Marine Geoscience Data System

MGDS Vocabulary: Data Type

ConductivityA measure of the ability of a medium to conduct electricity.
FluidFlowMeasurement of fluids (liquids and gases) in motion.
Gravity:Anomaly:FreeAirmeasurement of the difference between observed gravity and theoretical gravity that has been computed for latitude and corrected for elevation of the station above or below the geoid, by application of the normal rate of change of gravity for change of elevation, as in free air.
Chemistrydata concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions
VisualizationA rendering of volumes, surfaces, illumination sources, etc, sometimes with a temporal component.
Bathymetry:SwathBathymetry data derived from a multibeam sonar.
Seismic:PassiveMeasurements of ground motions generated by natural seismic sources, eg earthquakes, volcanic eruptions
SampleInfo:MicrobiologyAn inventory of microbiological samples physically acquired at a field site.
PhysicalProperties:RockA measure of the physical properties (e.g. permeability, porosity) of a rock sample.
Radiation:VisibleThe measurement of the electromagnetic spectrum that is visible to (can be detected by) the human eye.
Seismic:NavigationInformation about the position of the equipment during seismic data acquisition. This should include date, time, x and y.
WaveMeasurementMeasurements related to characteristics of waves such as wave height, period, direction.
Chemistry:Fluid:pHA measure of the acidity of a fluid.
Earthquake:Catalog:MicroseismicityAn inventory of earthquake positions and magnitudes.
Navigation:PrimaryPrimary ship navigation data product
Biology:Species:ListA list of organisms that were identified to species.
Biology:Species:AbundanceA quantification of species abundance in a particular sample.
Seismic:ReceiverFunctionReceiver function calculated from earthquake data
Chemistry:SedimentGeochemistry data derived from sediment samples.
SampleInfoMetadata about physical samples that were acquired.
LayerThickness:CrustCrustal thickness, may be in depth or twtt. May be determined from seismic, radar, gravity etc.
RugosityMeasurement of surface roughness (of a fluid)
Photograph:Video:TimeLapseA video assembled from time-lapse images
Bathymetry:SinglebeamBathymetry data derived from a single beam echosounder.
ElectromagneticMeasurement of physical field produced by electrically charged objects.
Radiation:InfraredThe measurement of electromagnetic radiation whose wavelength is longer than that of visible light (400-700 nm), but shorter than that of terahertz radiation (100 µm - 1 mm) and microwaves (~30,000 µm). Infrared radiation spans roughly three orders of magnitude (750 nm and 100 µm).
MagnetizationQuantity of magnetic moment per unit volume
ParticleFluxA measure of the rate at which settling particles pass through a parcel of air or water.
CurrentMeasurementA measure of fluid velocity based on the path of a fluid parcel over time or in-situ measurements of fluid flow.
ReflectorDepth:SeafloorSeismically-derived depth to the seafloor
Photograph:MosaicAn assemblage of images that have been rotated and scaled to create a composite view or image.
TurbidityAn indication of the cloudiness of a fluid associated with suspended particles. Can be measured with a variety of sensors including transmissometers, nephelometers, or secchi disks.
MagnetotelluricMeasurement of the electric currents under the Earth's surface induced by natural variations in the earth's magnetic field.
Seismic:Active:OBS:TravelTimePicksSeismic wave travel time picks derived from active-source shooting to OBS instruments
SampleInfo:BiologyAn inventory of biological samples physically acquired at a field site.
PressureThe force per unit area applied to the surface of an object.
Biology:GeneticSequenceA succession of letters representing the primary structure of a DNA molecule or strand.
TemperatureA measurement of how hot or cold a substance is.
Earthquake:CatalogAn inventory of earthquake positions and magnitudes.
TransmissivityThe fraction of incident light at a specified wavelength that passes through a sample
SampleInfo:RockAn inventory of rock samples physically acquired at a field site.
Seismic:WideAngle:OBHWide source-receiver offset data collected during active (also known as controlled) sorurce experiments using Ocean Bottom Hydrophones as the receivers.
Radar:ReflectionElectromagnetic waves scattered from any large change in the dielectric or diamagnetic constants.
Gravity:Anomaly:BouguerSimple (marine) Bouguer anomaly with no correction for modeled topography of a constant thickness, constant density crust.
Biology:LarvalFluxFlux of larvae measured at a particular location
BottomStressBottom stress refers to the shear stress experienced within the bottom boundary layer of a fluid and is a crucial component when understanding sediment transport.
