verify-dark
Verify dark earthquake claims against fault databases. Use when checking if a candidate earthquake is truly "dark" (unmapped fault) or just pre-historical (known fault). Triggers on "verify dark", "check fault database", "is this dark", "audit earthquake claim".
When & Why to Use This Skill
The verify-dark skill is a specialized tool for seismologists and geological researchers to audit 'dark earthquake' claims. It automates the complex process of cross-referencing seismic event coordinates against multiple global and regional fault databases—such as DISS, SCEC, and GEM—while synthesizing recent academic literature to determine if an earthquake originated from an unmapped fault or a known pre-historical source.
Use Cases
- Seismological Auditing: Automatically verify whether a historical earthquake record is 'dark' (unmapped fault) or 'pre-historical' (known fault) to maintain accurate and scientifically rigorous seismic catalogs.
- Geological Data Integration: Streamline the search across disparate regional databases like Italy's DISS, California's SCEC, and the GEM Global Active Faults database to identify seismogenic sources near specific coordinates.
- Paleoseismic Research: Support the classification of seismic events in regions with incomplete mapping, such as stable continental interiors or pre-instrumental historical periods, by combining database queries with DEM lineament analysis.
| name | verify-dark |
|---|---|
| description | Verify dark earthquake claims against fault databases. Use when checking if a candidate earthquake is truly "dark" (unmapped fault) or just pre-historical (known fault). Triggers on "verify dark", "check fault database", "is this dark", "audit earthquake claim". |
/verify-dark - Fault Database Verification Skill
Purpose
Verify if a candidate "dark earthquake" claim is truly dark (unmapped source fault) or pre-historical (known fault, no written record). This skill automates the DARK_EARTHQUAKE_AUDIT.md workflow.
Usage
/verify-dark <lat> <lon> <date_CE> [region]
Examples:
/verify-dark 44.2 8.1 1394 italy
/verify-dark 32.7 -117.2 1741 california
/verify-dark -16.5 -44.8 96 brazil
/verify-dark 22.4 -84.0 1400 caribbean
Workflow
Step 1: Identify Region & Databases
Based on coordinates, determine which fault databases to check:
| Region | Primary Database | Secondary Databases |
|---|---|---|
| Italy | DISS v3.3.1 (INGV) | ITHACA, EFSM20, GEM SHARE |
| California | SCEC CFM v7.0 | CGS FER, USGS Quaternary |
| Caribbean/C. America | GEM CCAF-DB | USGS |
| Brazil | GEM SARA | (Note: Brazil EXCLUDED from SARA) |
| Middle East | EMME | GEM, Hessami (2003) |
| Romania | RODASEF | ESHM20, SHARE |
| Turkey | AFAD | GEM, Emre et al. |
Step 2: Search Fault Databases
For each database, search within 50km and 100km radius:
- Use calc_distance MCP tool to compute distances from candidate to known faults
- Query database (WFS endpoint if available, or web search for geojson)
- Record all faults found with strike, slip type, distance
Example search pattern:
# Check DISS v3.3.1 for Italy
WebFetch: https://diss.ingv.it/diss330/download/DISS330_ISS.geojson
Filter: features within 100km of (lat, lon)
# Check SCEC CFM for California
WebFetch: https://www.scec.org/research/cfm
Search for fault traces near coordinates
Step 3: Check Recent Literature (2010+)
Search for recent fault mapping publications:
- WebSearch: "[region] fault mapping [year range]"
- WebSearch: "paleoseismic trench [fault name]"
- WebSearch: "[coordinates] seismogenic source"
Look for:
- New fault discoveries
- Offshore/submarine fault extensions
- DEM-based lineament studies
- Paleoseismic trenching results
Step 4: Run DEM Lineament Check (if available)
If DEM data exists for the region:
- Check
dem_tiles/for existing analysis - Reference
DEM_LINEAMENT_FINDINGS.mdor similar - Note any unmapped structures identified
Step 5: Generate Verification Table
Create markdown table summarizing findings:
| Database | Checked | Faults within 50km | Faults within 100km | Notes |
|----------|---------|-------------------|---------------------|-------|
| DISS v3.3.1 | ✅ | [fault names] | [fault names] | [details] |
| ITHACA | ✅ | ... | ... | ... |
| EFSM20 | ✅ | ... | ... | ... |
| GEM | ✅ | ... | ... | ... |
| Recent lit | ✅ | ... | ... | [citations] |
Step 6: Classify Event
Based on findings, classify as:
| Classification | Criteria |
|---|---|
| TRUE DARK | No mapped fault in ANY database (like Italy 1394, Brazil events) |
| PRE-HISTORICAL | Known fault exists, but earthquake predates written records (like California 1741) |
| PRE-COLUMBIAN | Event in Americas before 1492 (no records possible) |
| PRE-INSTRUMENTAL | Event before seismometer network (varies by region) |
| VALIDATION | Known earthquake used to test methodology (like Cuba 1766) |
| DATABASE ARTIFACT | "Missing" due to incomplete database, fault IS mapped elsewhere |
Step 7: Update DARK_EARTHQUAKE_AUDIT.md
Add new section to paleoseismic_caves/DARK_EARTHQUAKE_AUDIT.md:
### ✅ [Region]: [Date] - **[CLASSIFICATION]**
**Date verified**: [today's date]
**Classification**: **[CLASSIFICATION]** ([explanation])
**Databases checked**:
- ✅ **[Database 1]** - [findings]
- ✅ **[Database 2]** - [findings]
...
**Key findings**:
[Summary of what was found]
**Conclusion**: [Why this classification]
**Likelihood of database artifact**: **[HIGH/LOW/ZERO]** - [explanation]
Classification Decision Tree
Is there a mapped fault within 100km in ANY database?
├─ YES → Is earthquake in historical catalogs?
│ ├─ YES → VALIDATION EVENT
│ └─ NO → PRE-HISTORICAL (known fault, no record)
│ └─ If Americas pre-1492 → PRE-COLUMBIAN
│ └─ If pre-seismometer → PRE-INSTRUMENTAL
└─ NO → Does a fault database exist for this region?
├─ NO (e.g., Brazil) → TRUE DARK (no database = genuine gap)
└─ YES → Did DEM analysis find unmapped structure?
├─ YES → TRUE DARK (candidate)
└─ NO → UNATTRIBUTED (needs more research)
Output Format
The skill will output:
- Summary box at top with classification
- Verification table with all databases checked
- Key findings with quotes/evidence
- Classification rationale explaining decision
- Update to DARK_EARTHQUAKE_AUDIT.md (with approval)
Database URLs Reference
Italy:
- DISS v3.3.1: https://diss.ingv.it/
- ITHACA: http://ithaca.rm.ingv.it/
- EFSM20: https://seismofaults.eu/
California:
- SCEC CFM: https://www.scec.org/research/cfm
- CGS FER: https://maps.conservation.ca.gov/cgs/fer/
Caribbean:
- GEM CCAF-DB: https://github.com/GEMScienceTools/CCAF-DB
Middle East:
Global:
- GEM Global Active Faults: https://github.com/GEMScienceTools/gem-global-active-faults
Important Notes
- USGS Quaternary Fault Database has 9-27 year lag - never use as sole source
- Brazil is excluded from GEM SARA - stable continental interiors have no fault databases
- "Dark" means UNMAPPED FAULT, not just "no written record"
- Always check 3+ databases before classifying as TRUE DARK
- DEM lineament analysis strengthens case for unmapped structures