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salinity

The saltiness or dissolved salt content of a body of water. On average, seawater in the world's oceans has a salinity of about 3.5%, or 35 parts per thousand (ppt). Fresh water (found in lakes and rivers) has less than 0.5 ppt dissolved salts.

SCAT

Shoreline Cleanup Assessment Team. During oil spill response, Shoreline Cleanup Assessment Teams (SCAT) systematically survey and document the affected area to provide a rapid and accurate geographic picture of shoreline oiling conditions. The information is used to develop real-time decisions regarding shoreline treatment and cleanup operations.

Scientific Support Coordinator (SSC)

The point of contact for the Scientific Support Team from NOAA OR&R's Emergency Response Division (ERD). In accordance with the National Contingency Plan, the SSC provides the Federal On-Scene Coordinator scientific advice regarding the best course of action during a spill response. Using the resources of a Scientific Support Team, the SSC provides expertise on chemical hazards, field observations, trajectory analysis, resources at risk, environmental tradeoffs of countermeasures and cleanup methods, and information management. Additionally, the SSC provides data on weather, tides, currents, and other applicable environmental conditions. SSCs are geographically located in Coast Guard districts throughout the U.S.

Scientific Support Team (SST)

NOAA's multi-disciplinary team of scientists, based in Seattle and led by nine regionally-based Scientific Support Coordinators (SSCs). The team provides expertise in environmental chemistry, aerial observations, pollutant transport modeling, resources at risk, environmental tradeoffs of countermeasures and cleanup, and information management. The SST also provides data on weather, tides, currents, and other applicable environmental conditions.

Sector

A shore-based operational command responsible for the execution of all Coast Guard missions within its area of responsibility (e.g., search and rescue, ensuring navigation safety, pollution response and investigation, etc.).

sediment

A general term used to describe or refer to: material in suspension in air or water; the total dissolved and suspended material transported by a stream or river; the unconsolidated sand and gravel deposits of river valleys and coastlines; and materials deposited on the floor of lakes and oceans.

sedimentation

Due to weathering the density of some heavy spilled oils may increase and become higher than that of the sea water, so that they sink. Oil may also be absorbed by heavy mineral particles (sand, silt, etc.) and thus sink.

sensitivity maps

See ESI maps.

sensitizer

Substance that can cause an allergic reaction in some people; the reaction can be severe, and breathing can be obstructed.

sheen

A very thin layer of oil (less than 0.0001 inches or 0.003 millimeters in thickness) floating on the water surface. Sheen is the most commonly observed form of oil during the later stages of a spill. Depending on thickness, sheens range in color from dull brown for the thickest sheens to rainbows, grays, silvers, and near-transparency in the case of the thinnest sheens.

shock wave

A pressure wave generated by an explosion.

shoreline assessment

A segment-by-segment survey of oiled shoreline to collect information about the shoreline habitats, type and degree of shoreline contamination, and spill-specific physical processes. The field data are collected in order to provide specific cleanup recommendations to maximize the recovery of oiled habitats and resources, while minimizing the risk of injury from cleanup efforts.

shoreline cleanup

The collection of oil stranded onshore or floating in shallow intertidal areas. Cleanup methods can include barriers and berms, manual or mechanical oil removal, the use of sorbents or vacuums, sediment reworking/tilling, vegetation cutting/removal, etc. Natural recovery is sometimes used, in which no attempt is made to remove stranded oil, when there is no effective method for cleanup or to minimize impact to the environment. The oil is left to degrade naturally. Overall, a cleanup strategy that minimizes the impact to all sensitive aspects of the environment and minimizes the amount of oily wastes is the most optimal.

shoreline sensitivity

The susceptibility of environment to any disturbance that might decrease its stability or result in short or long-term adverse impacts. Shorelines that are most susceptible to damage from stranded oil are usually equally sensitive to cleanup activities that may alter physical habitat or disturb associated flora and fauna. The most sensitive shoreline environments are marshes and lagoons, while exposed coastline, subject to heavy wave action, is generally least affected by oil and/or cleanup activities.

Side-Looking Airborne Radar (SLAR)

This aircraft-mounted device emits radiation and looks at the return signal. It looks for "damped areas," does not work well if winds are calm (there are no capillary waves to suppress) or if winds are too strong (greater than 15-20 knots). It needs ground-truthing; false positives include kelp beds, lee of bluffs, etc. However, it can cover a large area in a short amount of time and can be used at night or through clouds.

SITREP

Situation Report. A written account generated by the U.S. Coast Guard, and usually issued on a daily basis, detailing the status of a spill and its response.

skimmer

A floating device used to remove oil from the water’s surface by any of a variety of mechanical methods (e.g., weir, oleophilic belt or drum). Skimmers may be stationary, towed, or self-propelled. Skimmers come in a wide range of shapes and sizes, designed for different sea conditions and types of oil. Skimmers are often used in conjunction with booms to increase collection efficiency, and a reservoir or bladder to store collected oil.

skin absorption

Chemical exposure through the skin. Because the skin does not act as a reliable barrier to hazardous chemicals, it can be a route of acute poisoning. Compounds such as dimethyl sulfoxide are known to be directly absorbed into the bloodstream through the skin.

slick

The common term used to describe a film of oil (usually less than 2 microns thick) on the water surface. Oil spilled on the water absorbs energy and dampens out surface waves, making the oil appear smoother--or slicker--than the surrounding water.

sludge

A thick or viscous mixture of solids in aqueous solution, such as sewage sludge.