AcousticScintillationThermometryA measurement of slight fluctuations in water temperature based on changes in the backscattered signal between successive sonar scans of an area of the seafloor.
Chemistry:Fluid:EhThe redox potential of a fluid, an indication of the tendency of chemical species to acquire electrons and thereby be reduced.
CrustalAgeMeasurement of the amount of time the crustal rock material has been isolated from the convecting mantle.
Chemistry:ParticulateChemistry data derived from particulate materials
Biology:Microbiology:CultureA pure microbiological culture is produced by promoting mircroogranisms to reproduce in predetermined culture media under controlled laboratory conditions.
FluorescenceMeasurement of luminescence that is mostly found as an optical phenomenon in cold bodies, in which the molecular absorption of a photon triggers the emission of a photon with a longer (less energetic) wavelength, though a shorter wavelength emission is sometimes observed from multiple photon absorption.
Biology:LarvalDistributionInformation about the larval population in an area. Could include spatial distribution information and/or species distribution.
Magnetic:FieldThe measurement of the Earth's total magnetic field.
Biology:SymbiontPhysiologyInformation about the function of the living systems of organisms that live within host organisms.
Mineralogy:SedimentCharacterization of the mineral composition of sediments.
RadiometricDatingData describing the age of materials, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates.
Backscatter:OpticalA measurement of the cloudiness of a medium derived from measuring the amount of light scattered by particles.
Observation:BirdField observations of birds noted during science operations.
SidescanBackscatter intensity data acquired with a sidescan sonar or similar data acquired with a multibeam sonar.
DocumentationUse this data type for documentation that can be specifically tied to a data set, then map the two data sets. This data type will capture much of what we used to put in the entry_url table.
GeodesyMeasurement of crustal deformation.
PhysicalProperties:Sediment:AncillaryAncillary data such as calibration files.
NavigationInformation about the position of a platform or device. Minimally this includes x and y, but often date and time are also included.
BathymetrySeafloor depth data.
Chemistry:RockGeochemistry data derived from rock samples.
Bathymetry:ReferenceSurfaceA bathymetry grid produced over a flat area of seafloor that is used to test the performance of a multibeam sonar system.
Biology:ElectrobiologyData describing the electrical phenomena of living organisms.
SalinityA measure of the dissolved salt content of a body of water. Often computed from Conductivity.
SampleInfo:SedimentAn inventory of sediment samples physically acquired at a field site.
Backscatter:AcousticAcoustic backscatter intensity, the intensity of sound that is scattered back toward an acoustic transducer.
ModelParametersGeneral data type for any files used to define the parameters of a model. Includes calibration, configuration, geometry, weighting information and so on.
Seismic:WideAngleWide source-receiver offset seismic data
Seismic:Passive:ComplianceMeasurements of the vertical displacement of the seafloor related to low frequency ocean waves (infragravity waves).
EnvironmentalDebrisData quantifying anthropogenic environmental debris on the environment.
Interpretation:GeologicAn interpretation of the characteristics of some component of the earth based on scientific assessment of one or more data types.
Radiation:GammaMeasurement of radiation of photons with a frequency of greater than 1019 Hz.
Visualization:FledermausFledermaus formatted visualization files (*.sd, *.scene) of surfaces and/or volumes that can be viewed with free software from IVS3D (
Bathymetry:BPIBathymetric Positioning Index (BPI) derived from ArcGIS Benthic Terrain Modeler(BTM). The BPI is a measure which allows calculating where a certain location with a defined elevation is relative to the overall landscape.
Sediment:DescriptionCan include grain size distribution data derived from sediment samples, classfication of sediments (sand, mud clay) and/or descriptions of environmental parameters relevant to ecological processes.
Photograph:Video:FrameGrabStill images frame grabbed from video stream.
TurbulenceA measure of the chaotic, stochastic property changes of a fluid flow.
Temperature:DiffusivityA measure of thermal diffusivity
Photograph:VideoStreaming images generated on film or digital media.
Bathymetry:PhaseBathymetry data derived from the phase difference measured between two closely spaced receiving arrays.
Chemistry:Fluid:Electrochemistrydata concerning chemical reactions which take place in a solution at the interface of an electron conductor (a metal or a semiconductor) and an ionic conductor (the electrolyte), and which involve electron transfer between the electrode and the electrolyte or species in solution.
