Page 620 - 9780077418427.pdf

/Volume/201/MHDQ233/tat78194_disk1of1/0073378194/tat78194_pagefiles
tiL12214_ch24_597-622.indd Page 597 9/23/10 11:08 AM user-f465
tiL12214_ch24_597-622.indd Page 597 9/23/10 11:08 AM user-f465 /Volume/201/MHDQ233/tat78194_disk1of1/0073378194/tat78194_pagefile

24 Earth’s

24 Waters

Vast oceans cover more than 70 percent of the surface of Earth. Freshwater
is generally abundant on the land because the supply is replenished from
ocean waters through the hydrologic cycle.

CORE CONCEPT

The hydrologic cycle is evaporation of water from the ocean, transport by moving
air masses, precipitation on the land, and movement of water back to the ocean.

OUTLINE

24.1 Water on Earth
Water on Earth Freshwater Freshwater
Most water on Earth is stored in Science and Society: Water Quality Precipitation flows across the
its oceans. Surface Water surface in streams and rivers or
Groundwater soaks in to become groundwater.
Freshwater as a Resource
A Closer Look: Water Quality
Freshwater as a Resource and Wastewater Treatment
About two-thirds of municipal 24.2 Seawater Seawater
water supplies come from Oceans and Seas More than 70 percent of Earth is
surface water and one-third from The Nature of Seawater covered by seawater.
Movement of Seawater
groundwater.
A Closer Look: Estuary Pollution
Waves
A Closer Look: Health of the
Movement of Seawater Chesapeake Bay
The ocean is well mixed by A Closer Look: Rogue Waves
waves and currents. Ocean Currents
People Behind the Science:
Rachel Louise Carson
24.3 The Ocean Floor

597