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:
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!
Iceberg Lake is situated in the Many Glacier area of Glacier National Park. The hike is about a 10 mile round trip and gains about 1275 feet in elevation. The trail winds through prime grizzly bear habitat, so be sure to hike with a group, make lots of noise, and carry bear spray. When I hiked the trail back in September, many returning hikers told our group about a grizzly sow and two cubs that were roaming around by Iceberg Lake. The bears actually walked by the lake shore while my group and many others were at the lake, but there were no harmful encounters. However – just this past week, in this same general area, a sow grizzly with 2 sub-adult cubs (I’m guessing that this is the same set of bears that walked by my group at Iceberg Lake) was surprised by a lone hiker and the sow grabbed and shook the hiker. The hiker used his bear spray escaped with puncture wounds to his lower leg and a hand. So – some words of caution about about hiking in bear country!
The Iceberg Lake Trail
The trailhead to Iceberg Lake is behind the cabins near the Swiftcurrent Motor Inn. The first part of the hike, about 1/4 mile, gains about 185 feet. After that initial elevation gain, the trail’s elevation gain moderates. Ptarmigan Falls is about 2.5 miles from the trailhead, and a short way above this is a footbridge that crosses Ptarmigan Creek. The rocky area near the footbridge is a great place for a snack break. Another 1/10 mile beyond the footbridge is the Iceberg Lake Trail junction. The Ptarmigan Trail continues towards the right and goes to Ptarmigan Tunnel and Ptarmigan Lake.Take the other trail branch to continue on to Iceberg Lake. A good trail hike summary for the Iceberg Lake Trail is found at the website “Hiking in Glacier”.
The popularity of the trail was clear to me when even on a rainy, sleety, and snowy day,I passed many people on the trail. My group did a leisurely hike, stopping at several places to look at the geology alongside the trail and to do a snack stop by the Ptarmigan Creek footbridge both on the way up and back. It took us about 5 hours for the round trip. That put us back just in time to have a much enjoyed dinner at the Swiftcurrent Motor Inn.
The Iceberg Glacier: Recession from 1940 to the Present
The Iceberg Glacier is shown in the above photo set beginning in 1940 (this is the photo on the left, which is a Hileman photo from the Glacier National Park Archives) and ending with the 9/6/2015 photo on the right, which I took during my hike to Iceberg Lake. In the 1940 photo, the glacier terminus is quite thick and extends into the basin. By 2015, there is not much left of the glacier. Even with a comparison between the center 2008 photo by Lisa McKeon and my 2015 photo, one can see that much more bedrock is exposed. The older photos are also posted on the US Geological Survey’s Repeat Photography Map Tour Website. For those interested in glacial recession within Glacier National Park, the Repeat Photography website is a valuable resource. The Repeat Photography project is summarized on the USGS website –
This project began in 1997 with a search of photo archives. We used many of the high quality historic photographs to select and frame repeated photographs of seventeen different glaciers. Thirteen of those glaciers have shown marked recession and some of the more intensely studied glaciers have proved to be just 1/3 of their estimated maximum size that occurred at the end of the Little Ice Age (circa 1850). In fact, only 26 named glaciers presently exist of the 150 glaciers present in 1850.
Much of the Iceberg Lake Trail winds through the Grinnell Formation, which is a Proterozoic geologic unit within the Belt Supergroup. As Callan Bentley has succintly said of the Belt Supergroup rocks in Glacier National Park:
The rocks exposed firstly from the top down are old sedimentary rocks of the Belt Supergroup. It is called “Belt” after Belt, Montana, and “supergroup” because it is immense. These rocks were deposited in a Mesoproteozoic (1.6-1.2 Ga) sea basin, and show little to no metamorphism despite their age.
