Glacier Retreat and Trace-Metal Contamination in Peru

The Cordillera Blanca, the largest glacial area in the tropics (Source: Richard Doker/Flickr).

The Cordillera Blanca is the most glacierized area in the tropics, but in the last 30 years the region has lost over 25 percent of its glacier area. A consequence of this glacier retreat has been higher concentrations of heavy metals downstream, which have created serious water contamination issues for indigenous communities living nearby the shrinking glaciers. A recent study led by Alexandre Guittard, Michel Baraër, Jeffrey M. McKenzie and others provided a comprehensive assessment of the extent of trace-metal contamination across the Rio Santa basin, one of the largest and most important rivers in the Cordillera Blanca range.

Part of the glacier runoff from the Cordillera Blanca that feeds the Rio Santa (Source: Esmée Winnubst/Flickr).

About 300 miles northeast of the capital city of Lima, the glacier-fed Santa river is located in the Ancash Region of Peru, flowing north between the glacierized Blanca and the non-glacierized Negra mountain ranges, winding west through the Cañon del Pato before discharging into the Pacific Ocean. Since the 1940s, the region has experienced population growth and increased economic activities, greatly intensifying water demand.

“For two decades we have been hearing about shrinking mountain glaciers and the impacts on downstream water supplies. But the vast majority of the research in glacierized basins so far has been on the quantity of water coming out of the glaciers, not the quality of that water,” environmental historian Mark Carey, one of the authors of the study, explained to GlacierHub. “Studies must also take seriously the issues of intensifying water contamination and risk levels for communities living downstream from shrinking glaciers.”

But how does glacier retreat result in trace metal contamination? Essentially, there are two opposing theories, according to lead author Michel Baraër. The first theory is that glacier retreat uncovers bedrock rich in pyrite that oxidizes when uncovered, acidifying the water and facilitating the release of trace metals in water, he told GlacierHub.

The second theory deals with glacier retreat and its impact on the physical weathering of the bedrock, which decreases in intensity. “There are therefore less fresh particles released in water bodies and therefore less trace metals,” he said. To break down the two theories, the authors pinpoint anthropogenic sources (i.e. active mining) to be a major source of the trace metal contamination. Thus, even if the two theories counteract one another, scientists consider the anthropogenic influence of industrial mining, as noted throughout the study, to be a much stronger contributor to the water contamination.

This map demonstrates the breakdown of trace-metal contamination across the Rio Santa Basin (Source: Guittard et al.).

According to the study, “the findings indicate that contamination levels in some areas of the watershed could potentially represent a threat to the health of humans or ecosystems.” Water quality has been a major issue in recent years, and the contamination of arsenic and manganese as found could have devastating health and ecological impacts on the quality of life in the Rio Santa basin.

Even if mining activities are shut down, contamination would continue to be problematic under climate change if the first theory— that glacier retreat exacerbates the oxidation process— outweighs the second that states it slows the release. There is already concern about another health risk: disease-causing organisms that may be lying dormant in ice. They might become more active as they thaw. If that is the case, communities and scientists must keep a careful eye on receding glaciers across the world to see what health impacts may arise when the ice melts.

Roundup: Climate justice, Impacts of Glacial Retreat, and Sediments

German Court to Hear Peruvian Farmer’s Climate Case Against RWE

From The Guardian: “A German court has ruled that it will hear a Peruvian farmer’s case against energy giant RWE over climate change damage in the Andes, a decision labeled by campaigners as a ‘historic breakthrough.’ Farmer Saul Luciano Lliuya’s case against RWE was ‘well-founded,’ the court in the north-western city of Hamm said on Thursday. Lliuya argues that RWE, as one of the world’s top emitters of climate-altering carbon dioxide, must share in the cost of protecting his hometown Huaraz from a swollen glacier lake at risk of overflowing from melting snow and ice.”

Read the full report here.

Saul Luciano Lliuya, a farmer from Peru, at the UN climate talks in Bonn earlier this month. (Source: The Guardian/Twitter).

 

Impacts of Rapidly Declining Snow and Ice in the Tropical Andes

From ScienceDirect: “The reduction in water supply for export-oriented agriculture, mining, hydropower production and human consumption are the most commonly discussed concerns associated with glacier retreat, but many other aspects including glacial hazards, tourism and recreation, and ecosystem integrity are also affected by glacier retreat. Social and political problems surrounding water allocation for subsistence farming have led to conflicts due to lack of adequate water governance. This review elaborates on the need for adaptation as well as the challenges and constraints many adaptation projects are faced with, and lays out future directions where opportunities exist to develop successful, culturally acceptable and sustainable adaptation strategies.

Read the research paper here.

Declining glacier on Mt. Ausangate in the Peruvian Andes (Source: Wikimedia Commons).

