The EllaLink GeoLab is a new technical and collaborative initiative to unite the scientific and telecoms communities for the greater good. The importance of climate monitoring and disaster mitigation is well understood, and the possibility of using submarine cable systems to enable further studies into seismology, volcanology, marine ecology and oceanic conditions has been discussed throughout this century.
The EllaLink GeoLab is the first permanent infrastructure dedicated to scientific research embedded into a commercial Subsea Telecom System.
The EllaLink cable that is being deployed across the Atlantic, between Portugal and Brazil, has opened up an opportunity to integrate a scientific component into a commercial submarine cable system. The GeoLab concept was created as a partnership between EllaLink, EMACOM, FCT, and GÉANT to provide an infrastructure for the benefit of the global scientific community.
Scientists have reported for the first time that it is possible to use submarine cable systems to detect the propagation of seismic waves at the bottom of the ocean. According to their observations, this infrastructure could be used to detect not only earthquakes but also underwater noise.
There are already 1,2 million kilometers of telecommunications cables on the seafloor (covering three times the distance from the Earth to the Moon). Composed of optical fibres, subsea cables carry the majority our telephone communications, SMS and emails. And now they could soon acquire a new function: detecting acoustic and seismic waves.
How are waves detected?
Scientists have installed a laser sensor inland the cable end.
“We send light into the optical fibre and thanks to the small impurities inside the optical fibre, part of the light returns to the beginning of the cable. These light returns allow us to measure variations in elongation of the fibre at any point of the cable. We have measurement points every 20 meters, it is as if the submarine cable were a network of 6,500 seismic sensors”, explains Anthony Sladen, researcher at CNRS and member of the Geoazur laboratory. If seismic waves are detected, the submarine cable also collects acoustic waves from wave movement, boats, etc.
In general, it's very complicated to take measurements in the ocean. Instruments degrade fairly quickly due to corrosion and electronic component reliability. It's also very complicated to communicate with this type of equipment at a depth of 2,500 meters. The submarine cable allows to be as close as possible to the submarine rifts. With the use of submarine cables scientists will be able to detect or prevent an earthquake.
The EllaLink GeoLab initiative aims to provide the scientific community with real-time, accurate and relevant data on seabed conditions along the EllaLink cable route. EllaLink is the first telecoms submarine cable in the world to integrate SMART cable concepts into their design.
