a Star Member All Forums Issue Forums Culture Forums Alliance Forums Region Forums Support Forums Help & Search

ruet

(10,035 posts)
Thu Sep 16, 2021, 09:16 AM Sep 2021

East Coasters. Keep An Eye On La Palma

Have a go bag ready. I'm not a superstitious person and would never post ANYTHING like this but I've have a bad feeling about this for a few days that I just can't shake. I'd happily be wrong.

Authorities warn of possible volcanic eruption on Canary Island of La Palma

The last eruption in La Palma took place in October 1971, when the Teneguía volcano spewed out lava for more than three weeks after a crack appeared in the south of the island. The situation remained calm until 2017, when seismic activity resumed. In the past few days, this activity has intensified with constant small tremors, known as an earthquake swarm, recorded a few kilometers from Teneguía in the Cumbre Vieja area, southeast of the island.

This earthquake swarm began on September 11, and since then, more than 4,200 tremors have been detected. Nearly all have been of small magnitude, but on Wednesday there were four that measured more than 3 on the Richter scale. What’s more, the tremors are also becoming closer to the surface, which indicates that magma is looking to escape. While the first earthquakes were recorded at more than 20 kilometers below the surface, on Wednesday, they hit at a depth of between six and eight kilometers. Indeed 20 tremors were recorded at just three kilometers below the surface. Another sign of the pressure is that, in the area of the earthquake swarm, the island has swelled six centimeters – 4.5 centimeters on Wednesday alone.

Luca D’Auria, the head of the Volcano Monitoring Department at the Canary Islands Volcano Institute (Involcan), said that, based on what is known about the geological history of La Palma, “magma builds up in an area that is five kilometers below the surface before entering into an eruption.” “What’s most likely is that the magma has found a way toward the surface and it is very likely that it will end up reaching it,” he explained. According to D’Auria, the situation is evolving “very quickly” – faster than what was recorded in El Hierro in 2011, when earthquake swarms took place for weeks before the eruption. Although the expert admitted it could “amount to nothing,” he argued that it was likely that an eruption will happen in the areas being hit by earthquakes, “but we don’t know yet.”


Spain holiday hotspot risks volcano eruption - yellow warning issued after 100s of tremors

The Canary Islands Government has activated the Special Plan for Civil Protection and Attention to Volcanic Risk Emergencies (PEVOLCA) in the Cumbre Vieja area (La Palma) due to the increase in seismic activity registered in recent days.

As reported by the Spanish Ministry of Public Administrations, Justice and Security, the decision has been adopted by the Scientific Committee of PEVOLCA convened this Monday to assess the situation.

Specifically, the Alert Plan has been activated for Fuencaliente, Los Llanos de Aridane, El Paso and Mazo, resulting in the change of the traffic light from green to yellow for these municipalities.

Officials say the “highest levels of Helium-3 detected in 30 years” in the volcanic ridge was a detonator.


Earthquakes continue, becoming shallower

The volcanic-seismic crisis continues to evolve. During the past 24 hours, earthquakes have been moving westwards and become shallower, the National Geographic Institute (IGN) reported.
This is likely reflecting continued magma intrusion and migration under the surface, supported also by continued deformation of the surface in the same area as the quakes. In places, the ground has been uplifted by 1.5 cm (almost one inch) already. The likelihood of an eruption has thus increased and the situation is being followed closely, although it is still far from certain whether it will or not result in a new eruption of the volcano.




There is a Tsunami risk to the eastern seaboard associated with the collapse of Teneguía and Cumbre Vieja into the Atlantic.



Cumbre Vieja tsunami hazard

The island of La Palma in the Canary Islands is at risk of undergoing a large landslide, which could cause a tsunami in the Atlantic Ocean. Volcanic islands and volcanoes on land frequently undergo large landslides/collapses, which have been documented in Hawaii for example. A recent example is Anak Krakatau, which collapsed to cause the 2018 Sunda Strait tsunami, claiming hundreds of lives.

