Strong explosions at Pacaya volcano producing thick ash columns, Guatemala

Increased eruptive activity continues at the Guatemalan Pacaya volcano, with strong ash emissions and lava flows.

Moderate to strong explosions continue at the volcano, generating thick ash columns up to 4 km (13 120 feet) above sea level, moving N, NE, and NW to a distance of approximately 50 km (31 miles) on March 23, 2021.

Lava flows are 1 500 km (4 920 feet) long on the southwest flank and 500 m (1 640 feet) on the eastern flank.

Ashfall was reported in the villages of El Pepinal, San Francisco de Sales, Los Pocitos, Los Dolores, Mesillas Altas, Mesillas Bajas, Santa Elena Barillas, Villa Nueva and the capital city.

Image credit: INSIVUMEH

Image credit: INSIVUMEH. Acquired March 21, 2021

Credit: INSIVUMEH

Geological summary

Eruptions from Pacaya, one of Guatemala's most active volcanoes, are frequently visible from Guatemala City, the nation's capital.

This complex basaltic volcano was constructed just outside the southern topographic rim of the 14 x 16 km (8.7 x 9.9 miles) Pleistocene Amatitlán caldera. A cluster of dacitic lava domes occupies the southern caldera floor.

The post-caldera Pacaya massif includes the ancestral Pacaya Viejo and Cerro Grande stratovolcanoes and the currently active Mackenney stratovolcano.

The collapse of Pacaya Viejo between 600 and 1 500 years ago produced a debris-avalanche deposit that extends 25 km (15 miles) onto the Pacific coastal plain and left an arcuate somma rim inside which the modern Pacaya volcano (Mackenney cone) grew.

A subsidiary crater, Cerro Chino, was constructed on the NW somma rim and was last active in the 19^th century.

During the past several decades, activity has consisted of frequent strombolian eruptions with intermittent lava flow extrusion that has partially filled in the caldera moat and armored the flanks of Mackenney cone, punctuated by occasional larger explosive eruptions that partially destroy the summit of the growing young stratovolcano. (GVP)

Featured image credit: INSIVUMEH