KERA's Think Forget the cloud, the internet runs on wires
Oct 14, 2025
Samanth Subramanian, an author and journalist known for his work on undersea data cables, dives into the fascinating world of the internet's backbone. He discusses the fragile network of submarine cables that carry 95% of international data, highlighting the Tonga outage caused by a volcanic eruption. Subramanian explains the construction of these cables, their ownership by tech giants, and the legal gaps surrounding them. He also raises important questions about internet access as a fundamental right and the vulnerabilities of our digital connections.
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Volcano Severed Tonga's Only Cable
- Sam Veer smelled sulfur and then lost internet after an undersea volcano eruption severed Tonga's sole cable.
- The eruption's debris damaged the cable on the ocean floor, isolating the country from broadband and calls.
Most Global Data Travels On Seabed Fiber
- About 95% of international data traffic moves through undersea fiber-optic cables, not satellites.
- Voice calls, banking, and huge data flows all rely on the same fragile strand of fiber under the sea.
Cable Construction Varies By Location
- Deep-sea cables have a hair-thin glass core and protective layers, making them roughly garden-hose thick in depth.
- Near shore the cables gain metal shielding to withstand anchors and fishing risks.
