INDEX 769 seismology (continued] European Macroseismic Scale l:502t Fourier spectral data 1:512f general discussion 1:501 intensity scales 1:501, l:502t isoseismal maps 1:502, 1:503f site response analysis 1:511 f velocity profiles 1:512f ground motion prediction techniques 1:506 hazard assessment techniques 1:510, l:513f Mississippi embayment seismic data l:513f, 1:514f Mohorovicic discontinuity 3:647f seismic hazards 1:499, l:500f, 1:510 gravity measurements 1:101-103, l:102f Love waves 5:318-319, 5:333, 5:334f mantle plumes (hotspots) D" layer 3:338 lower mantle 3:338, 3:339f superplumes 3:338, 4:14f transition zone 3:338, 3:338f upper mantle 3:337, 3:337f mantle sampling technique 1:397 mid-ocean ridges 5:405-417 axial magma chamber characteristics 5:408f, 5:409f, 5:410, 5:414f crustal structure 5:411f early research 5:407 schematic diagram 5:413f seismic profile 5:409f seismic velocities 5:410, 5:411 f background information 5:405 crustal thickness 5:415f, 5:416f magma chamber depths 5:415 magma-lens reflections 5:416f Mohorovicic discontinuity characteristics 5:412, 5:414f general discussion 5:412 schematic diagram 5:413f seismic layer 2A characteristics 5:407, 5:408f, 5:409f crustal structure 5:411f, 5:415f crustal thickening 5:41 Of early research 5:406 geological significance 5:407 seismic velocities 5:406f, 5:415f structural variations 5:414, 5:415 f, 5:416f mineral exploration 3:619t moonquakes 5:265, 5:329 P waves 3:194-195, 4:341, 5:151, 5:174f, 5:318-319, 5:332f, 5:332-333 Rayleigh waves 5:318-319, 5:333, 5:334f seismic layer 2A characteristics 5:407, 5:408f, 5:409f crustal structure 5:41 If, 5:415f crustal thickening 5:410f early research 5:406 geological significance 5:407 seismic velocities 5:406f, 5:415f seismic reflection acoustic impedance 5:152, 5:157f amplitude measurements 5:152f basic principles 3:646f, 5:15If, 5:151-152 cratons5:173,5:]74/r crustal structure 3:646 data acquisition general discussion 5:152 multiple signals 5:153, 5:153f offset reflection points 5:154f signal traces 5:153f travel paths 5:154, 5:154f data interpretation depositional environment 5:157 faulting 5:157f general discussion 5:156 migration 5:154 seismic resolution 5:155-156 unconformities 5:156f exploration geophysics 3:190-192 four-dimensional (4D) seismic imaging 5:158 gas hydrates 5:313, S:314f Mohorovicic discontinuity 3:647f Ouachita Mountains 4:69-70 petroleum exploration acoustic impedance 4:315, 5:157f basic principles 4:299f computer-based interpretation systems 4:303f four-dimensional (4D) seismic imaging 4:300-301, 4:302 f, 4:315,5:158 general discussion 4:296, 5:157 hydrocarbon indicators 5:158f offshore seismic surveys 4:3 00f techniques 4:315, 4:318f three-dimensional (3D) seismic imaging 4:297-300, 4:301f, 4:304f, 4:315, 4:319f two-dimensional (2D) seismic imaging 4:296-297, 4:300f receiver arrays 5:153f three-dimensional (3D) seismic imaging 4:310f, 4:315, 5:154, 5:155f,5:156f unconformities 5:545 seismic refraction 1:488, l:491t, l:493f, 5:152, 5:152f seismic waves 3:194f, 5:318-319, 5:320f, 5:332, 5:332f, 5:333f seismographs 1:501, 5:318, 5:319f, 5:320f S waves 3:194-195, 4:341, 5:151, 5:318-319,5:332-333 transport infrastructure determinations 1:488, 1:49 It, 1:493 f See also faulting processes; geophysical techniques Selandian stage background information 5:459-460 biozones 5:460f boundary stratotypes 3:372-373 Brazil l:322f, 1:325f Global Standard Stratotype Sections and Points (GSSPs) 5:506f International Stratigraphic Chart (ICS) 5:517f marine invertebrates 3:380f marine microfossils 3:378f marine vertebrates 3:381f terrestrial invertebrates 3:381f terrestrial vertebrates 3:382f vegetation 3:383f Selenga arc 4:466 selenium (Se) hydrothermal ore deposits 5:394t mineral classification systems 3:501t, 3:502t natural occurrences 3:553t, 3:554 soil concentrations 2:22t toxicity 2:22t Selukwe complex, Zimbabwe 3:491-492 selwynite 5:121-122 sengierite(Cu(UO )(VO )(OH)-3H O) 3:589t sensitive high-resolution ion microprobe technique (SHRIMP) 3:606 sensors active sensors 4:414-420 background information 4:414 lidar 4:414, 4:415f radar altimetry 4:415 applications 4:416 Doppler radar 4:415 earthquakes 4:418 general discussion 4:414 ground motion measurements 4A1794:418f imaging radars 4:415 operating geometries 4:415f radar amplitude images 4:415, 4:417f roughness mapping 4:416 structural/geomorphological mapping 4:416 subsidence 4:419 synthetic aperture radar systems 4:415t, 4:417, 4:418f tectonic processes 4:418 volcanism 4:419, 4:419f sensing techniques 4:414 sonar 4:414, 4:415f passive sensors 4:431-439 background information 4:431 broadband reflective multispectral sensors 4:436 hyperspectral sensors 4:438, 4:438t, 4:43 f passive microwave sensors 4:438, 4:439^ sensor instrumentation across-track multispectral scanners 4:433, 4:433f along-track push-broom scanner 4:435, 4:435f