Roundup: Catastrophe on Mt. Ararat, Albedo Effect in the Alps, and Meltwater in Greenland

Reappraising the 1840 Ahora Gorge Catastrophe

Mt. Ararat is seen from the northeast in 2009. (Source: Wikimedia Commons)

From Geomorphology: “Ahora Gorge is a 400 m deep canyon located along the North Eastern flank of Mt. Ararat (Turkey), a compound volcanic complex covered by an ice cap. In the past, several diarists and scientific authors reported a calamitous event on July 2, 1840, when a landslide triggered by a volcanic eruption and/or an earthquake obliterated several villages located at the foot of the volcano. The reasons and effects of this Ahora Gorge Catastrophe (AGC) event have been obscure and ambiguous. To reappraise the 1840 catastrophe and the geomorphic evolution of the Ahora Gorge, we used high-resolution satellite images, remote sensing thermal data supplemented by observations collected during two field surveys.”

Albedo Effect in the Swiss Alps

The Oberaar glacier is seen from Oberaar, Bern, Switzerland in 2010. (Source: Simo Räsänen/Wikimedia Commons)

From The Cryosphere: “Albedo feedback is an important driver of glacier melt over bare-ice surfaces. Light-absorbing impurities strongly enhance glacier melt rates but their abundance, composition and variations in space and time are subject to considerable uncertainties and ongoing scientific debates. In this study, we assess the temporal evolution of shortwave broadband albedo derived from 15 end-of-summer Landsat scenes for the bare-ice areas of 39 large glaciers in the western and southern Swiss Alps. […] Although a darkening of glacier ice was found to be present over only a limited region, we emphasize that due to the recent and projected growth of bare-ice areas and prolongation of the ablation season in the region, the albedo feedback will considerably enhance the rate of glacier mass loss in the Swiss Alps in the near future.”

Glacier Meltwater Impacts in Greenland

An iceberg floats in Franz Josef Fjord, Greenland (Source: Wikimedia Commons)

From Marine Ecology Progress Series: “Arctic benthic ecosystems are expected to experience strong modifications in the dynamics of primary producers and/or benthic-pelagic coupling under climate change. However, lack of knowledge about the influence of physical constraints (e.g. ice-melting associated gradients) on organic matter sources, quality, and transfers in systems such as fjords can impede predictions of the evolution of benthic-pelagic coupling in response to global warming. Here, sources and quality of particulate organic matter (POM) and sedimentary organic matter (SOM) were characterized along an inner-outer gradient in a High Arctic fjord (Young Sound, NE Greenland) exposed to extreme seasonal and physical constraints (ice-melting associated gradients). The influence of the seasonal variability of food sources on 2 dominant filter-feeding bivalves (Astarte moerchi and Mya truncata) was also investigated. Results revealed the critical impact of long sea ice/snow cover conditions prevailing in Young Sound corresponding to a period of extremely poor and degraded POM and SOM.”

Read More on GlacierHub: 

Rising Temperatures Threaten Biodiversity Along the Antarctic Peninsula

Mongolia’s Cashmere Goats Graze a Precarious Steppe

United Nations Steps for Building Functional Early Warning Systems

Please follow, share and like us:
error

Roundup: Project BlackIce, Larvae, and Nature Study Retraction

Project BlackIce Examines Microbes and Glacial Albedo

From Project BlackIce: “Algae can protect themselves before damaging UV-radiation by darker pigmentation which results in a darkening of the surface which is increasing the availability of liquid water, hence again the growth of microbial communities. This biologically induced impact on albedo is called ‘bioalbedo’ which has never been taken into account in climate models. So far we have most information on bioalbedo on arctic glaciers which is quite a shame that literally nothing is known about alpine glaciers. The aim of this interdisciplinary study is a quantification and qualification of organic and inorganic particles on an alpine glacier (Jamtalferner).”

Learn more about Project BlackIce here.

Photo of Project BlackIce logo.
The Project BlackIce logo (Source: Project BlackIce).

