Isohalines are lines joining equal:
salinity.
Understanding Isohalines: Lines of Equal Salinity
In geography and oceanography, maps often use lines to connect points that have the same value of a particular property. These lines are generally called isolines.
The question asks about a specific type of isoline: isohalines. To answer this, we need to understand what 'isohaline' means.
What are Isohalines?
The term 'isohaline' comes from 'iso' meaning equal, and 'haline' referring to salt. Therefore, isohalines are lines that connect points of equal salinity in a body of water, such as oceans, seas, or lakes.
Salinity refers to the concentration of salt in water. Mapping salinity levels using isohalines helps scientists and geographers visualize the distribution of saltiness across a region.
Analyzing the Options
Let's look at the provided options and see which one corresponds to the definition of isohalines:
- Option 1: temperature. Lines joining equal temperature are called isotherms.
- Option 2: pressure. Lines joining equal pressure (especially atmospheric pressure) are called isobars.
- Option 3: rainfall. Lines joining equal rainfall (or precipitation) are called isohyets.
- Option 4: salinity. Lines joining equal salinity are called isohalines.
Based on the definition, isohalines are lines joining equal salinity.
Why Salinity is the Correct Answer
As defined above, the specific term 'isohaline' is used to represent lines that connect locations with the same measurement of salinity. This is a standard term used in mapping and scientific diagrams related to water bodies.
Understanding different types of isolines is important in interpreting geographical and meteorological maps.
Revision Table: Common Isolines
| Isoline Type | Connects Points of Equal... |
|---|---|
| Isotherm | Temperature |
| Isobar | Pressure |
| Isohyet | Rainfall/Precipitation |
| Isohaline | Salinity |
| Isobath | Depth of water body |
| Contour Line | Elevation (on land) |
Additional Information on Salinity
Salinity in oceans is typically measured in parts per thousand (ppt) or using the Practical Salinity Scale (PSS), which is dimensionless but roughly equivalent to ppt. The average ocean salinity is around 35 ppt.
Factors that affect the salinity of a body of water include:
- Evaporation: Increases salinity by removing fresh water.
- Precipitation: Decreases salinity by adding fresh water.
- River Inflow: Decreases salinity by adding fresh water.
- Melting Ice: Decreases salinity by adding fresh water.
- Freezing Ice: Increases salinity in the surrounding water as salt is excluded from the ice crystals.
Isohalines are used on maps to show how these factors influence the distribution of salt concentration in different areas.
Important Questions from Oceanography
Which one of the following is not a cold current?
The maximum depth of Lithosphere is found in the
The periodic rise and fall of ocean water in response to gravitational forces is called
Consider the following statements regarding 'fronts':
1. The movement of a front causes a slow change in weather in the area over which it moves.
2. Cold fronts are associated with thunderstorms.
3. Warm front is the boundary between an advancing mass of warm air where it is overriding and rising above a mass of colder air.
Which of the statements given above is/are correct?
Which of the following statements regarding neap tides is/are correct?
1. It occurs every 14-15 days, which coincides with the first and third quarter of the Moon.
2. This tide has a small tidal range because the gravitational forces of the Moon and the Sun are in quadrature.
Select the answer using the code given below:
