The continental shelf: geological, legal, or geopolitical?

With Shell receiving conditional approval to drill in the Chukchi Sea in offshore Alaska, the phrase “continental shelf” has come up a lot lately. The term also appears whenever territorial disputes in the Arctic make the news. But maps such as this one published by the Economist don’t exactly clarify what the continental shelf is, nor how its geography and terrain are literally at the bottom of so many disputes in the Arctic and indeed worldwide. So how can we better depict this underwater terrain, especially up north?

The International Bathymetric Chart of the Arctic Ocean (IBCAO) is the gold standard when it comes to cartographically displaying the texture of the continental shelf in the Arctic. The map has a resolution of 500 meters and much of the data comes from state-of-the-art multibeam surveys. You can read more about how the map was made in a paper published in Geophysical Research Letters in 2012.

However, what the map doesn’t display is geopolitical data. It’s interesting, for instance, to overlay the outlines of countries’ exclusive economic zones (EEZs) onto the bathymetric data. But before we do that, let’s look a bit more at the shelf’s topography.

The geological shelf

Geology or politics at work? USCGC Healy (R) and Canadian Coast Guard Ship Louis S. St-Laurent (L) mapping the Arctic seafloor in 2011. Photo: University of New Hampshire/NOAA.

Geology or politics at work? USCGC Healy (R) and Canadian Coast Guard Ship Louis S. St-Laurent (L) mapping the Arctic seafloor in 2011. Photo: University of New Hampshire/NOAA.

Using the ETOPO1 1 Arc-Minute Global Relief Model available from the National Oceanic and Atmospheric Administration, I made a simple map in ArcGIS displayed at the top of this post of the continental shelves in the Arctic.* While the continental shelf exists in reality as an underwater extension of a continent, it’s important to remember that even the idea of a continent is a social construct. If we were to redraw the world’s continents from an underwater, continental-shelf based perspective, we likely wouldn’t divide North America and Asia.

With this in mind, it becomes clear why it will be so hard to divvy up the continental shelf. Due to the presence of countries on top of the continental shelves, they will ultimately not be so much geologically as politically defined. Is the much-disputed Lomonosov Ridge, for instance, an extension of the Canadian, Russian, or Danish continental shelf? The fact that each country could claim it based on supposedly objective bathymetric evidence demonstrates the malleability of geology to political aims.

Yet divide the shelves they will, and that’s because sizable deposits of oil, gas, and other natural resources lie in wait. The continental shelves is where all Arctic offshore drilling will occur, with drilling looking something like this Gazprom diagram. As the U.S. Geological Survey stated in 2008, “The extensive Arctic continental shelves may constitute the geographically largest unexplored prospective area for petroleum remaining on Earth.” Their survey did not include the oil and gas resources that might lie in the seabed in the middle of the Arctic Ocean where the continental shelves drop off. By the time technology reaches a state where deepwater drilling in the Central Arctic Ocean becomes possible, humanity will hopefully have transitioned away from relying on fossil fuels.

Viewed in 3D, the nearly “landlocked” nature of the Arctic Ocean becomes evident, too. The Arctic Ocean is the world’s smallest, shallowest ocean. Its low average depth of ~1,000 meters is partly a result of the extension of many continental shelves, especially Russia’s, far into the ocean. The oil and gas exploration taking place on the shelf right now is therefore happening in relatively shallow water. Shell’s plans this summer on the Alaskan continental shelf entail drilling in water depths of about 42 meters. This is much shallower than deepwater drilling, which is typically characterized as occurring in depths of more than 150 meters. While Arctic offshore oil and gas drilling faces a number of environmental challenges, deepwater is not one of them at the moment.

A 3D perspective also illustrates the degree to which Russia faces the north. Its major rivers, the Ob, Yenisey, and Lena, drain out to the Arctic Ocean. The image below reveals how the Ob River cuts a chasm into the tundra as it rushes north. In the Soviet era, some politicians and scientists sought to reverse the northward flow of the country’s three major rivers so that they would irrigate the deserts of Central Asia for agriculture instead of “wastefully” flowing into the Arctic Ocean. Now, as the country turns north again and looks out towards a warming ocean with new possibilities for shipping and natural resource extraction, many Russians may be glad that their rivers still flow to the “northern icy sea,” as the Arctic Ocean is called in Russian (северный ледовитый океан).