Patterns in Larvae Size in Glacial Streams

From Schütz & Füreder: “Glacially influenced alpine streams are characterized by year-round harsh environmental conditions. Only a few, highly adapted benthic insects, mainly chironomid larvae (genus Diamesa) live in these extreme conditions. Although several studies have shown patterns in ecosystem structure and function in alpine streams, cause–effect relationships of abiotic components on aquatic insects’ life strategies are still unknown. Sampling was performed at Schlatenbach, a river draining the Schlatenkees (Hohe Tauern NP, Austria)… This is the first study to show that harsh conditions in these environments (low temperatures, high turbidity and flow dynamics) may exclude many taxa, but favor other, highly adapted species, when their essential needs (food quality and quantity) are guaranteed.”

Learn more about the study here.

Image of the Diamesa cinerella larva
The Diamesa cinerella larva. Numbers represent the sites where measurements were taken (Source: Schütz & Füreder).

 

Nature Study on Asian Glaciers Retracted

From Nature: “In this article, I estimated net glacial melt volumes on the river-basin scale from long-term precipitation and temperature records (1951–2007), taking into account the various mass contributions from avalanching, sublimation, snow drifting and so on… I estimated the second meltwater component (the additional contribution from glacier losses) as −0.35 to −0.40 metres water-equivalent per decade based on a global compilation of long-term mass-balance observations (from table 2 in ref. 32 of the Article). In this table, losses are described as ‘decadal averages (millimetres water equivalent)’ but the units are actually intended to be decadally averaged annual values. Hence, the loss components of total meltwater that I used in my calculations are too small and the summed meltwater volumes reported here should be larger. Asia’s glaciers are thus regionally a more important buffer against drought than I first stated, strengthening some of the conclusions of this study but also altering others. I am therefore retracting this article.”

Learn more about the retraction here.

A figure from the retracted study.
A figure from the retracted study (Source: Nature/Twitter).

 

 

Please follow, share and like us:
error

Small Particles Have Big Impact on Glacial Health

A recent study by Heidi Smith et al. in the desolate McMurdo Dry Valleys of Antarctica has shown that microbial life in biofilms is present across a large part of the region’s ice, suggesting that the stability of polar ice can be influenced by even the smallest of organisms.

Biofilms—thin, slimy bacterial layers that can adhere to a surface—were discovered in conjunction with the windblown dust that accumulates on snow and ice called cryoconite. The research found that a combination of biofilms and cryoconite is capable of enhancing the rate of glacial melting, meaning that the planet may be more vulnerable to sea level rise than previously imagined.

As an important component in the planet’s hydrological and carbon cycles, glacial melting affects sea levels and the chemistry of our oceans. This meltwater enhances the movement of fluids from terrestrial environments to oceans, as well as the transport of nutrients to aquatic ecosystems. In the McMurdo Dry Valleys, the activity of microorganisms on the glacier surface enables the accumulation of organic matter on minerals found in the ice’s dusty cryoconite layers. This relationship results in the darkening of ice over time, making it less efficient at reflecting incoming sunlight than it would be normally. As most of Antarctica’s ice lies atop the continental landmass,  increased melting at the Earth’s southern pole may lead to an appreciable rise in global sea levels.

A view of the Canada Glacier involved in the field study. (Source:Joe Mastroianni, National Science Foundation)
A view of the Canada Glacier involved in the field study (Source: Joe Mastroianni/National Science Foundation).

Prior research in alpine glacial environments and on the Greenland Ice Sheet (Langford et al. 2010) established a correlation between biofilm development and the darkening of cryoconite particles, pointing towards the synergistic possibility of biologically enhanced rates of melting. Until the recent publication of key research by Heidi Smith et al., the role of biofilms in Antarctica was largely unknown.

In conversation with GlacierHub, Smith stated that “the role of biofilms in different glacial locations has not been explored.” She added “due to differences in environmental pressures (temperature extremes, nutrient availability, levels of UV radiation, and rates of flushing), it is possible that the role of biofilms in glacial surface processes varies by location.” Smith’s team was able to establish the precedence of biofilms at extreme southern latitudes in their research and also contributed to the larger body of scientific evidence supporting the role of microbes in influencing reflectivity, otherwise known as albedo, of glaciers.

