Mount Takahe, snow-covered shield volcano located in Marie Byrd Land, West Antarctica, near the edge of the Thwaites Glacier. Mount Takahe, whose summit sits 11,352 feet (3,460 meters) above sea level, is roughly conical in shape, extending approximately 18 miles (29 km) across. The volcano’s caldera at its summit is about 5 miles (8 km) wide. The volcano is part of the West Antarctic Rift System and could be the largest in total estimated rock volume of the 18 known volcanoes in this region of West Antarctica. With an estimated volume of about 1,324 cubic miles (5,520 cubic km), which takes into account an estimate of the volcano’s volume beneath the West Antarctic Ice Sheet, it is comparable in size to Mount Kilimanjaro in Tanzania. Mount Takahe is named for the South Island takahe (Porphyrio hochstetteri), an endangered flightless bird from New Zealand that was also the moniker for a U.S. Navy LC-47 aircraft used by members of the Marie Byrd Land traverse party during the Antarctic expeditions of 1957–58.
Mount Takahe’s last known eruption took place in roughly 5550 bce. In a 2017 study, chemical compounds found in ice cores taken from more than 11,155 feet (3,400 meters) below the surface of the West Antarctic Ice Sheet showed evidence of a series of volcanic eruptions that occurred over a 192-year period. Scientists suggested that these eruptions coincided with an interval of rapid climate change that paralleled a period of accelerated deglaciation that began about 17,700 years ago (see also glacier). They also noted that the eruptions depleted the ozone layer above Antarctica and led to dramatic climate changes that affected the Southern Hemisphere, including a shift in the westerly winds toward the South Pole and the fallout of hydrofluoric acid and toxic metals that reached as far as the southern part of South America.