Seismic anisotropy is an efficient way to investigate the deformation field within the upper mantle. In the framework of rigid tectonic plates, we make use of recent tomographic models of azimuthal anisotropy for deriving the best rotation pole of the Pacific plate in the uppermost 200km of the mantle. It is found to be in good agreement with current plate motion (NUVEL1, HS3 and NNR). However,...

This paper reports on the damage of Wushi bridge in a recent Taiwan 921 earthquake. Damage to Wushi bridge appeared in the superstructure, the substructure and the approaches. Typical types of damage are discussed and illustrated in this paper. A review of the bridge design specifications in Taiwan is also presented to give the background on the seismic design of Taiwan highway bridges.

Pletser et al. performed a seismic-refraction survey on Devon Island with the goal of assessing the feasibility of astronauts carrying out such operations on Mars to detect subsurface water. We demonstrate that the seismic analysis is fundamentally flawed. The survey performed in this test will likely bear little resemblance to future crewed geophysical surface operations, and better methods ex...

The period of vibration is a fundamental parameter in the force-based design of structures as this parameter defines the spectral acceleration and thus the base shear force to which the building should be designed. This paper takes a critical look at the way in which seismic design codes around the world have allowed the designer to estimate the period of vibration for use in both linear static...

Masonry structures are complex systems that require a thorough and detailed knowledge and information regarding their behaviour under seismic excitations. Appropriate modelling of a masonry structure is a prerequisite for a reliable earthquake resistant design or assessment. However, modelling a real structure to a robust quantitative (mathematical) representation is a very difficult, complex a...

We discuss three approaches to seismic interferometry and compare their underlying assumptions. In the first approach the reflection response is reconstructed by cross-correlating the responses of many uncorrelated noise sources. In the second approach a depth image is obtained from the response of a single source, recorded by many receivers. In the third approach the Green’s function is recons...

Time-lapse (4D) seismic data sets have proven to be extremely useful for reservoir monitoring. Seismic-derived impedance estimates are commonly used as a 4D attribute to constrain updates to reservoir fluid flow models. However, 4D seismic estimates of P-wave impedance can contain significant errors associated with the effects of seismic noise and the inherent instability of inverse methods. Th...

Coda-wave interferometry is a technique to detect small seismic velocity changes using phase changes in similar waveforms from repeating natural or artificial sources. Seismic interferometry is another technique for detecting seismic velocity changes from cross-correlation functions of ambient seismic noise. We simultaneously use these two techniques to clarify seismic velocity changes at Sakur...

Seismic modeling aids the geophysicists to have a better understanding of the subsurface image before the seismic acquisition, processing, and interpretation. In this regard, seismic survey modeling is employed to make a model close to the real structure and to obtain very realistic synthetic seismic data. The objective of this study is to analyze the resolution and illumination of the fault by...

3D visualization is an important link in seismic data processing and interpretation, and the development of the microcomputer system of 3d visualization software for seismic data is very necessary. This paper uses MFC (Microsoft Programming Interface) and VTK (Visualization Toolkit) building three-dimensional scene, realizing the 3d seismic data field Visualization display system and determinin...