Caribbean Plate Volcanoes: The Central American Arc

The Caribbean tectonic plate gets little respect. This is probably why it lashes out so violently at times in earthquakes and volcanic explosions.

First, most of this relatively small chunk of Earth’s lithosphere is underwater, so hardly any of us even know it’s there.

Then North America jostles it from the north, messing up its boundaries, while South America does the same thing to the south. East and west, seafloors on other plates dive underneath the Caribbean plate’s edge in subduction zones and then melt upward through it to form explosive volcanic arcs.

These are the Lesser Antilles island arc in the east and the land-bound Central American Volcanic Arc to the west.

This post is about those Central American volcanoes–well, not all of them. There are hundreds of stratovolcanoes, lava domes, and cinder cones in this group.

Let’s break it down by country.

Guatemalan volcanoes

Here are a just a few of the 300+ vents in this small nation.

Monitoring: INSIVUMEH. (Spanish)

Risk: High, obviously. In fact, only Indonesia has more people living near active volcanoes. (Ewert and Harpel) According to one source:

The highest risk is located around the vents of Almolonga and Santa Maria, due to the very large population living within 10 km of the volcanoes and also the high VEI 6 figure for Santa Maria as designated by the Global Volcanism Program. The areas to the south and east of Fuego are also designated high risk due to the numerous hazards that combine and overlap within these areas, from hazards generated by Atitlan and Acatenango.

Biggest known eruption: That 1902 VEI 6 event at Santa Maria, in which thousands of people died, was the second largest eruption of the 20th century (the largest one, in 1912, happened in Alaska).

And then there was the VEI 7 caldera eruption at Atitlán during the last ice age some 85,000 years ago. Today a lake fills the caldera left by this “Los Chocoyos eruption,” and “normal”-sized eruptions at one of the three stratovolcanoes on the calderas rim are the norm.

El Salvador

This is the country where cameras caught the start of an eruption at Chapparastique Volcano, the most active of some 20 or so El Salvadoran volcanoes. You might have seen the video:

Monitoring: SNET. (Spanish)

Risk: High.

Biggest known eruption: A few high-end VEI 6 eruptions and one VEI 7 are listed.

Also, a VEI 6 caldera eruption at Ilopango, which sits right next to the country’s capital city, happened in the fifth or sixth century AD.

Besides devastating the Maya politically and economically, as well as socially, this “Tierra Blanca Joven eruption” may have caused climate effects and hardship elsewhere in the world, and possibly even contributed to the Justinian Plague! (Oppenheimer)

Nicaragua

There are at least 19 volcanoes in this country, and some of them are popular tourist destinations.

Monitoring: Hard to say. The link given at WOVO doesn’t work.

Risk: Per this abstract, there are a variety of risks.

They don’t mention gas, probably because that is a common (and very dangerous) volcanic hazard everywhere:

Biggest eruption: Both Apoyeque and Masaya have had VEI 6 eruptions, though not any time recently; Masaya’s eruptions are usually less intense.

Costa Rica

This country’s beautiful string of volcanoes draws a lot of tourists.

It is quite a beautiful country.

Monitoring: OVSICORI-UNA. (Spanish)

Risk: High.

Biggest eruption: An unexpected VEI 3 eruption at Arenal in 1968 killed 87 people, per Wikipedia. Also, a few Costa Rica volcanoes, including the Barva complex, Miravalles, and Poás have VEI 6 or 7 eruptions listed in the distant past.

Panamá

Wait, Panamá has volcanoes? Yes, at least three of them.

Monitoring: The National Civil Protection System, apparently. They responded to what turned out to be false concerns in 2015 that Barú was going to erupt.

Risk: Barú is the youngest and most recently active volcano, so most attention focuses on it.

Biggest eruption: El Valle had a VEI 4 ignimbrite eruption about 56,000 years ago, though it has been quiet ever since.

By now, you have probably forgotten the poor Caribbean plate–no respect–but it’s still there, underneath all these Central American lands, interacting with various microplates that lay between it and the huge Pacific tectonic plate.

Let’s close by standing atop Barú volcano – the only place in the world where, thanks to the narrowness of the Panama isthmus, you can see the Atlantic (on our right) and the Pacific (left) oceans at the same time.


Featured image: Central America volcanic front. CrazyKnight. CC BY-SA 3.0.



Sources:

Bachmann, R. 2001. The Caribbean plate and the question of its formation. Institute of Geology, University of Mining and Technology Freiberg Department of Tectonophysics http://www.redciencia.cu/geobiblio/paper/2001_Raik%20Bachmann_THE%20QUESTION%20OF%20ITS%20FORMATION.pdf.

Ewert, J. W., and Harpel, C. J. 2004. In harm’s way: Population and volcanic risk. Geotimes. http://www.geotimes.org/apr04/feature_VPI.html Last accessed March 18, 2018.

Giunta, G. and Orioli, S. 2011. The Caribbean Plate Evolution: Trying to Resolve a Very Complicated Tectonic Puzzle, New Frontiers in Tectonic Research – General Problems, Sedimentary Basins and Island Arcs, ed, Sharkov, E. InTech, DOI: 10.5772/18723. Available from: https://www.intechopen.com/books/new-frontiers-in-tectonic-research-general-problems-sedimentary-basins-and-island-arcs/the-caribbean-plate-evolution-trying-to-resolve-a-very-complicated-tectonic-puzzle

Oppenheimer, C. 2011. Eruptions That Shook The World. Cambridge: Cambridge University Press. Retrieved from
https://play.google.com/store/books/details?id=qW1UNwhuhnUC

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.