seismic profiling
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ment layers, usually to depths of a few tens of meters below the sea floor. The
echoes of the signals are detected by hydrophones, which are sensitive to
variations in pressure. Several hydrophone groups are incorporated into a
long cable (streamer) towed behind the ship. Depth controllers keep the cable
horizontal at a proper depth. The entire streamer may be 1 to 3 km long.
~echosounding.
seismic profiling gathering of seismic data along a line. The term is usually
restricted to the seismic reflection shooting technique.
seismic stratigraphy study of the stratification and sedimentary features as interpreted from seismic surveys.
seismic survey method for mapping subsurface geologic structures by initiating
an acoustic pulse at a source point and observing the propagation of the seismic waves. There are two main methods to perform a seismic survey: seismic
refraction shooting is a method not commonly used now in crustal studies,
because seismic reflection shooting gives greater continuity and takes far less
effort. However, the reflection technique is not capable of reaching the deepest layers, and the study of, e.g., the Mohorovicic discontinuity requires refraction
shooting or earthquake studies.
seismic velocity rate of propagation of a seismic wave, usually measured in km S-I.
The wave velocity depends on the type of wave, as well as the elastic properties and density of the Earth material through which it travels.
seismic wave general term for all elastic waves generated by earthquakes or artificial sources (~seismic instruments). It includes body waves and surface waves.
Surface waves travel along the surface of the earth and are less important
seismic exploration. Body waves, however, travel through the interior of the
earth and are affected by subsurface interfaces. A body wave may be either
longitudinal (P-wave) or transverse (S-wave).
SEM ~scanning electron microscope.
semidiurnal tide a tide with high and low water twice every lunar day. ~harmonic
analysis of tides.
sensitivity analysis ~models.
sessile a way of life exploited by benthic organisms or organisms living attached
to the substratum. The organisms are termed seston (has also a different
meaning, ~seston). Sessile organisms may be found in different groups such
as macro algae, sponges, corals, bryozoans, oysters, and barnacles. There are
290
ment layers, usually to depths of a few tens of meters below the sea floor. The
echoes of the signals are detected by hydrophones, which are sensitive to
variations in pressure. Several hydrophone groups are incorporated into a
long cable (streamer) towed behind the ship. Depth controllers keep the cable
horizontal at a proper depth. The entire streamer may be 1 to 3 km long.
~echosounding.
seismic profiling gathering of seismic data along a line. The term is usually
restricted to the seismic reflection shooting technique.
seismic stratigraphy study of the stratification and sedimentary features as interpreted from seismic surveys.
seismic survey method for mapping subsurface geologic structures by initiating
an acoustic pulse at a source point and observing the propagation of the seismic waves. There are two main methods to perform a seismic survey: seismic
refraction shooting is a method not commonly used now in crustal studies,
because seismic reflection shooting gives greater continuity and takes far less
effort. However, the reflection technique is not capable of reaching the deepest layers, and the study of, e.g., the Mohorovicic discontinuity requires refraction
shooting or earthquake studies.
seismic velocity rate of propagation of a seismic wave, usually measured in km S-I.
The wave velocity depends on the type of wave, as well as the elastic properties and density of the Earth material through which it travels.
seismic wave general term for all elastic waves generated by earthquakes or artificial sources (~seismic instruments). It includes body waves and surface waves.
Surface waves travel along the surface of the earth and are less important
seismic exploration. Body waves, however, travel through the interior of the
earth and are affected by subsurface interfaces. A body wave may be either
longitudinal (P-wave) or transverse (S-wave).
SEM ~scanning electron microscope.
semidiurnal tide a tide with high and low water twice every lunar day. ~harmonic
analysis of tides.
sensitivity analysis ~models.
sessile a way of life exploited by benthic organisms or organisms living attached
to the substratum. The organisms are termed seston (has also a different
meaning, ~seston). Sessile organisms may be found in different groups such
as macro algae, sponges, corals, bryozoans, oysters, and barnacles. There are