120117a-Bathymetry-StartR

120117a-Bathymetry-StartR - 1/19/12 BATHYMETRY Observations...

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Unformatted text preview: 1/19/12 BATHYMETRY Observations (facts) Patterns Synthesis Hypotheses or Theory (explanation grounded in data and patterns of data) Goals and Objectives Understand what methods were used historically and are used today to make observations about the bathymetry of the oceans Examine the patterns of ocean bathymetry Understand the connections between ocean bathymetry, the origin of ocean basins, and the theory of plate tectonics Goals and Objectives Understand what methods were used historically and are used today to make observations about the bathymetry of the oceans Examine the patterns of ocean bathymetry Understand the connections between ocean bathymetry, the origin of ocean basins, and the theory of plate tectonics As new data emerges, new patterns might emerge, and new syntheses and explanations might emerge. It took centuries to develop a map of the earth Garrison, 2008 Coordinate system - but not numeric Elevations of Earth above sea level: ( topography ) 1 1/19/12 To make a bathymetric (or topograhic) map, need to know: 1. Depth (or elevation) relative to sea level 2. Location on Earth Eye level - relative elevation (elevation change) eye height stadia height Use multiple measurements to measure changes over longer lateral or vertical distance. Using the Eye Level Surveying Equipment 1. level on a tripod 2. tape measure (horizontal) 3. stadia rod (vertical) http://www.marinebio.net/ marinescience/01intro/ tomeas.htm Photo by: Mark R. Boardman! Sophisticated eye-level on a tripod. 2 1/19/12 Bench Mark (frame of reference) Photo by: Mark R. Boardman! Sophisticated eye level, stadia rod, measuring tape. Person in stream is part of a second measuring team. This survey mark, first set in 1917, is a bench mark, meaning it marks a point whose elevation above or below a geodetic vertical datum is known. Bench marks are just one type of survey mark set by the National Geodetic Survey and its predecessor organizations. celebrating200years.noaa.go Greenwich, England http:// upload.wikimedia.org/ wikipedia/commons/c/c6/ Primemeridian.jpg http://upload.wikimedia.org/ wikipedia/commons/6/6e/ Prime-meridian.jpg Bench mark ? Frame of reference ? Location ? How do you know where you are at sea ? http://www.csulb.edu/~dsidorov/PhotoContest/ Images/__Konishi---On-prime-meridian.jpg http://www.mlewallpapers.com/image/ 16x9-Widescreen-1/view/St-Lucia-HorizonI-321.jpg 3 1/19/12 Bench mark ? Frame of reference ? Location ? Lots of educated guesswork dead reckoning angle from horizon is your latitude http://www.m4040.com/Survival/ Skills/Navigation/Navigation.htm http://www.mlewallpapers.com/image/ 16x9-Widescreen-1/view/St-Lucia-HorizonI-321.jpg Southern Hemisphere Noon shot calculations using the angle from Southern Cross http://static.howstuffworks.com/gif/true-north-illustration-3.jpg Trujillo and Thurman, 2010! Local Apparent Noon LAN For latitude: need to know the day of the year. e.g. on June 22, 23.5 north on Sept 21, 0 north (equator) depends on day of year http://www.navigation-spreadsheets.com/noon_shots.html http://www.navigation-spreadsheets.com/noon_shots.html 4 1/19/12 But location east or west Measure speed and direction; multiply by days = location http://www.mlewallpapers.com/image/ 16x9-Widescreen-1/view/St-Lucia-HorizonI-321.jpg http://www.mlewallpapers.com/image/ 16x9-Widescreen-1/view/St-Lucia-HorizonI-321.jpg Log floats, not pulled through the water Log line: 150 fathoms knots every 47 3 time: 28 seconds number of knots in 28 seconds = speed (nautical mile = 6080 feet) http://www.twogreens.co.uk/ wakeup/lifeatsea/logline.htm http://www.twogreens.co.uk/wakeup/images/loglineinuse.gif Measure speed and direction; multiply by days = location BUT wind drift, speed changes, ocean currents http://www.mlewallpapers.com/image/ 16x9-Widescreen-1/view/St-Lucia-HorizonI-321.jpg Longitude Act 1714 The main longitude prize was:! "20,000 for a method that could determine longitude within 30 nautical miles (56#km).! http://www.mlewallpapers.com/image/ 16x9-Widescreen-1/view/St-Lucia-HorizonI-321.jpg 5 1/19/12 360/24 hours = 15 per hour 360/24 hours = 15 per hour = 0.25 per minute of time http://www.geographicguide.com/pictures/maps/time-zones.gif http://www.geographicguide.com/pictures/maps/time-zones.gif 360/24 hours = 15 per hour = 0.25 per minute of time one minute = 13 miles (at 40N) Noon shot http://www.geographicguide.com/pictures/maps/time-zones.gif Trujillo and Thurman, 2010! Time at sea Longitude Act 1714 The main longitude prize was:! "20,000 for a method that could determine longitude within 30 nautical miles (56#km).! http://www.visualparadox.com/ images/no-linking-allowed-main/ hourglass.jpg http://www.mlewallpapers.com/image/ 16x9-Widescreen-1/view/St-Lucia-HorizonI-321.jpg 6 1/19/12 Marine Chronometer John Harrison How to determine depth http://upload.wikimedia.org/wikipedia/commons/1/14/Harrison %27s_Chronometer_H5.JPG Sounding line and weight Hours per cast http://www.punaridge.org/ doc/factoids/Sound/ EchosoundingFig1.jpg http://www.marinebio.net/marinescience/01intro/toimg/sounder.jpg Sounding line and weight wax on weight http://www.marinebio.net/marinescience/01intro/toimg/sounder.jpg http:// www.aquariumofpacific.org/ 7 1/19/12 http://www.aquariumofpacific.org/ oceanexplorer.noaa.gov/history/breakthru/media/12_gulfbathy_600.jpg http://celebrating200years.noaa.gov/events/survey/gulf_of_mexico650.jpg http://www.portpublishing.com/ HMS Challenger 1872-1876 starcentral.mbl.edu http://oceanexplorer.noaa.gov/explorations/03mountains/background/ challenger/media/route.html Depthof rope: 144 miles miles soundings made:492 (360?) accuracy of depth: 150 feet weight used: 450 pounds time to bottom: !1 hour HMS Challenger 1872-1876 Scientists: 6 8 1/19/12 Sounding weight used by the Challenger expedition Pre-Challenger Bathymetry ! 450 pound weight ! 1 meter corer / sampler http://www.photolib.noaa.gov/bigs/map00022.jpg Challenger Sampling Sites (red) Map of the Atlantic Ocean published after the outward bound segment of the CHALLENGER Expedition. www.photolib.noaa.gov/ htmls/map00023.htm Map of the Atlantic Ocean published after the outward bound segment of the CHALLENGER Expedition. will be examined on inbound leg www.photolib.noaa.gov/ htmls/map00023.htm Contour Map of the Atlantic Published by Sir Wyville Thomson of the CHALLENGER Expedition in 1877. The first ever to show the continuity of the Mid-Atlantic Ridge. The N-S line in the south Atlantic followed the ridge and is among the most important survey lines ever run. http://www.photolib.noaa.gov/ bigs/map00026.jpg 9 1/19/12 inbound track Sir John Murray's map of the Atlantic Ocean, Chart 1A, accompanying the Summary of Results of the Challenger Expedition, 1895. www.photolib.noaa.gov/ htmls/map00039.htm Summary of Results of the Challenger Expedition, 1895. www.photolib.noaa.gov/ htmls/map00039.htm Sir John Murray's map of the Atlantic Ocean, Chart 1A, accompanying the Summary of Results of the Challenger Expedition, 1895. REMOTE SENSING: www.photolib.noaa.gov/ htmls/map00039.htm Indirect methods of seeing REMOTE SENSING: Indirect methods of seeing REMOTE SENSING: Indirect methods of seeing television, telephone, a stethoscope, television, telephone, a stethoscope, x-rays, photography, mirrors, 10 1/19/12 REMOTE SENSING: Indirect methods of seeing Echosounding television, telephone, a stethoscope, x-rays, photography, mirrors, ultrasound, NMR, doppler, radar, ... Germany 1925 Meteor Garrison, 2008 Remote Sensing using SOUND Sea surface Sediment surface Trujillo and Thurman, 2010 Bottom of the Ocean UP Vertical Exaggeration Sediment layers 11 1/19/12 Trujillo and Thurman, 2010! Trujillo and Thurman, 2010! SONAR Ship s Tracks - Atlantic Ocean bbs.keyhole.com topex.ucsd.edu/marine_topo/gif_topo_track/ tracks10.gif topex.ucsd.edu/marine_topo/gif_topo_track/ tracks10.gif 12 1/19/12 END LECTURE 12-01-17 13 ...
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This note was uploaded on 02/15/2012 for the course GLG 244 taught by Professor Sikorski during the Spring '05 term at Miami University.

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