Monday's Map Games

It's always a good idea to ease your way into the working week by spending a little time playing a fun map game. So let's start this Monday with Posio, a multi-player geography game.

Posio is very similar to a lot of other games built with interactive maps. You are given the name of a city and all you have to do is click where you think the city is on a map of the world. However what makes Posio really fun is that you get to pit your geographical knowledge against other players.

As ever you are awarded points based on how close you get to the correct location on each turn.

If you want to clone the game the code is available on GitHub.


If you still need some distraction from work then why not have a go at the Guardian's latest geo-quiz, Identify World Cities from their Running Heatmaps? In this little quiz you need to try and identify ten world cities from the GPS tracks of Strava joggers and cyclists.

For each question you get a map and three possible answers. All you have to do is click on the correct answer. It's that easy!

A Glimpse into Tokyo's Past

Retroscope is a fascinating insight into Tokyo's history glimpsed through historical aerial views of the city. This interactive map presents a collection of aerial views of the city dating back to 1945.

The map uses a magnifying lens control to allow you to view historical aerial imagery of Tokyo overlaid on a modern map of the city. You can also select to view a vintage 1880 map of Tokyo overlaid on the modern map.

One of the interesting details that the map reveals is the historical canal network in Ginza. The canals can be clearly seen in the 1880 map and the 1945 aerial imagery. However by the time of the 1961 aerial imagery nearly all the canals have disappeared from the city.

The magnifying glass effect used in Retroscope is published on GitHub (with no license details). Alternatively you can use the Leaflet.MagnifyingGlass plugin (available under a MIT license) to create a similar effect on a Leaflet.js map.

Maps of the Week - China

This Maps of the Week round-up has a distinct Chinese flavor. China's diplomatic and territorial pursuits in the South China Sea and in the Pacific have been explored this week in two well designed interactive maps.

China has provided over $1.9 billion in aid to Pacific Island countries in the last ten years. You can view how much Pacific Island countries have received in aid from China on this new interactive map from the Lowy Institute. Chinese Aid in the Pacific provides information on Chinese aid projects in the Pacific islands region since 2006.

The map uses scaled markers to indicate the amount of Chinese aid received by each Pacific Island country. The map sidebar also allows you to filter the amount of aid provided by type of aid and by the sector funded. If you zoom in on the map you can view details on the individual projects which have been funded by the Chinese, including details on the amount of aid provided and a description of each funded project.


The conflicting territorial and maritime claims of China, Taiwan, Brunei, Malaysia, the Philippines and Vietnam in the South China Sea continue to affect diplomatic relations in the region. The potential for oil and gas exploitation, conflicting fishing rights and the control of major shipping lanes means that there are major disputes over both maritime boundaries and the ownership of islands in the South China Sea.

The Center for Strategic & International Studies has mapped how governments in the South China Sea are using shipping vessels, traditionally used for maritime law enforcement, to reinforce their territorial claims in the Sea. In Are Maritime Law Enforcement Forces Destabilizing Asia? the center has mapped a number of incidents in which countries have used coast guard and other maritime law enforcement agencies to try to assert their sovereignty in the Sea.

Magical Musical Maps

Let the map be your instrument and the sounds of the city be your inspiration and muse. It's time for a little map music.

Cinco Cidades is a fascinating project documenting the soundscapes of Portuguese cities. The  Folk Songs Project has recorded the ambient sounds at a number of locations in five different cities in Portugal. Using the Cinco Cidades soundmap you can can select and mix together any of these recordings to create your own musical composition from the sounds of Portugal's city streets.

To add a sound to your mix just select a marker on the map and click on the 'add sound to mix' button. You can adjust the levels of your mix by using the volume control on each sound recording that you have added to the mix.

If you don't want to create your own mix then click on the 'Load Mix' link instead, where you can listen to mixes created and saved by other users.


Ohio has 88 counties. A piano has 88 keys. So obviously Ohio is a piano!

Cartogrammar has mapped each county in Ohio to a different piano key. This means that on this map Ohio is a Piano, where each Ohio county is one of 88 piano keys. The map has 'The Entertainer' already programmed in. So, even if you never learnt to play the Ohiophone, you can still listen to a composition played on the map of Ohio.

