Kanaga (United States): Recorded Eruptions and Historical Activity

Kanaga is a stratovolcano situated in the United States at a tectonic subduction zone with an intermediate crust depth of 15 to 25 kilometers. Standing at an elevation of 1,307 meters, the volcano has a recorded history of 18 confirmed eruptions spanning from early isotopic records dating back to approximately 7300 BCE through modern observation methods in 2023.

Eruption History and Chronology

The official record for Kanaga includes 18 confirmed eruptions distributed across various centuries, documented through a combination of calibrated isotopic techniques (such as 14C dating) and historical observations including reports and seismicity. The earliest recorded activity in the collection dates back to approximately 7300 BCE, carrying an estimated start year uncertainty of 500 years. Subsequent prehistoric and historical activity is documented across multiple centuries BCE and CE.

Methodologies for recording eruptions shift over time from absolute dating and isotopic analyses to direct human observation and modern seismic monitoring instruments. For instance, an eruption on February 18, 2012, involved an east-west fissure at the summit crater documented via reported observations, reaching a Volcanic Explosivity Index (VEI) of 2.0. A more recent confirmed eruption occurred on December 18, 2023, identified through seismicity methods with a VEI of 1.0.

Distribution of Recorded Eruptions by Century

The 18 confirmed eruptions span numerous centuries, reflecting varying levels of documentation and activity over millennia:

• 73rd century BCE: 1 eruption
• 47th century BCE: 1 eruption
• 23rd century BCE: 1 eruption
• 22nd century BCE: 1 eruption
• 19th century BCE: 1 eruption
• 16th century BCE: 1 eruption
• 2nd century CE: 1 eruption
• 9th century CE: 1 eruption
• 12th century CE: 1 eruption
• 14th century CE: 1 eruption
• 18th century CE: 1 eruption
• 20th century CE: 5 eruptions
• 21st century CE: 2 eruptions

The largest recorded Volcanic Explosivity Index (VEI) for the volcano is 2.0, with VEI values documented across a subset of the confirmed eruptions in the official dataset.