Imagine that some kind of catastrophic event takes place on Earth, like a gigantic eruption, and half the planet ends up transformed into a hell-like hemisphere, with volcanoes and seas of lava (like Mustafar from Star Wars).
At some point, the lava would solidify forming an enormous range of volcanic rock mountains surrounding the equator, dividing the world in two defined halves. I guess that this ring would be impassable due to the high temperatures (and maybe poisonous air?) and people wouldn't even dare to get close to it.
How would this affect to climate? I've been thinking about oceanic currents, global winds, atmosphere composition, tectonic plates movement... And of course, what would be the ecosystems be like? Would we still have the same biomes with the same vegetation and fauna?
I've been chewing on this for a while and I would like what you guys think about this. Thank you very much!
OK, my bad. I've asked something too broad and big. I appreciate the feedback though. Let me fix this up a bit.
I know for sure there would be a massive extinction and the Earth would be an uninhabitable planet for eons. Please, don't focus so much on what would happen immediately but on a very, very long term (once the planet had been recovered). I think of this catastrophe as an event which has taken place in an very remote past, which no one is really aware of (since, as I posted before, people wouldn't dare to get close to the Equator), and which has reshaped the world completely.
But my major concern is the climate. I'd like to build a world with a consistent science-based explanation for its climate. I don't buy that "North is cold, South is hot" trope (I know I'm talking about southern hemisphere but please remind that cardinal direction is arbitrary). As far as I know, winds are just air currents moving between areas of different pressures, which are caused precisely by heat. One example of this is the monsoon, which I think is a really cool phenomenon.
Summing up: what would be like the climate of a planet whose southern hemisphere is a giant crater of lava. Would a single hemisphere climate system be viable? Would it be something similar to our current climate?
Thank you very much and, once again, excuse me for my broad question. My fault completely. Or maybe my question is just plain dumb. Sorry in any case.