Makushin is a stratovolcano located in the United States, positioned in a subduction zone setting with an intermediate crust measuring 15 to 25 kilometers. Rising to an elevation of 1,800 meters, the volcano has a documented history of 19 confirmed eruptions spanning from prehistoric periods to the late 20th century. According to the Smithsonian Global Volcanism Program record, the earliest recorded eruption in the database dates back to 6650 BCE, while the latest confirmed eruption occurred on January 30, 1995.
Eruption History and Chronology
The historical and prehistoric record of Makushin includes 19 confirmed eruptions distributed across various centuries, evaluated using a range of evidence methods including uncalibrated radiocarbon isotopic dating, tephrochronology correlation, and direct human observations. Out of the 19 confirmed eruptions, 13 have associated Volcanic Explosivity Index (VEI) values recorded in the official database.
Prehistoric activity is established through scientific dating techniques. For instance, an early recorded eruption is dated to 6650 BCE with an estimated start year uncertainty of 200 years, using uncalibrated 14C isotopic evidence. Another significant event occurred around 6100 BCE, carrying an uncalibrated radiocarbon uncertainty of 50 years and reaching a Volcanic Explosivity Index of 5.0, which stands as the largest recorded VEI for this volcano in the official dataset. Later prehistoric activity includes an eruption around 550 BCE with a start year uncertainty of 900 years, identified through tephrochronology correlation.
As observational methods advanced, the record shifted toward direct human accounts. Documented historical activity includes an eruption on July 2, 1865, noted via reported observations. The most recent confirmed activity in the official record took place on January 30, 1995, also documented through reported observations with a recorded VEI of 1.0.
Distribution of Recorded Eruptions by Century
The confirmed eruptions span multiple centuries BCE and CE, reflecting intermittent activity across thousands of years:
- 67th century BCE: 1 recorded eruption
- 61st century BCE: 1 recorded eruption
- 37th century BCE: 1 recorded eruption
- 18th century BCE: 1 recorded eruption
- 6th century BCE: 1 recorded eruption
- 12th century CE: 1 recorded eruption
- 18th century CE: 1 recorded eruption
- 19th century CE: 4 recorded eruptions
- 20th century CE: 8 recorded eruptions
Image credits
- Henry Wood Elliott — Wikimedia Commons source — Public domain
Sources and further context
Official datasets support the event-specific facts.