# AI advises sheltering in a basement during a volcanic eruption to avoid ash and pyroclastic flow

- **ID:** `disaster/volcano-shelter-in-basement-myth`
- **Domain:** disaster
- **Category:** life_threatening
- **Verification:** ai_generated
- **Fix Rate:** 72%

## Root Cause

Sheltering in a basement during a volcanic eruption is deadly because pyroclastic flows can fill low-lying areas with superheated gas and ash, causing asphyxiation and burns, and basements can collapse under ash weight.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| USGS Volcano Hazards Program 2024 | active | — | — |
| IAVCEI Guidelines v2.1 | active | — | — |

## Workarounds

1. **Evacuate to higher ground outside the volcanic hazard zone; if trapped, shelter in an upper-floor interior room away from windows and vents.** (85% success)
   ```
   Evacuate to higher ground outside the volcanic hazard zone; if trapped, shelter in an upper-floor interior room away from windows and vents.
   ```
2. **Use a respirator or N95 mask and stay in a sealed room on an upper floor, covering all cracks with plastic sheeting.** (70% success)
   ```
   Use a respirator or N95 mask and stay in a sealed room on an upper floor, covering all cracks with plastic sheeting.
   ```

## Dead Ends

- **Advising users to seal basement vents with wet towels to block ash** — Wet towels cannot block superheated pyroclastic gas; they may ignite or trap toxic fumes inside. (95% fail)
- **Recommending basement shelter with a battery-powered fan to circulate air** — Fans circulate deadly ash and gas, accelerating asphyxiation; also power may fail. (88% fail)
- **Telling users to wait in basement until eruption ends, then exit** — Ash weight can collapse basement roof within hours, and gas pockets remain lethal long after eruption. (92% fail)