When the Antarctic ice sheet loses mass, the pressure it exerts on the underlying solid Earth decreases. As the ice sheet becomes less heavy, the Earth’s surface is not pressed down as much as before and therefore slowly rises up. In some regions, this rebound process is much faster than previously thought and could stabilise areas of unstable ice retreat. How come? Keep reading to figure it out… ...[Read More]
The physical and social changes facing the mountainous populations of the Karakoram Range
View of Central Hunza valley with lush vegetation. Photo credit: Anas-Najam on unsplash.com.
As a child, Shakir remembers long extreme winters with heavy snowfall and dry blistering winds, where it was hard to play outside. He grew up in a village named Gulmit, located at an elevation of 2500 m, surrounded by the high snow caped mountains in the Karakoram Range in northern Pakistan. That was 30 years ago, when climate change was still not a cause of concern for the local people. Today, in ...[Read More]
Climate Change & Cryosphere – A brief history of A68, the world’s largest iceberg
In July 2017, the world’s largest iceberg known as A68 calved from the Larsen C Ice Shelf, located in the western Weddell Sea, Antarctica. Since then, A68 has lost two chunks of ice, A68-B and A68-C, but still remains a giant after more than 3 years. How did it feel to be the greatest, A68? Being the greatest With a length of 175 km and being about 50 km wide, this giant iceberg also appropriately ...[Read More]
Climatic drivers of permafrost mounds in North American peatlands
Figure 1. Palsas (permafrost mounds) at Stordalen Mire, Abisko, Sweden. Photo credit: Graeme Swindles.
Permafrost, or perennially frozen, peatlands are among the world’s largest terrestrial carbon stores and are particularly threatened by warming climates. Understanding how modern climate controls the distribution of permafrost peatlands is crucial for making confident predictions of their past and future extents. What are permafrost peatlands? Peatlands are wetlands that develop where cold, wet co ...[Read More]
Climate Change & Cryosphere – How the Chalaati Glacier (Georgian Caucasus) changed since the Little Ice Age
Chalaati Glacier is one of the largest glaciers in the Greater Caucasus and has undergone expansive mass loss. In this week’s blog post, Levan Tielidze tells us about Chalaati Glacier variations in the past centuries. His recent study was conducted based on surface exposure dating technique, dendrochronology (tree ring analysis), lichenometry, and satellite imagery. They found out that the Chalaat ...[Read More]
Climate Change & Cryosphere – Glacier retreat poses new challenges in the Central Andes
Glaciers on the slopes of San Jose Volcano, Maipo River Basin [Credit: Thomas Schatte].
When you hear of Chilean glaciers, you probably think about the large glaciers of Patagonia. However, glaciers can be found further north in Chile as well (see this previous post). While the melting of the Patagonian glaciers mainly affects the global human population by contributing to sea level rise, the retreat of glaciers in central Chile affects the local human population directly in terms of ...[Read More]
Exploring the hidden plumbing of glaciers with Cryoegg
Plumbing is something we take for granted: the pipes that bring us water to wash and drink, and the pipes that take the waste water away again. We see the taps and basins in our kitchen and bathroom – but the pipes are hidden away under the floor or inside the walls – and we mostly ignore them until there’s a leak or a blockage! It turns out that glaciers have plumbing too – and ...[Read More]
The future of Arctic sea ice
Figure 1: Sketch that shows the presence (in white, ‘ice covered’) and absence (in blue, ‘ice free’, i.e. less than 1 million km2 of sea ice) of Arctic sea ice for different levels of warming (X axis) and the different months of the year (Y axis), based on the extrapolation of observations. The estimated warming in 2018 is marked with ‘today’. Figure credit: Fig. 1 of Notz and Stroeve (2018).
The illustration above shows a sketch of the evolution of Arctic sea ice for different levels of warming and the different months of the year, based on the simple extrapolation of observations. A new study, in which I was involved, uses the latest available global climate models and shows that the Arctic Ocean could become practically ice free at the end of the summer for the first time before 205 ...[Read More]
Does debris cover offset glacier retreat in the Greater Caucasus?
Figure 1: Supra-glacial debris cover (SDC) change on the Elbrus Massif from 1986 to 2014. A SPOT-7 image is used as the background. Blue shows retreat of clean-ice parts. Clean ice in 1986 consists of the clean ice in 2014 (grey, transparent) plus clean-ice area that retreated between 1986 and 2014 (dark blue). Credit: Tielidze et al., 2020
In this week’s blog, Levan Tielidze tells us about supra-glacial debris cover change for the Greater Caucasus. His recent study indicates more than a doubling in the area of supra-glacial debris cover for the Elbrus Massif‘s glaciers from 1986 to 2014, the largest glacierized massif in the whole region. Glaciers on the western slope of the Elbrus Massif are affected by avalanches and thus ar ...[Read More]
What’s up on Thwaites Glacier?
Figure 1: Map showing the location of Thwaites Glacier in West Antarctica, as well as the main geographic focus of the 8 projects involved in the International Thwaites Glacier Collaboration (ITGC). Credit: ITGC website.
With the West Antarctic Ice Sheet currently losing ice at a fast pace, leading to sea-level rise, it is very important to better understand the processes by which this ice melting occurs. In this context, Thwaites Glacier is a very good case study of an accelerating glacier, which contributes substantially to sea-level rise, and for which a huge scientific collaboration effort has recently been se ...[Read More]