Glacier Retreat Drives 400% Lake Expansion Southern Alps, New Zealand 1990-2020

Glaciers of the Southern Alps of New Zealand have been losing ice volume since 1978, with an increasing rate in the last decade (Pelto, 2016).  Gjermundsen et al (2011) examined glacier area change in the central Southern Alps and found a 17 percent reduction in area mainly from large valley glaciers such as Hooker, Mueller, Tasman and Murchison Glacier. The NIWA glacier monitoring program noted that 30 percent of New Zealand’s ice that was existed in the late 1970’s has been lost in the past 40 years as snowlines have been rising. The retreat has been driven by a series of  increasingly warm summers (NIWA, 2019). The NIWA and University of Wellington 2020 snowline survey indicated improvement in 2020.  Lauren Vargo and Andrew Lorrey reported there was more retained snowcover compared to the very high snowlines in 2018 and 2019, despite the presence of ash/dust from Australian fires (NIWA, 2020).

Landsat images  from 1990 and 2020 of the Mueller (M), Hooker (H), Tasman (T) and Murchison (Mn) Glacier.  Red arrows indicate the 1990 terminus location, yellow arrows the 2020 terminus location and pink arrows the upglacier extent of debris cover in 1990.

If we look back to the 1972 Mount Cook map, see below, no lakes are evident at the terminus of Hooker (H), Mueller (M), Tasman Glacier (T), or Murchison Glacier that all drain into Lake Pukaki, pink dots indicate terminus location. In 1990 four lakes had developed one in front of each retreating glacier with a combined area of 2.5 km2.  By 2020 the combined lake area is 12.9 km2.

1972 Map of region when Tasman, Mueller and Hooker Glacier lacked proglacial lakes.

Mueller Glacier has had a 2,300 meters retreat from 1990-2020, which will continue in the future as the lower 1.2 kilometer section of the glacier is stagnant. Mueller Lake area was under 0.2 square kilometers in 1990, expanding to 1.9 square kilometers by 2020. Mueller Glacier’s lower section is not a typical convex valley glacier, but a concave reach of debris covered ice with significant melt valleys and hollows indicating stagnation in the lowest 1.6 kilometer.  In 1990 a fringing discontinuous area of water along the southern glacier margin existed. By 2004 the Mueller Glacier Lake had expanded to a length of 700 meters.  Mueller Lake in 2010 had a surface area of 0.87 square kilometers and a maximum depth of 83 meters (Robertson et al, 2012). By 2015 the lake had reached 1,800 meters in length. From 2015-2020 the terminus collapsed into the lake with icebergs and other attached ice remnants.  Terminus images from 2018, taken by Jill Pelto, indicate the high turbidity of the lake, which is expected from a debris covered ablation zone.

Mueller Glacier terminus collapse in 2018, image from Jill Pelto.

Hooker Glacier retreated 1,350 m from 1990 to 2020 with the retreat enhanced by calving in Hooker Lake. The lake had an area of 0.5 square kilometers in 1990, expanding to 1.5 square kilometers by 2020. The retreat was faster during the earlier part of this period with lake area reaching 1.22 square kilometers by 2011 (Robertson et al.,2013). Hooker Glacier has a low gradient which helps reduce its overall velocity and a debris covered ablation zone reducing ablation, both factors increasing response time to climate change  (Quincey and Glasser 2009). Hooker Lake which the glacier ends in began to form around 1982 (Kirkbride, 1993). The peak lake depth is over 130 meters, with the terminus moving into shallow water after 2006 leading to declining retreat rates (Robertson et al, 2012). The debris cover now extends ~2 kilometers further upglacier than in 1990.

Tasman Glacier retreated 4,900 meters from 1990 to 2020 primarily through calving into the expanding proglacial lake. In 1990 Tasman Lake had an area of 1.7 square kilometers, expanding to 7.1 square kilometers by 2020.  Dykes et al (2011) note a maximum depth of 240 meters, and an annual growth rate of 0.34 square kilometers. The proglacial lake at the terminus continues to expand as the glacier retreats upvalley. The lake is deep with most of the lake exceeding 100 meters in depth, and the valley has little gradient, thus the retreat will continue. It has been noted by researchers at Massey University that the lake can expand in this low elevation valley another 9 kilometers, and that at the current rate this could occur over two decades. The debris cover now extends ~1.5 kilometers further upglacier than in 1990.