The legal shelf

The continental shelf is knee-deep in legalities, clauses, and commissions. Article 76 in the United Nations Convention on the Law of the Sea defines the continental shelf of a Coastal State as:

“the seabed and subsoil of the submarine areas that extend beyond its territorial sea throughout the natural prolongation of its land territory to the outer edge of the continental margin, or to a distance of 200 nautical miles from the baselines from which the breadth of the territorial sea is measured where the outer edge of the continental margin does not extend up to that distance.”

The treaty was adopted in 1982, riding the crest of an upswing in the usage of the phrase “continental shelf” in English language publications as evinced by this Google ngram.

It’s hard to materially grasp the notion of the continental shelf when it is defined in terms of nautical miles, baselines, and continental margins – terms unfamiliar to most laypeople, which is why maps that integrate geology and geopolitics are important. In the Arctic, the two are inseparable, after all. The territorial disputes there all hinge on each Arctic coastal state’s claims to their respective continental shelf. Once a claim is recognized, a country earns the exclusive right to explore and exploit its resources, both living and non-living.

Claims are submitted to the United Nations Commission on the Limits of the Continental Shelf (UN CLCS), which is composed of 21 mostly male engineers, geologists, hydrographers, and other scientists from around the world. Members are elected for five year terms, with the current term lasting from 2012-2017. All of the commission’s members have real jobs, meaning that the UN CLCS is a side gig for them. That may explain why the commission’s website hasn’t been updated since September 2013. This group makes recommendations on country’s submitted claims, but they are expressly apolitical and often will not consider data from disputed areas. As such, countries can opt to only submit data in undisputed areas, coordinate claims with neighboring countries, or even make a joint claim.

Once a country’s submitted geological information is deemed scientifically sound, it is up to neighboring states to mutually delimit their borders. The United Nations will not delimit any borders on the continental shelf. If the countries can’t agree between themselves, they can go to the International Court of Justice – as happened in 1993 between Denmark and Norway over the area between Greenland and Jan Mayen. Canadian law professor Michael Byers has written a book called International Law and the Arctic that goes into the various submission options in much more detail for readers who are interested (and the section on continental shelf claim submissions is freely available to read on Google Books, too).

The geopolitical shelf

Now we can take a look at the bathymetric data with some geopolitical data overlaid. As the map above reveals, Russia has by far the largest continental shelf of any Arctic country. It’s no surprise that the country has moved the quickest of all the Arctic coastal states in exploiting its offshore oil and gas, for it simply has a much bigger amount of offshore territory to exploit. In Canada, by contrast, the country’s archipelago almost extends to the northernmost edge of the continental shelf. Delineations of the continental shelves and the respective EEZs also affect where current oil and gas exploration can take place. On the one hand, resolving territorial claims can be conducive to extraction since it removes gray areas from the map. Transnational corporations will simply not drill for oil in areas where the legal regime is unclear. On the other hand, corporations do have to be acutely aware of where EEZs lie so as not to wander into another country’s zone. In 2012, Shell’s leases in the Burger Prospect in the Chukchi Sea, issued by the U.S., stopped just before the boundary with the Russian EEZ. (This year’s exploration plans will take place a little bit farther west.) 

Shell's leases in 2012 go almost all the way up to the Russian EEZ.
A map of continental shelves doesn’t just hint at where future territorial claims and oil and gas exploration may take place. It also helps shed light on past movements of humans. For instance, Alaska and Chukotka, in eastern Russia, pretty much look like they lie on one extended sunken landmass, which some refer to as Beringia. This name evokes the migration that humans from Northeast Asia made across the Bering Strait to North America some 18,000 years ago. Back then, such political constructs of nations and continents didn’t exist. Instead, a grassy tundra covered the land for as far as the eye could see. Today, Beringia is an undersea relic of the Ice Age, with beluga whales and walruses swimming above the watery landscape once crossed by humans. Imagine how the geopolitics of the Arctic would differ today if the sea level was a few hundred feet lower and the continental shelves of the Arctic rose above the surface of the water.


*After making these maps, I came across GEBCO’s higher-resolution 30-arc second model gridded bathymetric chart of the oceans, which I will use in future maps.

