Warming Rivers Are Causing Die-Offs Among Alaska Salmon

Dead chum salmon lined snow-fed and rain-fed rivers across Alaska, where lethally high temperatures and low water levels prevented migration. With their original habitat under threat by global warming, cold glacial water is becoming more necessary for the survival of salmon.

Salmon are born in freshwater rivers. They swim to the ocean to spend their adulthoods, and then return to the rivers to spawn four or five years later, Holly Carroll, a Yukon-focused biologist at Alaska’s Department of Fish and Game, told GlacierHub.

Salmon felt the effects of July’s record-breaking temperatures in Alaska this summer as they struggled to reach their spawning grounds. They do not eat once they begin the journey back to the rivers, Carroll said, meaning that they have a limited amount of energy to make the trip. “So if they then encounter really warm water, it puts their body under much more stress,” she said. The heat speeds up their metabolisms so that salmon can run out of energy and die mid-journey.

As salmon suffer in Alaska’s warming snow- and rain-fed rivers, some scientists are looking to glaciers to predict the future of these fish. 

The Die-Offs

According to NPR, the largest die-off occurred in the Koyukuk River, a tributary of the Yukon River. The dead salmon count was in the thousands to ten thousands, Stephanie Quinn-Davidson, director of the Yukon River Inter-Tribal Fish Commission, told GlacierHub. She put together a team of scientists and surveyed 200 miles of the river to count the salmon—they found at least 850 dead —and confirm, by cutting the fish open, that they had not spawned and had no signs of disease.

“The die-off coincided with record-breaking temperatures in Alaska,” she wrote in a Facebook post.  Some places on the Koyukuk reached 90 degrees Fahrenheit from July 7 to July 11—25 degrees above average. July 12, she noted, was when when locals began seeing dead chum salmon floating downriver.

Quinn-Davidson’s team examines salmon along the Koyukuk River. (Source: Stephanie Quinn-Davidson)

The Koyukuk is fed by snow and rain, Carroll told GlacierHub. This year, the snow melted quicker, leaving the river with record-high water levels earlier in the season and very low levels in the summer. The drought also deprived the river of much-needed rainwater.

The Bristol Bay area also experienced salmon die-offs, particularly in the Igushik River, which flows from Amanka Lake into Bristol Bay. Tens of thousands of fish were found dead in the Igushik, according to Timothy Sands, area management biologist of the Nushagak/Togiak region.

An early-melting snowpack led to low water levels, aiding in the rise of temperatures, Sands told GlacierHub. The snowpack usually continues to melt through June, he said, but this year it vanished in May. Lower water levels enhanced the heating of these waters which are already susceptible to warming as a muddy river in the tundra.

While Koyukuk salmon died of heat stress, the Igushik salmon died of oxygen depletion, Sands said. The river is prone to oxygen depletion due to its geography: The elevation drop in the river is minimal, and so the flow of the river is slow and tidal. This means less recycling of water and less replenishment of oxygen.

High temperatures increase a salmon’s metabolism, so that it increases its need for oxygen at a time when there is less of it in the water, Mary Catherine Martin, communications director for Salmon State, told GlacierHub.

Even with the die-off, Sands said, the river reached its escapement goal, which is the number of fish that are required to reach their  spawning grounds in order to ensure a new generation of fish. “It’s a healthy system,” he said, noting that this year’s run was the third highest since 1884. 

Dead chum salmon lined the Koyukuk River this July. (Source: Stephanie Quinn-Davidson)

Habitat in Danger

Sue Mauger, science director at Cook InletKeeper, has been monitoring stream temperatures in Alaska’s Cook Inlet since 2002. She told GlacierHub that she was surprised there weren’t more salmon die-offs this summer, considering that the waters reached temperatures that are considered lethal for salmon. In the Deshka River, she said, temperatures were warmer than those expected for 2069 under a worst-case climate model.

The fish survive by finding cold-water refugia, which are pockets of cold water in which the salmon can wait for temperatures to diminish. In the case of the Deshka, she said, a connected glacial area provided this space for salmon to wait out the heat.

In deep rivers, groundwater inflows, side channels and springs provide the same service. But when rivers experience low water levels, “you don’t have those deep cold refuges, then the salmon don’t have anywhere to hang out and wait until the temperatures start to drop,” Quinn-Davidson told GlacierHub.

Development also harms this habitat, Mauger told GlacierHub. Abstaining from building near rivers is “a decision that we need to make,” she said.

In Bristol Bay, the Environmental Protection Agency took a step towards the opposite decision this month by allowing a mining project to progress unopposed, despite the risks to salmon.

A New Glacial Habitat

“This summer has a lot of the components that we should expect to see in the future, and that includes having a warm spring, which means that however much snowpack we have is going to melt out earlier,” Mauger said.

Salmon are finding new spawning grounds in the vast habitat of cool streams that Alaska’s receding glaciers are leaving behind. In Glacier Bay, Kenai Fjords National Park, and other areas, salmon are beginning to inhabit these streams that benefit from ice melt all summer long.

