Benedikt Groß

Speculative Sea Level Explorer

2013 Apr

A while ago, I have had to do a rough simulation for the sea level of the coast of England. Simulation in the sense of, how would the coastline and the territory of Lincolnshire (a county in the east of England) be reshaped approximately by a rise or decline of the sea level due to Global Warming?

While I was trying to figure out how much of Lincolnshire would remain for instance in the case of +6m sea level rise, btw. not that much, I realised that I was very drawn to simulate values beyond “normal” predicted Global Warming sea level projections. As I consider myself a non morbid person, it is safe to rule the voyeurism for catastrophes out. It is the notion of imagine the implications of such transformed/speculative landscapes, which intrigues me.

Because I really enjoyed to browse this “alternative” worlds, I decided to revisit the project to create a series of animations of various “dramatic” changes of a world reshaped by a monumental rise or decline of the sea level. All animations below have been created with the “Speculative Sea Level Explorer” application. The app (+ source code) is available for download at the bottom of the page, so you can start with your own explorations right away.

When I showed the animations to others, I was asked quite a few times whether this simulation is accurate? Short answer is “yes” in a rough way, especially for the large scale changes like the ones I am showing in the animations. The simulation is based on an elevation data set called “SRTM30 Plus” by the Scripps Institution Of Oceanography, which is an extended version of the original NASA Shuttle Radar Topography Mission (often abbreviated SRTM, land elevation only) enhanced with bathymetry (underwater evaluation). But there are also many limitations e.g. the cost region of the Netherlands is obviously wrong (it is on a rise of “+0″ already coloured blue). Altogether it is just a very basic and rough simulation based on the raw elevation, anything else is not put into consideration.

The Speculative Sea Level Explorer App runs on OSX, Windows and Linux. You can download a zip-file which contains the plattform specific application e.g. “application.macosx.zip”. Source code and the zip files are available on Github.

Inside the github repository there is a SRTM-file for central europe, see “data/w020n90.Bathymetry.srtm”. Run the app and press the “Load SRTM File” button to load the SRTM-file to get started. You can download other SRTM tiles for the rest of the world at the website of the Scripps Institution Of Oceanography. With the interactive map below you can lookup the filenames. Please note, the SRTM files around the Antarctic currently don’t work correctly.

The app has the following few sea level change presets:

• +4 to 6 m – Melting of the Ice Sheets
• -60m – Early Holocene
• -130m – Last Glacial Maximum
• +150m – The Hunger Games¹: “There would still be a civlization, but with much hardship and a much smaller population on a smaller continent, after the ice caps melt and the sea moves in.”
• +1000m – Waterworld¹: “The polar ice caps have completely melted, and the sea level has risen many hundreds of meters, covering nearly all the land”

¹my estimations, no hard numbers available.