Roundup: A Tlingit Song, Glacier Theory, and Rock Glacier Classification

Tlingit Song Recalls Glacier Bay and Time Gone By

A recent paper describes a song from 120 years ago that a Huna Tlingit woman named Mary Sheakley first sang after an encounter with wolves in Glacier Bay Alaska. Just as remarkable is the spontaneous recollection of it decades later by her younger clan sister after being nearly lost to time.

Read the story by Grennan Milliken on GlacierHub here.

Amy Marvin performing Mary Sheakley’s song in 1996. (Credit: University of Southeast Alaska)

An 1852 Visit to an Opponent of Glacier Theory

After a promising start to his earth sciences career, Louis-Albert Necker, grandson of renowned geologist and Alpine explorer Horace-Bénédict de Saussure, abandoned his hometown of Geneva, publishing nothing further and spending the last twenty years of his life on the Scottish Isle of Skye. At the time he disagreed that glaciers were responsible for the deposition of erratics, instead preferring deluge theory as responsible for their movement. From the journal Earth Sciences History:

“Necker conceded that glaciers had once been more extensive but remained unconvinced by this explanation for the widespread movement of rocks, considering the evidence insufficient. His preferred explanation, catastrophic floods following the melting of glacier barriers that formerly retained mountain lakes, was in line with his grandfather’s theory.”

Read more in “A Visit To Louis-Albert Necker On The Isle Of Skye, 1852.”

Necker is best remembered for the Necker cube (on the left), impossible cube on the right (Source: WikiCommons).

A Study to Classify Rock Glaciers

An effort to classify rock glaciers into binary status, intact vs relict, resulted in the inventory of 235 rock glaciers, which can be used to estimate quantity of frozen material within a rock glacier. The study, focused in South Tyrol, Eastern Italian Alps, was published in the journal Science Direct. From the abstract:

“Ice presence in rock glaciers is a topic that is likely to gain importance in the future due to the expected decrease in water supply from glaciers and the increase of mass movements originating in periglacial areas. This makes it important to have at ones disposal inventories with complete information on the state of rock glaciers. This study presents a method to overcome incomplete information on the status of rock glaciers (i.e. intact vs. relict) recorded in regional scale inventories.”

Read the full study here.

Intact and relict tongue-shaped rock glaciers located in Zay Valley – South Tyrol (Source: Kofler et al).

Read More on GlacierHub:

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Russian Navy Confirms Emergence of Five New Islands in the Arctic Ocean

Video of the Week: Debris Fall Caught on Camera at Ganja La

New Mountain Bike Trails Highlight Long Island’s Glacier Remnants

In the hamlet of North Hempstead, New York, a new mountain bike path is being cut in the footprint of an abandoned sand mine. A local non-profit, the Concerned Long Island Mountain Bicyclists, or CLIMB, is creating up to seven miles of paths, creatively integrating glacier-formed features into a trail network, and cleaning up decades of accumulated industrial waste in the process.

During the last glacial maximum, about 18,000 thousand years ago, the Laurentide ice sheet covered much of North America including present day New York City. Long Island, which extends 118 miles into the Atlantic Ocean eastward from Manhattan, was created by two glacial advances, the Illinoisian and the Wisconsin glaciations. Long Island was the eastern terminus of a massive glacial moraine, which spanned the entire North American continent. 

Exit glaciers from the Laurentide ice sheet formed the greater New York region’s landscape. The glaciers pushed sand and gravel into piles, or moraines, which, thousands of years later, provided a bountiful sand deposit from which to mine.   

JB Bennington is a professor of geology at Hofstra University on Long Island, whose research activities include the glacial history and glacial geomorphology of Long Island. “There are very thick deposits of well-sorted glacial outwash sands that built up at the margin of the ice and in many cases were subsequently ice-thrusted and piled up by readvances of the glacier,” Bennington told GlacierHub. “These moraine deposits are thick and well above sea level, which makes mining a lot easier because you don’t have to pump groundwater out of the hole you create.”

Much of New York City’s present day skyline is owed to its glacial history.

The bygone Port Washington sand mine is located less than 18 miles from Manhattan, whose skyscrapers, bridges, and sidewalks were built from the extracted sand and gravel. The materials removed from the ground in Port Washington—140 million tons of it—made up an estimated 90 percent of the concrete used to construct the city during the mine’s operation. An estimated 50 barges of sand and gravel were shipped daily to Manhattan between the 1880’s and 1989, when the mine closed.   

