History Podcasts

Have map projections and distortions ever affected treaties?

Have map projections and distortions ever affected treaties?

Has there ever been a case of an unfair treaty occur anytime through history due to use of biased map projections, either accidentally or deliberately?


One example would seem to be the 1867 treaty by which the United States purchased Alaska from Russia. The issues that arose are described Michael Byers and James Baker by in their book International Law and the Arctic.

The border between the two countries was to be in the Bering Sea and Bering Strait. However, as Byers and Baker observe:

… the 1867 Convention was silent on the type of line, map projection, and horizontal datum to be used in depicting the boundary. The two countries, which took different approaches to mapping, were consequently unable to agree on the precise location of the line.

Vlad Kaczynski, quoted by Byers & Baker elaborated:

Cartographers normally use two types of lines to delineate marine boundaries. These are rhomb [rhumb] lines and geodetic lines (also known as great circle arcs) that are used on two common map projections, Mercator and conical. Depending on the type of line and map projection used, lines will either appear as straight or curved lines. For example, a rhomb line will be a straight line on a Mercator projection, whereas a geodetic line is curved. Because each country interpreted the line described in the 1867 Treaty as a straight line, the Soviet Union depicted the Bering Sea marine boundary as a rhomb line on a Mercator projection whereas the US used a geodetic line on a conical projection. While both appear as straight lines on their respective map projections, each country's claim maximized the amount of ocean area and seafloor under their respective control.

  • Michael Byers & James Baker, International Law and the Arctic, Cambridge University Press, 2013, p33

This led to a disputed zone of approximately 15,000 square nautical miles. Each side, presumably felt the other's claims were 'unfair'. The dispute wasn't resolved until the Bering Sea Treaty was signed in 1990, some 123 years after the original treaty was signed.


Types of Map Projections

The ways in which we visualize the world are varied- we have pictures, maps, globes, satellite imagery, hand drawn creations and more.

What kinds of things can we learn from the way we see the world around us?

For centuries mankind has been making maps of the world around them, from their immediate area to the greater world as they understood it at the time. These maps depict everything from hunting grounds to religious beliefs and speculations of the broader, unexplored world around them.

Maps have been made of the local waterways, trade routes, and the stars to help navigators on land and sea make their way to different locations.

How we visualize the world not only has practical implications, but can also help shape our perspectives of the Earth we live in.

There are many kinds of maps made from a variety of materials and on a variety of topics.

Clay tablets, papyrus, and bricks made way for modern maps portrayed on globes and on paper more recent technological advances allow for satellite imagery and computerized models of the Earth.

Certain map projections, or ways of displaying the Earth in the most accurate ways by scale, are more well-known and used than other kinds.

Three of these common types of map projections are cylindrical, conic, and azimuthal.


RELATED ARTICLES

Much of this is due to technical reasons, said Mr Wan, while others inconsistences are caused by ideological assumptions that can change the way we see the world.

The biggest challenge is that it is impossible to portray the reality of the spherical world on a flat map – a problem that has haunted cartographers for centuries.

One of the best alternatives to the Mercator projection was presented in 1974 by D. Arno Peters (pictured). The Gall-Peters projection makes seeing the relative size of places much easier. However it also has its flaws as certain places appear stretched, horizontally near the poles and vertically near the Equator

A depiction of the world by Henricus Martellus. It's said that Columbus used this map or one like it to persuade Ferdinand of Aragon and Isabella of Castile to support him in the early 1490s. The map was made by a German cartographer living in Florence and reflects the latest theories about the form of the world and the most accurate ways of portraying it on a flat surface

WHAT IS WRONG WITH THE MERCATOR MAP?

Africa is around 14 times larger than Greenland and yet on the map both are almost same size.

Brazil is more than five times larger than Alaska, yet Alaska is larger than Brazil on the map.

The map suggests that Scandinavian countries are larger than India, whereas in reality India is three times the size of all Scandinavian countries put together.

While it looks like Europe is larger than North America on this map, in reality the reverse is true. Russia also isn't as large as it is depicted, with Africa larger than Russia in reality.

As a result, shapes of world maps have typically been diverse, ranging from hearts to cones. But the diversity gradually faded away with one model, invented by Gerardus Mercator, surpassing the others.

The familiar 'Mercator' projection gives the right shapes of land masses, but at the cost of distorting their sizes in favour of the wealthy lands to the north.

For instance, in the Mercator projection, north America looks at least as big, if not slightly larger, than Africa. And Greenland also looks of comparable size.

But in reality Africa is larger than both. In fact, you can fit north America into Africa and still have space for India, Argentina, Tunisia and some left over, notes Mr Wan.

Greenland, meanwhile, is 1/14th the size of the continent as can be seen in Gall-Peters equal projection, which provides the correct proportion of land mass to the continents.

The map suggests that Scandinavian countries are larger than India, whereas in reality India is three times the size of all Scandinavian countries put together.

As well, as this, it seems the fact that our maps typically put north at the top is a mere convention but has been accepted as correct in most of the world.

Looking back, the diversity of maps can reveal a history of the world.

The Chinese Globe which was made for the Chinese Emperor in 1623. The creators exaggerated the size of China and placed it in the middle of a world that otherwise consisted mainly of small offshore islands

The Werner heart-shaped project of the world (left) The fact that our maps typically put north at the top is a mere convention but has been accepted as correct in most of the world. Pictured on the right is a Mercator map turned on its head

For instance, The ‘Be On Guard!’ map was created in 1921 when infant USSR was threatened with invasion, famine and social unrest.

