Monday, June 29, 2015

One Hundred Years of Earthquakes


Kenneth Davis has been busy Visualizing One Hundred Years of Earthquakes. He has created three different maps from the data to show earthquake activity through time, a heat-map of all quakes over the last one hundred years and a depth map of the quake data.

The animated Torque powered map shows a marked increase in earthquakes after the 1950's. This isn't a result of more earthquakes but due to the ever increasing improvements in measuring and recording seismic activity.

The heat-map provides a neat overview of the fault lines in the tectonic plates and where those faults have caused the most seismic activity. The depth map reveals the geometry of subduction zones, where two tectonic plates are colliding and one plunges beneath the other.

Mapping Population Trends in Europe


Last week the German Federal Institute for Research on Building, Urban Affairs, and Spatial Development released a map showing how population has changed in Europe between 2001 and 2011. The BBSR Map of European Population Change shows where populations have increased and decreased throughout Europe.

The Berliner Morgenpost has now created an interactive version of the map using the same data. The paper's Where the Population of Europe is Growing – and Where it’s Declining map shows population growth in 119,406 municipalities from 43 European countries (including Turkey).

The map includes a number of snapshot analyses of interesting trends in the data. You can access these snapshots using the links beneath the map. You can also zoom in on the map and click on any of the 119,406 municipalities to view the percentage population change between 2001 and 2011 at the selected location.


The Washington Post has also published an interesting analysis of the BBSR population data. Their article on Where Europe is Growing and Where it is Shrinking provides some useful insights into the European population data. For example, the paper points out how in Poland there is a clear pattern of population growth in the suburbs around large cities.

The Best European Bird Maps

Belgium's birds are a lot like New York cabs.

Actually Belgium's birds are nothing like New York cabs - but they do have one thing in common - people can't stop mapping them. In America Chris Wong's taxi data has proved irresistible to mappers, European mappers however apparently can't get enough of LiveWatch INBO's Belgium bird data.

At the beginning of the month I posted a round-up of the Top Five NYC Taxis Maps. Now it's time for the best European bird maps.


Two Gull Migrations, by Liz Scott, is an animated map showing the movements of two Lesser Black-backed Gulls (Gull 719 and Gull 623) over one year. Using the map you can follow the migratory patterns of both birds over the course of one year.

Gull 623 seems to have a wider migratory pattern, flying down to Guinea-Bissau for the winter, whereas Gull 719 prefers the milder climes of southern Spain in the winter months.


LifeWatch's own maps have looked at the movements of the tracked birds over shorter time periods.

These maps include an intensity map of Eric, a Lesser Black-backed Gull, breeding in the colony of Zeebrugge. The map shows Eric's movements over two months, revealing his most visited locations, including his frequent day-trips to Bruges.

Using the same data LifeWatch also created a map showing Eric's paths for every day. In this map Eric's daily flight paths are colored by day to show how his flight pattern changed over the two months in question.


Lifewatch has also used CartoDB's Torque to visualize bird migration patterns over the course of two nights. In a series of animated CartoDB Torque powered maps Lifewatch Inbo has visualized the flight migration of birds on the nights of April 7-8, 2013.

Using CartoDB to Visualize How Far Birds Migrate in a Single Night uses data from the ROBIN bird radar detection system to simulate the trajectory of individual birds from Belgium and the Netherlands. In each of the maps you can view an animated simulation of the birds' migration based on the birds' airspeed and the wind conditions on the nights in question.


The EuroBirdPortal (EBP) is establishing a European wide data repository of bird sightings in order to model the distribution of different species of birds over time and space and to establish the migratory patterns of those species.

The EBP has released a demonstration map to visualize the week by week distributional patterns of 15 species of birds over four years. The map uses CartoDB's Torque library to animate the European wide sightings of the 15 species during 2010 to 2013.

The bird sightings map is accompanied by another map which animates climatic variables, so that you can compare the distribution of the different bird species to the annual changes in temperature and precipitation. Press play on the map and you can view an animation of the bird sightings across Europe for the selected year in the left-hand map. At the same time you can view an animation of precipitation or temperature records for the same period on the right-hand map.

