700 Million-Year-Old Snowball Earth Mystery Solved

In discussing the phenomenon known as “Snowball Earth,” Dr. Adriana Dutkiewicz, an ARC Future Fellow, paints a picture of a time when our planet was almost entirely encased in ice, with ice sheets stretching from the poles to the equator around 700 million years ago. This period, characterized by a dramatic drop in global temperatures, has long puzzled scientists regarding its cause.

During a field trip to the Ranges led by Professor Alan Collins of the University of Adelaide, Dr. Dutkiewicz and her team found inspiration to delve deeper into this historical mystery. They utilized EarthByte computer simulations from the University of Sydney to investigate the origins and extended duration of this ice age.

Named after Charles Sturt, a 19th-century explorer who ventured into central Australia, the Sturtian glaciation spanned from 717 to 660 million years ago. This ice age predates the rise of complex terrestrial plants and dinosaurs, marking a crucial chapter in Earth’s geological history.

The researchers propose a theory that the Sturtian glaciation was triggered by an unprecedented reduction in volcanic carbon dioxide emissions. This decrease was exacerbated by the weathering of vast volcanic rock formations in what is today Canada, a process that removes carbon dioxide from the atmosphere.

Dr. Dutkiewicz explains that the combination of reduced volcanic activity and the natural absorption of CO2 by weathering volcanic rocks may solve the riddle of how the Snowball Earth came to be. This period, lasting from 717 to 660 million years ago, represents a significant turning point in our planet’s history.

The enduring mystery of what caused the ice age to begin and end has intrigued scientists, but the exceptionally long duration of 57 million years has been particularly perplexing, according to Dr. Dutkiewicz.