Water Review 8th grade EOG

Properties of water Polarity: Water has a positively charged end and negatively charged end o Cohesion: Water’s ability to stick to itself (water forming droplets) o Adhesion: water’s ability to stick to other objects (water sticking to a leaf) o High surface tension: water sticks to itself on the surface of a body of water (surface of a pond or pool) o Density: water’s density is 1 o High specific heat: it takes a long time for water to heat up, numerical specific heat is 1 Universal Solvent: water dissolves many substances- this is also why water is rarely pure.

Water distribution Water Distribution - Water is the only substance on Earth that exists as a _solid__, __liquid__, and a gas. - Water covers approximately ______71_____% of the Earth’s surface (USGS). - Most of this water (97%) is not drinkable because it is ___salty___________. - The majority of freshwater (___3___%) exists in ice caps and ____glaciers____- 77% of the freshwater is ___frozen______. - Of the 23% that is not frozen, approximately a half of a percent is available to supply living organisms with what they need to survive

Ocean Saltiness Ocean Saltiness: (ocean salinity is ___35____ppt) - Oceans are salty because: chemicals on the Earth's crust erode and wash into the sea. Hydrothermal vents also release dissolved minerals - Salinity increases when: there is evaporation or freezing into ice (salt can’t be frozen into ice) - Salinity decreases when: there is rainfall, ice melting, or runoff The ocean is an integral component of the world's climate due to its capacity to collect, drive and mix water, __heat____, and _____carbon dioxide______.

Hydrologic cycle

River Basins River Basins: A ___river basin___________ is the portion of land drained by a river and its ____tributaries___________. It encompasses the entire land surface drained by the various streams and creeks that flow downhill into one another, and eventually into one ______main river_________. The final destination of the water drained by a river basin is an estuary or an _____ocean___________. A river basin sends all the water falling on the surrounding land into a central river and out to the sea. For land-dwellers, _____everybody________ lives in a river basin even if they do not live near the water. There are ____17____ river basins in North Carolina.

Ocean Resources OCEAN RESOURCES The ____OCEAN_____ is a dynamic system in which many chemical, biological, and physical changes are taking place. The ocean is an important source of ____FOOD_____ and mineral resources as well as a venue for human recreation and transportation. The ocean is the single largest reservoir of __HEAT______at Earth’s surface. The stored heat in the ocean drives much of Earth’s weather and causes climate near the ocean to be milder than climate in the interior of continents.

DISSOLVED GASES Seawater has many different gases dissolved in it, especially nitrogen, _____OXYGEN_____ and ___CARBON DIOXIDE__. Cold water holds _____MORE____ gas than warm water. Seawater with low salinity holds ____MORE____ gas than high salinity water. Deep water, which has a high pressure, holds ___MORE_____ gas than shallow water.

ESTUARIES Estuaries are areas where __SALTY__ and __FRESH____ water mix, producing variations in salinity and high biological activity Because estuarine waters are ______SHALLOW______ (in North Carolina, less than thirty feet deep), sunlight penetrates to the bottom. This promotes ______PLANT__ growth. The rivers that feed estuaries deposit sediments rich in nutrients, which settle onto the sand and mud of the estuary floor. These conditions create unique habitats for both plants and animals, and provide the basis for great biological diversity in species (of fish, shrimp, crabs, clams and oysters) that are able to adapt to the brackish conditions. Estuaries are also good ___NURSURIES_____as they provide a protected environment for species to hatch and grow in before they migrate to the sea to live out their adult lives. Estuaries are a type of environmental ___FILTER__________. The largest North Carolina estuary is _________PAMLICO SOUND____________

