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January 31, 2022
At the end of this month, Vladimir Romanovsky will retire after 30 years as a professor and permafrost scientist at the University of Alaska Fairbanks’ Geophysical Institute. This comes at a time when people — finally — no longer squint at him with a puzzled look when he mentions what he studies.
June 22, 2021
Low-displacement landslides explain unusual West Virginia landscape features visible in lidar imagery
Like so many older landslides in the Appalachians, the significance and cause of these features is unknown. Because they are so numerous and are only visible using lidar data acquired in 2016, they may represent an untapped resource of useful information about the recent history of Appalachian landscapes.
April 16, 2021
High on the broken pyramid of Iliamna Volcano, rotten rock held in place by volcano-warmed ice sometimes loses its grip. Several times over the years, rock-and-ice avalanches have blasted down Iliamna at 150 miles per hour. Left behind on the mountain’s face is a dirty, five-mile scar, in the same place as the last one.
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.
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 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 8, 2021
Glass beads the size of blueberries found by archeologists in a Brooks Range house-pit might be the first European item ever to arrive in North America, predating the arrival of Columbus by a few decades.