Rabaul (Papua New Guinea): Recorded Eruptions and Historical Activity

Rabaul is a caldera volcano located in Papua New Guinea at a tectonic subduction zone on continental crust more than 25 kilometers thick. Standing at an elevation of 688 meters, the volcano features a recorded history comprising 19 confirmed eruptions spanning from the 7th century CE through the 21st century CE. According to official records from the Smithsonian Global Volcanism Program, the earliest recorded eruption occurred in 683 CE, and the latest confirmed eruption began on July 7, 2014.

Overview of Recorded Eruptions

The historical record for Rabaul includes 18 eruptions with documented Volcanic Explosivity Index (VEI) ratings, reaching up to a maximum recorded VEI of 6.0. The records demonstrate activity distributed across multiple centuries, captured through a combination of calibrated isotopic evidence for early events and direct human observations for later centuries.

Representative examples of recorded activity include:

• 683 CE: An early confirmed eruption characterized by a VEI of 6.0, identified using calibrated 14C isotopic evidence with a start year uncertainty of 2 years.
• 1850 CE: A confirmed eruption in the Sulfur Creek activity area starting around July 2, 1850, with a VEI of 2.0, documented via reported observations.
• 1943 CE: An eruption at the Tavurvur activity area that spanned from November 24, 1943, to December 23, 1943, reaching a VEI of 2.0.
• 2006–2010 CE: A sustained period of activity at Tavurvur beginning on August 11, 2006, and ending on January 31, 2010, rated at a VEI of 4.0.
• 2014 CE: A confirmed eruption at Tavurvur that started on July 7, 2014, and concluded on September 18, 2014, with a VEI of 3.0.

Distribution of Eruptions by Century

Official records catalog Rabaul's 19 confirmed eruptions across various centuries. The distribution highlights intervals of documented activity ranging from single events in ancient centuries to multiple episodes in recent decades:

• 7th century CE: 1 eruption
• 15th century CE: 1 eruption
• 18th century CE: 2 eruptions
• 19th century CE: 2 eruptions
• 20th century CE: 6 eruptions
• 21st century CE: 7 eruptions

This chronological spread reflects a mix of historical reporting granularity and varying frequency in the documented record over time.