Sunday, June 28, 2015

The Magnificent Maps of the Week


If you want a little help deciding which map projection you should use for your current map project then you should use this map Projection Wizard. The Projection Wizard was a clear winner this week with readers of Maps Mania. It was both the most read post and the most shared on social media.

This Projection Wizard allows you to select the extent of the map view which you are working with by outlining the area on a Leaflet map. Once you've highlighted your map bounds you can choose a distortion property (Equal-area, Conformal, Equidistant or Compromise).

The Projection Wizard will then suggest which map projection you should use depending on the extent and the distortion property of the map. The suggested projections are based on 'A Guide to Selecting Map Projections' by the Cartography and Geovisualization Group at Oregon State University.


This week I was also impressed with CartoNerd's method for highlighting large socio-economic differences between geographical neighbors.

We are all used to choropleth maps being employed as a way to visualize the socio-economic performance of countries around the world. Choropleth maps are a great way to provide a global picture of different socio-economic indicators. They can effectively provide an overview of which countries are performing better and which countries are struggling within a particular socio-economic indicator.

Socio-Economic Tectonics however employs a different method to visualize socio-economic indicators which, instead of providing an overview, highlights the areas of the world where there are glaring dissimilarities in socio-economic performance between neighboring countries. Country borders are used on the map to show socio-economic differences between adjoining countries. These differences are represented graphically on the map by the width of country borders. The wider the border between two countries then the bigger the difference in the selected socio-economic indicator.


I do like it when developers use online mapping libraries to create interactive image maps. One of the best non-cartographic uses of the Google Maps API is this Interactive Metabolic Pathways Map.

A metabolic pathway is a series of chemical reactions occurring within a cell. Each metabolic pathway consists of a series of biochemical reactions that are connected by their intermediates. The Interactive Metabolic Pathways Map allows you to explore all the metabolites, enzymes, and selected pathways.

What is particularly impressive about this image map of the metabolic pathways is that it is fully interactive and searchable. You can select any of the carbohydrates, amino acids, lipids or purines & pyrimidines on the pathways map to learn more about its role in the metabolic pathway. You can also search for any of the features by name to quickly locate them on the map.

24 Hours of Train Traffic in 60 Seconds


There has been a long tradition of using transit network timetables to create real-time transit map simulations. Vasile Coțovanu's Swiss Railways Network was probably the very first nationwide transit map which simulated train movements in real-time based on the network timetable.

Recently a new approach to mapping GTFS transit timetables has become popular. This new approach uses CartoDB's Torque library to provide a sped-up animated visualization of a tranist network. El Trafico de Trenes is a good example of this new trend.

Microsiervos has used Torque to visualize 24 hours of traffic on the Spanish rail network in just over one minute. Microsiervos has released two different maps. One shows an animated visualization of 24 hours of Spain's long distance trains. The other animates 24 hours of Spain's freight trains.


You can also view a simulation of one day of San Francisco's SFMTA bus network visualized on a map using CartoDB's Torque library. Danny Whalen's SFMTA Weekday Stop Times map animates all of San Francisco's buses over 24 hours in just 60 seconds.

If you want to create your own visualizations of a transit network then you might want to have a look at Vasile's Transit Map library. Vasile has also released the code for a GTFS (General Transit Feed Specification) plug-in as well. GTFS-viz converts a set of GTFS files into a SQLite database and the GeoJSONs needed by his Transit Map library.

If you want to create a sped-up version of a city's transit network then you should consider using the city's GTFS feed with CartoDB's Torque library.

Saturday, June 27, 2015

Mapping the Sale of Liquor


The sale of liquor in Vermont is controlled by the state’s Department of Liquor Control. There is obviously some debate as to whether the sale of liquor in Vermont should be privatized. However the fact that the industry is controlled by the state does mean that all the data surrounding the sale of liquor in Vermont is freely available.

Vermont's Seven Days has taken this data and created a map of Vermont's Best-Selling Liquor, Store by Store. Using the map you can click on any of Vermont's 80 liquor stores and discover the top 5 selling liquor brands.

The markers on the map seemed to be scaled by the volume of sales. So the larger the map marker the more liquor was sold in 2014. When you click on a marker you can also discover how the store ranks in the number of sales, the total volume of sales (in dollars) and the percentage of growth (from 2013).

