Abstract
Uphole and surface seismic refraction surveys were carried out in parts of the Niger Delta, Nigeria, to delineate weathering thickness and velocity associated with aweathered layer. A total of twelve uphole and surface seismic refraction surveyswere shot, computed and analyzed. The velocity of the uphole seismic refraction ranged from 344.8 to 680.3 m/s with a thickness of 5.45 to 13.35 m. Surface seismic refraction ranged from 326.6 to 670.2 m/s and 4.30 to 12.0 m, respectively. The average velocity and thickness ranged from 559.6 to 548.0 m/s and 9.43 to 8.63m with differences of 11.6 m/s and 0.83 m respectively. The VW/VS ratios ranged from 0.955 to 1.059. This indicates that the uphole velocity is higher than the surface refraction velocity leading to low VW/VS values. This is a direct experimental proof of a low velocity zone, confirming the weathered nature of the area. The results of both refraction methods are reliable; the differences in surface refraction values are due to shot point offsets. Based on these findings, it is recommended that shots for seismic surveys should be located above 15.0 m in the area to delineate the effects associated with weathered layers to ensure that will be competent to withstand engineering structures.
Keywords
Subject
Publication details
- DOI
- 10.53539/squjs.vol26iss1pp58-66
- Journal
- Sultan Qaboos University Journal for Science, 26(1), 58-66
- Publisher
- Sultan Qaboos University
- Open access
- Gold open access
- License
- CC BY-ND 4.0
Cite this article
APA 7
Aka, M. U., & Agbasi, O. E. (2021). Delineation of Weathered Layer Using Uphole and Surface Seismic Refraction Methods in Parts of Niger Delta, Nigeria. Sultan Qaboos University Journal for Science, 26(1), 58-66. https://doi.org/10.53539/squjs.vol26iss1pp58-66
MLA 9
Aka, Mfoniso U., and Okechukwu Ebuka Agbasi. "Delineation of Weathered Layer Using Uphole and Surface Seismic Refraction Methods in Parts of Niger Delta, Nigeria." Sultan Qaboos University Journal for Science, vol. 26, no. 1, 2021, pp. 58-66. https://doi.org/10.53539/squjs.vol26iss1pp58-66.
Chicago (author–date)
Aka, Mfoniso U., and Okechukwu Ebuka Agbasi. 2021. "Delineation of Weathered Layer Using Uphole and Surface Seismic Refraction Methods in Parts of Niger Delta, Nigeria." Sultan Qaboos University Journal for Science 26 (1): 58-66. https://doi.org/10.53539/squjs.vol26iss1pp58-66.
Harvard
Aka, M. U. and Agbasi, O. E. (2021) 'Delineation of Weathered Layer Using Uphole and Surface Seismic Refraction Methods in Parts of Niger Delta, Nigeria', Sultan Qaboos University Journal for Science, 26(1), pp. 58-66. doi:10.53539/squjs.vol26iss1pp58-66.
Vancouver
Aka MU, Agbasi OE. Delineation of Weathered Layer Using Uphole and Surface Seismic Refraction Methods in Parts of Niger Delta, Nigeria. Sultan Qaboos University Journal for Science. 2021;26(1):58-66. doi:10.53539/squjs.vol26iss1pp58-66
IEEE
M. U. Aka, and O. E. Agbasi, "Delineation of Weathered Layer Using Uphole and Surface Seismic Refraction Methods in Parts of Niger Delta, Nigeria," Sultan Qaboos University Journal for Science, vol. 26, no. 1, pp. 58-66, 2021, doi: 10.53539/squjs.vol26iss1pp58-66.