Car-Sized Boulder Crashes Down the Caliente Vent of Santa María Volcano (Mar 4, 2026)

A massive, car-sized boulder breaks loose and tumbles down the steep slopes of the Caliente vent on Guatemala’s Santa María volcano complex. Rockfalls like this are common at the active lava dome of Santiaguito, where unstable lava and volcanic debris frequently collapse from the growing dome. The Caliente vent is one of several active domes within the Santiaguito lava dome complex, which formed after the catastrophic 1902 eruption of Santa María. That eruption was one of the largest of the 20th century, ejecting enormous volumes of ash and pyroclastic material and devastating large parts of western Guatemala. Since 1922, the Santiaguito dome complex has been continuously active, slowly extruding lava and producing frequent explosions, ash plumes, and rockfalls. The Caliente vent in particular often sheds large blocks of unstable lava, which can tumble down the slopes exactly like the boulder seen in this video. Events like this illustrate the constant reshaping of the dome as new lava pushes upward and older material collapses under gravity.