Isobath
Topic: Graphical Representation of Data and Thematic Maps · NCERT: Class 12, Ch 3 "Graphical Representation of Data"
Meaning
An isobath is an isopleth, a line joining places of equal value. It joins points of equal depth below the water surface in a sea, lake or river. Isobaths show the shape of the sea floor on charts, just as contours show height on land. Closely spaced isobaths mean a steep slope. Widely spaced ones mean a gentle slope. Sailors use them for safe navigation, and they show where the continental shelf (the shallow edge of a continent under the sea) ends.
Example
Off India's coasts, the isobaths are spaced more widely along the west coast, off Gujarat and Maharashtra, than along the east coast. This shows that the continental shelf is wider in the Arabian Sea than in the Bay of Bengal.
Don't confuse with
- A contour joins points of equal height above sea level on land. An isobath joins points of equal depth below water.
- An isohaline joins places of equal salinity, not equal depth.