Simulations and design of a sea moored buoy with a real time data undersea seismometer

Abstract

In this paper we present numerical simulations performed prior to the deployment of a real-time seismic buoy in the Alboran Sea (Western Mediterranean), in an active seismic area at 250-300m depth. Due to the inherent difficulties in underwater communications there are not many real time data available and the implementation of seabed seismic real time networks has been neglected for years. Our system mainly consists of a seabed unit (containing the seismometer), an intermediate buoy and a surface buoy (containing the offshore communication system). Physical connection between seabed and surface buoy allows communications and real time data sending through the mooring cable. Two different mooring possibilities using a steel cable and a combination of a steel cable plus an elastomer were analyzed. Numerical simulations were performed for a specific marine buoy taking into account different sea parameters (waves, winds and currents) under usual and extreme conditions.