15 December 2021

As coastal areas become increasingly built up, concerns are growing about levels of artificial light at night (ALAN) and its potential impacts on the marine environment.

Light pollution is well-studied in terms of its effects on the night sky and astronomy, and on terrestrial ecosystems, but until now researchers didn’t know the full extent of ALAN in the oceans.

A new study  ‘A global atlas of artificial light at night under the sea’, funded by the Natural Environment Research Council, maps out areas of the ocean most affected by light pollution. It finds that up to 1.9 million km² of the world’s coastal waters are being exposed to biologically significant levels of ALAN.

The study, published in open access in Elementa: Science of the Anthropocene, brought together researchers from the University of Strathclyde, Plymouth Marine Laboratory, the University of Plymouth, The Arctic University of Norway, Bar-Ilan University, The Interuniversity Institute for Marine Sciences of Eilat and Beit Berl Academic College.

Read more at: https://www.strath.ac.uk/whystrathclyde/news/newglobalatlasmapsoutoceanareasmostaffectedbylightpollution/

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• The exact location has not been revealed but signals can reach submarines across vast distances, researchers say
• A joint experiment with Russia confirmed a ‘ping’ from the facility can also travel effectively underground

By Stephen Chen in Beijing

Published: 10:30pm, 2 Dec, 2021

The biggest antenna on the planet is up and running in central China, opening up long-distance communications with submarines as well as civilian applications, according to engineers and scientists involved in the project.

The exact location of the facility has not been revealed, but is believed to be somewhere in the Dabie Mountains, a protected natural reserve straddling Hubei, Anhui and Henan provinces.

From space, the antenna, which is formed by a network of cables and pylons much like those in ordinary power lines, would look like a giant cross more than 100km (62 miles) long and wide.

But at the ends of those lines, copper nodes are fixed deeply into thick granite. Two powerful underground transmitters – capable of working independently in case one is damaged – charge one megawatt of electrical current and turn the Earth into a giant radio station.

According to a paper published in last month’s Chinese Journal of Ship Research, receiving devices planted 200 metres (700 feet) below the surface on the sea floor can effortlessly pick up signals from the giant antenna 1,300km (800 miles) away – a range that covers the Korean peninsula, Japan, Taiwan and the South China Sea.

The project’s lead engineer Zha Ming and his colleagues, from the Wuhan Maritime Communication Research Institute, said the facility was designed to maintain underwater communications over a total range of 3,000km (1,9000 miles) – enough to reach Guam, the biggest US military base in the western Pacific Ocean.

The extremely low frequency (ELF) facility can generate electromagnetic waves from 0.1 to 300Hz. These radio waves can travel great distances both underwater and below ground.

Read more at: https://www.scmp.com/news/china/science/article/3158162/china-antenna-turns-earth-giant-radio-station-signals-reaching

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The post The Earth’s Submarine Fiber Optic Cable Network appeared first on EMFSA.

Abstract

Many marine animals have evolved sensory abilities to use electric and magnetic cues in essential aspects of life history, such as to detect prey, predators and mates as well as to orientate and migrate. Potential disruption of vital cues by human activities must be understood in order to mitigate potential negative influences. Cable deployments in coastal waters are increasing worldwide, in capacity and number, owing to growing demands for electrical power and telecommunications. Increasingly, the local electromagnetic environment used by electro- and magneto-sensitive species will be altered. We quantified biologically relevant behavioural responses of the presumed, magneto-receptive American lobster and the electro-sensitive Little skate to electromagnetic field (EMF) emissions of a subsea high voltage direct current (HVDC) transmission cable for domestic electricity supply. We demonstrate a striking increase in exploratory/foraging behaviour in skates in response to EMF and a more subtle exploratory response in lobsters. In addition, by directly measuring both the magnetic and electric field components of the EMF emitted by HVDC cables we found that there were DC and unexpectedly AC components. Modelling, restricted to the DC component, showed good agreement with measured results. Our cross-disciplinary study highlights the need to integrate an understanding of the natural and anthropogenic EMF environment together with the responses of sensitive animals when planning future cable deployments and predicting their environmental effects.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7060209/

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As the world begins to move away from petrol and diesel-power cars, there are questions over how the metals needed for batteries in electric vehicles will be sourced.

One possibility is to mine the deep ocean floor. A number of companies are lining up to exploit the minerals found there, but campaigners warn it could have a disastrous impact on the marine environment.

The BBC’s Chief Environment correspondent, Justin Rowlatt, reports.

Filming: Sam Farmar

Edited by : Emily Brooks

https://www.bbc.com/news/av/science-environment-56678976?fbclid=IwAR1SMNpitR5SZF6-O6nN5oBSaU5mLsk3UEefJ2CqYnR12q08ael8frnROnE

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