X-radiographType of data used, for example, in analysis of sediment core stratigraphy. Produced by a specialised x-ray machine.
Seismic:Passive:OBHData from Ocean Bottom Hydrophones deployed to detect water column motions generated by natural seismic sources, eg earthquakes, volcanic eruptions.
Magnetic:AnomalyMeasurement of the local variation in the Earth's magnetic field
Flux:Air-SeaFluxes of momentum, sensible heat, and carbon dioxide over the ocean.
HeatflowMeasurement of the transition of thermal energy from a hotter object to a cooler object
Biology:Species:DistributionInformation about the observed spatial distribution of different species.
Seismic:Reflection:SCSData collected using the principles of seismology to estimate the properties of the Earth's subsurface from reflected seismic waves generated by a single sound source.
Geodesy:VelocityGPS velocity derived from geodetic (GPS) measurements.
HydroacousticWaveform data collected by sound-channel moored hydrophones typically used for monitoring undersea seismicity or marine mammal activity.
ResistivityA measure of how strongly a material opposes the flow of electric current.
ReflectorDepth:MohoSeismically-derived depth to the Moho
PhysicalProperties:Rock:AncillaryAncillary data, such as a calibration file, related to physical properties of rock.
PhotographA still image acquired with a digital or film camera.
Magnetic:Anomaly:IGRFMagnetic Anomaly with the International Geomagnetic Reference Field (IGRF), a standard mathematical description of the Earth's main magnetic field, removed
Velocity:DopplerA continuous-wave trajectory-measurement using the Doppler effect.
SampleInfo:FluidAn inventory of fluid samples physically acquired at a field site.
Seismic:Passive:OBSData from Ocean Bottom Seismometers deployed to detect ground motions generated by natural seismic sources, eg earthquakes, volcanic eruptions.
TravelTime:AcousticTravel time for acoustic waves between, say, a modem and a logger such as those used in seafloor geodesy studies
Visualization:GoogleEarthAn assembly of information (e.g. images, lines, placemarks) written in KML/KMZ format for display in Google Earth.
MeteorologicalMeasurement of data related to atmosphere that focuses on weather processes and forecasting.
IceConcentrationArea of a surface covered in ice. Often an image or diagram that shows sea ice over bodies of water.
Seismic:Velocity:ModelSeismic velocity data obtained from a model. Model inputs generally include information on layer thickness, source-receiver geometry, weighting factor, etc.
Biology:MicrobiologyData about microorganisms, including eukaryotes (fungi and protists), and prokaryotes (bacteria and archaea).
Pseudorange:GNSSThe apparent distance between a satellite and a navigation satellite receiver.
Conductivity:ThermalA measure of the ability of a medium to conduct heat.
Seismic:WideAngle:OBSWide source-receiver offset data collected during active (also known as controlled) source experiments using Ocean Bottom Seismometers as the receivers.
Bathymetry:PaleobathymetryA reconstruction of a past bathymetric surface derived from sub-seafloor observations.
Earthquake:Catalog:Microseismicity:FocalMechanismsEarthquake focal mechanism solutions
Velocity:SoundThe speed of sound.
Photograph:WebGalleryA gallery of photographs that can be viewed and explored through an internet browser.
Seismic:WideAngle:ESPsExpanding Spread Profile seismic data collected during active (also known as controlled) source experiments involving two ships.
PhysicalProperties:SedimentA measure of the physical properties (eg density, porosity, magnetic susceptibility) of sediments, usually from a sediment core logger/scanner device.
DensityThe density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume.
LayerThickness:SeismicLayer2ASeismic 2A layer thickness, in meters or two way travel time.
Seismic:Reflection:MCSData collected using the principles of seismology to estimate the properties of the Earth's subsurface from reflected seismic waves generated by multiple sound sources.
ThermalGradientTemperature as a function of depth
OxygenA measurement of oxygen in a substance. May be dissolved oxygen, % oxygen saturation, etc.
Chemistry:Fluiddata concerned with the composition, structure, and properties of fluids, as well as the changes it undergoes during chemical reactions
Gravity:Predicted:PlateCoolingPredicted gravity contribution of plate cooling.
RadiationThe measurement of energy emitted by a body.
Seismic:Active:SubbottomData on reflectivity of sedimentary or rock layers beneath the seafloor collected with CHIRP and similar systems typically operating in the few Hz up to about 50 Hz range
Biology:Microbiology:DiversityA measure of the variety of microorganisms at the genetic, species and ecosystem levels.