Benedikt Groß profile image

Works antidisciplinarily, is a speculative and a computational designer.
He currently lives in Ravensburg / Stuttgart.

Speculative Sea Level Explorer

tagged as:


Concept + Idea: Benedikt Groß
Elevation Data: “SRTM30 Plus” by Scripps Institution Of Oceanography, San Diego
Map Color Palette: Hypsometric scheme based on, Ísland by Konstantin Käfer and
Carte physique et géographique de la France by R. Leuzinger
Hillshading: based on hillshade.cpp by Matthew Perry
Developed With: ProcessingunfoldingcontrolP5


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 in not put into consideration.

Legend (meters above sea level)


+/-500m / 2m steps


+/-1000m / 5m steps


+/-1000m / 5m steps


+3600m / -6000m / 30m steps


+/-1000m / 5m steps


+/-1000m / 5m steps


+/-1000m / 10m steps

Download – Speculative Sea Level Explorer App

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. “”. Source code and the zip files are available on

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 a few sea level change presets, like the following ones:

  • +4 to 6 m Melting of the Ice Sheets
  • -60m – Early Holocene
  • -130m – Last Glacial Maximum
  • +150m* – The Hunger Games
    “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* – Waterworld
    “The polar ice caps have completely melted, and the sea level has risen many hundreds of meters, covering nearly all the land”

*my estimations, no hard numbers available. Does anyone have other interesting numbers? If so please drop a note!

Please note, the app is a rough sketch, don’t expect a super sophisticated piece of software. It is basically just the tool is used to produce the animations, I never had the intention to make an app out of it in the first place. Nevertheless I still think it is worth to share it. Feedback is welcome!

SRTM30 Plus Tiles

All SRTM30 Plus tiles courtesy of Scripps Institution Of Oceanography, San Diego, USA.