Steven N. Ward and Simon Day in a 2001 research article proposed that a Holocene change in the eruptive activity of Cumbre Vieja volcano and a fracture on the volcano that formed during an eruption in 1949 may be the prelude to a giant collapse. They estimated that such a collapse could cause tsunamis across the entire North Atlantic and severely impact countries as far away as North America. Later research has debated whether the tsunami would still have a significant size far away from La Palma and whether the collapse is likely to take place in a single failure, with evidence indicating that most collapses in the Canary Islands took place as multistage events that are not as effective at creating tsunamis.


Cumbre Vieja Volcano -- Potential collapse and tsunami at La Palma, Canary Islands

Geological evidence suggests that during a future eruption, Cumbre Vieja Volcano on the Island of La Palma may experience a catastrophic failure of its west flank, drop- ping 150 to 500 km 3 of rock into the sea. Using a geologi- cally reasonable estimate of landslide motion, we model tsu- nami waves produced by such a collapse. Waves generated by the run-out of a 500 km 3 (150 km 3) slide block at 100 m/s could transit the entire Atlantic Basin and arrive on the coasts of the Americas with 10-25 m (3-8 m) heigh


Flank Collapse of the Cumbre Vieja Volcano (Canary Islands)

At 4 hours 20 min after the event, the tsunami westward moving wavetrain
has propagated about to the mid-Atlantic ridge (Figure 6) and now has a significantly
reduced leading wave, on the order of 6 m height. At 7 hours 20 min after the event,
the tsunami leading wave approaches the upper US East Coast continental shelf
break, with a leading wave on the order of 4 to 8 m (Figure 7).
Time series of tsunami elevation computed at the 6 reference stations (Table
2, Figure 7) are shown in Figure 8. Based on these fairly widely spaced results, and
keeping in mind these are still simulations in a 1’ grid, which is not fine enough to
capture all coastal wave transformations, the largest impact seems to be offshore of
Delaware.


Build A Kit
19 replies = new reply since forum marked as read
Highlight: NoneDon't highlight anything 5 newestHighlight 5 most recent replies
East Coasters. Keep An Eye On La Palma (Original Post) ruet Sep 2021 OP
OMG ... Lovie777 Sep 2021 #1
This Was Posted As I Composed The OP ruet Sep 2021 #3
Ay carumba! Champp Sep 2021 #2
The entire US East Coast JustAnotherGen Sep 2021 #4
... ruet Sep 2021 #5
Yikes! dhol82 Sep 2021 #6
jiminy h christmas JustAnotherGen Sep 2021 #8
Oh my Sherman A1 Sep 2021 #7
"No signs of imminent eruption, we cannot make a short-term prediction" Shanti Shanti Shanti Sep 2021 #9
No Harm In Being Informed. ruet Sep 2021 #10
I'm still waiting for the New Madrid fault to crack open at the same time Yellowstone blows up Shanti Shanti Shanti Sep 2021 #11
Your fifth source has a confusing measurement csziggy Sep 2021 #12
Eruption Has Begun. ruet Sep 2021 #13
Yep, it's doing it all right ornotna Sep 2021 #14
More updates malaise Sep 2021 #15
Unfortunately ornotna Sep 2021 #17
First thing I noticed malaise Sep 2021 #18
First thing I noticed malaise Sep 2021 #19
This message was self-deleted by its author malaise Sep 2021 #16

ruet

(10,035 posts)
3. This Was Posted As I Composed The OP
Thu Sep 16, 2021, 09:28 AM
Sep 2021
La Palma, Canary Islands: seismic crisis Sep 2021 - updates

