Erosion and Deposition I. Landforms – physical shapes of the land a. Examples include hillsides, cliffs, and marshes b. Wetlands – areas characterized by a high proportion of water c. Marshes – wetlands dominated by grasses, which a swamp is designated by trees II. Topography – Shape of the land a. Topographic Maps are used to show topography b. Contour lines – lines that connect all the areas that are the same height relative to sea level c. Contour intervals – the height difference between the contour line i. When the contour lines are closer together they represent a steeper incline d. Stability – the more topography changes over time, the less stable that land is said to be III. Mean, Median and Mode a. Mean – also known as the average, is the sum of all values divided by the total number of values b. Median – the middle value when the data is arranged in order c. Mode – the most common value in a set of numbers d. Places that water comes from: i. Rain ii. River flow from mountains iii. Ocean waves hitting the beach e. Flooding is when a lot of water falls or melts in a short amount of time f. Rainfall Pattern is the typical amount of water an area receives from rain IV. Sediments – materials that settle out of the water a. Delta – a fan shaped area of land at a river’s mouth that bulges into the bay b. River channel – the riverbed is carved into the land c. Sediment is created by the earth process of weathering d. Weathering – the process of breaking down rocks V. Earth Processes – Dynamic actions that occur both on the earth’s surface and inside the earth a. Erosion – when surface soil, and rock are worn away through the action of glaciers, water and wind i. Is a destructive process because it destroys the land b. Deposition -- the act of depositing eroded sediment in a new location i. VI. Is a constructive process because it builds land Scientists a. Geologist – studies rocks, minerals and other non-living (i.e. abiotic) parts of the earth b. Engineer – uses scientific knowledge to solve practical problems; involved in designing most items that are used in everyday life c. Ecologist – studies the interrelations of organisms with each other and with their environment VII. Variables – any factor that can have any number of possible values depending on the situation a. Controlled variable – held constant (i.e. did not change) or whose impact is removed in order to analyze the relationship between other variables without interference b. Tested variable – changed in s systematic way in order to determine its effect c. Uncontrolled Variable – variable that is neither controlled nor tested in an experiment VIII. Cliff Erosion a. Cliff erosion is caused by waves and begins below the water line b. 3 Basic Types of Erosion Control Structures: i. Breakwaters ii. Seawalls/ripraps iii. Jetty