New Laser Technology Reveals Climate Change will Induce a Future of Stronger Saharan Dust Storms

In December, an interdisciplinary team of climate scientists, historians, and archaeologists at the University of Maine’s Climate Change Institute and the Initiative for the Science of the Human Past at Harvard published a study in the Journal of Geophysical Research. It detailed how they used a new, high-resolution laser technology to analyze ice from the Colle Gnifetti Glacier on the Swiss-Italian border, and how this technology allowed the team to trace the history of Saharan dust events as well as the atmospheric conditions that promote them. 

Saharan dust covering glaciers. Photo by Margarita Alshina, courtesy of Alex More. 

Saharan dust storms are an influential weather phenomenon for both human and natural systems. Though they fertilize flourishing ecosystems, they can also harm human respiratory health, alter the frequency of North Atlantic hurricanes, and speed the melting of glaciers. Because future occurrences of Saharan dust storms are uncertain given the changing climate, many studies have looked to the past to understand the connection between these dust events and climatic patterns.

Lead author Heather Clifford is a graduate student at the University of Maine Climate Change Institute. She explained that the Saharan dust record held inside the Colle Gnifetti ice core revealed that increased dust transport historically occurs when the atmosphere creates high pressure systems over the Mediterranean and drier conditions over North Africa. Climate change models indicate that these conditions will become more vigorous, indicating a dustier future.

Clifford’s coauthor, Dr. Alex More, is a research professor at the Climate Change Institute at the University of Maine, as well as a researcher at Harvard University and an associate professor in the School of Health Sciences at Long Island University in New York. More explained that in 2012, three of his colleagues (Paul Mayewski (CCI), Michael McCormick (Harvard), and Dietmar Wagenbach (Heidelberg)) wanted to extract an ice core in Europe, instead of the typical polar locations, as the site is closer to impacts from human civilization. Greenland traps signals from a mix of North American regions and Antarctica traps signals from a mix of continents as well –– but the Alps provide a unique look into the history of the Mediterranean region.

Enter the Colle Gnifetti Glacier. “The glacier has been studied for many years because it’s a low accumulation glacier which gives a very clear, particularly high-quality ice for this type of study,” said More. The 72-meter ice core –– the deepest core ever to be dug out of the European Alps –– was extracted in 2013. “This was the first time that researchers from history, climate science, archaeology, volcanology, public health and multiple other disciplines came together for a project like this: from grant-writing to publication,” More said.

The Colle Gnifetti Glacier is located in the NW Swiss-Italian Alps, in the Monte Rosa Mountains. The ice core drilling site is at the foot of the Margherita Hut, the highest building building in Europe at 4554 meters above sea level. Credit: Creative Commons Zero/pxfuel

Clifford took charge of the lab work and data analysis. Normally, ice cores are melted for analysis by a mass spectrometer, the instrument used to determine the elemental signature of a sample. “Imagine spending hundreds of thousands of dollars, sometimes millions, to get tens of meters of ice from the remotest places of the world… and then melting the entire thing.” More added: “We are losing a record of climate change because of climate change, so it’s crazy that we would destroy that ice.” Therefore, the team opted to find a better way to collect their data without melting the ice core.

Clifford’s team is the first to use a non-destructive laser method to sublimate microscopic circles of ice from a core. More explained that the laser moves slowly over the ice inside a vacuum to create a 10-micrometer groove in the core. An argon gas carrier then transfers the sublimated gas from the core to the mass spectrometer where it is analyzed in real time. The core remains intact and the glacier’s record can be preserved forever in a specialized refrigerated depository, even when the actual glacier itself ceases to exist.

While this project is the first to use laser technology for ice core analysis, it has previously been used for lake sediment cores and for archaeological purposes, More explained. Artifacts like ancient coins are precious, and a laser helps determine composition without damaging the structure.

The new laser provides an ultra-high-resolution analysis of glacial ice. More calls it the “gold standard” because it has already produced eight million data points, which is unmatched in their field. “The max data collected for one year is 1,100 data points,” Clifford told GlacierHub. This means they are able reconstruct past atmospheric conditions in much more detail, on subannual to storm-scale event time frames. By contrast, the quality of data obtained by the traditional method of melting ice is coarse and does not provide continuous detail. Using the laser, the researchers created the longest and most accurate record of Saharan dust transport to the European Alps. It spans the past 2,000 years. 

