 |
El Nino - The purpose of this Science NetLinks lesson is to understand that El Nino is caused by changes in the atmospheric and ocean content.
Oceans - The purpose of this lesson, from Science NetLinks, is to obtain a better perception of Earth's oceans and to understand Earth's water cycle.
Almost all our water is gathered in large, salty oceans that are pushed by the wind, pulled by the Moon, and swirled as the planet spins. Explore the mysteries of this hidden world and meet some of its endangered creatures through vivid footage and interviews with experts, including explorer Thor Heyerdahl.
Oceans cover three-quarters of Earth’s surface and are home to its largest variety of life. But there is much we still don’t know about the seas or the life they harbor. The crushing water pressure, extreme cold, and darkness of the ocean depths have prevented us from exploring 90 percent of the ocean floor. We know a bit more about the living marine cities of coral reefs—enough to know that they are endangered by many human activities such as dredging, filling, and pollution. We know that many types of fish are overexploited, and their numbers are in decline. The inner workings of ocean currents are more of a mystery. The accidental dumping of floating toys in the Pacific helped scientists trace currents as the toys floated to Alaska on an 11-year journey. The movements of mid and deep ocean currents affect everything
from water temperature and salinity to Earth’s weather patterns. Just as tides and waves shape the coastlines, currents reshape the ocean floor.
| |
