24 hours pattern of underwater ambient noise level in Nowshahr Port, Caspian Sea

Subject Areas : Marine Physics

A. M. Arasteh ¹ (Faculty of Marine Science & Technology, Islamic Azad University, North Tehran Branch)
I. Mehrabi ² (Imam Khomeini Marine Sciences University, Nowshahr, Mazandaran)
M. R. Soheilifar ³ (Imam Khomeini Marine Sciences University, Nowshahr, Mazandaran)

Received: 2012-10-08 Accepted : 2016-05-06 Published : 2012-05-21

Keywords: Caspian Sea, underwater acoustics, ambient noise, Nowshahr Port,

Abstract :

In this research, we measured underwater ambient noise in Nowshahr Port using standard devices and analyzers during a 24 hours period. Proper processing capabilities of analyzers made some comparisons between obtained noise level spectrum and noise generating sources through related frequency range. Then analytic evaluation of importance of these sources in generating noise and its transmission was performed. Results showed that although Nowshahr Port is not a busy area in Caspian Sea referring to statistical reports, but measured underwater noise levels showed the contrary, a high shipping traffic. The relatively high level of noise compared to shipping traffic, can be because this port is located in shallow waters and affected by coastal boundaries that made resonance in underwater sound transmission.