 

Greenland’s Meltwaters

From Nature Geoscience: “Limited measurements along Greenland’s remote coastline hamper quantification of the sediment and associated nutrients draining the Greenland ice sheet, despite the potential influence of river-transported suspended sediment on phytoplankton blooms and carbon sequestration. We find that, although runoff from Greenland represents only 1.1 percent of the Earth’s freshwater flux, the Greenland ice sheet produces approximately 8 percent of the modern fluvial export of suspended sediment to the global ocean. We conclude that future acceleration of melt and ice sheet flow may increase sediment delivery from Greenland to its fjords and the nearby ocean. ”

Read more here.

Researchers collecting samples of subglacial discharge from a land-terminating glacier of the Greenland ice sheet (Source: I. Overeem et al/Nature.com).

 

Wildfires in Peru Could Increase Glacial Melt

A recent study by John All et al., “Fire Response to Local Climate Variability,” investigates whether or not human interference in the fire regime of Huascarán National Park in Peru was the primary cause of an increase in fire activity in the park. The fire activity, whether caused by humans or climate variability, was poorly understood because of a lack of historical data. The wildfires in this park are continuing to grow and could pose a threat to surrounding glaciers. Resource managers believed that the fire increase was human-caused and not necessarily linked to climate processes, but in this instance, fire perception and fire reality are not aligning. The new challenge for resource managers is how best to reconcile these two factors to more effectively manage the parklands. If the wildfires become more frequent, the glaciers in Huascarán National Park could melt at faster rates because of the soot and other material from the fires deposited on them.

The 3,400 km Huascarán National Park is located in the Cordillera Blanca range in north-central Peru, the largest glaciated area in the tropics, with 80 glaciers and 120 glacial lakes. The park, created in 1975 and named a UNESCO World Heritage site in 1985, has already seen a significant loss of ice and snow in the region in the past 60 years, according to research published in the journal Mountain Research and Development, altering the glacier melt that supplies water for the Santa, Marañón, and Pativilca River basins.

A fire destroyed 2,000 acres in Huascaran National Park in 2012 (Source: River of Life/Creative Commons).

The study’s goal was to help the park’s land managers understand the patterns of the fires, why they’ve been changing, and how to better manage the park in the future. When asked if climate change could make the wildfires more frequent, Edson Ramírez Henostroza, a security specialist for rescue and fire control at Huascarán National Park, told GlacierHub, “Yes, in our country, there is the popular belief that fire and smoke generate rain, and that ash balances the pH of the soil, which is usually acid in the Andes, causing the peasants to burn more pastures ad bushes in search of rain and more productive soils.”

From 2002 to 2014, Huascarán National Park has seen higher activity of grazing and anthropogenic burning, due to natural ignitions and climate variability, which has altered the regimes and population dynamics of the vegetative communities. Anthropogenic fires are usually caused by livestock owners who start fires to get rid of biomass and improve grass regrowth for the next grazing season. Humans change the characteristics of fires, such as the intensity, severity, number, and spread. “We believe that the best tools to prevent forest fires is environmental education, to reach schools in rural areas and talk to peasants and their children,” Edson told GlacierHub.

Huascaran Park Glaciers (Source: Sergejf/Flickr).

Since the 1970’s, glaciers in the tropical Andes have receded at a rate of 30 percent. Increased black carbon and dust will only quicken this glacial recession. A consequence of man-made fires is the release of black carbona particulate matter released by the combustion of fossil fuels, biofuel and biomass, which accelerates glacial melt when deposited on glaciers. Since black carbon absorbs solar energy, it has the ability to warm the atmosphere and speed up the melting process on glaciers.

In an interview with GlacierHub, John All, a research professor in the Department of Environmental Science at Huxley College and one of the co-authors of the study, said, “There are multiple potential sources of black carbon, but our work indicates that black carbon on glaciers in the Cordillera Blanca is almost entirely ‘young’ carbon – i.e. not fossil carbon like diesel. Mountain fires potentially provide large amounts and large particle sizes of local black carbon that can be deposited immediately onto the glacier.”

Lake 69 in Cordillera Blanca, Huaraz, Peru (Source: Arnaud_Z_Voyage/Flickr).

Park managers are working to save the park from future fire-related accidents by bringing on specialists like John All. “We began this research at the request of the Park Superintendent because he was concerned about how these fires, which are ignited to improve grazing in the Park, were affecting the ecosystem and visitor experiences,” he told GlacierHub. “We’ve worked with USAID and various Peruvian agencies to hold workshops and work with local stakeholders to curb burning practices. However, as natural fire conditions become more explosive, even accidental fires may become widespread in the future.” More research needs to be done in order to improve fire management and learn more about the fires’ impact on the park.

Roundup: Seals, Flood Mitigation, and Freezing Levels

Seal Whiskers Detect Ecosystem Change

From Polar Biology: “Warm Atlantic water in west Spitsbergen have led to an influx of more fish species. The most abundant marine mammal species in these fjords is the ringed seal. In this study, we used isotopic data from whiskers of two cohorts of adult ringed seals to determine whether signals of ecosystem changes were detectable in this top marine predator.”

