Qikiqtaryuk: the Big Island by Sam Cornish

Qikiqtaryuk - the transliterated name in Siglitun Dialect of Inuvialuktun for Canada’s westernmost Arctic island. It means: the Big Island. But the Big Island is getting smaller.

 The northwestern corner of Qikitaryuk, sunlit sea ice beyond

The northwestern corner of Qikitaryuk, sunlit sea ice beyond

 Large thaw slumps work their way slowly back into the interior of the island

Large thaw slumps work their way slowly back into the interior of the island

The narrative of this island is unusual. It was borne from the advance of ice, and is ultimately being destroyed by loss of ice. It has a human story - which in this post I’ll give background to with a rough intro to the changing people of the Arctic through the last few millennia. I’ll explain why the shape of the seafloor near to this island made it a great place to hunt - and live. I’ll also talk about what happened when whalemen from San Francisco started to overwinter at the island over a hundred years ago. All photos are my own, taken when I visited the island in July 2015. This blog post is informed by the excellent book, Herschel Island - Qikiqtaryuk, edited by Chris Burn. The book covers everything from climate to culture and answers the implicit request of Danny Gordon who, along with his family before him has seen scientists and archeologists come to Herschel for decades: ‘I am supportive of research as long as it is properly explained’. Danny’s sentiment is important not just in the context of conducting research on lands used by First Nations or indigenous communities, but also as a wider message to the world of research science, in which the norm is to only explain research to other scientists.

 A bear skin dries in the summer air

A bear skin dries in the summer air

The origins of the island take us back to the mountains I looked at in the last post. Between 200 - 100 million years ago, rifting of the Earth’s crust north of where the British Mountains now lie opened up the Beaufort and Mackenzie sedimentary basins. As the British mountains underwent a new period of construction c. 75 Myr ago, rivers such as the Firth incised into the mountain belt and carried sediment downstream, to be deposited in these basins. As more and more sediment piled up on the continental slope of NW Canada, sediments nearer the bottom of the pile cemented into rock under pressure. Now, the top of the sediment pile - deposited and reworked by rivers, glaciers and the sea - is unconsolidated to a depth of approximately 1 km, and several kilometres of older cemented sediments lie below that. This is basically a big recycling process; the rocks that constituted the mountains - the fragments of which are now creating these new rocks - had themselves been formed from the tiny fragments of mountains washed into a shallow sea and then uplifted by tectonic convergence. And some time in the geological future the new rocks may be crunched into mountains.

 The Firth spreads into a braided river upon reaching the coastal slope, where it continues to deposit sediment from the British Mountains, as it has been doing for tens of millions of years

The Firth spreads into a braided river upon reaching the coastal slope, where it continues to deposit sediment from the British Mountains, as it has been doing for tens of millions of years

At some time during the last glacial period, all traces of which had ended by 10,000 years ago, an ice sheet advancing along the northern coast of NW Canada gouged deep into this unconsolidated sediment in the coastal plain. Qikiqtaryuk was made as a sheet of sediments several hundred metres was shunted along a plane of failure up and out onto the surrounding land. The close match in size between the island and a corresponding basin (Herschel Basin) directly to its east is evidence for this genesis, as is the deformed glacier ice that can be seen exposed in the coastal bluffs on Qikiqtaryuk. Furthermore, a special explanation is required for significant topography that is formed solely of unconsolidated material, which is made of sediment that pools in basins - it does not collect into high plateaux that project above the surrounding surfaces.

As the climate warmed into the Holocene epoch - the time of relatively stable warm temperatures 10,000 yrs ago to the present - the sea level rose, and continues to rise, currently c. 100 m higher than at the glacial peak. When humans first visited Qikiqtaryuk, it would very likely have still been a peninsula.