This map was made with a now deprecated version of the Google Maps API. Therefore the background Google Map no longer loads. However the map overlay still works and you can still play tunes on the Ohio piano.


The GBIG Soundscape is another interactive map which allows you to create a mix from recorded sounds. This map allows you to recreate the soundscape of different locations around the world by creating your own mix of bird and frog songs recorded at specific locations.

The Global Biodiversity Information Facility has recently started to add rich media (sound, images, and video) to their open global biodiversity records. GBIF Soundscape has created a Leaflet map which allows you to reconstruct the 'soundscapes' of particular regions around the world by mixing the various bird and frog sounds that can be heard in those regions.

Select a region from the map and you can listen to a mix of all the bird and frog sounds which have been added to the GBIF data records at that location. At each location you can listen to all the recordings playing at once or listen to just the bird or frog songs. You can also click on the 'random' button to listen to a random mix from that location's sound recordings.

Markers & Icons for Interactive Maps

Mapskin is a collection of scalable vector map icons which are available as an open source font. The collection includes a large number of icons, sorted by a number of categories, including 'controls', 'layers' and 'styling'.

You can add mapskin icons to your interactive maps by adding a link to the mapskin icon CSS style sheet on the mapskin CDN. Alternatively you can download and host the icons yourself. Once you have linked to the mapskin style sheet the icons can be scaled to any font size or screen. They can also be easily customized with CSS rules.


Another good source for map icons is Mapbox's Maki map icons collection. The collection includes 114 different open sourced map markers which can be used with your interactive maps.

Each icon in the Maki collection is available in two sizes, 11px by 11px and 15px by 15px, and can be downloaded in SVG format. The collection also comes with the Maki Icon Set Editor, which allows you to change the color and shape of the map icons so that they complement the design of your interactive maps.

Interactive map developers and designers might also be interested in the Maki Style Guidelines.


Yet another source for downloadable map icons is the Map Icons Collection. The Map Icons Collection includes over 1,000 different map icons in seven different styles. It is also possible to edit the colors of each of the map markers in the Map Icons Collection.

A fourth source for map markers is the Map Icons Designer. The Map Icons Designer includes 200 map icons which can be downloaded in PSD Vector Shape & PNG format.

The Solar Energy Potential of Your Home

Home owners in Northern Virginia can use a new interactive map from the Northern Virginia Regional Commission to determine the solar energy potential of their house. The map provides an assessment of the solar energy potential of building rooftops in the Northern Virginia region.

If you enter an address into the Northern Virginia Solar Map you can view an aerial view of your home overlaid with a thermal image overlay showing the potential for solar energy. If you click on a building on the map you can view details about the potential size of a solar PV array that can be placed on the roof and the potential electricity savings that you could make.


If you don't live in Northern Virginia you could try Google's Project Sunroof instead. This potential solar energy tool from Google also calculates how much sunlight your roof is likely to receive throughout the year. It can therefore help you make a more informed decision about whether you should install solar panels.

Enter an address into Project Sunroof and you can view an estimate of how many hours of sunlight your roof receives per year, the square feet you have available for solar panels and the estimated net savings you could make.

Project Sunroof currently works in nearly every U.S. state. If your state isn't on Project Sunroof yet it should be available in the coming months.

Territorial Disputes in the South China Sea

The conflicting territorial and maritime claims of China, Taiwan, Brunei, Malaysia, the Philippines and Vietnam in the South China Sea continue to affect diplomatic relations in the region. The potential for oil and gas exploitation, conflicting fishing rights and the control of major shipping lanes means that there are major disputes over both maritime boundaries and the ownership of islands in the South China Sea.

The Center for Strategic & International Studies has mapped how governments in the South China Sea are using shipping vessels, traditionally used for maritime law enforcement, to reinforce their territorial claims in the Sea. In Are Maritime Law Enforcement Forces Destabilizing Asia? the center has mapped a number of incidents in which countries have used coast guard and other maritime law enforcement agencies to try to assert their sovereignty in the Sea.

You can browse through the mapped incidents chronologically by using the timeline above the map or by using the 'previous' and 'next' buttons.