SMART

Special Monitoring of Applied Response Technologies. SMART is a cooperatively designed monitoring program for dispersant and in situ burning operations.

snares

See pom-poms.

solubility

A measure of a chemical's ability to dissolve in water. If a chemical is highly soluble, it will dissolve easily into water.

solute/solvent

A solute is a gas, liquid, or solid substance that is uniformly dispersed in a liquid solvent substance, forming a solution. The solvent molecules act to break the solute molecules' attraction for one another, and also the solvent's natural structure. For instance, water is a highly-structured substance, in the absence of any solutes. See also solution.

solution

Mixtures of chemicals in which the components are interspersed uniformly at the molecular level. See also solute/solvent.

sorbent

Any material that absorbs oil or to which oil adheres. A sorbent should be oleophilic and hydrophobic (i.e., it should absorb petroleum or products from 0 to 25 times its weight, and repel water). Sorbents are available in many forms: sheets, booms, sweeps, blankets, and loose material. Sorbents may be made of polymer beads, synthetic hydrocarbon polymers, cellulose, plastic fiber, and even straw.

sorbent barrier

A barrier which is constructed of or includes sorbent materials to simultaneously recover spilled oil during the containment process. Sorbent booms and barriers are used only when the oil slick is relatively thin since their recovery efficiency rapidly decreases once the sorbent is saturated with oil.

SOSC

See State On-Scene Coordinator.

spawn

To release and fertilize eggs, as done by a number of aquatic species (fish, oysters, etc.) to reproduce.

specific gravity

Density expressed as the ratio of the weight of a substance, such as oil, to the weight of an equal volume of another standard substance. In the case of liquids and solids, the standard is water. In the case of natural gas or other gas materials, the standard is air. Buoyancy is intimately related to specific gravity; if a substance has a specific gravity less than that of a fluid, it will float on that fluid. The specific gravity of most crude oils and refined petroleum products is less than 1.0 and therefore, these substances generally float on water. A substance with a specific gravity greater than 1.0 will sink rather than float in water. See also density.

spill response

All actions taken in carrying out responsibilities to spills of oil and hazardous materials, e.g., receiving and making notifications; information gathering and technical advisory phone calls; preparation for and travel to and from spill sites; direction of cleanup activities; damage assessments; report writing, enforcement investigations and actions; cost recovery; and program development.

spill trajectory

See trajectory.

spreading

When crude oil or refined petroleum product is poured onto clear water surfaces, it tends to spread out to a thin film. Most crude oils spread to a thickness of some tenths of millimeter after one hour, and to only a few microns after two or three hours. In reality, oil, when spilled onto the sea, will form windrows (elongated thick patches of oil separated by areas of clear water or water covered by a thin film of oil). The spreading rate will be affected by many factors, such as oil thickness near the source of the spill; type of oil (boiling range, wax content, viscosity, presence of natural surface active compounds); sea state; weather conditions; unimpeded surface area water availability; contamination in the vicinity of the spill, by floating debris; the limitation of free water surface due to seaweed or the presence of natural or man-made structures (rock, jetties, etc.); and the modification of the pollutant composition (emulsion build-up).

SSC

See Scientific Support Coordinator.

staging area

The location where incident personnel and equipment are assigned awaiting tactical assignment.

State On-Scene Coordinator (SOSC)

Spill responder responsible for spills of oil and hazardous substances occurring in state.

streamer

A narrow line of oil, mousse, or sheen on the water surface, surrounded on both sides by clean water. Streamers result from the combined effects of wind, currents, and/or natural convergence zones. Often, heavier concentrations of mousse or sheen will be present in the center of a streamer, with progressively lighter sheen along the edges. Streamers are also often called "fingers" or "ribbons."

strike team

A set number of resources of the same kind and type that can be assembled for a specific mission. Also, one of the U.S. Coast Guard's three National Strike Force teams that respond to oil and hazardous chemical incidents.

sublethal effect

A toxic effect that does not directly cause death, but does affect behavior, biochemical or physiological functions, or tissue integrity.

sublime

A frozen substance sublimes when it passes directly into the gas phase without first becoming liquid. Substances that sublime include solid carbon dioxide, sulfur, camphor, and naphthalene.

Superfund

The Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended by the Superfund Amendments and Reauthorization Act (SARA) in 1986, often referred to as Superfund. This federal statute establishes liability for site cleanup, prescribes a procedure for identifying and ranking contaminated sites, provides a funding mechanism for site cleanups, reduces uncontrolled releases of hazardous substances, establishes cleanup procedures that provide protection for humans and the environment, and restores injured natural resources through provisions administered by the natural resource trustees.

surface tension

The force of attraction between the surface molecules of liquid. Surface tension affects the rate at which spilled oil will spread over a land or water surface, or into the ground. Oils with low specific gravities are often characterized by low surface tensions and therefore faster spreading rates.

surfactant

A substance that reduces surface tension of liquids. Nearly synonymous with detergent (which reduces the surface tension of water), wetting agent, and emulsifier.

suspension

A uniformly-dispersed mixture of fine particles in a liquid.

swell

Long and relatively uniform wind-generated ocean waves that have traveled out of their generating area.