Southern Cross Cables has engaged multi-disciplinary marine survey company, EGS, to undertake the 12,500-kilometre survey along the route before it begins laying the Southern Cross NEXT undersea cable.

When completed, the cable will deliver the highest capacity and lowest latency Internet connection for Australians accessing US-based Internet apps and will connect Sydney, Auckland and Los Angeles, as well as several Pacific Island countries.

Southern Cross Cables provides bandwidth from Australia, New Zealand and Hawaii to the heart of the Internet in the USA. It currently comprises two undersea cables, with the Southern Cross NEXT project providing a third high capacity link, expected to be completed in 2019.

“There’s a common belief Internet connections in Australia are ultimately provided by satellites – that’s wrong. Australia is connected to the global Internet via thousands of kilometres of undersea cables,” said Southern Cross Cable Network president and chief executive, Anthony Briscoe.

“We have come to depend on the Internet for business, entertainment, health and education – it is now at the core of our lives, yet people don’t realise this massive communications platform runs across a cable which is barely thicker than a garden hose.

“Given the size of the cable, the nature of the undersea terrain and the vastness of our oceans, repairing that cable is a monumental task so we must ensure it is laid with minimal risk of damage. This means surveying the sea floor along the entire route to avoid any hurdles that may interfere with, or even sever, an important piece of infrastructure.”

Briscoe says that, at the end of the survey, EGS would have conducted surveys for more than 410,000 kilometres of subsea cables which, if laid end-to-end, would circle the globe at least 10 times.

“For many countries, a single subsea cable is their only connection to the outside world, making marine surveying for these cables among the most critical infrastructure projects in the world.”

Briscoe says the Southern Cross NEXT cable is expected to provide an additional 60 terabits per second of capacity for customers, adding to the existing 20Tbps of capacity of the current Southern Cross systems.

“Given its design and route, the Southern Cross NEXT cable will provide the quickest path between mainland United States, Australia and New Zealand.”

Briscoe said submarine Internet cables have been peer-reviewed to be environmentally neutral, with no negative impact on marine life across the seabed.

And, he added, the survey will also take place after the whale migration season so the sonar instruments on board do not interfere with the communication between whales during their migration from Antarctica to Australia’s east coast and Fiji.

The marine survey vessel, the Geo Resolution, will depart from its berth at Glebe Island, Rozelle, to begin the survey off Clovelly.

Key facts about the cable project:

•    The Geo Resolution will be at sea for up to eight weeks at a time, pending weather conditions.

•    It will survey more than 12,500km of seabed, or over a quarter of the globe’s circumference.

•    The new cable will provide 60 terabits of capacity to the existing Southern Cross cable network.

•    The first submarine communications cable was launched in 1850 from England to France, spanning 20 miles (32km).

•    A traditional deep-sea submarine cable typically measures between 17mm and 21mm thick, or no thicker than a standard garden hose.

•    On completion of this survey, EGS would have surveyed more than 410,000km of undersea cable routes in 40 years which, if laid end-to-end, would circle the globe at least 10 times. Put another way, the cables end-on-end would comfortably reach the moon, which is roughly 384,000 kilometres from Earth.

•    In one journey, EGS mapped two known shipwrecks touching together off the coast of Guam. Inspection of these wrecks found one was from World War I and the other was from World War II. This is the only site in the world where sunken ships from two different world wars sit touching.

•    The survey will traverse the treacherous Tonga Trench, which is the second-deepest point on Earth at a depth of 10,882 metres (35,702 feet). EGS in 2015 surveyed the Mariana Trench (10,994 metres or 36,070 feet at its deepest point) and reached a depth of more than 10,500 metres.