Volcanic Explosivity Index
On 13 December 1921, Cordón Caulle began a sub-plinian eruption, with a high plume, periodic explosions and seismicity. The eruption had a Volcanic Explosivity Index of 3 and ended in February 1922. In 1929 and 1934 the Cordón Caulle had fissure eruptions, both with an estimated Volcanic Explosivity Index of 2.