Ice core extraction on the Colle Gnifetti Glacier and the laser ablation method: courtesy of Alex More, Climate Change Institute, University of Maine.

“It took four of us to put the record together and we all lasered over two years,” Clifford said. Lasering was an entirely new methodology that had to be calibrated very carefully, and the laser proceeds slowly, in 100-micrometer increments. “We can only measure the concentration of a few chemical elements at a time, so we often laser the same ice multiple times in order to measure the concentration of different elements. Each element is a piece of the puzzle in understanding climate change, pollution and the human impact on the planet,” More said. 

“A calcium spike alongside an iron spike indicates dust,” said More, referring to the mass spectrometer readings. Then, depending which elements occurred alongside those dust spikes, the researchers could identify how different behaviors in atmospheric circulation deposited the Saharan dust in the Alps.

Some elemental signatures indicated a marine origin. “If they are not present, the air probably took a more direct route across Europe into the Alps,” explained More. Clifford pulled all the elemental data together and found that dust was more likely to be picked up by winds when conditions were dry over the African Sahel, or more arid over the Sahara, or when there was high sea level pressure over the Mediterranean. Periods of drought are expected to become more severe with climate change, so the study predicts an intensification of Saharan dust storms.

Strong Saharan dust storm reaches European Alps, 2003. Credit: NASA (MODIS)

Saharan dust is rich in iron, and when iron mixes with oxygen, it rapidly oxidizes and gives off a distinctive red hue. Dust storms have long been observed by NASA satellites, and was a rare enough phenomenon that they were written about in European historical records, referred to as blood-rain. More, McCormick and their team combed through thousands of historical records to match what they read in the ice with what people wrote about their experiences of these events. This level of detail is only possible thanks to the quality of the laser and historical data combined.

Saharan dust shadow in Greenwich, London, UK. (2014) Credit: Paul Biggs/Flickr 

Saharan dust events in Europe happen 43 times a year on average, on a scale of two to eight days. But More says “these dust storms sometimes occur and people in Europe don’t even notice… They’ll just say ‘oh it’s a hazy day today.’” The study indicates that dust storms are becoming more intense as climate change results in dryer conditions over north Africa. With more drought, stronger winds will have more dust to lift into the atmosphere, carrying more particles to human populations, an intensification already being seen in North Africa.

A NASA article describes how trade winds carry Saharan dust across Western Africa toward the Gulf of Guinea, forming the Harmattan Haze (named after the dusty easterly trade winds) which in Twi means “tears your breath apart.” Susanne Bauer of NASA’s Goddard Institute for Space Studies found that “air pollution in Africa likely caused the premature deaths of about 780,000 people in 2016, more than the number killed by HIV/AIDS,” and 70 percent of these deaths were attributable to dust. “Air pollution is the greatest silent killer,” affirmed More.

Saharan Dust Storm over Western Africa, 2016. Credit: NASA Earth Observatory

In the record, Clifford found that there has already been a significant increase in dust transport over the past century. Climate data show that the conditions she found necessary to fuel dust events will become more severe in the future with climate change. The team predicts that the increase in Saharan dust transfer will worsen air quality and pose a threat to human health, while increased deposits on glaciers will speed up melting and exacerbate the effects of climate change on nature and society.  

Read More on GlacierHub:

Roundup: Bernie Wins First Glacier State Caucus, A Cryosphere Congressional Hearing, and Using Drones to Monitor Ice Flow

Photo Friday: French President Emmanuel Macron Dons Ski Suit and Visits Mont Blanc and Mer de Glace

Congressional Hearing Focuses on Earth’s Changing Cryosphere

Ancient Viruses Awaken as the Tibetan Plateau Melts

Discoveries of microbes locked within the depths of glacial ice are opening an exciting new frontier for scientific research, while also posing an ecological predicament. As climate change causes ice masses to melt worldwide, the re-emergence of ancient bacteria and viruses threatens present day species lacking immunity to these old world pathogens.

Early this year, researcher Zhi-Ping Zhong and a team of researchers discovered 33 viral populations within two ice cores that had been extracted from the Guliya ice cap in the northwestern part of the Tibetan Plateau, in the Kunlun Mountains of northwestern China. The ice dates as far back as 15,000 years ago. All but five of the viral groups are new to science, and about half were predicted to have infected different strains of bacteria, which were also abundant in the ice. 