But the situation is more complicated, according to Chris Sergeant, a researcher at the University of Alaska, Fairbanks who studies the effects of temperature and other stream conditions on salmon. “While a glacial river might protect salmon from warm water temperatures [in the summer], they may not necessarily be the best place for salmon to grow in rear during all the other months,” he said. In the winter, he told GlacierHub, young salmon grow faster in warmer waters. Since glacial streams are prone to flooding, spawning there also means a risk that the eggs will be swept away in water.

In the summer, he said, “some of these fish will live in the glacial systems for a few months, and then they’ll move into a smaller tributary fed by rain or snow” for the remainder of the year.

These are juvenile fish, though. After salmon spend their adulthoods in the ocean, they return to the exact rivers they were born in to spawn the next generation, for better or worse. “A lot of studies recently suggest that not only do they return to the same river where they were born, but they also spawn… within twenty feet of where they were born,” Martin said.

Glacial mainstem rivers (the brown water) mix with other habitats in the Taku River watershed, located between Alaska and British Columbia. Preserving a diversity of habitats will help ensure healthy salmon populations continue in the face of climate change, Sergeant told GlacierHub. (Source: Chris Sergeant for the University of Alaska Fairbanks and the University of Montana)

Response to This Year’s Die-Offs

There is not much to be done about the die-offs besides collecting data, Carroll said. The locals—many of whom are native Alaskans—are key to this. With extensive tributaries, the Dept. of Fish and Game relies on locals to report natural events in the river.

In the case of the Koyukuk river, Quinn-Davidson said, the expedition she organized would not have happened without the Yukon River Inter-Tribal Fish Commission, which represents over thirty federally recognized tribes along the Yukon River. “Alaska is currently experiencing a pretty major budget crisis,” she said. “It was good that our organization could step in, bring us all together, provide the funding to take us all out there, and more properly document what was going on.”

Salmon are of great importance to the local communities, who rely on the fish for food and their livelihoods. A commercial fishery for chum salmon is located on the lower part of the Koyukuk. “That fishery really helps the local economy because most people that live along the Yukon are native Alaskans and there’s not a lot of local jobs,” she said.

“People were able to meet their needs for salmon this year despite the die-offs,” Quinn-Davidson said. “Now the big question is, how much will this die-off impact future years of salmon returning—because those salmon didn’t end up spawning.”

According to Carroll, it’s likely that the next generation will not be negatively affected, since fewer young salmon can minimize  over-competition.

The die-offs did not pose an existential threat to salmon this year. According to Martin, the multitudes of dead salmon, along with the state’s wildfires, were a reminder that “climate change is happening, and it’s real, and it’s going to be an increasing part of the conversation here in Alaska.”

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Video of the Week: The Emerging Dangers of Glacier Tourism

The landscapes that climate change is impacting the most are emitting an intense gravitational pull on some tourists and outdoors enthusiasts.

Glaciers, whether in the high-mountains or polar regions, are melting. Tropical rainforests are disappearing. Coral reefs are deteriorating. And, wherever those habitats are under threat, some tourists are seeking them out before they become unrecognizable or completely relegated to memory.

And that’s making so-called last-chance tourism a sometimes dangerous endeavor.

Consider Alaska.

On August 1, officials in the city of Valdez reported that they discovered the bodies of three European boaters who appeared to have been killed by debris from melting glaciers.

“[T]he victims were identified by the city as two Germans and an Austrian and were found dead on Tuesday morning in Valdez Glacier Lake, about 120 miles (193 km) east of Anchorage,” according to Reuters.

The area “was littered with floating icebergs, glacial slush, and challenging terrain for recovery,” the news agency reported.

“Those conditions, plus the location of the remains near the toe of Valdez Glacier, suggested that falling glacial ice killed the boaters,” Sheri Pierce, a spokeswoman for the city government, said in a statement.

Now This offers another example in an August 20 video. In it, a glacier face is seen collapsing, drenching nearby kayakers, who are shooting the video. The footage then becomes shaky as the wake from the collapse of the glacier generates waves, forcing the kayakers to make a hasty retreat.

“Oh my God. We’re lucky to be alive,” says one of the kayakers.

Read More on GlacierHub:

The Funeral for Iceland’s OK Glacier Attracts International Attention

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Photo Friday: Alaska’s Arrigetch Glaciers

Alaska’s Gates of the Arctic National Park was established in 1980 and is comprised of 8.4 million acres of rugged landscape. Wilderness advocate Robert Marshall gave the park its name, citing two peaks, Frigid Crags and Boreal Mountain, as the gates from the central Brooks Range to the Arctic.

The elements and tectonic shifts have given shape to Gates of the Arctic.

So, too, have glaciers.

The glaciers of Gates of the Arctic are unique—they are the only ones lying entirely above the Arctic Circle. Among them are those snaking through the Arrigetch Peaks of the Brooks Range.

Remnants can be seen of the glaciers that carved the dramatic Arrigetch Peaks in the Brooks Range. (Source: National Parks Service)

Arrigetch means “fingers of the outstretched hand” in the Inupiat language.

