Large rocks deposited by melting glaciers are called "glacial erratics," after the Latin word "errare" or "to wander." Erratics can be carried hundreds or thousands of miles by a glacier before they are deposited.
Because it is not difficult to determine the origin of most rocks, glacial erratics are very useful for determining the prehistoric flow of glaciers. Another type of erratic, a drop rock, is deposited on the ocean bed by a floating glacier; these erratics are helpful for determining prehistoric ocean conditions such as water temperature and currents. Smaller rocks, gravel and clay sediments dropped by glaciers are also useful in determining facts such as the farthest extent and the height of prehistoric glaciation.Learn More
Avalanches occur when large amounts of snow fall from steep slopes, either due to a break or fissure in the snow pack or due to an accumulation of too much snow for the slope's angle. In some cases, a snow pack can fracture due to a hiker or skier's actions, or rising temperatures may render the accumulated snow too unstable to stick to the slope.Full Answer >
The solar radiation that heats the Earth's crust is the driving force behind the water cycle. The water cycle is sometimes referred to as the hydrologic cycle and is a process through which Earth's water continuously moves between the surface of the planet and the atmosphere.Full Answer >
Mass movement is the bulk movement of rock and soil debris down a slope in response to gravity or the sinking of the Earth's surface in a vertical direction. This process may also be referred to as mass wasting.Full Answer >
According to the NSRC Science and Technology Concepts for Middle Schools, convection currents in the ocean are convection cells that contain warmer water. These cells move along the surface of the water to deeper cold water and poles that flow in the direction of the equator.Full Answer >