Guatemala is defined by its powerful geology, situated along the Pacific Ring of Fire, a belt of intense seismic and volcanic activity. This location is due to the Cocos Plate subducting beneath the Caribbean Plate, which generates the heat and pressure required to fuel volcanic systems. These towering peaks are deeply woven into the country’s cultural and economic fabric, influencing indigenous myths and providing rich, fertile soil for agriculture. This constant presence prompts the question of how many volcanoes are currently active and pose a hazard.
How Geologists Define Volcanic Activity
The classification of a volcano as active, dormant, or extinct depends on the timescale used for assessment. Many volcanologists, including those at Guatemala’s National Institute of Seismology, Volcanology, Meteorology, and Hydrology (INSIVUMEH), use the Holocene epoch as a baseline. The Holocene began approximately 11,700 years ago, and any volcano that has erupted during this period is commonly considered active.
A volcano does not need to be actively erupting to be classified as active; it merely needs to show signs of a youthful magmatic system. These signs include increased seismic swarms beneath the cone, ground deformation, or the consistent emission of volcanic gases, such as sulfur dioxide, from fumaroles. A volcano that has not erupted in the last 10,000 years and is not expected to erupt again because its magma source has solidified is deemed extinct. The designation of “active” is a statement about a volcano’s potential to erupt again, making continuous scientific monitoring necessary.
The Current Number of Active Volcanoes in Guatemala
Guatemala has a total of 37 recognized volcanic structures shaping its highlands and Pacific coast. The specific number classified as currently active is much smaller, though the official count often settles on three. This figure reflects volcanoes that are not only capable of eruption but are presently showing measurable, sustained activity.
The classification is dynamic, meaning a volcano can shift from a long period of quiet to an active state, potentially changing the official count. However, the three peaks that consistently meet the criteria of having erupted recently and showing persistent unrest are the focus of national hazard planning. The remaining 34 volcanoes are classified as either dormant, meaning they have the potential to erupt again, or extinct. This small handful of active volcanoes requires constant observation due to their proximity to densely populated regions.
Guatemala’s Three Most Monitored Peaks
The three most consistently monitored and active volcanoes in Guatemala are Fuego, Pacaya, and the Santiaguito lava dome complex. These three sites are under intense observation due to their persistent activity and the direct threat they pose to nearby communities. Fuego, whose name translates to “Fire,” is one of the most consistently active volcanoes in Central America. It is characterized by frequent, moderate-to-strong explosions that occur several times per hour, generating ash plumes and sending incandescent material down its flanks toward nearby villages and the colonial city of Antigua.
Pacaya is known for its accessibility and effusive activity, involving the slow, steady extrusion of lava flows rather than violent explosions. This volcano, visible from Guatemala City, typically features small, incandescent spatter and is a constant source of fumarolic activity. The Santiaguito dome complex is a newer feature, having grown from the massive crater left by the 1902 eruption of the larger Santa María volcano. Santiaguito’s activity is marked by the slow, continuous growth of its lava dome, punctuated by frequent ash explosions that require constant vigilance, especially for the city of Quetzaltenango.