Runoff from the park’s glaciers feeds several rivers that cross Gates of the Arctic, including the Alatna, John, Kobuk, Noatak, North Fork Koyukuk, and Tinayguk. Those rivers provide sustenance to the park’s rich plant and animal life, which, in turn, has provided resources for people going back 13,000 years, when nomadic hunters and gathers inhabited the region.

The Arrigetch Peaks of Alaska’s Gates of the Arctic National Park. (Source: Wikimedia Commons)

The park’s glaciers, like many others in Alaska and within the US parks system, are retreating. The National Park Service estimates the Arrigetch Glaciers have receded about a quarter of mile in the past century. And, as those glaciers shrink, salmon populations are declining, which impacts the livelihoods of communities living and working downstream.

A map of Gates of the Arctic National Park (Source: National Park Service)

The Arctic is warming at twice the rate as lower latitudes, which is melting land and sea ice, as well as threatening biodiversity.

Read More on GlacierHub:

Alaskan Glaciers Are Melting Twice as Fast as Models Predicted

Park Officials Remove Signs Warning That Some Glaciers Will Disappear by 2020

Snow Algae Thrives in Some of Earth’s Most Extreme Conditions

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Alaskan Glaciers Are Melting Twice as Fast as Models Predicted

Scientists from the University of Oregon recently found that the underwater section of a glacier in southeast Alaska is melting at rates up to two orders of magnitude greater than those predicted by theory.  The results, published in the journal Science, challenge the current models used to predict the melting of tidewater glaciers worldwide.

Tidewater glaciers play an important role in maintaining glacier stability, and their melting is accelerating overall ice loss in Greenland and in Antarctica. According to the study, no one has yet directly measured the melting of the underwater portion of a tidewater glacier. Instead, scientists have relied on untested theoretical models.

This diagram of a typical marine-terminating glacier in Greenland is from Oceans Melting Greenland (OMG), a project to investigate the extent to which the ocean is melting Greenland’s glaciers from below. (Source: NASA Jet Propulsion Laboratory)

Glaciers that terminate in the ocean come in two forms: Ice shelves, which are horizontal slabs of ice that extend into the ocean, and tidewater glaciers, which end in relatively vertical ice faces, Rebecca Jackson, one of the study’s authors, told GlacierHub.

Jackson explained that observing tidewater glaciers from below is difficult. Ice shelves retreat horizontally, and this can be seen by satellites and other remote sensing techniques. But the horizontal retreat of a tidewater glacier’s vertical face is too slight to be detected with remote sensing.

With funding from the National Science Foundation, the University of Oregon scientists used a new method to directly observe tidewater glacier melt: creating and comparing sonar images of the glacier over time. They studied the melting of Alaska’s LeConte Glacier, mainly because of its accessibility, Dave Sutherland, the lead author of the study, told GlacierHub. The physics of the interactions between glacier and ocean at LeConte are the same as in other systems around the world, including tidewater glaciers in Greenland, Patagonia, and the west Antarctic, he said.

They made observations at the glacier six times from 2016 to 2017, Sutherland told GlacierHub.

The glacier-ocean boundary at LeConte. (Source: Dave Sutherland, University of Oregon)

The results were striking. “We have direct observations that show melt rates are much higher than we we expected,” Jackson told GlacierHub.

This doesn’t change the amount of glacier ice currently being lost to the ocean, she explained. “Right now we know, to a pretty good degree, how much glaciers are losing ice and raising sea level,” Jackson said. “That’s a pretty well-documented quantity and our results don’t change that.”

Instead, the study illuminates what portion of the glacier ice being lost to the ocean is the result of underwater ice melting as opposed to calving—the process by which chunks of the glacier break off and float into the ocean as icebergs. “The sub-marine melt rates are higher than we expect, which means that the amount calving off is slightly less,” said Jackson.

That means that the ocean is playing a larger role than expected in the loss of water-terminating glacial ice, Sutherland told GlacierHub.

With a warming ocean, this news suggests that tidewater glaciers could disappear quicker in response to climate change than previously thought, Jackson explained. “There’s a hypothesis that ocean warming can increase submarine melting and then that triggers a glacier acceleration that deposits more ice overall into the ocean,” she said.

In other words, if the portion of glacier submerged in ocean water melts quicker, then the rate at which the glacier flows toward the ocean will increase, and the rate of calving will increase as well.

“You could imagine that if sub-marine melting was depth-dependent, you could undercut the glacier and destabilize it, leading to increased calving,” Sutherland told GlacierHub. And indeed their study found that the melt rates of the glacier were depth-dependent.

A picture of LeConte Glacier taken during the study. (Source: Dave Sutherland, University of Oregon)

“Ultimately what we want to be able to do is start answering questions like, if the ocean warms by one or two degrees, how will that affect the glacier?” said Jackson. And in order to do that, the faulty model must be replaced by a more accurate theory. The same team of scientists is currently working on that new model, Jackson said.