To counter this, designers such as Dimitri Moor were employed to create pro-Bolshevik propaganda.

Using a map of European Russia and its neighbours, Moor's image of a heroic Bolshevik guard defeating the invading 'Whites' helped define the Soviet Union in the Russian popular imagination.

An earlier map, called the Hinese Globe, created in 1623 reveals the ancient Chinese view of the world.

Made for the Chinese Emperor, this is the earliest known Chinese terrestrial globe, and a fusion of East and Western cultures.

The creators exaggerated the size of China and placed it in the middle of a world that otherwise consisted mainly of small off¬shore islands.

A century earlier, the 1507 Waldseemuller map named and envisaged America as a separate continent for the first time.

Photo of a genuine hand drawn world map, it was drawn in 1844 and therefore the countries are named as they were in that period. The biggest challenge is that it is impossible to portray the reality of the spherical world on a flat map

Perhaps to emphasise the independent existence of the Americas, the map shows what we now know is the Pacific lapping the western coast of South America, though its existence was only confirmed years late.

In 2005, Google Earth presented a world in which the area of most concern to the used could be at the centre, and which - with mapped content overlaid - can contain whatever you think is important.

Almost for the first time, the ability to create an accurate map has been placed in the hands of everyone, and it has transformed the way we view the world. But it comes at a price.

There are few, if any, agreed standards about what should be included, and the less populated and 'less important' regions get ignored.

The infant USSR was threatened with invasion, famine and social unrest. To counter this, brilliant designers such as Dimitri Moor were employed to create pro-Bolshevik propaganda. Using a map of European Russia and its neighbours, Moor's image of a heroic Bolshevik guard defeating the invading 'Whites' helped define the Soviet Union in the Russian popular imagination

Google Maps claims that it is on a 'never-ending quest for the perfect map', but Jerry Brotton, historian of cartography and the author of A History of the World in Twelve Maps, isn't so sure

A Mercator map created in 1569. In the Mercator projection, north America looks at least as big, if not slightly larger, than Africa. And Greenland also looks of comparable size

Today, billions of searches are made on Google Maps each day, helping people navigate their way around, streets, towns and countries.

Google Maps claims that it is on a ‘never-ending quest for the perfect map’, but Jerry Brotton, historian of cartography and the author of A History of the World in Twelve Maps, isn’t so sure.

He argues that all maps are of their time, their place and serve certain purposes.

‘No world map is, or can be, a definitive, transparent depiction of its subject that offers a disembodied eye onto the world,’ he writes.

‘Each one is a continual negotiation between its makers and users, as their understanding of the world changes.’


How to Make Maps and Influence People

Maps are one of the most trusted forms of communication – which makes them great for getting your point across. A look at the dark art of cartographic persuasion.

Geoff McGhee is a journalist and data visualizer at Stanford University’s Bill Lane Center for the American West.

Data Points is a new series where we explore the world of data visualization, information graphics, and cartography.

We depend on maps every day—to navigate, to check the weather, to understand the world. Perhaps because maps typically depict the real world, they are one of the most trusted forms of visual communication.

"Maps have inherent credibility. We are trained since childhood to rely on maps," says Paul "P.J." Mode, a collector and amateur map historian. But that trust can be taken advantage of, he says, by people who use maps to promote their own point of view.

Mode, who uses infographics extensively in his law practice, has spent the past three decades collecting examples of what he calls "persuasive cartography," which range from satirical cartoons with geographical elements and politically loaded schoolroom maps to vintage data visualizations that would not be out of place on the Internet today.

This genre of cartography is often called "propaganda maps," says Mode, but he prefers the less pejorative label "persuasive cartography." Just because they’re persuasive, he argues, doesn't mean they’re inaccurate. "I collect both—there are some pieces that are persuasive because they are completely accurate and that marshal facts in a way that is very powerful.” He adds, “There are others that use maps that are not at all accurate, but what is powerful is the imagery. And then there are maps that are incredibly deceptive."

Mode donated his collection of over 700 maps to the Cornell University Library in 2014. In September, the university’s Division of Rare & Manuscript Collections launched an online archive of images from the collection. About 300 works have been digitized and published so far, dating from the distant past to as recent as 2008.

Much like maps that achieve viral popularity today, classic maps seen in Mode’s collection often sought to provoke shock or outrage. Examples include oddly familiar broadsides against wealth inequality: an 1877 cartoon in the German edition of Puck magazine showing the oligarchs William Vanderbilt, Jay Gould, Cyrus West Field, and Russell Sage carving up the country into pieces a 1884 political poster by the Democratic Party accusing Republicans of giving away 38 percent of the United States to railroad corporations (the real amount was closer to 9 percent, Mode notes, adding that “the effect of the deception was massive”). Even the deepest skeptic of alcohol prohibition would be struck by this 1888 map of taverns in New York City and by the dense concentration of saloons, bordellos, and pawnshops within a few blocks in Chicago in an 1894 map created by temperance advocates.

If the core purpose of maps is to portray spatial relationships, it’s not surprising that many of Mode’s maps seem to emphasize a sense of proximity, even encroachment. In the 1920s, after the Treaty of Versailles had forced Germany to make territorial concessions, a popular nationalist map prefigured later aggressions by making it possible, Mode writes, “to claim not only all lost territories but even areas outside pre-war Germany simply by pointing to their German cultural character.”

