Appalachian Mountain landforms clearly demonstrate the relation of plate tectonics and structure to geomorphology. The folded rocks record the convergence of two continental plates in Pennsylvanian/Permian time. This page uses text, maps, and remotely sensed imagery to explain the relationship between plate tectonics, geologic structures, and the resulting landforms. It is part of an out-of-print ... Full description.

The mental picture of the Appalachian Mountains most of us have is that of long linear ridges and valleys that form a belt some 25 to 100 km wide through Pennsylvania/Virginia/West Virginia and the Carolinas. With relief of 300 to 1000 m or more, these ridges stand out as distinct mountains. This page describes the general geomorphology and geology of the Appalachian Mountains with the use of text ... Full description.

Much like El Nino, the North Atlantic Oscillation (NAO) varies in a rhythmic pattern from decade to decade. The NAO is the relationship between a high-pressure system over the Azores Islands and a low-pressure system over Iceland. This site uses text, photographs, and maps to explain what the NAO is and how it affects weather in Europe, the United States, and as far away as the Middle East. Full description.

This chapter on the formation of Karst topography discusses susceptible rock types, how dissolution occurs, and the general appearance of Karst landforms. Tables, maps, figures, and photographs of Karst landforms from around the world are included. It is part of 'Geomorphology from Space', an out-of-print publication of the National Aeronautics and Space Agency (NASA). Full description.

This web page enables the user to plot a map of current or historic climate data for the United States using datasets provided by the National Climatic Data Center. Users may choose among three types of variables (precipitation, temperature, and Palmer drought severity index), a variety of types of plots, and a range of dates from the present as far back as 1895. Links to other sites, datasets and ... Full description.

Users of this reference can access extensive information on each country, including maps, geographic data, environmental problems, and economic data. The factbook is searchable by country or by keyword. Full description.

This site provides information on the vast collection of deep-sea core samples that are stored in Lamont-Doherty Earth Observatory's (LDEO) facility in Palisades, New York. Materials presented here include a summary of how cores are taken, processed, and stored, some results of examinations of cores, a searchable database of the cores themselves, and a sample history database. Full description.

This site is provided by the Mineral Resources Program (MRP) of the U.S. Geologic Survey. It is an online geographic information system which covers Earth and the United States. Layers which can be turned on and off feature information on mineral resources, soils, sediments, geologic features, cultural features, land cover, elevation, gravity data, and magnetic data. Full description.

NASA's Visible Earth is a searchable directory of images, visualizations, and animations of the Earth. The images are also listed under the following categories: agriculture, atmosphere, biosphere, cryosphere, human dimensions, hydrosphere, land surface, oceans, radiance or imagery, solid earth, locations, and satellites. Accompanying each image are credits, data about the image, the satellite it ... Full description.

This site provides statistics and information on the worldwide supply of, demand for, and flow of minerals and materials essential to the U.S. economy and to national security. The database is searchable by commodity, country, state, or keyword. Links to a variety of related topics and publications are included. Full description.