Cleveland (United States): Recorded Eruptions and Historical Activity

Mount Cleveland is a stratovolcano located in the United States, standing at an elevation of 1,730 meters within a subduction zone setting characterized by intermediate crust (15-25 km). According to the Smithsonian Global Volcanism Program, the volcano has a documented history of 22 confirmed eruptions spanning across the 19th, 20th, and 21st centuries CE. The earliest recorded eruption in this official dataset began on July 2, 1893 CE, and the latest confirmed eruption concluded on June 1, 2020 CE.

Historical Eruption Timeline and Century Breakdown

Official records show that documented eruptive activity at Cleveland has increased across successive centuries, reflecting a combination of geological output and improvements in observation methods. The confirmed eruptions are distributed across three centuries:

• 19th century CE: 2 confirmed eruptions (beginning with the July 2, 1893 CE event)
• 20th century CE: 9 confirmed eruptions (including events such as the July 12, 1984 CE eruption with a Volcanic Explosivity Index of 1.0, and the May 5, 1997 CE eruption with a Volcanic Explosivity Index of 2.0)
• 21st century CE: 11 confirmed eruptions (including the June 25, 2009 CE eruption with a Volcanic Explosivity Index of 2.0, and the June 1, 2020 CE eruption with a Volcanic Explosivity Index of 3.0)

Understanding the Volcanic Explosivity Index (VEI)

The Volcanic Explosivity Index (VEI) provides a relative scale to describe the size of explosive volcanic eruptions based on factors such as volume of products and eruption cloud height. Within Cleveland's official record of 22 confirmed eruptions, 18 have associated VEI observations. The largest recorded VEI in this dataset is 3.0. For example, the confirmed eruption on June 1, 2020 CE, reached a VEI of 3.0, while earlier events such as the July 12, 1984 CE eruption recorded a VEI of 1.0, and the May 5, 1997 CE and June 25, 2009 CE eruptions each recorded a VEI of 2.0. Observations for these historical events primarily rely on reported sightings and monitoring methods documented by the Smithsonian Global Volcanism Program.