Indeed, fear of encroachment seems to be a popular motivator in these charts, as illustrated by a map made for a successful campaign to keep nuclear warships out of New York Harbor in the 1980s. The map, made by a church-based antinuclear group, overlays a giant red paint splash on a map of the city, next to text warning that a warhead or reactor accident could engulf Manhattan in a 28-mile cloud of plutonium dust. “It’s an example of what can be done using maps,” says Mode, “to make a point to the general public without using any science.”

Not surprisingly, a number of memorable images from the collection were produced in wartime. A Japanese map dating from the Russo-Japanese War depicts Russia as a giant octopus astride Europe and Asia. Menacing octopuses seem to be a popular metaphor, as Japan was in turn depicted in World War II, in a Dutch poster urging the liberation of the Netherlands’ former Indonesian colonies. The British produced vivid war graphics as well, such as the arguably correct “Nazi War Aims—Grab! Grab!! Grab. ” in 1939.

But maps in the collection also draw on pride, uplift, and a sense of humor. During the movement to enfranchise women nationwide, a Puck magazine graphic entitled “The Awakening” shows Lady Liberty astride the newly incorporated western states and territories—where women had the vote—looking back at yearning masses of women in the East.The August 1895 cover of Judge magazine, a rival to Puck and its timeless Thomas Nast cartoons, shows the U.S. as a curious Uncle Sam—his eye Washington, D.C., his nose Florida—peering intently down at Cuba, where an insurgency had just begun, and where Theodore Roosevelt would later lead an invading force to wrest the island from the Spanish.

Mode says the historical masters of persuasive maps, though, were the British during their imperial height, when maps helped promote the size, power, and presumable invincibility of a small island nation’s global empire. They used not just maps themselves, he says, but also visual and geographical tactics to shape the viewer’s perception.

An extrawide 1890 map of the British Empire, Mode points out, extends 490 degrees of longitude across a globe with only 360 degrees—ensuring that India, Australia, and New Zealand appear not once but twice. “It really is in many ways an important example of how the British used cartography to emphasize the size, extent, and power of the British Empire.”


Why Making Accurate World Maps Is Mathematically Impossible

Jorge Luis Borges once wrote of an empire wherein “the Art of Cartography attained such Perfection that the map of a single Province occupied the entirety of a City, and the map of the Empire, the entirety of a Province.” Still unsatisfied, “the Cartographers Guilds struck a Map of the Empire whose size was that of the Empire, and which coincided point for point with it.” But posterity, when they lost their ancestors’ obsession for cartography, judged “that vast Map was Useless, and not without some Pitilessness was it, that they delivered it up to the Inclemencies of Sun and Winters.” With that enormous map, in all its singular accuracy, cast out, smaller, imperfect ones presumably won the day again.

With that well-known story “On Exactitude in Science,” Borges illustrated the idea that all maps are wrong by imagining the preposterousness of a truly correct one. The Vox video “Why All World Maps Are Wrong” covers some of the same territory, as it were, first illustrating that idea by slitting open an inflatable globe and trying, futilely, to get the resulting plastic mess to lie flat.

“That right there is the eternal dilemma of mapmakers,” says the host in voiceover as the struggle continues onscreen. “The surface of a sphere cannot be represented as a plane without some form of distortion.” As a result, all of humanity’s paper maps of the world–which in the task of turning the surface of a sphere into a flat plane need to use a technique called “projection”–distort geographical reality by definition.

The Mercator projection has, since its invention by sixteenth-century Flemish cartographer Gerardus Mercator, produced the most widely-seen world maps. (If you grew up in America, you almost certainly spent a lot of time staring at Mercator maps in the classroom.) But we hardly live under the limitations of his day, nor those of the 1940s when Borges imagined his land-sized map. In our 21st century, the satellite-based Global Positioning System has “wiped out the need for paper maps as a means of navigating both the sea and the sky,” but even so, “most web mapping tools, like Google Maps, use the Mercator” due to its “ability to preserve shape and angles,” which “makes close-up views of cities more accurate.”

On the scale of a City, in more Borgesian words — and probably on the scale of a Province and even the Empire — Mercator projection still works just fine. “But the fact remains that there’s no right projection. Cartographers and mathematicians have created a huge library of available projections, each with a new perspective on the planet, and each useful for a different task.” You can compare and contrast a few of them for yourself here, or take a closer look of some of the Mercator projection’s size distortions (making Greenland, for example, look as big as the whole of Africa) here. These challenges and others have kept the Disciplines of Geography, unlike in Borges’ world, busy even today.

Related Content:

Based in Seoul, Colin Marshall writes and broadcasts on cities and culture. He’s at work on a book about Los Angeles, A Los Angeles Primer, the video series The City in Cinema, the crowdfunded journalism project Where Is the City of the Future?, and the Los Angeles Review of Books’ Korea Blog. Follow him on Twitter at @colinmarshall or on Facebook.


Transcript [ edit ]

  • Mercator
    • You're not really into maps.
    • You're not a complicated person. You love the Mercator projection you just wish it weren't square. The Earth's not a square, it's a circle. You like circles. Today is gonna be a good day!
    • You have a comfortable pair of running shoes that you wear everywhere. You like coffee and enjoy The Beatles. You think the Robinson is the best-looking projection, hands down.
    • You like Isaac Asimov, XML, and shoes with toes. You think the Segway got a bad rap. You own 3D goggles, which you use to view rotating models of better 3D goggles. You type in Dvorak.
    • National Geographic adopted the Winkel-Tripel in 1998, but you've been a W-T fan since long before "Nat Geo" showed up. You're worried it's getting played out, and are thinking of switching to the Kavrayskiy. You once left a party in disgust when a guest showed up wearing shoes with toes. Your favorite musical genre is "Post–".
    • They say mapping the Earth on a 2D surface is like flattening an orange peel, which seems enough to you. You like easy solutions.You think we wouldn't have so many problems if we'd just elect normal people to Congress instead of Politicians. You think airlines should just buy food from the restaurants near the gates and serve that on board. You change your car's oil, but secretly wonder if you really need to.
    • You want to avoid cultural imperialism, but you've heard bad things about Gall-Peters. You're conflict-averse and buy organic. You use a recently-invented set of gender-neutral pronouns and think that what the world needs is a revolution in consciousness.
    • You think this one is fine. You like how X and Y map to latitude and longitude. The other projections overcomplicate things. You want me to stop asking about maps so you can enjoy dinner.
    • Yes, you're very clever.
    • Really? You know the Waterman? Have you seen the 1909 Cahill Map it's based— . You have a framed reproduction at home?! Whoa. . Listen, forget these questions. Are you doing anything tonight?
    • You think that when we look at a map, what we really see is ourselves. After you first saw Inception, you sat silent in the theater for six hours. It freaks you out to realize that everyone around you has a skeleton inside them. You have really looked at your hands.
    • I hate you.

    /> add a comment! ⋅  /> add a topic (use sparingly)! ⋅  refresh comments!


    With COVID-19 cases falling in many parts of the world and vaccination programs ramping up at warp speed, international travel no longer seems like a distant dream.

    The Henley Passport Index, which has been regularly monitoring the world’s most travel-friendly passports since 2006, has released its latest rankings and analysis.

    The most recent data provides insight into what travel freedom will look like in a post-pandemic world as countries selectively begin to open their borders to international visitors.


    Russians settle Alaska

    On Kodiak Island, Grigory Shelikhov, a Russian fur trader, founds Three Saints Bay, the first permanent Russian settlement in Alaska.

    The European discovery of Alaska came in 1741, when a Russian expedition led by Danish navigator Vitus Bering sighted the Alaskan mainland. Russian hunters were soon making incursions into Alaska, and the native Aleut population suffered greatly after being exposed to foreign diseases. The Three Saints Bay colony was founded on Kodiak Island in 1784, and Shelikhov lived there for two years with his wife and 200 men. From Three Saints Bay, the Alaskan mainland was explored, and other fur-trade centers were established. In 1786, Shelikhov returned to Russia and in 1790 dispatched Aleksandr Baranov to manage his affairs in Alaska.

    Baranov established the Russian American Company and in 1799 was granted a monopoly over Alaska. Baranov extended the Russian trade far down the west coast of North America and in 1812, after several unsuccessful attempts, founded a settlement in Northern California near Bodega Bay. British and American trading vessels soon disputed Russia’s claims to the northwest coast of America, and the Russians retreated north to the present southern border of Alaska. Russian interests in Alaska gradually declined, and after the Crimean War in the 1850s, a nearly bankrupt Russia sought to dispose of the territory altogether.

    The czarist government first approached the United States about selling the territory during the administration of President James Buchanan, but negotiations were stalled by the outbreak of the American Civil War. After the war, Secretary of State William H. Seward, a supporter of territorial expansion, was eager to acquire the tremendous landmass of Alaska, one-fifth the size of the rest of the United States. On March 30, 1867, Secretary of State William H. Seward signed a treaty with Russia for the purchase of Alaska for $7.2 million. Despite the bargain price of roughly two cents an acre, the Alaskan purchase was ridiculed in Congress and in the press as “Seward’s folly,” “Seward’s icebox,” and President Andrew Johnson’s “polar bear garden.” In April 1867, the Senate ratified the treaty by a margin of just one vote.

    Despite a slow start in settlement by Americans from the continental United States, the discovery of gold in 1898 brought a rapid influx of people to the territory. Alaska, rich in natural resources, has been contributing to American prosperity ever since. On January 3, 1959, President Dwight D. Eisenhower signed a proclamation admitting the territory of Alaska into the Union as the 49th state.


    Mercator, it's not hip to be square

    Gerardus Mercator was a 16 th Century map genius. He did many things but arguably his biggest legacy is the invention of a map projection that bears his name, the Mercator projection. The projection has become widely used, not least as Web Mercator for web mapping. Yet it is also the bane of cartography because of the distortions it exhibits. In this blog I’ll review a little of why the Mercator projection can be useful, then explain how you can do away with it altogether when you need a far more suitable projection for your web map.

    What is it good for…?

    Mercator’s 1569 world map used his new cylindrical conformal projection, meaning it’s rectangular in shape and preserves angles across the map. That results in you being able to plot straight lines on the map and use them to give a bearing.

    The map was titled “Nova et aucta orbis terrae description ad usum navigantium emendate et accomodata” which translates as “new and improved description of the world amended and intended for the use of navigators”. Mercator made the map for navigation, and the underlying projection supported that purpose perfectly. He didn’t make the map projection for any other purpose. It’s a great projection for navigating.

    One consequence of the projection is that it grotesquely exaggerates northern and southern latitudes, warping the size of places relative to one another. Yet despite this weird view of the world, presented almost as a square, curiously it has become the view of the world we often see on school walls, in news media, and web maps.