Find out more about ringed seals here.

A ringed seal in Kongsfjorden, North West Spitsbergen (Source: The Might Fine Company/Google Images).

 

Flood Mitigation Strategies in Pakistan

From Natural Hazards: “The frequency and severity of flood events have been increased and have affected the livelihood and well-being of millions of people in Pakistan. Effective mitigation policies require an understanding of the impacts and local responses to extreme events, which is limited in Pakistan. This study revealed the adaptation measures adopted in Pakistan, and that the local policies on disaster management need to be improved to address the barriers to the adoption of advanced level adaptation measures.”

Find out more about flood risk mitigation in Pakistan here.

Pakistani villagers leaving their homes after a flood in Muridke (Source: DAWN/Google Images).

 

Rising Freezing Levels in Tropical Andes

From AGU Publications: “The mass balance of tropical glaciers in Peru is highly sensitive to a rise in the freezing level height (FLH). Knowledge of future changes in the FLH is crucial to estimating changes in glacier extents. Glaciers may continue shrinking considerably, and the consequences of vanishing glaciers are especially severe where people have only limited capacity to adapt to changes in the water availability due to, for instance, lack of financial resources.”

Find out more about freezing levels in Peru here.

Evidence of melting at Pastoruri glacier in Northern Peru (Source: Inyucho/Creative Commons).

 

Roundup: Avalanches, Droughts, and a Sherpa protest

Roundup: Avalanches, Droughts, and Sherpas

 

Calving Event in Peruvian Lake Damages Infrastructure Designed to Reduce Flood Risk

From El Comercio: “Small ice avalanches have damaged the system of syphons in Lake Palcacocha, Ancash, Peru. Marco Zapata, the head of the Glacier Research Unit at INAIGEM, stated that on May 31, around 8 p.m., a calving event occurred at the glacier front on Mount Pucaranra, releasing ice into the lake. This event generated waves 3 meters in height, which caused 10 of the syphons to shift and which destroyed three gauges and a water level sensor.”

Find out more about Lake Palcacocha and ice avalanches here.

Locals treating the material that was shifted due to the ice avalanches (Source: INDECI).

 

Asian Glaciers Fight Against Drought

From Nature: “The high mountains of Asia… have the highest concentration of glaciers globally, and 800 million people depend in part on meltwater from them. Water stress makes this region vulnerable economically and socially to drought, but glaciers are a uniquely drought-resilient source of water. Glaciers provide summer meltwater to rivers and aquifers that is sufficient for the basic needs of 136 million people… Predicted glacier loss would add considerably to drought-related water stress. Such additional water stress increases the risk of social instability, conflict and sudden, uncontrolled population migrations triggered by water scarcity, which is already associated with the large and rapidly growing populations and hydro-economies of these basins.”

Find out more about Asia’s drought-resilient glaciers here.

Central Asia’s glaciers may lose half their ice by mid-century (Source: Twiga269/Flickr).

 

Sherpas Demand Summit Certificates at Protest

From The Himalayan Times: “Hundreds of sherpa climbers who met at Mt Everest base camp [in May] asked the government to immediately issue their summit certificates… Sherpa climbers who made it to the top of several peaks, including Mt Everest, have not been getting their summit certificates since last year after the government refused to approve their ascents citing a clause of the Mountaineering Expedition Regulation that bars them from obtaining such certificates… For most of the foreign climbers, summiting a mountain without sherpas’ help is almost impossible in Nepal… The new amendment to the regulation will recognize high-altitude workers as a part of the expedition to get certificates.”

Find out more about the Sherpa protest and resolution here.

Members of the Sherpa community have recently protested to demand summit permits (Source: Pavel Matejicek/Flickr).

 

 

Using Drones to Study Glaciers

Understanding the nature of glacial changes has become increasingly important as anthropogenic climate change alters their pace and extent. A new study published in The Cryosphere Discussions journal shows how Unmanned Aerial Vehicles (UAVs), commonly known as drones, can be used to do this in a relatively cheap, safe and accurate way. The study represents the first time a drone has been used to study a high-altitude tropical Andean glacier, offering insight into melt rates and glacial lake outburst flood (GLOF) hazards in Peru.

The researchers used a custom-built drone (Source: Oliver Wigmore).

The study was carried out by Oliver Wigmore and Bryan Mark, from the University of Colorado Boulder and Ohio State University respectively. It is part of a larger project aimed at understanding how climate change is affecting the hydrology of the region and how locals are adapting to these changes.

The researchers used a custom-built hexa-multirotor drone (a drone with propellers on six arms) that weighed about 2kg to study changes in Llaca Glacier in the central Cordillera Blanca of the Peruvian Andes.

