Once again, plate tectonics is shown to be involved in the process. Weathering and Soils The Cleopatra's Needle obelisk in New York City's Central Park is severely weathered after only 75 years, whereas the dry climate of Egypt has preserved similar structures in that country for millennia. Mass Wasting Anyone undertaking a building project must understand mass wasting the downslope movement of earth under the influence of gravity.
This program shows how weather, climate, chemicals, temperature, and type of substrate factor into rock and soil erosion. Various factors in mass wasting, including the rock's effective strength and pore spaces, are discussed, as are different types of mass wasting such as creep, slump, and landslides.
This program looks at the variety of minerals, their atomic and crystalline structures, and their physical properties such as hardness and luster.
Petrologists' methods of sectioning rocks are shown, and gems, precious metals, ore excavation, and the value of silicates are discussed. Volcanism Volcanoes provide clues about what is going on inside Earth. Intrusive Igneous Rocks Most magma does not extrude onto Earth's surface but cools slowly deep inside Earth.
The relationship of metamorphic rock to plate tectonics is also covered. Running Water I: Rivers, Erosion and Deposition Rivers are the most common land feature on Earth and play a vital role in the sculpting of land. Running Water II: Landscape Evolution The Colorado River is a powerful geologic agent powerful enough to have carved the Grand Canyon.
This program shows landscapes formed by rivers, the various types of rivers, the basic parts of a river, and how characteristics of rivers their slope, channel, and discharge erode and build the surrounding terrain. This program focuses on how such carving takes place over time, looking at erosion and deposition processes as they relate to river characteristics and type of rock.
Geophysicists use seismic wave studies, variations in temperature, magnetic fields, gravity, and computer simulations to create models of deep structures. The Sea Floor The mysteries of the ocean floor lie hidden under enormous pressure and total darkness.
This program looks at the research submersibles and indirect methods used to study the bottom of the sea, providing a glimpse of volcanic activity, formations such as the continental shelf and mid-ocean ridges, and life forms that thrive at extreme depths. The Birth of a Theory In the 1960s, earth scientists developed the theory of plate tectonics.
This program examines the traces left by early plants, animals, and single-celled organisms and follows the progression of life forms over time.
Connections are drawn between atmospheric gases, climate change, rock formation, biological functions, and mass extinctions. Minerals: The Materials of Earth Minerals have been indispensable to human civilization.
Unique characteristics of Earth are also discussed. Earth's Interior Oil wells do more than just produce oil they serve as windows to Earth's interior.