Measuring Our World Exercise 1 Introduce yourself. Mention the email not working for the first 3 weeks of class. Tell them that this will be frustrating but that’s OK.
Informational material Link to exercise can be found on the syllabus page Tutorials for Google Earth PRO and Acme Mapper can be found on the syllabus page Answers are to be submitted in D2L Assessments Quizzes Exercise 1 Exercise will take 3-6 hours NEED: Ruler with metric and standard units Calculator Printer Go to the course syllabus and show them where the exercise is located Show them the tutorials on the right-hand side Go to D2L and show them where to submit the answers-they get unlimited time
Visualizing “Topography” Topography- a mapping scheme that allows for a more detailed representation of landscape Visualize relief (changes in elevation across a landscape) Utilizes contour lines
Contours How do we visualize relief? Contour lines Interpolation Lines of the same elevation Interpolation Connecting known elevations Tip-contour lines that are close together indicate greater relief and steeper slopes Interpolation Remember that relief is the change in elevation across a landscape There will be a question on the exercise that asks what closely-spaced contour lines tell you.
Mt. Hood, Oregon The photo on the left depicts a profile view of Mt. Hood The map on the right gives a birds-eye view looking down on Mt. Hood The contour lines on the map allow for the visualization of a three dimensional object on a two-dimensional map
Contour lines Different type of contours Index Intermediate Supplementary Depression What type of line is being pointed at by the red arrow? There are four major types of contour lines. -Index contour lines will always be in bold and are usually labeled but not always! -Intermediate lines -Supplementary -Depression contours indicate low-lying areas and have small ticks pointing inward
Topographic Map Scale Unitless number- independent of map size Scale Fractional Scale Scale Fractional Scale (Representative Fraction) Ex) 1:24,000, 1:62,500, 1:125,000 Unitless number- independent of map size Scale bar Associated with units (miles, km, ft., etc.) Dependent on map size Effective for quick visualization of distance Which scale is larger? Map scales can be represented as fractional scales or scale bars You will only encounter questions related to fractional scales in the exercise The top scale is larger because 1 divided by 24,000 is a larger fraction than one divided by 125,000 Scale Bar
Measuring on a Topographic Map Using Ruler Remembering Fractional Scale Multiply Need to Convert? Ex) Campground Minnemishinona Falls Map = 1:24,000 Fractional Scale Measured 1.95 inches with ruler 1.95 in x 24,000 = 46,800 in Need to convert to feet? 46,800 in / 12 in = 3,900 feet There will be a question that asks you to print off a map and use the fractional scale of 1:24,000. Because you are using the fractional scale it doesn’t matter how the map is printed out. One inch on the map equals 24,000 inches in real life. So if the distance between the campground is 1.95 inches then the distance in real life is 1.95 inches multiplied by 24, 000.
Determining Slope Often want to know slope as a percentage Slope is equal to the change in elevation divided by the change in horizontal distance (multiplied by 100 to get a percentage) Referred to as Rise / Run Ex) Starting elevation:1,000ft. Ending Elevation: 1,200ft Distance Traveled: 10,000 feet = RUN 1,200 feet – 1,000 feet = 200 feet (RISE) 10,000 feet (RUN) 200 feet / 10,000 feet = 0.02 (UNITS CANCEL OUT) 0.02 x 100 = 2% (THIS IS OUR SLOPE)
Digital Elevation Models (DEM) Another way to represent elevation data Assigns elevation values to pixels within an image Grid placed over area of interest with known elevation Elevation data produced at equal spacing Known as sampling interval Sample interval is also known as the resolution Ex) A 30 meter DEM is sampled every 30 meters Result is continuous surface reflecting the surface topography Imagine each pixel in this grid represents 30 square meters. Therefore that 30 sq. meter area would represent a single elevation. Now imagine that each pixel in the grid represents 1 square meter so that every square meter represents a single elevation.
30 meter DEM 1 meter DEM
Google Earth Pro walkthrough to making a slope profile Go to google earth pro and do a slope profile form Ellis Ave to Stoltzman and from the summit of Mt. Hood to its base.
Volcanoes and Diastrophism (faulting) In Exercise 1 you will encounter questions related to volcanic landforms as and faults Will be tasked with interpreting what type they are based on physical characteristics
Volcanic Landforms and Activity Types of Volcanoes Composite (Strato) Conical Shape Steep Slopes Formed by Alternating Layers of Lava and Pyroclastic Flow (mafic and felsic) High Viscosity Flow Ex. Mt. Hood Shield Cinder Cone Hotspots Ex) Yellowstone, Hawaiian Islands
Volcanic Landforms and Activity Types of Volcanoes Composite (Strato) Shield Shape Like a Warrior’s Shield Low Slopes Periodic Lava Flows Low Viscosity Flow (mafic) Cinder Cone Hotspots Ex) Yellowstone, Hawaiian Islands
Volcanic Landforms and Activity Types of Volcanoes Composite (Strato) Shield Cinder Cone Small Conical Hill Shape Made of accumulating Pyroclastic Material and Scoria Erupts from Single Base and Settles Near Vent Can Form Rapidly Hotspots Ex) Yellowstone, Hawaiian Islands
Volcanic Landforms and Activity Types of Volcanoes Composite (Strato) Shield Cinder Cone Hotspots Plume of Magma Rising Through Upper Mantle Can result in island arcs and geothermal activity Ex) Yellowstone, Hawaiian Islands http://www.nps.gov/features/yell/tours/fountainpaint/images/hotspot_yell2.gif
Hawaii as a hotspot Direction of crust movement Hot spot remains stationary but the crust moves westward Forms from oceanic crust which produces mafic lava (low viscosity) Just because Hawaii is a hotspot doesn’t mean that it can’t have composite, shield, or cinder cone volcanoes.
Faulting and Tectonic Activity Types of Faulting Extensional Faulting Divergent Plate Boundaries Upwelling magma forces crust apart Normal Faults – Hanging wall is downthrown, footwall is upthrown Horsts and Grabens Basin and Range territory Strike-Slip Faulting Compressional Faulting https://www.nature.nps.gov/geology/education/images/GRAPHICS/basin_and_range.jpg
Faulting and Tectonic Activity Types of Faulting Extensional Faulting Strike-Slip Faulting Transform Boundaries 2 Main Types: Right-Lateral Left-Lateral Can lead to offset drainages Compressional Faulting
Faulting and Tectonic Activity Types of Faulting Extensional Faulting Strike-Slip Faulting Compressional Faulting Converging Plate Boundaries Thrust and Reverse Faulting- Hanging wall is upthrown, footwall is downthrown Thrust fault is usually more shallow and has more horizontal displacement
Acme Mapper Topographic map webpage Map scale changes as you zoom Can pinpoint latitude/longitude points on the map and place markers Tutorial can be found on the syllabus page under Acme Mapper Tutorial You can copy and past coordinates from the exercise into the search box of acme mapper
Google Earth Pro Make sure to download GOOGLE EARTH PRO - NOT GOOGLE EARTH Mapping software that allows us to: Measure distances and areas Place precise points Calculate slope See current and historic satellite imagery Tutorial can be found on the syllabus page under Google Earth Pro Tutorial You will have to download google earth pro, be sure that it is not just google earth
Due October 3RD by 11:59 Pm Submit answers on D2l