Llaca, one of more than 700 glaciers in the Cordillera Blanca, was chosen for both logistical and scientific reasons. It covers an area of about 4.68 square kilometers in Huascaran National Park and spans an altitudinal range of about 6000 to 4500 meters above sea level. Like other glaciers within the Cordillera Blanca, it has been retreating rapidly because of anthropogenic climate change.

The researchers hiked to the glacier to conduct surveys (Source: Oliver Wigmore).

To obtain footage, the researchers had to drive three hours on a winding, bumpy road from the nearest town, located about 10km away from the valley. “This was followed by a halfhour hike to the glacier,” Wigmore stated.

To overcome some of the challenges of working in a remote, high-altitude region, the drone was custom-built using parts bought directly from manufacturers. In this case, a base was bought from a manufacturer. “I modified it by making the arms longer, lightening it with carbon fiber parts, and adding features like a GPS, sensor systems, infrared and thermal cameras, and other parts required for mapping,” Wigmore shared.

Building their own drone allowed the researchers to repair it or replace parts when necessary, as sending it off to be repaired while in the field was not possible. It also allowed them to customize the drone to their needs.

A drone selfie taken by Wigmore, with the shadow of the drone in the bottom right corner (Source: Oliver Wigmore).

“No commercial manufacturers could promise that our equipment would work above an altitude of about 3000m, which is well below the glacier,” Wigmore said.

Using drones to study glaciers has advantages over conventional methods in terms of access to glaciers and spatial and temporal resolutions of data. These advantages have been further enhanced by hardware and software developments, which have made drones a relatively cheap, safe and accurate remote sensing method for studying glaciers at a finer scale. For example, Wigmore can build a UAV for about $4000, compared to the high cost of airplanes and satellites also used in remote sensing.

Wigmore and his team carried out aerial surveys of the glacier tongue (a long, narrow sheet of ice extended out from the end of the glacier) and the proglacial lake system (immediately beyond the margin of the glacier) in July 2014 and 2015. The drone was flown about 100 meters above the ice while hundreds of overlapping pictures were taken to provide 3-D images and depth perception.

High resolution (<5cm) Digital Elevation Models (DEMs) and orthomosaics (mosaics photographs that have been geometrically corrected to obtain a uniform scale) were produced, revealing highly heterogeneous patterns of change across the glacier and the lake. The data also revealed that about 156,000 cubic meters of ice were lost within the study period.

High resolution images showed rapid ice loss around exposed cliffs and surface ponds (Source: Wigmore and Mark, 2017).

The images revealed, for example, that the location of exposed cliffs and surface melt water ponds serve as primary controls on melt rates in the glacier tongue. Exposed cliffs lack the insulation of thick debris that are common on the glacier tongue, while ponds are less reflective than ice and absorb more solar radiation, causing higher melt rates.

The thickness of debris layers on the glacier constitute a secondary control. Thicker layers (often over 1m deep) provide insulation from solar radiation, while thinner layers increase the absorptivity of the surface to solar radiation.

The study also found that the upper section of the proglacial lake contains sections of glacier ice which are still melting. This suggests that the extent and depth of the lower section of the lake will increase as the ice continues to melt. This could increase the risk of GLOF, as expansion of the lake will bring it closer to the steep headwalls of the valley, which are potential locations for avalanche and rockfall debris.

Wigmore’s research is part of a series of larger projects still under publication that involve using drones to study glaciers, wetlands and proglacial meadows in the region. The results contribute to our understanding of hydro-social changes in the Cordillera Blanca, and how they can be managed.

Find out more about drone research here, or learn about Wigmore’s other research here.

Local Communities Support Mountain Sustainability

International capacity-building collaborations have been initiated to observe glaciers and develop action plans in the tropical Andes and Central Asia. A recent study titled “Glacier Monitoring and Capacity Building,” by Nussbaumer et al., highlights the importance of glaciers in the Andes and Central Asia for water management, hydropower planning and natural hazards. 

The Andes and Central Asia are among regions with the least amount of glacier observation data. For Central Asia, this was the result of the collapse of the Soviet Union from 1989 to 1991. In the Andes, institutional instability has been a continuous threat to the continuity of its glacier monitoring program. Monitoring glaciers in these regions can help mountain communities regulate their freshwater supply, manage the risks of glacier related hazards such as avalanches, and track declining runoff, all of which will have consequences for their socioeconomic development. Unfortunately, these two regions are also particularly vulnerable to the impacts of climate change.

A) Monitoring stations in the Cordillera Blanca of Peru, (B) In situ mass balance measurements in the Tien Shan, Kyrgyzstan (Source: Nadine Salzmann and Martin Hoelzle).
A) Monitoring stations in the Cordillera Blanca of Peru, (B) In situ mass balance measurements in the Tien Shan, Kyrgyzstan (Source: Nadine Salzmann and Martin Hoelzle).

