Cayambe (Ecuador): Recorded Eruptions and Historical Activity

Cayambe is a compound volcano situated in Ecuador, rising to an elevation of 5,790 meters within a subduction zone and continental crust setting exceeding 25 kilometers in thickness. According to the Smithsonian Global Volcanism Program, the volcano has a recorded history comprising 22 confirmed eruptions. The earliest recorded eruption in the structured collection dates back to 1800 BCE, while the latest recorded activity includes an eruption spanning from February 1785 to March 1786.

Eruption History and Chronology

The historical and prehistorical activity of Cayambe is documented across multiple centuries, utilizing evidence methods such as tephrochronology and reported historical observations. The confirmed eruptions span various centuries, showing intermittent activity across BCE and CE periods. The largest recorded Volcanic Explosivity Index (VEI) for the volcano is 4.0, which was documented during an eruption on the north flank of the main summit in 1570 CE.

Representative records from the official database illustrate the range of documented events:

• 1800 BCE (?): Confirmed eruption identified via tephrochronology correlation.
• 460 BCE (?): Confirmed eruption identified via tephrochronology correlation.
• 170 CE (?): Confirmed eruption identified via tephrochronology correlation.
• 1570 CE (?): Confirmed eruption on the north flank of the main summit with a recorded VEI of 4.0, determined via tephrochronology correlation.
• February 1785 to March 1786: Confirmed eruption on the upper southeast flank with a recorded VEI of 2.0, documented through reported observations.

Distribution of Recorded Activity by Century

The 22 confirmed eruptions at Cayambe are distributed unevenly across different centuries of the official record. The chronology includes activity in the 18th, 17th, 13th, and 6th centuries BCE, as well as the 1st, 2nd, 3rd, 5th, 9th, 11th, 13th, 15th, and 16th centuries CE. Four of the confirmed eruptions feature recorded Volcanic Explosivity Index (VEI) values, with 4.0 being the maximum observed index.