Images of an actual landslide illustrate the phenomenon. Sedimentary Rocks: The Key to Past Environments This program returns to the Grand Canyon: its exposed layers of sedimentary rock allow scientists to peer into the geologic past. Metamorphic Rocks The weight of a mountain creates enough pressure to recrystallize rock, thus creating metamorphic rocks.
The movement of sediment and its deposition are covered, and the processes of lithification, compaction, and cementation that produce sedimentary rocks are explained. This program outlines the recrystallization process and the types of rock it can create from claystone and slate to schist and garnet-bearing gneiss.
The program covers convergent boundaries, subduction, hotspots, and the debate over what drives plate motion. Mountain Building This program erodes the myth of the mountain as a solid, permanent structure.Animations are used to illustrate the process of orogeny (mountain building) through accretion and erosion, as well as the role of plate tectonics, the rock cycle, and how different types of rock are formed in the course of mountain building. Earth's Structures A visit to the Grand Canyon lays the foundation for this exploration of rock layers and deformation.The program covers sedimentation, major structures, the methods used to examine them, and how petroleum may be trapped inside them.It also looks at tectonic force and the different types of stress involved in the formation of geologic structures. Earthquakes Showing actual footage of earthquakes and their aftermath, this program discusses the forces that fuel these massive events.The evolution of rivers is covered, along with efforts to prevent harmful consequences to humans. Groundwater Approximately three-quarters of Earth's surface is covered by water. Topics of this program include aquifers, rock porosity and permeability, artesian wells, the water table, cave formation, sinkholes, and how groundwater may become contaminated. Wind, Dust and Deserts Land in arid climates is shaped in particular ways.
This program shows how deserts are defined by infrequent precipitation and how desertification relates to proximity to the equator, proximity to mountains, and ultimately plate tectonics.The program provides images of glaciers and glacial landforms such as moraines, and discusses how study of glaciers may help us understand ice ages and the greenhouse effect. Waves, Beaches and Coasts This program shows the dynamic interaction of two geologic agents: rocky landmasses and the energy of the ocean.Aspects of waves their types, parts, movement, and impact on the shore are illustrated.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.The timeline of major geologic events is superimposed onto the year for a condensed view of Earth's evolution.