Glossary

Analog - A mechanism in which data is represented by continuously variable physical quantities

Asthenosphere - Zone in the Earth's mantle that exhibits plastic properties. Located below the lithosphere at between 100 and 200 kilometers.

Backscattering - Portion of solar radiation directed back into space as a result of particle scattering in the atmosphere.

Basalt - A dark colored fine-grained igneous rock formed from mafic magma.

Bottom-boundary layer - The layer of water just above the sea floor that is particularly important for moving sediment.

Calibration - The process of converting units measured by an instrument (commonly volts) to a physical quantity relating to water or sediment characteristics. For example, an Ocean Bottom Seismometer (OBS) measures the backscatter of light and returns a signal is in volts. We can equate this signal to the suspended-sediment concentration (SSC) in the water column by taking water samples, determining their SSC and correlating that with output in volts.

Clinoform - A sedimentary deposit that has a sigmoidal (or S) shape. They can range in size from centimeters (like sand dunes) to kilometers (such as entire continental shelves), and can grow horizontally in response to sediment supply and physical limits on sediment accumulation.

Core - A device used to take a sample of the sediment on the seabed. There are many types of cores that are useful for different reason. See the Equipment section.

Continental Plate(s) - A rigid, independent segment of the lithosphere composed of mainly granite that floats on the viscous plastic asthenosphere and moves over the surface of the Earth. The Earth's continental plates are an average 125 kilometers thick and were formed more than 3 billion years ago. Also see oceanic plate.

Continental Crust - Granitic portion of the Earth's crust that makes up the continents. Thickness of the continental crust varies between 20 to 75 kilometers.

Continental Rise - Thick layers of sediment found between the continental slope and ocean floor.

Continental Shelf - Shallow, submerged margin of the continents that lies between the edge of the shoreline and the continental slope. This nearly level area of the continental crust has surface layers composed of sediment or sedimentary rock.

Continental Slope - Steeply sloping portion of the continental crust found between the continental shelf and continental rise.

CTD (Conductivity, Temperature, and Depth sensor) - A device deployed from the ship and lowered through the water column to determine salinity and temperature with water depth. These data are necessary for determining water density and sound speed. Additionally, a transmissometer, flourometer, and oxygen sensor are integrated with the Melville's system. See the Equipment section.

Crust - Earth's outer most layer of solid rock. Between 7-70 kilometers thick. Two types of crust exist: oceanic crust and continental crust.

Data - Information output by a sensing device or organ that includes both useful and irrelevant or redundant information and must be processed to be meaningful

Dip - One of the directional properties of a geologic structure such as a fold or a fault. Dip is the inclination angle of the formation as measured at right angles to strike.

Discharge - Water (or sediment where specified) leaving the mouth of a river.

ECU - East Carolina University

Fantail - A counter or after overhang of a ship shaped like a duck's bill, located at rear or stern of the ship

Fault - A fracture in rock caused by stress.

Feldspar - A group of common aluminum silicate minerals that contains potassium, sodium, or calcium.

Fetch - The distance of open water in one direction over which wind can blow.

Fold - Wavelike layers in rock strata that are a result of compression.

Geology - The field of knowledge that studies the origin, structure, chemical composition, and history of the Earth and other planets.

Granite - Medium to coarse-grained igneous rock that is rich in quartz and potassium feldspar. Derived from magma.

Granitic - A very hard natural igneous rock formation of visibly crystalline texture formed essentially of quartz and orthoclase or microcline and used especially for building and for monuments

Hertz - A unit of frequency equal to one cycle per second -- abbreviation Hz

Hydrophone - An instrument for listening to sound transmitted through water

Igneous Rock - Rocks formed by solidification of molten magma either beneath (intrusive igneous rock) or at (extrusive igneous rocks) the Earth's surface.

KHz (kilohertz) - 1000 hertz

Lithosphere - Is the solid inorganic portion of the Earth (composed of rocks, minerals, and elements). It can be regarded as the outer surface and interior of the solid Earth.

Magma - Molten rock originating from the Earth's interior.

