Subsea cables have been a major focus in the media lately. Just last week at the Quad Foreign Ministers’ meeting in Tokyo, Australia announced the launch of its new Cable Connectivity and Resilience Centre—its contribution to the Quad Leaders’ Partnership for Cable Connectivity and Resilience.

So, what are subsea or undersea cables and why are they important? In this short explainer, Olivia Nelson speaks with ASPI experts Jocelinn Kang and Jessie Jacob about this vital strategic asset, where their vulnerabilities lie, and their role in Australia’s resilience.

Transcript:

Dave: Welcome to stop the world. The ASPI podcast on security and International Affairs. I'm David Wroe

Liv: and I'm Olivia Nelson.

Dave: Now, first of all, Liv, how did I not know that Tassie was completely cut off for a while in 2022?

Liv: Well you aren't alone there, Dave. I'm embarrassed to admit that I also missed that.

Dave: Now I'm choosing not to believe that we just weren't paying attention to our beloved southern state, but rather, there was just a lot going on that year. But thankfully, to explain all of this issue with subsea cables, we've got a short treat for our listeners ahead of our regular Friday programming. Liv, you've spoken with two of our experts here at ASPI, Jocelinn Kang and Jesse Jacob.

Liv: That's right, Dave, I asked Jo and Jess to give us a crash course on the infrastructure we all take for granted, but about which most of us know very little. What are subsea cables? Why are they important, and what are their vulnerabilities?

Dave: So Liv, I've got to tell you, Jo actually explained to me the other day how the internet works, and it was bloody useful. Now you've done the same for subsea cables today, which I'm very grateful for, and it's done quickly, which is just what our busy listeners need. So with no further ado from us, let's dive into the conversation.

Liv: We're hearing more and more about subsea cables, their strategic importance and vulnerabilities. So today, I'm pleased to be joined by ask these Jocelinn Kang and Jessie Jacob to provide a bit of an overview for our listeners. Jo, I might turn to you first, what are submarine cables and why are they important?

Jo: Thanks, Liv. Submarine cables are the conduit that carries almost all the world's international data traffic. So if you're listening to this podcast and you don't live on the Australian mainland, I can almost guarantee that it traveled via a submarine cable to get to you. Now they've always been a strategic asset because they've enabled communications to far off lands, but today they're even more critical because of how much we rely on the data that they transport for businesses, financial markets, military and civilian comms. And of course, things like Facebook and Tiktok and Google search. Submarine cables represent the most cost effective high speed way to transport massive amounts of data.

Liv: So not satellites, Jess? Isn't that how information is communicated globally?

Jess: No, not really, and it's really common to think that, but the vast majority is through these subsea cables. Now, this isn't to say that satellites don't get used. They certainly are. And they're good for remote areas with no cable connectivity. But they don't carry nearly the same amount of data, nor at the same speeds. They're certainly better than nothing, and they have been used as communication backups recently in places like the Ukraine and in Tonga when they lost their subsea cable connectivity. But they don't sort of kick in like a one to one backup like a power generator would if the mains go out. So in that regard, it's better to focus on the resilience of sub cables themselves, rather than satellites.

Jo: To give you an example of the consequences of losing your submarine cable access, we just need to look at Tasmania in 2022 when both the main submarine cables were cut within hours of each other. This caused a widespread outage, and it meant flight delays, loss of access to ATMs and EFTPOS facilities, and that forced businesses to close.

Liv: So Jo, what do these cables look like? Well, I was fascinated to discover that, believe it or not, when they're lying on the seabed, deep in the ocean, they're only about the size of a garden hose. Other parts that are closer to shore, they're a bit thicker because they have more protective armour around them. But the part that actually carries the data, they're thin strands of fibre optic cable, and the rest of the cable, it's actually just to give it structure, power and protection. So the power is for repeaters on the cable, so that they can amplify the light signal down the line.

(Jo misspoke here. It's not structure, but rather insulation)

Liv: And what is the armour for? Am I right to assume that sharks are a threat to national resilience

Jo: In the very early days of having communication cables under the sea, unfortunately, whales used to get entangled in the cable lines, and sharks did actually bite the cables. But since the 1950s the industry started burying the cables in shallower areas to protect them from more frequent bits of anchors and bottom trawling fishing gear. Now, as a result, whales no longer become entangled, and shark bites have reduced. But it really should be said that shark bites, or fish bites, they only made up about 0.1% of cable faults, and since 2006 they've actually been no reported shark related cable faults.

