Locating of Sinkhole Extension by Seismic Refraction Tomography and GPR Methods

Abstract

In 2008 a stream flow created a sinkhole near Park City, Utah, creating an irregular-shaped depression in the alluvium about 22 m long, 10 m wide and 6 m deep. The entire discharge of a nearby creek flowed into the sinkhole increasing the size of the sinkhole. A total of 10 GPR and 4 seismic refraction profiles were conducted to find lateral and vertical extensions of this sinkhole. Interpretation of GPR profiles reveals the top of the sinkhole and its lateral extension. The exact shape of the sinkhole and its vertical extension is not clear on the GPR profiles because the high attenuation of the EM waves due to the high water saturation at the study area. However, the seismic refraction tomograms show the exact location of the sinkhole in the X and Z directions. Three anomalies with very low velocities are shown on the tomograms corresponding to the karst/cavernous formations, which are surrounded by low velocity zones corresponding to the highly saturated soils/rocks. It is concluded that near-surface karst and other anomolous feature can be revealed by refraction tomography.

Geotechnical Parameters from Seismic Measurements: Two Field Examples from Egypt and Saudi Arabia

“…In most instances, such determinations were required for only the first 100-200 m of the subsurface (Dobecki and Romig, 1985). Other applications included dam site investigations (Henriet et al, 1983;Dutta, 1984;Kim et al, 2010), groundwater resource exploration (Frohlich, 1974;van Overmeeren, 1975van Overmeeren, , 1980van Overmeeren, , 1981Vandenberghe, 1976;Worthington, 1976Worthington, , 1977Carmichael and Henry, 1977), industrial plant foundation design (Dinis da Gama and Bernardo, 2002), fracture density and uniformity (e.g., Bless and Ahrens, 1977;Sjogren et al, 1979;Hamdi and Smith, 1981), dynamic processes monitoring, which includes groundwater, petroleum, mining, and geothermal provinces either by repeat, active survey methods or by continuous, passive survey monitoring (Dusseault and Nyland, 1982;Bartel, 1982;Holzhausen et al, 1985;Arai and Tokimatsu, 2004;Goertz et al, 2012), clay mapping (Bazin and Pfaffhuber, 2013;Adamczyk et al, 2013;Shan et al, 2014), void detection (Hanafy, 2010;Nolan et al, 2011), and certification (safety) of existing structures such as dams (Bogoslovsky and Ogilvy, 1973a;Davenport and Hadley, 1984;Kim et al, 2010), mines (Fajk, 1983;Hanafy et al, 2009;Hanafy and Schuster, 2011), and concrete shafts (Hearne et al, 1979).…”

Comprehensive Geophysical Study at Wabar Crater, Rub Al‐Khali Desert, Saudi Arabia

“…GPR has been used in many applications, for example, to detect shallow anomalies (Dick et al., 2017; Hanafy, 2010), detect bubbles in ice lake (Fantello et al., 2018), image subsurface layers (Chen et al., 2016), and determine soil‐moisture heterogeneity (Hanafy & Hagrey, 2006). GPR surveys are not usually used to investigate crater impact sites due to its limited depth of penetration.…”

Super‐virtual refraction interferometry: an engineering field data example

“…Refraction traveltime tomography is used to find the detailed structure of near‐surface geology (Zhu et al 1992; Higuera-Diaz et al 2007; Hanafy 2010), as well as to image the gross crustal velocity structure of the earth (Mooney and Weaver 1989; Zelt and Smith 1992; Sheriff and Geldart 1995; Funck et al 2008). A significant problem with current refraction surveys is that they require stronger sources in order to record first arrivals with a high signal‐to‐noise ratio (SNR) at far‐offset traces.…”