Mantle - Layer of the Earth's interior composed of mostly solid rock that extends from the base of crust to a depth of about 2,900 kilometers.

Mid-oceanic ridge(s) - Chain of submarine mountains where oceanic crust is created from rising magma plumes and volcanic activity. Also associated with this feature is plate divergence that creates a rift zone.

Modeling - Mathematical representation of a system from which predictions or inferences can be made.

Mouth - The location where a river meets the sea.

Neap tide - Tide that occurs every 14 to 15 days and coincides with the first and last quarter of the moon. This tide has a small tidal range because the gravitational forces of the moon and sun are perpendicular to each other. Contrasts with spring tide.

NSF - National Science Foundation

Oceanic Plates (s) - Basaltic portion of the Earth's crust that makes up the ocean basins. Approximately 5 to 10 kilometers thick.

Oxygen Sensor - This instrument is used to determine the amount of dissolved oxygen in seawater. Calibration is necessary to provide accurate results.

PI - Principal Investigator

Plate(s) - Any of the large movable segments into which the earth's lithosphere is divided according to the theory of plate tectonics

Plate Tectonics - Theory suggesting that the Earth's surface is composed of a number of oceanic and continental plates. Driven by convection currents in the mantle, these plates have the ability to slowly move across the Earth's plastic asthenosphere. This theory is very important to geology and geomorphology because it helps to explain the occurrence and formation of mountains, folds, faults, volcanoes, earthquakes, ocean trenches, and the mid-oceanic ridges.

PNG - Papua New Guinea

PSU - Penn State University

Quantitative - Expressible in terms of quantity

S2S - Soure to Sink

SIO - Scripps Institution of Oceanography

Salinity - Concentration of dissolved salts found in a sample of water. Measured as the total amount of dissolved salts in parts per thousand. Seawater has an average salinity of about 34 parts per thousand.

Seabed - The floor of a sea or ocean (see seafloor).

Seafloor - The floor of a sea or ocean (see seabed).

Seaward - The direction or side away from land and toward the open sea

Sediment - Solid material that has been or is being eroded, transported, and deposited. Transport can be due to fluvial, marine, glacial or aeolian agents.

Seismic - Shaking displacement usually caused by an earthquake.

Spring Tide - Tide that occurs every 14 to 15 days and coincides with the new and full moon. This tide has a large tidal range because the gravitational forces of the moon and sun are complementary to each other. Contrasts with neap tide.

Squall Line - A band of thunderstorm development found ahead of a cold front.

Strata - A layers of sediment that are lain down sequentially with time, so the youngest layer is on top. They character of the layers (thin or thick, sandy or muddy) reflect the processes that operated to deposit the sediments.

Stratigraphy - Subdiscipline of geology that studies sequence, spacing, composition, and spatial distribution of sedimentary deposits and rocks.

Stern - The rear end of a ship.

Strike - One of the directional properties of a geologic structure such as a fold or a fault. Strike is the horizontal directional taken by an imaginary line drawn on the plane of the formation. Also see dip.

Subduction - Process of plate tectonics where one lithospheric plate is pushed below another into the asthenosphere.

Subduction zone(s) - Linear area where tectonic subduction takes place

Suspended-Sediment Concentration (SSC) - This is the amount of sediment suspended or floating in the water. This quantity is useful for understanding sediment transport. We determine SSC by collecting a water sample, filtering it onto a pre-weighed filter, and re-weighing it once its dry. The difference in weight is the mass of sediment in the volume of water filter. The SCC is this mass divided by the volume filter, so it has units of grams per liter (or g/L).

Tidal Range - The difference in vertical elevation between high and low tide.

Tide - Cyclical rise and fall of the surface of the oceans. Caused by the gravitational attraction of the sun and moon on the Earth.

Transmissometer - an instrument used to measure SSC. It sends a light beam across a distance of water (10 or 15 cm; 4 or 6 in), and determines the percentage of light that returns at the other side. This can be related to SSC with calibration.

VIMS - Virginia Institute of Marine Science