Science

Ice-core Evidence of Copper Smelting 2700 Years Ago

Posted by on Feb 28, 2017 in All Posts, Featured Posts, Science | 0 comments

Ice-core Evidence of Copper Smelting 2700 Years Ago

Spread the News:ShareThe mysterious Moche civilization originated on the northern coast of Peru in 200-800 AD. It was known for its metal work, considered by some to be the most accomplished of any Andean civilization. But were the Moche the first Andean culture to originate copper smelting in South America? While the Moche left comprehensive archaeological evidence of an early sophisticated use of copper, the onset of copper metallurgy is still debated. Some peat-bog records (records of spongy decomposing vegetation) from southern South America demonstrate that copper smelting occurred earlier, around 2000 BC. The question motivated Anja Eichler et al. to launch a massive study of copper emission history. The details of the findings were subsequently published in a paper in Nature. Eichler, an analytical chemistry scientist at the Paul Scherrer Institute in Switzerland, and her team presented a 6500-year copper emission history for the Andean Altiplano based on glacier ice-core records. This is a new methodology applied to trace copper smelting. “Copper is often referred to as the ‘backbone of Andean metallurgy – the mother of all Andean metals,’” Eichler explained to GlacierHub. “However, in contrast to the early copper metallurgy in the Middle East and Europe, very little information existed about its onset in the Andes.” The ice-core they used for their research was drilled at the Illimani Glacier in Bolivia in 1999, nearby sites of the ancient cultures. It provides the first complete history of large-scale copper smelting activities in South America and revealed extensive copper metallurgy. Illimani is the highest mountain in the Cordillera Oriental and the second highest peak in Bolivia. When asked about how she started her research, Eichler told GlacierHub, “I got involved in the project in 2012. At that time, PhD students and a post-doc had already obtained exciting findings and secrets revealed by ice-core records. We started looking at copper and lead as traces from copper and silver mining and smelting in the Andes.” The results of Eichler et al.’s study suggest that the earliest anthropogenic copper pollution occurred between 700–50 BC, during the central Andean Chiripa and Chavin cultures, around 2700 years ago, meaning that copper was produced extensively much earlier than people originally thought. “For the first time, our study provides substantial evidence for extensive copper metallurgy already during these early cultures,” said Eichler. One of the most challenging parts of the research is that copper can show up in the ice core from natural as well as human sources. Eichler’s team accounted for this by calculating the copper Enrichment Factor, which is applied widely to distinguish the natural and anthropogenic origin of metal. The principle of this methodology is to measure the occurrence of different metals. If copper appeared naturally due to wind erosion, it would be found in association with other metals that co-occur with it naturally. However, according to Eichler’s findings, there was only copper in central Andean Chiripa and Chavin cultures, without cerium or the other metals that occur with it in natural deposits. Hence, it was anthropogenic. The Chiripa culture existed from 1400 BC to 850 BC along the southern shore of Lake Titicaca in Bolivia,  near Illimani Glacier. Soon after the Chiripa, came the Chavin culture, a prehistoric civilization that developed in the northern Andean highlands of Peru from 900 BC to 200 BC, named for Chavín de Huantar, the principal archaeological site where their artifacts have been found. Copper objects from these earlier cultures are scanty. The reason why there is no sufficient archaeological evidence of copper usage, according to Eichler, is that very often artifacts were reused by subsequent cultures. “It is known that metallic objects cast by civilizations were typically scavenged from artifacts of their predecessors,”...

