Fig. 3From: Directionally dependent horizontal-to-vertical spectral ratios of microtremors at Onahama, Fukushima, JapanThe microtremor observation points outside of the premises of the Onahama Port Office for Line-A to Line-I. The dotted lines are local roads picked originally from general maps. The gray hatched block surrounded by thicker lines denotes the premises of the Onahama Port Office shown in Fig. 2 Back to article page