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...

This paper examines the survey of tall buildings in an emergency context like in the case of post-seismic events. The after-earthquake survey has to guarantee time-savings, high precision and security during the operational stages. The main goal is to optimize the application of methodologies based on acquisition and automatic elaborations of photogrammetric data even with the use of Unmanned A...

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...

There are rich geothermal resources in China and they widely distributed. After years of continuous exploration production, most the shallow have been explored current mainly focuses on deep ones. Among a great many geophysical methods, seismic survey is effective means resource but its weak reflection signal, low S/N ratio poor imaging thermal reservoirs due to geological conditions restrict p...

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...

HOUSTON–Technology advances such as wide-azimuth/full-azimuth (WAZ/FAZ) acquisition, reverse-time migration (RTM) and iterative salt imaging in model building have greatly improved subsalt image quality. In the Gulf of Mexico, steeply dipping three-way closures are familiar subsalt targets. However, despite these imaging improvements, some of these targets remain poorly imaged. The fundamental ...