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Rock Glaciers Help Protect Species in a Warmer Climate

Posted by on Feb 22, 2017 in Adaptation, Featured Posts, Images, Interviews, Science | 0 comments

Rock Glaciers Help Protect Species in a Warmer Climate

Spread the News:ShareIn a recent study by Duccio Tampucci et al., rock glaciers in the Italian Alps have been shown to host a wide variety of flora and fauna, supporting plant and arthropod species during temporary decadal periods of climatic warming. Certain species that thrive in cold conditions have been prone to high environmental stress during warm climate stages in the past, but given the results of Tampucci’s research, it is now clear that these species may be able to survive in periglacial settings on the edge of existing glaciers. Active rock glaciers, commonly found on the border of larger glaciers and ice sheets, are comprised of coarse debris with intermixed ice or an ice-core. The study has valuable implications on how organisms may respond to changes in temperature, offering a possible explanation for species’ resiliency. Jonathan Anderson, a retired Glacier National Park ranger, spoke to GlacierHub about the importance of periglacial realms in providing a habitat for animals displaced by modern climate change. “In the years spent in and around the park, it’s clear that more and more animals are feeling the impact of climate change and global warming,” he said. “The areas surrounding the larger glaciers are becoming even more important than before and are now home to many of the species that lived on the receded glacier.” In their study, Tampucci and team analyzed abiotic dimensions of active rock glaciers such as ground surface temperature, humidity and soil chemistry, as well as biotic factors related to the species abundance of plants and arthropods. This data was then compared to surrounding iceless regions characterized by large scree slopes (small loose stones covering mountain slopes) as an experimental control for the glaciated landforms of interest. Comparisons between these active scree slopes and rock glaciers revealed similar soil geochemistry, yet colder ground surface temperatures existed on the rocky glaciers. Thus, more cold-adapted species existed on rock glaciers. The distribution of plant and arthropod species was found to be highly variable, dependent upon soil pH and the severity of mountain slope-instability. This variability is because the fraction of coarse debris and quantity of organic matter changes with the landform’s activity, or amount of mass wasting occurring downslope. The study notes that the heterogeneity in landforms in mountainous regions augments the overall biodiversity of the region. Anderson affirmed this idea, noting, “The difference in habitats between glaciated terrain and the surrounding, more vegetated regions is crucial for allowing a wide range of animals to coexist.” This variety of landforms contributes to a wide variety of microclimates in which ecologically diverse organisms can reside in close proximity. Cold-adapted species are likely the first to be affected by region-wide seasonal warming. As temperatures increase, cold-weather habitats are liable to reduce in size and shift to higher altitudinal belts, resulting in species reduction and possible extirpation. Tampucci et al.’s study affirmed the notion that active rock glaciers serve as refugia for cold-adapted species due to the landscape’s microclimate features. The local periglacial environment in the Italian Ortles-Cevedale Massif, for example, was shown to be decoupled from greater regional climate, with sufficient thermal inertia (resistance to temperature change) to support cold-adapted species on a decadal timescale. Despite the conclusive findings that largely affirm previous assumptions about biodiversity in active rock glaciers, the authors carefully point out that the glacier’s ability to serve as refugia for certain species depends entirely on the length of the warm-climate stage, which can potentially last for millennia. Additionally, the macroclimatic context in which the glaciers reside is important and can influence the landform’s thermal inertia, affecting the temporal scale at...

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Research Shows How Climate Change Drives Glacier Retreat

