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Potential Disaster in the Making 10

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phamENG

phamENG

Structural
Feb 6, 2015
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Cumbre Vieja, a volcano on La Palma in the Canaries, just erupted a couple of hours ago. National Geographic did an episode on it as part of a 'Disaster Earth' series a few years ago. Essentially, there's evidence of a massive landslide on the island a few hundred millennia ago, the likes of which would have formed a tsunami large enough to hit the east coast of the US. A recent earthquake seems to have restarted the process and formed a large fissure along the island.

Here's to hoping it doesn't move any more....
 
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Welcome home.

Overnight seismic activity has been reported to be from a depth of 29km. Very deep, as previous activity has been at half or less that depth. It could be a sign that there is still more to come. They will continue to monitor for signs that additional magna may be making its way up to the surface.

I checked the temperature loss data for a lava tube.
1/2 meter is strong and is[flame][curse] sufficiently insulated to permit a quick measurement.
skylight1_large.jpg


Oh, there's a wiki for lava tubes ... "Lava tubes can be up to 14–15 metres (46–49 ft) wide, though are often narrower, and run anywhere from 1–15 metres (3 ft 3 in–49 ft 3 in) below the surface. Lava tubes can also be extremely long; one tube from the Mauna Loa 1859 flow enters the ocean about 50 kilometers (31 mi) from its eruption point, and the Cueva del Viento (Cave of the winds). 10 km from me.) system on Teide, Tenerife island, is over 18 kilometers (11 mi) long, due to extensive braided maze areas at the upper zones of the system. "
La-Cueva-del-Viento-interior-50-2-400x516.jpg
 
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Can you visit the Cueva del Viento ?
Can't remember hearing or seeing anything about it when we where on Tenerife.

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein
 
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Yes, you can visit the lava tube. About 500m is open to the public. We took our geologist PhD friend there when he came to visit last year. The short easy hike into the Canary pine forest to reach the entrance is also nice.

Several more earthquakes last night at 13 and 29km depths, one 3.8
The end is not in sight.

I was also surprised myself that the lava only loses 1"/km. Staying in the high temperature-low viscosity region keeps it moving so fast that it has no time to dissipate its heat. We use the same technique to move heavy and wax laden crude oils. Sometimes with only the burial depth of the soil providing insulation, sometimes using additional insulation, depending on the oil's solidification or wax deposition temperatures. You need high pressure and heat to 80°C to move it until the soil gets warm, but after a week of liquid flowing inside a soft oil core adhering to the pipe wall you eventually get it all liquefied and can half the pressure as the flow rate doubles. Pumps were arranged to change from series to parallel configurations. The Orinoco heavy crude would reach maximum flow at the lowest operating pressure range after about 3wks. A 24" diameter pipe with no insulation. After thermal stabilisation, we would lose 0.2°C/km over 200km pipeline starting at 75°C and arriving at the refinery at 35°.
 
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3 to 4 feet of dirt is pretty good insulation. It's been a long time ago, but those are the numbers I think I remember. Should I run the simulation again???

It's been running 25yrs with numbers very similar to those, if not exactly so.
 
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Speaking about lava tubes, I just this thermal image of the lava field.
Would the tubes appear to be hotter or cooler in the image? I suspect hotter than their surroundings, but I'm not sure. The hotter lines might be surface channels.

Screenshot_20211006-213006_Brave_gehr9s.jpg
 
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Things have more or less calmed down. The eruption is "maturing", meaning less explosive and a more constant lava flows. Flows are remaining within established surface channels and two pipelines.

The vulcanologists say that there are two independent magma supply pipes, one "Hawaiian", with hot, lighter lava that supplies the white smoking vent, the other Strombolian, heavier more viscous lava with the more explosive characteristic that supplies the black smoking vent, which has reduced its explosivity ... at least for now anyway.

Winds have changed, becoming more southerly, and ash blowing to the NNE again has closed the airport.
SO2 levels are increasing.

If the SO2 drops, it might be time for a quick visit.
 
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Below is a graph from the Kilauea volcano in HI that shows the number of EQ/month over the last five years. You can see the sharp increase during it's spectacular activity in 2018. Any plots like this for Cumbre Vieja?
eq1_adpqi0.jpg
 
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I have not seen any public rendering of the quakes history, but I am sure at least 10 of the army of seismologists and vulcanologists over here are watching that. There is an earthquake registry website that probably has it, but I'd filter it for > 2.5 before trying to download. They have reported as many as 5000 total in 24h, but most are totally impreceptible to anything but the most sensitive instruments. 50 events were registered within the last 24. More data might be published on social media which I have not seen. I am antisocialmedia, so don't have a clue what they put there.

It is also believed that high SO2 emission levels is a signal of a longer term event as well. That's still going relatively strong.

Another is landmass vertical displacement. That's up by 10cm over the general vicinity.

Some lava has jumped the channel and is now paralleling the south side setting some new structures on fire there.

I can't decide what the thermal signature of the tubes should look like. As you say, there's some logic for darker, or lighter too, if they are warmer than the adjacent lava to the tube's side. Losing only 1°/km, the tubes must be relatively hot in comparison to that, but they may also be deeper. 3 to 10m below the surface.
 
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Still think the optical part of it is fascinating and mesmerizing..

0_j2vuag.jpg


“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein
 
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