April 6, 2021
I produced the model impact crater with a combination of the same granular materials I use for tectonic models and a projectile fired from a powerful air rifle (a city-safe version of Gene Shoemaker’s approach). The model crater developed a nice central peak as well as terraced margins. The darker material is quartz sand, combined with a small amount of cornmeal to produce a minor amount of cohesion between sand grains. The white material comprising the central peak is glass microbeads.
By Ned Rozell While out on a springtime snow trail, I recently saw a dozen white-winged crossbills pecking at snow on the side of the trail. When I reached the spot, I saw a yellow stain from where a team of dogs had paused. Last spring, I saw a bunch of crossbills gathered near an outhouse. They were congregated at a communal pee spot in the snow. The birds were …
March 24, 2021
As indicated in the previous post, lidar-derived imagery still needs ground-truthing to maximize its usefulness as a means of characterizing landslides and other slope failures. Last June, Ken Gillon and I visited the Rutherford County, North Carolina, landslide described below as part of our work with Appalachian Landslide Consultants, PLLC (ALC) on behalf of the North Carolina Geological Survey. This slide caught my eye in lidar hillshade imagery because it appeared to share characteristics with an active slide we had visited a few days before.
March 19, 2021
By Ned Rozell A few years ago, Link Olson wanted students in his mammalogy class to see one of the neatest little creatures in Alaska, the northern flying squirrel. He baited a few live traps with peanut butter rolled in oats and placed them in spruce trees. When he returned the next day, he found no flying squirrels. Instead, peering back at him were the beady eyes of the mice …
March 15, 2021
Sturm is a snow scientist at University of Alaska Fairbanks’ Geophysical Institute who has studied Alaska’s most common ground cover for decades. Many of his explorations are on long snowmachine traverses, undertaken about this time of year in the treeless Arctic.
March 4, 2021
The largest earthquake on the planet for the year 1900 happened somewhere near Kodiak, Alaska, on Oct. 9. Scientists know it was big, but how big? And could it happen again?
March 1, 2021
We have no constraints on the age of the slides, but they may reflect logging history in the area. The majority of these slopes were heavily and continuously logged during the past ~150 years, with logging in this area clearly occurring within the past 50 years. The slides may have developed after clear-cuts, with the rapid return of vegetation common in the region quickly making the area look less disturbed than it really is.
Massive icefields near the Canada/Alaska border feed Malaspina ice through a slot in the mountains. Freed of mountain walls, Malaspina’s ice oozes over the coastal plain like batter on a hot griddle. Near the Gulf of Alaska about 30 miles northwest of Yakutat, the glacier is — on clear days — visible from a window seat on an Alaska Airlines flight from Southeast Alaska to Anchorage. But the dirty-white blob on the cheek of Alaska is not as large as it used to be, which is why glaciologist Martin Truffer and his colleagues are studying it.
February 24, 2021
Debris flow events present a significant hazard to life and property in all parts of the Appalachians. The 1949 event that created the features shown here caused 8 fatalities and displaced a tremendous number of residents. Detailed mapping…along with analysis of detailed surface imagery, can greatly enhance understanding of where debris flows begin and where they travel. This understanding, in turn, can potentially reduce the human impact of these particularly dynamic and mobile slope failure events.
February 19, 2021
A “ghost forest” exposed as La Perouse Glacier in Southeast Alaska retreated. In the past, the glacier ran over the rainforest trees. Two people are also in the photo. Photo by Ben Gaglioti.