Science / Geology / Hydrograph: A graph that shows the change of a water-related variable over time. Example: A stream discharge hydrograph shows the change in discharge of a stream over time.

International Hydrographic Organization

Science / Tides and Currents / International Hydrographic Organization: An institution consisting of representatives of a number of nations organized for the purpose of coordinating the hydrographic work of the participating governments. It had its origin in the Internati MORE


Science / Marine Biology / Hydrographic: Referring to the arrangement and movement of bodies of water, such as currents and water masses MORE

Hydrographic Datum

Science / Tides and Currents / Hydrographic Datum: A datum used for referencing depths of water and the heights of predicted tides or water level observations. Same as chart datum. See datum. MORE


Science / Tides and Currents / ZO: Symbol recommended by the International Hydrographic Organization to represent the elevation of mean sea level above chart datum. MORE

Beaufort Wind Scale

Science / Weather / Beaufort Wind Scale: A system of estimating and reporting wind speeds. It is based on the Beaufort Force or Number, which is composed of the wind speed, a descriptive term, and the visible effects upon land objects and/or MORE

Tidal Zoning

Science / Tides and Currents / Tidal Zoning: The practice of dividing hydrographic survey area into discrete zones or sections, each one possessing similar tidal characteristics. One set of tide reducers is assigned to each zone. Tide reducers a MORE