Subglacial Water Pressure Ratio Calculator
Audit observed pressure fractions of ice overburden without clamping superflotation evidence; distinct from signed effective-pressure subtraction and not hydraulic contact stability.
Description
Ice overburden provides a reference pressure for subglacial water.
Ice overburden provides a reference pressure for subglacial water. Ratios above one should remain visible as superflotation evidence.1
Enter aligned nonempty nonnegative pressures/positive thicknesses and positive density/gravity. Return ratios and strict-above-one indices.
When to use Subglacial Water Pressure Ratio Calculator
Use Subglacial Water Pressure Ratio Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. No clamping, contact stability or effective-pressure subtraction is performed.
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 Subglacial Water Pressure Ratio 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 observedWaterPressuresPa, iceThicknessesM, iceDensityKgM3, gravityMSecond2 using the field table and calculation rules, then run the tool.
- Read waterToOverburdenPressureRatios, aboveOverburdenObservationIndices. 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 |
|---|---|---|---|
| observedWaterPressuresPa | Observed water pressures Pa | list of number | Required |
| iceThicknessesM | Ice thicknesses m | list of number | Required |
| iceDensityKgM3 | Ice density kg m3 | number | Required |
| gravityMSecond2 | Gravity m second2 | number | Required |
Enter aligned nonempty nonnegative pressures/positive thicknesses and positive density/gravity. Return ratios and strict-above-one indices.
ratio=waterPressure/(iceDensity×gravity×thickness) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| waterToOverburdenPressureRatios | Water to overburden pressure ratios | list of number |
| aboveOverburdenObservationIndices | Above overburden observation indices | list of number |
{
"input": {
"observedWaterPressuresPa": [
0,
2000
],
"iceThicknessesM": [
1,
1
],
"iceDensityKgM3": 1000,
"gravityMSecond2": 1
},
"output": {
"waterToOverburdenPressureRatios": [
0,
2
],
"aboveOverburdenObservationIndices": [
1
]
}
}Limitations and assumptions
No clamping, contact stability or effective-pressure subtraction is performed.
Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 10,000 entries; string lists to 128 strings of at most 128 characters each. The rules above may impose smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Flotation Fraction Buoyancy Calculator: Buoyant support depends on submerged draft relative to total thickness and the two densities. The ratio can exceed total ice weight. For a complementary task, use Calving Front Cliff Height Above Water Calculator: Calving-cliff height can be measured relative to both water level and toe. A submerged top remains a signed observation.
References
Similar or alternative tools
- Flotation Fraction Buoyancy Calculator
Buoyant support depends on submerged draft relative to total thickness and the two densities. The ratio can exceed total ice weight.
- Calving Front Cliff Height Above Water Calculator
Calving-cliff height can be measured relative to both water level and toe. A submerged top remains a signed observation.