There are so many volcanoes right now that have the size and history to produce a massive eruption but only one volcano has me worried for the imminent future and you’ve heard it’s name before, Chiles-Cerro Negro. As of late Chile-Cerro Negro has been having a massive swarm with accelerating deformation which has caught some attention from our community and as the volcanoes representative it is my duty to give you an update on the volcano’s current situation. I have already wrote too many articles of subpar quality concerning this volcano and I don’t really want you to go back and read those. But I also don’t want to retrace old ground and this article will be all you need to understand this volcano’s current situation, and what is so concerning about this volcano.
Located on the border of Columbia and Ecuador, this system consists of the 2 stratovolcanoes and 1 caldera at the minimum and it has been dormant for over 12,000 years. Something changed in 2013 when an intrusion began, starting a massive swarm and for almost 10 years this volcano has been under constant changes which leads me to believe that this volcano has some scary potential. It may seem a bit disingenuous, after all this volcano at a glance seems to be your typical stratovolcano couplet but this couldn’t be further from the truth.
There are 2 calderas and several other volcanic features near the volcano that are all uplifting or under seismic stress. That is not indicative of modest potential. 20 km wide area was under uplift surrounded by a ring of subsidence, something that occurs at caldera volcanoes but not really at stratovolcanoes. On top of that, regional faults have been under stress for over 8 years. This never sounded like your typical volcanic unrest but now? Now it’s clear as day that something is very wrong with our black hill.
The red flags began in 2018 when the second swarm began. Despite being reasonably large, there was no official confirmed cause but it had been postulated that this was the result of magma chamber pressurizing. 200,000+ quakes don’t just happen for no reason and I was confused to see an underwhelming response by the geological agencies. More than 4 volcanoes under unrest at once? Large inflation? Stressing regional faults? Dormant for years? This all sounds pretty interesting!
But after 2020, the activity at Chiles-Cerro Negro fell of a cliff, deformation stabilized, quakes became scarce. It got to a point that I started to wonder if the volcano was about to back to dormancy but I noticed while Chiles-Cerro Negro activity was going down, Cumbal’s was going up. Now I don’t believe Cumbal is part of the same magmatic system but these two volcanoes share the same tectonic system and the hydrothermal activity at Cumbal is influenced by the tectonic stress at Chiles-Cerro Negro. A seismic uptick at Cumbal gave me suspicion that everything hadn’t returned to normal and I was right.
Starting in April, LP earthquakes started to take place at our Black hill with a SHARP rise in deformation. Let me just say that if the instruments are working properly then this is the most incredible deformation I have ever seen on an Inclinometer. Since the swarm began there has been a shift of over a million microradians at two instruments and uplift has rose to over 10 cm/year at one station with faster uplift likely further south.
This isn’t it though, despite the scary numbers the real fear-stoker is where the LP earthquakes are taking place; in April these were taking place 30 km below the surface but now they’re taking place 1-2 km below the surface with more LP earthquakes than any other of the past swarms. The current unrest is most likely being driven by a large volume of buoyant magma, and to make matters worse, the hydrothermal system is being disrupted by this magma and there is still no surface degassing of this shallow magma which means the system is plugged.
First swarm- Magma intrusion
Second swarm- chamber pressurization
Third swarm-ascending magma
I still don’t think we’ve reached the point of no return but only a fool wouldn’t watch this volcano like a hawk. I can’t speak to how exactly big this volcano is, or if it’s going to erupt but if it does erupt, it’s going to be big. I have never seen such a coalition of so many insane numbers in one volcano and nothing points to this volcano being small or modest in size
Is this the VEI 6+ caldera-forming volcano we’ve been anticipating? We’ll see.