Smith and her research colleagues employed a variety of methods to investigate the interactions between the biological and mineralogical components of Antarctic ice. Microbial species were identified in the lab via pyrosequencing (which determines the order of nucleotides in DNA by detecting the release of the pyrophosphate ion) as well as epifluorescent microscopy (which utilizes a compound microscope equipped with a high-intensity light source). The team’s research yielded four unique bacterial components in biofilms found in cryoconite holes. Interestingly, Smith told GlacierHub that “while some organisms identified in this study have also been found in cryoconite holes from the Greenland Ice sheet, the relative abundance of individual organisms in each of these locations appears to be geographically distinct.”

transantarctic_mountain_hg
The Trans-Antarctic Mountains, a prominent feature in Northern Victoria Land (Source: Hannes Grobe/Alfred Wegener Institute).

The primary region for fieldwork and sampling for the study was an ice-lidded cryoconite hole on the Canada Glacier, located near Victoria Land, Antarctica. When asked about why the team chose to work in this isolated region, Smith replied: “There are previous studies from this region that have focused on cryoconite hole geochemistry, rates of microbial activity and microbial assemblage composition; therefore, we could place samples from this study into a larger framework.”

Following fieldwork on the glacier, subsequent laboratory analysis showed that enriched levels of nitrogen and carbon isotopes were present when Bacteroidetes (one of the four main bacterial phyla) was incubated in the presence of compounds such as sodium bicarbonate and ammonia. These findings point to the conclusion that the spatial organization within a microbially rich biofilm can promote the transfer of chemical compounds and nutrients. Such a result serves to validate the hypothesis that the formation of biofilms may enhance the accumulation of organic material on cryoconite minerals, thus affecting the color and reflectivity of glacial surfaces.

The study concluded that not only are biofilms present in nearly thirty-five percent of cryoconite holes in Antarctica, but that due to regional differences in the distribution of black carbon between the study region and the Arctic, biofilm may play a heightened role (relative to the northern hemisphere) in promoting biological activity on glaciers. Smith added, “In addition to influencing levels of glacial melt, biofilms have the potential to alter marine ecosystems through glacial runoff.” Additionally, she said, “There is also the potential for increases in CO2 release, which contributes to the rising temperatures globally.”

The research by Smith and her team points to important feedback loops with future increases in temperature, as longer melt seasons will stimulate biofilm communities, which alone have the capacity to increase rates of glacial melt. If temperatures continue to rise, the positive feedback between a warmer climate and lower reflectivity on ice surfaces may lead to exponentially faster rates of glacial melt and sea level rise. Overall, these findings illustrate the environment’s sensitivity to the emissions that human populations generate, suggesting that given enough pressure, Antarctic ice may enter a runaway downward spiral of rapid melting. 

Please follow, share and like us:
error

Roundup: Video Games, Dust, and Pollinators

Roundup: Jurassic Park, Dust and Interactions

 

Jurassic Park Video Game Features Glacier Park

From Jurassic Wiki: A  Jurassic Park video game features a glacier park located in Patagonia. The game follows similar video games in the genre like Zoo Tycoon where the player designs and monitors a park with formerly extinct animals. Some animals require more upkeep than others and the last thing the owner of the park would want is for them to get out and interact with the customers! “Everybody has been calling this animal the saber-tooth tiger. It does kind of look like a saber-tooth tiger, but it’s actually called the Megistotherium. For this animal, you can take a look at its fossils on Wikipedia,” according to Jurassic Park Builders.

Check out the game here.

A Megistotherium from the Jurassic Park video game (Source: Jurassic Park Wiki).

 

Dust from Asia Reduces Albedo of Glaciers

From Atmospheric Research: “Mineral aerosols scatter and absorb incident solar radiation in the atmosphere, and play an important role in the regional climate of High Mountain Asia (the domain includes the Himalayas, Tibetan Plateau, Pamir, Hindu-kush, Karakorum and Tienshan Mountains). Dust deposition on snow/ice can also change the surface albedo, resulting in [deviations] in the surface radiation balance. However, most studies that have made quantitative assessments of the climatic effect of mineral aerosols over the High Mountain Asia region did not consider the impact of dust on snow/ice at the surface. In this study, a regional climate model coupled with an aerosol–snow/ice feedback module was used to investigate the emission, distribution, and deposition of dust and the climatic effects of aerosols over High Mountain Asia.”

Learn more about dust in High Mountain Asia here.

A glacier in High Mountain Asia (Source: Sandeepachetan.com/Creative Commons).
A glacier in High Mountain Asia (Source: Sandeepachetan.com/Creative Commons).

