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Breaking the ice — Climate systems during Snowball Earth

Featuring image: modern sea ice at Antarctica. Denis Luyten (Wikimedia Commons), public domain (CC0).

Paper: Orbital forcing of ice sheets during snowball Earth

Authors: R. N. Mitchell, T. M. Gernon, G. M. Cox, A. R. Nordsvan, U. Kirscher, C. Xuan, Y. Liu, X. Liu, X. He

When you think about the Earth, you might imagine a blue and green globe orbiting the Sun. But the face of Earth has changed significantly over its life time and in the past, there were times when the Earth resembled more to a frozen, white snowball. Geologists, studying the climate during these cold epochs, found a connection between climate conditions in frozen oceans and variations of Earth’s orbit.

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Mercury on the Move

Featured image: Gravel and rocks crushed by the Greenland Ice Sheet.  Image courtesy PennStateNews, used with permission.

Paper: Large subglacial source of mercury from the southwestern margin of the Greenland Ice Sheet

Authors: Jon R. Hawkings, Benjamin S. Linhoff, Jemma L. Wadham, Marek Stibal, Carl H. Lamborg, Gregory T. Carling, Guillaume Lamarche-Gagnon, Tyler J. Kohler, Rachael Ward, Katharine R. Hendry, Lukáš Falteisek, Anne M. Kellerman, Karen A. Cameron, Jade E. Hatton, Sarah Tingey, Amy D. Holt, Petra Vinšová, Stefan Hofer, Marie Bulínová, Tomáš Větrovský, Lorenz Meire, Robert G. M. Spencer

The Greenland Ice Sheet is melting at an astounding rate as our planet continues to warm.  Mercury levels in the glacial meltwater traveling into the ocean are the highest levels ever measured in natural systems and rival heavily polluted rivers in Asia.  By measuring and tracing mercury in the meltwater, Hawkings and coworkers estimated that the Greenland Ice Sheet contributes up to 10% of all mercury found in Earth’s Oceans today.  Where is this mercury coming from within the Greenland Ice Sheet?  It is not actually coming from the ice itself, but rather the rocks that have been crushed under the immense weight of the Ice Sheet over thousands of years.

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How did valleys form on early Mars? Some say in ice…

Featured image: The Nirgal Vallis river valley on Mars as seen by the HRSC Camera onboard the European Space Agency’s Mars Express mission. Image credit: ESA/DLR/FU Berlin.

Paper: Valley formation on early Mars by subglacial and fluvial erosion.

Authors: Anna Grau Galofre, A. Mark Jellinek & Gordon R. Osinski.

“Some say the world will end in fire/ Some say in ice” begins the famous poem by Robert Frost. But what about how worlds begin? For years the theory of a “warm and wet” early Mars has been the conventional explanation for the vast valley networks formed billions of years ago that we can see on the surface today. Now, a new study suggests that at least some of these valleys could have formed under colossal ice sheets, in a distinctly more icy world.

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Iceland’s constantly changing landscape: A Book Review

Featured Image: Lake in a volcano’s crater at Mývatn, Iceland. Photo by Philipp Wüthrich on Unsplash.

Book: Iceland: Tectonics, Volcanics, and Glacial Features, Geophysical Monograph 247 (First Edition, 2020)
Author: Dr. Tamie J. Jovanelly
Figure Illustrations: Nathan Mennen
Additional Text: Emily Larrimore
Publisher: American Geophysical Union, John Wiley & Sons, Inc.

I have always wanted to go to Iceland and travel the countryside marveling at the island’s unique geology and icy wonder. Reading through Iceland: Tectonics, Volcanics, and Glacial Features by Dr. Tamie J. Jovanelly, I felt like I got my chance to tour Iceland; this time with a very experienced guide. Dr. Jovanelly has been to Iceland more than ten times since 2006 to explore and study and her familiarity with the place and the people who live there is engrained in this text.

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When space is time: evolving soil hydrology on glacial moraines

Featured image: The Stein Glacier in the central Swiss Alps, where the study was conducted. Left panel © Google, right panels CC BY Florian Lustenberger in Hartmann et al. 2020.

Paper: Field observations of soil hydrological flow path evolution over 10 millennia

Authors: Hartmann , A., Semenova, E., Weiler, M., & Blume, T.

The way water flows through soil and sediments can be incredibly diverse. In the simplest case, water flows uniformly through all of the pore space between grains. Most soils act very differently though. Water moves quickly through certain pathways and not at all through other areas. This preferential flow of water has important consequences for the ability of the soil to hold water, and for the movement of nutrients and contaminants. Understanding what factors affect the evolution of preferential flow pathways can help scientists better understand how soils work now, and how they will respond to human induced changes into the future.

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North Atlantic Ice Melt May Increase the Storminess of the Northern Hemisphere

Featured image of sea ice from Free-Photos on Pixabay

Paper: Rapid Cooling and Increased Storminess Triggered by Freshwater in the North Atlantic
Authors: M. Oltmanns, J. Karstensen, G. W. K. Moore, and S. A. Josey

Way up north in the Arctic Circle, sea ice and glaciers are rapidly melting and sending a massive amount of cold, fresh water into the North Atlantic Ocean. At first this influx of cold water may seem beneficial to offset the warming from climate change, but new research suggests that this meltwater from Greenland and the Arctic increases the number of winter storms that occur in the Northern Hemisphere.

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Evidence of pollution all the way to the poles

Featured Image: Lake Hazen in front of the Grant Land Mountains – photo courtesy Kyra St. Pierre, a co-author of the Sun et al. paper.

Paper: Glacial melt inputs of organophosphate ester flame retardants to the largest High Arctic lake

Authors: Sun, Yuxin, Amilia O. De Silva, Kyra A. St Pierre, Derek C. G. Muir, Christine Spencer, Igor Lehnherr, John J. MacInnis

Far from human habitation Lake Hazen sits north of the Arctic Circle surrounded by pristine, treeless mountains. But even there, the telltale chemical fingerprints of human pollution can be found.

Spring and summer in the far North are a short three-month period of reawakening, glacial melt, and permafrost thaw. During these months, meltwater transports anything that has collected on top of glaciers, like particles, nutrients, and contaminants deposited from the atmosphere, flowing down rivers and into glacial lakes. 

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Do melting glaciers release extra sediment?

Featured image: Pitztal Glacier, Austria by annca on Pixabay

Paper: Increased Subglacial Sediment Discharge in a Warming Climate: Consideration of Ice Dynamics, Glacial Erosion, and Fluvial Sediment Transport
Authors: Ian Delaney and Surendra Adhikari

The world’s glaciers are shrinking, sending great quantities of water downstream in a geologic instant. But new research shows a lesser-known effect of climate warming: a large increase in sediment released from melting glaciers that might rearrange the shape of Earth’s surface. Continue reading “Do melting glaciers release extra sediment?”