Part IV: The Importance of Oceanic & Continental Crust A. Understanding the Hypsometric Curve The hypsometric curve is the graph below. This curve is typically used to demonstrate that the Earth has two types of crust, continental and oceanic. The curve shows the percentage of the Earth's surface above any elevation. The horizontal axis, labeled "% of Earth's surface," gives the percentage while the vertical axis shows elevation above or below sea level. Although there is Other information on this plot, our focus will be on dark curve that crosses the plot. Note that the curved line crosses the y-axis at about 6 km Similarly, the line crosses the x-axis when y=-12 km and x=100% Remember, there are two variables plotted on this graph (elevation and % of Earth's surface). Typically you will be given a value for one of these variables, and you will determine the value of the other. When you are given a percentage, read it on the horizontal axis and go up until you reach the curve. Then draw a line across to the vertical axis, and read the answer, the elevation above which the given percent of the Earth's surface can be found. On the other hand, when given an elevation, you draw a horizontal line to the curve, drop a line down to the bottom axis and read the percentage. This is easier to understand using an example. Example #1: Using the hypsometric curve, determine the minimum elevation of mountains that make up the highest 10% of Hypsometric Curve the Earth's surface. Let's take it step by step. Mountains 1. Find 10% on the horizontal axis. 2.Draw a line up from 10% until it reaches Continental interiors (plains) Deep the hypsometric curve. Continental shelf trenches 4. Now draw a line across to the vertical axis. Ocean floor 3. You find that 10% of the Earth's surface has an elevation of 0.5 km or higher. 8 6 4 Elevation (km) - - 8 Example #2: Determining % of Earth's surface above sea level. 1. Find 0 km (sea level) on the vertical axis. 2. Draw a line across from 0 lm until it reaches the hypsometric curve. 3. Now, drop a line until it intersects the horizontal axis (between 20% and 40%). 4. The point is a little closer to 20% so let's call it 29%. So, you find that 29% of the Earth's surface is above sea level -10 0 20 80 100 40 60 % of Earth's surface Part A Practice Questions: 1. Practice reading the Hypsometric Curve to answer the following questions. A. You want to create a submarine that allows you to can gain access to at least 80% of the Earth's surface, including the continents. How deep into the ocean can this submarine go? (80% of the Earth's surface is above what depth in the ocean)? (2pts) The submarine can go down up to around 5 to 6 km below the ocean or a better approximation, 5.5 km. B. You've just invented a new alloy for a submarine that can withstand underwater pressures to a depth of 4.5 km below sea level. If this is the maximum depth to which an oceanographer interested in the sea floor could go, what percentage of the Earth's surface is inaccessible to your ocean floor study? (2pts) 100% -60% = 40% 40% of the earth's surface is inaccessible to our ocean floor study. C. Most plants cannot exist above 4 km above sea level. What percent of the Earth's surface is higher than this? (2pts) 2% of the Earth's surface is above 4 km. D. Most oceanic fish cannot live in depths below 4 kn below sea level, and obviously can't live in areas that are above sea level. What percentage of the Earth can they occupy that is what percentage of the Earth's surface is between 4 kilometers below sea level and sea level? (2pts) 18% of the Earth is below sea level but higher than 4 km below sea level. - Taimum height 8.15 km 8 high mountain ranges altitude om! fund seine average height of land 10.Blum 2 2 2 continental shell 2009 0 0 8.5 30 continental stepe 2 average depth of sea (3.7km T depth km - 164 6 00 1.0 manimum depth (11.04 km) 10 0 30 20 10 100 10 20 40 percentage of the Earth's surface 60 Cumulative percentage 2. Now that you are more proficient at reading information from the Hypsometric Curve, it is time think about how this information applies to our investigation of plate tectonics. To aid in this process, the diagram below includes the histogram of raw data that was used to construct the Hypsometric Curve 11 -nasun legs high routh ang de 1.1 arengute w 4 contra el 2 peetha udo TES 30 41 1110 122 16.4 10 dem c Un ehk 1 1 1 10 20 30 40 Decor of the Earth's te 81 CREO! A. Describe the distribution of elevation on Earth? Hint: While there is a great range in elevations on the Earth. -85% of the Earth's surface fall into two narrow bands of devaticewhat are they? What is this type of distribution called?) (2pts) B. What might explain this distribution of elevation on Earth? What does the Hypotuotre Curve porsche evidence for?) (2pts) 3. Now compare the Earth's Hypsometric Curve with the moon's. +10 A What is missing from the moon's hypsometric curve? (1pt) +55 Hypsometric curves B. Why does the information support the theory that the moon lacks active tectonics ? (1pt) Moon E -5- Eorth 50 100 Percentage of surface