<a href="https://en.wikipedia.org/wiki/Northern_Hemisphere" class="extiw" title="en:Northern Hemisphere">Northern Hemisphere</a> glaciation during the last <a href="https://en.wikipedia.org/wiki/ice_ages" class="extiw" title="en:ice ages">ice ages</a>. The accumulation of 3 to 4 km thick ice sheets caused a sea level lowering of about 120 m. Also, the Alps and the Himalayas were covered by glaciers. Winter sea ice coverage was much more limited in the south.
<a href="//commons.wikimedia.org/wiki/User:Hgrobe" title="User:Hgrobe">Hannes Grobe</a>/AWI
CC BY 2.5
own work - redrawn, supplemented and modified grafic from <a rel="nofollow" class="external text" href="https://pubs.usgs.gov/gip/continents">John S. Schlee (2000) Our changing continent, United States Geological Survey.</a>