Geology or Related Geological Terms +

(a glossary, or dictionary, of terms used in geology; the science of the earth including its origin, composition, structure, and history)

diastrophic forces
A reference to the forces that act parallel to the earth's surface and which produce the folded and faulted geological structures seen in mountain areas.

In geology, folds (curvatures in layered rocks) are generally associated with sedimentary rocks, those that usually have horizontal layers.

Large-scale deformation of the earth's crust by natural processes, which leads to the formation of continents and ocean basins, mountain systems and rift valleys, and other features by mechanisms such as lithospheric plate movement (plate tectonics), volcanic loading, or folding.

The study of diastrophism, or tectonic processes, is the central unifying principle in modern geology and geophysics.

earthquake, seism
1. A violent shaking of the earth's crust that may cause destruction to buildings and results from the sudden release of tectonic stress along a fault line or from volcanic activity.
2. Any event that causes an upheaval in society, politics, or someone's life.

Predicting Earthquakes

Almost all earthquakes are insignificant. A small segment of a fault, far underground, jerks a little, but the rumble is imperceptible at the surface and not even noticed.

With a few quakes, the fault continues to break and the ground jumps significantly resulting in the earth shaking in cataclysms.

A gap in geological knowledge apparently makes earthquake predictions a frustrating and unreliable effort to calculate the true risk that human constructions like a water reservoir or a geothermal power plant could inadvertently set off a deadly quake.

Scientists know that some human activities from oil extraction to power plants can trigger an earthquake.

Geologists do not know how the pieces of the earth's crust that usually squeeze together tightly with high friction slip past each other smoothly during a large earthquake, as if sandpaper suddenly changed into Teflon."

—Compiled from excerpts in
"The race to predict earthquakes" by Kenneth Chang;
International Herald Tribune; April 17, 2009; page 2.
fault (s), faults (pl)
A fracture in the earth's crust where adjacent blocks of stone formations have shifted relative to one another.

Faults can extend for hundreds of miles. Perhaps the most famous is the "San Andreas Fault", which is 600 miles long, from the Mohave Desert to the Pacific Coast, north of San Francisco. It was the sudden shift of this fault that caused the San Francisco earthquake in 1906.

fluorite mineral
A well known mineral prized for its glassy luster and rich variety of colors.

Used as a flux in iron smelting, a rare gemstone, a source of fluorine, as special optical lenses, and a popular mineral specimen.

fold (s), folds (pl)
Curvatures in layers of rocks, generally found in rock formations that were originally horizontal and produced by stresses in the crust of the earth.

The angle of deformation of folds ranges from very small to extremely contorted; their size ranges from a few inches to many miles.

When folded rocks erode, the result is a series of parallel ridges and valleys; such as, those that can be observed in the Appalachian Mountains, the mountain range in the eastern United States extending from Quebec, Canada, to the Gulf of Mexico.

Friedrich Mohs
A German mineralogist and geologist (January 29, 1773-September 29, 1839) who originated the "Mohs scale of hardness".
geoengineering, planetary engineering
1. The artificial manipulation of the environments of the earth; especially, as a means of counteracting global warming.
2. Proposals to deliberately manipulate the earth's climate to counteract the effects of global warming from greenhouse gas emissions.

So far, no large-scale geoengineering projects have been undertaken, nor has a consensus been reached that geoengineering is desirable.

President Obama’s science adviser, Dr. John Holdren, after giving his first round of interviews (April 10, 2009) immediately caused a ruckus by airing his thoughts on geoengineering; the large-scale tinkering with the earth’s climate to chill runaway global warming climate changes that could potentially slow or reverse global warming.

Holdren emphasized that even if he personally thinks it prudent to start evaluating geoengineering options, he still believes that the most pressing concern should be curbing greenhouse gas emissions to prevent global warming from reaching catastrophic proportions.

—Compiled from information found in the article,
"Obama’s Science Adviser Kicks Up a Fuss Over Geoengineering"
by Eliza Strickland; Discover, Science, Technology, and the Future
Web Site, April 10, 2009.
The science of the earth, its origin, composition, structure, and history.

It is divided into such branches as: mineralogy (the minerals of the earth), petrology (rocks), stratigraphy (the deposition of successive beds of sedimentary rocks), paleontology (fossils), and tectonics (the deformation and movement of the earth's crust).

Those who explain topographic features in terms of three major geological processes: weathering; diastrophism (process or combination of processes by which the earth's crust is deformed); and igneous activity, or volcanism.
The study of the surface features of the earth, focusing largely on their origins and development.

Geomorphology is closely related to physiography, which covers much of the same subject matter, but includes oceanography and climatology, the study of the earth's climate and oceans.

Energy which is generated from heat from inside the earth.

This form of energy is both clean, sustainable, and renewable and the technology has caught on in countries with substantial geothermal activity; such as Iceland, where it accounted for 54 percent of primary energy use.

Resources of geothermal energy range from the shallow depths of hot water and hot rock found a few miles beneath the earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma.

In the United States, the best sources for geothermal power are in the west, where there are many underground lakes of heated water; however, large-scale access would require drilling.

A major goal is to find a way to harness energy directly from magma (molten rock material), which has great potential because of its high temperature.

geothermal future
Most people think the word "geothermal" means hot springs and geysers; such as, parts of Iceland or Yellowstone National Park where water is heated by the presence of magma near the surface of the earth.

The earth’s heat lies below the surface everywhere, and it is believed that it offers an untapped energy reserve of enormous potential with a very short list of drawbacks.

Some of the negative aspects of geothermal development is that it will mean more competition for scarce water, more holes in the ground, and more roads to service those holes.

geothermal heat pump
A heat pump in which the refrigerant exchanges heat (in a heat exchanger) with a fluid circulating through an earth connection medium (ground or ground water).

The fluid is contained in a variety of loop (pipe) configurations depending on the temperature of the ground and the ground area available.

Loops may be installed horizontally or vertically in the ground or submersed in a body of water.

geothermal resources
Geothermal resources range from shallow ground to hot water and rock several miles below the earth's surface, and even farther down to the extremely hot molten rock called magma.

Mile-or-more-deep wells can be drilled into underground reservoirs to tap steam and very hot water that can be brought to the surface for use in a variety of applications. In the United States, most geothermal reservoirs are located in the western states, Alaska, and Hawaii.

Index of additional Scientific and Technological Topics.