Posted by on Feb 21, 2017 in All Posts, Featured Posts, Science | 0 comments

Research Shows How Climate Change Drives Glacier Retreat

Spread the News:ShareShrinking glaciers are oft-cited examples of the effects of anthropogenic climate change, providing dramatic imagery in different parts of the world. However, this has mostly been based on global aggregates of glacier extent. Differing opinions also exist about the best way to measure glacial change all over the world.  A recent study by Roe et al., published in Nature Geoscience, confirms that climate change has contributed to the shortening of numerous glaciers around the world, but the study is not immune to controversy surroundings the methods used. Using a combination of meteorological data and observations of glacier length, Roe et al. studied the influence of climate on 37 glaciers between 1880 and 2010. The glaciers were selected based on the continuity of length observations and the need for a wide geographical distribution. Glacier mass-balance records are a more direct measure of the effect of climate than glacier length as they measure the difference between the accumulation and ablation (sublimation or melting) of glacier ice. However, most mass-balance records do not extend for more than two decades, contributing to the previous lack of confirmation of the effect of climate change on individual glaciers around the world. The use of observations of glacier length helped to overcome this obstacle, but challenges were still encountered in obtaining long, continuous data sets, particularly for regions such as Asia and South America. In conversation with GlacierHub, Roe shared that many factors can affect the availability of continuous data sets. “For example, the collapse of the Soviet Union led to many glacier observation programs being abandoned,” he stated. An additional challenge arose from the variation in conditions experienced by each glacier. “Every glacier is a unique product of its local climate and landscape,” Roe shared, citing the example of maritime glaciers, which typically experience a large degree of wintertime accumulation variability. “This can mask the signal of a warming that, so far, has mainly impacted the summertime mass balance,” he added. Nevertheless, Roe et al. found that there was at least a 99% chance that a change in climate was needed to account for the retreat of 21 of the glaciers studied. “Even for the least statistically significant (Rabots Glacier in Sweden), there was still an 89% chance that its retreat required a climate change,” Roe said. As glaciers tend to have decadal responses to changes in climate, their retreat since 1880 is likely to be a result of twentieth-century temperature trends. They also act as amplifiers of local climate trends, providing strong signal-to-noise ratios that serve as strong evidence for the effects of anthropogenic climate change. For example, one of the glaciers included in the study, Hintereisferner in the Austrian Alps, retreated 2,800m since 1880, with a standard deviation (a measure of the deviation of values from the mean) of 130m. This value is small compared to the amount of retreat, providing a strong signal of change. “We hope that these results will lead to a stronger scientific consensus about the cause of glacier retreat. The last round of the Intergovernmental Panel on Climate Change was quite timid, concluding only that it was ‘likely’ that a ‘substantial’ part of glacier retreat was due to human-caused climate change,” Roe added. IPCC nomenclature would make it “very likely” (≥90%) that all but one of the glaciers in this study have retreated because of climate change, allowing for stronger conclusions to be drawn. Excitement about the results of this study was shared by Joerg Schaefer, professor at the Lamont-Doherty Earth Observatory: “Under Roe’s lead, the really smart glacier people find ways to explain this strange...

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Roundup: Snow Bacteria, Sting, and Glacier Awareness

Posted by on Feb 20, 2017 in All Posts, Featured Posts, News, Roundup, Science | 0 comments

Roundup: Snow Bacteria, Sting, and Glacier Awareness

Spread the News:ShareRoundup: Bacteria, Sting, and Glacier Awareness   Snow Bacteria in the Tibetan Plateau From INFONA: “Snow bacterial abundance and diversity at the Guoqu Glacier and the East Rongbuk Glacier located in the central and southern Tibetan Plateau were investigated using a 16S rRNA gene clone library and flow cytometry approach. Bacterial abundance was observed to show seasonal variation, with different patterns, at the two glaciers. High bacterial abundance occurs during the monsoon season at the East Rongbuk Glacier and during the non-monsoon season at the Guoqu Glacier. Seasonal variation in abundance is caused by the snow bacterial growth at the East Rongbuk Glacier, but by bacterial input from the dust at the Guoqu Glacier. Under the influence of various atmospheric circulations and temperature, bacterial diversity varies seasonally at different degrees.” Read more about it here.     New Animated Music Video – Sting’s “One Fine Day” From AboutVideo: “Some celebrities do not grow old, not only outwardly but also in the creative plan. In November 2016, the British singer Sting has pleased his fans with a new studio album ’57th & 9th,’ his 12th. On sounding, the album refers to the days Sting was part of the band The Police. The success of the new album has fixed the singer in the top twenty of the UK Albums Charts… In the song ‘One Fine Day,’ Sting sings about protecting the environment. He calls for common sense with regard to nature and its gifts. The musician appears in the video as a silhouette on crumpled paper. The beautiful images on paper give a sense of danger. Sting shows how the glaciers are melting and the politicians are endlessly arguing with each other, leading to the destruction of the planet.” Watch the video here.     Raising Awareness About Glacier Retreat From Pamir Times: “A group of mountaineers and a researcher from Shimshal Valley – Hunza, reached Askoli, a remote mountain village in Skardu, after walking across the Braldu Pass. They are on a a mission to raise awareness about saving glaciers from depleting… The expedition members surveyed Mulungdi glacier and Khurdupin glacier before embarking on their journey to Askoli on January 6… Pakistan is home to world’s largest ice glaciers out of the polar region. Spread over an area of 16933 square kilometers, there are over 5000 glaciers in the Gilgit-Baltistan and Chitral regions of Pakistan, including the famous Siachin Glacier, Biafo Glacier, Khoordhopin Glacier, Batura Glacier, Braldu Glacier, Snow lake and many more. These glaciers are the major source of water feeding the major rivers in Pakistan.” Learn more here.   Spread the...