 

Glacial Retreat Spurs New Interactions

From Anthropod-Plant Interactions: “Successional changes of plant and insect communities have been mainly analysed separately. Therefore, changes in plant–insect interactions along successional gradients on glacier forelands remain unknown, despite their relevance to ecosystem functioning. This study assessed how successional changes of the vegetation influenced the composition of the flower-visiting insect assemblages of two plant species, Leucanthemopsis alpina (L.) Heyw. and Saxifraga bryoides L., selected as the only two insect-pollinated species occurring along the whole succession… We emphasize that dynamics of alpine plant and insect communities may be structured by biotic interactions and feedback processes, rather than only be influenced by harsh abiotic conditions and [randomly determined] events.”

Read more about anthropod-plant interactions here.

An international journal devoted to anthropod-plant interactions (Source: Sitecard).

 

 

 

Please follow, share and like us:
error

“Red snow” algae accelerating glacier melt in the Arctic

Scientists have discovered a troubling new characteristic of the tough algae that grow on the surface of Arctic glaciers: not only do they turn the glacier surfaces red, they accelerate the melting of the ice.

Across the Arctic, from Greenland to Sweden, glacier ice is turning red in what has been termed “watermelon snow.” The phenomenon has become increasingly common in recent years, yet little is known about the algae or their broader environmental impacts.  

"watermelon snow" (wiki)
“watermelon snow” (Source: Will Beback)

A recent study, published June 22 in Nature Communications, has shed light on the red snow, reporting that the algae are contributing to glacier melting and climate change in the Arctic.

The Arctic region covers the majority of the Earth’s northern pole, and contains over 275,500 square kilometers of glaciers. It is also one of the most vulnerable regions to climate change, warming at a rate nearly twice the global average.  According to NASA, the rate of Arctic warming from 1981 to 2001 was a staggering 8 times larger than the rate of melting over the last 100 years. Given the severity of glacier melt in the region, understanding the factors that impact melting rates is crucial to preserving the Arctic ecosystem.

Albedo is one of the most important influences on glacier melt, and the presence of red algae is now speeding up the process. Due to their red pigmentation, algal blooms on ice substantially darken the surface of the glaciers and change their albedo—or the amount of light reflected off of the surface of an object.

Just as black concrete is much hotter to the touch than a pale sidewalk, glaciers covered in red algae absorb more light and melt at a faster rate than clean white ice. This sets off a chain reaction of additional melting, as the meltwater creates a habitat for algae to colonize, and low-albedo rocks and dirty ice underneath glaciers are exposed.

Global albedo showing high reflectivity in the Arctic. Image courtesy Crystal Schaaf, Boston University, based upon data processed by the MODIS Land Science Team
Global albedo showing high reflectivity (red) in the Arctic. Image courtesy Crystal Schaaf, Boston University, based upon data processed by the MODIS Land Science Team

The research team, led by Stefanie Lutz of the University of Leeds, found that the algal blooms are decreasing snow albedo by as much as 13 percent over the course of the melt season in the summer. The phenomenon is widespread.

Forty red snow samples were taken between July 2013 and July 2014 from a total of 16 glaciers in Svalbard, Northern Sweden, Greenland, and Iceland. Results were similar across the board in the different regions. Local ecology, geography, and mineralogy did not have an impact on the ability of the algae to bloom—they are cosmopolitan, able to colonize and spread easily across an ecosystem.

Locations of the 16 glaciers and snow fields across the Arctic, where 40 sites of red snow were sampled (Nature Communications)
Locations of the 16 glaciers and snow fields across the Arctic, where 40 sites of red snow were sampled (Source: Nature Communications)

While the researchers found a rich diversity of bacteria in the glacier samples, the algae did not show the same pattern. Instead, results revealed that the spread of red algae was almost entirely attributable to a small group of algal species–the Chlamydomonadaceae being the most common. Six taxa groups made up over 99 percent of the algae species found in all Arctic locations. These finding set the Arctic apart from other terrestrial ecosystems, which tend to be less homogenous, and indicate that these few species of algae can survive and thrive under a wide range of conditions, and are also likely to spread to other locations.

