Fig. 2From: Directionally dependent horizontal-to-vertical spectral ratios of microtremors at Onahama, Fukushima, JapanThe microtremor observation points within the premises of the Onahama Port Office for a Line-1 to Line-3 and b Line-4 to Line-7. The blue and green circles denote the strong motion observation site and the boring point by the PRENOLIN Project (Régnier et al. 2015), respectivelyBack to article page