Part IV: The Importance of Oceanic & Continental Crust A. Understanding the Hypsometric Curve The hypsometric curve is the graph below. This curve is typically used to demonstrate that the Earth has two types of crust, continental and oceanic. The curve shows the percentage of the Earth's surface above any elevation. The horizontal axis, labeled "% of Earth's surface," gives the percentage while the vertical axis shows elevation above or below sea level. Although there is Other information on this plot, our focus will be on dark curve that crosses the plot. Note that the curved line crosses the y-axis at about 6 km Similarly, the line crosses the x-axis when y=-12 km and x=100% Remember, there are two variables plotted on this graph (elevation and % of Earth's surface). Typically you will be given a value for one of these variables, and you will determine the value of the other. When you are given a percentage, read it on the horizontal axis and go up until you reach the curve. Then draw a line across to the vertical axis, and read the answer, the elevation above which the given percent of the Earth's surface can be found. On the other hand, when given an elevation, you draw a horizontal line to the curve, drop a line down to the bottom axis and read the percentage. This is easier to understand using an example. Example #1: Using the hypsometric curve, determine the minimum elevation of mountains that make up the highest 10% of Hypsometric Curve the Earth's surface. Let's take it step by step. Mountains 1. Find 10% on the horizontal axis. 2.Draw a line up from 10% until it reaches Continental interiors (plains) Deep the hypsometric curve. Continental shelf trenches 4. Now draw a line across to the vertical axis. Ocean floor 3. You find that 10% of the Earth's surface has an elevation of 0.5 km or higher. 8 6 4 Elevation (km) - - 8 Example #2: Determining % of Earth's surface above sea level. 1. Find 0 km (sea level) on the vertical axis. 2. Draw a line across from 0 lm until it reaches the hypsometric curve. 3. Now, drop a line until it intersects the horizontal axis (between 20% and 40%). 4. The point is a little closer to 20% so let's call it 29%. So, you find that 29% of the Earth's surface is above sea level -10 0 20 80 100 40 60 % of Earth's surface Part A Practice Questions: 1. Practice reading the Hypsometric Curve to answer the following questions. A. You want to create a submarine that allows you to can gain access to at least 80% of the Earth's surface, including the continents. How deep into the ocean can this submarine go? (80% of the Earth's surface is above what depth in the ocean)? (2pts) The submarine can go down up to around 5 to 6 km below the ocean or a better approximation, 5.5 km. B. You've just invented a new alloy for a submarine that can withstand underwater pressures to a depth of 4.5 km below sea level. If this is the maximum depth to which an oceanographer interested in the sea floor could go, what percentage of the Earth's surface is inaccessible to your ocean floor study? (2pts) 100% -60% = 40% 40% of the earth's surface is inaccessible to our ocean floor study. C. Most plants cannot exist above 4 km above sea level. What percent of the Earth's surface is higher than this? (2pts) 2% of the Earth's surface is above 4 km. D. Most oceanic fish cannot live in depths below 4 kn below sea level, and obviously can't live in areas that are above sea level. What percentage of the Earth can they occupy that is what percentage of the Earth's surface is between 4 kilometers below sea level and sea level? (2pts) 18% of the Earth is below sea level but higher than 4 km below sea level. - Taimum height 8.15 km 8 high mountain ranges altitude om! fund seine average height of land 10.Blum 2 2 2 continental shell 2009 0 0 8.5 30 continental stepe 2 average depth of sea (3.7km T depth km - 164 6 00 1.0 manimum depth (11.04 km) 10 0 30 20 10 100 10 20 40 percentage of the Earth's surface 60 Cumulative percentage 2. Now that you are more proficient at reading information from the Hypsometric Curve, it is time think about how this information applies to our investigation of plate tectonics. To aid in this process, the diagram below includes the histogram of raw data that was used to construct the Hypsometric Curve 11 -nasun legs high routh ang de 1.1 arengute w 4 contra el 2 peetha udo TES 30 41 1110 122 16.4 10 dem c Un ehk 1 1 1 10 20 30 40 Decor of the Earth's te 81 CREO! A. Describe the distribution of elevation on Earth? Hint: While there is a great range in elevations on the Earth. -85% of the Earth's surface fall into two narrow bands of devaticewhat are they? What is this type of distribution called?) (2pts) B. What might explain this distribution of elevation on Earth? What does the Hypotuotre Curve porsche evidence for?) (2pts) 3. Now compare the Earth's Hypsometric Curve with the moon's. +10 A What is missing from the moon's hypsometric curve? (1pt) +55 Hypsometric curves B. Why does the information support the theory that the moon lacks active tectonics ? (1pt) Moon E -5- Eorth 50 100 Percentage of surface