Although the Science study does not address why the previous theory might be incorrect, the scientists involved have a hypothesis, Jackson said. The velocity of the water touching a tidewater glacier face affects its melting rate: A higher velocity means a higher melt rate, just as pouring hot coffee over an ice cube melts the ice cube faster than placing it into the hot coffee. The current theory takes into account how freshwater that seeps out from the bottom of the glacier increases the water velocity as it rises to the top of ocean along the surface of the ice. However, it doesn’t take into account other drivers of ocean currents near the glacier, including wind, tide, and waves. “Those can also enhance the velocity along the ocean ice boundary, and that can also enhance melt rate,” Jackson told GlacierHub.

Collecting data from glaciers with different fjord conditions and glacier characteristics will provide the scientists with the information needed to model tidewater glacier melt as a function of the physical properties of the glacier and adjoining ocean. Since ocean conditions vary from season to season, the team is continuing to collect data at LeConte Glacier throughout the year, with the same goal of discovering how oceanic properties affect glacier melt. “One thing we’re excited about is what we present is the new method for directly measuring sub-marine melting that hopefully can be used at many other glaciers around the globe,” said Jackson.

In the mean time, estimates of sea level rise might need adjustment.

Footage of LeConte Glacier taken during the study. (Source: Dave Sutherland, University of Oregon)
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Roundup: Deaths in Alaska, Europe’s Heatwave, and Reflections on Afghanistan

Glacier instability is creating dangerous conditions for Alaska tourists

From Anchorage Daily News: “The toe of Valdez Glacier, where the bodies of three boaters were found this week, had become particularly dangerous, said a guide who had altered his own tour route due to the glacier’s increasing instability.”

Read more here.

An aerial view of Alaska’s Valdez Glacier, where the bodies of three boaters were recently found. (Source: Wikimedia Commons)

Europe’s heatwave brought unusually high melt rates

From E&E News: “The sweltering heat wave that roasted much of Europe last month has since moved north, where it’s wreaking havoc on the Greenland ice sheet. But while all eyes are currently trained on the Arctic ice, scientists are finding that Europe’s coldest places have also suffered.

According to initial findings from the Swiss Glacier Monitoring Network (GLAMOS), Swiss glaciers experienced unusually high melt rates during the last heat wave, which occurred in late July, and an earlier heat wave that struck the continent in late June.”

Read more here.

The Aletsch Glacier is Switzerland’s largest glacier. (Source: Flickr/Sam Rayner)

Reflecting on Afghanistan’s Wakhan Corridor

From Collateral Values: “On March 30th, 2014, Afghanistan declared the Wakhan Corridor as its second national park. At over 10,000 km2, the park is larger than Yellowstone National Park in the USA. It is high country, ranging from 2500 meters at its west end, to a mountain pass to China at 5000 meters in the east, and peaks of 7000 meters along its southern border. Despite its elevation, the Wakhan National Park is home to iconic wildlife species such as Marco Polo sheep and the snow leopards. It is also home to some 17,000 people. The Wakhan has had a long journey from geopolitical buffer zone to national park, a journey that is not yet complete. It became defined as a specific region during The Great Game of the nineteenth century between the two great empires of the age: Tsarist Russia, and the British Raj in India. The great powers wanted a buffer zone between them, an effort to keep their competition from accidentally spilling over into war. Neither the British, the Russians, nor the Afghan Emir could have known that in the twenty-first century, this buffer zone would come to be valued for its natural capital. While there were ceremonies to declare the park in 2014, it is not yet clear how the park will be managed. The park faces many challenges, but has great potential to preserve rare mountain habitats for the people who live there, and the world beyond its borders.”

Read more here.

The Wakhan Corridor under light snow, with a Wakhi man collecting firewood. (Source: Wikimedia Commons/Tom Hartley)

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Photo Friday: Aerial Images of Norway

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Roundup: Antarctic Species Diversity, Credit Ratings, and an Alaskan Podcast

What Happens to Species Diversity as Glaciers Melt?

Published in July 2019, a study looked at the effects of melting glaciers on seafloor species diversity in Antarctica.

Antarctic ice meeting the sea. 
Source: Tak from HK/ Creative Commons.

As glaciers melt, more sediment is released into the surrounding waters and can smother seafloor communities. As part of the same process, more icebergs are created which can scrape the bottom of the ocean, removing the top layers of sediment, known as soft sediment. 

Soft sediment contains a great deal of life and plays an important role in marine ecosystems The study explains that it is one of the “key components of energy flow through food webs” and is important “in sedimentary processes especially nutrient and carbon cycling, waste breakdown and removal.” 

The authors wrote that it was “the first study to comprehensively analyse the composition of Antarctic soft sediment metazoan communities across all size classes, from < 1 mm up to 10 cm, in two geographically distinct coves.”

The study found that “in contrast to findings from rocky substrata, there was no evidence of an effect of typical Antarctic stressors of iceberg scour and intense seasonality. As at other latitudes, organic content of the sediment was most strongly correlated with community structure, suggesting that increased sedimentation from run-off from melting glaciers may be the main climate change effect on these communities.”

