Nevado del Ruiz

[bjdeming]

This is basically just typical news of a volcano's status being raised from Yellow to Orange, but it is more than a typical volcano to the people of Colombia.

That's why I thought it deserved a thread of its own. For details, there's my blog post today and links therein.

In brief, Colombia has a lot of volcanoes but intensive monitoring began only after lahars during a small eruption of Nevado del Ruiz wiped out the town of Armero and its 20,000+ residents in 1985.

That horrible tragedy also helped kickstart the UN International Decade of Natural Disaster Risk Reduction and IAVCEI's Decade Volcano program.

Then, Galeras volcano stirred. The nation was still reeling from Armero, and the response at all levels to Galeras was warped by sensationalism and lots of understandable but unhelpful emotional responses from many officials.

Time has passed; people have healed (or not); and lessons have been learned.

Ruiz began low-level eruptions in 2014 and continues. This past week, volcanologists detected a change in behavior and raised the alert level to Orange, just in case.

They also issued a statement that is remarkably clear and detailed. It's good public outreach anyway but especially so in the light of those two past events.

That's also why I'm sharing this : because of their accompanying request to "fight the disinformation."

As of this morning, Ruiz remains at baseline.

 

[bjdeming]

This morning, they issued an extra bulletin: the alert level is unchanged; there are stilll many thousands of quakes, both rock-fracturing and from fluid movement.

I've seen in the news that at least some of the jurisdictions are setting a 15-km exclusion zone. That's a good move and would be done at any volcano showing these signs.

That glacier is the problem -- it could melt very quickly IF there's an eruption.

Still an "if" but Ruiz does show worrisome signs. Glad they've got it instrumented now.

With only a few decades of observations, though, it doesn't give much of a baseline for comparison now.

 

[bjdeming]

The situation continues at Orange level, with news reports saying that up to around 2,700 families may be evacuated.

Here's today's SGC bulletin, as well as a nice public outreach tweet by another government agency. It's in Spanish, but the images convey the general idea -- protect yourself and your community -- very well:



We in the US can follow this as training for eventual emergencies at ice/snow-covered volcanoes in places like California...



...and Washington.






Of note, that's a year old; Glacier Peak is getting more instrumentation.

 

[bjdeming]

Put the Shiveluch post here by mistake, sorry!

Nevado del Ruiz's activity has changed, though it is still at Orange alert level. The rock-breaking seismicity has dropped, but seismicity from fluid movement is increasing and sulfur emissions are rising.

It sounds to this layperson that ascending magma is at a shallow depth now, and its heat is disturbing the summit hydrothermal field (per an April 10th press conference with SGC).

It could still stop before erupting, but with magma so shallow, I wonder if magmatic gases are exsolving, too. Right now the conduit is apparently open, with almost continuous minor ash emission (Ruiz has been doing that intermittent, low-level stuff since 2012), but if and when that isn't enough to release gas and steam pressure, watch out.

 

[bjdeming]

In case anyone reading this is or might be in the area: UNGRD evacuation routes. (Spanish)

Am posting SGC updates and other info daily.

It's still Orange, but in today's update the volcanologists mention seismicity in the crater lava dome, as well as crater thermal areas.

If that dome goes, things might happen very quickly, since what's likely ascending magma is only about 3 km and at fairly shallow depth (sideways transport here, most of the way, not vertical).

Or it could just stop, which I hope is the case.

But am not betting on it.

 

[bjdeming]

In case anyone reading this is or might be in the area: UNGRD evacuation routes. (Spanish)

Here's an online article today that highlights responses in the places most at risk. It just reports the facts but also uses a graphic to show the distance between each place and the volcano, and it includes a picture, without comment, of the 1985 lahar (now solid rock).

Very effective to keep minds focused on a deadly threat -- lahars and, perhaps, pyroclastic flows -- that hasn't materialized yet but happens so fast that the best protection is to not be there when it arrives.

This being the Andes, one of those places must have a heliport to evacuate, which is awesome BUT can aircraft of any kind function so close to what might turn out to be a plinian-style eruption?

