Posts Tagged "glaciers"

Could Cryoconites Hold the Secrets to Extraterrestrial Life?

Posted by on May 16, 2017 in All Posts, Featured Posts, Science | 1 comment

Could Cryoconites Hold the Secrets to Extraterrestrial Life?

Spread the News:ShareIn recent years, scientists have found other locations on planets, moons and exoplanets where life might exist. Different animals and organisms like tardigrades (eight-legged microscopic animals commonly known as water bears) have also been sent into space to explore the conditions for survival away from Earth. However, a recent paper published in the journal Contemporary Trends in Geoscience argues that we can look closer to home to understand survival strategies of extraterrestrial life. More concretely, the authors propose we look to glacier cryoconites, which are granular or spherical mineral particles aggregated with microorganisms like cyanobacteria, algae, fungi, tardigrades and rotifera (another type of multicellular, microscopic animal). Glaciers are among the most extreme environments on Earth due to the high levels of ultraviolet (UV) radiation received and the permanently cold conditions. These factors make them analogous to icy planets or moons. The associations of cryoconites and microorganisms on glaciers are held together in biofilms by extracellular polymeric substances (natural polymers of high molecular weight) secreted by cyanobacteria. They exist as sediment or in cryoconite holes (water-filled reservoirs with cryoconite sediment on the floor) on glacier surfaces. Cryoconites have been found on every glacier where researchers have looked for them. Cryoconite holes form due to the darkening of color (also termed a decrease in the albedo, or reflectivity of solar radiation) of cryoconite-covered surfaces. The darker color leads to greater absorption of radiation, with an associated warming and increasing melt rates. “Today we think that simple life forms might have survived on Mars in glacial refugia or under the surface. They can and could have evolved on Saturn and Jupiter’s icy moons,” Krzysztof Zawierucha, the lead author from Adam Mickiewicz University in Poland, shared with GlacierHub. “Imagine a multicellular organism, even a microscopic one, which is able to live and reproduce on an icy moon… It is a biotechnological volcano.” Organisms that live in glaciated regions are adapted to survive in extreme conditions and could provide insights into the survival strategies of extraterrestrial life. Some possess lipids (organic compounds that are not water-soluble), and produce proteins and extracellular polymeric substances that protect them from freezing and drying. Others are able to enter cryptobiotic states in which metabolic activity is reduced to an undetectable level, allowing them to survive extremely harsh conditions. The microorganisms in cryoconites cooperate and compete, affecting each other’s survival responses. Therefore, previous astrobiological studies, which have only been conducted on single strains of microorganisms, may not reflect the true survival mechanisms of these microorganisms. In addition, previous astrobiological studies involving some of these microorganisms used terrestrial or limno-terrestrial (moist terrestrial environments that go through periods of immersion and desiccation) taxa, such as moss cushions, which are less likely to be well-adapted to icy planets than their glacier-dwelling cousins. Tardigrades found in cryoconite have black pigmentation, which probably protects them from high UV radiation. Along with tardigrades, glacier-dwelling rotifera, specifically Bdelloidea, also possess a great ability to repair DNA damage, which confers high resistance to UV radiation. Both may also be better adapted to surviving in constantly near-freezing conditions than terrestrial forms. “So far, a number of processes analogous to those on Mars and other planets or moons have been found in the McMurdo Dry Valley as well as other dry valleys or brines in sea ice, both of which were considered to be extraterrestrial ecosystem analoguos. There is a great body of evidence that some bacteria and microscopic animals like tardigrades may survive under Martian conditions,” Zawierucha explained. “Of course, to survive does not mean to be active and to reproduce. Undoubtedly, however, it triggers consideration...

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Photo Friday: Send Us Your Glacier Selfies

Posted by on Apr 1, 2016 in All Posts, Art/Culture, Featured Posts, Images, News, Science, Tourism | 0 comments

