Maly Semyachik (Russia): Recorded Eruptions and Historical Activity

Maly Semyachik is a caldera volcano located in Russia, standing at an elevation of 1,527 meters within a subduction zone and continental crust tectonic setting. According to the Smithsonian Global Volcanism Program, the volcano has a confirmed record of 23 eruptions spanning from deep prehistory up to the mid-20th century. The historical record includes activity analyzed via isotopic methods as well as direct historical observations.

Overview of Recorded Eruptions

The documented eruptive history of Maly Semyachik extends across multiple millennia. The earliest recorded eruption in the official record dates back to 7550 BCE. Throughout the subsequent millennia, activity occurred intermittently across various zones such as Meso-Semiachik, Ceno-Semiachik, and specific summit features including Crater VI (Troitsky) and the Troitsky Crater.

Of the 23 confirmed eruptions, 6 include recorded values on the Volcanic Explosivity Index (VEI). The largest recorded eruption reached a VEI of 4.0, which occurred at the Ceno-Semiachik (Crater VI–Troitsky) activity area with a start date indicated in the year 1550 CE. More recent recorded activity includes an eruption on December 5, 1952 CE, originating from the Troitsky Crater with a VEI of 2.0.

Chronological Distribution of Activity

Eruptive events at Maly Semyachik are distributed across numerous centuries BCE and CE. The official record documents confirmed events in the following periods:

• 76th century BCE
• 70th century BCE
• 62nd century BCE
• 59th century BCE
• 58th century BCE
• 55th century BCE
• 51st century BCE
• 47th century BCE
• 45th century BCE
• 35th century BCE
• 25th century BCE
• 23rd century BCE
• 18th century BCE
• 9th century BCE
• 7th century BCE
• 6th century BCE
• 14th century CE
• 16th century CE
• 19th century CE (featuring multiple events)
• 20th century CE (featuring multiple events)

The last known eruption in the structured profile occurred on December 5, 1952. The official database records no continuing eruption status for the volcano.