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Brittle Stars, Sea Urchins, and Starfish

Posted by on Feb 16, 2017 in All Posts, Featured Posts, Science | 0 comments

Brittle Stars, Sea Urchins, and Starfish

Spread the News:ShareThe increase of heat-trapping greenhouse gases in Earth’s atmosphere is warming the Antarctic Peninsula at a unprecedented rate. A recent study from Angulo-Preckler et al. in Continental Shelf Research explores whether significant decreases in sea ice and melting glaciers in the waters west of the Antarctic Peninsula favor some species of marine life and harm others. Among the species which call the waters home, the authors of this study focus on echinoderms, an invertebrate phylum that includes starfish, sea urchins and brittle stars. Accounting for approximately 45 percent of biomass on the ocean floor west of the Antarctic Peninsula, echinoderms live between the intertidal zone and the sea floor. With no heart, brain or eyes, echinoderms use tentacle-like structures with attached suction pads on their appendages to slowly traverse underwater surfaces. As filter-feeders, echinoderms grab their prey with tentacles, consuming it through a mouth located on their underside. Although echinoderms already live in an environmentally challenging location, with water temperatures reaching 0°C and below, melting glaciers are adding an additional level of complexity to their ecosystem. For example, on Deception Island, a volcanically-active island in the South Shetland Islands archipelago, physical disturbance from the volcano and glacier retreat are causing alterations to the ecosystem. Deception Island’s volcano last erupted in 1970, yet volcanic ash from that eruption and previous eruptions settled on nearby glaciers. As the glaciers melt, volcanic ash travels from glacial surfaces to the marine waters below. In turn, mixing marine waters distribute volcanic ash to depths where echinoderms dwell in a process called sedimentation. This impacts the survival of some echinoderms as they are incapable of thriving under high levels of sedimentation. High sedimentation is problematic for certain species because the additional material prevents them from easily inhabiting crevices between rocks and sponges. Port Foster, a bay encompassed by Deception Island, is fed by the surrounding melting glaciers. Angulo-Preckler et al. examined eight different locations in the Deception Island bay, at both 5 meters and 15 meters, to determine a relationship between high sedimentation rates and the number of echinoderms. The study found three dominant echinoderms – the brittle star (Ophionotus victoriae), the Antarctic sea urchin (Sterechinus neumayeri) and the Southern Ocean starfish (Odontaster validus) – are coping well to the high sedimentation rates, at the expense of other echinoderms. The researchers found that the opportunistic brittle star and sea urchin are now dominating areas of Deception Island Bay by replacing other echinoderms, such as the sea cucumber. Where there was once a large variety of species, there are now just three main echinoderms. This reduction in biodiversity has implications for the health of the ecosystem. High ash sedimentation from the volcano and high sedimentation rates due to the retreat of glaciers could decrease biodiversity levels at Port Foster by forcing other species out of their habitat. Since the last eruption, many of the echinoderms that once flourished in the area have now disappeared. As the region continues to warm, research suggests that increasing sedimentation from melting glaciers could continue to impact the communities of the intertidal and benthic zone of western Antarctica. Ricardo Sahade, an Antarctic ecologist from the National University of Córdoba in Argentina, confirmed to GlacierHub that “coastal ecosystems experiencing glacier retreat can be threatened by increased sedimentation.” More sedimentation and melting glaciers change the composition of echinoderm habitat. Further research will provide fuller details on whether higher sedimentation reduces biodiversity in this marine ecosystem. Even now, it is evident that disturbances from retreating glaciers are changing the Antarctic ecosystem and the habitat it provides. Spread the...

