Cotopaxi

Cotopaxi is made of layers from many eruptions.

It has erupted many times over hundreds of years.

Cotopaxi is a stratovolcano: a cone built up from layers left by many eruptions. Its sides slope up to a crater at the very top.

The IG-EPN lists five big eruptive periods since the 1500s: 1532 to 1534, 1742 to 1744, 1766 to 1768, 1853 to 1854 and 1877 to 1880.

A stratovolcano is a cone built from layers of lava and volcanic debris. A USGS study counts 59 explosive eruptions from Cotopaxi's summit crater between 1532 and 1942; lava flows came with 27 of them, and lahars formed in 27 cases.

The IG-EPN names five large eruptive periods since the 1500s (1532-1534, 1742-1744, 1766-1768, 1853-1854 and 1877-1880) and says the volcano has a high rate of recurring eruptions, so a new eruption in the future is very likely, though its exact timing and size are hard to predict.

Cotopaxi is close to the Equator, but it is high enough to have ice on top.

The ice flows down its sides as glaciers.

Ecuador sits on the Equator, yet some of its mountains reach high enough to hold glaciers. The US Geological Survey (USGS) describes an ice cap on Cotopaxi with 23 outlet glaciers flowing from it.

The USGS also noticed a narrow strip with no ice along the volcano's western slope, running up to the crater. It says this is probably caused by heat from inside the volcano.

In the USGS glacier atlas chapter on Ecuador (Jordan and Hastenrath, 1998), Cotopaxi has an ice cap with 23 outlet glaciers covering 19.09 km², mapped from field surveys in 1977 and 1980-1981 and later image work. The authors call it the best example of a glacier-covered active volcano in the tropics.

They note a narrow ice-free strip along the western slope up to the crater, probably caused by geothermal processes, and a dark ring of ash below the glaciers where no plants grow. They also report a significant reduction in glacier area in Ecuador since the 1800s that apparently still continues.

Grassland called páramo grows around Cotopaxi.

Andean condors, deer and rabbits can be seen there.

Cotopaxi National Park was created on July 26, 1979. A visitor guide for a 2010 conference says the park covers 33,393 hectares, from 3,400 meters up to the summit.

At Limpiopungo Lagoon, at 3,850 meters, visitors can see birds such as gulls and ducks. The guide also lists deer, rabbits, llamas and the Andean condor.

The IG-EPN describes Cotopaxi as surrounded by páramo, a high Andean grassland. According to the 2010 visitor guide (prepared for an international conference in Quito), Cotopaxi National Park was created on 26 July 1979, covers 33,393 ha in parts of three provinces and ranges from 3,400 m to the 5,897 m summit.

Limpiopungo Lagoon, at 3,850 m and about 200 ha, has páramo gulls, ducks and birds called quilicos; the guide also lists deer, rabbits, llamas and the Andean condor. Fields of gray lava rock on the way to the volcano are reminders of past eruptions.

Scientists watch Cotopaxi closely.

Before a big eruption, they expect to see warning signs.

The IG-EPN says Cotopaxi is one of the most closely watched volcanoes in Ecuador. In 1976 it got the first permanent earthquake-recording station in South America set up just to watch a volcano.

In 2015 the ground began to change shape, earthquakes increased and more gas came out, and an eruption began on August 14. It lasted until late November and sent ash mostly to the west. Another small eruption of gas and ash ran from October 2022 to July 2023.

The IG-EPN monitors Cotopaxi's earthquakes, ground deformation, hot springs and gas release. The first permanent seismic station in South America dedicated to watching a volcano was installed here in 1976.

From early 2015 deformation, earthquakes and gas output rose, leading to an eruption from 14 August to late November; it was small (VEI 1), but ash falling mostly to the west hurt farming and tourism in Cotopaxi province. NASA reported it as the first significant eruption in more than 70 years. A new period of small gas and ash emissions ran from mid-October 2022 to July 2023: longer than 2015, with only half the ash. The IG-EPN says a larger eruption would be preceded by clear warning signs, allowing alerts days or weeks ahead.

It is cold and high up on Cotopaxi. Wear warm layers, a hat and gloves.

If your head hurts up high, tell a grown-up and go lower.

The 2010 visitor guide says the average daytime temperature is about 7°C (45°F), and it can drop below freezing. It suggests several layers of clothing, a warm jacket, a windbreaker, a hat, gloves and hiking shoes.

The whole park lies above 3,400 meters. The US Centers for Disease Control and Prevention (CDC) says children can get altitude sickness just as adults can, a headache is the main sign, and going down at least 300 meters helps.

Daytime temperatures average about 7°C (45°F); with the seasons and at night they can range from below freezing to 20°C, so the guide recommends layers, a warm jacket, a windbreaker, hat, gloves and hiking shoes. The IG-EPN recommends the official volcanic hazard maps for how each eruption scenario could affect the area.

The CDC's Yellow Book says any unacclimatized traveler sleeping at 2,450 m or higher is at risk of altitude illness, children are as susceptible as adults, headache is the cardinal symptom of acute mountain sickness, and a descent of 300 m or more brings rapid improvement.