One Of The Largest Icebergs On Record In The Making

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.

The current location of the rift on Larsen C, as of January 19, 2017. Labels highlight significant jumps. Tip positions are derived from Landsat (USGS) and Sentinel-1 InSAR (ESA) data. Background image blends BEDMAP2 Elevation (BAS) with MODIS MOA2009 Image mosaic (NSIDC). Other data from SCAR ADD and OSM (update on graphic from Freedman, based on Project MIDAS data).

British Antarctic Survey (BAS) recently captured the following video footage of the immense crack in the Larsen C Ice Shelf:

Winter Trekking Through Yellowstone’s Thermal and Glacial Features

Cross country skiing in one of the glacial melt-water channels on the Blacktail Plateau.

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.

Rounded cobbles and boulders left behind from melt-water flow sit on the volcanic bedrock in many areas along the trail. Ski tip in the lower right for scale.
Looking back to the northwest on the Blacktail Plateau ski trail. Notice the scoop-shape of the landscape which is the result of this area being part of a glacial melt-water channel.
Calcite Springs overlook is accessible during the winter via the Tower ski trail.

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.

One of the fissure ridges along the upper Terraces trail is called White Elephant Back Springs and Terrace.

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.

Orange Spring Mound of the Upper Terraces in Mammoth Hot Springs.

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 Glacier, Glacier National Park – Hiking Through A Changing Landscape

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

A part of the Iceberg Lake Trail - note the u-shape valley sculpted by glacial processes.
A part of the Iceberg Lake Trail – note the u-shape valley sculpted by glacial processes.

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”.

Footbridge over Ptarmigan Creek - good  place for a snack break.
Footbridge over Ptarmigan Creek – good place for a snack break.
Nearing Iceberg Lake as the snow and sleet continue to fall.
Nearing Iceberg Lake as the snow and sleet continue to fall.

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.

Ah - the trail's end at Iceberg Lake!
Ah – the trail’s end at Iceberg Lake!

 

 

The Iceberg Glacier: Recession from 1940 to the Present

Comparisons of the Iceberg Glacier from 1940 to 2015. The photo on the left is a circa 1940 Hileman photo. GNP Archives; the center photo is a 8/14/2008 photo by Lisa McKeon, USGS, and the photo on the right is a 9/6/2015 photo by Debra Hanneman.
Comparisons of the Iceberg Glacier from 1940 to 2015. The photo on the left is a circa 1940 Hileman photo (GNP Archives) the center photo is a 8/14/2008 photo by Lisa McKeon, USGS, and the photo on the right is a 9/6/2015 photo by Debra Hanneman. Click on the photo to enlarge it in a new window.

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.

Trail Geology

Sheet sands interbedded with muds in Proterozoic Grinnell Formation.
Jeff Kuhn points out sheet sands interbedded with muds in Proterozoic Grinnell Formation.

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.

Rip-up clasts in Proterozoic Grinnell Formation.
Rip-up clasts in Proterozoic Grinnell Formation.

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.

Mudcracks preserved in the Proterozoic Grinnell Formation.
Mudcracks preserved in the Proterozoic Grinnell Formation.

All told, it was a hike well worth doing, even if you are not a geology enthusiast!

Ripples preserved in the Proterozoic Grinnell Formation.
Ripples preserved in the Proterozoic Grinnell Formation.

 

A Different Look At The Burgess Shale – The Stanley Glacier Burgess Shale Hike, Kootenay National Park, British Columbia, Canada

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 Valley, Kootenay National Park - the view is looking west from the upper talus slopes.
Stanley Glacier Valley, Kootenay National Park – the view is looking west from the upper talus slopes.

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.

The Cambrian rock units on the south wall of the Stanley Glacier area. The Stephen Formation is the unit that contains the Burgess Shale type fossils. The lockbox location is the hike’s end.

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.

Burgess Shale type fossil specimens are kept in a lock box behind the large rock. These specimens are the focus of an informative talk by the Kootenay National Park hike guide.
Burgess Shale type fossil specimens are kept in a lockbox behind the large rock located on the talus slope. These specimens are the focus of an informative talk by the Kootenay National Park hike guide.

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).

Talus slopes beneath the Cambrian Stephen Formation are prime areas for Burgess Shale type fossils.
Talus slopes beneath the Cambrian Stephen Formation are prime areas for Burgess Shale type fossils.

Keep in mind that this is within a Canadian National Park, so do not keep any of the fossil material. The quarry that has been worked recently in this area (the quarry was initially worked in 2008 by ROM earth scientists) is yet beyond the hike’s end point, near the southwest edge of the cirque.

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.

Tuzoia - a fossil arthropod specimen from the lockbox collection.
Tuzoia – a fossil arthropod specimen from the lockbox collection.
Sidneyia - a fossil arthropod from the lockbox collection.
Sidneyia – a fossil arthropod from the lockbox collection (this specimen is actually from Marble Canyon).
Sponge spicules - from the fossil lockbox collection.
Sponge spicules – from the fossil lockbox collection.
Haplophrentis - an enigmatic tubular fossil known as a hyolith. This fossil is from the lockbox collection.
Haplophrentis – an enigmatic tubular fossil known as a hyolith. This fossil is from the lockbox collection.
Anomolarcaris claw - from the lockbox collection.
Anomalorcaris claw – from the lockbox collection.
Feeding traces - from the talus slope near the lockbox.
Feeding traces – from the talus slope near the lockbox.

Canadian Rockies AWG Field Trip – A Summary

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.