Photo Friday: Send Us Your Glacier Selfies

Spread the News:ShareAt GlacierHub, we don’t just love science— we’re passionate about art and photography, too. We’ve featured work by Zaria Forman and Diane Burko, and each Friday we share photographs of glaciers and other mountain scenes. Now we’re excited to try something new: We’d like to invite our readers to share photographs that you’ve taken of glaciers. Specifically, we want your glacier selfies. President Barack Obama has already demonstrated this, in a video selfie with a glacier he shot in September last year in Kenai Fjords National Park in Alaska, during a trip to the Arctic focused on climate change. “Behind me is one of the most visited glaciers in Alaska,” Obama said. “It is spectacular, as you can see. And we’ve been able to spend the day out here, just learning more about how the glaciers are receding. It’s a signpost of what’s happening with a changing climate.” In that spirit— in recognition of the beauty of glaciers, their threatened status, and glaciers as places that humans interact with— we’d like to invite you to submit your own glacier selfies. We want selfies of you standing in front of, on, or near a glacier. This invitation is open to anyone who might visit a glacier: a researcher or scientist, tourist or traveler, or someone who lives near one. We will likely publish some of these images on GlacierHub. The photos (no videos, please) should be relatively recent, and should be true selfies. Please email submissions to glacierhub@gmail.com with a note giving us permission to publish them, along with some basic information: your name, the glacier’s name, the date it was taken, and what you were doing there. (And don’t take any risks while taking the selfie!) Please email us your photos by May 1– although if you have a trip to a glacier planned after that, let us know.  Spread the...

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Glacier Past Unveiled Through Sediments

Posted by on Oct 14, 2015 in All Posts, Featured Posts, Science | 0 comments

Glacier Past Unveiled Through Sediments

Spread the News:ShareResearchers have long used preserved sediment layers in glaciers as time records to understand the climate of the past. But now, researchers, publishing in Quaternary Science Reviews, have used lake sediments in glacier-fed Lake Hajeren in Svalbard to recreate glacier variability during the Holocene period. The sediments, which were deposited over millennia, have been undisturbed, allowing researchers to develop a continuous and full record of glaciers as early as 11,700 calibrated Before Present (BP). The dates were calculated using radiocarbon calibration, meaning that the dates have been compared to other radiocarbon samples. Atmospheric carbon varies over time, so it does not necessarily correspond to the current Gregorian calendar. By comparing different radiocarbon samples, researchers hope to develop a more accurate dating system. The researchers’ complete record revealed a number of new findings about the advance and presence of the Svalbard glacier. Sediments in Lake Hajeren indicated that between 3380 and 3230 cal BP there was a glacier advance that lasted more than 100 years. The glacier advance had never before been recorded. Researchers also noted that during the deglaciation period before 11,300 cal BP, glaciers in Svalbard remained, and that between 7.4 and 6.7 thousand cal BP, glaciers disappeared. It wasn’t until 4250 cal BP that glacier reformation began. The variability in glacier presence and formation can be attributed to pulses from the melting Laurentide Ice Sheet, episodes of cooling in the Atlantic and reduced isolation during summers. “These findings highlight the climate-sensitivity of the small glaciers studied, which rapidly responded to climate shifts,” the authors wrote. Their research contributes to a body of work looking to better understand the driving forces behind climate variability in the Arctic, the region most affected by climate change. The Arctic also has a disproportional impact on the global climate compared to other parts of the world. Arctic response to climate change can also be used to develop climate models that estimate the impacts of global warming. “The rapid response of the small Hajeren glaciers improves our understanding of climate variability on Svalbard, suggesting that the Holocene was punctuated by major centennial-scale perturbations,” the authors concluded. “As such, this study underlines the value of glacier-fed lake sediments in contextualizing Arctic climate dynamics.” Spread the...

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Roundup: Climate Park, Microbes and Variability

Posted by on Oct 12, 2015 in All Posts, Communities, Featured Posts, Science | 0 comments