I was lucky to be hiking with Jeff Kuhn from Helena, Montana, who has done much work with Belt Supergroup rocks in the Glacier Park to Whitefish Range areas. Jeff stopped us at several locations along the trail to look more closely at features within the Grinnell Formation. In general, the Grinnell Formation consists of sandstone and argillite and is approximately 1740-2590 feet thick. It has a deep brick-red color owing to its contained hematite and because it was deposited in a shallow oxygen-rich environment. Sedimentary features that are consistent with the shallow water depositional interpretation include mudstone rip-up clasts, mudcracks, and ripple marks.
All told, it was a hike well worth doing, even if you are not a geology enthusiast!
The Middle Cambrian Burgess Shale and its contained fossils are legendary to earth scientists. These fossils are by far the best record of Cambrian animal fossils. The importance of the Burgess Shale fossils is also linked to their excellent preservation. The fossils include many soft bodied animals in addition to those with hard parts – an extremely rare occurrence for fossil assemblages.
I finally hiked to the Walcott Quarry on Fossil Ridge near Field, B.C., last year, just to better understand the context of the Burgess Shale. It was well worth the effort (it is a long, and as other hikers phrased it – a gut-busting hike). Before my Walcott Quarry hike, I’d read that Kootenay National Park just started hosting hikes to Burgess Shale type faunas (BST) in the Stanley Glacier area. It only took a good dinner and a beer after the Walcott Quarry hike to decide that I’d do the Stanley Glacier Burgess Shale hike.
Stanley Glacier BST fossils (approximately 505 million years in age) are about 40 km southeast of the Field, B.C. (Yoho National Park) locales. Recent work in both the Marble Canyon and the Stanley Glacier areas of Kootenay National Park yielded noteworthy additions to understanding the BST fossils and their depositional environments. BST fossils found in the Marble Canyon area include 25 new species of organisms; 8 new species are now recorded for the Stanley Glacier BST fossils. Of more interest to me (being a sedimentologist), is that the depositional environment in the Kootenay National Park area differs from that of the Field, B.C. area. Although the Burgess Shale fossils are found within the Stephen Formation in both areas, there is a marked difference in this rock unit from one area to the other area. Around Field, B.C., the Stephen Formation is the “thick or basinal” (about 276 to 370 meters thick) Stephen and it resulted from deposition at the base of the older Cathedral Formation Escarpment (a submarine cliff) via turbidity flows. In the Stanley Glacier area, the Stephen Formation is relatively “thin” (about 33 meters thick) and is probably the result of deposition at the distal edge of a marine platform (Caron and others, 2010; Gaines, 2011). The stratigraphic placement of the Burgess Shale rock units also differs from the Field, B.C. area to the Stanley Glacier area. Based upon the presence certain trilobites and stratigraphic evidence (Caron and others, 2010), the “thin” Stephen Formation at Stanley Glacier is stratigraphically above the Field, B.C. Burgess Shale localities.
With that small bit of Burgess Shale background, I’ll get back to the actual hike up the Stanley Glacier valley to the Stephen Formation talus slopes and outcrop. The hike is hosted by Kootenay National Park and is about 10 km for the round trip. The elevation gain is about 450 meters. The first part of the hike is through glacial material and a fire-swept lodgepole pine forest. Forest fires burned through this area most recently in 1968 and in 2003. Luckily for paleontologists, the fire bared many slopes and definitely helped in locating BST fossil beds. A little more than halfway through the hike, one breaks out of the trees onto the talus slopes of Stanley Glacier’s valley. The hike continues over the talus slope to a very large boulder. Several BST fossil specimens are locked in a box kept behind this boulder. Our guide gives an informative talk about the lockbox fossils and we have much time to pick around the talus slope for more fossils.
In 1989, an expedition party from the Royal Ontario Museum (ROM) located fossils from Stephen Formation talus in this area (Rigby and Collins, 2004: Sponges of the Middle Cambrian Burgess Shale and Stephen Formations, British Columbia; Royal Ontario Museum Contributions in Science 1: 1–155.). Caron and others (2010) also document that some of their fossil assemblage material came from the talus slope, so it’s worth some time to look around (Caron and others, 2010 GSA Data Repository).