Credit rating agency buys climate risk firm

A New York Times article explains the credit rating agency Moody’s purchase of Four Twenty Seven, a firm that measures climate risk: 

A helicopter dropping water over the 2018 Taylor Creek and Klondike Fires in Oregon.
Source:  Forest Service Photography/ Creative Commons

“Sudden shocks such as floods, wildfires or storms can hurt businesses and send residents fleeing, taking away the tax revenue that governments use to pay their debts. And longer-term threats — such as rising seas or higher temperatures — can make those places less desirable to live in, hurting property values and, in turn, the amount raised by taxes.

Rating agencies translate those risks, along with more traditional factors such as a government’s cash flow and debt levels, into a credit rating, which communicates to investors the odds that a government will be unable to repay its bondholders. Lower ratings generally mean that borrowers need to offer investors a higher return to account for that risk.

Following a string of deadly hurricanes and wildfires in 2017, Moody’s, along with S&P Global and Fitch Ratings, issued reports warning state and local governments that their exposure to climate risk could affect their credit ratings.”

Alaskan glacier podcast 

Alaska’s Mendenhall Glacier. 
Source: Jeff’s Canon/ Creative Commons

In a 25 minute podcast, Manasseh Franklin describes her experience following the water from a glacier in Alaska to the sea. She “wanted to make the melting of glaciers more real to people through her writing. So on an Alaskan rafting trip, she followed water to its source.”

Read More on GlacierHub:

What Moody’s Recent Acquisition Means for Assessing the Costs of the Climate Crisis

Rob Wallace Installed to Post in Department of the Interior

Dispatches from the Cryosphere: Intimate Encounters with the Intricate and Disappearing Ice of Everest Base Camp

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The Accumulation Zone of Alaska’s Mendenhall Glacier Is Shrinking

Mendenhall Glacier is the most visited and photographed terminus in the Juneau Icefield region. The glacier can be seen from the suburbs of Juneau.  Its ongoing retreat from the Visitor Center and the expansion of the lake it fills is well chronicled. Here we document the rise in the snowline on the glacier that indicates increased melting and reduced mass balance that has driven the retreat. The change in snowline from 1984-2018 and the associated retreat are documented. The snowline as July begins in 2019 is already in the end of summer range.

Mendenhall Lake did not exist until after 1910. In 1948 it was 2.2 kilometers across, and by 1984 the lake was 2.7 km across.  Boyce et al (2007) note the glacier had two periods of rapid retreat: one in the 1940’s and the second beginning in the 1990’s, both of which were enhanced by buoyancy-driven calving. The latter period has featured less calving, particularly in the last decade, and is a result of greater summer melting and a higher snowline by the end of the summer, which has averaged 1,250 meters since 2003 vs. 1,050 m prior to that (Pelto et al, 2016). In 2005, the base of the glacier was below the lake level for at least 500 m upglacier of the terminus (Boyce et al (2007).  This suggests the glacier is nearing the end of the calving enhanced retreat.  It is likely another lake basin would develop 0.5 km above the current terminus, where the glacier slope is quite modest.

Mendenhall Glacier in Landsat images from 1984 and 2018. Yellow arrows indicates 1984 terminus location, red arrow indicates the Suicide Basin tributary, and the purple dots indicate the snowline.

The glacier in 1984 ended at the tip of a prominent peninsula in Mendenhall Lake. The snowline is at 950 m. In 1984 with the Juneau Icefield Research Program, we completed both snowpits and crevasse stratigraphy that indicated retained snowpack at the end of summer is usually more than 2 m at 1,500-1,600 m. The red arrow indicates a tributary that joins the main glacier, where Suicide Basin currently forms. In 2014 the snowline in late August is at 1,050 m.  The terminus has retreated to a point where the lake narrows, which helps reduce calving. In 2015 the snowline is at 1,475 m. In 2017 the snowline reached 1,500 m.  There is a small lake in Suicide Basin. In September 2018 the snowline reached 1,550 m—the highest elevation the snowline has been observed to reach any year. In Suicide Basin the lake drained in early July. In 2018 Juneau Icefield Research Program snowpits indicates only 60 percent of the usual snowpack left on the upper Taku Glacier, near the divide with Mendenhall Glacier. On July 1 2019 the snowline is already as high as it was in late August of 1984.  This indicates the snowline is likely to reach near a record level again. The US Geological Survey and the National Weather Service is monitoring Suicide Basin for the drainage of this glacier melt filled lake. In 2019 the lake rapidly filled from early June until July 8—the water level increasing 40 feet. It has drained from July 8 to 16 back to it early June Level. The high melt rate has thinned the Mendenhall Glacier in the area reducing the elevation of the ice dam and hence the size of the lake in 2019 vs. 2018.

The snowline separates the accumulation zone from the ablation (melting) zone and the glacier needs to have more than 60 percent of its area in the accumulation zone. The end of summer snowline is the equilibrium line altitude where mass balance at the location is zero. With the snowline averaging 1,500 m during recent years, this leaves less than 30 percent of the glacier in the accumulation zone. This will drive continued retreat even when the glacier retreats from Mendenhall Lake. The declining mass balance is evident across the Juneau Icefield (Pelto et al 2013).  Retreat from 1984-2018 has been 1,900 m. This retreat is better known, but less than at nearby Gilkey Glacier and Field Glacier.

