Nevado del Ruiz: May 17 (1624 UTC)

  • Status: Orange, but —

    They don’t usually make such tweets daily. See May 1st 5:04 p.m. update below.

  • Interactive official hazard map (autotranslated), via Relief Web; En español
  • Links to webcams, public data, and other information.
  • Update archive.

Update, May 17, 9:24 a.m., Pacific: Well, the mountain remains socked in, and things appear rather quiet at the moment, though there was an ash advisory for a bit; none is in effect at present.

Per this video uploaded about an hour ago by Tolima Civil Defense, Ruiz is once sgain nevado:

Nevertheless, something to the southwest, not at a very great depth, (though not exactly superficial, either), is still breaking rocks down there, per the SGC’s report today via Google Translate (emphasis from either SGC or me:

From 09:00 a.m. yesterday (May 16) until the time of publication of this bulletin, the seismic activity associated with rock fracturing inside the volcanic edifice presented a decrease in the number of earthquakes and in the seismic energy released compared to the previous day (15 of May). This type of seismicity continues, mainly characterized by the occurrence of small earthquakes, located in the Arenas crater, which are associated with the activity of the lava dome (bulge or mound) located at the bottom of the crater. Additionally, seismicity continues to be located in the southwestern sector of the volcanic edifice, at a distance between 3 and 4 km from the Arenas crater, with depths that ranged between 3 and 4 km. The maximum magnitude recorded was 1.0, corresponding to the earthquake registered on May 16 at 02:14 a.m., located 4 km southwest of the Arenas crater and at a depth of approximately 4 km.

The seismicity related to the movement of fluids inside the volcanic conduits showed similar levels in the number of registered events and a decrease in the seismic energy released compared to the previous day (May 15). Some of the seismic signals were associated with pulsatile ash emissions confirmed through the web cameras used for volcanic monitoring.

In relation to surface activity, the maximum height of the gas column was 1500 m, measured from the top of the volcano. During yesterday, the dispersion of the column prevailed towards the northwest. In recent days, the weather conditions have not been favorable, which has limited the visualization of the bottom of the crater and the monitoring of thermal anomalies from satellite monitoring platforms. However, this does not mean that they are not present. On the other hand, variations continue in the degassing of sulfur dioxide and the release of water vapor from the crater into the atmosphere.

All these indicators ratify what the SGC has reiterated: the activity of the Nevado del Ruiz volcano continues to be highly unstable. It is possible that the levels of seismic activity, as well as the levels of degassing or ash output, decrease or be oscillating, in the sense of increasing on some days and decreasing on others. However, this does not imply that the volcano has returned to its normal levels of activity, so it is recommended not to get used to these oscillating changes in activity and think that it is a normal activity of the volcano.

Therefore, we reiterate that the activity of the Nevado del Ruiz volcano continues at ORANGE LEVEL, which indicates that there is a probability that in days or weeks it will erupt more than it has in the last 10 years. To change the level and return to the Yellow level, a prudential time is required where trends and patterns can be observed that allow us to infer the possible decrease in activity, aspects that the current activity of the volcano still does not show. For this reason, we warn that the level of activity of the Nevado del Ruiz volcano will remain at ORANGE LEVEL for several weeks. During this time, in the event of an acceleration of processes suggesting an imminent eruption or the eruption itself occurring, the activity level will be changed to Red.

We recommend that the community remain calm, follow all the instructions of the National Unit for Disaster Risk Management (UNGRD) and local authorities, and be attentive to the information provided by the Colombian Geological Service on the evolution of the state of the volcano.

The level of activity of the volcano remains at ORANGE LEVEL of activity or (II): PROBABLE ERUPTION IN TERMS OF DAYS OR WEEKS.

The COLOMBIAN GEOLOGICAL SERVICE will continue to be attentive to the evolution of the volcanic phenomenon and will inform opportunely about the changes that may occur.

For more information visit the following link:

[Layperson speculation]My guess is that the recent emissions from May 11th on have relieved whatever pressure had built up from rising magma — remember: the dome up there reportedly doesn’t cover the whole vent. Now, there might be more room for deeper magma to move up from the southwest. Recall this:

Why is the magma coming from the southwest? If this model is correct, because that’s where the chamber is. Why it’s bypassing nearby Isabel and heading Ruiz, I don’t know. (Image: Lundgren et al., Figure 5 (top), Figure 6, partial (bottom), CC BY 4.0)

As far as I understand it (not far at all), magma rises from that chamber in batches that pause and spread out into sills at depths where they could cool and harden if something didn’t keep the magma moving.

If it mostly ends up in sills, it will eventually stop without an eruption; if the stuff keeps coming up — and particularly if the entire Arenas vent plugs up or if a really big magma batch comes up too fast for the existing conduit to handle — then BOOM.

As mentioned in an earlier post, I hope it doesn’t erupt; everyone will have worked through lingering psychological effects from November 1985 and will now be more able to cope with whatever Ruiz eventually does.

But I also don’t want this to last so long that it becomes a major economic disaster for this touristic region.(/Layperson speculation]

Featured image: Ric Photography/Shutterstock

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