February 17, 2020
The model shown here did not work out as planned because I shortened it too much, but the overall appearance is still cool and reflects local variations in the layer pack. In real fold-thrust belts, the local or regional variations in folding and faulting style also reflect the details of the layer sequence being folded and faulted, among many other conditions.
February 10, 2020
At Canton, North Carolina, the headwaters of Hominy Creek, a French Broad River tributary, are VERY close to capturing the Pigeon River. In human terms, this is still probably a long way off, but it is most certainly geologically “imminent.”
February 3, 2020
Back in 1830, The Catawba Iron and Coal Company got an outrageous deal on a plot of land at the foot of North Mountain in western Botetourt County, Virginia. Within about 1 square miles, coal, iron ore (oxide), and high-purity limestone could be mined, and thick layers of quartz pebble conglomerate could be quarried for much sought-after millstones.
Carly Phillips and her colleagues have been running the numbers on the acreage and CO2 emissions of Alaska forests that might be spared with more aggressive firefighting. She figured if Alaska’s firefighting budget were quadrupled, there could be a 60 percent reduction in acreage burned each year. “That’s similar to nearly 7 million cars removed from the road,” she said.
January 30, 2020
In cold, dry, subarctic air, a rocket taller than a house tilts northward, awaiting the moment when a person inside a nearby concrete building pushes a button. The ink-black Chatanika River valley will then flash white, and erupt with a clap of thunder.
January 23, 2020
By the summer of 2020, a landslide will bury a portion of the road from the Denali National Park entrance to Wonder Lake. That’s the conclusion of Zena Robert, a UAF graduate student who visited the park in summer 2019. Last summer, she did a ground survey of giant blobs of frozen hillside that sometimes ooze over the 92-mile road, which workers built from 1923 to 1938.
A basic Google search of “inversion geology” will produce a tremendous number of results, including conceptual illustrations, analog model results, and actual cross sections generated from subsurface imaging and drilling exploration.
January 13, 2020
This post centers around an oddly meandering, dry valley 800 ft above the northwest wall of the gorge. It’s not much to look at in Google Earth imagery alone, but with enhanced maps and some understanding of how river gorges spread through topography, it gives great context for different ways of thinking about gorge development.
Here are a few scribbles from my notebook on a subsample of the more than 1,000 Alaska talks and posters (at the AGUFallMeeting)…
January 6, 2020
On the road, car headlights cut through the ice fog that hangs over the road like cotton candy. Exhaust, about 250 degrees in the tailpipe, cools to minus 40 in less than 10 seconds after it comes out of the vehicle. Water-cooled that fast turns into tiny particles that make up ice fog. Cars and trucks aren’t the only things that make ice fog. Any source of water vapor will do, including people and dogs.