Nicaraguan Volcanoes

I visited Nicaragua for a few days in 1973 to study the active volcanoes. This was my first experience in a Spanish-speaking country. Nicaragua was in shambles because, late in December 1972, a powerful earthquake destroyed the capital city of Managua. We spent most of our time based out of the city of León, returning to Managua just before our departure. These are the volcanoes we visited:
Cerro Negro
San Cristobal
Earthquake Damage


Momotombo is one of the higher volcanoes in Nicaragua. Most of our class climbed it but a few others and I went out with some geophysicists, working on a United Nations contract, prospecting for hot water for geothermal power. They were eventually successful and a geothermal power station now generates from near this photo.

Cerro Negro

Cerro Negro was the very first active volcano that I ever visited (November 1973). Although it wasn't erupting at the time, it had erupted a few years earlier and has erupted several times since. Unfortunately, I never took a picture of the mountain but I got a few nice shots during the climb. This photo shows the 1968 lava flow and ash fall into the jungle. The two green areas within the flow are called kipukas. These are areas that the flows never covered. The two green areas were missed by the lava flows. Hawaiians call these areas kipukas: a name now generally used wherever these occur.

Apparently, this anteater thought that the volcano was a large ant hill. We found him nearly dead of thirst at the Cerro Negro summit. We poured some water into a plastic bag and he revived very quickly. We couldn't coax him down the mountain so we just left him there. The next day the group that climbed the mountain found him nearly dead of thirst...

This image was taken from the west side of the crater rim looking across the crater. The two faint, fuzzy white dots on the far rim at the center are two of my companions. In the lower right is the trail that leads down to the active fumaroles.

We hiked into the crater to sample the hot gases emanating from the fumarole. The superheated water contains many dissolved minerals which precipitate out when the steam rapidly cools upon contact with the atmosphere. The yellow mineral here is ralstonite, an aluminum chlorhydrate; the white is gypsum (calcium sulfate). Our professor, Dr. Richard E. Stoiber, sampled the gases to look at the relative amounts of sulfur dioxide and hydrochloric acid. Changes in the ratio of these constituents are viewed as precursors to an eruption. This particular fumarole was sampled every month for that reason.

The guy in the photo is my classmate, Tim O'Conner.


San Cristobal

San Cristobal is the highest mountain in Nicaragua. It had been inactive since Spanish colonization. A few years prior to our visit, however, the mountain began releasing a tremendous volume of gas, killing off the forest that engulfed the crater and the summit. This image shows the gassed forest near the summit of the volcano.

An older, extinct cone lies just to the west of San Cristobal. 

By the time we reached the summit, it was completely engulfed in clouds. Strong winds, gusting up to 90 MPH, according to our anemometer, pelted us with cinders picked up off of the ground. Almost everyone got discouraged and started back down the mountain. I lingered a bit at the summit. Suddenly, the wind blew the clouds away. Below me was a wide seething crater and out in front was a view down the volcanic chain to the southeast. Momotombo is the peak on the horizon just to the right of center. Telica is in the middle foreground.

A few months before we arrived, the level of fumarolic emissions dropped dramatically. Our class climbed the mountain. Four of us entered the crater, which had not been visited since the gas emissions fell off. This is a photomosaic I took from the crater rim as we hiked into San Cristobal. The active fumarolic crater is on the left. It appeared to be made mostly of gypsum, a hydrous calcium sulfate mineral.

This mosaic shows a large crater composed of fumarolic minerals that had formed during the gas emission phase. 
Note that there is still a lot of gas coming out! Overall, this was a pretty poisonous place.

The floor of San Cristobal crater must have been what Dante envisioned. Hell couldn't be too much worse than this place.

Graduate student Mike Carr (now a longtime professor at Rutgers) had just burned his hand on the hot rock that had a large fumarole spewing gas from underneath. We sampled the gases from this one. The yellow mineral shown here is sulfur.

This was the most poisonous place I ever hope to be. A rapid transition from breathable air to choking sulfur dioxide caught us off guard several times as we walked across the crater. I envision hell to be something like this crater.

This photo was taken with the lowermost rim of the fumarolic crater in the foreground and the summit in the background. Note the remanents of the once-luscious vegetation.

We descended into the crater along the rim shown here. From the rim we were able to access the rim of the fumarolic crater and get down to the floor. I remember that at one point my boot sank into the gypsum and very hot water seeped through my wool socks. I made a hasty exit from that spot.



Masaya caldera is situated just to the west of Managua. It is a complex caldera with several major craters within the confines of the caldera. This image shows gases rising from the active crater in 1973. The ridge in the background marks the caldera rim. For scale, there is a crowd of people in the flat area in the lower right but they are too small to be seen.

A few of my classmates and I hiked down from the hilltop where the last photo was taken to look into the yawning crater. Ordinarily, red lava could be seen in a small crater within this crater but its walls had recently collapsed so we just saw the rubble covering the lava lake.


1972 Earthquake Damage


Downtown Managua was completely destroyed in the quake. To make matters worse, the Somoza government found clever ways to profit off of the misery of the citizenry. This further sowed the seeds for the revolution which eventually drove Somoza from power.

The fault line ran right through the center of the city. This building straddled the fault so one side dropped as the other side rose.

Just a couple of blocks away from the other two pictures stands  the colonial cathedral. It sustained relatively little damage to its exterior, probably due to its stone construction. The only obvious damage is that the cross had toppled off of the left tower.