Earth Sciences
The Earth sciences are the fields of study concerned with the solid Earth, its waters, and the air that envelops it. Included are the geologic, hydrologic, and atmospheric sciences.
Earth Sciences Encyclopedia Articles
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North America
North America, third largest of the world’s continents, lying for the most part between the Arctic Circle and the Tropic of Cancer. It extends for more than 5,000 miles (8,000 km) to within 500 miles (800...
plate tectonics
Plate tectonics, theory dealing with the dynamics of Earth’s outer shell—the lithosphere—that revolutionized Earth sciences by providing a uniform context for understanding mountain-building processes,...
geography
Geography, the study of the diverse environments, places, and spaces of Earth’s surface and their interactions. It seeks to answer the questions of why things are as they are, where they are. The modern...
metamorphic rock
Metamorphic rock, any of a class of rocks that result from the alteration of preexisting rocks in response to changing environmental conditions, such as variations in temperature, pressure, and mechanical...
mineral
Mineral, naturally occurring homogeneous solid with a definite chemical composition and a highly ordered atomic arrangement; it is usually formed by inorganic processes. There are several thousand known...
Africa
Africa, the second largest continent (after Asia), covering about one-fifth of the total land surface of Earth. The continent is bounded on the west by the Atlantic Ocean, on the north by the Mediterranean...
Europe
Europe, second smallest of the world’s continents, composed of the westward-projecting peninsulas of Eurasia (the great landmass that it shares with Asia) and occupying nearly one-fifteenth of the world’s...
Antarctica
Antarctica, the world’s southernmost and fifth largest continent. Its landmass is almost wholly covered by a vast ice sheet. Often described as a continent of superlatives, Antarctica is not only the world’s...
South America
South America, fourth largest of the world’s continents. It is the southern portion of the landmass generally referred to as the New World, the Western Hemisphere, or simply the Americas. The continent...
sedimentary rock
Sedimentary rock, rock formed at or near Earth’s surface by the accumulation and lithification of sediment (detrital rock) or by the precipitation from solution at normal surface temperatures (chemical...
dating
Dating, in geology, determining a chronology or calendar of events in the history of Earth, using to a large degree the evidence of organic evolution in the sedimentary rocks accumulated through geologic...
hydrosphere
Hydrosphere, discontinuous layer of water at or near Earth’s surface. It includes all liquid and frozen surface waters, groundwater held in soil and rock, and atmospheric water vapour. Water is the most...
Earth sciences
Earth sciences, the fields of study concerned with the solid Earth, its waters, and the air that envelops it. Included are the geologic, hydrologic, and atmospheric sciences. The broad aim of the Earth...
global warming
Global warming, the phenomenon of increasing average air temperatures near the surface of Earth over the past one to two centuries. Climate scientists have since the mid-20th century gathered detailed...
Asia
Asia, the world’s largest and most diverse continent. It occupies the eastern four-fifths of the giant Eurasian landmass. Asia is more a geographic term than a homogeneous continent, and the use of the...
climate
Climate, conditions of the atmosphere at a particular location over a long period of time; it is the long-term summation of the atmospheric elements (and their variations) that, over short time periods,...
lake
Lake, any relatively large body of slowly moving or standing water that occupies an inland basin of appreciable size. Definitions that precisely distinguish lakes, ponds, swamps, and even rivers and other...
geology
Geology, the fields of study concerned with the solid Earth. Included are sciences such as mineralogy, geodesy, and stratigraphy. An introduction to the geochemical and geophysical sciences logically begins...
metallurgy
Metallurgy, art and science of extracting metals from their ores and modifying the metals for use. Metallurgy customarily refers to commercial as opposed to laboratory methods. It also concerns the chemical,...
geomagnetic field
Geomagnetic field, magnetic field associated with Earth. It is primarily dipolar (i.e., it has two poles, the geomagnetic North and South poles) on Earth’s surface. Away from the surface the dipole becomes...
