Moraine Position Recession Rate Calculator
Infer signed mean historical recession between dated moraine positions with outward-distance convention and decreasing ages-before-present; assumes moraines represent termini, not dating certainty or modern feature motion.
Description
Dated moraine positions can support an interval-average historical recession estimate.
Dated moraine positions can support an interval-average historical recession estimate. Ages before present decrease toward the younger marker.1
Enter nonnegative ages with older>younger and finite signed distances on one outward-distance convention. Return signed meters and m/year.
When to use Moraine Position Recession Rate Calculator
Use Moraine Position Recession Rate Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. The model assumes markers represent termini; dating uncertainty and present feature motion are excluded.
Prepare the observed ice, snow, water or geometry measurements and explicit calibration parameters requested. Keep coordinates, datum, density and time units consistent.
How to use Moraine Position Recession Rate Calculator and understand its results
- Prepare the observed ice, snow, water or geometry measurements and explicit calibration parameters requested. Keep coordinates, datum, density and time units consistent.
- Enter olderMoraineAgeYearsBeforePresent, youngerMoraineAgeYearsBeforePresent, olderDistanceFromReferenceM, youngerDistanceFromReferenceM using the field table and calculation rules, then run the tool.
- Read signedMoraineInferredRecessionM, meanInferredRecessionMYear. 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 |
|---|---|---|---|
| olderMoraineAgeYearsBeforePresent | Older moraine age years before present | number | Required |
| youngerMoraineAgeYearsBeforePresent | Younger moraine age years before present | number | Required |
| olderDistanceFromReferenceM | Older distance from reference m | number | Required |
| youngerDistanceFromReferenceM | Younger distance from reference m | number | Required |
Enter nonnegative ages with older>younger and finite signed distances on one outward-distance convention. Return signed meters and m/year.
recession=olderOutwardDistance−youngerDistance; rate=recession/(olderAge−youngerAge) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| signedMoraineInferredRecessionM | Signed moraine inferred recession m | number |
| meanInferredRecessionMYear | Mean inferred recession m year | number |
{
"input": {
"olderMoraineAgeYearsBeforePresent": 100,
"youngerMoraineAgeYearsBeforePresent": 50,
"olderDistanceFromReferenceM": 1000,
"youngerDistanceFromReferenceM": 500
},
"output": {
"signedMoraineInferredRecessionM": 500,
"meanInferredRecessionMYear": 10
}
}Limitations and assumptions
The model assumes markers represent termini; dating uncertainty and present feature motion are excluded.
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 Snout Recession Length Per Decade Calculator: An observed decade recession uses positions at both ends of a complete ten-year window. Short-term rates are not rescaled beyond coverage. For a complementary task, use Surge Front Advance Rate Calculator: A surge-activation front is a tracked threshold location. Its motion differs from the velocity of individual ice particles.
References
Similar or alternative tools
- Snout Recession Length Per Decade Calculator
An observed decade recession uses positions at both ends of a complete ten-year window. Short-term rates are not rescaled beyond coverage.
- Surge Front Advance Rate Calculator
A surge-activation front is a tracked threshold location. Its motion differs from the velocity of individual ice particles.