Sirius South: 1.37× baseline latency
What we measured
| Cable | Sirius South |
| Segment | Dublin, IE → Blackpool, GB |
| Detected | 2026-03-28 19:33 UTC |
| Resolved | 2026-03-29 06:29 UTC |
| Duration | 9h 56m |
| Observed latency | 42.1 ms |
| Baseline | 30.8 ms · 1.37× |
| Increase | +149% |
| Severity | warning |
Who is affected
Countries where Sirius South 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 |
|---|---|---|---|
| Ireland resilience index: 97 · resilient |
1 of 16 cables (6% of submarine diversity) | AEC-1, Beaufort, CeltixConnect-1 (CC-1) +12 more | average 37 ms over the last day vs 62 ms over 30 days - faster |
| United Kingdom resilience index: 97 · resilient |
1 of 67 cables (1% of submarine diversity) | 2Africa, Amitie, Apollo +63 more | median 82 ms today vs 69 ms over 30 days (102 routes) - slower |
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. Multiple independent probes saw the same degradation, so this was not a local artefact.
Timeline
- Alert #27: warning - Blackpool
- Alert #27 resolved: Blackpool
Evidence
RIPE Atlas measurements behind this detection, verifiable independently:
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.