    Debate over its utility is nothing new. In 1943, the New York Times stated that, “We cannot forever mislead children and even college students with grossly inaccurate pictures of the world.” So why is it so often used? Well, if you use the projection often enough people will believe it to be the de facto view of the world. They become challenged by seeing the world presented using other projections. And, of course, the huge revolution in mapping that the internet has supported has done its fair share to further embed the Mercator projection into our daily psyche.

    Web Mercator became the default web map tiling scheme for good reason – it was relatively simple to build a seamless, zoomable web map. Conformality meant that shapes were maintained and distortion was relatively low at large scales when zoomed in. The reason Web Mercator was suitable as the basis for early web mapping is that it creates a convenient square shape for the entire world if it is truncated at approximately 85° North and South of the Equator. Wherever you are on the map, up is due north, down is due south and west and east are always left and right. At large scales, conformality means square buildings remain square. This creates an attractive consistency from a software engineering perspective and avoids some of the confusion that sometimes comes with other projections.

    Absolutely nothing…

    So, Web Mercator is quite serviceable, particularly for large scale maps, or for regional mapping. But for small scale maps it is virtually useless. For instance, on a world map, Ellesmere Island in the Canadian arctic is shown approximately the same size as Australia. It isn’t. It’s 75,767 mi² in size and has a population of 146. Australia is 2.97 million mi² and has a population of 24.6 million.

    It’s also pretty much useless if you want to compare things across a map, and the smaller the map’s scale the bigger the problem. If you want to compare the Norwegian capital city of Oslo, at 59.9139° N with Singapore, at 1.3521°N you’ll find that Oslo appears 75% larger than Singapore at the same map scale.

    Here’s page 27 from my Cartography book (you’ve got a copy already right?) which shows how a common shape is modified through re-projection. And there’s Mercator in the bottom right. I wouldn’t get on a plane shaped like that.

    Huh? Say it again? How can these distortions be allowed?

    To be fair, there are distortions in every map projection because it’s impossible to convert a curved spherical (or ellipsoidal) surface to a flat plane without some squashing, stretching, or ripping. But the point here is to embrace the fact that distortions exist, and use a map projection that suits your map. If you’re printing a map it’s simple. Make the map using whatever projection you want, then send it off to the printer which, hopefully, won’t re-project it to Mercator. But it’s not quite as simple when publishing web maps.

    Ordinarily, if you publish features or tiles to be displayed in a web map it’ll likely be using Web Mercator, with all the inherent distortions whether you like it or not, and 99% of the time you most likely absolutely should not like them. Yet there they are. But the problem is compounded because of the people reading your map. The vast majority of people looking at your map (let’s say 99%) will be unaware of the distortions in the map which translate into visual biases as they try and interpret what they’re seeing. They will not even know that they are seeing things out of scale, relative to one another. So they are being misled. Which places an important additional requirement on you as the map maker – do not use Mercator, or Web Mercator for small scale maps or for any map where you are overlaying thematic content where visual comparison is crucial to interpretation.

    Instead, you need to use a projection with an altogether different property. Equal area projections are your best friend because they do not possess the same distortions and support visual comparison from place to place across the map. There is no exaggeration of sizes of one place to another. Perfect. So if I’m making a thematic web map, how do I do this? OK, I’m getting to that bit…hold on a moment longer. First we need a good case study to demonstrate the methods.

    A cartographer’s nightmare

    Fortunately there are a few of simple methods to banish Web Mercator from your maps forever and I’ll explain them using the recent 2019 Canadian general election data. Canada is a cartographer’s nightmare. It has a huge landmass that extends across a large north-south extent which sits squarely in the Web Mercator zone of highest distortion. It also has vastly differing population densities across its area from a more densely populated south to an increasingly sparse population in the north. Nearly 90% of the Canadian population live within 100 miles of the border with the United States.

    Here’s the results of the general election, showing the 338 Electoral districts, using Web Mercator as the underlying projection.

    So how would someone likely read this map? I see a lot of orange. In fact, Orange is the predominant colour and covers 52% of the map. Red is second at 28% coverage. The darker blue covers 13% and the lighter blue covers 7%. The green and independent parties don’t even show up at this scale (hooray for multiscale web maps!).

    Would it therefore surprise you to learn that out of the 338 Seats only 24 were won by New Democrats, the party shown in orange? They only had the fourth largest number of seats and took only 7% of the seats. The Liberals (red) won with 157 seats. The Conservatives (darker blue) came second with 121 seats. So the map is lying to you. The most prevalent colour on the map does not represent the winning party. And that’s a ridiculous message for the map of results to lead the reader towards.

    What’s more, because of the huge population disparities only 3 seats are voted for in Yukon, NW Territories and Nunavut. Everything above the 60 th parallel of latitude on this map (the top three-quarters of the map) is represented by 3 seats. The remaining 335 are voted on by people living below the 60 th parallel. So let’s at least have the courtesy to display the map using an equal area projection. Here’s the map shown using the Canada Albers Equal Area Conic projection.

    So much better already. Those horrible Web Mercator distortions are gone. That overbearing swathe of red and orange above the 60 th parallel of latitude has disappeared. Areas are now correctly sized to one another. This is a more truthful map. But an even more truthful map would reveal something of the distribution of the population and how it maps onto the availability of seats because there’s still an awful lot of colour representing sparsely populated areas.

