Snowball Earth

News: A new study in Earth and Planetary Science Letters has reported evidence that shorter climate cycles still operated during at least one phase of this snowball earth.

About Snowball Earth

• Snowball Earth refers to a period during the Cryogenian Period, about 720–635 million years ago, when scientists believe that most of the Earth was covered with thick ice.
• During this time, glaciers may have reached tropical regions, and the oceans were likely frozen over.
• Because the oceans were mostly covered by ice, the normal exchange of heat, sunlight, and gases between the ocean and atmosphere would have been greatly reduced.
• Reason: Scientists think this extreme glaciation happened due to changes in carbon dioxide levels, sunlight, and Earth’s climate system.

About New Scientific Findings

• A study in Earth and Planetary Science Letters analysed 2,640 sediment layers from the Port Askaig Formation on the Garvellach Islands in Scotland and identified them as yearly layers called varves.
• The thickness of these layers showed climate cycles matching solar cycles of about 9–11 years and 60–150 years, along with shorter 2–5 year variations.
• Climate simulations of Snowball Earth also showed similar short-term changes, suggesting the climate kept fluctuating even when Earth was mostly frozen.