Researchers trek into the Himalayas to collect ice cores. Credit: Institute of Tibetan Plateau Research, Chinese Academy of Sciences/NASA

The Tibetan Plateau is a vast, high altitude arid grassland home to species like the snow leopard, Tibetan wolf, and wild yak. It is surrounded by some of the world’s highest mountain chains including the Himalayas, the Qilian and Kunlun mountains, and the Karakoram range of northern Kashmir. Shadowed by the world’s two highest peaks, Mount Everest and K2, at an elevation that averages over 4,500 meters, the Tibetan Plateau is known to many as “the roof of the world.” 

To climate scientists, however, the Tibetan Plateau and its crown of peaks is known as “The Third Pole,” since it is home to tens of thousands of glaciers containing the world’s largest non-polar reservoir of ice. These glaciers feed the most renowned Asian rivers, including the Yangtze, Yellow, Mekong, and Ganges which stretch thousands of kilometers into the arid regions of China and Pakistan and supply water to almost a third of the world’s population.

In their paper, which is currently circulating for comment in advance of peer-review, the researchers explain that the shallow plateau core was drilled in 1992 at a depth of 35 meters while the summit core was drilled in 2015 at a depth of 52 meters. The viral populations are quite dissimilar between the two ice cores and are also different at various depths, “presumably representing the very different climate conditions” at the time when the viral particles settled down into the snow to be compacted into ice.

Video from Kevin Bakker: Ice core drilling in Antarctica (circa 2009) for the purposes of studying bacterial community structure.

Though the first reports of microbes being found in glacial ice occurred in the early twentieth century, they were largely neglected until the 1980s when scientists began investigating organisms in an ice core from Vostok, in Eastern Antarctica. This discovery sparked a surge of glacier ice-core sampling at the end of the twentieth century. However, most studies focused on bacterial communities.

Kevin Bakker, an infectious disease modeler at the University of Michigan, studied bacterial community structure in Antarctic water and ice cores in 2008-09. Once his team extracted a core, it was melted down very slowly, “at the room temperature of the icebreaker we were on, so around 40-50 degrees Fahrenheit, to make sure the bacteria were kept alive,” Bakker said in an interview with GlacierHub. “Bacteria pop very easily,” he added, “and we needed them alive to see which organisms were eating the radioactive food we fed them… to see which bacteria were active in the community.” 

But for viruses, the definition of whether they are living or not is a moot point, since the DNA/protein complex (while not technically living) simply takes over its host cell — which most of the time is a bacterium. Zhi-Ping Zhong’s team wrote, “information about viruses in these habitats is still scarce, mainly due to the low biomass of viruses in glacier ice and the lack of a single and universally shared gene for viruses,” which can be used for genome sequencing.

In fact, the authors wrote, “there are only two reports of viruses in glacier ice.” They include the Vostok study, as well as a study that found “tomato-mosaic-tobamovirus RNA in a 140,000-year old Greenland ice core.” Viral genomes from glacier ice have not been previously reported, and “their impacts on ice microbiomes have been unexplored.”

Himalayan glaciers. Credit: NASA Goddard Space Flight Center/Flickr

Moreover, prior to this study, no specific decontamination method existed. In an interview with Vice, Scott O. Rogers, a professor at Bowling Green State University, said “the biomass is so low that anything you contaminate it with on the outside is going to be at much higher concentrations than anything on the inside of the ice core.” Because it is easy to contaminate ancient microbes with modern ones, the researchers developed a new “ultra-clean” method for isolating pure samples from the ice cores. 

The ice cores had been sealed in plastic tubing, covered with aluminum, and transferred at -20 degrees Celsius from the drilling sites to freezers in Lhasa, Beijing, Chicago, and finally to Byrd Polar and Climate Research Center at Ohio State University. In a sub-freezing temperature controlled room, researchers began extracting their samples by first shaving off half a centimeter from the outer contaminated layer of ice. The cores were then washed with ethanol to dissolve another layer, and finally sterile water was used to wash the final half centimeter away.

The pristine inner ice was then methodically melted down and filtered, and steps were taken to identify the virus after extracting the microbial DNA. The virus’s age could be determined by counting the ice layers, just as you would count rings in a tree. To be even more precise, the researchers also dated carbon and oxygen isotopes found in each ice layer.

