Wegener's theory of continental drift was largely dismissed by the mid-1900s. what new evidence was able to revive this theory, and why? continental ridges were found, suggesting that parts of the land used to be below sea level. sonar technology found mid-ocean ridges, where new ocean floor was being created. the coastlines of south america and africa were similar in shape, suggesting that they shared a common tectonic plate. the mantle moves through radiation, suggesting that rock in the earth is not solid.