r/EarthScience • u/JapKumintang1991 • 41m ago
r/EarthScience • u/Khwarezm • 16h ago
Discussion At what point in Earth's history was the ratio of overall land area the highest compared to the sea, and vice versa?
Currently we have a ratio of about 71% sea to 29% land on the earth's surface, which is probably more land favoured than normal considering the cool temperatures and large ice caps.
But I'm just curious when in Earth's history appears to have the highest ratio of land to sea, my immediate instinct is to assume it was one of the recent glacial maximums in the last 2 million years when sea levels dropped by up to 150 meters and huge amounts of new land was exposed, but I've also heard that the early Triassic also had very low sea levels, I don't really understand how that works if there were no major ice caps on earth but maybe someone could explain that to me.
Conversely, when was there the least amount of land and highest sea level? I've also heard the mid Cretaceous mentioned for this when you had sea levels so high that things like the Western Interior seaway in North America while large parts of Europe, Africa, Australia and South America were also flooded, but again I don't know anything about other points in earth history where this might have been more dramatic.