    So let’s turn these static maps into web maps to demonstrate the alternative ways in which you can publish using anything other than Web Mercator, and at the same time illustrate a few alternative maps.

    Escaping Web Mercator method 1: Vector Tiles

    The first step is easy. You make the map in whatever projection you want in ArcGIS Pro. Then you publish your map using Vector Tiles. Simple. There’s really not much detail to the process but you can publish data to vector tiles in one of two ways, either right-click the layer you want to publish, go to Sharing and then Share As Web Layer.

    Alternatively, if your map contains multiple layers, select Web Layer > Publish Web Layer from the Share ribbon.

    The Share as Web Layer pane will open, and it’s then just a few clicks to configure your map. Give it a name, add a short summary and tags and then select the Vector Tile radio button.

    On the Configuration tab, you’ll see that the Tiling Scheme will be pre-populated to match your map’s projection. Just leave it pretty much as it is, and simply select the levels of detail you want. Remember, there’s no point publishing your map to a really large scale if neither the data or purpose support it.

    Hit publish, go grab a coffee, then come back to ArcGIS Online, log into your account and open your Hosted Tile Layer service in the Map Viewer. Job done! And you can then configure the web map as you want.

    So here’s a web map of the 2019 Canadian election results which uses the Canada Albers Equal Area Conic projection. You can get the full screen version here.

    Of course, one of the things you may want to add to your web map is another layer to drive some popups. Design them in ArcGIS Pro, and then change the fill and outline of your features to have no colour. Publish this as a feature service, add to your web map and they will automatically re-project to your non-Web Mercator vector tiles. If you click on the web map above you’ll see the popups, which also use colour coding for each winning party. This is important because the use of colour, especially for political parties, differs across the globe and can mean quite different political leanings.

    This map also modifies the view of the results by varying transparency based on population density. As population density becomes increasingly sparse, so the colour is increasingly transparent. It has the visual effect of receding (the technique is called value-by-alpha). Those areas with higher population densities come into focus and appear brighter. So this map more truthfully promotes the places where people live (and vote) rather than the unique values maps which treats geography as homogenous areas with a mutually exclusive block fill of colour according to who won that area.

    Finally, notice I’m not using a basemap. That’s because thematic maps are their very own basemaps in many situations. I’ve published all I need directly from ArcGIS Pro so there’s no reliance on standard basemaps which will have been published in Web Mercator. Trying to warp them to your projection will work, but it will warp any burnt in labels as well.

    And Vector Tiles aren’t a one-trick pony so here’s a completely different type of map, a waffle grid, along with labels for Territories, Provinces and Cities that was published as a single Web Layer from ArcGIS Pro. It’s based on this map made by Laris Karklis of The Washington Post. Full screen here.

    Escaping Mercator Method 2: Raster Tiles

    There’s going to be occasions where you create an interesting thematic map which the ArcGIS Online renderer will not support. You may also want to embed annotation into your map or add other graphical marks and effects that simply aren’t supported. For instance, on the map above the labels are all aligned horizontally but I might want them curved to the graticule to emphasise the projection being used. Design them as you wish in ArcGIS Pro then we’ll use a slightly different publishing approach.

    For this circumstance we simply revert to a technique that’s been possible pretty much ever since ArcGIS Online was born, and which can be implemented from ArcMap should you still be using that (are you? can I suggest you make the move to ArcGIS Pro?). It simply bakes everything on your map into a set of raster tiles.

    Once you’ve made your map using whatever projection you deem fit for your purpose, and whatever weird and wonderful mapping techniques, labeling and anything else you’re ready to publish. Use the Generate Tile Cache Tiling Scheme Geoprocessing tool to create a small xml file that captures your map’s projection and scales for publishing. Decide how many scales you’ll want the map to be viewed at. For this, just 1:18 million down to 1:4 million should suffice.

    Then, as before Share as Web Layer but make a couple of adjustments. Select Tile (not Vector Tile) and on the Configuration tab, select Tiling Scheme File in the Tiling Scheme dropdown. Point to the xml file you created earlier and the projection information and scales are loaded. Then hit Publish.

    Once your raster tiles have published, head on over to your ArcGIS Online account, open the Hosted Tile Layer in the Map Viewer and boom! There’s your map.

    Here’s a dot density web map that includes not only the winners, but all the other votes for parties that had at least a 1% share. At this scale 1 dot = 100 votes and shows the mix of colours. The way I made the map is not currently supported in ArcGIS Online yet here’s the map, in ArcGIS Online. Adding a popup using the same approach as before (invisible symbology, published as a hosted feature layer) brings your slippy raster tiles to life.

    The benefits of this approach are that it’s a terrific backup for anything that’s not supported in ArcGIS Online and you can still make your map look the way you want with ANY projection. The drawback is that everything is baked into the map so if you want components of your map to change at different scales (e.g. annotation sizes) then that has to be built into your map’s design in ArcGIS Pro. When each of the scales of raster tile are built, it uses the specifications you set for that scale in ArcGIS Pro (or ArcMap). Full screen here.

    Escaping Mercator Method 3: Cheat

    So the inevitable question remains – what if you neither have, nor want to use ArcGIS Pro (or ArcMap) to publish your maps into a non-Web Mercator projection? I’m led to believe there are some who prefer working in this way. Well, until* ArcGIS Online supports user-defined re-projection of your own data from within the web browser itself the only way you can go the non-Mercator route is by hunting for a hosted tile layer that someone else has published which you can then use to put your own content on top. This all depends on tags.

