The world has actually had two drastically different geographies, because of the destruction during the Breaking, but the destruction seems to have radiated outward from Shayol Ghul.
The Breaking may not have been as cataclysmic in distant parts of the world.

A fourth continent may lie hidden beneath the massive ice of the southern polar regions, but it is unknown and likely to remain so.

Geographical Regions.

The Known World

• The Mountains of Dhoom,...they are , as suspected, a planetwide upheaval caused during the Breaking.
• ..volcanic mountain of Shayol Ghul, may once have been an island in a cool sea
• Fog shrouded valley known as Thakan'dar.

• Blasted lands, devoid of life, this land is even shunned by the foul creatures of the Blight.

  Historians believe that the area bore the brunt of the War of Power. No one knows if anything lies north of the Blasted Lands other than the frozen ice of the northern ocean, Jain Farstrider was said to have willingly travelled there - he vanished within its trackless depths.

• The Dragonwall, there are only four useful passes, and one southern route around these mountains.

  Tarwin's Gap. Niamh Passes. Jangai Passes. There is another nameless breach in the mountains, at the eastern edge of Haddon Mirk, south of where the River Iralell originates, leading only to the Ogier Stedding Shangtai.
  Mayene leads only to the Waterless Sand in the southern part of the Aiel Waste.

• The Drowned Lands are a huge treacherous saltwater swamp, a thick jungle of foliage interspersed with large shallows clogged by tall grasses.
  • Wide variety of flying and swimming creatures. Water lizards, very sharp teeth in powerful jaws.
  • Coloured birds, the nedar.
  • The soetam or great rat, that weighs ten stone.
  • Swamp cat.
  • Two types of very small deer, the spikehorn, which is little more than knee-high to a man, and the forkhorn which grows to waist height.
• East of the Drowned Lands and bordering the coast is the Termool or Waterless Sand. Even the Aiel do not travel there.
• The vast majority of the Waste is trackless lands and baked flats, with the occasional oasis or mountain range. Three small ranges are known to branch off from the Spine into the Waste.
• The Cliffs of Dawn run along the Northeast edge of the Waste, and are one hundred to five hundred feet in height.
• The rest of the eastern edge of the Waste is bordered by a massive split in the earth that ranges from one to three miles in depth. The Great Rift runs over hundred and fifty leagues from the end of the Cliffs of Dawn into the Sea of Storms. but the eastern side of the rift, away from the Waste, appears to have much more water.
• Morenal Ocean forms the eastern border of Shara.

Seanchan
Approximately fifteen hundred leagues wide at its greatest breadth. From the Mountains of Dhoom in the north to the southernmost point of the continent is a distance of approximately four thousand leagues.
Hawkwing's men named the northern region, The Lesser Blight, because they found the Blight in Seanchan less dangerous than their own.
Despite the Seanchan claims of having destroyed all Shadowspawn, a few creatures such as Draghkar can still be found within their Blight. Corruption is a less virulent form.
From the Mountains of Dhoom in the north to the southernmost point of the continent is a distance of approximately four thousand leagues.

Land of the Madmen
Nameless except to its inhabitants.
Approximately seven hundred and fifty leagues across and five hundred leagues from north to south.
It extends to within five hundred miles of the southern ice cap.
The natives apparently never recovered from the Breaking.
There seems no possibility of peaceful contact.

To my mind, this is one of the most ridiculous things in the entire book. I can't see a plot line developing there so why include this information at all ?
The place stinks. The idea that there was no recovery from the Breaking is simply unsound. I'm no sociologist, but really. In three thousand years, villages must grow into towns, towns into cities etc. The notion of total collapse seems especially stupid when you consider the earlier statement that the destruction radiated out from the Blight, and that the Breaking was less significant in other parts of the world. By that logic this continent was the part least shaken by the Breaking. Frankly I just don't believe a word of it.