How much higher or lower was the sea level in the early Pliocene compared to today ?
During the Pliocene the earth climate system response shifted from a period of high frequency - low amplitude oscillation dominated by the 41,000 year period of Earth 's obliquity to one of low frequency - high amplitude oscillation dominated by the 100,000 year period of the orbital eccentricity characteristic of the Pleistocene glacial - interglacial cycles .