Layers in an ice core. Credit: Paul Hudson/Flickr

Ancient microbes provide researchers a window into Earth’s evolutionary and climatic past. “We are very far from sampling the entire diversity of viruses on Earth,” Chantal Abergel, an environmental virology researcher at the French National Centre for Scientific Research, told Vice. Unfortunately, glaciers around the world are shrinking at an alarming rate. The Tibetan Plateau itself has lost a quarter of its ice since 1970, so the race is on to collect as much knowledge as possible with what’s left. 

Despite its extreme altitude, the glaciers on the Tibetan Plateau are latitudinally situated to receive a great deal of sunlight, and like the other two, this third pole is warming faster than the global average. In the IPCC special report on the cryosphere, scientists warn that two thirds of its remaining glaciers are bound to disappear by 2100. “This will release glacial microbes and viruses that have been trapped and preserved for tens to hundreds of thousands of years,” wrote Zhi-Ping Zhong’s team.

Tibetan Plateau. Credit: Reurinkjan/Flickr

“At a minimum, this could lead to the loss of microbial and viral archives that could be diagnostic and informative of past Earth climate regimes,” the researchers added. However, “in a worst-case scenario, this ice melt could release pathogens into the environment.” 

This possibility is very real. Bakker pointed out that in 2016, the anthrax virus escaped from a frozen reindeer carcass, killing a 12-year old boy and hospitalizing about twenty others, when permafrost melted in the Siberian tundra. Frozen microbes released through ice melt are still able to reinfect their targets, but while “there are a ton of viruses, only a few actually infect humans,” Bakker explained. Most ancient viruses pose more of a risk to bacteria. Still, it is important not to underestimate the “dangers encased in ice,” Rogers warned in his interview with Vice. 

Zhi-Ping Zhong’s study represents a major advance in the field of virology. It shows how frozen creatures can inform predictions about the types of microbes that may re-emerge with climate warming, and what this could potentially mean for the future of our biosphere. 

Video from Kevin Bakker: Bakker’s research team encounters some friends on their scientific expedition in Antarctica in 2009. Perks of being a scientist!

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Roundup: Sustainable Development, Recovering Glaciers, and Disaster Governance

Global Assesment of Sustainable Mountain Development

From Mountain Research Institute: “The MRI is collaborating with the University of Bern’s Centre for Development and Environment (CDE) to develop an approach for assessing sustainable mountain development using the United Nations Sustainable Development Goals (SDGs) framework. It is expected that this approach will help contextualize and highlight the specific needs and challenges faced in mountain areas, and inform policy and decision-making at all levels…The results of this project will be published as an issue brief in the fourth quarter of 2018. A session dedicated to the presentation of this issue brief will take place at the upcoming World Mountains Forum 2018, to be held in Bishkek, Kyrgyzstan, in October.

Read more about the event here.

Andes Mountains
High mountain ecosystems like the Andes in Peru are extremely vulnerable to climate change (Source: David Stanley/ Creative Commons).

 

Holocene History of the Helheim Glacier

From Quaternary Science Reviews: “Helheim Glacier ranks among the fastest flowing and most ice discharging outlets of the Greenland Ice Sheet (GrIS)… We present the first record of direct Holocene ice-marginal changes of the Helheim Glacier following the initial deglaciation. By analyzing cores from lakes adjacent to the present ice margin, we pinpoint periods of advance and retreat… Helheim Glacier’s present extent is the largest since the last deglaciation, and its Holocene history shows that it is capable of recovering after several millennia of warming and retreat.”

Read more about the research here.

Coring platform and sediment core retrieved from the Niflheim Plateau. A) The inflatable coring platform in use on Lake 297. B) A sediment core (HG309b) retrieved from Lake 309 (Source: Bjork et al.)

 

Impact on Disaster Governance in Ladakh, India

From International Journal of Disaster Risk Reduction: “The Indian border region of Ladakh, in Jammu and Kashmir State, has a sensitive Himalayan ecosystem and has experienced natural hazards and disasters of varying scales over the decades. Ladakh is also situated on a fault-line of multiple tensions, including ongoing border disagreements and intermittent conflict with China and Pakistan. This paper examines the implications of the intersection of these environmental and security factors for disaster governance in the region. This case study provides important insight into why disaster risk reduction has been slow or absent in conflict zones.”