As one of the seven South American countries that contain the Andes Mountain Range, Peru recently utilized its glacier monitoring capabilities to assess potential flood risks posed by rapidly changing glaciers in the Cordillera Blanca, a smaller mountain range in the Andes. 

Samuel Nussbaumer, the study’s lead author and a climate scientist, explained some of the hazards that changing glaciers can cause in Peru to GlacierHub. He explained that since there are “many new lakes emerging from retreating glaciers, ice could avalanche into these lakes,” which can be dangerous for the surrounding community. To reduce disaster risks in mountainous regions, glacier monitoring is crucial.

“If an event happens, and glacier data is already prepared, then the community can assess the risk and determine why the event happened,” continued Nussbaumer.

Another way that monitoring glaciers in these regions can help mountain communities is through freshwater supply regulation. The Cordillera Vilcanota in southern Peru provides water to the densely populated Cusco region. Glacier changes in Cordillera Vilcanota and other former Soviet Union countries in Central Asia, can have drastic consequences on the freshwater supply in mountain communities. 

The majority of freshwater on Earth, about 68.7 percent, is held in ice caps and glaciers. The authors argue that data-scarce regions like Central Asia and the Andes must strengthen their glacier monitoring efforts to inform water management. This will help buffer the high and increasing variability of water availability in these regions.

Young farmers in Peru (Source: Goldengreenbird/Creative Commons).
Young farmers in the mountains of Peru (Source: Goldengreenbird/Creative Commons).

Furthermore, in Central Asia, interest and awareness in rebuilding the scientific, technical, and institutional capacity has risen due to water issues in the region. Declining freshwater runoff is spurring glacier awareness in Central Asia, specifically in Kyrgyzstan. 

“Any assessment of future runoff has to rely on sound glacier measurements and meteorological data in order to get reliable results,” Nussbaumer said.

To sustain capacity-building efforts, Nussbaumer et al. recommend strengthening institutional stability and resources throughout both regions. Nussbaumer concludes that “direct glacier measurements (in situ data) are key to achieving contributions to sustainable mountain development.” 

Training youth to monitor and research local glaciers in their community could be a helpful approach. By monitoring how local glaciers change and evolve over time, communities in the Andes and Central Asia can strengthen their hazard management and freshwater regulation capacity. Local research capacities could also be improved by minimizing the bureaucratic barriers that block the implementation of glacial research projects.

Bringing the sheep home on the southern shore of Issy-Kol in Kyrgyzstan (Source: Peretz Partensky/Creative Commons).
Bringing the sheep home near the southern shore of Issyk-Kul in Kyrgyzstan (Source: Peretz Partensky/Creative Commons).

The World Glacier Monitoring Service (WGMS), which is supported by the United Nations Environment Programme, has a new project called “Capacity Building and Twinning for Climate Observing Systems” (CATCOS). Professor Martin Hoelzle of the University of Fribourg believes that CATCOS can support developing countries, and help them contribute to the international glacier research and monitoring community. CATCOS is working with developing countries like Kyrgyzstan and Uzbekistan so that they may contribute to worldwide glacier data monitoring networks.

Glaciers in the Andes and Central Asia ultimately enhance the resilience of mountain ecosystems through their freshwater provision and hazard management. Monitoring and protecting them benefits local mountain communities throughout Asia and South America. To learn more about capacity building and glacier monitoring in developing countries, visit the World Glacier Monitoring Service here. You can also find information about the study’s funding agency, the Swiss Agency for Development and Cooperation, here.

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.

Photo Friday: The Melting Andean Glaciers

In South America, the tropical glaciers of the Andes have been shrinking at an alarming rate, leaving the local communities at risk of losing an important water source. In Bolivia, for example, an Andean glacier known as the Chacaltaya Glacier disappeared completely in 2009, cutting off a valuable water resource to the nearby city of La Paz during the dry season.

In total, the Andes Mountains are home to nearly 99 percent of the world’s tropical glaciers, with 71 percent located in Peru’s Cordillera Blanca and 20 percent in Bolivia, according to UNEP. Other tropical glaciers are found in the equatorial mountain ranges of Venezuela, Colombia and Ecuador. Over the past 30 years, scientists estimate that the glaciers of the tropical Andes have shrunk by 30 to 50 percent. This rate of decline predicts that within 10 to 15 years many of the smaller tropical glaciers will have completely disappeared.

Take a look at GlacierHub’s collection of images of the rapidly retreating Andean glaciers.

 

The Chacaltaya glacier in Bolivia disappeared completely in 2009. 350.org climate activists visited the area in 2009 to raise awareness (Source: 350.org/Flickr).
After the Chacaltaya Glacier in Bolivia disappeared completely in 2009, 350.org climate activists visited the area to raise awareness about climate change (Source: 350.org/Flickr).

 

 

Laguna Glacier in Bolivia's Cordillera Real mountain range (Source: Alma Apatrida/Flckr).
Laguna Glacier in Bolivia’s Cordillera Real mountain range (Source: Alma Apatrida/Flckr).