Stanley Glacier BST shelly fauna includes characteristic Cambrian taxa such as hyolithids, brachiopods, and trilobites. Soft-bodied BST creatures such as the necktobenthic or nektonic arthropods and proto-arthropods Stanleycaris hirpex n. gen., n. sp., Tuzoia retifera, and Sidneyia inexpectans also are part of the BST fauna. Trace fossils are plentiful on some bedding surfaces. These include trails, shallow burrows, and arthropod trackways.
The AWG 2014 Canadian Rockies Field Trip took place from August 28 to September 7, 2014, with a Calgary-area geology pre-trip for early arrivals on August 27. The main part of the field trip commenced with a mid-morning departure on the 28th from Calgary, and we all headed west along Canada Highway 1 to Lake Louise. After spending two days in the Lake Louise area, we drove north to the Columbia Icefields. A few of us continued further north the next day, on an side trip to Jasper. From the Icefields we toured south to Field, British Columbia, over to Revelstoke, and ended our British Columbia time in Fernie. We then drove east, back into Alberta, and spent time at Dinosaur Provincial Park near Brooks and at the Royal Tyrrell Museum of Palaeontology in Drumheller. The trip ended with our group once more back in Calgary, Alberta.
There were 22 people as full-time field-trippers and two more people on the trip during the Icefields to Field, B.C. part of the trip. Two of the full-time trip participants were students and one of the additional, part-time trip participants, was a student. All of the students on the field trip are from Mount Royal University in Calgary and are students of our field trip leader, Katherine Boggs. Paul Hoffman and Mindy Brugman also helped out for a day or so during the trip. Marcia Knadle and Debra Hanneman did the trip budget and logistics. We had a great field trip guidebook, thanks largely to Katherine Boggs’ efforts. The field trip guidebook, “Tectonics, Climate Change, and Evolution: Southern Canadian Cordillera” will be on sale at the AWG online store soon.
The Association for Women Geoscientists’ 2014 Canadian Rockies geology field trip is fast approaching. The trip starts and ends in Calgary, and runs from August 28th through September 7th, with pre-trip hikes around the Calgary area on August 27th. Because the trip geology will be so spectacular and many people wanted to go, but just did not have the available time to do so, we decided that we will do blog postings during the trip whenever we have access to wifi (which should be most of the field trip nights). And – if anyone is really interested in the trip after following our travels, the field guidebook will be on sale at the AWG Online store after the trip.
To better follow our postings, I thought it would be helpful to give a brief run-down of the trip itinerary so that everyone knows what to expect for our travels:
August 27th – Fish Creek Park in Calgary – looking at the 2005 and 2013 Calgary flood features and constraining the boundary between the Laurentian and Cordilleran Ice Sheets.
August 28th and 29th – Trans-Canada Highway to Lake Louise for classic transect through Foothills to Main Ranges of Foreland Fold and Thrust Belt.
August 30th and August 31st – Icefields Parkway: Peyto Lake, Saskatchewan Glacier, Athabasca Glacier stops just to name a few. We also will have Paul Hoffman with us, so we will have good discussions on topics like “snowball earth”.
Living near Yellowstone National Park has its advantages – and the best of these is being easily able to go on field trips to the Park area. A field trip opportunity came up last week when the Rocky Mountain section of the Geological Society of America came to Bozeman, Montana, for its annual meeting. One of the meeting field trips was the “Glacial and Quaternary geology of the northern Yellowstone area, Montana and Wyoming”. The trip was led by Ken Pierce, Joe Licciardi, Teresa Krause, and Cathy Whitlock. Having spent much time in the Yellowstone area, I was ecstatic about going along to find out about recent geological work. I won’t elaborate on the specifics of the trip, but for those interested in more than the photos posted below, the field trip guide is available in The Geological Society of America Field Guide 37, 2014, p. 189-203. It’s worth a read!
A few of the stops on the trip:
Paradise Valley – Chico Moraines and Chico Outwash (45.3402 N, 110.6967 W)
North Gardiner Area – Giant Ripples (45.0551 N, 110.7659 W)