Milankovitch calculated solar energy receipt during summer at 65°N for the past 600,000 years (also for 55° and 60°, but they are not shown here). The solid line shows variation in insolation relative to the present. A value of 70°, for example, shows that at that time in the past, summer insolation at 65° is the same as received at 70° today and, therefore, colder than the present. A value less than 65° represents warmer conditions than at present. At the time Milankovitch did his work, it was generally assumed that four glaciations had occurred in the Alps during the Pleistocene, named Günz, Mindel, Riss and Würm. The dashed line is Köppen and Milankovitch’s schematic estimation of these glaciations and intervening interglacials. Glaciologists have since determined that many more than four glaciations have occurred and that the Pleistocene is one to two million years old, not 600,000. (Adapted from Figures 48 and 49 of Milankovitch, 1941.)
Originally uploaded in CAMEL.
Image 62332 is a 400 by 600 pixel WebP
Uploaded:
Aug5 15
