validate-cave

name	validate-cave
description	Test speleothem earthquake detection against modern earthquake catalogs. Use when validating methodology, checking if cave detects known earthquakes, building validation matrix. Triggers on "validate cave", "test detection", "modern earthquake validation", "blind test".

/validate-cave - Modern Earthquake Validation Skill

Purpose

Systematically test if a speleothem cave record detects known modern earthquakes. This validates the paleoseismic methodology and builds the 50+ validation matrix.

Usage

/validate-cave <cave_name_or_entity_id> [--start YEAR] [--end YEAR] [--radius KM]

Examples:

/validate-cave CRC-3                     # Crystal Cave (California)
/validate-cave YOKI --start 1970 --end 2010
/validate-cave "Lapa Grande" --radius 50
/validate-cave Ko-1                      # Kocain (Turkey)

Workflow

Step 1: Identify Cave & Get Coordinates

1. Search SISAL using sisal_search_caves MCP tool
2. Get cave metadata: entity_id, coordinates, site name
3. Determine data coverage: earliest/latest sample dates

# Example MCP call
sisal_search_caves region="California" min_samples=50

Step 2: Search for Modern Earthquakes

Use earthquake_search MCP tool to find earthquakes near cave:

# Default: M≥5.0, 100 km radius, 1900-2025
earthquake_search lat=36.59 lon=-118.82 min_magnitude=5.0 radius_km=100

Filter results:

• Keep only earthquakes within cave data timespan
• Note earthquakes outside timespan (for documentation)

Step 3: Download Cave Data

Use sisal_get_samples MCP tool:

sisal_get_samples entity_id="123"

Extract:

• δ18O measurements with dates
• δ13C measurements (if available)
• Mg/Ca measurements (if available)

Step 4: Calculate Baseline Statistics

For all cave data:

δ18O: μ = mean(d18O_measurement), σ = std(d18O_measurement)
δ13C: μ = mean(d13C_measurement), σ = std(d13C_measurement)

Step 5: Test Each Earthquake

For each earthquake within cave data coverage:

1. Define test window: earthquake_year ± 10 years
2. Extract data in window: All samples within ±10 years
3. Calculate z-scores: z = (measurement - μ) / σ
4. Find extreme values: Most negative AND most positive z-score
5. Apply detection threshold:
   • |z| ≥ 2.0 → DETECTED
   • |z| < 2.0 → NOT DETECTED

Step 6: Generate Results Table

| Date | Magnitude | Distance (km) | Cave Data? | δ18O z | Detection | Notes |
|------|-----------|---------------|------------|--------|-----------|-------|
| 1976-02-04 | M7.5 | 30 km | ✓ Yes | +1.32σ | ✗ NO | Below threshold |
| 1896-07-21 | M6.3 | 48 km | ✓ Yes | -3.54σ | **✓ YES** | Strong signal |

Step 7: Calculate Statistics

Detection rate = (detections / tests_with_data) × 100%

Example:
- Total earthquakes found: 9
- Earthquakes with cave coverage: 6
- Detections (z ≥ 2.0): 1
- Non-detections: 5
- **Detection rate: 16.7%**

Step 8: Update VALIDATION_MATRIX_50PLUS.md

Add/update cave section in paleoseismic_caves/VALIDATION_MATRIX_50PLUS.md:

### [Cave Name] ([Country]) - [N] Earthquakes

**Cave coordinates**: [lat]°N, [lon]°W
**Data coverage**: [start] - [end] CE
**Cave entity**: [entity_id] (SISAL)

#### Modern Earthquakes:

[Results table]

**Detection rate**: X/Y (Z%)

**Notes**: [Interpretation, hypotheses for non-detections]

Detection Criteria

Threshold	Interpretation
z ≥ +2.0 or z ≤ -2.0	DETECTED (significant anomaly)
1.5 ≤	z
	z

Interpreting Results

High Detection Rate (≥60%)

• Cave is sensitive to earthquakes
• Methodology validated for this setting
• Prehistoric detections are credible

Moderate Detection Rate (30-60%)

• Cave may be selective (certain magnitudes/distances)
• Need to identify detection threshold
• Prehistoric detections need scrutiny

Low Detection Rate (<30%)

• Cave may be insensitive after certain date
• Check for cave changes (flowpath, aquifer)
• Prehistoric detections HIGHLY UNCERTAIN

Zero Detection (0%)

• Critical concern (like Yok Balum)
• Investigate: (a) Cave sensitivity, (b) Tectonic setting, (c) Data quality
• Prehistoric "detections" may not be seismic

Output Format

The skill outputs:

1. Cave metadata box (coordinates, coverage, entity_id)
2. Earthquake search summary (N earthquakes found, N testable)
3. Full results table (all earthquakes with test results)
4. Statistics summary (detection rate, range tested)
5. Interpretation (what results mean for methodology)
6. Update to VALIDATION_MATRIX_50PLUS.md (with approval)

MCP Tools Used

Tool	Purpose
sisal_search_caves	Find cave in SISAL database
sisal_get_samples	Download δ18O/δ13C/Mg measurements
earthquake_search	Search USGS catalog near cave
calc_distance	Verify earthquake-cave distances
calc_pga	Calculate expected ground acceleration

Example Full Workflow

User: /validate-cave CRC-3

Claude:
1. Searching SISAL for CRC-3 (Crystal Cave)...
   - Entity ID: 123
   - Coordinates: 36.59°N, 118.82°W
   - Data: 873-2006 CE (1,054 δ18O measurements)

2. Searching USGS catalog (M≥5.0, 100km, 1900-2025)...
   - Found 11 earthquakes
   - 9 within cave data coverage (873-2006 CE)

3. Calculating z-scores...
   - Baseline: μ=-8.23‰, σ=0.42‰

4. Testing each earthquake...
   [Results table]

5. RESULTS:
   - Detections: 9/9
   - Detection rate: **100%** ✓✓✓

6. INTERPRETATION:
   Crystal Cave shows PERFECT detection of modern earthquakes.
   This validates the methodology for California Sierra Nevada setting.

Would you like me to update VALIDATION_MATRIX_50PLUS.md with these results?

Important Notes

1. Document BOTH detections AND non-detections - Publication requires honest statistics
2. Non-detection ≠ failure - May indicate distance/magnitude thresholds
3. 0% detection is significant - Yok Balum 0% rate is scientifically valuable
4. Check data quality - Missing samples around earthquake = inconclusive, not non-detection
5. Consider tectonic setting - Strike-slip vs thrust vs subduction may behave differently