Costa Rica is a country forged by fire. Although only three volcanoes are currently active, there are more than 400 volcanic structures recognized by geologists in the country.Some are active and many are completely extinct, but all reveal the violent, volcanic past that shaped the land we inhabit today.
“Costa Rica has more than 400 volcanic structures in total, including both active and dormant ones. The rest are very old and already extinct,” explained María Martínez, a volcanologist at the Ovsicori Volcanic Geochemistry Laboratory.
These structures are not only found in the known mountain ranges. They also appear throughout the country, including Cocos Island, which is actually the tip of an ancient underwater volcano.
According to the expert, they can take many forms:
Explosion craters: generated by the interaction of magma with groundwater.
Volcanic relics: eroded mountains that were once active volcanoes.
“They are very old structures that time, rain, earthquakes, and even microorganisms have gradually crumbled. What remains are volcanic relics,” explained Martínez.
Why are there so many volcanoes?
The answer lies beneath the sea. Millions of years ago, Costa Rica and Panama did not exist as land.”The Pacific and Atlantic Oceans joined, and there was no connection between North and South America. But beneath those waters, active underwater volcanoes began to expel lava, gases, and ash,” the volcanologist emphasized.
“These underwater volcanoes functioned as emerging islands, like Cocos. Then, the lava from one island joined with that of another to form a single continental mass,” Martínez explained.This is how the current Central American Isthmus was gradually built, not only uniting the two continents but also allowing for a significant biological exchange.
“Thanks to this ‘bridge,’ animals and plants were able to move from north to south and vice versa, making the Central American Isthmus a very biologically rich area,” he explained.
Active and Dormant Volcanoes
Currently, Costa Rica maintains constant surveillance over three active volcanoes with recent eruptions: Poás, Turrialba, and Rincón de la Vieja.In addition, there are several volcanoes that, although they haven’t registered activity in years, are still considered dormant and active, with the potential to reactivate.
Among them are:
Irazú
Arenal
Barva
Miravalles
“Geologists consider all volcanoes that have had at least one eruption in the last 10,000 years to be active. Most of ours fit into that category, even though they are dormant now,” explained Martínez.Also, although some volcanic materials, such as ash, can be a disaster when exposed to humans, in tropics like Costa Rica, soil yields increase.
“Over time, water, light, and microorganisms increase soil yields by up to 40% or more over a three-year period, unlike in other drier places where that ash remains untransformed,” Martínez emphasized.