OCEAN LIFE Most ocean food chains begin with ___PHYTOPLANKTON______, which are ___ALGAE___ that ___PHOTOSYNTHESIZE___. They can only be found in the ____PHOTIC____ zone of the ocean where light is able to reach. Intertidal Zone: BETWEEN HIGH AND LOW TIDE. ANIMALS HERE MUST PUT UP WITH DRASTIC DIFFERENCES IN SALINITY, WATER DEPTH, AND TURBIDITY. Hydrothermal Vent: CREATURES MUST ENDURE EXTREME PRESSURE, TEMPERATURES, NO LIGHT, AND TOXIC CHEMICALS- FOOD WEB BEGINS WITH BACTERIA (CHEMOSYNTHETIC)

UPWELLING Upwelling happens when WARM____ surface water near coastal areas is blown offshore by winds. This creates a condition in which the cold water along the bottom of the ocean near the shore ____RISES___, carrying sediment and organic material to the surface. ____ORGANISMS______uses these nutrients to grow and reproduce at a rapid rate.

List all the ways you can think of that the oceans help people and the Earth? REMOVES CARBON AND PROVIDES OXYGEN (PHOTOSYNTHESIS) FISHING/ FOOD AND INDUSTRY SHIPPING CARGO TOURISM MINING FOR DIAMONDS, METALS, NODULES DRILLING FOR OIL SCIENTIFIC STUDY

WATER SYSTEM HEALTH The health of a water system is determined by the balance between physical, chemical and biological variables. Physical variables include _____TEMPERATURE______, ______TURBIDITY____, and water movement. Chemical variables include dissolved ____OXYGEN_____ and other gases, pH, ______NITRATES_____, and salinity. Both natural and man-made forces are constantly changing these variables.

How do each of the following indicators affect water? Temperature: DETERMINES WHAT CAN LIVE THERE, THE WARMER THE WATER THE LESS DISSOLVED OXYGEN. Dissolved oxygen: ANIMALS NEED IT TO LIVE. CAN CHANGE WITH SEASON AND WITHIN THE DAY pH: IF A pH IS TOO HIGH, TOXINS ARE MORE LIKELY TO BE PRODUCED. Nitrogen/phosphates: NECESSARY FOR PLANTS, BUT TOO MUCH WILL CAUSE ALGAL BLOOMS AND LEAD TO EUTROPHICATION Turbidity: (measured with a ______SECCI DISK_____________) A MEASURE OF HOW CLEAR THE WATER IS. TOO MUCH TURBIDITY WILL LEAD TO INCREASED TEMPERATURES AND LOWER DISSOLVED OXYGEN Bioindicators: BIOINDICATORS ARE SENSITIVE CREATURES THAT CAN ONLY LIVE IN CERTAIN CONDITIONS. IF THEY ARE THERE, THEN THE WATER IS HEALTHY, IF THEY ARE NOT THERE, THEN THE WATER IS NOT HEALTHY. MACROINVERTEBRATES ARE USUALLY USED AS BIOINDICATORS.

POINT SOURCE POLLUTION In point source pollution, you can literally point to the source, it is some place that can be identified. ex) factory releasing hot water or chemicals into a stream ex) damaged pipes leaking ex) release of dishwater or sewage from homes into a water system

NONPOINT SOURCE POLLUTION Non-point sources pollution is pollution that comes from many places or is from an unidentified source. ex) runoff from fields or feedlots ex) soil from farms ex) runoff from city streets ex) fertilizers, salts, irrigation from farm fields ex) acid rain

Pollution practice ___PS__ leaky or damaged sewer pipes ___NP__ waste runoff from farm fields ___NP___ acid rain ____NP___ sand, grit, oil, and gasoline run off from city streets ____PS_releasing chemicals from factories ___PS__ heated water from power plants released to streams ___PS__ dishwater/sewage from homes to streams __NP_ soil from farms.

Drinking water Clear water may contain odorless, tasteless, and colorless harmful ______CONTAMINANTS________. Natural supplies of ___POTABLE/DRINKABLE_____ water are very limited and do not exist in sufficient quantities to meet human needs.

MONITORING WATER SONAR: measures depth by bouncing sound wave from the ocean floor Satellites: can monitor storms like hurricanes or can monitor large ocean algal blooms.