IncidentNews Home  >>  Glossary  >>  D

D

About A B C D E F G H I J K L M N O P R S T U V W References

DAC

See Damage Assessment Center.

Damage Assessment Center (DAC)

One of three offices within NOAA's Damage Assessment, Remediation, and Restoration Program (DARRP). DAC is responsible for assessing the impact to NOAA trust resources from releases of oil and hazardous materials to achieve the goal of restoration. DAC staff determines what resources have been injured and lost to the public, and identifies resources that should be restored.

Damage Assessment, Remediation, and Restoration Program (DARRP)

A NOAA program that collaborates with other agencies, industry, and citizens to protect and restore coastal and marine resources threatened or injured by oil spills, releases of hazardous substances, and vessel groundings (www.darrp.noaa.gov).

DARRP

See Damage Assessment, Remediation, and Restoration Program.

decomposition

The breakdown of a material or substance by heat, chemical reaction, electrolysis, decay, or other processes.

deflagration

Rapid, sharp combustion with sudden evolution of flame. The flame front travels relatively slowly (subsonic speeds), as compared to a supersonic detonation. Contrast with detonation.

demobilization

The deactivation of equipment, personnel, and other resources involved in response operations.

density

The ratio of the mass (weight) of a substance to the volume it occupies. For example, if 1 cubic foot of a substance weighs 10 pounds, its density is 10 pounds per cubic foot. The units used to express density can vary; however, it is often expressed as grams per cubic centimeter (e.g., the density of water is 1.0 g/cm3).

detergent

A natural or synthetic agent that suspends emulsified oils, greases, and fats in solution and, by doing this, acts as a cleaning agent. Examples of detergents include soaps and various alcohols, sulfonated organics like dodecylbenzene, and various alkylates.

detonation

An explosion where the flame front travels at supersonic speeds as a shock wave. Contrast with deflagration.

DHS

Department of Homeland Security (www.dhs.gov). The U.S. federal agency whose primary mission is to help prevent, protect against, and respond to acts of terrorism on U.S. soil.

dispersant

A chemical that causes oil to break into small droplets by reducing the surface tension between the water and oil. Once formed, these droplets can be dispersed and degraded in the environment at a faster rate than would occur as a surface slick. Use of dispersants is subject to federal and state approval.

dispersion

(1) The movement of spilled oil from the water surface down into the upper layers of the water column, caused either by natural wave action or by the application of chemical dispersants made for this purpose.
(2) The movement of molecules or finely divided particles through a gaseous or liquid medium (e.g., the spreading of a chemical cloud in the atmosphere).

dissolution

The process of oil dissolving into the water column. The extent of dissolution depends on the oil's solubility in water.

DOD

Department of Defense (www.defenselink.mil). The U.S. department that provides military forces needed to deter war and to protect the security of the country.

DOI

Department of the Interior (www.doi.gov). The U.S. department that protects and provides access to the country's natural and cultural heritage, and honors its trust responsibilities to Indian Tribes and its commitments to island communities.

DOT

Department of Transportation (www.dot.gov). The U.S. department that oversees federal highway, air, railroad, maritime, and other transportation administration functions.

DOT label

Required Department of Transportation (DOT) hazard warning label for a chemical (e.g., "Flammable Liquid," "Corrosive").

dredge

A device used to remove sediment from the bottom of a water body.

drift card

A thin, postcard-sized piece of painted wood released into the sea for use in studying currents. A drift card usually identifies the date and place of release, and requests that the finder return it with date and place of recovery.