Read more about the research here.

Taglang La mountain pass in Ladakh (Source: Creative Commons).

Photo Friday: Core Of Climate Science

Layer upon layer of snow, built up over thousands of years, ice cores are an archive of Earth’s past. Taken from ice sheets and glaciers, these cores are used for scientific discovery of the climate changes that Earth may have gone through.

This is the focus of Peggy Weil’s “88 cores,” a four-and-a-half hour video descent two miles through the Greenland Ice Sheet in one continuous pan that goes back more than 110,000 years. It aims to explore the intersections of polar ice, time and humanity. “88 cores” is being shown for the first time as the second part of The Climate Museum’s “In Human Time” exhibition from January 19 to February 11.

“The film is not a scientific document, but it is informed by science. Although much of the data gleaned from ice cores is invisible (analysis of gasses, ECM data) the ice itself is visually compelling. The work acknowledges the immensity and grandeur of the ice (and the human effort to understand it) as we contemplate its fragility,” states Weil.

Along with the video, still images of the ice cores will also be on display and accompanied by other artifacts and media that offers context on ice core science and the Arctic.

The exhibition is being presented in partnership with the Parsons School of Design’s Sheila Johnson Design Center at The Arnold and Sheila Aronson Galleries in New York on Fifth Avenue.

For more information on the exhibition and the Climate Museum, visit climatemuseum.org or inhumantime.org

For more information on Peggy Weil, visit pweilstudio.com.

Viewer observing the 88 cores film at 1 meter (Source: Peggy Weil and the US National Ice Core Lab, GISP2).

 

88 cores film test at -1855 meters (Source: Peggy Weil and the US National Ice Core Lab, GISP2).

 

Peggy Weil at the US National Ice Core Lab (Source: Peggy Weil and the US National Ice Core Lab, GISP2).

 

 

Ice core – 2129 meters below the surface (Source: Peggy Weil and the US National Ice Core Lab, GISP2).

 

Tibetan Glacier Reveals History of Pollution

Puruogangri Ice Core Study

A team of scientists led by Emilie Beaudon and Paolo Gabrielli et al. from the Byrd Polar and Climate Center of Ohio State University conducted a study published in Science of the Total Environment presenting a 500-year atmospheric contamination history through the analysis of 28 trace elements from an ice core collected from the Puruogangri glacier in the central Tibetan Plateau. The purpose of the study was, as the authors indicated, “to assess different atmospheric contributions to the ice and provide a temporal perspective on the diverse atmospheric influences over the central Tibetan Plateau.”

The researchers found an overall increasing trend in the levels of trace elements within the ice core from 1497-1992. But what explains the increase of these trace elements in Tibetan glaciers? Was it due to natural or anthropogenic causes?

Atmospheric Dynamics and Tibet

The researchers indicate that the trace element contaminations in the ice core come from two main sources. Prior to 1900, natural causes (such as volcanic fallout) were the primary contributor present in the findings. But with global development of industrial processes in the 19th and 20th century, it became evident to the scientists that post-1900, the main contributors are from anthropogenic sources. The authors argue that the dominant source for the Cd, Zn, Pb, and Ag enrichment increase in the 20th century originates from the metallurgy emission products of former republics within the Soviet Union, particularly Kyrgyzstan and Kazakhstan.

Figure 1. A visual representation of global atmospheric circulation (Source: Creative Commons).

But how would pollutants from Soviet plants reach Tibet? Atmospheric circulation is the key. As Puruograngri lies on the 34th parallel, its position is along the path of the strong mid-latitude westerlies that blow from west to east across the Asian continent as seen on Figure 1 and a NASA GEOS-5 simulation demonstrating the movement of aerosols in atmospheric circulation. As a result, these winds deposit dust and any other particulates in the air on the tall, vast barrier of the Tibetan Plateau.

In addition to Soviet steel production, the authors mention a second proximal source. An increase of Chinese steel production during the Great Leap Forward (1958-1962) corresponds well to the increases in Sb and Pb enrichment in the ice core. But instead of the subtropical westerlies carrying the pollutants, the inconsistent summer monsoonal circulation patterns brought them from the east (China) and south (India and Southeast Asia). As Puruogangri straddles the summer monsoon-dominated south and the year-round dry, westerly-dominated north regions of the Asian continent, it receives influences from both atmospheric patterns depending on the time of year.

