Project Massawa: Attenuation of Low-Frequency Sound in the Red Sea

Extensive measurements in the Atlantic Ocean (4°C) have shown the attenuation of sound below 10 kHz to be anomalously high. In order to determine the temperature dependency of this anomaly, a similar experiment has been conducted in the warmer water (22°C) of the Red Sea. The results show a shift in the apparent relaxation frequency from the 1 kHz observed in the Atlantic to 1.5 kHz, resulting in higher values of the attenuation coefficients in the range 1–6 kHz. The computed activation energy is comparable with that expected for hydrogen bonding.