Real-Time Seismic Data from the Bottom Sea

Abstract

An anchored marine seismometer, acquiring real-time seismic data, has been built and tested. The system consists of an underwater seismometer, a surface buoy, and a mooring line that connects them. Inductive communication through the mooring line provides an inexpensive, reliable, and flexible solution. Prior to the deployment the dynamics of the system have been simulated numerically in order to find optimal materials, cables, buoys, and connections under critical marine conditions. The seismometer used is a high sensitivity triaxial broadband geophone able to measure low vibrational signals produced by the underwater seismic events. The power to operate the surface buoy is provided by solar panels. Additional batteries are needed for the underwater unit. In this paper we also present the first results and an earthquake detection of a prototype system that demonstrates the feasibility of this concept. The seismometer transmits continuous data at a rate of 1000 bps to a controller equipped with a radio link in the surface buoy. A GPS receiver on the surface buoy has been configured to perform accurate timestamps on the seismic data, which makes it possible to integrate the seismic data from these marine seismometers into the existing seismic network.

Development and characterisation of a self-powered measurement buoy prototype by means of piezoelectric energy harvester for monitoring activities in a marine environment

“…Considering the complex trend of the harvested voltage 𝑉 𝑃𝐸𝐻 of the PEH, 𝑉 was estimated as a specific average voltage, indicated with 𝑉 ̅ . It is the accumulated voltage inside the excitation period by the integral average of the rectified signal in equation (7):…”

“…Measurement buoys provide a reading service for chemical and/or physical quantities through sensors and low energy electronics and guarantee a stable communication to the ground through suitable data transfer channels (WI-FI, Bluetooth, GSM) [6], [7]. Although a modest power input is foreseen for supplying the on-board instrumentation, the need to make these devices energy self-sufficient remains open.…”

Design and Performance Evaluation of a “Fixed-Point” Spar Buoy Equipped with a Piezoelectric Energy Harvesting Unit for Floating Near-Shore Applications

“…These include monitoring the concentration of pollutants in both natural and artificial reservoirs and near sewage, as well as the detection of microplastics and their concentration in lagoon or open sea waters [ 2 , 3 ]. In addition, there are also multiple civil protection purposes, including the possibility of detecting anomalous waves or tsunamis that can occur on the coasts [ 4 ]. The scientific literature is rich of solutions that involve the use of floating devices, equipped with a wide range of sensors, for environmental monitoring and adequate telecommunication interfaces.…”

In Design of an Ocean Bottom Seismometer Sensor: Minimize Vibration Experienced by Underwater Low-Frequency Noise

“…Therefore, the OBSs can process the inversion method for exploration of seafloor internal structures and stratum resolution enhancements. For this particular reason, they have been extensively employed in geophysical investigations, detection of natural earthquakes, and offshore oil and gas explorations [ 2 , 3 , 4 , 5 ].…”