Fig 4 CO p 97 Fig 4 1

Fig. 4 -CO, p. 97

Fig. 4 -1, p. 99

Fig. 4 -2 a, p. 100

Beam of sound waves travels to bottom and is reflected back to ship Depth = V (T/2) Fig. 4 -2 a, p. 100

Fig. 4 -2 b, p. 100

Seafloor True depth immediately beneath vessel Measured depth equals true depth Sound beam emitted by echo sounder (beam angle is exaggerated) Measured depth is less than actual depth Fig. 4 -2 b, p. 100

Fig. 4 -2 c, p. 100

Fig. 4 -3, p. 101

Fig. 4 -4 a, p. 101

Fig. 4 -4 b, p. 101

Box 4 -1 a, p. 102

Box 4 -1 b, p. 103

500 1, 500 2, 000 − 200 − 400 2, 500 − 600 X (m) Depth (m) 1, 000 − 800 3, 000 − 5, 500 Y (m) − 6, 000 Box 4 -1 b, p. 103

Box 4 -1 c, p. 103

Latitude 49 46. 5 49 46. 0 49 45. 5 − 130 − 16. 0 − 15. 5 Longitude − 130 − 15. 0 Box 4 -1 c, p. 103

Fig. 4 -5 a, p. 104

Geosat Orbit h Sea Surface or Ocean o afl e S Crust Fig. 4 -5 b, p. 104

Fig. 4 -5 c, p. 104

Fig. 4 -6, p. 105

Fig. 4 -6 a, p. 105

Fig. 4 -6 b, p. 105

Atlantic Ridge 0 100 200 300 400 500 Horizontal scale in nautical miles 0 200 400 600 800 926 Horizontal scale in kilometers Vertical x 100 15, 000 10, 000 5, 000 0 – 5, 000 – 10, 000 – 15, 000 Africa – 20, 000 Depth in feet Depth in meters – 1, 524 – 3, 048 – 4, 572 – 6, 096 South America Rocky Mountains Appalachian Mountains Height in feet Height in meters 4, 572 Sierra Nevada 3, 048 1, 524 0 Fig. 4 -6 b, p. 105

Fig. 4 -7, p. 105

Mean land elevation 840 m (2, 760 ft) Sea level Mean depth of sea 3, 796 m (12, 451 ft) Elevation (miles) Mount Everest 8. 85 km (5. 5 mi) Depth (miles) Depth (kilometers) Elevation (kilometers) Earth’s area (hundreds of millions of square kilometers) Mariana Trench ~11 km % Earth’s area at this elevation or higher Fig. 4 -7, p. 105

Fig. 4 -8, p. 106

Continental margin Deep-ocean basin Submarine canyon profile (cut through continental shelf) Sediment Continental shelf Continental slope Oceanic Continental rise ridge Sediment Continental crust (granitic) Oceanic crust (basaltic) Asthenosphere crust (basaltic) Fig. 4 -8, p. 106

Fig. 4 -9, p. 106

Oceanic ridges 22. 1% Continental mountains 10. 3% Continental lowlands 18. 9% Ocean basin floors 29. 8% Volcanic island arcs, trenches, submarine volcanoes, and hills 3. 7% Continental shelves and slopes 11. 4% Continental rise 3. 8% Oceanic crust Continental crust Fig. 4 -9, p. 106

Fig. 4 -10, p. 107

Narrow A continental passive shelf Peru–Chile margin Plate Andes Plate boundary Trench boundary Mountains Broad South America continental shelf Atlantic Pacific Ocean South American Ocean Deep basin Plate African Plate Nazca Plate movement Subduction zone Mid-Atlantic Ridge (deep and shallow (spreading centers, earthquakes) shallow earthquakes) An active margin Fig. 4 -10, p. 107

