Structure of the Hydrosphere Monday, November 7, 2011

The Big Picture Around the continents... Oceans cover 2/3 of Earth’s surface! On land...Water flows in rivers and streams and fills lakes and ponds! Even underground... Water trickles through rock to create groundwater!

The Hydrosphere HYDROSPHERE= the part of Earth containing water most water in hydrosphere is liquid salt water = about 97% (oceans) fresh water = about 3% frozen: ice caps, glaciers, snow, permafrost liquid: groundwater, lakes, wetlands, rivers, atmosphere

Hydrosphere All Water Fresh Water

The Global Ocean Oceans cover ~71% of Earth’s surface All ocean water is connected in a global ocean divided by continents into four major parts: Pacific Ocean, Atlantic Ocean, Indian Ocean, Arctic Ocean

The Global Ocean

Ocean Size The Pacific Ocean is the largest and deepest covers 165 million square kilometers average depth of 4,282 meters deepest part = Marianas Trench region (about 11,033 meters deep!)

Ocean Size Other oceans are smaller: 2nd: Atlantic Ocean (half the volume of the Pacific!) 3rd: Indian Ocean Smallest: Arctic Ocean (much covered by sea ice)

Salinity Salinity = the concentration of salts in a liquid, such as water ocean water tastes salty because of dissolved salts ordinary table salt = about 85% of these salts in oceans! salinity increases as more salts are dissolved in water ocean water has a salinity of about 3.5% every 100g of ocean water contains average 3.5g of dissolved salts

Ocean Temperature temperatures vary depending on latitude and depth What parts of Earth receive the most sunlight and therefore more energy?

OceanTemperatures The EQUATOR receives more direct sunlight and therefore receives more energy from the sun Surface temps can reach 25°C Near the poles temperatures tend to be near freezing below a depth of 300m, water temperatures drop quickly as the sun no longer warms it In the deepest parts of the oceans, temps range from 1°C to 4°C

Freshwater Resources Most of Earth’s fresh water is frozen in polar ice caps covers almost all of Antarctica covers most of the Arctic Ocean, near the North Pole Glacier = a mass of ice and snow that moves slowly over Earth’s surface contain large amounts of frozen water

Fresh Water Groundwater = water located below Earth’s surface nearly 1/3 Earths fresh water forms when surface water moves down through soils and sediment to collect in spaces between underground rock particles aquifer = a rock layer that stores water and allows water to flow through it drinking water and irrigation water often come from aquifers

Groundwater

Wetlands and Land Water Most of Earth’s surface water is located in rivers, streams, lakes and wetlands wetlands = land areas that remain wet for all or part of the year act as sponges, collecting and holding rainwater to prevent flooding also filter pollutants and sediment out of water can improve the quality of water that will eventually become drinking water

Watersheds watershed = an area of land where precipitation collects and then drains into a single collection place, often a lake or an ocean sometimes called drainage basins, river basins main function = move water from higher to lower elevations

Other Surface Waters river = a large, flowing stream of water fed by other small streams tributaries = smaller streams that feed rivers lake = a low area of land where surface water run-off accumulates vary in size

Think About it... Why might groundwater be cleaner than surface water?