Costa Rica’s Rincón de la Vieja shows signs of increased activity


Costa Rica's Rincon de la Vieja volcano is showing signs of increased activity since September 17, 2014. Phreatic explosions have regularly occurred from the main crater which contains an acid lake. An aerial survey on Friday showed no fresh deposits, which suggests that the eruptions were rather small and did not eject material beyond the lake. Although none was observed directly, at least 6 explosions could be identified by seismic signals.

Based on the observations by park rangers the volcano is currently experiencing strong bubbling at the lake and floating sulfur rafts on the surface. The water temperature has increased significantly by 15 degrees Celsius, compared to measurements made in 2013. 

Hot, acid mud flows (lahars) if larger explosions cause the lake to drain or eject larger quantities of water would be the main hazard from the volcano at present. Such lahars could affect all sides of the volcano, but the areas to the NE around the Azul and Pénjamo river beds would be most at risk. They have already been affected by lahars during previous eruptions.

At the moment, it is impossible to know whether the current activity is a precursor of a new magmatic eruption or will remain a more or less intense phase of phreatic explosions, caused by readjustments in the shallow hydrothermal system rather than fresh rising magma. (VolcanoDiscovery)

The volcano has had similar crisis as recently as 1998, 2011, and 2012. None of them was followed by the eruption of magma, and only phreatic (steam-driven) explosions occurred. The last magmatic eruption was in 1995. 

Rincon de la Vieja last appeared in the GVP's weekly volcanic report during the week of February 27 – March 5, 2013: 

OVSICORI-UNA received reports at 05:30 on February 26 of pulsing white plumes rising from Rincon de la Vieja's active crater about every four minutes. The seismic records showed no signals associated with a phreatic eruption or sudden gas output. Cloud cover prevented views of the active crater during an overflight later that day, however clear views of the N and S flanks and areas SW showed no changes. 

Geologic summary

Rincón de la Vieja is the largest volcano in NW Costa Rica, is a remote volcanic complex in the Guanacaste Range. The volcano consists of an elongated, arcuate NW-SE-trending ridge that was constructed within the 15-km-wide early Pleistocene Guachipelín caldera, whose rim is exposed on the south side. Rincón de la Vieja, sometimes known as the "Colossus of Guanacaste," has an estimated volume of 130 cu km and contains at least 9 major eruptive centers.

Activity has migrated to the SE, where the youngest-looking craters are located. The twin cone of 1916-m-high Santa María volcano, the highest peak of the Rincón complex, is located at the eastern end of a smaller, 5-km-wide caldera and has a 500-m-wide crater. A plinian eruption producing the 0.25 cu km Río Blanca tephra about 3500 years ago was the last major magmatic eruption from the volcano.

All subsequent eruptions, including numerous historical eruptions possibly dating back to the 16th century, have been from the prominent crater containing a 500-m-wide acid lake (known as the Active Crater) located ENE of Von Seebach crater.

Featured image credit: GVP

If you value what we do here, create your ad-free account and support our journalism.


Related articles

Your support makes a difference

Dear valued reader,

We hope that our website has been a valuable resource for you.

The reality is that it takes a lot of time, effort, and resources to maintain and grow this website. We rely on the support of readers like you to keep providing high-quality content.

If you have found our website to be helpful, please consider making a contribution to help us continue to bring you the information you need. Your support means the world to us and helps us to keep doing what we love.

Support us by choosing your support level – Silver, Gold or Platinum. Other support options include Patreon pledges and sending us a one-off payment using PayPal.

Thank you for your consideration. Your support is greatly appreciated.

Teo Blašković

$5 /month

  • Ad-free account
  • Clean user interface and fast browsing
  • Direct communication with us via chat and email
  • Suggest new features, content and applications
  • Early access to new apps and features

$50 /year

$10 /month

  • Ad-free account
  • Clean user interface and fast browsing
  • Direct communication with us via chat and email
  • Suggest new features, content and applications
  • Early access to new apps and features

$100 /year

$25 /month

  • Ad-free account
  • Clean user interface and fast browsing
  • Direct communication with us via chat and email
  • Suggest new features, content and applications
  • Early access to new apps and features

$200 /year

You can also support us on Patreon

support us on patreon

or by sending us a one-off payment using PayPal:

Commenting rules and guidelines

We value the thoughts and opinions of our readers and welcome healthy discussions on our website. In order to maintain a respectful and positive community, we ask that all commenters follow these rules:

  • Treat others with kindness and respect.
  • Stay on topic and contribute to the conversation in a meaningful way.
  • Do not use abusive or hateful language.
  • Do not spam or promote unrelated products or services.
  • Do not post any personal information or content that is illegal, obscene, or otherwise inappropriate.

We reserve the right to remove any comments that violate these rules. By commenting on our website, you agree to abide by these guidelines. Thank you for helping to create a positive and welcoming environment for all.

Leave a reply

Your email address will not be published. Required fields are marked *