4. Water Water is transparent, and aquatic plants can live within the water because sunlight can reach them. Only strong UV light is slightly absorbed.
5. Water All the major components in cells are dissolved in water
6. Water cycle The water cycle is caused by the sun, which heats water in the oceans and causes evaporation
7. Water cycle In the sky the water vapor packs together and forms clouds known as condensation, than it falls back to the earth as precipitation
8. Water cycle A portion of runoff enters rivers in valleys in the landscape, with streamflow moving water towards the oceans. Runoff and groundwater are stored as freshwater in lakes. Not all runoff flows into rivers, much of it soaks into the ground as infiltration.
9. Water cycle Some infiltration stays close to the land surface and can seep back into surface-water bodies (and the ocean) as groundwater discharge. Some groundwater finds openings in the land surface and comes out as freshwater springs.
10. Ocean Topography The ocean surface has highs and lows, similar to the hills and valleys of Earth's land surface depicted on a topographic map. These variations, called "ocean surface topography" or "dynamic sea surface topography" are mapped using measurements of sea surface height relative to Earth's geoids.
11. Ocean Topography Ocean surface topography is used to map ocean currents, which move around the ocean's "hills" and "valleys" in predictable ways.
12. Ocean Topography Ocean surface topography is also used to understand how the ocean moves heat around the globe, a critical component of Earth's climate, and for monitoring changes in global sea level.
13. Ocean Topography The height variations of ocean surface topography can be as much as two meters and are influenced by ocean circulation, ocean temperature, and salinity
14. Currents and Tides Tides are the rise and fall of sea levels caused by the combined effects of the rotation of the Earth and the gravitational forces exerted by the Moon and the Sun
15. Currents and Tides High and low tides Most coastal areas experience two daily high (and two low) tides. (High tide)
16. Currents and Tides Wave structure Wind blows across the water making a big wave.
17. Currents and Tides Tsunami strikes. Underwater Earthquakes causes waves to get big and cause
18. How Do Humans effect the water The ocean absorbs a great amount of carbon dioxide and pollutants, but pollution levels of our whole Earth system are reaching beyond carrying capacity. As human population has increased, so has the deterioration of the world's ocean ecosystems.
19. How Do Humans effect the water Two thirds of the major cities in the world are situated along coasts, and millions of people vacation at shorelines. Pollution from developed areas drains into the ocean killing marine life, threatens human health, causes toxic algae blooms, and forces beach closures. Human pollution is destroying coral reefs and coastal habitat which are vital for breeding, food and shelter for marine species.
