[1] We analyze short-period precursory energy to PP that can be observed in seismograms in the distance range from 95 to 105 to infer the behavior of subducted slabs beneath western Pacific subduction zones. PP is a P wave once reflected at the free surface between the source and receiver. Using high-resolution seismic array techniques, we analyze the incidence angle, timing, and azimuth of the...

In this paper, we propose a method for the automatic 4 identification of P -phase arrival based on the distribution of local 5 maxima (LM) in earthquake seismograms. The method efficiently 6 combines energy and frequency characteristics of the LM distri7 bution (LMD). The P detection is mainly based on the energy of 8 a seismic event in the case the earthquake has higher amplitude 9 than seismi...

Recently, there have been a lot of earthquakes in Japan. It is necessary to promote seismic isolation devices for buildings. The devices have been hardly diffused in attached houses, because the devices are very expensive. We should develop a low-cost seismic isolation device for detached houses. We suggested a new seismic isolation device which uses a two-layer circular tube as a unit. If hyst...

[1] To accurately estimate the seismic energy radiated in an earthquake, it is important to use appropriate corrections for path and source effects. Using slip models obtained by inversion of seismic data, we examine the effect of directivity on estimates of radiated energy and develop a method to correct for this source effect. From our calculations we suggest that the directivity correction f...

Seismic attribute analysis is important in subsurface data interpretation, such as seismic which could involve stratigraphic and structural interpretation. This interpretation often hampered by resolution and, sometimes, human inability to identify a subtle feature on the seismic. These factors have frequently led poor of geologic features. Thus, an integral approach studying patterns hydrocarb...

Subsurface characterization activities undertaken in collaboration with the Southwest Regional Carbon Sequestration Partnership on their San Juan Basin pilot test include acquisition of geophysical logs, time lapse VSP and analysis of 3D seismic data from the site. The project is funded by the U.S. Department of Energy and is managed by the National Energy Technology Laboratory.CO2 injection be...

In this study, the performance of triangular added damping and stiffness (TADAS) dampers combined with curved dampers (Curved-TADAS damper) is evaluated in moment resisting steel frame (MRSF). These dampers are passive and install in the beam-column connection region. Variable parameters of this study involve the width of curved damper (50, 75 and 100 mm), the thickness of TADAS damper (5 and 1...