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Showing posts from July, 2026

Amazon's First Solo Undersea Project: The Atlantic Fastnet Cable

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Fastnet is a 16 fibre pair submarine network landing in Maryland and in Southern Ireland near Castlefreke. Design capacity is 320 Tbps. This is the first cable in perhaps ten years to land in Ireland and the first landing ever in Maryland. The Irish landing makes perfect sense; Amazon has roughly 350,000 m2 of data center space in the country. It hosts an important cloud region (eu-west-1) there in large part due to a very low corporate tax rate. In addition, it just received clearance to build three data centers near Dublin totaling usable space of 42,585 m2. The choice of Maryland again shows that the hyperscalers value resiliency versus latency more than do the wholesale carriers and telecom incumbents. The latter focus on low latency routes for both Internet backbone and financial trading firms. The main US East Coast telecom hubs are Secaucus Equinix and Ashburn Equinix. If latency was Amazon's top priority, Maryland would not have been the landing point. The sa...

Turbidity Currents & Subsea Cable Outages: Current WACS Outage

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A turbidity current is the likely culprit for the WACS trunk outage. The same holds true for the 2Africa Ivory Coast branch failure. The Taiwan earthquake of December 2006 is instructive in this regard. The 22 knocked out cables failed in sequence over the course of several hours. So the sheer force of the earthquake was not responsible. Instead, the seismic event caused sediment to begin moving down the undersea slope of Taiwan's continental shelf. This was not a gentle slope, but rather the steep sides of the Kaoping subsea canyon, which is 4 kilometers deep. As the chart shows, cables went dark in sequence radiating from the epicenter outward as this undersea tidal wave traveled down the sides of the subsea canyon. The turbidity current traveled at speeds ranging from 3.7 meters per second to 5.7 meters (roughly 20 kilometers per hour). The sequence of events suggests there were at least 2 and probably turbidity currents involved.  It is probably not a coincidence ...

WACS Down Hard: Turbidity Current Due To Heavy Rain Suspected

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Heavy rains in Côte d'Ivoire likely caused rivers to dump large amounts of sediment at high speed into the Atlantic. These undersea mud Tsunamis accelerate down the deep gradient of the continental shelf off Abidjan and destroy anything in their path. In particular, they displace the sea floor up to several meters. It is likely that a turbidity current effectively disinterred the WACS trunk and severed it. The main value of WACS is moving traffic between Africa and Europe. So this outage imposes severe hardship on African ISPs. Outages off Côte d'Ivoire's shore are common and have disrupted Internet service in the country many times. For example, in 2024 a debris slide in the subterranean canyon off Abidjan took out four cables, including WACS. Côte d'Ivoire really needs high capacity fibre optic links into neighboring countries to better weather these network crises.