Mendenhall Glacier in a Landsat image from 2014. Yellow arrows indicate 1984 terminus location, and the purple dots indicate the snowline.
Mendenhall Glacier in a Landsat image from 2015. Yellow arrows indicate 1984 terminus location, and the purple dots indicate the snowline.
Mendenhall Glacier in a Landsat image from 2017. Yellow arrows indicate 1984 terminus location, and the purple dots indicate the snowline.
Mendenhall Glacier in a Landsat image from 2019. Yellow arrows indicates 1984 terminus location, and the purple dots indicate the snowline.

This article originally appeared on the American Geophysical Union blog, From a Glacier’s Perspective.

Read More on GlacierHub:

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Roundup: Expanding Glaciers, Appraising the Himalaya, and Ice Worms

Study shows a glacier is expanding

From Frontiers in Earth Science: “There is strong variation in glacier mass balances in High Mountain Asia. Particularly interesting is the fact that glaciers are in equilibrium or even gaining mass in the Karakoram and Kunlun Shan ranges, which is in sharp contrast with the negative mass balances in the rest of High Mountain Asia. To understand this difference, an in-depth understanding of the meteorological drivers of the glacier mass balance is required.”

Read the study here.

The outer domain (D1, 25 km, middle panel), with its nests. Left panel shows the 1 km domain of Shimshal catchment (D3), and right panel 1 km domain of Langtang catchment (D5). The catchment outlines are indicated by black contours and glacier outlines of GLDAS dataset (Rodell et al., 2004) by blue contours. (Source: Frontiers of Earth Science)

An appraisal of Himalayan glaciers

From Proceedings of the Indian National Science Academy: “The present review takes stock of the growth of cryospheric research in India with reference to glaciers and snow in the Himalaya, which are sensitive marker of the climate change. Overview of the snout and mass balance data indicates accentuated rate of glacier recession during the 1970’s and 1980’s, particularly in the Central and NE Himalaya. Like elsewhere on the globe, the retreating trends are consistent with the hypothesis of the global warming resulting from the increasing anthropogenic emissions of Green Houses Gasses. In contrast, the Glaciers in the Karakoram region, Indus basin, fed by mid-latitude westerlies, show marginal advancement and/or near stagnation.”

Read the study here.

A view of the Himalaya (Source: orangems/Flickr)

Ice worms

From Proceedings of the Royal Society B: “Disentangling the contemporary and historical factors underlying the spatial distributions of species is a central goal of biogeography. For species with broad distributions but little capacity to actively disperse, disconnected geographical distributions highlight the potential influence of passive, long-distance dispersal (LDD) on their evolutionary histories. However, dispersal alone cannot completely account for the biogeography of any species, and other factors—e.g. habitat suitability, life history—must also be considered. North American ice worms (Mesenchytraeus solifugus) are ice-obligate annelids that inhabit coastal glaciers from Oregon to Alaska.”

Read the study here.

An iceworm (Source: Wikimedia Commons)

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New Mountain Bike Trails Highlight Long Island’s Glacier Remnants

To Travel or Not to Travel

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Photo Friday: The Summertime Lure of the World’s Iconic Glaciers

It’s summertime in the Northern Hemisphere. And for those of us that are able, the summer months can mean time off from work and an opportunity to venture near or far on a vacation.

Glaciers lie on each of the world’s seven large landmasses, meaning, while they’re often located in relatively remote areas, one needn’t travel to the polar regions to observe the remnants of the last Ice Age—which makes them a popular vacation draw.

New Zealand has the Southern Alps. Glaciers are found in each of the seven Andean nations: Venezuela, Columbia, Ecuador, Peru, Bolivia, Chile, and Argentina. The mountains of the American West, as well as Alaska, host glaciers. And, of course, there are the alpine peaks of southern Europe and the iconic, albeit much more remote, mountains of the “Third Pole.”

A survey of photo sharing websites, such as Flickr, reveals the enduring allure of the world’s glaciers, particularly as climate change and the threat it poses to the longevity of the world’s cryosphere becomes more and more apparent.

And therein lies a paradox.

So-called last-chance tourism is driven by interest in visiting the landscapes that are vulnerable to rising temperatures and more frequent and more intense extreme weather events. Yet with greater interest in these places comes increasing threats to their sustainability, whether due to carbon-intensive airline travel or the consumer waste that results from a simple visit to the refreshment stand at a national park. A recent study even sought to quantify the amount of summer sea ice in the Arctic that melts with each metric ton of carbon emitted by an individual.

Individual consumer decisions won’t bring the world significantly closer to zero emissions as long as decisions about how energy is generated, what modes of transportation are available, and how consumer goods are produced—the largest sources of carbon pollution—remain largely in the realm of the public sector, that is society-wide.

Visiting glaciers can heighten one’s understanding of the massive forces bound up in Earth’s climate and geology, which, perhaps for many people, explains their seduction.

Here’s a view of some of the world’s popular glacier destinations through the eyes of recent visitors.