Arctic Satellite Image of the Week: Russia discovers a new island in its Arctic

Landsat-8 image of new island discovered near Russia.

Landsat 8 image taken on June 16, 2013 of new island discovered near Russia. Image from NASA via USGS Earth Explorer.

In September 2013, two military helicopter pilots transporting equipment from Tiksi, a port city in northeast Russia, to the New Siberian Islands spotted a previously unknown island in the Laptev Sea. The discovery took place just a little ways south of the main shipping lanes used for the Northern Sea Route and has now been corroborated by geological surveying. The Russian-language version of Popular Mechanics notes that the small, low-lying island has been christened “Yaya,” or “Яя” in Russian. The rhyming name comes from the Russian word “Я,” which means “I”, for the pilot of each Mi-26 helicopter essentially shouted, “It was I who found it!” when they spotted the scrap of land.

The pilots happened to fly over the island (73°59′25″ N, 133°05′28 E) in September, when Arctic sea ice is at its lowest extent. September is the usually the first entire month to be open to shipping along the Northern Sea Route, too. I was unable to find cloud-free Landsat 8 satellite images taken over the location of the new island in September, or any of the other relatively ice-free months for that matter (July, August, and October), but I was able to find a cloud-free image taken on June 16, 2013, when the water was still frozen solid. Even despite all the thick sea ice surrounding the brown speck of land, it still manages to stick out.

Geographically speaking, the discovery reveals the extent to which the Arctic – especially the eastern Russian Arctic – still remains poorly mapped. It’s rare to hear of new islands – however small – being discovered elsewhere in the world unless they’re due to some recent volcanic activity.

Map of new island's location and Russia's new territorial waters.

Map of new island’s location and Russia’s new territorial waters.

New Siberian Islands Buildup?

Legally speaking, while the island is small, its discovery does have certain implications under the United Nations Convention on the Law of the Sea (UNCLOS). All of the waters around Yaya Island already fall within Russian’s exclusive economic zone (EEZ). But Section II explains that territorial seas extend 12 nautical miles outward from a country’s coastline. Thus, with the addition of the island to Russian territory, the country will gain 452 square kilometers of territorial seas. Once classified as territorial seas, then the water surface area, the air column above it, and the water column and seabed below it all become part of the country’s sovereign area.

UNCLOS also specifies that countries cannot levy charges on foreign ships for passing through their territorial waters, let alone EEZs. Yet because the waters are ice covered for a majority of the year, Russia is able to enforce additional regulations to prevent pollution, including by levying charges, under Article 234.

Yaya Island’s existence will cause hardly any large-scale changes in the eastern Russian maritime Arctic. But what could be more of a game-changer is the uptick in military-related activities occurring around Tiksi and the New Siberian Islands. The two helicopters that spotted Yaya were, as mentioned, ferrying unspecified equipment to the New Siberian Islands in September 2013 – one year before Russia re-opened a former Soviet military base there. So perhaps more than the discovery of the island, it’s actually the discoverers who form the real story behind the headline. In next week’s Arctic satellite image of the week post, I’ll look more into the military buildup taking place at what was their destination: the New Siberian Islands.

Revisualizing the cryosphere

Earlier this week, I participated in the National Science Foundation (NSF)’s Polar Data Visualization Hackathon in New York City. Remote sensing scientists, glaciologists, visualization experts, and designers all participated in the two-day workshop, held at the Parsons School of Design. The two-day meeting brought together all of these people so that they could harness their backgrounds to discuss how to make possible better visualizations of the Arctic and Antarctic. Sessions discussed topics from the highly technical, like “Open-source Polar Data Workflows with Tangelo Hubs,” to ones more focused on finessing the end product, like how to best display sea ice retreat to general audiences.

The workshop in New York was a sea change from the conference I had attended just a day before in Reykjavik: Arctic Circle, the largest international conference on the future of Arctic development. Northerners like the president of Iceland, the prime minister of Finland, and the former prime minister of Greenland were clear reminders of the fact that the Arctic is home to four million people. Thus, no quote put the two events in starker contrast than when one participant at the NSF workshop asked of the scientists:

“Please just remember to put the cities and towns of the Arctic on the map!”

