Obtaining high‐resolution images of the geology and hydrogeology of the subsurface in the depth range from ground level to 50 m is one of the major challenges of modern geophysics. The methods which are commonly used (such as compressional‐wave surveys and ground‐penetrating radar) often suffer from adverse effects caused by the near‐surface conditions, changes in water saturation and various sources of noise. This paper demonstrates some of the advantages offered by the use of shear‐wave seismology and by the combination of shear‐ and compressional‐wave seismic methods in shallow subsurface investigations. Multicomponent shallow seismic tests were carried out at four different sites to examine the effectiveness of different acquisition geometries under a variety of near‐surface geological conditions. Near‐surface conditions encountered at the sites included thick clays, clay/sand sequences overlying Chalk, mudstone overlying granodiorite bedrock and landfill material. Under all conditions, shear‐wave data acquisition was found to have advantages over compressional‐wave acquisition for the investigation of the shallow subsurface. Shear head waves, being unaffected by water saturation, achieved penetration to greater depths at a site in Crewkerne, Dorset where compressional head‐wave penetration was limited to the near‐surface layers. Better vertical resolution was achieved at shallow depths using shear‐wave reflection energy at a landfill site. Shear‐wave reflections from shallow interfaces were in some cases less affected by noise compared with the equivalent compressional‐wave reflections. Combinations of shear‐ and compressional‐wave data recording allowed the measurement of a Poisson's ratio log and gave indications of seismic anisotropy at two sites where dipping clay layers were present.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.