An image of Alaska’s Columbia Glacier taken on July 10, 2019. (Source: dvs/Flickr)
A view of tourists visiting Mendenhall Glacier in Alaska (Source: Mulf/Flickr)
A cruise ship passes in front of Alaska’s Hubbard Glacier. (Source: zshort1/Flickr)
A view of Switzerland’s Aletsch Glacier taken on June 8, 2019 (Source: velodenz/Flickr)
Tourists on a hike at Norway’s Nigardsbreen Glacier on June 10, 2016 (Source: clare_and_ben/Flickr)

Read More on GlacierHub:

East and South Asia Are the Largest Sources of Black Carbon Blanketing the Tibetan Plateau

Dispatch From the Cryosphere: Amid the Glaciers of Antarctica and Chile

South Asian Perspectives on News of Rapid Himalayan Glacier Melt

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Roundup: Alaska’s Heat Wave, Black Carbon in Tibet, and Artwork at The Met

Heat Wave in Alaska Results in Record Temperatures, Wildfires, and Glacial Melt

From Yereth Rosen at Reuters: “Alaska’s heat wave is driving wildfires and melting glaciers, choking the state’s biggest cities with smoke and bloating rivers with meltwater. Melting glaciers and mountain snowfields are bloating rivers and streams across a large swath of south central Alaska, the [National Weather Service] said. The melt has brought water levels to flood stage at the Yentna River northwest of Anchorage on [June 30].”

Read the full story here.

Recorded water levels at Yentna River, Alaska (Source: NOAA/National Weather Service)

Black Carbon Measured in the Northeastern Tibetan Plateau

From Science of the Total Environment: “Black carbon (BC), which consists of the strongest light-absorbing particles (LAP) in snow/ice, has been regarded as a potential factor accelerating the melting of glaciers and snow cover over the Third Pole. During the winter and summer of 2016, snow, ice and topsoil were sampled from the Laohugou basin located on the northeastern Tibetan Plateau. Concentrations of BC in Laohugou Glacier No. 12 (LG12) and snow cover in this basin.”

Read more about the research study here.

Eastern Tibetan Plateau (Source: Nicolas Marino, Flickr)

Contemporary Artwork at the Metropolitan Museum of Art Features Icelandic Artist Ragnar Kjartansson

From The Met: “As part of a new series of contemporary installations, The Met presents the world premiere of a major new work: Death Is Elsewhere (2019), a seven-channel video installation by the acclaimed Icelandic artist Ragnar Kjartansson. Provocatively rethinking the possibilities for performance and video art, Kjartansson makes work in which he simultaneously evokes Romantic clichés while using irony, nihilism, and absurdity to undermine them.”

Read the full exhibition overview here.

Contemporary art installations featuring Ragnar Kjartansson (Source: The Met)

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US Forest Service Plans to Overhaul Tourism at Mendenhall Glacier

Just a short journey from Alaska’s capital city of Juneau, Mendenhall Glacier is the state’s most popular summer tourist destination, and arguably one of the most accessible glaciers in the world. Located in Tongass National Forest, Mendenhall is one of 38 glaciers that originate from the massive 1,500 square mile Juneau Icefield. From its origin to its terminus at Mendenhall Lake, the glacier stretches some 13.6 miles

A strong tourism industry around  Alaska’s glaciers provides the state with substantial economic benefits. It also gives visitors an opportunity to witness the effects of anthropogenic  climate change. 

Beyond the pristine beauty and temperate summertime weather in Alaska, so-called “last chance tourism” is a huge motivation for visitors, who wish to marvel at immense blocks of blue and white ice as well as Mendenhall’s famous ice caves before they melt. 

Opened in 1962, the Forest Service Visitor Center at Mendenhall Glacier was the very first in the United States. “When this visitor center was built, there were 23,000 visitors per year, and now there’s over 700,000,” James King, a region director for the US Forest Service in Alaska, told the Juneau Empire.

The summer of 2019 is expected to break tourism records for Alaska as a whole, with 1.3 million visitors expected, a 16 percent increase from 2018. Visitorship is expected to continue growing by 2-4 percent per year. 

Current facilities are designed for up to 485,000 visitors per year. The growth in tourists has caused congestion, long waits, and an experience that is less than ideal for visitors to the 6,000 acre Mendenhall Glacier Recreation Area

Robin Bouse, a tourist who visited Mendenhall last month, described the overcrowdedness. “The visitor center was crowded, so crowded that I couldn’t wait to get out of there,” she told GlacierHub. “I came from a cruise ship with about 4,000 passengers aboard and there were four  similar ships in port that day.” 

At its current capacity, the visitor center can only accommodate 4,000 people at a time.  

A panoramic view of Mendenhall Glacier and the surrounding Mendenhall Lake, taken in the summer of 2006 (Source: Mike Keene).

In addition, tourist infrastructure will need to evolve to keep up with climate change. From satellite measurements taken by NASA’s Landsat 5 satellite in 1984 and Landsat 8 in 2013, Mendenhall retreated almost 4,000 feet, or three-quarters of a mile in under 20 years. Mendenhall Lake, which sits right at the terminus, has grown by roughly the same amount.

