Imagine you are standing in a farm field in central Illinois. The land is so flat you can see for miles and miles. On a clear day, you might see a grain silo 20 miles away. You might think to yourself, it sure is flat around here. If you drive one hundred miles to the south, the landscape changes. In southern Illinois, there are rolling hills. Why do you think this is? What could have caused these features? There are no big rivers that may have eroded and deposited this material. The ground is capable of supporting grass and trees, so wind erosion would not explain it. To answer the question, you need to go back 12,000 years. Around 12,000 years ago, a giant ice sheet covered much of the Midwest United States. Springfield, Illinois, was covered by over a mile of ice. Its hard to imagine a mile thick sheet of ice. The massive ice sheet, called a glacier, caused the features on the land you see today. Where did glaciers go? Where can you see them today? Glaciers are masses of flowing ice.

Why does Springfield have its features?

Heat supplies the energy that causes motion. The deeper you go into toward the Earths core, the hotter it gets. At the core it is really hot. All that heat tries to rise toward the surface. In the Mantle, the rock is partially melted and is able to move. As it is heated, the material in the mantle moves toward the surface. As the mantle material rises, it cools. When it reaches the Earths crust, it is mostly stopped. A little of the material can break through the surface, but not all. Instead, it begins to move horizontally. The mantle material moves horizontally away from a mid-ocean ridge crest. Toward the surface, the mantle material starts to cool. As it cools it sinks back down into the mantle. These areas are where deep sea trench occur. The material sinks back down to the core. The system operates like a giant conveyor belt. The motion due to heating and cooling is called convection.

Which direction does the mantle move?

Dr. Benjamin Stone is a hotshot young surgeon who longs to leave the drudgery of a Washington , D.C. emergency room and finally leaps at his chance at more money and less death as a plastic surgeon in Beverly Hills . On his last day , Ben's relationship with his co-workers is presumed to be anything but a warm one . None of his colleagues will join him for a drink and a cake in his honor has an iced portion of the phrase '' Good riddance , asshole '' sliced out . Ben's cross-country drive in a 1956 Porsche 356 Speedster is interrupted when he crashes in the rural hamlet of Grady , South Carolina . The crash damages the fence of local Judge Evans , who sentences him to community service at a nearby hospital . Ben offers to pay for the fence , but the stern judge increases his community service each time he talks back . Defeated , he reports to the hospital , where Nurse Packer humbles him by ordering him to clock in and out , as would a factory worker . Though upset , Ben quickly makes friends with Mayor Nick Nicholson , the town cafe's proprietor/head waitress , and Melvin , the local mechanic tasked with repairing Ben's car . Ben soon finds his clinic work to be much more laid-back than the emergency room . He has simple cases such as spots before the eyes , fishing hook impalings , and even reading mail for a young illiterate couple , whose baby he later delivers . The experience also humbles Ben when he mistreats a case of mitral valve regurgitation leading to late cyanosis in the child .
Who has simple cases