GDACS (Global Disaster Alert and Coordination System)
UN-backed disaster alert system providing official severity assessments:| Event Type | Code | Icon | Sources |
|---|---|---|---|
| Earthquake | EQ | Red circle | USGS, EMSC |
| Flood | FL | Wave | Satellite imagery |
| Tropical Cyclone | TC | Cyclone | NOAA, JMA |
| Volcano | VO | Volcano | Smithsonian GVP |
| Wildfire | WF | Fire | MODIS, VIIRS |
| Drought | DR | Sun | Multiple sources |
| Level | Color | Meaning |
|---|---|---|
| Red | Critical | Significant humanitarian impact expected |
| Orange | Alert | Moderate impact, monitoring required |
| Green | Advisory | Minor event, localized impact |
NASA EONET (Earth Observatory Natural Event Tracker)
Near-real-time natural event detection from satellite observation:| Category | Detection Method | Typical Delay |
|---|---|---|
| Severe Storms | GOES/Himawari imagery | Minutes |
| Wildfires | MODIS thermal anomalies | 4-6 hours |
| Volcanoes | Thermal + SO2 emissions | Hours |
| Floods | SAR imagery + gauges | Hours to days |
| Sea/Lake Ice | Passive microwave | Daily |
| Dust/Haze | Aerosol optical depth | Hours |
Multi-Source Deduplication
When both GDACS and EONET report the same event:- Events within 100km and 48 hours are considered duplicates
- GDACS severity takes precedence (human-verified)
- EONET geometry provides more precise coordinates
- Combined entry shows both source attributions
Filtering Logic
To prevent map clutter, natural events are filtered:- Wildfires: Only events < 48 hours old (older fires are either contained or well-known)
- Earthquakes: M4.5+ globally, lower threshold for populated areas
- Storms: Only named storms or those with warnings