Mid-Holocene climate in Northern Minnesota
Study of Holocene ostracodes and diatoms from Elk Lake, in North-Central Minnesota, indicates that the local climate of the mid-Holocene can be subdivided into three intervals. Throughout interval 1 (ca. 7800 to 6700 yr B.P.), climate was colder and much drier than today. During intervals 2 and 3 (ca. 6700 to 4000 yr B.P.) average mean-annual air temperatures approached the modern mean (3.7??C), but warm summers persisted throughout interval 2, whereas during interval 3 warm summers fell into discrete episodes. Furthermore, average mean-annual precipitation was about 85 and 90% of modern during intervals 2 and 3, respectively. Transition times between the principal intervals were less than 50 yr. The expected effects of a retreating Laurentide Ice Sheet that initially maintained a winter-style circulation, followed by transitional climate states, and finally a near-modern circulation pattern may explain these local climatic events. ?? 1987.
Citation Information
Publication Year | 1987 |
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Title | Mid-Holocene climate in Northern Minnesota |
DOI | 10.1016/0033-5894(87)90064-0 |
Authors | R. M. Forester, L.D. Delorme, J.P. Bradbury |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Quaternary Research |
Index ID | 70014242 |
Record Source | USGS Publications Warehouse |