 Professor Chris Burn explains the existence of sand and gravel bars between Qikiqtaryuk and the mainland on the approach to the island

Professor Chris Burn explains the existence of sand and gravel bars between Qikiqtaryuk and the mainland on the approach to the island

The first known inhabitants of Arctic Canada and Greenland are often lumped into a broad cultural entity: the Arctic Small Tool tradition. This culture developed in parts of western Alaska around 4,500 years ago and used microblade technology - small blades made from rocks like chert or obsidian which break into sharp flakes. Microblades helped to improve hunting success for these people who often had to move significant distances when faced with food scarcity. Interestingly, the bow-and-arrow technology of the Arctic Small Tool tradition in Arctic Canada was not used by the next major group to dominate, the Dorset Culture, who instead primarily hunted seals using triangular end-blades hafted onto harpoons. The Dorset Culture, inscribed in Inuit legend as being gentle giants with shamanistic traditions and otherworldly carvings of Polar Bears, were almost entirely extinct by 1500 AD, and rapidly replaced by the ancestors of the modern Inuit and Inuvialuit, the Thule. The Thule achieved a rapid spread across Arctic Canada to Greenland in the centuries 1100-1400 AD, and skin-covered boats entered the Arctic archaeological record for the first time. The Thule are frequently characterised as intelligent toolmakers who were using iron before European contact. Unlike the Dorset Culture, there is little evidence for an emphasis on the supernatural within the Classic Thule.

Qikiqtaryuk was probably semi-permanently occupied since the advance of the Thule around 1200 AD; the longest record of inhabitation by the Inuvialuit and their ancestors in the Western Arctic. Multiple archeological sites on the island reveal how these people lived and hunted. There is, of course, so much to the history of these people - language, relations, behaviour - that I’m neglecting here.

 Avadlek Spit - archeological study has uncovered a community from 1500 AD who constructed a home on this strip of land

Avadlek Spit - archeological study has uncovered a community from 1500 AD who constructed a home on this strip of land

It is the special physical and oceanographic setting of Qikiqtaryuk that has made it a desirable place to live, the Big Island.

Qikiqtaryuk lies next to the junction of two large portions of continental shelf to the east and west. At the juncture is the Mackenzie Trough, a submarine valley running down to the ocean depths. During the ice-free season, easterly winds across this part of the Arctic coast dominate. Due to the fact that we are on a spinning planet, the surface water that gains momentum from these winds actually moves to the right-hand side of the winds in the northern hemisphere, and to the left in the southern hemisphere. This is called the Coriolis Effect. As the surface water moves to the right of the easterly winds, away from the coast, water must replace it from below. The Mackenzie Trough provides a conduit for these waters to come from the nutrient-rich deep ocean. This influx of nutrients leads to plentiful growth of tiny plants in the surface waters called phytoplankton, which are then fed on by tiny animals called zooplankton. The upwelling current sweeps these zooplankton onto the shelf in an appetising brew for the Arctic’s largest mammal, the Bowhead Whale. The Bowhead has the largest mouth of any animal on Earth, and uses its enormous head to break through sea-ice up to 60 cm thick for air. Seals - and therefore polar bear - also have historically thrived at Qikiqtaryuk.

The Mackenzie River discharges 600 cubic km of freshwater each year into the Arctic Ocean. Qikiqtaryuk lies close to the Mackenzie Delta, and receives a brackish river plume that in the summer can be as warm as 16 C. The river is fed by two major lakes - the Great Slave and Great Bear lakes - meaning that in the winter, discharge continues, and freshwater moves out beneath the ice-covered ocean. Relatively buoyant due to its low salinity, it spreads out at the top of the water column below the land-fast sea ice. At the juncture between land-fast and open-water sea ice, collision of the two domains results in a jumbled pile of ice, protruding above and below the surface. This subsurface rubble acts as a barrier to the spread of freshwater, and the river plume slowly accumulates into a freshwater lake below the ice. Known as Lake Herlinveaux, by the end of winter it is supposedly the 20th largest lake in the world.

The relatively fresh water around Qikiqtaryuk provides a migration channel for freshwater fish swimming between the Alaskan Colville River to the East and the Mackenzie to the West. Fish such as the Arctic Cisco and Dolly Varden Char use the shallow channel of open water between Qikiqtaryuk and the mainland, known as Workboat Passage. This patch of water is sheltered by gravel bars at either end, and is a habitat for birds and sea-ducks. The gravel and sand bars are all that remain of an earlier shoreline, the more easily eroded land behind the gravel beaches degraded and washed away by rising sea levels.