By the way, they report that livestock care and protection are issues in some places. This also came up on Java in 2010 when Merapi had its VEI 4 blast.

And I recall that here in Corvallis, during the Labor Day wildfires, folks from the valley transported to and housed livestock at the fairgrounds.

It's a facet of natural hazard management that many of us who aren't connected so closely to the land usually overlook.

 

[bjdeming]

Per Twitter translation: "Today from @ungrd together with @COL_EJERCITO , we held a disaster response interoperability workshop between the armies of the Republic of Colombia and the United States of America."

The SC Guard is in it, too.




This is a big deal. On the civilian side, am guessing VDAP is involved, and various US and international volcano observatory crisis response teams. I wonder what the satellite coverage is.

 

[bjdeming]

Colombia has gotten some heavy precipitation recently, and Nereidas and Guali river drainages are flooded on the SGC's Ruiz webcams.

There's undoubtedly ash in there, but (layperson opinion) I don't think it's a lahar. Yet. Looks like water. (Update: It was; the crest has passed now and the rivers have quickly gone back within channels; lahars modify topography.)

John Londoño, SGC, had an interesting interview with El Tiempo yesterday. Heat signatures in the crater could be (and probably are) seen with MODIS, but I don't see Ruiz (a little north of Bogota), on the MODVOLC website.

From that El Tiempo story (via Google Translate):

However, in the case that it was a big eruption, which is what we are anticipating and for which we change the level to orange, (because he has made many eruptions, hundreds of tiny eruptions every day, but they are minor eruptions) , we would be talking about a typical eruption like the ones that occurred in 1985 and 1989.

It is more or less what we would expect. But absolutely no one can say that it is bigger than 85, but seeing the characteristics and behavior of the volcano, hopefully it will not make a bigger one.

Per the GVP, the November 1985 event that killed so many people was part of a VEI 3 eruption. The last VEI 4 they list was in 1595.

For comparison, Mt. St. Helens 1980 was plinian and VEI 5: Pinatubo 1991 was plinian and VEI 6.

Volcano Discovery has a webcam/satellite imagery/seimicity Ruiz portal. The webcam links are out of date and broken, but you can access SGC's helicorder page and the appropriate Sentinel Hub EO image through it.

 

[bjdeming]

The elephant in the room. One of the districts near Ruiz is mentioned (Cauca) but not specific locations.

 

[bjdeming]

Nevado del Ruiz this morning: "Hmmm--think I'll punch the sky."



Still ORANGE, still rock'n'rolling.

 

[bjdeming]

As far as I can tell from checking national police and civil defense feeds on Twitter, these evacuations aren't mandatory yet, but it's the strongest wording I've seen from UNGRD yet. I've been following the SGC reports, too, and overall, if I were in those high-risk areas near Arenas Crater I would leave right now, and farther downslope, would do a lahar evac preparation drill at the very least (sirens can't always be heard in the mountains and cell service isn't totally reliable).

Check the graphic at their link too, if you're in the area or know someone there. It's still ORANGE, but this might be a good time to get as far away from from Nevado del Ruiz as you can, despite the holiday weekend.

Hope that advice isn't needed.

Emphasis added:

In the case of the communities that are located in the zone with high threat and within the perimeter of 0 to 15 kilometers from the Arenas del Nevado del Ruiz crater, the entity recommends an immediate evacuation in the places indicated by the municipal management councils of the disaster risk, given that the population located in this area would only have an evacuation time of approximately less than one hour.

In this sense, the UNGRD verified together with the entities of the SNGRD and the municipal authorities that some sectors of 19 villages located in the municipalities of Herveo, Casabianca, Villahermosa and Murillo in the department of Tolima; eight in the municipality of Villamaría in Caldas and one in Santa Rosa de Cabal, Risaralda, are within the perimeter and must be evacuated preventively, according to the map provided by the Colombian Geological Service (SGC).

On the other hand, the populations that are in high threat located at distances greater than 15 kilometers from the Arenas crater should take into account that the flow of lahars could move along the Gualí River from its source to the mouth of the Magdalena River and would involve to the municipalities of Herveo, Fresno, Mariquita, Honda, Falán Palocabildo and Casabianca in Tolima, as well as the municipality of Guaduas, in the department of Cundinamarca.

