Water Systems Review Assignment Answers How much of Earth’s supply of water is ocean water? • 97.2% How much of Earth’s supply of water is fresh water? • 2.8 % What is salinity? • The amount salt that is dissolved in the water Do all oceans have the same salinity? • No. It varies from one body of water to the next. Does Canada have a lot of fresh water? Explain • Yes because Canada has numerous rivers, glaciers, lakes, marshes, bogs and swamps. These are all sources of fresh water What are some examples of Fresh Water? • Rivers, glaciers, lakes, marshes, bogs and swamps. Draw a pie chart describing the distribution of water on Earth. Draw a labeled diagram of the Water Cycle. • See chart How does water cause erosion? • Water near the bank of a body of water moves some of the soil into the water. Over time, much of the soil on the bank gets moved and thus the shape of the Earth is changed. Floods are a major concern for people living where? • On floodplains (low lands where excess water can flow) What is the water table? • The water table is where water builds up under ground when it hits an impermeable layer of rock or clay. How does digging a well take advantage of the water table? • Because by digging a well, we can get access to underground water. Explain how the water cycle affects the water table. • During periods of drought, the water table goes down because the earth around it is dry. During periods of precipitation, it will rise. Explain why as rain begins to fall, it does not reach the saturated zone immediately. • Because it has to percolate through the soil first. This does not happen instanly. Why can people not swim in water that has a higher than normal amount of microorganisms? How can the amount of microorganisms in water increase drastically? • People could get sick or skin irritation from swimming in water that has a high content of microorganisms. • Microorganisms increase in water when too much pollution is present. Pollution is a breeding ground for bacteria. How do recreational activities cause pollution problems in waterways? • Boats leave gas and oil fumes in the water • Humans leave garbage or change the natural environment to build. What is acid precipitation? What are some of its effects? • Acid precipitation is when snow or rain pick up pollutants, from the air, as they fall to the ground. The result is that the precipitation turns into sulfuric or nitric acid • Some of the effects are: eats away at buildings, kills plants, disrupts ecosystems. Why should chemicals never be dumped down household or street drains? • The drain may have a direct route to a waterway What is the Mid-Ocean Ridge? • A chain of underwater mountains Describe how volcanic activity underwater is responsible for creating new islands. • When a volcano erupts, lava is release from the opening and then cooled by the surrounding water. Over time, this build up the volcano until it is higher than the water level. How can rivers shape the Earth’s surface? • Please see erosion question Why are glaciers called “Rivers of Ice”? • Glaciers are called rivers of ice because they are constantly moving. What is the difference between a polar ice cap and a glaciers? • Glaciers cover land and polar ice caps cover water. Explain how glaciers might be the answer to the world’s fresh water resource problems? • Since glaciers are sources of frozen fresh water, if humanity needed to, we may be able to recover fresh water by melting parts of glaciers. Explain how a tsunami happens. • A tsunami happens when an earthquake, volcanic eruption, or landslide happens deep below the ocean. • The resulting energy pushes some of the water upwards. • This force creates a wave that will eventually crash against a coastline Why are the rocks and stones found on beaches usually round and smooth? • Over time, the water moving over the rocks makes them smooth and round in shape (much like sandpaper does to wood). What does SCUBA stand for? • Self Contained Underwater Breathing Apparatus. When was Scuba diving invented? • In the 1940’s Name and describe 2 devices that humans use to explore the deep depths of the ocean. • Scuba gear • Submersibles • Sonar • Underwater Cameras What is meant by diversity? • Diversity is the presence of many different living things in one area. • The more living things that are present in one area, the more diverse that area is. Why does diversity tend to decrease the deeper you go in an ocean or a lake? • It decrease because the light does not penetrate • past a certain depth in the water and therefore plants cannot survive in deep water. No plants, less living things. Also, the deeper down we go, the greater the water pressure and harsher the environment (pitch black). Only some organisms are equipped to deal with these kind of conditions. Less living things means less diversity!