> ## Documentation Index
> Fetch the complete documentation index at: https://www.worldmonitor.app/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Infrastructure Cascade Analysis

> Dependency graph modeling for critical infrastructure and undersea cable monitoring, visualizing how disruptions cascade across countries and systems.

Critical infrastructure is interdependent. A cable cut doesn't just affect connectivity; it creates cascading effects across dependent countries and systems. The cascade analysis and cable monitoring systems visualize these dependencies and provide early warning of disruptions.

## Dependency Graph

The system builds a graph of **350 infrastructure nodes** and dependency edges:

| Node Type           | Count | Examples                                                 |
| ------------------- | ----- | -------------------------------------------------------- |
| **Undersea Cables** | 86    | MAREA, FLAG Europe-Asia, SEA-ME-WE 6                     |
| **Pipelines**       | 88    | Nord Stream, Trans-Siberian, Keystone                    |
| **Ports**           | 62    | Singapore, Rotterdam, Shenzhen                           |
| **Chokepoints**     | 9     | Suez, Hormuz, Malacca, Gibraltar, Bosphorus, Dardanelles |
| **Countries**       | 105   | End nodes representing national impact                   |

## Cascade Calculation

When a user selects an infrastructure asset for analysis, a **breadth-first cascade** propagates through the graph:

```
1. Start at source node (e.g., "cable:marea")
2. For each dependent node:
   impact = edge_strength × disruption_level × (1 - redundancy)
3. Categorize impact:
   - Critical: impact > 0.8
   - High: impact > 0.5
   - Medium: impact > 0.2
   - Low: impact ≤ 0.2
4. Recurse to depth 3 (prevent infinite loops)
```

## Redundancy Modeling

The system accounts for alternative routes:

* Cables with high redundancy show reduced impact
* Countries with multiple cable landings show lower vulnerability
* Alternative routes are displayed with capacity percentages

## Example Analysis

**MAREA Cable Disruption**:

```
Source: MAREA (US ↔ Spain, 200 Tbps)
Countries Affected: 4
- Spain: Medium (redundancy via other Atlantic cables)
- Portugal: Low (secondary landing)
- France: Low (alternative routes via UK)
- US: Low (high redundancy)
Alternative Routes: TAT-14 (35%), Hibernia (22%), AEConnect (18%)
```

**FLAG Europe-Asia Disruption**:

```
Source: FLAG Europe-Asia (UK ↔ Japan)
Countries Affected: 7
- India: Medium (major capacity share)
- UAE, Saudi Arabia: Medium (limited alternatives)
- UK, Japan: Low (high redundancy)
Alternative Routes: SEA-ME-WE 6 (11%), 2Africa (8%), Falcon (8%)
```

## Use Cases

* **Pre-positioning**: Understand which countries are most vulnerable to specific infrastructure failures
* **Risk Assessment**: Evaluate supply chain exposure to chokepoint disruptions
* **Incident Response**: Quickly identify downstream effects of reported cable cuts or pipeline damage

## Undersea Cable Activity Monitoring

The dashboard monitors real-time cable operations and advisories from official maritime warning systems, providing early warning of potential connectivity disruptions.

### Backed by endpoints

| Method | Route                                     | What it feeds                                                                                                                                                                                                          |
| ------ | ----------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `GET`  | `/api/infrastructure/v1/get-cable-health` | Cable health map/tooltips and cascade context. `fetchCableHealth()` calls this RPC when the cable layer is active, keeps a 1-minute local cache, and the server response is backed by Redis plus NGA warning analysis. |

### Data Sources

| Source              | Coverage       | Data Type                 |
| ------------------- | -------------- | ------------------------- |
| **NGA Warnings**    | Global         | NAVAREA maritime warnings |
| **Cable Operators** | Route-specific | Maintenance advisories    |

### How It Works

The system parses NGA (National Geospatial-Intelligence Agency) maritime warnings for cable-related activity:

1. **Keyword filtering**: Warnings containing "CABLE", "CABLESHIP", "SUBMARINE CABLE", "FIBER OPTIC" are extracted
2. **Coordinate parsing**: DMS and decimal coordinates are extracted from warning text
3. **Cable matching**: Coordinates are matched to nearest cable routes within 5° radius
4. **Severity classification**: Keywords like "FAULT", "BREAK", "DAMAGE" indicate faults; others indicate maintenance

### Alert Types

| Type               | Trigger                            | Map Display               |
| ------------------ | ---------------------------------- | ------------------------- |
| **Cable Advisory** | Any cable-related NAVAREA warning  | Yellow marker at location |
| **Repair Ship**    | Cableship name detected in warning | Ship icon with status     |

### Repair Ship Tracking

When a cableship is mentioned in warnings, the system extracts:

* **Vessel name**: CS Reliance, Cable Innovator, etc.
* **Status**: "En route" or "On station"
* **Location**: Current working area
* **Associated cable**: Nearest cable route

This enables monitoring of ongoing repair operations before official carrier announcements.

### Why This Matters

Undersea cables carry 95% of intercontinental data traffic. A cable cut can:

* Cause regional internet outages
* Disrupt financial transactions
* Impact military communications
* Create economic cascading effects

Early visibility into cable operations, even maintenance windows, provides advance warning for contingency planning.