Buckle Island

Geography & Climate

Buckle Island is located in Antarctica, within the Balleny Hotspot Volcano Group of the broader Antarctic-Scotia Volcanic Regions. Situated at 66.78° S, 163.25° E in the Southern Hemisphere, the volcano lies within a polar climate zone. With a summit elevation of 1,239 meters above sea level, Buckle Island is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Buckle Island is situated along a rift zone, where tectonic plates are pulling apart. As the crust thins and fractures, magma rises to fill the gap, creating volcanic activity. Rift volcanism typically produces more fluid lava flows rather than explosive blasts, which means communities near Buckle Island in Antarctica generally face slower-moving hazards like lava flows and ground fissures rather than sudden pyroclastic events. However, rift volcanoes can still generate significant ash emissions and gas releases that affect local air quality. The dominant rock type is trachybasalt / tephrite basanite, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.

Eruption History Summary

Buckle Island has 2 recorded eruptions in the geological database, spanning from 1839 CE to 1899 CE. The most powerful recorded event was an explosive event producing ash plumes up to several kilometers in 1899 CE, reaching VEI 2 on the Volcanic Explosivity Index. These eruptions span roughly 60 years of volcanic history.

GVP Reference Summary

Buckle Island is in the center of a 160-km-long chain of volcanic islands forming the Balleny Islands off the coast of Antarctica's Victoria Land. The islands are located at the southern end of a submarine ridge system that extends north to New Zealand, but is offset by the Indian-Antarctic ridge system. The elongated, 21-km-long island is capped by an gently sloping icecap that descends steeply to the sea between rocky cliffs. Dark eruption columns were reported during 1839 and 1899, but no detailed geological studies exist for the Balleny Islands volcanoes.

— Smithsonian Institution, Global Volcanism Program