Fig. 3From: Local site effects and seismic microzonation around Suban Area, Curup Rejang Lebong, Bengkulu deduced by ambient noise measurementsMap of a natural frequency and b classification of natural frequency into Type I (6.667–20 Hz), Type II (4–6.67 Hz), Type III (2.5–4 Hz), and Type IV (< 2.5 Hz), following Kanai (1983)Back to article page