Canals draining from Lake Tekapo to Lake Pukaki then upriver of Lake Benmore

Murchison Glacier has retreated 2,700 meters From 1990 to 2020.  In 1990 the lake had an area of under 0.2 square kilometers, expanding to 2.5 square kilometers by 2020. The rapid retreat will continue as 2010, 2013 and 2015 imagery indicate other proglacial lakes have now developed 3.5 km above the actual terminus. The debris cover now extends ~2 kilometers further upglacier than in 1990.

For each glacier debris cover now extends further upglacier which along with rising snowlines highlights the expansion of the ablation area, that also drives volume loss, retreat and lake expansion.

Canal at Ohau hydropower, image from Jill Pelto.

Glacier runoff is a key hydropower water resource. Water from Lake Pukaki is sent through a canal into the Lake Ohau watershed and then through six hydropower plants of the Waitaki hydro scheme: Ohau A, B and C. Benmore, Aviemore and Waitaki with a combined output of 1,340 megawatts.  Meridian owns and operates all six hydro stations located from Lake Pūkaki to Waitaki.  Interestingly salmon have been introduced into the Waitaki River system for fishing near its mouth, though Lake Pukaki itself has limited fish.

This post by Mauri Pelto originally appeared on his blog From a Glacier’s Perspective, published by the American Geophysical Union.

Read More on GlacierHub:

Video of the Week: “Return to Natural––Documenting the Tasman Glacier”

Request for Submissions to the Global Report of Indigenous Knowledge and Local Knowledge on Climate Change 2020

Roundup: COVID-19 in Glacier Regions

Video of the Week: “Return to Natural––Documenting the Tasman Glacier”

This week’s Video of the Week is a short film featuring award-winning photographer and natural progressive, Chris Burkard, on a quest to take a single photograph that represents humans’ relationship with nature. The film, Return to Natural, was produced by New Zealand outdoor apparel brand, Icebreaker, who invited Burkard to the Tasman Glacier to seek and capture the photo. In that search for the right image, the film was created.

The 12-minute movie follows Burkard and his team over the course of five days as they hike, ski, boat, and fly above the Tasman, becoming increasingly intimate with the glacier. On the final day Burkard found the image he was looking for––one that would challenge peoples’ perspective of nature. “It hit me when I was taking the photo of the lake,” Burkard said.

“It was the literal open wound of a melting glacier,” Burkard said of the glacial lake, which is younger than the 34-year old photographer himself. “The lake was in fact new, only 30 years old. Created from the run-off from the ever melting glacier.”

About a year after Return to Natural was filmed, the Tasman Glacier was the site of a heartbreaking video that went viral in January when ash and soot from the Australia bushfires turned the sky orange and darkened the ice. The fallout will accelerate the melt of Tasman, which the docu-film reported is already receding 477-822 meters each year. The dire forecast for Tasman is underscored by a recent study that showed fires in the Amazon in 2010 caused a 4.5 percent increase in water runoff from Zongo Glacier in Bolivia alone.

Earlier this year GlacierHub reported on Burkard’s new book At Glacier’s End in which he and author Matt McDonald documented Iceland’s glacial rivers by air to advocate for their protection as part of a new national park covering most of the country’s interior. In the book, as with the short film, Burkard’s ‘it’s not the photo––it’s what you have to say about it’ mantra is unmistakably consistent.

“We have the potential to reduce our impact, but it starts with changing our perspective and moving to natural alternatives,” Burkard said. “We need people to re-examine their perceptions and individual choices…particularly the things that might not be so obvious.”

Read More on GlacierHub:

At Glacier’s End: Protecting Glacial Rivers in Iceland

Video of the Week: Smoke and Ash Choke Tasman Glacier in New Zealand

Photo Friday: New Zealand’s Tasman Glacier

Video of the Week: Smoke and Ash Choke Tasman Glacier in New Zealand

Australia is experiencing the worst fire season in modern times. Millions of hectares of forest and thousands of homes have burned and more than 20 people have perished. The environmental impacts are yet to be tabulated, but experts say one billion animals may have died on the continent, which already has the highest extinction rate in the world.