Back in 2014 Al Jeezera published a map examining the history of South China Sea Disputes. The map explores some of the historical hot-spots between China and its neighbors in the area since 1974. The map itself was created using Leaflet.js and the Knight Lab Story Maps library.

The Story Map template means that you can explore the map chronologically, using the forward and back arrows to progress through Al Jaeezera's mapped history of the region. You can also click on the map markers to jump to individual locations on the map.


One of China's key strategies in the South China Sea has been to build artificial islands and to transform reefs and rocks in the Sea into islands capable of housing air strips, military buildings and port facilities.

Last year the New York Times published a report on China's island building strategy in the South China Sea. What China Has Been Building in the South China Sea includes aerial imagery of some of these new islands, an account of how the islands are created and a map of some of the major territorial disputes in the Sea.

In July of this year an international tribunal ruled against China's maritime claims in the South China Sea in Philippines v. China.

The Center for Strategic & International Studies has mapped some of the key arbitration rulings by the tribunal, in the Arbitration Outcome Map. One of the key rulings of the tribunal is that only natural islands and islands that can sustain human habitation qualify to have 12 nautical miles of territorial waters and 200-nautical mile exclusive economic zones.

China does not acknowledge the tribunal and therefore refuses to abide by its ruling.

North Dakota's Oil Boom & Bust

Boom to Bust is a fascinating animated map visualization of the rise and fall of North Dakota's oil & gas industries. The map shows the amazing growth in North Dakota's oil & gas revenues beginning in 2006 and the subsequent fall in revenues since 2015.

The map animates through the years from 2006 to March 2016. The scaled circular markers on the map show the location of individual oil wells. As the animation plays out you can see the huge explosion in horizontal drilling and hydraulic fracturing in North Dakota. This is especially clear in the early years in the timeline.

I think the size of the markers on the map indicate the monthly revenues from each well. I assume it doesn't show the production rates of each well. The map sidebar explains that production rates have continued to rise. The smaller circles at the end of the timeline are therefore presumably to do with the falling oil prices in recent years.

The data on the map was animated with CARTO's Torque.js library. Torque visualizations often get a lot of criticism for being nothing more than flashing dots on a map. In Boom or Bust, however, the animated data is used really well to tell the compelling story of North Dakota's oil economy over the last decade.

Mapping the 2015 Hajj Crush

During last year's Hajj hundreds of pilgrims were crushed to death in Mecca. The Hajj is the largest annual gathering of people in the world. The large increase in pilgrim numbers over the last two decades has resulted in a number of tragic accidents and crushes which have resulted from the overcrowding.

The New York Times has published an interactive account of last year's tragic events, told from the perspective of Rashid Siddiqui, a survivor of the crush that led to so many deaths. This account includes a story map which visualizes the route of Rashid's pilgrimage, the location of his tent, the route he took to the Kaaba and the site of the crush.

As you scroll through the Times' How One of the Deadliest Hajj Accidents Unfolded the map zooms in and pans to highlight various locations in Rashid's journey. The map itself consists of an aerial view of Mecca, overlaid with place labels and colored polygons showing where pilgrims from different parts of the world camp. The map attempts to explain some of the events on the ground which led to the tragic crush, near the intersection of Street 204 and Street 223, which caused so many deaths.

The China Aid Map

China has provided over $1.9 billion in aid to Pacific Island countries in the last ten years. These loans have helped Pacific Island countries in many ways, for example in helping to build important infrastructure such as hospitals and roads.

Much of China's aid in the region, however, has been in the form of concessional loans. Concessional loans can be a great way for counties to raise money on generous terms, although they do of course come with a degree of diplomatic and political indebtedness. Especially if a country subsequently struggles to repay the loan.

You can view how much Pacific Island countries have received in aid from China, how that money is being spent and how much of the aid is in the form of concessional loans on an interactive map produced by the Lowy Institute. Chinese Aid in the Pacific provides information on Chinese aid projects in the Pacific islands region since 2006.

The map uses scaled markers to indicate the amount of Chinese aid received by each Pacific Island country. The map sidebar also allows you to filter the amount of aid provided by type of aid and by the sector funded.

If you zoom in on the map you can view details on the individual projects which have been funded by Chinese aid, including details on the amount of aid provided and a description of the funded project,