Ocean Chlorophyll Cartogram

This map is a gridded cartogram projection of chlorophyll concentration in the the world’s oceans.


Now it’s Your Turn

In the comments, please ask questions or make suggestions that will help the cartographer improve the map. Key things to think about include:

  • Does the map orient the viewer?
  • Does the data tell a story?
  • Does the map support the story being told?
  • Does the map make assumptions?
  • How could the map be more readable?
  • Are there any errors or typos?
  • Daniel

    This cool Hennig creation speaks volumes, and maybe requires no legend at all. however, it would be interesting to enumerate some of the factors of chlorophyll depletion, especially in areas of pronounced depletion as the Great Lakes, Mediterranean and Eastern US seashore, and to suggest whether the areas of pronounced chlorophyll concentrations (Baltic seas; Alaskan waters; Hudson Bay) have in fact declined in concentration historically. Beautiful cartogram, Ben!

  • Lois Paul White

    This dynamic map visually projects the world’s ocean chlorophyll content as a continual fluctuating organism as opposed to a static data percentage. The warp and weave of the continents show spatial movement. Since dark blue and black are non contrasting colors, at first glance, the disintegrating chlorophyll vs. the high content chlorophyll areas appear the same. Integrating a contrasting color such as phylo green or fluorescent yellow green would help viewers immediately distinguish the areas of least chlorophyll concentration. I enjoy how this map reads like an undulating fabric pattern. It is different from conventional maps. For scientists and cartographers that are innately aware of geographical sites on this planet, locating the areas of significantly increased chlorophyll areas is easy. To make it easy for the average spatially challenged map viewer, a faded out projection of the Earth’s continents in the background would provide a visual reference to the change in area mass that is being indicated in the grid cell rasterized calculations.

  • Xander Lenc

    This is a gorgeous cartogram! I have a few suggestions:

    – The bar of white space between the map description and the map itself breaks up the page layout awkwardly. I think it should be filled somehow, probably by reformatting the description and adding a visual legend.

    – It’s hard to get a sense of how much variability in chlorophyll concentration is being shown. I think a legend would help a lot. Perhaps you could have a bar showing how size represents the full gradient of concentration.

    – Sentences like “The absolute concentration was calculated for each grid cell in an equally-sized raster covering the sea areas only” might tell other cartographers and GIS technicians how you made your map, but it uses technical terminology that will even confuse many oceanographers, and most people are less interested in how you made your map and more interested in what it means. Scale bars, size-coded legends, and other visual aids help readers interpret your map better than this description, which I would just scrap.

    – Instead of your current text, I would add some data interpretation! Why is oceanic photosynthesis important? Most people have no idea that some plankton play a role in photosynthesis! Why are there low concentrations of algae and other photosynthetic organisms in midoceanic areas? Are some regions biological ‘dead zones’ due to climate change or other anthropogenic activity?

    – I think you need a new title! Most people who know what a cartogram is are cartographers, and they won’t need you to identify it as a cartogram in the title. I’d recommend a title that asks a question that you hope that this map answers or even poses, because as it stands this map lacks a strong narrative or message.

  • Caitlin

    Great job!

  • Corina Chung

    This is a really cool map! I like how this cartogram is about the oceans when cartograms are so often focused on land mass to represent pop size.

    My main suggestion is to make this map’s text more lay friendly; the text is very much in cartographer jargon. My only other suggestion is to do something with the white space in between the source and map description. I do like how the text sits below Antartica, so that there’s a seamless transition from map to text, but the white space should probably be filled in. I would also consider putting the description above the source and author credits.

  • Chris M

    Cool, glad to see a cartogram in the mix. Agree with all points below, including the title suggestion & re-placement of the description text.

    I would like to see a bit more contrast in the black to blue, maybe use a different shade of blue instead of such a dark one?

  • maybe add another map showing fishing catches or oxygen production? Hard to see a reason to care on this…