Applied High Resolution Geophysical Methods

The discipline encompassing the use of high-resolution geophysics for obtaining geoengineering survey data has evolved rapidly over the past decades to become an interdisciplinary subject encompassing the fields of Geophysics, engineering, geology, marine geology, oceanography, and civil engineering. While high-resolution geophysical surveys are routinely performed offshore today, this has been so only since the late 1960s. High-resolution geophysical methods are employed in the offshore environment to obtain a comprehensive picture of the sea-floor mor phology and underlying shallow stratigraphy. The purpose of the survey methods is to assist in the design and installation of bottom-supported structures such as drilling and production platforms and pipelines. Drilling structures and pipelines of steel and/or concrete have become behemoths with respect to their size and the complexity of their design in order to withstand, for periods of up to twenty-five years, an extremely harsh environment, including storm waves, strong currents, unstable sea floor conditions, and great water depths. It is therefore of paramount importance that the geometry and physical properties of the sea floor be well understood in order to provide an adequate foundation for the design lives of such structures. On land, engineering foundation data usually may be obtained by visual field inspection and shallow borehole information, but offshore the presence of the water column places certain constraints on geoengineering investigations. High-resolution geophysical methods employed in the acquisition of geoengineering data offshore are defined as the use of seismic sources and receivers that operate at acoustic frequencies greater than 100 Hz.

The Special Issue is focused on recent and upcoming advances in the combined application of remote sensing and applied geophysics. Applied geophysics analyzes the distribution of physical properties in the subsurface for a wide range of geological, engineering, and environmental applications at different scales. Seismic, electrical, magnetic, and electromagnetic methods are among the most applied and well-established geophysical techniques. These methods share the advantages of being non-invasive and exploring wide areas of investigation with respect to conventional methods (e.g., drilling). Geophysical surveys are usually carried out deploying or moving the appropriate instrumentation directly on the ground surface. However, recent technological advances have resulting in the development of innovative acquisition systems becoming more typical of the remote sensing community (e.g., airborne surveys). While applied geophysics mainly focuses on the subsurface, typical remote sensing techniques have the ability to accurately image the Earth’s surface with high-resolution investigations carried out by means of terrestrial, airborne, or satellite-based platforms. The integration of surface and subsurface information is often crucial for several purposes, including the processing of geophysical data, the characterization and time-lapse monitoring of surface and near-surface targets, and the reconstruction of highly detailed and comprehensive 3D models of the investigated areas. Recent contributions showing the added value of surface reconstruction and/or monitoring in the processing, interpretation, and cross-comparison of geophysical techniques for archaeological, environmental, and engineering studies are collected in this book. Pioneering geophysical acquisitions by means of innovative remote systems are also presented.

The first international symposium on NDT-CE (Non-Destructive Testing in Civil Engineering) was held in Berlin, Germany in 1991. Successive symposia were held throughout Europe until 1997. This, the 5th symposium is organized as SEIKEN SYMPOSIUM No. 26, and is sponsored by the Institute of Industrial Science, at the University of Tokyo, Japan. Original objectives of the NDT-CE symposium have been to provide an opportunity for discussing current issues and future perspectives of NDT and for promoting mutual understanding among engineers and researchers. Asia is one of the key regions for further development in NDT and this symposium in Japan will be a good opportunity not only to exchange technical information on NDT, but to promote worldwide friendship between engineers in Asian countries and other nations of the world. This volume contains 70 papers providing the most recent research results and findings. The papers are grouped under the following areas: (1) keynote papers, (2) magnetic / electric, (3) steel structures, (4) integrated test, (5) moisture, (6) strength, (7) acoustic emission, (8) various tests, (9) ultrasonic, (10) impact echo, (11) radar, (12) quality and (13) corrosion / cover.