The first load stays fast on the simple global map. NASA loads at low zoom. Sentinel-2 HD loads at higher zoom. Extreme World uses global Esri World Imagery at high zoom. Ultra World uses the stable Esri tile layer at extreme zoom. Extreme US still uses USGS NAIP where available.
Performance
Local cache is the safe default. Sentinel-2 HD always uses the local PHP proxy now so browser CORS, CSP, or bad remote responses cannot kill the HD layer. Warm visible tiles preloads the current view in controlled parallel batches.
Live overlays
Radar and earthquakes are global. NWS alerts are U.S. only. Fires use NASA thermal anomaly imagery.
View
Global quick views
Disaster tools
Loading full planet view. Search dock is active: result rows and map-layer pins zoom, and browser location is permission-only.