Impassible tropics

In 1967, a group of American scientists started project eternal flame, in order to create nearly unlimited power, one Ascension Island. The device is extremely powerfull and if it would be just 1 nanometer out of sink it would cause a cataclysmic event.

1970: the fourth test of the Bhaskara machine, the machine is 3 nanometers out of sink and mere seconds after starting, the machine disintegrates creating an explosion of 50 kilotons of TNT, killing all the scientists. Creating a fireball 290m in diameter. But the explosion was not the real danger, a massive energy wave causes the ocean floor in the tropics to rise, the water evaporates or is absorbed by the ocean, only a little bit streams into the other oceans, causing a global rising is sea levels by only 12 cm. In a mere two hours the rest of the tropics are turned into a massive desert, killing all inhabitants and destroying every plant, city and animal. What remained was a massive dessert splitting the earth in 2, only realisticly passable with plane or helicopter.