Alphabetical listing of categories: S

aviation safety (1) human environmental safety (9) safety issues (human) -> human environmental safety (9) ocean salinity (2) salinity (3) salt-water intrusion -> saltwater intrusion (1) salt deposit areas -> mineral deposit areas (5) salt evaporation ponds -> lakes (25) intermittent salt lakes -> lakes (25) salt lakes -> lakes (25) salt marshes -> wetlands (26) salt mines -> mine sites (7) intermittent salt ponds -> lakes (25) salt ponds -> lakes (25) saltwater intrusion (1) core sampling -> drilling and coring (16) field sampling (101) ice core sampling (1) -> snow and ice cover WITH drilling and coring plot sampling (2) transect sampling (1) water sampling (40) sanctuaries (wildlife) -> reserves (2) sandbars -> bars (physiographic) (1) sand deposits (2) sandy areas -> beaches (2) sandy deserts -> deserts (9) sanitary landfills -> disposal sites (2) SAR interferometry -> IFSAR (4) satellite images (31) -> remote sensing WITH image collections satellite imaging -> remote sensing (79) satellite photography -> visible light imaging (1) satellite stations -> data collection facilities (1) savannahs -> grasslands (10) savannas -> grasslands (10) scanning electron microscopy (1) scenic areas -> parks (7) careers in science -> scientific careers (8) computer science (1) atmospheric sciences (31) biological sciences -> life sciences (361) earth sciences (865) engineering sciences (13) geographic information sciences -> geography (121) information sciences (17) life sciences (361) ocean sciences (34) planetary sciences (14) sciences (1140) social sciences (5) soil sciences (4) chemistry (Earth sciences) -> geochemistry (98) chemistry (life sciences) -> biochemistry (5) scientific careers (8) scientific research bases -> research facilities (2) scientists-at-work photographs (2) -> scientific careers WITH image collections false scorpions -> arachnids (1) bridge scour -> scour (2) scour (2) scrap yards -> disposal sites (2) scrubland ecosystems -> shrubland ecosystems (5) scrublands -> shrublands (2) Se -> selenium (1) sea-floor characteristics (36) sea-ice concentration -> sea ice concentration (2) sea-level change (5) sea-level rise -> sea-level change (5) sea-surface temperature -> sea surface temperature (3) sea anemones -> coelenterates (8) seachannels (seafloor) -> seafloor features (10) deep sea fisheries -> marine fishery resources (2) deep sea fishing -> marine fishery resources (2) seafloor characteristics -> sea-floor characteristics (36) sea floor characteristics -> sea-floor characteristics (36) seafloor features (10) sea floor topography -> bathymetry (27) seagrass -> aquatic vegetation (1) sea ice concentration (2) sea ice cover -> sea ice concentration (2) inland seas -> lakes (25) seas (4) national seashores -> parks (7) seasonal migration -> migration (organisms) (3) sea squirts -> tunicates (2) sea surface temperature (3) seaweeds -> aquatic vegetation (1) second-order administrative divisions -> countries, 2nd order divisions (1) geologic sections -> stratigraphic sections (23) hydrographic sections -> hydrogeology (38) stratigraphic sections (23) sections (geologic) -> stratigraphic sections (23) sections (stratigraphic) -> stratigraphic sections (23) sedimentary rocks (5) alluvial sedimentation -> sedimentation (28) sedimentation (28) sediment geochemistry (3) -> unconsolidated deposits WITH chemical analysis sedimentology (16) eolian sediments -> unconsolidated deposits (13) sediments -> unconsolidated deposits (13) sediment transport (27) segmented worms (2) seismic activity -> earthquake occurrences (39) seismic exploration (1) -> seismic methods WITH natural resource exploration seismic hazard maps (12) -> earthquake occurrences WITH maps and atlases seismic imaging -> seismic methods (37) seismicity -> earthquake occurrences (39) seismicity maps (6) -> earthquake probabilities WITH maps and atlases seismic methods (37) seismic networking (14) seismic profiles -> seismic methods (37) seismic reflection method (5) seismic reflection survey maps (2) -> seismic reflection method WITH maps and atlases seismic refraction method (6) seismic tomography -> tomography (1) seismograms -> seismic methods (37) earthquake seismology (30) -> seismology WITH earthquake occurrences engineering seismology (1) -> seismology WITH engineering sciences seismology (47) seismometry -> seismic methods (37) selenium (1) semi-independent political entities -> political areas (1) optical backscatterance sensing -> optical methods (3) remote sensing (79) space-borne sensing -> remote sensing (79) Special Sensor Microwave/Imager (SSM/I) -> SSM/I (1) DNA sequencing (5) gene sequencing -> DNA sequencing (5) time series analysis (1) ecosystem services -> ecosystem functions (10) settlements -> populated places (8) sewage disposal -> waste treatment and disposal (19) sexing (plants & animals) (2) sexing (plants and animals) -> sexing (plants & animals) (2) mine shafts -> mine sites (7) shaking maps (seismic) (12) -> earthquake occurrences WITH maps and atlases sheepfolds -> agricultural sites (3) ice sheets -> ice masses (7) sheikdoms -> administrative areas (9) shelf edges (ocean) -> continental margins (8) shelf valleys (seafloor) -> seafloor features (10) shellfish (5) animal shelters -> buildings (4) shelters -> buildings (4) continental shelves -> continental margins (8) shelves, continental -> continental margins (8) ship tracks -> transportation features (4) shoals -> bars (physiographic) (1) shops -> buildings (4) shorebirds -> birds (62) shorelines -> coastal zones (43) shores -> coastal zones (43) short grass ecosystems -> grassland ecosystems (13) shrines -> monuments (1) shrubland ecosystems (5) shrublands (2) side-scan sonar methods (20) Sidescan sonar methods -> side-scan sonar methods (20) sierra -> mountain ranges (1) mathematical simulation (2) sinkhole formation -> erosion (26) sinkholes -> physiographic features (87) sinks -> physiographic features (87) siphon (physiographic) -> physiographic features (87) sisal plantations -> agricultural sites (3) agricultural sites (3) dam sites (3) disposal sites (2) ecological research sites (2) highway maintenance sites -> transportation features (4) mine sites (7) observation sites -> research areas (3) parking sites (1) pastoral sites -> agricultural sites (3) refuse disposal sites -> disposal sites (2) test sites -> research areas (3) waste disposal sites -> disposal sites (2) adits (mine sites) -> mine sites (7) reservations (nature sites) -> reserves (2) slag heaps -> disposal sites (2) slides (land) -> landslides (14) slides (natural) -> physiographic features (87) continental slopes -> continental margins (8) slopes -> physiographic features (87) talus slopes -> physiographic features (87) slope stability -> landslide susceptibility assessment (3) slope stability maps (1) -> landslide susceptibility assessment WITH maps and atlases sloughs -> wetlands (26) slues -> wetlands (26) sluices -> hydrographic structures (15) slumps -> mass wasting (16) acid snow -> acid deposition (5) snow -> precipitation (atmospheric) (21) snow and ice cover (19) snowfall -> precipitation (atmospheric) (21) snowfall measurement (10) -> precipitation (atmospheric) WITH field inventory and monitoring snowpack -> snow and ice cover (19) social sciences (5) socioeconomics -> culture and demographics (9) soil chemistry (2) soil formation (3) soil pollution (1) -> soil resources WITH contamination and pollution soil resources (7) soil sciences (4) sonar depth-sounding -> sonar methods (26) side-scan sonar methods (20) Sidescan sonar methods -> side-scan sonar methods (20) sonar methods (26) echo sounding -> sonar methods (26) magnetotelluric sounding -> electromagnetic surveying (8) resistivity sounding -> electrical resistivity logging (2) sounds (bodies of water) -> channels (2) energy sources -> energy resources (50) space-borne sensing -> remote sensing (79) space centers -> research facilities (2) spatial analysis (19) Special Sensor Microwave/Imager (SSM/I) -> SSM/I (1) alien species -> nonindigenous species (44) distribution of species -> biogeography (65) endangered species (13) endemic species (2) exotic species -> nonindigenous species (44) foreign species -> nonindigenous species (44) game species (2) indigenous species -> native species (5) introduced species -> nonindigenous species (44) invader species -> invasive species (26) invasive species (26) keystone species (1) migratory species (12) native species (5) non-indigenous species -> nonindigenous species (44) non-native species -> nonindigenous species (44) nonindigenous species (44) nuisance species (1) species distribution -> biogeography (65) species distribution maps (17) -> biogeography WITH maps and atlases species diversity (3) species geographic range -> biogeography (65) indicator species observation -> ecosystem monitoring (72) specimen collecting (9) collection of specimens -> specimen collecting (9) airborne visible infrared imaging spectrometer -> AVIRIS (1) gamma-ray spectrometric surveying -> aeroradiometric surveying (1) inductively coupled plasma-atomic emission spectrometry -> atomic emission spectroscopy (2) mass spectrometry -> mass spectroscopy (4) atomic emission spectroscopy (2) hand-held field spectroscopy -> handheld field spectroscopy (1) handheld field spectroscopy (1) mass spectroscopy (4) nuclear magnetic resonance spectroscopy -> chemical analysis (29) particle-beam spectroscopy (1) speleology -> geomorphology (33) spiders -> arachnids (1) spillways -> dam sites (3) spits -> bars (physiographic) (1) sponges (2) sport fishing -> recreational fishery resources (3) spring ecosystems -> freshwater ecosystems (15) hot springs -> thermal features (4) village squares -> parks (7) sea squirts -> tunicates (2) SSM/I (1) SSM/I images -> SSM/I (1) sst -> sea surface temperature (3) slope stability -> landslide susceptibility assessment (3) slope stability maps -> landslide susceptibility assessment (3) light stable-isotope analysis -> light stable isotope analysis (9) light stable isotope analysis (9) stable isotope analysis -> light stable isotope analysis (9) bankfull stage -> floods (36) flood stage -> streamflow (108) stream stage -> streamflow (108) state forests -> parks (7) state parks -> parks (7) freely associated states -> political areas (1) United States Government establishments -> buildings (4) bailing stations -> agricultural sites (3) coast guard stations -> buildings (4) experiment stations -> research facilities (2) fire stations -> buildings (4) forest stations -> buildings (4) gaging stations (5) guard stations -> buildings (4) inspection stations -> buildings (4) meteorological stations -> data collection facilities (1) ranger stations -> buildings (4) satellite stations -> data collection facilities (1) stations -> buildings (4) weather stations -> research facilities (2) statistical analysis (11) statues -> monuments (1) stock routes -> transportation features (4) stockyards -> agricultural sites (3) crushed stone -> building stone resources (1) dimension stone -> building stone resources (1) building stone resources (1) stony deserts -> deserts (9) dust storms (1) geomagnetic storms -> magnetic storms (2) magnetic storms (2) storms (21) storm surge (2) stormwater runoff -> runoff (4) strain history -> deformation (geologic) (9) straits -> channels (2) strands -> beaches (2) stratigraphic sections (23) stratigraphy (8) stream-flow monitoring -> stream-gage measurement (109) stream-gage measurement (109) stream-gage monitoring -> stream-gage measurement (109) dry stream beds -> streams (51) stream bends -> streams (51) stream current -> streamflow (108) stream current monitoring -> stream-gage measurement (109) stream discharge (12) stream discharge monitoring -> stream discharge (12) stream ecosystems -> freshwater ecosystems (15) streamflow (108) stream flow -> streamflow (108) streamflow data (67) -> streamflow WITH datasets streamflow modeling (6) -> streamflow WITH mathematical modeling streamflow monitoring -> stream-gage measurement (109) stream flow monitoring -> stream-gage measurement (109) stream gage monitoring -> stream-gage measurement (109) stream mouths -> streams (51) intermittent streams -> streams (51) streams (51) stream stage -> streamflow (108) streets -> roadways (2) strike-slip faults -> faults (8) strip mines -> mine sites (7) strong motion -> earthquake occurrences (39) structural geology (6) earth structure (13) geologic structure (26) structure contours (2) hydrographic structures (15) structures -> buildings (4) student unions -> buildings (4) studios -> buildings (4) isotopic tracer study -> tracer study (2) radioisotope tracer study -> tracer study (2) tracer study (2) study areas -> research areas (3) sub-surface dams -> dam sites (3) subbituminous coal resources -> coal resources (12) subduction -> tectonic processes (20) subsea features -> seafloor features (10) land subsidence (9) subsistence fishery resources (1) substations -> buildings (4) water subsurface -> ground water (156) subsurface maps (90) -> geology WITH maps and atlases suburbs -> populated places (8) ecologic succession -> succession (biological) (2) succession (biological) (2) sugar plantations -> agricultural sites (3) sultanates -> administrative areas (9) public water supply -> domestic water use (4) water supply and demand (52) decision support methods (4) potentiometric surface -> ground-water level (8) temperature (sea surface) -> sea surface temperature (3) surface-water/ground-water interaction -> ground-water and surface-water interaction (1) ground-water and surface-water interaction (1) surface-water level (1) land surface characteristics (31) sea surface temperature (3) surface water (non-marine) (150) surface water/ground water interaction -> ground-water and surface-water interaction (1) surface water quality (24) surficial deposits -> unconsolidated deposits (13) surficial geologic maps (16) -> surficial geologic units WITH maps and atlases surficial geologic units (18) storm surge (2) aeromagnetic surveying (9) aeroradiometric surveying (1) electromagnetic surveying (8) gamma-ray spectrometric surveying -> aeroradiometric surveying (1) land surveying (3) magnetic surveying (4) -> aeromagnetic surveying WITH electromagnetic surveying surveying -> land surveying (3) seismic reflection survey maps -> seismic reflection method (5) geochemical surveys -> chemical analysis (29) magnetic susceptibility analysis (2) landslide susceptibility assessment (3) landslide susceptibility maps (1) -> landslide susceptibility assessment WITH maps and atlases suspended load -> sediment transport (27) suspended material (water) (12) mangrove swamps -> wetlands (26) swamps -> wetlands (26) symbiosis (1) Interferometric Synthetic Aperture Radar (IFSAR) -> IFSAR (4) systematics and taxonomy (16) information system design and development (25) coordinate systems -> map coordinate systems (3) early warning systems -> hazard preparedness (23) geographic coordinate systems -> map coordinate systems (3) grid coordinate systems -> map coordinate systems (3) map coordinate systems (3) river systems (27) geographic information systems (GIS) (17)

Alphabetical index of categories: S