Scientists from the Universities of Bristol and Cambridge used a drone to video an eruption of one of Guatemala’s active stratovolcanoes, Volcan de Fuego. The volcano is part of the Central America volcano arc and is one of three large stratovolcanoes close to Guatemala’s former capital, Antigua. The drone flew 3,700 m over Volcan de Fuego to get the video footage.
I took a break from writing a paper on Tertiary volcanic tuffs in southwestern Montana a few days ago to go on our yearly steelhead fishing trip on the South Fork of the Clearwater River in Idaho. Steelhead are amazing fish in that they are ocean-going rainbow trout that spend two years in the ocean, and then swim back into Idaho rivers like the Clearwater, Snake, and Salmon. Eventually the steelhead reach these rivers’ upper stretches for their spawning grounds. On the South Fork, steelheads are considered as “B-runs”, which are a mix of both native and hatchery fish.
This year’s fishing adventure was marked by extremely high water levels. We usually fish at an area called the Hog Hole, a part of the South Fork that is armored by large boulders – and as an Idaho Fish and Game person told me – is an impressive velocity barrier to upstream fish migration. Fisherman typically occupy many large boulders that are scattered across the river at this location. That wasn’t possible during our fishing trip as the high water limited us to standing on only the rocks along the river’s banks.
The other impressive part of this annual fishing trip is that it takes place basically along the Western Idaho Suture Zone (WISZ). The WISZ, as noted by Fleck and Criss (2004)…
represents the boundary between crust overlying Proterozoic North American lithosphere and Late Paleozoic and Mesozoic intraoceanic crust accreted during Cretaceous time (Fleck and Criss, 2004).
The Digital Atlas of Idaho gives a good overview of the WISZ and accreted terrains. For the South Fork of the Clearwater, the Digital Atlas also breaks down the Idaho geological map by county, with the stretch that we fish lying in Idaho County. According to the Idaho County geological map, the Hog Hole sits on the west side of the suture, in accreted terranes that are partially covered by Tertiary Columbia River basalts (17.5 million to 6 million years in age) and intruded by Jurassic to Cretaceous (160 million to 120 million years in age) felsic plutonic rocks. Glacial sediments overlie these older rocks, particularly in the upper part of the South Fork drainage. The juxtaposing of all the varied geology does add another level of enthusiasm for the annual fishing expedition!
A very large crack is forming in the Larsen C Ice Shelf on the Antarctic Peninsula. The crack is up to 1,500 feet wide and will most likely generate one of the largest icebergs on record. Only 6.4 miles of ice are keeping the ice sheet from calving off an iceberg that is basically the size of Delaware. Researchers who have been studying the ice melt (Project MIDAS) estimate that although the exact timing of the calving event in unclear, it could occur easily within the next few months. In fact, scientists noted that the crack spread another approximately six miles during the second half of December 2016. From January 1st to January 19th, the crack expanded again, and now only 6.4 miles of unbroken ice remains. Once the calving event occurs, scientists are concerned that it will destabilize the Larsen C ice sheet to the point of its disintegration.
British Antarctic Survey (BAS) recently captured the following video footage of the immense crack in the Larsen C Ice Shelf:
Geoawesomeness got my attention today by featuring a You Tube video done by Vox folks a few months ago. The Vox video points out that basically all world maps are wrong in how projections of land masses are variously shown. Aleks Buczkowski from Geoawesomeness gave a lead-in to the Vox video in his posting on it by saying:
Projecting a round surface of the Earth on a flat surface is not an easy task. Scientists are trying to find an optimal way to do it for centuries. In fact the most common map projection that we use almost everyday in Google Maps and other mapping services, has been introduced in 1569 by Gerardus Mercator.
The video from Vox does help to explain the intricacies of map projections and is really worth watching:
Some winter days in Yellowstone National Park are so amazing with clear blue skies and sparkling snow that they just take your breathe away. Luckily enough, I just experienced several of these kinds of days which I packed full of cross country skiing, snowshoeing, and animal watching.
One of the groomed trails that held a good snow base until about early afternoon is the Blacktail Plateau Loop. The trail follows melt-water channels that are associated with “Retreat Lake”, which was formed by the Beartooth glacial ice mass blocking the lower end of the Grand Canyon of the Yellowstone during the Pleistocene.