Liv: It's a pretty tiny figure. So what are the biggest threats to the cables?

Jo: Humans.

Jess: --but not humans biting cables. So the most likely cause of damage to cables is actually fishing related. As Jocelinn mentioned earlier, a boat anchor can be dragged across a line, trawling activities and that sort of thing. It's often done by accident, but of course, could be done on purpose, and it would be pretty hard to prove.

Liv: I'm trying to visualise what happens when a cable gets damaged. Say, I'm watching Netflix and a cable gets cut, does my internet suddenly go out and my Sunday night is ruined?

Jess: Well, whether or not your night was ruined kind of depends on what you're watching. But seriously, though, if we remove from this scenario any caching or local data storage aspects and focus on how data moves globally, the data gets rerouted away from the damage cable to a different one. And this is why redundancy is so important and a big part of resilience.

Liv: There's that R word again, resilience. What does resilience look like when it comes to sub cables?

Jo: Well, the way I see it, a resilient submarine cable system is one that operates with minimal disruption and ideally no disruption. But that's in a perfect world. And the reality is, cable disruptions happen, and they will continue to happen. So, resilience means we need to protect the system to try and avoid disruptions, and then in the event a disruption occurs, that we can be in a place where we can quickly recover.

Liv: So how can we do that? Jo?

Jo: There are a few ways we can protect and try to prevent disruptions, physical security for one of the cables themselves, such as putting armour around them. But even more important is protecting the areas where cables are concentrated, so the areas of ocean where they come up to landfall, and the cable landing stations where these cables are connecting to terrestrial networks. We've also mentioned redundancy previously. This is another way, which is about having alternate paths for the data to use in the event of a disruption. So this could mean alternate cable pathways, but also alternate modes of transport, like terrestrial fibre or satellite links. The other element of protection is cybersecurity. So protecting the cable management networks, these are the ones that control the data flows across the submarine cable network. Then, of course, in the event that a disruption occurs, we would want to be able to quickly recover, and this means having an effective and efficient repair capability. So, repair ships to restore that connectivity.

Liv: Okay, so because we don't have major disruptions, I assume that Australia has all of these elements of protection in place?

Jess: Well, more can be done to protect cable landing stations, and I think there's a bit of a choke point, so a clustering of cables in Sydney, but in many other areas, Australia is in a relatively good spot. We have multiple cables, and they generally land in geographically diverse locations. And Australia legislates for the protection of several areas for cables. They're called protection zones. Now, I would say the more problematic issue is the cable repair industry. It's kind of barely hanging on. There are a limited number of repair ships. Those are surprisingly hard to pin down, but out of about 70 cable ships worldwide, about a third of those are designated repair it's an aging fleet and an aging workforce getting a cable repair quickly has a worrying amount of luck involved. You want to have a repair ship nearby and be high on the repair priority list.

Liv: And what about using the other ships you mentioned?

Jo: They're busy and set up to lay new cables as we transition more to cloud and AI and then 6g and everything that enables that's going to mean more data traffic. Now, if all that data traffic wants to move across oceans, that's going to mean more cables

Jess: Mmm exactly, and more cables require more repair ships and a solid cable repair industry. It's the biggest gap Australia has in the resilience piece.

Jo: It's one of those things that when it works, it works, and you won't even know about it, but when it doesn't...

Liv: ...everything grinds to a halt?

Jess: Yeah, I think it's customary in the sub cables field, to quote the US Federal Reserve's Stephen Malphrus here, who spoke in reference to the financial sector and said when the communications networks go down, it doesn't grind to a halt. It snaps to a halt. And he said that nearly 15 years ago.

Liv: Scary stuff. Thanks Jo and Jess for explaining the importance and vulnerabilities of subsea cables to our listeners. I look forward to having you back on the podcast soon.

Jo: Thanks Liv.

Jess: Thanks.

Guests:

⁠Olivia Nelson⁠

⁠Jocelinn Kang⁠

Jessie Jacob