The Response of Narrow-Mouthed Harbors in a Straight Coastline to Periodic Incident Waves

The response to low-frequency periodic plane incident waves of a harbor connected by a narrow channel to the open sea is studied using linearized, constant depth, shallow water wave theory. Particular attention is paid to those frequencies close to the natural frequencies of the harbor basin and to those critical incident frequencies at which a maximum response is found. The theory developed is applicable as long as the width of the channel, and therefore, the harbor entrance is small compared to the incident wavelength and to the characteristic dimensions of the harbor basin. Significant amplifications are found at certain incident wavelengths which do not necessarily correspond to the natural frequencies of the harbor basin and a peculiar effect of the length of the entrance channel on the magnitude of the amplification; values of these critical incident wavelengths are noted.