700-1350 North American Southwest Desert, South America, Scandinavia, New Zealand and Alaska Analyses of bristlecone pines in the White Mountains of California, showed greater growth was recorded in the 11th and 12th centuries
(Leavitt, 1994). By analyzing 13C/12C ratios in the rings of these trees, it was also found that soil moisture conditions were more favorable in this region during the Medieval Warm Period (Leavitt, 1994). Simultaneous increases in precipitation were additionally found to have occurred in monsoonal locations of the United States desert southwest, where there are indications of increased lake levels from A.D. 700-1350 (Davis, 1994). Other data document vast glacial retreats during the Medieval Warm Period in parts of South America, Scandinavia, New Zealand and Alaska (Grove and Switsur,
1994; Villalba, 1994); and ocean-bed cores suggest global sea surface temperatures were warmer then as well (Keigwin, 1996a, 1996b). |