Five-hundred year old remains from a house on the Avadlek Spit, which projects into Workboat Passage, indicate its inhabitants hunted perhaps entirely fish and birds, and stored food for the winter in a log-lined cache. Such a low reliance on seal is thought to be unique for a coastal site in the Western Arctic.

 

 Tundra polygons meet the decaying coastline, where plumes of sediment are visible entering the ocean

Tundra polygons meet the decaying coastline, where plumes of sediment are visible entering the ocean

By the time John Franklin arrived at Qikiqtaryuk in the summer of 1826, the people of Qikiqtaryuk had already taken their place in a two-way passage of trade. Iron, tobacco and beads headed east, while skins and furs from the Mackenzie Delta were taken west by a series of aboriginal traders to northeastern-most Asia, where Russians took the goods onwards to markets in China and Europe. There is no record of Franklin recognising an indigenous name for the island; instead he gave it the name Herschel Island. The Herschels were a family that emigrated from Germany to the UK as musicians, and achieved fame as the foremost astronomers of their time. Herschel Island is the name dominantly used today.

It was soon realised that the sheltered waters of Pauline Cove provided protection against the movements of ice that could crush overwintering ships like tin cans. Once the whalemen fleets arrived at Qikiqtaryuk - overwintering at the island from 1890 to 1912 - lifestyle changed rapidly for the indigenous populations. In interactions that spanned the spectrum from joyful to disastrous, the whalemen brought material goods, baseball, 4th July obstacle races, alcohol, buildings, gonorrhoea, syphillis, dances, theatre, and infections such as measles, influenza, typhus and tuberculosis. Soon after the establishment of regular whaling around Qikiqtaryuk, a mission was established, as well as a school, health clinic, and police outpost. Ultimately many Inuvialuit converted to Christianity. In 1909, the Bishop of Yukon oversaw the first legal marriage of a white man and an Inuit woman in the Canadian Arctic. The previous year, the price of whalebone collapsed, and fur trading took on a greater importance at Qikiqtaryuk. The influence of the missionaries is of course controversial, even though they may have seen themselves as providing an antidote to some of the damaging effects of the new cultural connections (disease, prostitution, alcohol abuse). Trading vessels visited Qikiqtaryuk each year until 1936, when Aklavik assumed the mantle of the region's trading centre.

Today the island is a Territorial Park, co-managed with the Inuvialuit. It remains a place for traditional harvesting of Arctic animals, but is also a base for the scientific investigation. Scientists interested in Arctic ecosystem dynamics can perform surveys of its biodiversity, while permafrost scientists can study changes in ground temperatures and the decay of the coastal bluffs.

 Scientists and park rangers meet at Pauline Cove

Scientists and park rangers meet at Pauline Cove

 Professor Chris Burn and Parks Canada Ranger Jay Frandsen take temperature readings of the permafrost ground

Professor Chris Burn and Parks Canada Ranger Jay Frandsen take temperature readings of the permafrost ground

It’s cold at Qikiqtaryuk; the annual mean temperature over the last decade has been -9 C. However, Qikiqtaryuk is one of the most striking examples of a place affected by anthropogenic climate change. Annual mean air temperatures since 1995 are 3 C higher than recorded in the years 1899-1903, the annual freeze-up of the ocean around Qikiqtaryuk now occurs nearly an entire month later than documented by the whalemen in the 1890s, and the temperature profile of the ground - decreasing to a depth of c. 50 m - shows a warming signal gradually diffusing downwards into the permafrost ground.

Thawing of the ice that binds the permafrost with warming temperatures is leading to dramatic degradation of the ground, most spectacularly seen on the coast. As the ice that binds the sediment thaws, the ground can collapse into a slurry, and expose a new face of permafrost ground that can then thaw, collapse, and so on. These features are known as retrogressive thaw slumps, and their total area increased by 160% between 1952 and 2000. Such an ice-rich coastline is vulnerable to thermal and mechanical erosion by waves, and the island currently experiences a stunning average erosion rate of half a metre per year, highest in the northwest where the coastal bluffs face storm-surge waves head-on. Rising sea levels and a shorter ice-protected season are likely to increase the rates of coastal erosion and thaw slumping.

