Category Archives: Earth Sciences

Science Review of Deserts

Overview Desert lands generally receive less than 10 inches of rainfall per year, and sometimes receive no rainfall in a year.  Desert climates may be hot or cold, and the topography may be flat or mountainous. Polar Desert The continent of Antarctica is considered a polar desert.  It receives less than 8 inches of rainfall […]

Science Review of Glaciers

Overview Glaciers form on land when the amount of snow falling in winter is greater than the amount that melts in the summer.  The compact snow and ice form sheets that flow under their own weight.  Those moving rivers of ice are especially found in mountainous areas and in the polar regions on Earth. Types […]

Science Review of Ground Water

Overview Not all water on Earth exists in lakes, rivers, and seas. Some water can be found underneath the surface of the Earth as ground water. Ground water is an important source of water for plants and irrigation. The Water Table Most soil, sediment, and sedimentary rock such as sandstone, is porous, so that rain […]

Science Review of Floods and Flood Plains

Overview Large river systems and smaller rivers and streams often flood as a result of heavy rains and snowmelt. Land is submerged as the water level rises above its normal value and overflows its banks, so that water is over land that is usually dry. The 100-Year Flood Many streams flood regularly, but the water […]

Science Review of Streams and the Water Cycle

Overview Fresh water on Earth can be found in rivers, streams, lakes, and underground reservoirs. It is a small but important percentage of all water, since over 97 percent is seawater. The water cycle is the process of water circulation from the surface to the atmosphere and back again. Characteristics of Streams Streams are created […]

Science Review of Weathering and Erosion

Overview Surface processes such as weathering and erosion transform mountains and other landforms. Rocks and minerals disintegrate into sediment, and it is transported into other areas, building up new landforms. Mechanical Weathering At the surface, rocks and minerals crumble into smaller pieces from a variety of forces. Many of these forces, known as mechanical weathering, […]

Science Review of Mountain Formation

Overview Mountains form as a result of intense tectonic forces. Mountain chains such as the Andes and the Himalayas rise from the collisions of continental plates, as rocks are folded, uplifted, and faulted. Mountains Mountains have peaks that are at higher elevation than the surrounding land. The definition of a mountain usually includes the height […]