But in order to fully understand the significance of the Puruogangri ice core study, a historical perspective is also necessary. With increases in Soviet Union and Chinese steel production identified, it is important to understand the underlying dynamics of steel production in these two countries.

Historical Perspective of the Soviet Union and China

Central Asia was the crossroads of the continent that connected Europe and all parts of Asia with the Silk Road. After the Russian Revolution in 1917, the newly established Soviet Union fully incorporated Central Asia into its domain. As a means of building legitimacy in a new world order post-WWI, the Soviet government sought to transform the previously agricultural country to, as American historian Stephen Kotkin describes, a “country of metal.” A detailed account of the social history surrounding the Soviet industrialization may be found in Kotkin’s book Magnetic Mountain.

China’s Great Leap Forward (1958-1962)(Source: Orient’Adicta/Flickr).

Under the advisement of the Soviet Union, China underwent a similar economic transformation with the rise of the Chinese Communist Party and Mao Zedong in 1949. The study pinpoints the decadal events like the Great Leap Forward (1958-1962) and the Cultural Revolution (1966-1976) as significant periods of industrialization, corresponding to the anthropogenic Sb, Cd, Zn, and Pb levels peaking in 1965. Modern Chinese historian Gina Tam from Trinity University gave GlacierHub a deep-dive into why industrialization was particularly heavy in the 1960s in China.

After falling short of economic goals in the 1950s, Mao instigated a campaign called the Great Leap Forward in hopes to invigorate the economy. “The Great Leap Forward was, above all else, an emphasis on ‘leaping’ forward in terms of economic output. The key targets were steel and grain–the former to make China into a more industrialized country to compete with the West, and the latter to feed all those workers. Given that this was an ‘all hands on deck’ sort of situation, industrialization increased heavily during this time,” Tam told GlacierHub. Devastation followed in terms of mass starvations as well as widespread environmental degradation. Relating this history back to Puruogangri, today’s scientists were able to observe the magnitude of the emission production in both China and the Soviet Union.

What the Records Tells Us

While both of these countries hungrily pursued economic prosperity through metallurgical means, the policies in place put heavy pressure on natural resources and the local environment. The recent Puruogangri study reveals how atmospheric circulation serves as a conveyor belt for anthropogenic pollutants to reach remote glaciers like those in central Tibet.

As the authors noted, “the extraction of multi-century atmospheric pollution records from central Tibet is essential to assess the magnitude of the recent contamination of this remote region and to provide a long-term perspective for the changes observed.” What is particularly noteworthy about this statement is the purpose of scale. While the study assesses patterns across multiple centuries, the authors identify specific decadal events within the 20th century to emphasize a potential shift in the trace element enrichment prior to 1900. Heavy industrialization like during the Great Leap Forward stands out compared to other decades, but based on the results of this study, the researchers ultimately emphasize how the 20th century emission production stands out in comparison to previous centuries.

While scientists like Beaudon and Gabrielli analyze the glacial records for atmospheric contamination input, historians like Koji Hirata from Stanford University are analyzing the written records to trace the levels of steel production output. Despite the tumultuous political atmosphere in both countries throughout the 20th century, historical accounts correspond well with the glacial records. Bridging the understandings between the two disciplines, as well as others, may lead to more informed decision-making on emission controls, ultimately helping to mitigate our changing climate in the uncertain future.

Meltdown in Canadian Ice Core Facility

A view of an ice core in a repository (Source: Fred W. Baker III/USDoD).

The Canadian Ice Core Archive in Edmonton, run by the University of Alberta, recently lost almost 13 percent of their ice cores in a perfect storm of system and equipment failures. The freezer containing thousands of precious ice core samples malfunctioned one weekend in April and the alert that was meant to sound if the freezer failed also faulted. To make matters worse, the system then tried to correct itself, which meant it blew hot air into the room, accelerating the melting of the cores. The temperature in the room rose so high that it set off the fire alarm in the building.

Ice cores at the Canadian Ice Core Archive are typically kept at -37°C. But over the weekend, temperatures increased to upwards of 40°C, leaving inches of water on the floor by Monday morning. In the meltdown, the archive lost some of its oldest and most precious ice cores from Northern Canada that glaciologists have been collecting since the 1970s. In total, 4,000 ice core samples were destroyed overnight, sending ripples of concern through the science community.