 Deformed glacier ice revealed in the headwall of a thaw slump, slurry draining towards the sea below

Deformed glacier ice revealed in the headwall of a thaw slump, slurry draining towards the sea below

 Thaw slump, with grizzly bear for scale (look in the top right corner)

Thaw slump, with grizzly bear for scale (look in the top right corner)

In summer, walking over the green tundra, spotted with wildflowers and bog cotton, Qikiqtaryuk’s inextricable relationship with ice is not immediately obvious. But it is an island created by the advance of ice in a colder climate, its ground is bound by ice, and its coastline sheltered by sea ice in winter from waves. Its very existence is made less stable by warming temperatures.

By fortune of its placement next to the Mackenzie Trough and Mackenzie River, it became a hotspot for whales, fish, birds and bears - and therefore humans. Qikiqtaryuk has witnessed profound cultural changes. But now changes brought about by humans are, via the climate, causing profound physical changes to the island. It is also another example of where indigenous people and practices are on the front lines of climate change.

Oman work published in Journal of Structural Geology by Sam Cornish

Just a short post to say that the Journal of Structural Geology has accepted and published online my full-length research article "3D geometry and kinematic evolution of the Wadi Mayh sheath fold, Oman, using detailed mapping from high-resolution photography", co-authored with Mike Searle.

You can access the article for free in the next 50 days using this link: https://authors.elsevier.com/a/1VFeV_4N85EuBI

The permanent doi link is: https://doi.org/10.1016/j.jsg.2017.06.009

I'm excited to have my first peer-reviewed publication! I'm delighted that it stands as evidence that photography can be a useful tool for better understanding Earth processes. It's inconceivable that I would have been able to properly understand and elucidate the geological structure of the subject (the Wadi Mayh sheath fold) without performing a high-resolution photographic survey, producing scores of panoramas and even a 3D scene model using Agisoft Photoscan.

The structurally interpreted panoramas I think also have an aesthetic value which hopefully makes them accessible and meaningful in some way to those outside of the structural geology community.

Having said that, I do think that gaining some understanding of the Earth processes evident in an image can enhance the narrative and potency of that image. An open question: can a better understanding of Earth processes add something to our landscape photography?

 One of the annotated panoramas

One of the annotated panoramas

 A close up section of the above panorama and an illustration of how such folds can form under simple/general shear

A close up section of the above panorama and an illustration of how such folds can form under simple/general shear


The British Mountains of Ivvavik by Sam Cornish

In Inuvialuktun, Ivvavik means nursery, and so it is for porcupine caribou, who calve on the coastal plains every year. But step up from the plains and foothills into Ivvavik’s British Mountains, and you enter a landscape made over timescales that exist in a different conceptual space to lifetimes. As a nursery epitomises youth, this landscape epitomises age - it is a museum to geological processes and millions of years of landscape evolution. A museum stewarded by grizzly bears and illuminated by the clear Arctic sun.

 The Firth River is met by perpendicular-flowing tributaries in the  Aufeis Reach

The Firth River is met by perpendicular-flowing tributaries in the Aufeis Reach

The Firth River, which cuts down through the British Mountains, holds claim to be the oldest river in Canada. While most of Canada was being reshaped by the enormous Laurentide Ice Sheet, the Firth continued unabated, for it flowed over unglaciated land. During the geologically recent glacials of the Pleistocene, sea levels were as much 120 m lower than today. Siberia was linked across the Bering Strait in a cold union to Alaska and the Yukon, making up a swathe of land known as Beringia. Large parts of Beringian land escaped glaciation by remaining high and dry. Though cold, Ivvavik’s British Mountains were sheltered from moisture to the south and west by coastal mountain ranges, and stayed above the spread of glacial ice from the east by virtue of altitude. During glacial periods, this was a land of woolly mammoths, giant beavers and sabre-tooth cats; your full Ice-Age cast, plus a few unusual extras like the saiga antelope.

