id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
esrj-33851	Farooq, Muhammad; et, al	Subsurface cavity detection in a karst environment using electrical resistivity (er): a case study from yongweol-ri, South Korea	2012	8	.pdf	application/pdf	4120	60	4	It also shows weak rock and/or clay-filled cavities and that the corresponding resistivity images identified low resistivity areas within the study region Subsurface cavity detection in a karst environment using electrical resistivity (er): a case study from yongweol-ri, South Korea 81 0 5 10 15 20 25 Line 5 BH 106 D ep th (m et er ) Distance (meter) 10 20 30 40 50 60 70 80 figure 8. Inverted field resistivity data obtained from survey lines 1 to 4 Line 1 Line 2 Line 3 Line 4 (RMS) misfit between observed and model pseudosection is achieved Re- sistivity differences normally correspond to changes in subsurface materi- als or pore fluids Synthetic modelling Synthetic modelling was carried out prior to field data acquisition in this study for deciding on a suitable electrode array to be used during data acquisition EM2DMODEL numerical forward model software (South Ko- rean Institute of Geosciences and Mineral Resources’ Geo-electrical Imag- ing Laboratory) was used to simulate subsurface cavity electrical response A finite element algorithm was used to calculate direct response (apparent resistivity) from a set of resistivity models intended to reflect cavity area pat- tern The resulting apparent resistivity from forward modelling was input into DIPRO software and inverted into earth resistivity models The for- ward model tested (Figure 2) had three layers having 20 -m, 70 -m and 500 -m resistivity; 70 -m was selected to represent the top layer of overbur- den material (weathered soils), 20 -m a subsurface cavity in the bedrock and 500 -m bedrock resistivity (i e limestone)	cache/esrj-33851.pdf	txt/esrj-33851.txt