Near real time seismic data from the coastal ocean

A moored-buoy system for collecting near real-time seismic data from the coastal ocean has been developed and will be deployed for its initial field trial in the fall of 2016. The technology that makes possible the near real time telemetry of seismic data is the inductive modem technology. This type of data telemetry provides a solution that is convenient, economical, reliable, and flexible. We present results of a prototype system that demonstrate the feasibility of this concept. It will transmit continuous data at a rate of about 1000 bps to a radio link in the surface buoy. A GPS receiver on the surface buoy will be configured to perform accurate and synchronized timestamps on the seismic data on the sea surface, which will make it possible to include data from these undersea systems in the existing seismic data network. Power to operate the system will be supplied by solar panels and rechargeable batteries on the surface buoy and batteries on OBS.Peer ReviewedPostprint (published version

INTMARSIS: A Real Time Seafloor Seismic Observatory

In this paper we present the current status of a marine seismometer to be deployed in the Alboran Sea in September 2016. The design consists of a seafloor unit and a surface buoy connected by a cable. This design pretends to be an alternative to OBS (Ocean Bottom Seismometer) in shallow waters (depth < 500 m). In contrast to OBS, a physical connection between the seafloor unit and the surface buoy allows real time data processing and offshore communication. Even though an umbilical cable seems to be the more obvious alternative, the low energetic consumption of the seafloor unit and the recent improvements in inductive communications open a very interesting new possibility using steel cables.Postprint (author's final draft

Coupling of geophone in the ocean bottom

We can obtain the performance of the geophone in the sediment to know its coupling in the bottom sea. This paper is about the parameters of coupling in order to obtain the response of geophone through the frequency and the amplitude of the vibrations. The use of the shake table permits to obtain the transfer function of coupling between the geophone and the sediment sea without using a detailed model of interaction OBS/seabed

Good practice guide for calibrating a hydrophone "in situ" with a non-omnidirectional source at 10 kHz (26-34)

The aim of this paper is to provide the basis for the calibration of a hydrophonePeer ReviewedPostprint (published version

Underwater seismometer validation

This work verifies and validates the calibration in a marine geophone by means of a hyperbaric chamber before and after the pressure underwater laboratory test. The objective is to characterise the transfer function according to the frequency of coupling between the geophone and the sediment. It is possible to observe the geophone coupling variations through the sediment after the test inside the water pressure at the equivalent of 200 metres depth.Peer Reviewe

Geophone calibration procedure for ocean bottom seismometers (OBS)

Peer Reviewe

Geophone calibration procedure for ocean bottom seismometers (OBS)

Peer Reviewe

Underwater seismometer validation

This work verifies and validates the calibration in a marine geophone by means of a hyperbaric chamber before and after the pressure underwater laboratory test. The objective is to characterise the transfer function according to the frequency of coupling between the geophone and the sediment. It is possible to observe the geophone coupling variations through the sediment after the test inside the water pressure at the equivalent of 200 metres depth.Peer ReviewedPostprint (published version

Decimator filter based on B-splines

Peer Reviewe