Historical Eruption Frequency Per Century Calculator
Historical qualified catalog event/exposure rate, unqualified windows reported not silently pooled, no Poisson recurrence probability or next eruption prediction. Caller independently establishes units, regime, calibration and applicability; this does not establish design-code compliance, authenticity, operational safety, treatment efficacy or a validated forecast.
Description
Historical eruption frequency needs both counted events and an observation period judged sufficiently complete.
Historical eruption frequency needs both counted events and an observation period judged sufficiently complete.1
Pooling only qualified windows prevents incomplete catalog coverage from silently becoming a recurrence estimate.
When to use Historical Eruption Frequency Per Century Calculator
Use this tool when you need to reproduce the stated calculation from measured records or independently selected model inputs. Prepare matched observations and independently established site, specimen, units, datum, and calibration context.
How to use Historical Eruption Frequency Per Century Calculator and understand its results
- Prepare matched observations and independently established site, specimen, units, datum, and calibration context.
- Enter observedEruptionEventCounts, callerCompletenessVerifiedExposureYears, knownCatalogCompletenessFlags, following the field table and rules below, then run the tool.
- Read completenessQualifiedEruptionsPerCentury, unqualifiedCatalogExposureYears. Use the output meanings below to interpret units, signs, flags, and any nested result fields.
- Correct reported input issues and run again. For a successful result, check the stated evidence coverage and assumptions before using it in your review.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| observedEruptionEventCounts | Observed eruption event counts | list of number | Required |
| callerCompletenessVerifiedExposureYears | Caller completeness verified exposure years | list of number | Required |
| knownCatalogCompletenessFlags | Known catalog completeness flags | list of number | Required |
Use aligned nonempty nonnegative integer event counts, positive exposure years, and binary completeness flags. Require positive total qualified exposure. Divide qualified event totals by qualified years and scale to one century; separately sum unqualified exposure.
eventsPerCentury=100Σ(known_i×events_i)/Σ(known_i×years_i) Symbols follow the input and output meanings and the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| completenessQualifiedEruptionsPerCentury | Completeness qualified eruptions per century | number |
| unqualifiedCatalogExposureYears | Unqualified catalog exposure years | number |
{
"input": {
"observedEruptionEventCounts": [
2,
3
],
"callerCompletenessVerifiedExposureYears": [
10,
40
],
"knownCatalogCompletenessFlags": [
1,
0
]
},
"output": {
"completenessQualifiedEruptionsPerCentury": 20,
"unqualifiedCatalogExposureYears": 40
}
}Limitations and assumptions
Interpretation requires independently matched observations, units, site or specimen, and calibration. The calculation does not establish geological identity, operating safety, or an eruption forecast.
Missing required fields, unknown fields, wrong types, and violated calculation rules are input issues. Numeric values must be finite; nonfinite results are rejected. Evidence arrays must be dense, with no missing cells. Numeric observation lists allow at most 10,000 entries, subject to any smaller bounds stated above.
Alternative or Complementary methods
For a related review, use Volcanic Lightning Flash Count Proxy Tool: Volcanic lightning observations depend on how long a detector watched and what fraction of flashes it could detect. Correcting matched counts for detection coverage produces an observed flash rate, rather than an ash production estimate. For a complementary step, use Dormancy Reactivation Risk Score Calculator: An unrest score is a weighted summary of evidence under a chosen scoring policy. Missing evidence has its own weight, so the known-evidence score and coverage should be read together.
References
Similar or alternative tools
- Volcanic Lightning Flash Count Proxy Tool
Volcanic lightning observations depend on how long a detector watched and what fraction of flashes it could detect. Correcting matched counts for detection coverage produces an observed flash rate, rather than an ash production estimate.
- Dormancy Reactivation Risk Score Calculator
An unrest score is a weighted summary of evidence under a chosen scoring policy. Missing evidence has its own weight, so the known-evidence score and coverage should be read together.