PACK-ICE
Pack ice is large block of ice on the surface of the ocean, usually in polar regions. They form when an ice field is broken up by strong waves and wind.
PALEOLITHIC
The period extending from 2 million to 10,000 B.P. Literally the Old Stone Age, the period when humans relied on a stone technology to sustain a scavenging/hunting/gathering adaptation (see).
PANGAEA
A huge "supercontinent" that encompassed most of the Earth's crust, 300 to 200 million years ago.
PANTALASSA
A prooto-ocean that covered two-thirds of the world except for the continent of Pangaea, 300 to 200 millions years ago.
PARAFFIN
White or colorless pertroleum-derived solid wax. It is often used in making candles and cosmetics.
PARASITISM
An antagonistic relationship in which one organism obtains its nutrition from another organism to the harm of the host.
PARTICULATE MATTER (PM)
Particles formed by incomplete combustion of fuel. Compression ignition (diesel) engines generate significantly higher PM emissions than spark ignited engines. The particles are composed of elemental carbon, heavy hydrocarbons (SOF), and hydrated sulfuric acid ("sulfate particulates").
PAYOUT
When the costs of drilling, producing and operating have been recouped (to make good a loss) from the sale of products on a well.
PCDDS AND PCDFS
Customary abbreviations for polychlorinated dibenzo-p-dioxins and dibenzofurans referring to the dioxins and furans (see).