 

 

The Antisana glaciers which are experiencing retreat, according to UNEP (Source: Sid Ansari/Flickr).
The Antisana glaciers in Ecuador are experiencing rapid retreat (Source: Sid Ansari/Flickr).

 

 

The Llaca Glacier of Peru (Source: dmitriylit/Creative Commons).
The Llaca Glacier of Peru (Source: dmitriylit/Creative Commons).

 

 

Looking up the Pacific coast of South America at the snow-covered Andes Mountains, which contains the world's largest glaciated area of the tropics (Source: Stuart Rankin/Flickr).
Looking up the Pacific coast of South America at the snow-covered Andes Mountains, the world’s largest glaciated area of the tropics (Source: Stuart Rankin/Flickr).

 

 

Quelccaya Glacier located in the Cordillera Blancas (Source: Edubucher/Creative Commons)
Quelccaya Glacier located in Peru, where glaciers have retreated by over 20 percent since 1978, according to scienceline.org (Source: Edubucher/Creative Commons).

 

 

Nevado Coropuna, Peru from the NASA International Space Station, 10/06/10 (Source: NASA/Flickr).
Nevado Coropuna, Peru, from the NASA International Space Station, 10/06/10 (Source: NASA/Flickr).

 

 

View of Nevado del Huila in Colombia. Four of Colombia's six glaciers are found on volcanos, (Source: Joz3.69/Flickr).
View of Nevado del Huila in Colombia. Only six glaciers remain in Colombia and four are found on volcanos (Source: Joz3.69/Flickr).

 

 

Climate Change Increases Flood Risk in Peru

The rising danger of glacial lake flooding in a warmer climate has important implications for humans and animal populations in Peru’s Cordillera Blanca. A recent study in CATENA by Adam Emmer et al. examined a large swath of nearly 900 high altitude Peruvian lakes in the mountainous Cordillera Blanca region, studying their susceptibility to outburst floods in light of modern climate change.

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A variety of glacial lake sizes in the Cordillera Blanca (Source: Elizabeth Balgord).

An outburst flood occurs when the dam containing glacial meltwater, usually comprised of either glacial ice or a terminal moraine (glacial debris lying at the edge of the glacier), fails. Glaciologist Mauri Pelto commented in the American Geophysical newsletter that the moraine dams are “just comprised of gravel, sand and clay dumped by the glacier” and “high water levels caused by upstream floods, avalanches or landslides can cause failure,” leading to major damage of the landscape. The team’s research elucidated that the incidence of glacial lake outburst flooding (GLOF) is increasing and the general distribution of alpine lakes is shifting upward in the region as temperatures warm. 

Knowing a lake’s size, configuration and type allows local water management in the Cordillera Blanca to be improved, according to Emmer et al. By mapping lakes with the classification of either moraine-dammed or bedrock-dammed, the team’s analysis can help local hydrological experts improve water management techniques for the changing distribution of alpine water. It also contributes to the scientific community’s overall understanding of ongoing environmental change.

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A large, high elevation glacial lake lying before the high Andes (Source: Elizabeth Balgord).

By studying the Cordillera Blanca region’s alpine lakes through a combination of remote sensing (high resolution aerial imagery and measurements) and field observations, Emmer’s team categorized 882 lakes by their size and altitude, ultimately referencing their findings with historical data to observe water redistribution over the last 60 years. Emmer et al. established that glacial lakes had expanded in size and number at higher elevations and disappeared at lower elevations since the 1951 study by Juan Concha in the same region. This finding confirms that environmental change and glacier retreat are strongly correlated in the high alpine.

Results from the analyses showed that from 1948 to 2013, lakes that remained in already deglaciated areas tended to be resilient and generally maintained water levels throughout the 65-year examination. Moraine-dammed lakes in particular resisted disappearing despite glacial retreat, suggesting that bodies of water dammed by materials other than ice were more adaptable to recently warmer temperatures. 

The team also noticed that despite the recent resiliency of moraine dammed lakes, glacial lake outburst flooding was caused predominantly by these dams in the early portion of the Cordillera Blanca’s glacial retreat, in the 1940s and 1950s. Flooding in more recent years has occurred in bedrock-dammed lakes. Although glacial lakes were recorded to have shifted from 4250-4600m in the late 1940s to predominantly above 4600m today, no statistically significant trend was established relating outburst flooding to any particular elevation.

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A research team gathered at the waters edge (Source: Elizabeth Balgord).

In order to reduce the risk of flood damage in local communities, Emmer et al. suggested continuous monitoring of young, developing proglacial lakes, using extensive flood modeling and outburst susceptibility assessments to account for future changes in the glacier. Understanding that the melting of glaciers is accelerating in a warming world, the need for more intensive local efforts in response to the threat of flooding is apparent.  