Whereas Arctic Circle privileged the places, people, and natural resources of the Arctic – the lived environment, if you will – the NSF hackathon focused more on the geophysical features of the region. Sea surface temperature, sea ice extent, ice cores – these were the topics discussed by scientists. Marine-terminating versus land-terminating, hanging glaciers and ice-dammed lakes – such glaciological vocabulary would probably have gone right over the heads of many of the attendees at Arctic Circle. Meanwhile in New York, designers like Jer Thorpe talked about things like the “ooh/ahh factor” necessary for creating successful visualizations – ideas that would have been useful for the few presenters at Arctic Circle who put entire paragraphs of text in Times New Roman on a PowerPoint slide.

Yet while Arctic Circle attendees probably wouldn’t forget to include cities and towns on a map of the Arctic, they might neglect to include other features, like the seasonal dimension of Arctic sea ice. The area isn’t going to be open year-round for shipping, at least not anytime soon, due to the persistence of winter sea ice. Another example could be a map showing bold plans for northern infrastructure, which might overlook including the location of permafrost.

It’s hard to simultaneously depict human and physical phenomena in the Arctic without making a map look too busy. But doing so when possible would emphasize the highly intertwined nature of humans and nature.

While they emphasized different features in the earth’s polar regions, Arctic Circle and the NSF workshop hammered home the point that the Arctic matters. I long for the day when Greenland will be included in maps such as Vision of Humanity’s “Global Peace Index,” below, rather than just being a sorry gray or white featureless triangle on a map with “No Data” as an excuse.

Global Peace Index map by Vision of Humanity.

Global Peace Index map by Vision of Humanity.

Cryosphere connections

With that in mind, here are some visualizations for the week. The first map shows the cryosphere (sea ice extent in October 2014 and permanent land ice) and global shipping activity in 2004. The second map shows the cryosphere and global flight activity. They’re not really meant to be useful so much as to provoke thought about different ways to visualize the poles and the earth itself. I’ve chosen to use a stereographic projection, which retains the highest accuracy at the poles. I’ve also decided not to include any cities (except for Nuuk, Greenland as a reference point) or land masses, since I am more interested in showing the connections and relations between areas of the globe.

A polar stereographic view of world shipping activity.

A polar stereographic view of global shipping activity. Nuuk is the orange dot.

This image shows all the world’s shipping activity from October 2004-2005. The data is provided by the National Center for Ecological Analysis and Synthesis. The Arctic actually has a fair amount of traffic compared to the oceans around Antarctica, where the main route is from Hobart, Tasmania down to the Australian Antarctic Division’s research station. This helps elucidate the differences between the Arctic and Antarctic, especially since many people think of them as one and the same.

Lots of ships sail across the North Atlantic, with a spur leading off to the southwest coast of Greenland. Shipping remains one of the most important ways to supply communities in the Arctic. Even though this mode of transportation can’t occur year-round in the region, shipping is still one of the cheapest means of moving items from one place to another. It’s much cheaper than flying on a global scale, certainly, but especially in the Arctic given the paucity of flight connections (as the next map shows). It’s also interesting to notice the few faint blue lines that cross the Arctic ice cap; some even go into Antarctica at the bottom, and I’m not sure why.

We can also see what happens when we project a map based on the poles: areas far away, like Australia, get massively distorted. The continent appears to be the size of Asia! It’s the Southern Hemisphere equivalent of the Greenland Problem.


A polar stereographic view of global flight activity. Nuuk is the orange dot.

This map demonstrates how the poles are actually quite cut off from the global air traffic network. A lot of flights cross over the Arctic ice cap, since the area provides a shortcut for planes travelling between Asia and North America.* (I’ve written about this topic previously in the context of Arctic search and rescue.)

The image also reminds us how difficult it remains to fly to many Arctic destinations. There aren’t too many blue lines that terminate in the circumpolar north. It is possible to see a little bright spot in the North Atlantic though, to the right of Greenland: that’s Iceland, which has turned into something of an air traffic hub for flights between North America and Europe in recent years.


* The global flight routes depicted are based on great circle distances, which find the shortest line between two points on the earth. A more realistic map of global flight activity would show routes more organized into virtual traffic lanes in the sky.