Water (Oceans)

Overview

Oceans cover 71% of Earth's surface. This chapter explores the topography of the hidden ocean floor, the factors governing seawater salinity, and the vertical/horizontal distribution of ocean temperature.

Learning Objectives

Describe the major and minor features of the ocean basin
Explain the spatial and vertical variations in ocean temperature
Identify the factors that control global ocean salinity
Analyze the role of oceans in global climate regulation

Key Concepts

Ocean Basin Relief

Includes the Continental Shelf, Slope, Rise, and the vast Abyssal Plains. Deep-sea trenches mark convergent plate boundaries.

Seawater Salinity

Influenced by evaporation, precipitation, river inflow, and ice melting. Average salinity is 35 parts per thousand (ppt).

Key Terms

IsohalineBathymetryRidgeMariana TrenchThermocline

Examples

The Dead Sea

Extremely high salinity (over 200 ppt) due to intense evaporation and being a landlocked basin.

Quick Check

What is the average salinity of the ocean?
What is a 'Guyot'?