·

Strongest seismic unrest under the Cayambe volcano since 1995, Ecuador

strongest-seismic-unrest-under-cayambe-volcano-since-1995-ecuador

Ecuador's Instituto Geofisico (IG) reports a sharp increase in seismicity under the Cayambe volcano this month. It became more evident in the middle of June, but at the moment, the seismicity tends to decrease. The last known eruption of this volcano  in 1786. Statistically, this volcano erupts every ~200 years.

Although the seismicity under Cayambe is decreasing at the moment, IG said it should be noted that this is the strongest seismic anomaly recorded since 1995. 

The seismic events are related to fracturing of rocks and are located at the NE end of the volcano. At this time, GPS data from networks and inclinometers installed on the volcano show no evidence of deformation in the volcano.

Cayambe is a massive compound andesitic-dacitic stratovolcano, located on the isolated western edge of the Cordillera Real, east of the Inter-Andean Valle. This is 60 km (37 miles) NE of Quito and 15 km (9 miles) E of the town of Cayambe, population 20 000.

Cayambe's summit is formed by a complex of domes, including the western summit stands with a maximum height of 5 790 m (18 991 feet). It has an ice cap that starts around 4 800 m (15 750 feet), with an area of approximately 22 km2 (8.5 mi2).

In the past 4000 years, at least 21 eruptive events were identified of which the most recent was between 1785-1786 (Samaniego et al. 1998). Statistically (based on geological studies), the Cayambe volcano has a recurrence period of eruptions about 200 years, IG said.

The image below shows the monthly seismicity from 1995 to June 19, 2016.

Monthly number of events recorded in the Cayambe volcano since 1995 – June 19, 2016. VT = volcano-tectonic, LP = long period, TREM = episodes of tremor and HB = hybrid. Credit: IG

Total number and type of daily earthquakes at Cayambe volcano from January 1 – June 19, 2016. Credit: IG

VT events recorded in this month show a concentration northeast of the volcano:

Credit: IG

The location of these earthquakes to the northeast boundary of the volcanic edifice can classify this as a swarm of volcano-tectonic earthquakes. It should also be noted that, so far, there is no evidence of deformation in the volcano that could indicate the presence of a magmatic intrusion.

Cayambe volcano from Quito, Ecuador. Author: Patomena (via Wikimedia Commons)

The Geophysical Institute continues to monitor the volcano.

Geological summary

The massive compound andesitic-dacitic Cayambe stratovolcano is located on the isolated western edge of the Cordillera Real, east of the Inter-Andean Valley. The volcano, whose southern flank lies astride the equator, is capped by extensive glaciers, which descend to 4200 m on the eastern Amazonian side. The modern Nevado Cayambe, constructed to the east of older Pleistocene volcanic complexes, contains two summit lava domes located about 1.5 km apart, the western of which is the highest. Several other lava domes on the upper flanks have been the source of pyroclastic flows that reached the lower flanks.

A prominent Holocene pyroclastic cone on the lower E flank, La Virgen, fed thick andesitic lava flows that traveled about 10 km E. Nevado Cayambe was recently discovered to have produced frequent explosive eruptions beginning about 4000 years ago, and to have had a single historical eruption during 1785-86. (GVP)

Featured image: Cayambe volcano from Quito, Ecuador. Author: Patomena (via Wikimedia Commons). Seismic data: IG. Edit: TW

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

Share:

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.

Sincerely,
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 *