any 3d seismic survey can have an acquisition footprint. acquisition footprint is an expression of the surface geometry (most common on land data) that leaves an imprint on the stack of 3d seismic data. often we recognize it as amplitude and phase variations on time slices, which of course display the amplitudes within our data set at a specified two way time (cordsen, 2004). on the other hand,...

Manual stratigraphic interpretation of modern 3-D seismic images is extremely timeconsuming. We present a method based on nonstationary predictive signal/noise separation for automatically recognizing the occurence of a predefined pattern in seismic images. The method is tested on 2-D synthetic and real seismic images, and is shown to reliably detect the presence of unconformities in both.

SUMMARY By cross-correlating recordings of ambient seismic noise, one can retrieve the subsurface reflection response. The quality of the retrieved reflections would depend on the qualities of the ambient noise. In a previous study, we cross-correlated ambient-noise data recorded in a desert area in North Africa and showed that we retrieved reflections. This was done assuming that body-wave noi...

When ambient seismic waves pass near and under an interferometric gravitational-wave detector, they induce density perturbations in the Earth, which in turn produce fluctuating gravitational forces on the interferometer’s test masses. These forces mimic a stochastic background of gravitational waves and thus constitute a noise source. This seismic gravity-gradient noise has been estimated and d...

seismic waves are non-stationary due to its propagation through the earth. time-frequency transformsare suitable tools for analyzing non-stationary seismic signals. spectral decomposition can reveal thenon-stationary characteristics which cannot be easily observed in the time or frequency representationalone. various types of spectral decomposition methods have been introduced by some researche...

[1] Earth’s background vibrations at frequencies below about 0.5 Hz have been attributed to ocean-wave energy coupling into the ground and propagating as surface waves and P-waves (compressional waves deep within the Earth). However, the origin and nature of seismic noise on land at frequencies around 1 Hz has not yet been well studied. Using array beamforming, we analyze the seismic noise fiel...

Cross correlation of ambient seismic noise between four seismographs on tabular iceberg C16, Ross Sea, Antarctica, reveals both the source and the propagation characteristics of signals associated with icebergs. We find that noise correlation functions computed from station data are asymmetric about zero time lag, and this indicates that noise observed on the iceberg originates primarily from a...

the effect of underground cavities in site seismic response was studied over the subway tunnels that are under construction in the city of karaj, using ambient noise measurements as well as numerical modeling. the idea for this research comes from the observation of differences in experimental site transfer function, calculated on more than 100 locations of the city, for the areas near the unde...

An analysis of a passive seismic method for subsurface imaging is presented, in which ambient seismic noise is employed as the source of illumination of underground scatterers. The imaging algorithm can incorporate new data into the image in a recursive fashion, which causes image background noise to diminish over time. Under the assumption of spatially-incoherent ambient noise, an analytical e...