This period was marked by rapid expansion of mountain [[glacier]]s, especially in the Alps, Norway, Ireland, and Alaska. There were three maxima, beginning about 1650, about 1770, and 1850, each separated by slight [[warming interval]]s. <ref> [http://earthobservatory.nasa.gov/Library/glossary.php3?mode=all NASA Earth Observatory glossary] </ref> | This period was marked by rapid expansion of mountain [[glacier]]s, especially in the Alps, Norway, Ireland, and Alaska. There were three maxima, beginning about 1650, about 1770, and 1850, each separated by slight [[warming interval]]s. <ref> [http://earthobservatory.nasa.gov/Library/glossary.php3?mode=all NASA Earth Observatory glossary] </ref> |