Google and Facebook have teamed up to build an 8,000-mile undersea internet cable between Los Angeles and Hong Kong, the longest and fastest internet cable across the Pacific.

The project, a collaboration between the two internet giants, as well as Pacific Light Data Communication and TE SubCom, two telecoms companies, is intended to improve connection speeds between the two continents.

It is one of a number of mammoth undersea cables that Google and Facebook have invested in as they attempt to boost the speed and reliability of their own internet services. Both are also investing heavily in projects to bring internet access to far-flung areas of the world with ambitious projects such as solar-powered internet drones and gigantic balloons.

The Pacific Light Cable Network (PLCN), set to be launched in the summer of 2018, will have an estimated capacity of 120 terabits per second. To put that into perspective, it would be able to transport every book ever written in the space of a few seconds.

It is twice as fast as the quickest trans-Pacific internet cable currently available, which is also backed by Google .

While there are already hundreds of undersea internet cables, technology and telecoms groups are investing heavily in long-distance ones as internet users increasingly rely on high-speed connections and cloud computing, where information must be quickly relayed between computers and enormous physical data centres.

As well as improving direct speeds, they also mean more reliability for internet users, increasing the number of lanes down which data can travel. Google, Microsoft and Amazon are competing fiercely in the fast-growing cloud computing market, which allows companies to outsource infrastructure to them.

“PLCN will bring lower latency, more security and greater bandwidth to Google users in the APAC region,” said Google’s Brian Quigley.

While both companies have a presence in Hong Kong, they are absent in China, which censors the internet strictly.