    For instance, I’ve published a basic version of the Canada basemap I used for the above maps without any thematic content. I added the tag ‘Albers’ so if you search for ‘Albers’ in ArcGIS Online you’ll find the basemap. It’s just a blank map:

    But you can then use your own data, or another dataset you found in ArcGIS Online and create a new map of that data in a more appropriate projection that Web Mercator. Here’s a set of soil types from the Living Atlas re-projected onto the basemap.

    Ditch Web Mercator – your map readers will thank you

    Well, they likely won’t thank you but unless they’re firing up ArcGIS Online to navigate the Atlantic Ocean on a small raft and they need a map projection that gives them bearings, they’ll be looking at a better map.

    Put simply, Web Mercator kills thematic maps. Its gross distortions affect people’s ability to decipher what they are seeing. You cannot effectively display unique values, choropleth maps, or dot density using Web Mercator. Neither can you overlay regularly tessellated shapes (squares, hexagons, triangles) or non-tesselating symbols used for binning (e.g. circles) on top of Web Mercator because the actual land area underneath each shape of the same size will decrease massively the further you get away from the equator. Using an equal area projection will solve this problem in one simple step.

    Remember, where projections are concerned there’s really no good default. Every map should be considered on a case by case basis depending on where in the world you’re mapping, the scale, purpose and content. It’s really not acceptable to think of Web Mercator as the web map default any more. Esri’s projection engine is integrated inside ArcGIS Online which supports the publishing of non-Web Mercator maps. If you’re unsure on which projection to choose then Projection Wizard will really help you. These two videos will also help get you up to speed with Coordinate Systems and Map Projections.

    The ArcGIS Pro documentation ‘Author a map for vector tile creation‘ gives you further details on the additional possibilities that vector tiles afford.

    It’s no longer hip to be square. Let’s raise the standards of our web maps, and particularly our thematic web maps because it is possible to re-shape your maps using any and all projections, and it isn’t difficult. Once you’ve made your web map in your new shiny non-Web Mercator projection it’s also supported in all your favourite apps like Web Appbuilder and Story Maps.

    Happy non-Web Mercator mapping!

    Thanks to Craig Williams and Bojan Šavrič for helping me with data and advice.

    * – I’m not hinting at this support coming any time soon but the best way to request this (or any) feature is to add requests to our ArcGIS Ideas site here.


    12 Maps That Changed the World

    In June 2012, Brian McClendon, an executive at Google, announced that Google Maps and Google Earth were part of a far loftier pursuit than edging out Apple and Facebook in the map services market. Google, McClendon wrote in a blog post, was engaged in nothing less than a "never-ending quest for the perfect map."

    "We’ve been building a comprehensive base map of the entire globe—based on public and commercial data, imagery from every level (satellite, aerial and street level) and the collective knowledge of our millions of users," McClendon noted. By strapping cameras to the backs of intrepid hikers, mobilizing users to fact-check map data, and modeling the world in 3D, he added, Google was moving one step closer to mapmaking perfection.

    It was the kind of technological triumphalism that Jerry Brotton would likely greet with a knowing smile.

    "All cultures have always believed that the map they valorize is real and true and objective and transparent," Brotton, a professor of Renaissance studies at Queen Mary University of London, told me. "All maps are always subjective. Even today’s online geospatial applications on all your mobile devices and tablets, be they produced by Google or Apple or whoever, are still to some extent subjective maps."

    There are, in other words, no perfect maps—just maps that (more-or-less) perfectly capture our understanding of the world at discrete moments in time. In his new book, A History of the World in 12 Maps, Brotton masterfully catalogs the maps that tell us most about pivotal periods in human history. I asked him to walk me through the 12 maps he selected (you can click on each map below to enlarge it).

    A 15th-century reconstruction based on Ptolemy's projections of the world (Wikimedia Commons)

    Al-Sharif al-Idrisi, a Muslim from Al-Andalus, traveled to Sicily to work for the Norman King Roger II, producing an Arabic-language geography guide that drew on Jewish, Greek, Christian, and Islamic traditions and contained two world maps: the small, circular one above, and 70 regional maps that could be stitched together. Unlike east-oriented Christian world maps at the time, al-Idrisi's map puts south at top in the tradition of Muslim mapmakers, who considered Mecca due south (Africa is the crescent-shaped landmass at top, and the Arabian Peninsula is in the center). Unlike Ptolemy, al-Idrisi depicted a circumnavigable Africa—blue sea surrounds the globe. Ultimately, the map is concerned with representing physical geography and blending traditions—not mathematics or religion. "There are no monsters on his maps," Brotton says.

    This map from England's Hereford Cathedral depicts "what the world looked like to medieval Christians," Brotton says. The organizing principle in the east-oriented map is time, not space, and specifically biblical time with Christ looming over the globe, the viewer travels spiritually from the Garden of Eden at top down to the Pillars of Hercules near the Strait of Gibralter at bottom (for a more detailed tour, check out this handy guide to the map's landmarks). At the center is Jerusalem, marked with a crucifix, and to the right is Africa, whose coast is dotted with grotesque monsters in the margins. "Once you get to the edges of what you know, those are dangerous places," Brotton explains.