Roundup: Climate Park, Microbes and Variability

Spread the News:SharePark in Norway Aims  to Raise Climate Awareness “Increased ice melting revealed in 2006–2007 many reminiscences of ancient human activity around ice patches near Mt Galdhøpiggen, Norway’s highest mountain peak. The public limited company ‘Klimapark 2469 AS’ was established to develop a heritage interpretation product and to study climate change. A 60-metre long ice tunnel is excavated in the ice patch Juvfonna, where guided walks and a display presenting climate change, archeology, Norse mythology, and glaciology are offered. […] An important outcome is the fruitful exchange of experiences, between public and private partners, tourism and science interests, amateurs and professionals, and between local, regional and national actors.” Read more about the park here. Microbial Life Thrives in Glacier Foreland Soil “To reveal temporal variability of archaeal and bacterial abundance, community structure, as well as microbial biomass and activity, soils of different ages (young, intermediate, mature) were sampled along a glacier foreland in the Austrian Central Alps, at the beginning (summer) and at the end (autumn) of the plant growing season. […] Our results indicate that temporal variations of microbial activities, biomass, and abundance in alpine glacier foreland soils distinctly increased along with the age of the soils and highlight the importance of sampling date for ecological studies.” Read the full study here. Sediments in Lake Reveals Clues About Glacier Variability “The Arctic is warming faster than anywhere else on Earth. Holocene proxy time-series are increasingly used to put this amplified response in perspective by understanding Arctic climate processes beyond the instrumental period. However, available datasets are scarce, unevenly distributed and often of coarse resolution. Glaciers are sensitive recorders of climate shifts and variations in rock-flour production transfer this signal to the lacustrine sediment archives of downstream lakes. Here, we present the first full Holocene record of continuous glacier variability on Svalbard from glacier-fed Lake Hajeren. This reconstruction is based on an undisturbed lake sediment core that covers the entire Holocene and resolves variability on centennial scales owing to 26 dating points.” Take a look at the study here. Spread the...

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A Dying Glacier, a Drought-Stricken Village, and a Good View

Posted by on Jun 25, 2015 in Adaptation, All Posts, Communities, Experiences, Featured Posts | 0 comments

A Dying Glacier, a Drought-Stricken Village, and a Good View

Spread the News:ShareIn the course of researching my new book, “Fire and Ice: Soot, Solidarity and Survival on the Roof of the World”, I traveled to many communities living in the shadow of retreating snow and ice. I talked to Sherpa villagers who fear potential glacial lake outburst floods in Nepal’s Khumbu Valley, and with Naxi people adapting to drought conditions not far from the increasingly bare flanks of the Jade Dragon Snow Mountain in China’s Yunnan Province. But nowhere did I find the consequences of the Himalaya’s shrinking glaciers and snowfields as stark or sobering as in Kumik, a cluster of 39 households hugging a hillside in northwest India. Kumik is one of the oldest communities in the remote Zanskar Valley, and the first there to be abandoned due to a changing climate. Zanskar lies in the “rain shadow” formed by the Great Himalayan Range, where the only source of water – and therefore life – is melting snow and ice. The villagers of Zanskar long ago developed a sophisticated water-sharing system, to irrigate their fields of barley, peas, wheat and fodder grasses. But physics threatens to overwhelm this cultural ingenuity. “There are loud indicators that these glaciers are melting,” Shakeel Romshoo, a glaciologist at the University of Kashmir, told me. He has studied glaciers in Zanskar and other parts of the state of Jammu and Kashmir since the mid-1980s. “Out of 365 glaciers in the Zanskar region that were there in 1969, about 6 of these glaciers are not there.” As in, completely gone. “I would say, all the glaciers I have seen, they are showing the recession.” Ulrich Kamp, of the University of Montana, measured thirteen glaciers in Zanskar, combining field measurements of glacier topography with thermal imaging and remote sensing data. “Most of the glaciers in the Greater Himalaya Range in Zanskar are receding since at least the 1970s,” he and his colleagues concluded. Kumik is on the sharp edge of this troubling trend. Its sole lifeline is one small stream coursing down from the glacier-capped mountain of Sultan Largo. This lifeline is frequently severed by the double whammy of declining snowfall and earlier, warmer springs. The stream now often dries up by August, before the harvest. Ishay Paldan, the oldest resident of Kumik, has watched as the snowfields and small glaciers on the mountains above have steadily retreated over the course of his lifetime. “When I was a child, we had no problems with water,” he told me on my first visit. The view from his window shows just how much things have changed: the snowline that once almost came down to the edge of Kumik is now several kilometers distant. Kumik’s chronic state of drought became so acute in the summer of 2000 that the entire community gathered and made a painful decision. They would leave their ancient homes, and start over somewhere else. The government offered them a dusty, wind-scoured patch of desert – a couple miles and almost a thousand feet below – where they could start over. So they began to dig a canal, five miles long, to bring water from the Lungnak River. They gathered stones and mixed mud bricks. They started to build a new village from scratch, hoping to green this no-man’s-land long known as Marthang, “the red place.” Since my first visit in 2008, I have spent many happy days with the people of Kumik, listening to their stories in the old village they are slowly leaving, and working alongside them in the new one they are slowly coaxing from the desert floor. The villagers are...

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