While no glaciers remain on Australia, the impacts of the fires on glaciers more than 1,000 miles away are already being felt. This week’s Video of the Week, showing the impact of Australia’s bushfires on New Zealand’s Tasman Glacier, is one of the most viral glacier videos ever. The footage was viewed 653,000 times on Twitter alone at the time of publication––just one week after it was shared.

Video Credit: Andy Hoare

Andy Hoare, who has been a guide on the Tasman Glacier for the past three years and who shot the footage on New Year’s Day 2020, said the group have never seen anything like it. “I didn’t expect the smoke to get as bad as it did,” Hoare told GlacierHub. “It felt quite depressing standing there, especially because you can already the massive retreat that our glaciers have already experienced. I think it felt quite symbolic of what’s happening to our environment around the world.”

The 21-second clip shows tourists milling about on the ice. Hoare’s mother, Twitter user @MissRoho, shared the video with the caption “This the view from the top of the Tasman Glacier NZ today––whole South island experiencing bushfire clouds. We can actually smell the burning here in Christchurch. Thinking of you guys.”

The long term impacts of the sooty fallout darkening the surface of New Zealand’s glaciers remains to be seen. But if the Amazon forest fires are any analog, New Zealand’s glaciers can be expected to melt significantly faster. Fires in the Amazon in 2010 caused a 4.5 percent increase in water runoff from Zongo Glacier in Bolivia alone.

Melt rate is critical because where there are glaciers there are people––and biodiversity––reliant upon the slow release of water from glacial reservoirs. Nearly two billion people depend on runoff from Himalayan glaciers in southeast Asia and some towns in Peru receive as much as 85 percent of their drinking water from glaciers during times of drought. Too much melt too fast without replenishment is bad for people, biodiversity, and glaciers.

Hoare did not expect the video to take off the way it did. “I’m glad the footage could at least in a small way make people aware of how the fires affected our glaciers and also maybe think about the connection between the fires, emissions, coal mining, and how it effects the planet.”

Read More on GlacierHub:

Photo Friday: Bushfires in Australia Continue to Devastate New Zealand Glaciers

Amazon Fires Quickening Glacier Melting in Andes

Last Remaining Glaciers in the Pacific Will Soon Melt Away

Roundup: The Glacier Compensation Effect, Amazon Fires Melt Andean Glaciers, and Australia’s Bushfires Accelerate Melt in New Zealand

Characterizing the Relation Between Interannual Streamflow Variability and Glacier Cover

A new study confirmed the theory that streamflow variability is dependent on relative glacier cover. From the abstract: “Meltwater from glaciers is not only a stable source of water but also affects downstream streamflow dynamics. One of these dynamics is the interannual variability of streamflow. Glaciers can moderate streamflow variability because the runoff in the glacierized part, driven by temperature, correlates negatively with the runoff in the non‐glacierized part of a catchment, driven by precipitation, thereby counterbalancing each other. This is also called the glacier compensation effect (GCE), and the effect is assumed to depend on relative glacier cover. Previous studies found a convex relationship between streamflow variability and glacier cover of different glacierized catchments, with lowest streamflow variability at a certain optimum glacier cover. In this study, we aim to revisit these previously found curves to find out if a universal relationship between interannual streamflow variability and glacier cover exists, which could potentially be used in a space‐for‐time substitution analysis.”

Read the study here.

Amazon Fires Quickening Glacier Melting in Andes

In a new paper published November 28, 2019, in the journal Scientific Reports, a team of researchers has outlined how smoke from fires in the Amazon in 2010 made glaciers in the Andes melt more quickly.

Read the story here.

The Zongo glacier is found on the slopes of Huayna Potosi, one of Bolivia’s highest mountains (Source: Ryan Michael Wilson/Shutterstock)

Soot From Australia Bushfires Settles on New Zealand Glaciers

On December 13, GlacierHub published “Bushfires in Australia Blanket New Zealand Glaciers in Soot.” Since then, the fires in Australia have continued to grow and their fallout is increasingly darkening the surface of glaciers in New Zealand. Media outlets including The New York Times, Washington Post, CNN, and The Guardian, among others, are reporting on the tragedy indirectly befalling New Zealand’s glaciers.