    What's most striking about this Korean map, designed by a team of royal astronomers led by Kwon Kun, is that north is at top. "It's strange because the first map that looks recognizable to us as a Western map is a map from Korea in 1402," Brotton notes. He chalks this up to power politics in the region at the time. "In South Asian and Chinese imperial ideology, you look up northwards in respect to the emperor, and the emperor looks south to his subjects," Brotton explains. Europe is a "tiny, barbaric speck" in the upper left, with a circumnavigable Africa below (it's unclear whether the dark shading in the middle of Africa represents a lake or a desert). The Arabian Peninsula is to Africa's right, and India is barely visible. China is the gigantic blob at the center of the map, with Korea, looking disproportionately large, to its right and the island of Japan in the bottom right.

    This work by the German cartographer Martin Waldseemuller is considered the most expensive map in the world because, as Brotton notes, it is "America's birth certificate"—a distinction that prompted the Library of Congress to buy it from a German prince for $10 million. It is the first map to recognize the Pacific Ocean and the separate continent of "America," which Waldseemuller named in honor of the then-still-living Amerigo Vespucci, who identified the Americas as a distinct landmass (Vespucci and Ptolemy appear at the top of the map). The map consists of 12 woodcuts and incorporates many of the latest discoveries by European explorers (you get the sense that the woodcutter was asked at the last minute to make room for the Cape of Good Hope). "This is the moment when the world goes bang, and all these discoveries are made over a short period of time," Brotton says.

    The Portuguese cartographer Diogo Ribeiro composed this map amid a bitter dispute between Spain and Portugal over the Moluccas, an island chain in present-day Indonesia and hub for the spice trade (in 1494, the two countries had signed a treaty dividing the world's newly discovered lands in two). After Ferdinand Magellan's expedition circumnavigated the globe for the first time in 1522, Ribeiro, working for the Spanish crown, placed the "Spice Islands," inaccurately, just inside the Spanish half of his seemingly scientific world maps. Ribeiro may have known that the islands (which appear on the far-left and far-right sides of the map) actually belonged to Portugal, but he also knew who paid the bills. "This is the first great example of politics manipulating geography," Brotton says.

    Next to Ptolemy, Brotton says, Gerardus Mercator is the most influential figure in the history of mapmaking. The Flemish-German cartographer tried "on a flat piece of paper to mimic the curvature of the earth’s surface," permitting "him to draw a straight line from, say, Lisbon to the West Coast of the States and maintain an active line of bearing." Mercator, who was imprisoned by Catholic authorities for alleged Lutheran heresy, designed his map for European navigators. But Brotton thinks it had a higher purpose as well. "I think it’s a map about stoicism and transcendence," he says. "If you look at the world from several thousands miles up, at all these conflicts in religious and political life, you’re like ants running around." Mercator has been accused of Eurocentrism, since his projection, which is still occasionally used today, increasingly distorts territory as you go further north and south from the equator. Brotton dismisses this view, arguing that Europe isn't even at the center of the map.

    Working for the Dutch East India Company, Joan Blaeu produced a vast atlas with hundreds of baroque maps gracing thousands of pages. "He's the last of a tradition: the single, brilliant, magician-like mapmaker who says, 'I can magically show you the entire world,'" Brotton says. "By the late 17th century, with joint stock companies mapping every corner of the world, anonymous teams of people are crunching data and producing maps." Blaeu's market-oriented maps weren't cutting-edge. But he did break with a mapmaking tradition dating back to Ptolemy of placing the earth at the center of the universe. At the top of the map, the sun is at the center of personifications of the five known planets at the time—in a nod to Copernicus's theory of the cosmos, even as the earth, divided into two hemispheres, remains at the center of the map, in deference to Ptolemy (Ptolemy is in the upper left, and Copernicus in the upper right). "Blau quietly, cautiously says I think Copernicus is probably right," Brotton says.

    Beginning under Louis XIV, four generations of the Cassini family presided over the first attempt to survey and map every meter of a country. The Cassinis used the science of triangulation to create this nearly 200-sheet topographic map, which French revolutionaries nationalized in the late 18th century. This, Brotton says, "is the birth of what we understand as modern nation-state mapping . whereas, before, mapmaking was in private hands. Now, in the Google era, mapmaking is again going into private hands."

    Don't let the modesty of this "little line drawing" fool you, Brotton says: It "basically created the whole notion that politics is driven to some extent by geographic issues." The English geographer and imperialist Halford Mackinder included the drawing in a paper arguing that Russia and Central Asia constituted "the pivot of the world's politics." Brotton believes this idea—that control of certain pivotal regions can translate into international hegemony—has influenced figures ranging from the Nazis to George Orwell to Henry Kissinger.

    In 1973, the left-wing German historian Arno Peters unveiled an alternative to Mercator's allegedly Eurocentric projection: a world map depicting countries and continents according to their actual surface area—hence the smaller-than-expected northern continents, and Africa and South America appearing, in Brotton's words, "like long, distended tear drops." The 'equal area' projection, which was nearly identical to an earlier design by the Scottish clergyman James Gall, was a hit with the press and progressive NGOs. But critics argued that any projection of a spherical surface onto a plane surface involves distortions, and that Peters had amplified these by committing serious mathematical errors. "No map is any better or worse than any other map," Brotton says. "It's just about what agenda it pursues."

    The West Wing enshrined the Peters Projection in pop culture during an episode in which the fictitious Organization of Cartographers for Social Equality lobbies the White House to make it mandatory for public schools to teach Peters's map rather than Mercator's.


    Watch the video: Map Projections Explained - A Beginners Guide (January 2022).