Also, volcanic debris and heavy cloud cover shielded the earth's surface from much of the Sun's rays. Large temperature differences between the cold land and warm oceans generated high winds that rapidly transported moist air up onto the elevated, cool continents where heavy snowfall occurred, especially over glaciated areas. Many volcanoes on the ocean floor grew up to the surface of the lowered ocean, where their peaks were eroded and flattened by wave action. These flat-topped, truncated cones are now called tablemounts . Glaciers also melted and raised sea level.
Glacial retreat continues today.