Read the story here.

On January 1, 2020, the Operational Land Imager (OLI) on Landsat 8 acquired a natural-color image (above) of thick smoke blanketing southeastern Australia along the border of Victoria and New South Wales (Source: NASA).

Read More on GlacierHub:

Kerguelen Island Glacier Retreat Expands Lake District

Photo Friday: Glaciers Smile Down on Electric Ferries

Crowded Backcountry Ski Slopes Increase Risk of Skiers Endangering Each Other

Photo Friday: Bushfires in Australia Continue to Devastate New Zealand Glaciers

On December 13, GlacierHub published “Bushfires in Australia Blanket New Zealand Glaciers in Soot.” Since then, the fires in Australia have continued to grow and their fallout is increasingly darkening the surface of glaciers in New Zealand. Media outlets including The New York Times, Washington Post, CNN, and The Guardian, among others, are reporting on the tragedy indirectly befalling New Zealand’s glaciers. The following story was originally written by GlacierHub writer, Zoë Klobus, with updated figures and images:

Bushfires raging in Australia have taken their toll on New Zealand’s glaciers. Smoke and dust from the fires drifted across the Tasman Sea and settled on glaciers in New Zealand more than 1,300 miles away. Ash covering glaciers in New Zealand is visible in photos published to Twitter. In the images, the snow and ice appears as a pinkish color.

Australia has experienced a severe bushfire season. At least 18 people have died, over 1,000 homes destroyed, millions of livestock lost, and over 15 million acres of land has burned. The smoke and dust-laden glaciers of New Zealand are representative of the second-order effects of the bushfires in Australia.

The distance the smoke and ash have traveled and the extent to which they have blanketed glaciers in New Zealand speaks to the severity of the Australian bushfires. This coating of smoke and ash poses a significant threat to New Zealand’s glaciers. It settles as black carbon, which darken glaciers’ snow and ice, absorbing heat and contributing to increased rates of melting and extending the melt season.

Read more on GlacierHub:

Amazon Fires Quickening Glacier Melting in Andes

Wildfires Melt Glaciers From a Distance

Photo Friday: Mount Baker Amid Haze from Fires

Photo Friday: New Zealand’s Tasman Glacier

This week’s Photo Friday features the Tasman Glacier in the Southern Alps of New Zealand’s South Island. At over 23 kilometers, the glacier is the longest of New Zealand’s more than 3,000 glaciers.

The photographer, Ryan Force, took the image from the Tasman Glacier viewpoint. Force and his wife, Marissa, honeymooned on the island by campervan. They intended to park near Mount Cook, the country’s highest peak, and hike to a promontory to view the glacier. But heavy rains in the region days earlier washed out a bridge on the road to the access point. The photo below was as close to the Tasman Glacier as the newlyweds were able to get.

The rock and debris covered Tasman Glacier seen from the southwest shore of Tasman Lake (Source: Ryan Force).

The Tasman Glacier is in rapid retreat. The body of milky grey water in the foreground of Force’s photo is Tasman Lake, which formed as the glacier’s ice melted and continues to grow as the glacier recedes.

In 1973 there was no lake in front of the Tasman Glacier, according to Martin Brook, a lecturer in physical geography at New Zealand’s Massey University. The lake is now 7 kilometers long, 2 kilometers wide, and 245 meters deep.

A significant ice calving event in February of this year created a two-meter surge that damaged a jetty and several boat trailers on Tasman Lake, the BBC reported.

A sign at the Tasman Glacier lookout informs tourists of the glacier’s decline. New Zealand’s Department of Conservation uses the visual display of their rapidly retreating glaciers as an opportunity to raise awareness about climate change.

A sign board installed by New Zealand’s Department of Conservation documents the Tasman Glacier’s ablation (Source: Ryan Force).

“We felt a bit defeated,” Force told GlacierHub of the experience. “I felt a little frustration that in the next 50 years, this beautiful landscape might be gone entirely because we as a species put our heads in the sand and refused to take action.”

A 2015 study on the implications of climate change for glacier tourism in New Zealand found glaciers to be a fundamental motivation for visitors, finding a “last chance dimension” luring visitors to the glaciers.

