The Oceans of Mars and this Dammed Earth

This interactive Mars Map includes an intriguing "ocean simulation" layer that allows you to explore how liquid water might once have carved the Martian landscape. By toggling the "ocean simulation" option in the map layers menu, an adjustment panel appears that allows you to manipulate the theoretical sea level across the planet’s unique topography. It’s a fascinating way to visualize where water would pool if Mars still possessed an atmosphere and climate capable of sustaining a liquid state.

Technically, the simulation functions as a dynamic topographic filter. As you adjust the slider, the map references Martian elevation data to "flood" every coordinate falling below your chosen threshold with a coordinate-specific color fill. The result is an instant, visual reimagining of the map of Mars, transforming the low-lying northern plains into a vast, deep-blue Oceanus Borealis.

You can even view a Street View simulation of a lake on Mars. Freie Universität Berlin's Jezero Crater interactive map allows you to take a virtual tour of the landing site on Mars of the 2020 Perseverance rover. This tour includes a synthesized 360 degree panorama of the crater as it might have once looked, when water still existed on Mars. 

The trick of using elevation data to determine where water might pool and flow is also used by other interactive maps, such as Climate Risk's Coastal Risk Map (which uses elevation to simulate rising sea levels) and the impressive River Runner Global (that allows you to virtually drop a raindrop anywhere in the world to visualize its journey to the sea).

Elevation data is also used in Inundator - Interactive Reservoir Inundation Visualization. The Inundator application is a sophisticated environmental modeling tool designed to simulate reservoir formation and dam breach scenarios on Earth.

You can have a lot of fun with this map trying to see how many towns and villages you can flood in the Alps simply by building a large wall across a valley.

Draw a line across a valley or river and the map immediately goes to work, fetching high-resolution Digital Elevation Model (DEM) data for that specific area. The system samples points along your path to establish a maximum Crest Elevation, triggering a flood simulation that 'pours' virtual water into the landscape. By filling every adjacent terrain cell lower than the dam’s height, the tool provides an instant, data-driven visualization of your dam's impact on the surrounding environment.