I wish you could also query the map by liquor brand or by type of liquor. It would be nice for example, to see where vodka or whiskey was sold the most. The map could allow users to select a type of liquor and resize the map markers based on the volume of sales of the selected liquor type. However if you are interested in the top selling brands of liquor in Vermont Seven Days does have a chart of the top 10 selling brands in the state in this article.

Friday, June 26, 2015

Paint the Whole World with a Rainbow


Could there be a better way to celebrate Pride than to paint the whole world with a rainbow? Of course there could. The Supreme Court could legalize gay marriage in every state.

This weekend people across the globe will also be celebrating Gay Pride. The Pride rainbow colored flag will probably feature quite prominently in many of these Gay Pride events. In honor of these two events cartographers have also started painting the world with a rainbow.

Mapbox has started the party today with this Love Wins rainbow colored map. On this map the colors of the rainbow continuously scroll across the world. The map therefore not only celebrates the Supreme Court ruling but also acts as a neat little demonstration of how MapBox GL's vector map tiles can be updated in the browser on the fly.


If Mapbox's ever moving rainbow colors give you a headache then you can switch over to Amy Lee Walton's Love Wins map, which is a more serene rainbow styled map. Alternatively you could try Blake Thompson's Rainbow Roads map, which, as the name suggests, has rainbow colored roads.


If you don't like any of those rainbow maps then you might prefer my own Rainbow Map. This one has quite nice rainbow colored buildings.

Mapping the Transatlantic Slave Ships


Earlier this year Professor Adam Rothman  and Matt Burdumy of Georgetown University created a series of heat-maps using data from the Transatlantic Slave Trade Database to visualize 35,000 slaving voyages (from 1500 to 1870).

Their visualization of the Transatlantic Slave Trade Database consists of three animated heat-maps showing the cumulative frequency of slave ship points of departure, the principal ports where slaves were purchased and the principal ports where the slaves were sold.

During the animation on each map a cumulative heat-map appears, revealing the pattern of slave voyages over time. For example, the map of slave voyage departures reveals how Portugal and Spain's early dominance of the transatlantic slave trade was quickly overtaken by the emergence of British slave traders.


Slate has now also created a mapped visualization of the Transatlantic Slave Trade Database. Slate's Atlantic Slave Trade in Two Minutes animates the actual journeys of the slave ship journeys over 315 years.

The map visualizes the scale of the transatlantic slave trade over the centuries. It also reveals the patterns of the trade routes used and the destinations of the slave ships. The size of the ships on the map are scaled to represent the number of slaves on board. You can also click on each ship to find out which country's flag it sailed under and more about its role in the slave trade.

The Map Projection Wizard


If you want a little help deciding which map projection you should use for your current map project then you should use the Projection Wizard.

This map projection guide allows you to select the extent of the map view you are working with by outlining the area on a Leaflet map. Once you've highlighted your map bounds you can choose a distortion property (Equal-area, Conformal, Equidistant or Compromise).

The Projection Wizard will then suggest which map projection you should use depending on the extent and the distortion property of the map. The suggested projections are based on 'A Guide to Selecting Map Projections' by the Cartography and Geovisualization Group at Oregon State University.

A PROJ.4 link is provided next to each suggested projection, which opens a popup window with a PROJ.4 library. Once you've settled on your map projection you might want to check-out the Proj4Leaflet plugin for using projections supported by Proj4js with Leaflet powered maps.

Thursday, June 25, 2015

Mapping 40 Years of Global Terrorism


These two new interactive maps of global terrorism casualties (1970-2013), by David Johnson, provide insight into terrorism hot-spots around the world and the changing geography of terrorism over those 44 years.

The Global Terrorism Casualties map visualizes terrorism casualties around the world as a dot map. The concentration of dots in Northern Ireland, Pakistan, Afghanistan, Algeria, El Salvador and in other countries helps to emphasize some of the most political troubled locations in the last half-century. The dots on the map for each terrorist incident are sized by the number of causalities.

The same dataset is used in the Global Terrorism Heatmap. This map however adds a time element to the data. The CartoDB Torque library is used to animate the terrorism incidents by date, which provides a great visualization of terrorist hot-spots over time. For example, notice how in El Salvador terrorist casualties come to a halt in January 1992, after the end of the country's civil war.