New Zealand’s Department of Conservation estimated that 945,000 people visited Aoraki/Mount Cook National Park in 2018. The surge in visitors to the park, which contains the Tasman Glacier, is a 17.5 percent increase from the previous year.

An aerial photo of a helicopter landing on a glacier in New Zealand’s Southern Alps (Source: Ryan Force).

Although travelers produce a substantial carbon footprint through last-chance tourism, it may help bolster the sense of place attachment and identity that encourages tourists to engage in carbon offsetting, GlacierHub reported last month. People sometimes build personal connections to places they visit, and this value they put on locations may lead them to take meaningful action to preserve them.

“It was so valuable to actually see it firsthand,” said Force. “This was the first time I saw with my own eyes what the results looked like, instead of reading about them in an article or seeing it in a documentary. I walked away wanting to do more.”

Read more on GlacierHub:

Glaciers Get New Protections with Passage of Natural Resources Act

Glaciers Account for More Sea Level Rise Than Previously Thought

The Dead of Mount Everest Are Seeing the Light of Day


Video of the Week: Shedding Light on Glaciers

This week, journey to New Zealand’s largest glacier as Heath Patterson captures photographers Vaughan Brookfield and Tom Lynch and their attempt to literally shine a light on the impact of climate change through visual art.

After remaining at a constant length for all of its recorded history in the 20th century, the Tasman Glacier is now in a period of retreat. Brookfield and Lynch projected images on to the rapidly receding glacier to “remind people of the effects humans are having on the environment.”

This project was made possible by Canon Australia’s “Show Us What’s Possible” creative incubator. The story was also featured in The Guardian.

Read more glacier news at GlacierHub:

The Swiftness of Glaciers: Language in a Time of Climate Change

Melting Glaciers Create Uncertain Future for Xinjiang

The Curious Case of New Zealand’s Shrinking Glaciers

Roundup: Hazard Films, Water Scarcity, and Peace Building

Roundup: Films, Water and Peace

 

Films Raise Awareness in Volcanic Regions

From Science Direct: “The medium of film is well established for education and communication about hazardous phenomena as it provides engaging ways to directly view hazards and their impacts… Using volcanic eruptions as a focus, an evidence-based methodology was devised to create, use, and track the outcomes of digital film tools designed to raise hazard and risk awareness, and develop preparedness efforts. Experiences from two contrasting eruptions were documented, with the secondary purpose of fostering social and cultural memories of eruptions, developed in response to demand from at-risk communities during field-based research. The films were created as a partnership with local volcano monitoring scientists and at-risk populations who, consequently, became the leading focus of the films, thus offering a substantial contrast to other types of hazard communication.”

Read more about it here.

A map of St. Vincent showing the main road, water courses and volcanic hazard zones (source: Hicks et al.).

 

An Overview of Water Issues in Mountain Asia

From Cambridge Core: “Asia, a region grappling with the impacts of climate change, increasing natural disasters, and transboundary water issues, faces major challenges to water security. Water resources there are closely tied to the dramatic Hindu-Kush Himalayan (HKH) mountain range, where over 46,000 glaciers hold some of the largest repositories of fresh water on earth. Often described as the water tower of Asia, the HKH harbors the snow and ice that form the headwaters of the continent’s major rivers. Downstream, this network of river systems sustains more than 1.3 billion people who depend on these freshwater sources for their consumption and agricultural production, and increasingly as a source of hydropower.”

Learn more about the HKH area here.

View from Cholpon-Ata across the lake towards the Tian-Shan Mountains in Asia (source: Thomas Depenbusch/Flickr).

 

The Pathway of Peaceful Living

From Te Kaharoa: “This paper traces the peacebuilding efforts of Anne Te Maihāora Dodds (Waitaha) in her North Otago community over the last twenty-five years. The purpose of this paper is to record these unique localized efforts, as a historical record of grass-roots initiatives aimed at creating a greater awareness of indigenous and environmental issues… The paper discussed several rituals and pilgrimages. It describes the retracing of ancestral footsteps of Te Heke Ōmaramataka (2012), the peace walk at Maungatī (2012) and the Ocean to Alps Celebration (1990). This paper also discusses the genesis behind cultural events such.”

Explore more about the Maori nation here.

Tasman Glacier at Mount Cook NP, New Zealand (source: Paco/Flickr).