Sediment Focusing Factor Calculator
Compare complete core inventory with explicit independently justified atmospheric reference to apparent sediment focusing; not corrected Pb210 chronology or proof deposition difference is solely focusing.
Description
Core radionuclide inventory may differ from an independently justified atmospheric reference.
Core radionuclide inventory may differ from an independently justified atmospheric reference. Their ratio is an apparent focusing measure.1
Enter nonnegative complete core inventory and positive reference inventory on matched Bq/m² basis. Return ratio.
When to use Sediment Focusing Factor Calculator
Use Sediment Focusing Factor Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. No Pb-210 age correction or proof that focusing alone explains the discrepancy is supplied.
Prepare the observed lake or sample measurements and explicit calibration, reference values or thresholds requested. Keep depth coverage, units, dates and sampling conditions consistent.
How to use Sediment Focusing Factor Calculator and understand its results
- Prepare the observed lake or sample measurements and explicit calibration, reference values or thresholds requested. Keep depth coverage, units, dates and sampling conditions consistent.
- Enter observedCoreInventoryBqM2, callerExpectedAtmosphericInventoryBqM2 using the field table and calculation rules, then run the tool.
- Read apparentSedimentFocusingFactor. 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 |
|---|---|---|---|
| observedCoreInventoryBqM2 | Observed core inventory bq m2 | number | Required |
| callerExpectedAtmosphericInventoryBqM2 | Caller expected atmospheric inventory bq m2 | number | Required |
Enter nonnegative complete core inventory and positive reference inventory on matched Bq/m² basis. Return ratio.
factor=coreInventory/expectedAtmosphericInventory Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| apparentSedimentFocusingFactor | Apparent sediment focusing factor | number |
{
"input": {
"observedCoreInventoryBqM2": 200,
"callerExpectedAtmosphericInventoryBqM2": 100
},
"output": {
"apparentSedimentFocusingFactor": 2
}
}Limitations and assumptions
No Pb-210 age correction or proof that focusing alone explains the discrepancy is supplied.
Numeric inputs, where present, 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.
Alternative or Complementary methods
Use Cesium 137 Peak Year Marker Lookup: A measured Cs-137 peak can mark a core depth only when it is uniquely resolved. The calendar assignment needs independent justification. For a complementary task, use Sediment Accumulation Rate MM Year Calculator: Two independently dated sediment markers define an interval-average thickness accumulation rate. This does not establish a continuous deposition history.
References
-
Sediment Focusing Factor Calculator — tool.io
Similar or alternative tools
- Cesium 137 Peak Year Marker Lookup
A measured Cs-137 peak can mark a core depth only when it is uniquely resolved. The calendar assignment needs independent justification.
- Sediment Accumulation Rate MM Year Calculator
Two independently dated sediment markers define an interval-average thickness accumulation rate. This does not establish a continuous deposition history.