The Tower ski trail provides access to the Grand Canyon of the Yellowstone area. A favorite stop of mine is the Calcite Springs overlook where the thermal springs lie south of the overlook, on the west side of the Yellowstone River and Pliocene/Pleistocene sediment and basalt are on the Yellowstone River’s east side.
A groomed ski trail also accesses the Upper Terraces of Mammoth Hot Springs. However, after a few days of spring-like temperatures, the snow was so melted back that I just used my snowshoes to trek through the icy slush. Some thermal features were still covered by snow and slush, but others appeared much more vibrant against the white snow/slush blanket.
Aphrodite Terraces lie a short way north of the White Elephant Back Springs:
My favorite thermal feature of the Upper Terraces is Orange Spring Mound. The spring is supported by a fissure ridge and is intermittently active. Because of its low water discharge and subsequent slow growth, it has built up a characteristic cone shape.
All in all, it was perfect wintertime fun trekking around in Yellowstone. Can’t wait to get back there when the bears come back out from hibernation!
Much of my research has been focused on Cenozoic sequence stratigraphy of continental basin-fill in southwestern Montana. This approach to the stratigraphy of continental deposits has facilitated correlation of stratigraphic units both within and among the various basins of this area. I recently gave a talk about my work in this area at Montana Tech of the University of Montana. Here’s the You Tube version of my talk:
NOAA’s SOS data center has a new earthquake data set animation for events that occurred from 2001 through 2015. The Science on a Sphere’s animation shown above is described on their web site as:
This animation shows every recorded earthquake in sequence as they occurred from January 1, 2001, through December 31, 2015, at a rate of 30 days per second. The earthquake hypocenters first appear as flashes then remain as colored circles before shrinking with time so as not to obscure subsequent earthquakes. The size of the circle represents the earthquake magnitude while the color represents its depth within the earth. At the end of the animation it will first show all quakes in this 15-year period. Next, it will show only those earthquakes greater than magnitude 6.5, the smallest earthquake size known to make a tsunami. Finally it will only show those earthquakes with magnitudes of magnitude 8.0 or larger, the “great” earthquakes most likely to pose a tsunami threat when they occur under the ocean or near a coastline and when they are shallow within the earth (less than 100 km or 60 mi. deep).
I came across a good posting on Carbon Brief that gives a succinct historical background for designating the new geological epoch, the Anthropocene, and thought I’d pass it on. As defined by the English Oxford Living Dictionaries, the Anthropocene is:
Relating to or denoting the current geological age, viewed as the period during which human activity has been the dominant influence on climate and the environment.
The Anthropocene is not a formal geologic time unit yet within the geologic time scale – that label will take awhile. But the Working Group on the Anthropocene (a part of the Subcommission on Quaternary Stratigraphy) gave their recommendation to formalize this time unit to the 35th International Geological Congress in Cape Town, South Africa on August 29, 2016, so there is some progress. The working group suggested that there are options for marking the beginning of the epoch, such as c. 1800 CE, around the beginning of the Industrial Revolution in Europe or about 1950, where the boundary
…was likely to be defined by the radioactive elements dispersed across the planet by nuclear bomb tests, although an array of other signals, including plastic pollution, soot from power stations, concrete, and even the bones left by the global proliferation of the domestic chicken were now under consideration. From The Guardian, 8/29/2016.
Anyways, it’s worth reading the posting on Carbon Brief by Sophie Yeo about the Anthropocene, and I’ve included one of the posting’s infographics below to peak a reader’s interest.
The Laramie Mountains are part of the central Rocky Mountains in southeastern Wyoming. Archean and Proterozoic rocks form the bulk of the mountain range due to late Cretaceous–early Eocene (Laramide) basement-involved uplift. Hogbacks made of Paleozoic to Mesozoic age rocks flank much of the
Precambrian cored mountain areas. But what sets the Laramie Mountains apart from the adjoining Colorado Front Range and even the western Great Plains is that upper Eocene to Miocene strata are preserved within the Laramie Mountains and on its sides as paleovalley fill. The reasons for this unusual paleovalley fill preservation can probably be tied to the Laramie Mountains being much lower in elevation than the adjoining Colorado Front Range and that they were not glaciated during the Pleistocene.
I went on a field trip a few days ago specifically to look at the Laramie Mountains Tertiary paleovalleys. It was a really good trip. Emmett Evanoff led the trip and because he’s spent so much time working in the area, he had much info and insight on the paleovalleys. What follows are a few photos from the trip: