BJ Deming

Nevado del Ruiz: May 27 (1755 UTC)

  • Status: Orange, but —

    https://platform.twitter.com/widgets.js

    The take-away here: Ruiz might wind up steadily, if that’s on its agenda, or it might just give them a few minutes’ notice before the “big one.”

  • Interactive official hazard map (autotranslated), via Relief Web; En español
  • USAID April 4th map (autotranslated) posted on May 18 at Relief Web.
  • Links to webcams, public data, and other information.
  • Update archive.

Update, May 27, 10:55 a.m., Pacific: There isn’t much change yet, though Ruiz is not dozing off to sleep, either.

VAAC ash advisories ended yesterday; the helicorders still appear rather lively.

Visibility is an issue, given weather clouds, but there doesn’t seem to be quite as much of a plume this morning:

https://youtu.be/HQynZkW12nI&rel=0

As usual, Jhon/VIDJCB reads the SGC daily bulletin.

Here is the gist, via Google Translate (emphasis by SGC or me:

From 09:00 a.m. from yesterday (May 26) until the time of publication of this bulletin, the seismicity related to the movement of fluids inside the volcanic conduits increased in the number of registered earthquakes and maintained seismic energy levels, compared to May 25.
This type of seismicity was mainly characterized by the occurrence of small earthquakes,located in the Arenas crater, which are associated with the activity of the dome (protrusion or mound) of lava located at the bottom of the crater. Some of the seismic signals were associated with pulsatile ash emissions confirmed through the web cameras used to volcanic monitoring.

On the other hand, the seismic activity associated with rock fracturing inside the volcanic edifice continued that has been recorded since May 24 in the northeastern sector of the volcano, a maximum distance of 4 km from the Arenas crater and at depths between 4 and 6 km. This seismicity presented a decrease in the number of earthquakes and similar seismic energy compared to May 25. Seismicity was also occasionally recorded in the Arenas crater. The maximum registered magnitude was 1.4 ML, corresponding to the earthquake at 02:03 p.m., located 4 km, to the northeast of the Arenas crater, and at an approximate depth of 5 km from the top of the volcano.

Regarding surface activity, the maximum height of the gas and/or ash column was 1000 m, measured from the top of the volcano. The preferential direction of dispersal was maintained mainly to the northwest and west of the volcano. Variations continue in the degassing of sulfur dioxide and the release of water vapor from the crater into the atmosphere.

We reiterate, once again, that the activity of the Nevado del Ruiz volcano continues to be very unstable. It is possible that the levels of seismic activity, as well as the levels of degassing or output of ash decrease or are oscillatory, 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 that it is recommended not to get used to these oscillating changes of activity and think that it is a normal activity of the volcano.

Therefore, the activity of the Nevado del Ruiz volcano continues at the 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 the
activity, aspects that the current activity of the volcano still does not show. For this reason, we note 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 the processes that suggest an imminent eruption or the eruption itself, the level of activity will change to Red.

We recommend that the community remain calm, follow all the instructions of the Unit National 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 COLOMBIAN GEOLOGICAL SERVICE will continue to monitor the evolution of the volcanic phenomenon and will inform in a timely manner about the changes that may occur.

For more information visit the following link:
https://www2.sgc.gov.co/Noticias/boletinesDocumentos/Forms/AllItems.aspx

Per an article (autotranslated) at Relief Web, as of April 2023:

At least 6,100 people in rural areas of 6 municipalities already have an evacuation order due to being at high risk, given the proximity to the crater and having a great impact due to pyroclastic density currents; while 130,000 people in rural areas of 29 municipalities and 4 departments are at high and medium risk due to exposure to different types of hazards, including high-density ash, of which 64,700 would be at high risk.

Featured image: Ric Photography/Shutterstock

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