Masaya Volcano

The Masaya Volcano (Volcán Masaya) is one of 18 distinct volcanic centers that comprise the Nicaraguan portion of the Central America Volcanic Arc.

Formed by the subduction of the Cocos Plate beneath the Caribbean Plate along the Middle America Trench, the volcanic belt runs from Volcán Tacaná in Guatemala to Volcán Irazú in Costa Rica.

Masaya is a complex volcano composed of a nested set of calderas and craters, the largest of which is the Las Sierras shield volcano and caldera. Within this caldera lies a sub-vent, a shield type composed of basaltic lavas and tephras and includes a summit crater.

The caldera was formed 2,500 years ago by a basaltic ignimbrite eruption. Inside this caldera, a new basaltic complex has grown from eruptions mainly on a semi-circular set of vents, including the Masaya and Nindiri cones.

The Nindiri cone hosts the pit craters of Masaya, Santiago, Nindiri and San Pedro. Observations in the walls of the pit craters indicate that there have been several episodes of cone and pit crater formation.

The volcano continually emits large amounts of sulfur dioxide gas from the active Santiago crater. Volcanologists study this and other signs to better understand the volcano's behavior and evaluate the impact of acid rain and the potential for health problems.

Although the volcano's recent activity has primarily been dominated by continuous degassing from an occasionally lava-filled pit crater, several discrete explosive events have occurred in the last 50 years.

Masaya Volcano National Park

Masaya Volcano National Park, located approximately 20 km (12 mi) south of the capital city of Managua, was established in 1979 as Nicaragua's first National Park.

Masaya Volcano National Park is one of Nicaragua's most popular tourist attractions because it offers the opportunity of direct contact with the crater area along with flora and fauna of the site.

The National Park has an area of approximately 54 sq km (20 sq mi), consisting of the Masaya Volcano: a volcanic caldera with two volcanoes and five craters in elevations between 100 - 630 m (328 - 2067 ft) above sea level.

The Santiago crater maintains a persistent lava lake with an incandescence that made it an object of veneration by the inhabitants of the area before the arrival of the Spanish colonizers. As a result, the crater is known locally as "La Boca del Infierno" or "The Mouth of Hell."