Some of us took to the water and canoed around Moraine Lake near Lake Louise, Alberta. Moraine Lake is located within the valley known as the “Valley of the Ten Peaks” which was once featured on the Canadian twenty dollar bill.
Some of us took to the water and canoed around Moraine Lake near Lake Louise, Alberta. Moraine Lake is located within the valley known as the “Valley of the Ten Peaks” which was once featured on the Canadian twenty dollar bill.
Katherine Boggs talks to the field trip crew about area geology at a stop along the Icefields Parkway in Alberta.
Katherine Boggs talks to the field trip crew about area geology at a stop along the Icefields Parkway in Alberta.
Our intrepid field crew hikes the Athabasca Glacier, one of the six major glaciers of the Columbia Icefield.
Our intrepid field crew hikes the Athabasca Glacier, one of the six major glaciers of the Columbia Icefield.
Paul Hoffman explains features of the Neoproterozoic Old Fort Point Formation near Jasper, Alberta.
Paul Hoffman explains features of the Neoproterozoic Old Fort Point Formation near Jasper, Alberta.
Some of the field trip group took the arduous hike up to the famous Walcott Quarry that is developed within the Cambrian Burgess Shale near Field, British Columbia.
Some of the field trip group took the arduous hike up to the famous Walcott Quarry that is developed within the Cambrian Burgess Shale near Field, British Columbia.
A member of our field trip group shows us one of the Burgess Shale’s trilobites from the Walcott Quarry.
A member of our field trip group shows us one of the Burgess Shale’s trilobites while at the Walcott Quarry.
One of the trip’s frequent rainy days – but we still had fun by the Kicking Horse River at its confluence with the Columbia River, near Golden, British Columbia.
One of the trip’s frequent rainy days – but we still had fun by the Kicking Horse River at its confluence with the Columbia River, near Golden, British Columbia.
Our field trip group poses by Columbia Lake, which forms the headwaters for both the Columbia and Kootenay rivers, and lies within the enigmatic Rocky Mountain Trench near Canal Flats, British Columbia.
Our field trip group poses by Columbia Lake, which forms the headwaters for both the Columbia and Kootenay rivers, and lies within the enigmatic Rocky Mountain Trench near Canal Flats, British Columbia.
The Frank Slide was a must-stop as we drove along the Crowsnest Highway near Blairmore, Alberta. The slide happened on April 29, 1903, when about 82 million tons of limestone fell off of Turtle Mountain.
The Frank Slide was a must-stop as we drove along the Crowsnest Highway near Blairmore, Alberta. The slide happened on April 29, 1903, when about 82 million tons of limestone fell off of Turtle Mountain.
Part of our field trip group discusses Centrosaur Bone Bed 43 during our guided hike at Dinosaur Provincial Park, Alberta.
Part of our field trip group discusses Centrosaur Bone Bed 43 during our guided hike at Dinosaur Provincial Park, Alberta.

AWG 2014 Canadian Rockies Geology Field Trip Gears Up

Castle Mountain (Canadian Main Ranges) and Bow River, Banff National Park, Alberta, by Ben Rye.
Castle Mountain (Canadian Main Ranges) and Bow River, Banff National Park, Alberta, by Ben Rye.

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 27thFish 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”.

September 1st – Field, B.C. area with Burgess Shale Hike or other options such as Iceline Trail hike,Takakkaw Falls.

September 2nd  and 3rd – Revelstoke – Rocky Mountain Trench to Omineca Crystalline Belt, Roger’s Pass, Illicillewaet Glacier hike.

September 4th – Rocky Mountain Trench to Fernie – Windermere Supergroup (Rodinia breakup, turbidites discussions).

September 5thCrowsnest Pass to Dinosaur Provincial Park (Crowsnest duplexes & Lewis Thrust; Crowsnest Volcanics; Frank Slide).

September 6thDinosaur Provincial Park: hiking in the Badlands and guided tour of DPP bone beds.

September 7th – Dinosaur Provincial Park to Tyrrell Museum at Drumheller and return to Calgary.

Glacial Geology Field Tripping in the Northern Yellowstone Area

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)

Chico moraine boulders have an average cosmogenic age of 16.1 +- 1.7 10BE ka.

 

A succession of outwash terraces border the melt-water channel which is now the Chico Hot Springs road.

North Gardiner Area – Giant Ripples (45.0551 N, 110.7659 W)

Giant ripples occur on a mid-channel bar a few miles north of Gardiner, Montana.
Cosmogenic ages on the flood deposit boulders of the giant ripples average 13.4 +- 1.2 10Be ka.

Northern Yellowstone NP – Blacktail Deer Plateau (44.9577 N, 110.5652 W)

The Blacktail Plateau is capped by moraines of Deckard Flats age - 14.2 +- 10Be ka.
The Blacktail Plateau is capped by moraines of Deckard Flats age – 14.2 +- 10Be ka.

Northern Yellowstone NP – Phantom Lake Ice-Marginal Channel (44.9554 N, 110.5289 W)

The ice-marginal channel that Phantom Lake lies in was cut into volcanic bedrock during the Pinedale glacial recession. The lake is dammed on its down-stream end by a post-glacial age alluvial fan.
The ice-marginal channel that Phantom Lake lies in was cut into volcanic bedrock during the Pinedale glacial recession. The lake is dammed on its down-stream end by a post-glacial age alluvial fan.

Northern Yellowstone NP – Junction Butte Moraines (44.9128 N, 110.3854 W)

The Junction Butte moraines have an age date of 15.2 +-1.3 10Be ka. Large  boulders of Precambrian crystalline rocks and several ponds typify the morainal surface.
The Junction Butte moraines have an age date of 15.2 +-1.3 10Be ka. Large boulders of Precambrian crystalline rocks and several ponds typify the morainal surface.