Glossary

Fossil fuel: a fuel (as coal, oil, or natural gas) that is formed in the earth from plant or animal remains.

Oil: any of numerous unctuous combustible substances that are liquid or can be liquefied easily on warming.

Natural Gas: a combustible gas (a fluid, as air, that has neither independent shape nor volume but tends to expand indefinitely) or gaseous mixture for fuel or lighting.

Coal: a black or brownish black solid combustible substance formed by the partial decomposition of vegetable matter without free access of air and under the influence of moisture and often increased pressure and temperature that is widely used as a natural fuel.

Methane: a colorless odorless flammable gaseous hydrocarbon CH₄that is a product of decomposition of organic matter and of the carbonization of coal, is used as a fuel and as a starting material in chemical synthesis, and is the simplest of the alkanes.

Hydrocarbon: an organic compound (as acetylene or butane) containing only carbon and hydrogen and often occurring in petroleum, natural gas, coal, and bitumens.

Permafrost: a permanently frozen layer at variable depth below the surface in frigid regions of the earth.

Seismic: Pertaining to waves of elastic energy, such as that transmitted by compressional waves (P-waves) and shear (S-waves), in the frequency range of approximately 1 to 100 Hz. Seismic energy is studied by scientists to interpret the composition, fluid content, extent and geometry of rocks in the subsurface. "Seismic", used as an adjective, is preferable to "seismics," although "seismics" is used commonly as a noun.

Well logs: The measurement versus depth or time, or both, of one or more physical quantities in or around a well. The term comes from the word "log" used in the sense of a record or a note. Wireline logs are taken downhole, transmitted through a wireline to surface and recorded there. Measurements-while-drilling (MWD) and logging-while-drilling (LWD) logs are also taken downhole. They are either transmitted to surface by mud pulses, or else recorded downhole and retrieved later when the instrument is brought to surface. Mud logs that describe samples of drilled cuttings are taken and recorded on surface.

Continental slope: the usually steep slope from a continental shelf to the ocean floor.

Continental shelf: a shallow submarine plain of varying width forming a border to a continent and typically ending at the continental slope.

Gold: a malleable ductile yellow metallic element that occurs chiefly free or in a few minerals.

Dissociation: the process by which a chemical combination breaks up into simpler constituents; especially : one that results from the action of energy (as heat) on a gas or of a solvent on a dissolved substance.

Methanol: a light volatile flammable poisonous liquid alcohol CH₃OH used especially as a solvent, antifreeze, or denaturant for ethyl alcohol and in the synthesis of other chemicals.

Ethylene gycol: thick liquid diol (a compound containing two hydroxyl groups) C₂H₆O₂used especially as an antifreeze and in making polyester fibers.

Endothermic: characterized by or formed with absorption of heat.

Exothermic: characterized by or formed with evolution of heat.

Proton: an elementary particle that is identical with the nucleus of the hydrogen atom, that along with neutrons is a constituent of all other atomic nuclei, that carries a positive charge numerically equal to the charge of an electron, and that has a mass of 1.673 x 10^ê24 gram.

Magnetic moment: a vector quantity that is a measure of the torque exerted on a magnetic system (as a bar magnet or dipole) when placed in a magnetic field and that for a magnet is the product of the distance between its poles and the strength of either pole.

Radio frequency: any of the electromagnetic wave frequencies that lie in the range extending from below 3 kilohertz to about 300 gigahertz and that include the frequencies used for radio and television transmission.

References

1. Collett, Timothy S., Natural Gas Hydrates: Resource of the 21st Century?, U.S. Geological Survey on-line publication at http://energy.cr.usgs.gov/energy/OilGas/dis_cont.gas.html.
2. Collett, Timothy S., Lewis, Rick, and Uchida, Takashi, Oilfield Review, pg. 43-57, Summer 2000.
3. Clark, Brian, and Kleinberg, Robert, Physics in Oil Exploration, Physics Today, pg. 48-53, April 2002.
4. Kleinberg, Robert L., and Brewer, Peter G., Probing Gas Hydrate Deposits, American Scientist, p. 244-251, May-June 2001.
5. Gould, Todd A., How MRI Works, on-line article at http://www.howstuffworks.com/mri.htm.