the.com/ice ages
earth's mood swings, each one lasting long enough to reroute rivers and species alike.
means long periods when global temperatures drop enough for ice sheets to expand across continents, reshaping climate, sea levels, and life itself.
from from geological evidence of glacial scarring across continents, first seriously proposed by louis agassiz in 1837 when he realized boulders in the alps had been dragged there by ice, not floods.
cycle driverearth's orbital wobbles, called milankovitch cycles
last one endedabout 11,700 years ago, roughly
sea level dropup to 400 feet during peak glaciation
we're technically in oneantarctica still has permanent ice sheets