Incident report · 2026040101
Atlantic Crossing-1 (AC-1) cable: latency anomaly, 1 Apr 2026
Resolved · 4h 58m
What we measured
| Cable | Atlantic Crossing-1 (AC-1) |
| Segment | Sylt, DE → Brookhaven, US |
| Detected | 2026-04-01 14:34 UTC |
| Resolved | 2026-04-01 19:33 UTC |
| Duration | 4h 58m |
| Observed latency | 13.7 ms |
| Baseline | 57.4 ms · 0.24× |
| Increase | +304% |
| Severity | warning |
Who is affected
Countries where Atlantic Crossing-1 (AC-1) comes ashore, how much of their submarine diversity this cable represents, and what our measurements into them show.
| Country | Dependence on this cable | Other submarine cables | What the measurements show |
|---|---|---|---|
| Germany resilience index: 100 · resilient |
1 of 11 cables (9% of submarine diversity) | C-Lion1, Elektra-GlobalConnect 1 (GC1), Fehmarn Bält +7 more | median 56 ms today vs 64 ms over 30 days (1402 routes) - unchanged |
| Netherlands resilience index: 100 · resilient |
1 of 12 cables (8% of submarine diversity) | Amerigo Vespucci, Circe North, COBRAcable +8 more | median 46 ms today vs 54 ms over 30 days (724 routes) - unchanged |
| United Kingdom resilience index: 100 · resilient |
1 of 68 cables (1% of submarine diversity) | 2Africa, Amitie, Apollo +64 more | median 103 ms today vs 74 ms over 30 days (1011 routes) - slower |
| United States resilience index: 100 · resilient |
1 of 122 cables (1% of submarine diversity) | ACS Alaska-Oregon Network (AKORN), AEC-1, Airraq +118 more | median 116 ms today vs 108 ms over 30 days (3282 routes) - unchanged |
Dependence is structural (share of the country's submarine cables), not a traffic share: real traffic distribution across cables is not public.
Path analysis
No usable traceroute data for this window.
Cross-probe verdict. The effect was confined to a narrow set of paths, so a cable-wide fault is unlikely.
Timeline
- Alert #33: warning - Brookhaven
- Alert #33 resolved: Brookhaven
Detection method
Latency is sampled continuously from our probe network. An alert opens when round-trip time to a monitored endpoint holds above its rolling baseline, and closes automatically once it returns. Full method is described on the methodology page.
How to cite
GeoCables (2026). Incident 2026040101: Atlantic Crossing-1 (AC-1). https://geocables.com/incident/2026040101
Embed this map
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