Marine seismic data from the Blake Outer Ridge offshore Florida show strong “bottom simulating reflections” (BSR) associated with methane hydrate occurence in deep marine sediments. We use a detailed amplitude versus offset (AVO) analysis of these data to explore the validity of models which might explain the origin of the bottom simulating reflector. After careful preprocessing steps, we deter...

OBJECTIVES The purpose of this study was to assess individual mechanisms of effort intolerance in patients with heart failure with preserved ejection fraction (HFpEF), heart failure with reduced ejection fraction (HFrEF), or normal cardiac function using combined echocardiography and cardiopulmonary stress testing. BACKGROUND Combined stress echocardiography and cardiopulmonary tests visualiz...

The Virtual Observatory is now mature enough to produce cutting-edge science results. The exploitation of astronomical data beyond classical identification limits with interoperable tools for statistical identification of sources has become a reality. I present the discovery of 68 optically faint, obscured (i.e., type 2) active galactic nuclei (AGN) candidates in the two GOODS fields using the ...

Abstract The application of quantitative interpretation techniques for hydrocarbon prospect evaluation from seismic has become so vital. effective employment these is dependent on several factors: the quality and well data, sparseness physics rock, lithological structural complexity field. This study adopts reflection pattern, amplitude versus offset (AVO), Biot–Gassmann fluid substitution cros...

Angle-gather migration creates seismic images for different reflection angles at the reflector. We formulate an angle-gather time migration algorithm and study its properties. The algorithm serves as an educational introduction to the angle gather concept. It also looks attractive as a practical alternative to conventional common-offset time migration both for velocity analysis and for AVO/AVA ...

Angle-gather migration creates seismic images for different reflection angles at the reflector. We formulate an angle-gather time migration algorithm and study its properties. The algorithm serves as an educational introduction to the angle gather concept. It also looks attractive as a practical alternative to conventional common-offset time migration both for velocity analysis and for AVO/AVA ...

images continue on next page.

Gas-hydrates are crystalline form of water and methane that form at high pressure and low temperature. They have attracted the global attention due to their wide-spread occurrences in the permafrost and outer continental margins; potential as major energy resources; role in climate change etc. It is estimated that the carbon in gas-hydrates is two times the carbon content in fossil fuel reserve...

Azimuthally-dependent P-wave AVO (amplitude variation with offset) responses can be related to open fracture orientation and have been suggested as a geophysical tool to identify fracture orientation in fractured oil and gas reservoirs. A field experiment recently conducted over a fractured reservoir in the Barinas Basin (Venezuela) provides data for an excellent test of this approach. Three li...