 Clouds gather over the British Mountains

Clouds gather over the British Mountains

The Firth’s history may even outlive these glacial periods. The fact that the Firth cuts a river valley perpendicular to the strike of the bedrock suggests that it incised hand-in-hand with the most recent episode of mountain uplift in the region c. 70 - 45 Myr ago.

 The Firth River flows across the geological grain

The Firth River flows across the geological grain

Rafting down the river would be a geologists’ dream, hurtling through a perfectly exposed succession of folded and faulted rocks, spanning seven hundred millions of years of depositional history and two episodes of major mountain building.

 A rafting party alight at Sheep Creek

A rafting party alight at Sheep Creek

The story begins with the breakup of an ancient supercontinent called Rodinia c. 700 Myr ago, plunging Ivvavik into a marine basin. Pressure rises as North America assembles at c. 400 Ma, compressing Ivvavik in the so-called Innuitian mountain building*. Next, a sudden hiatus as Ivvavik presides above sea level, shaped by erosion. The story recommences with reclamation by the sea in the late Carboniferous Period, and fluctuating relative sea levels through the Permian to Jurassic, leaving thin layers of colourful sandstones and limestones. Tension then enters the narrative - the Arctic Ocean begins to grow, involving major extensional faulting of the crust. By 100 Myr ago, we find Ivvavik on the shores of the Western Interior Seaway, connecting the Arctic to the Tropics and a favourite hangout for large dinosaurs. The blueprint for today’s Ivvavik is then established with mountain growth in the late Cretaceous and early Cenozoic, as the Kula Plate is entirely subducted at a shallow angle below Alaska and Canada, sweeping island arcs into the continent. In the Tlingit language**, Kula means ‘all gone’.

 Folded and faulted rocks exposed in the Firth River gorge

Folded and faulted rocks exposed in the Firth River gorge

Above the river gorge, interlocking pyramidal mountains form ridge lines of cool pastel shades, punctuated by frost-shattered tors of limestone. These tors are the artefacts of a larger bedrock mass subject to variable rates of weathering, leaving pinnacles and ridges proud above the retreating slope.

 Limestone tors project above the ridgeline

Limestone tors project above the ridgeline

Bone-coloured lobes of soil gradually creep down slope in a process known as solifluction. These lobes thaw in the summer and slip, saturated with water, over perennially ice-fastened ground.

 Solifluction lobes deliniate the topographic gradient

Solifluction lobes deliniate the topographic gradient

Even in summer, ice still persists in the higher reaches of the river valley. This is ‘aufeis’, formed as groundwater seeps out above the permafrost, and freezes on the surface. New ice obstructs groundwater, which eventually spills out above existing ice, to form successive ice sheets up to several metres in thickness combined.

 Persistent aufeis in the middle distance

Persistent aufeis in the middle distance

Though it is old, each year Ivvavik blooms into new life out of the dark whiteness of winter. Valleys and alluvial plains are adorned with grass that is golden green in sunlight, and scattered with spruce trees. Umber and terracotta mosses gather where moisture pools. Moose potter around by lakes, muskoxen splash water on their shaggy undercoats as they cross streams, bears snack on abundant berries of black, red and blue, and wolverines escape detection by all but the eagles above.

 Spruce trees grow where they can get a foothold in the permafrost ground

Spruce trees grow where they can get a foothold in the permafrost ground

An idyllic picture does, however, do a disservice to the struggles that these animals endure. In late Spring, the Porcupine Caribou herds etch trails across the high slopes of Ivvavik as they press on in single file through snow to their coastal nursery. The calving caribou attract relentless predation from bears, wolves and eagles, and they are feasted upon by swarms of mosquitos so dense they can asphyxiate resting caribou. Seeking relief, they turn to the mountains and the frigid temperatures of their overwintering grounds again, completing the longest migration of any land mammal, tracing 2,400 km over Alaska and NW Canada.