The Peruvian government has responded to high lake levels in the mountains of the Cordillera Blanca by “building tunnels and concrete pipes through the [weakest] moraines to allow lake drainage to safe levels,” according to Pelto. The government then rebuilds the moraines over the drainage system to strengthen it. By incorporating the monitoring techniques suggested by Adam Emmer, the government has the opportunity to manage and stay ahead of the flood risk as temperatures continue to rise. 

Glacial lake outburst flooding is hardly unique to the Peruvian landscape. This December, the Kathmandu Post illuminated the growing danger of GLOFs as the Nepalese Dhaulagiri Glacier recedes, creating a hazardous environment in the Mt. Nilgiri region. Researchers at the Chinese Institute of Mountain Hazards and Environment also established a strong link in Tibet between rising temperatures and glacial melting, contributing to more frequent and larger glacial lakes than in the past 50 years. With the growing number of alpine lakes and increased temperatures, ice dams are highly fragile and prone to failure.

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A variety of landscapes exist at different elevations in the Peruvian Andes (Source: Elizabeth Balgord).

Emmer et al.’s study offers an interesting evolutionary perspective on the state of the Cordillera Blanca. The study’s publication illustrates that even the planet’s most dramatic, seemingly unchangeable environments are plastic under the force of global climate change. The redistribution of alpine glacial lakes across the world’s mountainous regions indicates that the risk of outburst flooding should not be taken lightly. The team’s suggestions for future monitoring, to either mitigate the flooding hazard in populated regions or coordinate adaptation efforts, further illustrates the gravity of the situation. Although the risk of outburst flooding has only been studied in specific locations, the changing state of glacial lakes is already quantifiable and may be an effective proxy for monitoring the future extent of global warming.

Roundup: Tragedy in Antarctica, Antimony and Glacier Risks

Roundup: Tragedy, Antimony and Risk

 

Prominent Climate Scientist Dies in Antarctica

New York Times: “Gordon Hamilton, a prominent climate scientist who studied glaciers and their impact on sea levels in a warming climate, died in Antarctica when the snowmobile he was riding plunged into a 100-foot-deep crevasse. He was an associate research professor in the glaciology group at the Climate Change Institute at the University of Maine. He was camping with his research team on what is known as the Shear Zone, where two ice shelves meet in an expanse three miles wide and 125 miles long. Parts of the Shear Zone can be up to 650 feet thick and ‘intensely crevassed.’ Dr. Hamilton’s research, aided by a pair of robots equipped with ground-penetrating radar instruments, focused on the impact of a warming climate on sea levels. He was working with an operations team to identify crevasses.”

Learn more about the tragedy here.

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Professor Gordon Hamilton (Source: University of Maine).

 

Antimony Found in the Tibetan Glacial Snow

Journal of Asian Earth Sciences: “Antimony (Sb) is a ubiquitous element in the environment that is potentially toxic at very low concentrations. In this study, surface snow/ice and snowpit samples were collected from four glaciers in the southeastern Tibetan Plateau in June 2015… The average Sb concentration in the study area was comparable to that recorded in a Mt. Everest ice core and higher than that in Arctic and Antarctic snow/ice but much lower than that in Tien Shan and Alps ice cores… Backward trajectories revealed that the air mass arriving at the southeastern Tibetan Plateau mostly originated from the Bay of Bengal and the South Asia in June. Thus, pollutants from the South Asia could play an important role in Sb deposition in the studied region. The released Sb from glacier meltwater in the Tibetan Plateau and surrounding areas might pose a risk to the livelihoods and well-being of those in downstream regions.”

Read more about the research here.

Location map showing the sampling glaciers in the southeastern Tibetan Plateau. The red dots represent the location of the four investigated glaciers, and the size represents the average concentrations of Sb in the separate glacier.
Location map showing glaciers in the Tibetan Plateau (Source: Elsevier Ltd).

 

Managing Glacier Related Risks Disaster in Peru

The Climate Change Adaption Strategies: A recently edited book, “The Climate Change Adaptation Strategies – An Upstream – Downstream Perspective,” edited by Nadine Salzmann et al., has several chapters on glaciers. The chapter “Managing Glacier Related Risks Disaster in the Chucchún Catchment, Cordillera Blanca, Peru” discusses some of these glacier related risks: “Glacial lakes hazards have been a constant factor in the population of the Cordillera Blanca due their potential to generate glacial lake outburst floods (GLOF) caused by climate change. In response, the Glaciares Project has been carried out to implement three strategies to reduce risks in the Chucchún catchment through: (1) Knowledge generation, (2) building technical and institutional capacities, and (3) the institutionalization of risk management. As a result, both the authorities and the population have improved their resilience to respond to the occurrence of GLOF.”

Explore more related chapters here.

Evolution of the Lake 513 from 1962 to 2002 due to glacial retreat. Diagrams performed over aerial photographs from the National Aerial Photography Service Peru (left) and Google Earth (right) (Source: Randy Muñoz)
Evolution of the Lake 513 from 1962 to 2002 due to glacial retreat (Source: The Climate Change Adaptation Strategies).

