Less than one mile upslope from Alaska’s Dalton Highway, there are 23 frozen debris lobes looming.
Frozen debris lobes (FDLs) are something like a cross between a landslide and a glacier. They’re silty sand and gravel, stones, icy frozen soil as well as liquid water kept from freezing by the intense pressure of the slow-motion push downhill.
I’m sure you’ll enjoy the scientists’ intro. better:
Today I set out for the first leg of a trip. I’ll meet some of the researchers studying FDLs, and join them at their Dalton Highway research site. While FrontierScientists director Liz O’Connell is an experienced videographer and often joins scientists in the field to film, I mainly get interviews. I’m looking forward to the in-the-flesh experience! This will be real Arctic field science, hordes of mosquitoes and all.
Close scientific attention to this phenomenon is fairly new – how exciting for the scientists, to get to learn so much about a mystery few have even heard of.
In preparation (and the hopes of having smarter questions on hand) I’m bulking up on FDL knowledge… just now I’m reading this: ‘Rapid movement of frozen debris-lobes: implications for permafrost degradation and slope instability in the south-central Brooks Range, Alaska‘, by R.P. Daanen, G. Grosse, M.M. Darrow, T.D. Hamilton, and B.M. Jones. It’s one of the articles linked from the researcher’s project site: http://fdlalaska.org/info.html.
“Currently, some frozen debris-lobes exceed 100 m in width, 20 m in height and 1000 m in length. Our results indicate that frozen debris-lobes have responded to climate change by becoming increasingly active during the last decades, resulting in rapid downslope movement.” ~Daanen, Grosse, Darrow, Hamilton, and Jones (2012)
The Dalton Highway is important; it’s the only link between the road systems of interior Alaska and the North Slope, home of operational Alaskan oil fields (as well as lots and lots of Arctic science spots, but I digress). Parallel to the highway, oil flows through the Trans Alaska Pipeline system while trucks cart the oil on the highway itself.
You can imagine, then, why the inexorable slide of massive FDLs toward the road and pipeline, no matter how slow, isn’t a warming sight. The sheared and toppled trees probably agree.
FDL-A, the lobe prominently featured in the video above, is less than 200 feet from the highway. Between 1955 and 2008 it moved an average of 0.4 inches per day (info. gleaned from archived aerial photos) but the scientists’ 2012 field investigations showed the rate of movement increased to 1 inch per day.
It sounds remarkable right? As in, something to be remarked on. Especially by Alaskan residents. Yet I imagine it’s little known.
This seems like one of those things you learn, and then think you ought to have known about. Like when someone asks ‘Did you vote yesterday?’
It’s like the day I heard my old middle school was settling (and crookedly) by inches into the ground every year because they’d built on wetlands. Or – another wetland tale of woe – noticing that a local wetland where beautiful Sandhill cranes used to build impressive nests in spindly tall trees had been turned into a new residential district of too-large houses; the sign on the neighborhood’s neatly mortared brick entryway read ‘The Conservancy’.
This is like permafrost degrading in rising temperatures, releasing potentially vast quantities methane and carbon dioxide, decaying the ground under coastal communities and sending them into the sea, tilting houses and undermining roads. It’s remarkable.
I love the rap. It’s brave, it’s catchy. It’s getting the word out. They’re serving us as scientists and science communicators alike. And soon I get to meet them. (:
More science after the break.
Frontier Scientists: presenting scientific discovery in the Arctic and beyond
Frozen Debris Lobes project
- ‘Rapid movement of frozen debris-lobes: implications for permafrost degradation and slope instability in the south-central Brooks Range, Alaska’ R.P. Daanen, G. Grosse, M.M. Darrow, T.D. Hamilton, and B.M. Jones, Natural Hazards and Earth System Sciences, 12, 1521-1537, 2012 doi:10.5194/nhess-12-1521-2012