Oxygen Isotope Migration Proxy Tool
Apply caller enamel-to-water isotope calibration and compare a local baseline with independent uncertainty; differing isotope state is not proof of migration, birthplace or ancestry.
Description
Enamel oxygen isotopes can be compared with water baselines through an explicit calibration.
Enamel oxygen isotopes can be compared with water baselines through an explicit calibration. A standardized difference screens compatibility without turning isotope variation into proof of migration.1
Apply caller enamel-to-water isotope calibration and compare a local baseline with independent uncertainty; differing isotope state is not proof of migration, birthplace or ancestry.
When to use Oxygen Isotope Migration Proxy Tool
Use this tool to apply caller enamel-to-water isotope calibration and compare a local baseline with independent uncertainty; differing isotope state is not proof of migration, birthplace or ancestry.
Prepare the artifact, site or survey measurements and any independently established calibration or model choices. Keep paired observations aligned and confirm units and coordinate conventions.
How to use Oxygen Isotope Migration Proxy Tool and understand its results
- Prepare the artifact, site or survey measurements and any independently established calibration or model choices. Keep paired observations aligned and confirm units and coordinate conventions.
- Enter enamelDelta18O, waterConversionSlope, waterConversionIntercept, conversionResidualSigma, measurementSigma, localWaterMean, localWaterSigma, callerZThreshold using the field table and calculation rules, then run the tool.
- Read inferredWaterDelta18O, combinedComparisonSigma, signedLocalComparisonZ, aboveCallerDifferenceThreshold. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| enamelDelta18O | Enamel delta18 o | number | Required |
| waterConversionSlope | Water conversion slope | number | Required |
| waterConversionIntercept | Water conversion intercept | number | Required |
| conversionResidualSigma | Conversion residual sigma | number | Required |
| measurementSigma | Measurement sigma | number | Required |
| localWaterMean | Local water mean | number | Required |
| localWaterSigma | Local water sigma | number | Required |
| callerZThreshold | Caller z threshold | number | Required |
Supply finite isotope values and linear calibration coefficients, nonnegative measurement, conversion-residual and local-baseline sigmas, and a positive z threshold. Combine uncertainties as hypot(slope×measurementSigma,residualSigma,localSigma), requiring a positive total. Return inferred water value, sigma, signed z and a flag for absolute z strictly above the threshold.
waterValue = slope × enamelValue + intercept; z = (waterValue−localMean)/combinedSigma Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| inferredWaterDelta18O | Inferred water delta18 o | number |
| combinedComparisonSigma | Combined comparison sigma | number |
| signedLocalComparisonZ | Signed local comparison z | number |
| aboveCallerDifferenceThreshold | Above caller difference threshold | boolean |
{
"input": {
"enamelDelta18O": 10,
"waterConversionSlope": 0.5,
"waterConversionIntercept": -10,
"conversionResidualSigma": 1,
"measurementSigma": 2,
"localWaterMean": -6,
"localWaterSigma": 1,
"callerZThreshold": 2
},
"output": {
"inferredWaterDelta18O": -5,
"combinedComparisonSigma": 1.7320508075688772,
"signedLocalComparisonZ": 0.5773502691896258,
"aboveCallerDifferenceThreshold": false
}
}Limitations and assumptions
Independent uncertainties and the supplied isotope calibration are assumptions. Tissue formation, dietary effects and baseline coverage are not resolved. The flag does not establish birthplace, ancestry or migration.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.
Alternative or Complementary methods
Use Strontium Isotope Provenance Ratio Tool: Compare measured strontium ratio to all caller source baselines with independent sigma, retaining overlap and no matches; no ratio aliases, geographic identification or forced provenance. For a complementary task, use Isotopic Weaning Age Enamel: Locate a unique caller isotopic-enrichment transition on supplied enamel formation ages, excluding enamel maturation lag/other diet effects; proxy timing is not a confirmed age at cessation of breastfeeding.
References
-
Oxygen Isotope Migration Proxy Tool — tool.io
Similar or alternative tools
- Strontium Isotope Provenance Ratio Tool
Compare measured strontium ratio to all caller source baselines with independent sigma, retaining overlap and no matches; no ratio aliases, geographic identification or forced provenance.
- Isotopic Weaning Age Enamel
Locate a unique caller isotopic-enrichment transition on supplied enamel formation ages, excluding enamel maturation lag/other diet effects; proxy timing is not a confirmed age at cessation of breastfeeding.