The lost ice cores held 22,000 years of data within their layers and came from such diverse locations as Mount Logan, the tallest peak in Canada, and Baffin Island’s Penny Ice Cap, among other locations.

A view of an ice core sample and its layers (Source: Eden, Janine and Jim/Flickr).

It is no surprise that climate scientists and glaciologists value ice core data for what it can tell us about past climate. Glaciers start as layers of snow, which slowly accumulates, forming ice. Dust, pollen, and bubbles of trapped air in each layer of snow becomes a part of the ice. Ice cores are drilled samples of these layers, each sample telling a story of historical atmospheric and temperature conditions. Thus, storage of ice cores in repositories is extremely important.

A scientist preparing and measuring an ice core sample in the field (Source: NASA/Flickr).

Replacing the 4,000 lost ice cores in Edmonton is essentially out of the question. Each sample would cost upwards of $1 million dollars to replace and presents massive logistical issues in obtaining new ones due to the remote location of the Arctic. The process of drilling ice cores is extremely time consuming and technically demanding. Ice cores are either drilled with a thermal or mechanical drill, and samples range from one to six meters in length. 

It seems the only way forward from this ice core catastrophe is to ensure that the Canadian Ice Core Archive does not have another failure. This involves sharing lessons learned from this incident and other ice core repositories.

In times like these, the last thing the world needs is more lost climate data. Fortunately, the archive’s oldest ice from the last continental ice sheet was not in the malfunctioning freezer, a small wrinkle in an otherwise tragic tale.

 

Ice-core Evidence of Copper Smelting 2700 Years Ago

The 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.

Art craft of Moche culture in Lambayeque, PERÚ (source: Douglas Fernandes / Flickr).
Moche mask from Lambayeque, Peru (source: Douglas Fernandes/Flickr).

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.

Location of Illimani (source: Eichler et al.).
Location of Illimani (source: Eichler et al.).

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.

The sculpted head represented the Chavín culture, considered one of the oldest "civilizations" in the Americas [BSO explain this--sculpted head of mythological being at Chavin.](source: Boring Lovechild / Flickr).
A sculpted head at  Chavín de Huantar (source: Boring Lovechild/Flickr).
“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.

Moche copper funeral mask with shell ornaments from Ucupe, Peru (source: University of North Carolina)
Moche copper funeral mask with shell ornaments from Ucupe, Peru (source: University of North Carolina).

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,” Eichler explained. “Furthermore, ancient metallurgical sites are difficult to find because of the lack of substantive remains, particularly smelting installations. Prehistoric smelting furnaces tended to be small or smelting was performed on open fires and thus left little permanent remains.”

Mount Illimani from Aimara, meaning "Golden Eagle" (source: Arturo / Flickr).
Mount Illimani, seen across the Bolivian Altiplano (source: Arturo/Flickr).

The two major sources of copper in the atmosphere— and hence in ice cores from glaciers, where the atmosphere deposits copper compounds— are smelting activities and natural mineral dust. The contribution of Eichler and her team has been to distinguish these and document the creativity of early cultures who developed means to smelt copper.

Pre-industrial Anthropocene Detected in Peru

Humans may have begun to pollute the atmosphere earlier than we thought. So says recent research conducted at the Quelccaya Ice Cap in Peru, where scientists drilled into the ice to pull out cores, which they could read like ancient texts.

QuelccayaThose cores show widespread traces of copper and lead starting in about A.D. 1540, which corresponds to the end of the Inca empire and a period of mining and metallurgy when the areas that are now Peru and Bolivia became part of the Spanish Empire. The findings, published by Paolo Gabrielli and colleagues in February in the Proceedings of the National Academy of Sciences, suggest for the first time that the Anthropocene, the geological epoch defined by massive and widespread human impacts on the planet, began about 240 years before the industrial age arrived on the scene with its steam engines and its coal plants.

Scientists have long used glacier ice cores to learn about the Earth’s climates and air pollution and reconstruct pollution histories. In Greenland, for example, they have traced metals found in ice cores back to ancient Greek and Roman mining operations. The pattern of climate changes and air quality are recorded in the ice itself as glaciers grow, accumulating layer after layer of ice, year after year. For example, winter layers are often thicker and lighter in color, while summer layers are often thinner and darker because of less snowfall and more dust in summer. Scientists can read these layers much in the same way they read tree rings to calculate historical environmental conditions, including snowfall and atmospheric composition.

