Ice-bound planets may still have seasons, climate fluctuations, and solar rhythms, according to a new study. For decades, scientists have portrayed Snowball Earth as a long hiatus in climate history, where movement and change are frozen in place.
During the coldest period in Earth’s history, continents, oceans, and even tropical regions were covered in ice, making meaningful climate change seem almost impossible.
However, according to a new study, University of Southampton I started drawing much more dynamic pictures.
Ancient rocks in Scotland reveal repeating climate patterns that persisted even at extreme global freezing temperatures, showing that the climate system was never completely silent.
rocks reveal hidden climate
Snowball Earth refers to an extreme situation ice age The Cryogenian Era (approximately 720 to 635 million years ago), when glaciers spread to lower latitudes and most of the world’s oceans were frozen.
Scientists once believed that these freezing conditions cut off contact between the atmosphere and ocean, suppressing seasonal changes and short-term climate cycles for millions of years.
The researchers tested that idea by analyzing finely layered rocks from the Gerberach Islands off the coast of western Scotland, which were formed during the Sturtian Ice Age, a global freeze that lasted about 57 million years.
Each thin layer, known as a varve, represents sediment deposited over a single year, creating one of the longest continuous annual climate records ever discovered from within the Snowball Earth glacier.
By measuring 2,640 geological formations in the Port Askaig Formation, the researchers reconstructed the environmental conditions from year to year, revealing clear evidence that climate rhythms persisted even under extreme global freezing temperatures.
“These rocks preserve the complete suite of climate rhythms we know today – yearly seasonthe solar cycle and the annual oscillation are all activated during Snowball Earth,” Professor Thomas Garnon said.
“This shows that the climate system has an innate tendency to oscillate given the slightest chance, even under extreme conditions.”
Sediment layers track seasons
When observed under a microscope, you can see alternating light and dark layers. A light layer was formed from the coarse sediment during the warm melting period.
During the cold season, fine particles settle out and form a black layer. Such structures accommodate seasonal freezing and thawing cycles.
Under the thick ice the water remained calm and deep. The floating ice released sediment as it partially melted. The ice also carried grain that fell into the water as it began to melt.
Such a pattern strongly supports annual deposit formation rather than random events.
“These rocks are extraordinary. They act like natural data loggers, recording year-to-year changes in climate during one of the coldest periods in Earth’s history,” said Dr. Chloe Griffin, lead author of the study.
“Until now, we didn’t know whether climate change on such timescales could exist in Snowball Earth, because no one had found such records within the glaciers themselves.”
Rock climate cycles
Statistical analysis of the layer thickness reveals repeated climate cycles lasting from just a few years to decades or even centuries.
Many of these patterns roughly match known solar cycles, including sunspot-driven rhythms, while others resemble ocean-atmosphere oscillations similar to modern El Niño-like systems.
The solar energy that reaches Earth changes slightly over time sunspot The cycle changes the amount of incoming radiation. Even small fluctuations can affect temperature, ice melting, and sediment movement.
The rock record shows strong signals corresponding to both multidecadal and century-scale solar rhythms, suggesting that sunlight continued to shape Earth’s climate even during deep global freezes.
Together, these findings indicate that climate change did not disappear, but continued on a smaller scale beneath the ice.
Ocean-atmosphere interaction is back
The climate model tested a variety of Snowball Earth conditions. Completely frozen oceans suppressed most climate change. But even in small areas with open tropical waters, climate change could recur.
“Our model showed that we don’t need a vast open ocean. Even a limited open ocean area in the tropics could have climate modes similar to those we see today, producing the kinds of signals recorded in the rocks,” said study co-author Dr. Ming-Ming Hu.
Open water has made possible the exchange of energy between air and ocean. These interactions cause temperature fluctuations, circulation pattern Similar to the modern climate system.
Earth’s polar ice destruction
Climate change did not dominate Snowball Earth. Evidence points to a short period of activity lasting several thousand years. Most of Snowball Earth remained frigid and stable.
“Our results suggest that this type of climate change is the exception rather than the norm,” Garnon said. “The background conditions on Snowball Earth were very cold and stable.”
“What we’re looking at here is a short-lived disruption lasting thousands of years, likely against the backdrop of a deeply frozen planet.”
Ancient rocks guide climate research
The rocks of Gerberach Island rank as one of the best-preserved records of snowball earth in the world. Their distinct layers and minimal disturbance allow scientists to read the frozen planet’s climate history almost from year to year.
“These deposits are some of the best preserved Snowball Earth rocks anywhere in the world,” said Dr. Elias Rugen. “Through them, you can read the history of Earth’s climate. frozen planet, In this case, one year at a time. ”
Understanding such extreme ancient climates can help scientists assess the resilience of the planet’s climate system. Even a near-total global freeze will not completely stop climate change, providing important lessons for the future.
“This research helps us understand how resilient and sensitive the climate system really is,” Professor Garnon said. “This shows that even in the most extreme conditions Earth has ever seen, the system can set in motion.”
The research will be published in a journal Earth and Planetary Science Letters.
Image credit: NASA
—–
Like what you read? Subscribe to newsletter We bring you fascinating articles, exclusive content, and the latest updates.
Please check it out earth snapThis is a free app provided by. Eric Ralls and Earth.com.
—–