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When Lava Hits Ice in Russia’s Far East

Posted by on Feb 15, 2017 in All Posts, Featured Posts, News, Science | 0 comments

When Lava Hits Ice in Russia’s Far East

Spread the News:ShareThe Kamchatka Peninsula in Far East Russia is an isolated region known for its glacier-volcano interactions that can lead to powerful natural disasters— and also, visually stunning images when lava impacts ice. One of these volcanoes, Sheveluch, has been erupting in recent weeks, creating local hazards. The volcano’s ash cloud, for one, threatens to disrupt air traffic in the region. In total, Kamchatka is home to 160 volcanoes, 29 of which are currently active. These volcanoes— six of which are designated UNESCO World Heritage sites— are tall and far enough north to harbor glaciers. As such, they are associated with lahars, devastating mudslides down the slopes of a volcano triggered by an eruption and melting glaciers. These mudslides move quickly, destroying most of the structures in their path. Explosive-effusive #eruption of 2016 (April to October)#volcano #Klyuchevskoy 08/21/2016Photo: Vladimir Voychuk pic.twitter.com/5wOhpyVg1s — Войчук Владимир (@voy4uk) January 26, 2017 Avachinsky is one active volcano in the region that is covered in glaciers, placing the surrounding region at a greater risk for lahars. Avachinsky is classified as a stratovolcano, which is a volcano that has been built up by alternate layers of lava and ash. It is the volcano closest to the state capital Petropavlovsk-Kamchatsky.  “The Avachinsky volcano is glacierized, and the melting of ice poses a serious lahar threat the next time the volcano is active,” Ben Edwards, a volcanologist and professor at Dickinson College, warns. Edwards explained to GlacierHub that there are many deposits mapped out that are indicative of past lahars. Previous lahars in the Kamchatka Peninsula have been devastating with high human death tolls. The Nevado del Ruiz volcano in Colombia, for example, erupted in 1985, producing a lahar that killed 23,000 people. “They are incredible forces of nature and also brutally destructive and deadly,” said Janine Krippner, a PhD candidate in volcanology and remote sensing at the University of Pittsburgh, in an interview with GlacierHub. The Klyuchevskaya Sopka stratovolcano is the highest mountain on the peninsula and the highest active volcano in Eurasia. In November 2016 and more recently in January, the volcano spewed ash six kilometers above sea level. Such an ash cloud can disrupt international travel. Klyuchevskaya has produced notable lahars in the past including one particularly damaging one in 1993, according to Edwards. The position of a glacier on a volcano can influence the risk of a lahar.  However, there is still much research needed on past lahars at Klyuchevskaya to better understand risk, notes Edwards. “Many volcanoes have glaciers up high, but those close to Klyuchevskaya are on the western lower flank,” explained Edwards. “There have probably been some interactions and definitely lahars generated from historic flows. But these eruptions have not been well documented.” Higher regions, which tend to be cooler and moister, are more likely to form glaciers. Sheveluch Peak is a very active volcano, and the largest on the peninsula at 1,300 cubic kilometers in volume. Many glacier-volcano interactions have occurred at the location, releasing great quantities of steam and creating fantastic imagery for photographers. Similar volcano-snow interactions also take place elsewhere on the peninsula, especially during the winter, according to Edwards. “We saw spectacular examples during the 2012-13 Tolbachik eruption,” he said. The World Heritage website, which features several of the Kamchatka Peninsula volcanoes, makes special note of the “dynamic landscape of great beauty” created by the interplay of active volcanoes and glacier forms. In addition, the peninsula has a wide diversity of species including brown bears, sea otters and the world’s largest variety of salmon fish. It is also known for a wide variety of birds from falcons to eagles that are attracted to the...

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