More than 70% of the Earth’s surface is covered by waterfall: but what would our planet look like if this disappeared? NASA has provided an answer with an ad hoc model that illustrates the progressive disappearance of the oceans And the emergence of valleys, volcanoes and mountain ranges that are now underwater.
To create this map (whose vertical scale is exaggerated by 60 times) it was necessary to integrate data topographical with data bathymetric, representing the current mainland in grey and the new emerged areas in brown tones, where darker colours are associated with greater depth.
The first thing that catches the eye is that, as soon as the sea level drops of a few hundred meters, some signs begin to appear land bridges between continents, such as the one between Canada, Greenland and Northern Europe, or between the various archipelagos of Southeast Asia. Among other things, some of these bridges were used in the past by our ancestors to migrate from one continent to another. These are the words of the astronomer James O’Donoghue:
When the last ice age occurred, a lot of the ocean water was locked up as ice at the poles of the planet. That’s why there were land bridges. Each of these connections allowed humans to migrate, and when the ice age ended, the water sort of sealed them in.
Looking at the map you can also notice how underwater mountain ranges can be much larger and more extensive than terrestrial ones: for example, we are talking about the Mid-Atlantic Ridge which begins to be clearly visible after a loss of altitude of the water of 2000-3000 meters and which overall is almost as long 60,000 km.
The last areas to remain dry, as you can easily imagine, are the ocean trenches: these begin to be clearly visible with a sea level of 5000 meters lower to the current one and among these we find for example that of South Sandwich (between South America and Antarctica), that of Atacama (off the coast of Peru) or that of the Marianas which, given its incredible depth of 10.994 mwould be the last spot on the planet to be drained.