Layers in Quelccaya ice cap (Source: Emporia State)
Layers in Quelccaya ice cap (Source: Emporia State)

Once the scientists have removed the ice cores from a glacier, they can analyze the trace elements in the ice itself. They also study the air bubbles trapped in those cores at the time of their formation to learn about the chemical components of the atmosphere. According to Paolo Gabrielli, an Earth scientist at Ohio State University, anything in the air at the time the glacier layer was formed, such as soot particles, dust and a wide variety of chemicals, will be trapped in the ice layers as well. Gabrielli says there are no glaciers on Earth in which traces of anthropogenic air pollution cannot be detected.

Gabrielli and his team found that lead levels in the Quelccaya ice core doubled between 1450 and 1900, while the amount of chemical element antimony (Sb) in the ice was 3.5 times greater than  before. They also compared data from a peat bog in Tierra del Fuego, Chile, and from sedimentary lake records from regions including Potosí and other mines throughout Bolivia and Peru to determine the path the pollution took, and found that most of the pollution was carried to the Quelccaya Ice Cap in Peru by the wind.

In the 16th century, the Spanish colonial authorities forced the indigenous populations in South America to extract ore and refine silver from the mountaintop mines of Potosi. They introduced mercury amalgamation, a new technology, to expand silver production, which lead to dramatic increases in the amounts of trace metals released into the atmosphere.

peru2
Silver Mining in South America Source: La Salle University

“This evidence supports the idea that human impact on the environment was widespread even before the industrial revolution,” Gabrielli said in a statement on Ohio State University’s website.

While the industrial economies in 20th century produced more pollution than any other time in human history, colonial mining should be considered the beginning of the Anthropocene, according to these new findings.

For more information about Quelccaya, look here.

Roundup: New Stories on Black Carbon

We feature three stories, all of which focus on black carbon. This atmospheric pollutant plays an important role in accelerating glacier retreat. Moreover, policies can be designed to reduce it, by supporting alternative fuels and improved technologies. Reductions in black carbon also bring health benefits, since this substance leads to pulmonary diseases.

Story 1: Ice Core Data from Svalbard

Flickr/Mariusz Kluzniak
Source: Flickr/Mariusz Kluzniak

“The inner part of a 125 m deep ice core from Holtedahlfonna glacier (79◦8 N, 13◦2 E, 1150 m a.s.l.) was melted, filtered through a quartz fibre filter and analysed for EC using a thermal–optical method. The EC values started to increase after 1850 and peaked around 1910, similar to ice core records from Greenland. Strikingly, the EC values again increase rapidly between 1970 and 2004 after a temporary low point around 1970, reaching unprecedented values in the 1990s. This rise is not seen in Greenland ice cores, and it seems to contradict atmospheric BC measurements indicating generally decreasing atmospheric BC concentrations since 1989 in the Arctic.”

Read more about this research here.

 

Story 2: Black Carbon over the Himalayas and Tibetan Plateau

Source: Flickr/Randomix
Source: Flickr/Randomix

“Black carbon (BC) particles over the Himalayas and Tibetan Plateau (HTP), both airborne and those deposited on snow, have been shown to affect snowmelt and glacier retreat. Since BC over the HTP may originate from a variety of geographical regions 5 and emission sectors, it is essential to quantify the source–receptor relationships of BC in order to understand the contributions of natural and anthropogenic emissions and provide guidance for potential mitigation actions. ”

Read more about this research here.

 

Story 3: Modeling of Climatic and Hydrological Impacts

Source: Flickr/Bernard Blanc
Source: Flickr/Bernard Blanc

“Light absorbing particles (LAP, e.g., black carbon, brown carbon, and dust) influence water and energy budgets of the atmosphere and snowpack in multiple ways. In addition to their effects associated with atmospheric heating by absorption of solar radiation and interactions with clouds, LAP in snow on land and ice can reduce the surface reflectance (a.k.a., surface darkening), which is likely to accelerate the snow aging process and further reduces snow albedo and increases the speed of snowpack melt. LAP in snow and ice (LAPSI) has been identified as one of major forcings affecting climate change, e.g. in the fourth and fifth assessment reports of IPCC. However, the uncertainty level in quantifying this effect remains very high.”

Read more about this research here.