IRIS cable: latency up to 2.4× normal, 9 Oct 2026
What we measured
| Cable | IRIS |
| Segment | Galway, IE → Thorlakshofn, IS |
| Detected | 2026-10-09 21:01 UTC |
| Resolved | 2026-10-16 21:02 UTC |
| Duration | 7d 0h |
| Observed latency | 73 ms |
| Baseline | 32.9 ms · 2.43× |
| Increase | +143% |
| Severity | warning |
Who is affected
Countries where IRIS 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 |
|---|---|---|---|
| Iceland resilience index: 61 · moderate |
1 of 4 cables (25% of submarine diversity) | DANICE, FARICE-1, Greenland Connect | no measurement today; median 76 ms over 30 days (16 routes) |
| Ireland resilience index: 100 · resilient |
1 of 16 cables (6% of submarine diversity) | AEC-1, Beaufort, CeltixConnect-1 (CC-1) +12 more | median 47 ms today vs 61 ms over 30 days (180 routes) - faster |
Dependence is structural (share of the country's submarine cables), not a traffic share: real traffic distribution across cables is not public.
Path analysis
Traffic changed route while latency was elevated. A reroute of this kind usually follows a fault somewhere on the original path.
Cross-probe verdict. Our own cross-check concluded this was an operator reroute, not a cable fault. We publish it anyway, labelled as such.
Timeline
- Alert 2026100902: warning - ratio 2.43x
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- Alert #223 improving: 1/3 consecutive OK
- baseline_shift: Alert #223 Thorlakshofn closed as BASELINE SHIFT after 7+ days: frozen 32.9ms -> new baseline 75.0ms (current 73.0ms). Route changed, not a cable incident.
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.