algal cell (Chlamydomonas nivalis) responsible for red coloration of mountain snow packs (wiki)
algal cell (Chlamydomonas nivalis) responsible for red coloration of mountain snow packs (Source: USDA)

This makes the findings of the study even more pertinent, as red snow will become an increasingly common phenomenon while glacier melt accelerates. According to the study, “Extreme melt events like that in 2012, when 97% of the entire Greenland Ice Sheet was affected by surface melting, are likely to reoccur with increasing frequency in the near future as a consequence of global warming.”
Lutz and the research team conclude that there is a need for this “bio-albedo” effect to be incorporated in future climate models in order to accurately predict the speed and location of glacier melting in the arctic and prepare for the wide range of environmental impacts that will follow.

Please follow, share and like us:
error

Dark Snow Spells Doom for Glacial Melt Rates

lack ash covered the summit of New Zealand’s Mount Ruapehu after an eruption in 2007, but was soon covered by fresh snow. Long-term accumulation of black carbon aerosols in the Arctic and Himalaya is leading to increased melting of snow. (Photo: New Zealand GeoNet)
Black ash covered the summit of New Zealand’s Mount Ruapehu after an eruption in 2007, but was soon covered by fresh snow. Long-term accumulation of black carbon aerosols in the Arctic and Himalaya is leading to increased melting of snow. (Photo: New Zealand GeoNet)

“One week-old snow was turning black and brown before my eyes,” American geologist Ulyana Horodyskyj told the Guardian in earlier this year as she stood at her mini weather station, 5,800 meters above sea level on Mount Himlung, on the Nepal-Tibet border. Horodyskyj studies glaciers in Nepal’s Himalaya mountain range and is one of the many scientists, bloggers, and photographers who are documenting the pernicious effects of a phenomenon called “dark snow.”

This so-called dark snow is being discovered everywhere from the Himalayas to Greenland. Snow can be darkened by naturally made particles, such as soot from wildfires and volcanos or dust from bare soil. But industrial pollution is also a culprit: ultra-fine particles of “black carbon” from industrial plants and diesel engines are often carried in on fierce winds from thousands of miles away. The dust, soot and carbon darken the color of the snow, causing it to absorb more light from the sun, which speeds up glacial melting and lengthens the melt season.

“Governments must act, and people must become more aware of what is happening. It needs to be looked at properly,” said Horodyskyj.

Dark dust deposits on the Yanert ice field and glacier in Alaska. (Ins1122/Flickr)
Dark dust deposits on the Yanert ice field and glacier in Alaska. (Ins1122/Flickr)

In India, about 30 percent of glacial melt is attributed to black carbon, according to the International Centre for Integrated Mountain Development (ICIMOD). In addition, most of the black snow in the Himalayas or the Tibetan Plateau comes from Indian and Chinese soot (e.g. diesel fumes, coal burning, funeral pyres, and etc.). It’s even a problem in the Arctic, according to a paper recently published in Nature Geoscience by a team of meteorologists from the French government. They found that the Arctic ice cap, which is thought to have lost an average of 12.9 billion tonnes of ice a year between 1992 and 2010 due to general warming, may be losing an additional 27 billion tonnes a year due to dust.

This isn’t the first time in the earth’s long history that dust was blamed for glacial melt. Last year, a NASA-led team of scientists published a study in the Proceedings of Natural Academy of Science that found industrial soot led to the retreat of glaciers in the 19th century. The European Alps experienced the abrupt retreat of valley glaciers by about 0.6 miles from 1860 to 1930, during which time the temperature actually dropped continuously. Scientists suspected that the glacier retreats were caused by human activity. After years of research, it turns out that the lower-elevation pollution is a major cause of the mysterious loss of glacier mass.

Darkened ice is found near the edge of Byron Glacier. (Photo: Frank Kovalchek/Flickr)
Darkened ice is found near the edge of Byron Glacier. (Photo: Frank Kovalchek/Flickr)

To better understand and document the dark snow problem, Danish glaciologist Jason Box started the Dark Snow Project around 2 years ago, which measures the impact of changing wildfire soot, industrial black carbons, and snow microbes on snow and ice reflectivity. The Dark Snow Project is currently trying to raise $15,000 for the purchase of three drones to photograph the surface of glaciers in Greenland from a low altitude to examine surface melting.

Please follow, share and like us:
error