February 24 2015— Slow landslides in permafrost slide downhill on mountain slopes in the Brooks Range of Alaska. These massive frozen debris lobes are geohazards. They pose a potential threat to the Dalton Highway, Alaska’s lone road to the North Slope. There are 23 identified frozen debris lobes situated less than one mile uphill from […]
Tag: geology
Many angles to decode frozen debris lobes
“Something chewed on the casing,” Margaret Darrow explained. “Probably a bear.” Blue chips were scattered from the cracked ABS pipe. Inside the casings that protect the holes drilled in and around frozen debris lobe -A there’s non-toxic propylene glycol. Propylene glycol, this brand a clear greenish liquid, prevents freezing – helpful for scientific instruments – […]
Effective stress and FDL science
“It’s a very dynamic slope,” Margaret Darrow said, standing in front of frozen debris lobe -A. FDL-A is a slow landslide; among the frozen debris lobes documented it’s the closest to the Dalton Highway and the Trans-Alaska Pipeline. Although the lobes likely began their life as debris left over when Pleistocene glaciers disappeared 10 to […]
Temperamental machinery and FDL science
When the machinery mounted to the man-height pole announced “RTK initialized,” the scientists gave a cheer. It was late afternoon and the morning’s downpour had finally cleared. They were gathered in a sunny spot discussing what was still on the agenda for the day when the rover – the pole and its paramount differential GPS […]
Measuring and modeling geothermal resources at Pilgrim Hot Springs
There’s a place where the perennially frozen ground of the Alaskan tundra is interrupted by 2 square miles [~ 5 km² ] of thawed soil. There, cottonwoods and thick brush grow among lazily meandering waterways. The Pilgrim Hot Springs are a pleasant symptom of the geothermal heat which warms the earth deep beneath Alaska’s Seward […]
A forest revealed under glacial ice
Laura Nielsen for Frontier Scientists – Alaska’s Mendenhall Glacier is shrinking, and its retreating ice has bared the remains of an ancient forest. Preserved stumps and trunks, many still rooted and even bearing bark, sit in a gravelly mix of stone churned up by the glacier. The trees are being exposed to open air for […]
Flowing tongues of rock, ice and dirt
Ned Rozell for UAFGI – A few years ago, Ronald Daanen was driving north of Coldfoot on the Dalton Highway, looking for drunken trees. He pulled over when he saw some tipsy spruce on a hillside. The University of Alaska Fairbanks scientist thought the tilted trees would be a classic sign of thawing permafrost, ground […]
Alaska volcano observers kick serious ash
With active volcanoes as close as 80 miles of Anchorage city limits, Alaskans are grateful for the professional volcano watchers who work in a nondescript building on the campus of Alaska Pacific University, topped with a massive array of tracking and communication instruments. “The August 18, 1992 Spurr eruption, sent an ash cloud here that […]
Old age: it’s all in your mind when it comes to geologic time
It’s just a matter of time before one of the volcanoes in the chain that lines Cook Inlet erupts. But time in geologic terms is a bit like the federal deficit; so vast in scope it’s hard to comprehend. The Cook Inlet volcanoes of south central Alaska are practically babies when it comes to earth […]