George Williams is the former chairman of the North Hempstead Historic Landmark Preservation Commission. Sand mining was “such a vital industry, so important to the community, and nothing remains,” Williams noted to The New York Times in 2008. “It was almost like it was wiped off the face of the earth.”

Wiped off the face of the earth—except for the debris that was left behind.

Thirty years after the mine ceased operations, piles of ravaged earth and industrial equipment remain. While glacier-deposited resources first drew the extractive mining industry to North Hempstead 140 years ago, today a glacier-inspired mountain bicycle trail is cleaning up after them.

CLIMB, which was founded in 1990, is headed by lifelong Long Island resident Michael Vitti. His group has built and maintains 175 miles of sustainable cycling trails from Manhattan to Montauk, at the eastern end of the island.

A sustainable trail resists the forces of use and erosion, minimally impacts the natural ecosystem, and creates a cadre of people who care for the trail. Vitti’s method aims to endear the community to the area through enjoyment of the outdoors. “They’ll come to love the trails,” he told GlacierHub, “and they’ll come to love and steward the area and clean it up and it’ll become much better.”

Vitti and his volunteers, braving poison ivy, mosquitoes, and deer ticks, have painstakingly mapped and marked the 200-acre plot. “Most people come once and they don’t come back because of the poison ivy,” said Vitti, who is this author’s uncle. “In urban areas where there are lots of greenhouse gases, poison ivy grows mutantly fast. And tall. And big.” The poison ivy immunity of several CLIMB volunteers makes trail construction by hand tool possible. Though it is slow going, 20-30 hours of labor per mile just to flag a viable route for cycling. They’ve done so while complying with the state’s stringent Department of Environmental Conservation requirements, which limits the removal of plant species and constrains the method of trail construction.

They carefully marked a path through the dense vegetation, much of it invasive plant species, without removing a single tree. Routes follow the natural contour of the land and soil disturbance is kept to a bare minimum. Only hand tools are used to blaze the trail. Even the bridges they’ll construct will be fabricated off site to keep sawdust out of the area.

They have removed, however, several tons of industrial detritus.

Braided steel cables and rusted 55-gallon drums, car parts, hot water heaters, truck tires, railcar axles, are among the debris. “Everywhere you look there’s garbage,” Vitti told GlacierHub.

Doing something about the fouled site has been on his mind for a long time.

In 1998, Vitti submitted a request to the town of North Hempstead to repurpose the neglected land for community enjoyment. Every few years Vitti inquired about his request. It was not until 2018, however, that he found a receptive ear in the town through councilwoman Dina DeGiorgio and partnered with local environmental action non-profit PWGreen.

Judi Bosworth is the town supervisor of North Hempstead and a champion of the project. “The Town is looking forward to the opening of the CLIMB bike trail,” she told GlacierHub. “We are so impressed with the quality of work and commitment by the members of CLIMB. The trail system is certainly going to be a wonderful addition to the recreational offerings here in the Town of North Hempstead.”

At the time of writing, Vitti’s group has completed 1.65 miles of the planned five to seven-mile trail network, which he anticipates completing by the end of the summer. The new trail contains many glacial features including thousands of erratics, bluffs of white cretaceous clay, and black clay. Some trails ramp into hump-shaped glacial erratics that allow advanced cyclists to ride up and over. A meander in the path was going to take riders past a rare hoodoo—a ten-story sedimentary spire eroded over the millennia. The impressive natural feature, and the planned path around its perimeter, however, is threatened by a grading project to prevent sediment from running off into a nearby golf course.

While some glacier-created topographical features remain, many of the hills on the trail are mining spoils—giant piles of discarded earth material from a century of extracting sand.

“When we’re digging into it, it’s like digging into cookie dough ice cream,” said Vitti of the challenge of building in the sand and clay-mounded ruins of the mine.

Two other Long Island mountain biking trails bear glacial names. CLIMB  created “Glacier 8,” which has one of the best views and terrain, according to Vitti. The trail runs along the edge of the Ronkonkoma glacial moraine, a feature of the Wisconsin glaciation 85,000-11,000 years ago. Another CLIMB  trail, “Glacier Ridge” in Farmingville, located farther East on the same moraine, is one of Long Island’s most popular mountain biking routes and contains many glacial features.

Most New Yorkers are unaware “that they are living in the middle of a glacial event park,” Joerg Schaefer, a researcher at the Lamont-Doherty Earth Observatory at Columbia University, told The New York Times in 2005.  

It might just take a bike trail to allow people to realize it.