For me, one of the most appealing aspects of studying the earth sciences were maps. I know that might sound slightly odd, but maps have always fascinated me. The ability of them to let you make sense of spatial data is incredible. A lot of effort (and textbooks) have been put out to explain how to best pull apart data using graphs, but you see a lot less published on how to best visualise data in map form.

One of the trends I have noticed recently are, more and more, esoteric visualisation using maps. These have arisen because of both the increasing quality and freer availability of GIS and cartographic tools has made them easier and simpler to make, and the internet has been an excellent platform to share these maps. For a lot of people, who are used to maps only in street directory form, some of these visualisations are hugely surprising and that means people are interested in seeing them.

Below, I point out some of my favourite slightly oddball maps in a celebration of map making. If you have any of your own examples, share them in the comments as well.

The picture below is the closest pizza chain in a 10 mile radius across America: read more below for details and pulling out trends from a map like this.

Map of pizza chains across the USA
Map of pizza chains across the USA

The latest interesting map to come through my inbox is the one above: a map of pizza chains across the USA (http://flowingdata.com/2013/10/14/pizza-place-geography/). This is measured as the closest pizza place within a 10 mile (16 km) radius. There are some spatial trends in this map that you might not expect, though picking out the trends is more difficult. The most cunning way shown by the authors is to use a matrix style display, looking at which of two different pizza chains is closer. This is a particularly elegant way to look at it, and highlights the spatial trends much more clearly:

Matrix depicting which of two pizza chains is closer. Highlights the different spatial distributions of chains in the USA
Matrix depicting which of two pizza chains is closer. Highlights the different spatial distributions of chains in the USA

Another nifty map showing trends is a map of European languages with the country borders also shown. This shows the huge diversity across Europe. While it can’t highlight all of the subtleties, it does show how complex this part of the world is.

The dominate languages across Europe. Source unknown.
The dominate languages across Europe. Source unknown.

Speaking of languages, my favourite is to hop back to the USA and look at the different dialects across the USA (http://spark.rstudio.com/jkatz/SurveyMaps/). There’s so much detail in that link that it’s better to look at some of the better trends and their explanations (http://www.businessinsider.com.au/22-maps-that-show-the-deepest-linguistic-conflicts-in-america-2013-6). My favourite is probably the clearest trend: how to address groups of 2 or more people:

Map showing how the dialect changes across the USA. Source: http://spark.rstudio.com/jkatz/SurveyMaps/
Map showing how the dialect changes across the USA. Source: http://spark.rstudio.com/jkatz/SurveyMaps/

Another fancy map trend that’s been growing has been an increasing use of animation to depict spatial and temporal trends all together. One that did the rounds last year is a time lapse of European borders and how they have changed across the last ~1000 years: http://www.huffingtonpost.com/2012/05/16/europe-history-time-lapse_n_1520724.html. The video in that link is well worth a look: http://www.liveleak.com/view?i=f54_1337075813.

Turning to politics, there was an excellent discussion prior to the Australian federal election about how to illustrate electorate maps (http://www.theguardian.com/world/datablog/2013/sep/06/better-election-results-map). People might be familiar with the American electoral maps (the best are http://www-personal.umich.edu/~mejn/election/2012/) where areas are scaled according to population rather than geography, but that doesn’t work as well in Australia.

Depiction of Australian Federal Election results for 2010, scaled by spatial area and population of electorate. http://www.theguardian.com/world/datablog/interactive/2013/sep/06/australian-election-sized-by-population
Depiction of Australian Federal Election results for 2010, scaled by spatial area and population of electorate. http://www.theguardian.com/world/datablog/interactive/2013/sep/06/australian-election-sized-by-population

The best way to see how the population warping from a map to a cartogram works is to look at the interactive version: http://www.theguardian.com/world/datablog/interactive/2013/sep/06/australian-election-sized-by-population.

This particular representation is difficult in Australia, because Australia is a vast place with few people scattered in only a few places. This map, often used to illustrate the relative size of Australia for tourists, shows this perfectly:

Comparison of the size of Australia and Europe (source unknown)
Comparison of the size of Australia and Europe (source unknown)

One of the other boons for map making and visualising more esoteric spatial data is the rise and rise of web mapping services, especially Google maps. Unfortunately the site couldn’t handle the load on election day 2013 but my favourite this year was http://www.electionsausagesizzle.com.au/ which let you find polling stations but also let them submit what they had. Personally democracy is slightly easier to deal with after a coffee so finding somewhere with coffee was important for me. The map let me find somewhere close enough to where I live, but wouldn’t have been where I would have normally voted. A win for internet mapping.

Speaking of Google and the rise of internet services, the final map I’ll leave you with is one depicting the internet empires: the most visited site for each country, scaled by ‘internet population’. More details are at the original site (http://geography.oii.ox.ac.uk/2013/09/age-of-internet-empires/).

The top internet site visited by each country, scaled by the population of internet users: http://geography.oii.ox.ac.uk/2013/09/age-of-internet-empires/
The top internet site visited by each country, scaled by the population of internet users: http://geography.oii.ox.ac.uk/2013/09/age-of-internet-empires/

There’s a bunch more out there, but I didn’t want to make this post too long-winded. Share any of the cool maps you’ve discovered in your travels in the comments!