The earthquake swarm has slowed down significantly over the past 24 hours, but it is too early to draw conclusions as to whether the crisis might soon be ending or whether it will pick up again in intensity.
Seismic activity continued to migrate slightly to the northwest and quakes were mostly at depths of around 8 km, although there were also 20 quakes at only 1-3 km to the surface. The maximum accumulated deformation reached about 6 cm by yesterday, the National Geographic Institute (IGN) reported. The rate of deformation has decreased, suggesting that the recent pulse of new magma intrusion might be over.
Since the start of the earthquake swarm, IGN has recorded more than 4200 quakes, of which 920 were strong enough to be located.

ruet

(10,035 posts)
5. ...
Thu Sep 16, 2021, 09:55 AM
Sep 2021


Tsunami surface elevation (color scale in meter) computed with FUNWAVE
in the 1’ spherical grid, at 7h 20 min after the start of the CVV event (450 km3 extreme
flank collapse scenario). [Numbers mark stations where time series are computed.]
 

Shanti Shanti Shanti

(12,047 posts)
9. "No signs of imminent eruption, we cannot make a short-term prediction"
Thu Sep 16, 2021, 01:32 PM
Sep 2021

Call me in 25 years, disaster predictions are a dime a dozen

And there's no place to run to on the east coast if a 100 meter tsunami is created by the island cracking off and crashing into the sea.

Carry on

ruet

(10,035 posts)
10. No Harm In Being Informed.
Thu Sep 16, 2021, 01:59 PM
Sep 2021

Also, not a 100m high tsunami by the time it reaches land. The graphic I posted from the NWS, which is more optimistic and said to be more accurate than the Ward/Day paper, shows an 8M wave height on the Eastern Seaboard. That's very large but it's not 100M.

Spanish officials fear volcanic eruption on La Palma

"What's most likely is that the magma has found a way toward the surface and it is very likely that it will end up reaching it," said Luca D'Auria, the head of the Volcano Monitoring Department at the Canary Islands Volcano Institute (Involcan).
 

Shanti Shanti Shanti

(12,047 posts)
11. I'm still waiting for the New Madrid fault to crack open at the same time Yellowstone blows up
Thu Sep 16, 2021, 03:07 PM
Sep 2021

They should make a movie

csziggy

(34,119 posts)
12. Your fifth source has a confusing measurement
Thu Sep 16, 2021, 03:23 PM
Sep 2021

It says: "on the coasts of the Americas with 10-25 m (3-8 m) height"

I believe they mean 10-25 feet (3-8 m) since 3 meters is 9.84252 and 8 meters is 26.2467 feet.

As we've seen with storm surge from hurricanes, ten feet causes significant damage and 25 (or 26) feet catastrophic.

ruet

(10,035 posts)
13. Eruption Has Begun.
Sun Sep 19, 2021, 12:16 PM
Sep 2021

Don't sleep on this volcano. Stay alert.

https://www.theguardian.com/world/2021/sep/19/spanish-canary-island-volcano-erupts-after-weeks-of-earthquakes

A volcano has erupted on the Spanish Canary Island of La Palma after a week of building seismic activity.

A huge column of smoke rose up after the eruption at 3.15 pm local time (14:15 GMT) in the Cumbre Vieja national park in the south of the island, according to the Canary Islands government.

Just before, authorities evacuated about 40 people with mobility problems and farm animals from the villages around the volcano.

Soldiers were deployed to help with the evacuation, the defence ministry said, and it is expected that more people will be evacuated from surrounding towns.

Before the eruption scientists had recorded a series of earthquakes reaching 3.8 magnitude in the national park, according to the Spanish National Geographical Institute (ING).

The earliest recorded volcanic eruption in La Palma took place in 1430, according to the ING. In the last eruption in 1971, one man was killed when he took photographs near the lava flows but no property was damaged.



ornotna

(10,763 posts)
14. Yep, it's doing it all right
Sun Sep 19, 2021, 04:59 PM
Sep 2021

Live links here





edit to add this feed. This one is panning around showing the destruction.

Response to ornotna (Reply #14)

Latest Discussions»General Discussion»East Coasters. Keep An Ey...