[DB 1516 (82)] The weight of a glacier, or sometimes a deep lake, can form a depression in the Earth after only a few thousand years (the Earth's mantle has a viscosity much greater than "Silly Putty" but exhibits similar properties over timescales of several thousand years or more). Raised shorelines in Canada, Scandinavia, and Utah came about when such a depression was followed by removal of the weight because the glacier melted (or, in Utah's case, Lake Bonneville was drained). The depression then slowly rebounds, much like a depression made in a bowl of Jell-O will rebound after several hours. The rate of uplift, and thus the viscosity of the mantle, can be calculated by using various methods to date the shorelines, and the results are consistent around the world (adding to their credibility). Furthermore, shorelines near the center of the formerly depressed areas are now raised much higher than shorelines near the edges. This is expected from the isostatic rebound model, but it is inexplicable to the "Flood Geology" hypothesis, which assumes that all of the shorelines are vestiges of a single high water level.