In addition, the municipalities of Casabianca, Villahermosa, Murillo, Líbano, Lérida, Ambalema, Armero and Honda in Tolima are at risk due to the passage of the Azufrado river and the Lagunilla river from its source to its discharge into the Magdalena river, while the Recio river would cause damages as it crosses the municipalities of Murillo, Líbano, Lérida, Venadillo and Ambalema in Tolima, and the Claro and Chinchiná rivers would affect Manizales and the Caldas municipalities of Anserma, Neira, Palestina, Chinchiná and Villamaría.

It is worth noting that the municipalities that are in high threat due to lahar flows must monitor and follow up in the field, update the status of secondary and tertiary roads considered evacuation routes, carry out evacuation drills with the community, review and adjust the emergency response strategy and strengthen early warning systems.

Finally, the UNGRD reiterates to the emergency operating entities that they update the map of actors and the call chain and urges the authorities of the departments to activate their early warning systems, strengthen the telecommunications and mass dissemination systems through loudspeaker, as well as alerts that facilitate timely notice to the communities located in these areas of the country.

 

[bjdeming]

As for graphics, while the main thing AFAIC is that SGC wrote in their update this morning that seismity is now centered on Arenas Crater, and even though these images (AZUM_HHE_CM90 at these helicorders) are without context, it doesn't take a PhD in seismology to see that what Ruiz was doing at midnight last night:

-- is not what it's doing today at noon, on the same instrument (it does help to have enough familiarity with helicorders to see that these changes look volcanic, not induced by weather, water, or other noise):

BTW, that long big-squiggly line last night was probably just an ash emission, which Ruiz has been having occasionally these days.

 

[bjdeming]

Those are scary-looking, but remember: the people who can actually read them are, for now anyway, keeping Ruiz at ORANGE, the second-highest level.

 

[bjdeming]

If you are there, or know someone there, the SGC tweeted this yesterday after an ash emission; it's good advice now, too:



Per Twitter translation: "We recommend that the communities surrounding the volcano follow the instructions of the National Unit for Disaster Risk Management (UNGRD) and the local authorities, as well as keeping informed through the official channels of the Colombian Geological Service."

Another meaning of "follow" today could be "with your feet moving and with bug-out bag in hand" along with "read" and "subscribe."

 

[bjdeming]

It has been active lately but SGC is keeping it at Yellow and advising everyone to stay alert.

Right now there is occasional lightning on the cam -- the general weather report online mentions "cloudy," so it may be volcanic lightning (or perhaps weather).


For scale, that light on the lower right is an army base!

 

[bjdeming]

I'm real glad the worst didn't during that round of increased activity.

It does continue with low-level eruptions, including this one recently:



Twitter translation: "This video was recorded by a team from the Colombian Geological Service that was doing field work on April 13 from the Bruma monitoring station, located at 4860 m above sea level. n. m., and shows an emission of ash associated with seismic activity and that was recorded at 10:07 am at the Nevado del Ruiz volcano

For more than ten years, this volcano has been the most active in Colombia and is in an eruptive process, characterized by minor eruptions (ash emissions with column heights less than 3 km), which do not considerably affect the population. .However, and for this reason, it is important not to normalize the behavior of this volcano that is in a state of Yellow alert

, especially when the variations of the monitored parameters are minor in the short term.The Yellow alert status indicates that the volcano presents less instability behavior and, consequently, less probability of making a considerable eruption.

This is why we must keep in mind that its activity levels are far above those of any other volcano in Colombia in this state, and that at any time its activity could increase rapidly and move to a state of Orange alert

( volcano with important changes in the monitored parameters) or even to Roja

(volcano erupting).From the SGC we reiterate the danger posed by being near the volcano's crater, and we call for tourists and other interested citizens to carefully follow the evolution of the volcano through the bulletins that we publish every Tuesday

, as well as others. information shared on our official channels, and the instructions of local and departmental authorities and the National Unit for Disaster Risk Management (UNGRD)."