Another visitor to the glacier, Tim Denham, thought a visual representation of the glacier’s retreat over time would have been a valuable visual to add to the experience. “I think it would have been good to have big 4×4 posts with the years carved into them to show how rapidly it has receded,” he said.

By 2050, the glacier itself will no longer be visible from the huge windows that look out from the Mendenhall Glacier Visitor Center. ”The glacier ice was so beautiful and I felt fortunate to see it,” Bouse said. “It was easy to see that the glacier is retreating from the bare rocks surrounding it.”

Taken from the same perspective as above: Mendenhall Glacier in May 2019. Massive retreat in the 13 years between the two photos is apparent. The photographer, Henry Titzler, noted this day was about 86 degrees Fahrenheit, remembering summer temperatures averaging around 62 degrees during a previous visit in 1979.

From 2016 to 2018, six public meetings were held to develop a plan for revamping the Mendenhall Glacier Recreation Area and Visitor Center. The updated 50-year plan, published by the US Forest Service in February 2019 emphasizes major renovations over the next 10 years. 

The Mendenhall Glacier Master Plan aims to create a sustainable recreation experience that can adjust to variations in glacier features. King from the US Forest Service estimated the project’s price tag at around $80 million

As the glacier continues to retreat, the current viewpoints will become more strained, and visitors with a time limit––such as those who must return to their cruise ships––could subsequently be unable to attain the full experience.

“It was difficult to get up close to the glacier with the few hours I had to spend there, but the distant view was still spectacular enough,” said Bouse. 

Denham similarly noticed the marked appearance of the glacier’s retreat, noting it was “barely visible across the lake. We hiked out a half mile on the trail but we were still too far away to see much.” 

To accommodate increased glacial melt, the new plan proposes to switch from a land-based focus on hiking trails and viewing areas to a more water-based approach, complete with a commercial boat service to take people in small groups right to the terminus of Mendenhall Glacier.

There will also be a smaller mobile visitor center closer to the glacier itself. These new features will fulfill the frequently cited desire of tourists to truly be interactive with the glacier, allowing visitors to “touch the ice.”

Other parts of the proposed plan include more restrooms, a larger theater, and expanding parking availability. New walking trails will increase access to ecosystems newly exposed by the glacier’s retreat, including salmon, bears, and other wildlife. Finally, an additional visitor center will provide amenities such as food, restrooms, and directions, leaving the original building as an educational center and museum. 

Taken together, these alterations could give the visitors a more pleasant and informative stay, showing them the glacier as it is now and as it had been. And it could awaken in them a sense of the urgency of climate change as a pressing issue, whether on vacation or back at home.

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Photo Friday: Kevin Lyons Captures Alaska’s Mendenhall Glacier

Mendenhall Glacier, near Alaska’s capital city of Juneau, is one of the most visited and oft-photographed glaciers in the United States. Kevin Lyons, an Alaska-based adventurer, uses his lens to offer a fresh angle on Mendenhall. Lyons is a self-described “photography enthusiast with a passion for travel and the outdoors.”

Mendenhall Glacier is rapidly retreating due to climate change (Source: Kevin Lyons).

 

Dirt and cryoconite deposits on the ice surface inhibit the glacier’s ability to reflect solar radiation. Melt pools form on the ice surface, accelerating ablation by creating pores that allow water to penetrate the glacier.

Soot and debris cover Mendenhall’s surface (Source: Kevin Lyons).

 

Mendenhall’s retreat is well-documented, partly thanks to time lapse imagery provided by scientific cameras, like the one pictured below. The 2012 film, Chasing Ice, highlighted Mendenhall’s retreat to effect of global warming on the planet’s glaciers.

One of the research cameras installed to monitor Mendenhall’s retreat (Source: Kevin Lyons).

 

Mendenhall’s famous ice caves, pictured below, have collapsed since Lyons visited in 2014. A Frequently Asked Question on the U.S. Forest Service website addresses the rumor that ice caves exist at Mendenhall: “There have been several ice caves in past years, but the cave that appears in many recent internet photos has collapsed and disappeared. It was located along the west flank of the glacier but the ice has completely melted out of that area and no other caves are present.”

This image from within a Mendenhall ice cave was captured in 2014. This cave and others like it at Mendenhall have since collapsed due to melting (Source: Kevin Lyons).

 

An indirect benefit for visitors and residents of Juneau is Lake Mendenhall, which did not exist prior to 1930. The lake formed due to excessive melt. The tongue of the glacier is expected to retreat to the point where it no longer terminates in the lake itself. According to Lyons, when the ice surface freezes just right “the hockey games out there are epic.”

Skaters enjoy an indirect benefit of the glacier’s melt; Lake Mendenhall (Source: Kevin Lyons).

 

Read More on GlacierHub:

Inspiring Girls Expeditions: Encouraging the Next Generation of Women Scientists

What the Newest Global Glacier-Volume Estimate Means for High Mountain Asia

The New Science Editors of the Journal of Glaciology

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