13 comments on “The Michoacán – Guanajuato Volcanic Field, Mexico

  1. For the Icelandically inclined, a visualization of the recent swarm in Tjörnes Fracture Zone

    Data from NOAA (topography) and IMO (earthquakes)
    Color : Blue for oldest Red for Youngest


    • I’ve been hoping you’d come up with this, thanks, dfm! Amazing how it rises in 3-4 distinct batches side by side and one after another. I wonder if this is now one broad dike or three separate ones.


      • Hi Granyia

        Iceland quakes are always a pleasure to look at because there are this sort of “upwelling”.
        I do not know enough the geology of this part of Iceland to emit suggestions. It is true that there are very distinct events with separate “sheets” . They are distinct in time so it would seem that the magma is trying to find a way up.


  2. Thank you, agimarc! I still don’t get why there are clusters of monogenetic cones rather than central volcanoes. I mean, the magma source below does not disappear after an eruption. Yet, the next batch creates a new path and erupts a few kilometers further away, even within a relatively short time. In other places of the world magmas would go a long distance sub-surface in order to reach a pre-existing outlet – like Katmai>Novarupta.

    Is this perhaps because this area is highly cracked and broken by the very complex tectonic movements? So each (even small) batch of magma would find an almost direct way up and out without having the time to create a permanent plumbing system? (But then, the Katmai region has complex tectonics as well.)


    • Howdy Granyia –

      I think it has a lot to do with how cracked and broken the various blocks are and how they are jostling against one another. Large stratovolcanoes appear at intersections of fault lines – Colima and Popocatepetl for example. Looked like an initial slug of magma at El Jorrulo rose and then stalled until remobilized by the slug of magma that finally made it to the surface. I still don’t understand completely how or why monogenetic fields work, which is one of the reasons I keep on looking at them, There are similarities with NM, Arizona, Utah, Mexico, and Nevada though I have not figured out a way to describe those similarities yet. Cheers –


  3. I have not studied volcanology. I live on the side of Estribo volcano in Patzcuaro, Michoacan, MX. I am just looking for a good history of first and last eruptions. Is it considered extinct? As I look out my window I see what looks to be another volcano across Lake Patzcuaro. I have spent hours and days researching this but can find nothing definitive. Couild you help a lay person?


    • Howdy Kitty. Thanks for reading our blog. A quick look into El Estribo looks like it was active 128 – 100,000 years ago and again some 28,000 years ago. The first period build the underlying shield. The most recent built the cinder cone capping it. Haven’t looked far enough to figure out what is on the other side of the lake. But thank you for the suggestion for a future post. It will be a while as I am in the middle of our summertime routine and will be busy for the next couple months. Will let you know when the new post is up. Note that neither of us are experts. Merely hobbyists who think these are interesting things to look into and try to figure out how they work. Cheers –


  4. Pingback: El Estribo Volcanic Complex, Mexico |

  5. Pingback: Guest Video: Why Do Volcanoes Erupt? – Flight To Wonder

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