New Study Offers Window into Glacial Lake Outburst Floods

A recent geological study has shed some light on the cause of a major, yet elusive destructive natural hazard triggered by failed natural dams holding back glacial lakes. The findings show how previously unrecognized factors like thinning glacier ice and moisture levels in the ground surrounding a lake can determine the size and frequency of Glacier Lake Outburst Floods, or GLOFs.

Palcacocha Lake in 2008, showing its enclosing moraine; the 1941 breach is visible in the lower right (Source: Colette Simonds/The Glacial Lake Handbook).

The risks of these glacial floods are generally considered increasingly acute across the world, as warming atmospheric temperatures prompt ice and snow on mountain ranges to retreat and to swell glacial lakes.

Landslides in moraines as triggers of glacial lake outburst floods: example from Palcacocha Lake (Cordillera Blanca, Peru), published in  Landslides in July 2016, centers its study on Lake Palcacocha in the Cordillera Blanca mountain region of central Peru.  Since Palcacocha is one of almost 600 lakes in the Cordillera Blanca mountain range dammed by glacial moraines, the population of the region lives under serious threat of GLOFs.

The Landslides article is a step in understanding a previously understudied geological phenomenon.  As little as five years ago scientists acknowledged the lack of research on the subject.

“We don’t really have the scientific evidence of these slopes breaking off and moraine stability… but personal observations are suggesting there are a lot of those…” said Ph.D. environmental historian Mark Carey in a 2011 video where he describes GOLFs.

 

Glacial Lake Outburst Flood risks do not always emanate from mountain glacier meltwater that flows downstream. As this study shows,  in some instances, trillions of gallons of water can be trapped by a moraine, a formation of mixed rock, which forms a natural dam.  A weakening over time, or a sudden event, such as a landslide, could then result in the moraine dam’s collapse.

The massive amount of water is suddenly then released, and a wall of debris-filled liquid speeds down the mountainside with a destructive force capable of leveling entire city blocks.

GLOFs have presented an ongoing risk to people and their homes dating back to 1703, especially in the Cordillera Blanca region, according to United States Geological Survey records.  In December of 1941, a breach in the glacial moraine restraining Palcacocha Lake led to the destruction of a significant portion of the city of Huaraz and killed approximately 5,000 people.

Looking north over Huaraz towards the highest region of the Cordillera Blanca (Source: Uwebart/CC).

Scientists and government agencies, like the Control Commission of Cordillera Blanca Lakes created by the Peruvian government following the 1941 GLOF, have recognized the need to better understand and control GLOFs.  The study found that as global temperatures rise and glaciers retreat, greater amounts of glacier melt water will continue to fill up mountain lakes, chucks of ice will fall off glaciers, and  wetter moraines will become  more prone to landslides.

The team of mostly Czech geologists and hydrologists (J. Klimeš; J. Novotný; I. Novotná; V. Vilímek; A. Emmer; M. Kusák; F. Hartvich) along with Spanish, Peruvian and Swiss scientists (B. Jordán de Urries; A. Cochachin Rapre; H. Frey and T. Strozzi) investigated the ability of a glacial moraine’s slope to stay intact, called shear strength, and modeled the potential of landslides and falling ice to cause GLOFs.

After extensive field investigations, calculations and research into historical events, the study found several causal factors that can determine the severity of a GLOF.  These include size and angle of entry of a landslide,  shape and depth of the glacial lake, glacier thickness and human preventative engineering such as canals and supporting dams.  Frequency and size of a landslide is determined by the stability of surface material, a characteristic called shear strength, which can be influenced by something as subtle as the crystalline shape of the predominant mineral in the rock.

The terminal and lateral moraines that contain Palcacocha Lake, showing the 1941 breach that released a GLOF that devastated the city of Huaraz (Source: John Harlin/The Glacial Lake Handbook).

The scientists determined that waves caused by moraine landslides and falling ice would most likely lead to over-toppings of the natural dam.  An example would be the 2003 Palcacocha Lake GLOF, which was caused by falling ice.  No one died in this flood, but sediment from the floodwaters blocked the Huaraz’s main water treatment facility, leaving 60 percent of the population without drinking water for six days.  Additionally, small events like the one in 2003 weaken the natural and manmade dams, which without monitoring could eventually give out and result in a more catastrophic occurrence.

Most recent measurements estimate Palcacocha Lake holds 4.5 trillion gallons of glacier meltwater, which is enough to fill approximately 6,800 olympic size pools.  The potential of a catastrophic flood following the collapse of the moraine dam is a serious threat to the growing city that lies beneath it.
“Climate-driven environmental changes may critically affect stabilities of slopes above glacial lakes, possibly triggering large moraine landslides,” write the authors in the article.  They call for continued monitoring of glacial lakes.