What happens if a major Internet artery is cut off?

What happens if a major Internet artery is cut off splitting the Internet service between North America and Asia which then causes the mined blocks to diverge between both continents?

Will each chain continue to be mined as if nothing happened but their data will be different?

What happens if the Internet connection resumes after 20 minutes and what if the Internet connection resumes after 2 days?

What if the artery was not completely cut off but there remained a slow and throttled connection between both continents connected by a weak satellite?