Section 3: Integrative Approaches
High-resolution reflection seismic profiles were acquired at two study sites in the Upper Rhine Graben, Germany, to image fault zones in the near-surface domain. The profiles fill the gap left by large-scale 3D seismic imaging focused on targets several kilometers deep. The survey design comprises a very dense sampling of reflection points with frequencies as high as 360 Hz emitted by a small hydraulic vibrator. Dip-moveout processing with poststack migration is required to image the fault systems properly. At the first study site, a broad normal fault zone with a width of about 300 m was imaged. It shows two major faults accompanied by numerous smaller parallel and subparallel faults. At the second study site, the survey reveals a horst structure with two bounding normal faults that branch into several smaller ones with depth. Thicker sedimentary units in the hanging walls of the faults suggest synsedimentary fault growth. Significantly, the high-resolution, 2D near-surface seismic measurements provide deeper insight into the architecture and kinematics of the fault systems than is possible from 3D measurements that are focused on deeper targets.
Figures & Tables
Near-surface seismology and ground-penetrating radar (GPR) have enjoyed success and increasing popularity among a wide range of geophysicists, engineers, and hydrologists since their emergence in the latter half of the twentieth century. With the common ground shared by near-surface seismology and GPR, their significant upside potential, and rapid developments in the methods, a book bringing together the most current trends in research and applications of both is fitting and timely. Conceptually, near-surface seismology and GPR are remarkably similar, and they share a range of attributes and compatibilities that provides opportunities to integrate processing and interpretation workflows, which makes them a perfect pair to share pages in a book.
With growth in numbers and professional emphasis have come sections, focus groups, and even professional societies specifically promoting near-surface geophysics. The emergence of near-surface geophysics groups, beginning in the late 1990s and extending into the early twenty-first century, has fueled a diversity of opportunities for professional collaborations. A range of workshops and shared publications has been the fruit of collaborative efforts. The near-surface community continues to extend and develop methods and approaches necessary to satisfy increasing demands in some of the socioeconomically pertinent disciplines such as civil and environmental engineering and hydrology. This book represents the first formal cooperative effort undertaken by the near-surface communities of the Society of Exploration Geophysicists, the American Geophysical Union, and the Environmental and Engineering Geophysical Society.