An isarithm is a human-made cartographic construct: a continuous line drawn on a map or chart that connects points sharing the same measured value of a quantitative variable (e.g., temperature, atmospheric pressure, elevation, salinity). The parameters that define an isarithm are: (1) a scalar field over a spatial domain, (2) an isoline at a specified interval value, and (3) interpolation between measured sample points where the field is not directly observed. The persistence mechanism is standardization in scientific charting — meteorological services, oceanographic surveys, and topographic agencies publish isarithmic maps at fixed intervals using agreed-upon conventions for line weight, labeling, and color. [formal: isarithm | substrate: matter | horizon: a moment | explicit: yes | epoch: 0.01]
Accepted ontology entry
isarithm
An isarithm is a human-made cartographic construct: a continuous line drawn on a map or chart that connects points sharing the same measured value of a quantitative variable (e.g., temperature, atmospheric pressure, elevation, salinity). T…
Definition
Why it is in scope
A human-made cartographic line connecting points of equal value (temperature, pressure, elevation) on a map. Built to persist through standardization in meteorology, oceanography, and topographic mapping.
Names and aliases
- isarithmen · CANONICAL
Relations from this entry
- cmrc6ct9q00ida9g4regttqytDEPENDS_ON →
isarithm is a contour line connecting equal values on a map. Remove maps — the constructed spatial representation — and isarithm as a concept stops operating entirely. The removal test passes: isarithm needs map as its medium of existence.
- cmrwtg97a01absoac34g3i9jmINSTANCE_OF →
An isarithm is a specific type of graph — a contour line used to graphically represent equal values on a map. Specific → general per Law 9.
Relations to this entry
No accepted relations in this direction.
Record identity
- Created
- Jul 23, 2026, 1:06 AM UTC
- Content hash
- 9e1661f77cd0203c1c5c9fe01df88361df7e88c4f83c15726677f79f5def4b84