On these annual crossings, the caribou etch fresh wrinkles on the face of an ancient landscape.

 Caribou trails converge on an opening in the ridgeline

Caribou trails converge on an opening in the ridgeline

Ivvavik remains a pristine wilderness. Only about 100 human visitors step foot inside its 10,000 square km range each year. By comparison, 641 people summited Everest in 2016. An unlikely (though it transpires, necessary) place, to find an international airport. Thanks to its protected status and sheer isolation, however, Ivvavik will hopefully long thrive as a world of two timescales - the annual flashes of life, and the slow evolution of a mountain belt.

 An unlikely place for an international airport

An unlikely place for an international airport

 Sheep Creek's runway

Sheep Creek's runway

* Literature is very sparse for Ivvavik’s mountain building record and sources diverge on what the extent of the Innuitian Orogeny was, and what the continental configuration was at the time.

**The Tlingit are indigenous people of the Pacific northwest coast of North America

For more on the science and sights of Ivvavik, check out the Parks Canada guide to the Firth River Valley: http://parkscanadahistory.com/geology/firth-river-valley.pdf

The Mackenzie Delta by Sam Cornish

 The Mackenzie Delta, NW Territories

The Mackenzie Delta, NW Territories

Flying by helicopter above the Mackenzie River Delta, you bear witness to its vastness and almost unfathomable complexity. Lazily meandering channels feed into lakes like stems into leaves; movement of water through these plant-like systems becomes clear when rain fills the channels with silt. These silty waters act as a tracer for fluid flow, slowly feeding into clearer lakes and ponds.

 Silt delineates active flow routes

Silt delineates active flow routes

The main stem of the Mackenzie is fed from the west arm of the Great Slave Lake, more than 1,700 km upstream, but only 156 m higher in elevation. In total, the Mackenzie watershed drains an area of tundra and taiga forest more than seven times the size of the UK. It is a vast and wild landscape, where black spruce trees make shallow roots in permafrost ground. The annual frost heave and thaw of the upper soil gives rise to ’Drunken Forest’  - tilted trees, propping each other up.

The delta itself branches out just downstream of the confluence of the Mackenzie with the Arctic Red River at Tsiigehtchic. Upon opening it is joined by the Peel River, flowing northwards from the Ogilvie Mountains in Yukon.

As it empties into the Arctic Ocean’s shallow Beaufort Sea and the watercourse widens, the water slows considerably. With this loss of kinetic energy, much of the sediment - derived from mountain regions that fringe the watershed - settles out of the water. The accumulation of sediment further decreases the slope of the river channel, and gravitational instability leads to the propagation of new channels with more efficient courses.

 Sediment load suspended in a layered flow

Sediment load suspended in a layered flow

Since the retreat of glacial ice roughly ten thousand years ago this process has been arranging and rearranging the pattern of watercourses in the delta, which now spans more than 200 km north to south, and 100 km east to west at its mouth.

Some local people know how to traverse this labyrinthine delta. By boat it is an exercise in navigation which requires significant skill, and the willingness to jump out into the soft sediment and push when the water proves too shallow.

 A labyrinthine network of ponds and channels

A labyrinthine network of ponds and channels

Discharging nearly 10,000 cubic m each second into the Beaufort Sea, waters from the Mackenzie River feed the distinctive freshwater lens of the Beaufort Gyre, maintained by anticyclonic winds driving convergence of buoyant surface fresh waters towards the centre of the gyre. The fate of freshwater in this gyre has critical implications for the stability of sea-ice, marine ecology and wider ocean circulation.

The delta islands and riverbanks are home to grizzly bears, moose, muskrats, minks and beavers. The channels see the passage of fish like the arctic cisco venturing upstream to spawn. In the spring, beluga whales come to calve. Migratory birds - snow geese, sandhill cranes, tundra swans - make the delta their summer home, and bald eagles breed.

This is by nature a changing landscape. But in recent decades, the permafrost which underpins the structural integrity of the land dissected by the watercourses has been thawing, and in places black thaw slumps degrade the banks.