No	Researchers	Year	Region	Kappa values range
1	Anderson and Hough	1984	California	Alluvium: k = 0.066 s + (0.000126 s/km⁻¹)R
				consolidated sediments: k = 0.065 s + (0.000172 s/km⁻¹)R
				rock: k = 0.040 s + (0.000380 s/km⁻¹)R
2	Hatzidimitriou et al.	1993	Greece	K_0average = 0.057
3	Castro et al.	1996	Friuil, Italy	K_0average = 0.03
4	Hough et al.	1988	Anza array in southern California	k₀ = 0.0003≈0.0181
5	Bay et al.	2003	Switzerland	k₀ = 0.015
6	Ghasemi et al.	2003	Bam, Iran	k = 0.0187 + 0.0004R_epi (R² = 0.603)
7	Bay et al.	2005	Switzerland	k₀ = 0.0125
8	Morasca et al.	2006	Western Alps	k₀ = 0.012
9	Douglas et al.	2010	Mainland France	k_rock = 0.0207 + 0.000175R_epi
10	Ktenidou et al.	2013	Aegion, southwestern part of the Gulf of Corinth Greece	k_soil = 0.0270 + 0.000175R_epi
11	Ktenidou et al.	2015	EUROSEISTEST valley, Northern Greece	Station at the valley centre
				k_,as = 0.061 + 0.00048R_e ± 0.011 (R² = 0.78)
				Downhole stations; k_r_,as = 0.021 + 0.00048R_e ± 0.008 (R² = 0.47)
12	Samaei et al.	2016	Ahar-Varzagchan, Iran	$k (R) = {\begin{cases} 0.043 R \leq 40 (km) \\ 0.0126 + 0.00076 R 40 \leq R \leq 130 (km) \\ - 0.055 + 0.00128 R R \geq 130 (km) \end{cases}$
13	Kumar et al.	2018	Western India	Epicentral distance: k_e = 0.0208 + 0.00004458R_epi Hypocentral distance: k_h = 0.0381 + 0.00009021R_hip