in seismic exploration studies different types of techniques are used to recognize seismic features in terms of their temporal and spatial spectra. variations in frequency content are sensitive to subtle changes in reflection information (castro de matos et al., 2003). in this study the joint time-frequency analysis is used for seismic texture recognition. discrete wavelet transform (dwt) witho...

self-centering pier (scp) has been viewed as a remarkable accomplishment which is able to sustain major lateral loading with reduced structure damage in seismic engineering. stiffness deterioration observed in experiment is vital for the seismic performance of self-centering concrete pier. in this contribution, the associated stiffness deterioration with respect to the structural damage is mode...

Earthfill dams are man-made geostructures which may be especially damaged by seismic loadings, because the soil skeleton they are made of suffers remarkable modifications in its mechanical properties, as well as changes of pore water pressure and flow of this water inside their pores, when subjected to vibrations. The most extreme situation is the dam failure due to soil liquefaction. Coupled f...

This paper is primarily concerned with seismically imaging details in the mantle at an intermediate scale length between the large scales of regional and global tomography and the small scales of reflection profiles and outcrops. This range is roughly 0.1– 1 kmbab10–10 km, where a is the scale. We consider the implications of several models for mantle evolution in a convecting mantle, and possi...

Seismic studies using well-logging, refraction, and reflection methods were carried out in 1965 in conjunction with a core-sample drilling project in the Ewa Coastal Plain, Oahu, Hawaii. The seismic well-logging technique gave a complicated velocity-depth profile, with higher velocities associated with reef limestone and lower velocities associated with mud deposits. The seismic refraction meth...

Several seismic phases that scattered within a few hundred kilometers of the base of the mantle are observed in a very dense seismic section. The Los Angeles Region Seismic Experiment passive phase array was composed of 88 seismometers placed along a 175 km profile. Records from two deep earthquakes in Tonga and one earthquake near Honshu, Japan show a secondary arrival between clear P and PcP ...