Fig. 4 -11, p. 108

Distance from shore (miles) 1 2 3 4 Depth (km) 5 Continental shelf 200 300 400 500 600 700 Continental margin Sea level 0 Shelf break (~140 m, 460 ft) Continental rise 1 (sediment thickness varies) 2 Deep-ocean floor Depth (miles) 0 100 Continental slope Depth (km) 0 3 0 100 200 300 400 500 600 700 800 900 1, 000 1, 100 1, 200 Vertical exaggeration 50: 1. Distance from shore (km) Sea level 0 4 0 100 200 300 400 500 600 700 800 900 1, 000 1, 100 1, 200 No vertical exaggeration. Fig. 4 -11, p. 108

Fig. 4 -12, p. 108

Fig. 4 -13, p. 109

Fig. 4 -14, p. 109

Fig. 4 -15, p. 110

0 0 Height above or below present sea level (ft) Height above or below present sea level (m) Today’s sea level – 426 – 130 0 50, 000 100, 000 150, 000 Years before present 200, 000 250, 000 Fig. 4 -15, p. 110

Fig. 4 -16, p. 111

Canyon heads Continental shelf Continental slope Distribution channel Shelf break Deepsea fan Fig. 4 -16, p. 111

Fig. 4 -17, p. 111

Fig. 4 -18, p. 112

Fig. 4 -19, p. 112

Fig. 4 -20, p. 112

Feet 0 1 1 2 2 3 3 4 5 Miles 6 Kilometers Meters 14, 400 4, 390 15, 000 4, 570 15, 600 4, 760 Depth Fig. 4 -20, p. 112

Fig. 4 -21 a, p. 114

Mid-Atlantic Ridge Juan de Fuca Ridge 2. 6 East Pacific Rise (Ridge) 3. 8 15. 7 6. 4 10. 7 9. 5 Pacific–Antarctic Ridge 5. 5 2. 8 9. 5 1. 5 6. 4 Fig. 4 -21 a, p. 114

Fig. 4 -21 b, p. 114

Fig. 4 -22, p. 115

Fig. 4 -23 a, p. 116

Fig. 4 -23 b, p. 116

3, 940 meters; 12, 000 feet 28°N 50°W 4, 400 meters; 14, 400 feet 5, 860 meters; 19, 200 feet 10 miles 16 kilometers Fig. 4 -23 b, p. 116

Fig. 4 -24, pp. 116 -117

Fig. 4 -25, p. 118

Plate boundary Oceanic ridge Adjacent sections Sections here move in opposite same directions Fracture zone (inactive) Transform fault (active part of fracture zone) Adjacent sections here move in same direction Fracture zone (inactive) Lithosphere Asthenosphere Fig. 4 -25, p. 118

Fig. 4 -26, p. 119

Fig. 4 -27, p. 119

3 2 Distance (km) 1 0 1 2 1 0 Distance (mi) 3 2 Spreading axis 0 0 1 2 1 Depth (mi) Depth (km) Hydrothermal vents and black smokers Zone of leaching Ascending superheated seawater Descending seawater Magma chamber Fig. 4 -27, p. 119

Fig. 4 -28, p. 120

Fig. 4 -29 a, p. 120

Inactive sinking volcano being "shaved" at ocean surface Older, extinct volcanoes Active volcanoes Older, extinct volcanoes Spreading center Sea level S G G Magma chambers Lithosphere Asthenosphere 50 40 G = guyot S = seamount 30 20 10 20 30 40 50 Age of ocean floor (millions of years) Fig. 4 -29 a, p. 120

Fig. 4 -29 b, p. 121

169° 08'W 168° 04'W 14° 12'S 169° 00'W 14° 16'S 168° 56'W 168° 52'W 14° 20'S 14° 24'S − 5, 000 − 4, 000 − 3, 000 − 2, 000 − 16, 404 − 13, 123 − 9, 843 − 6, 562 0 Depth (m) − 3, 281 0 Depth (ft) Fig. 4 -29 b, p. 121

Fig. 4 -29 c, p. 121

Fig. 4 -30, p. 122

Kuril Trench Philippine Trench Aleutian Japan Trench Mariana Trench Challenger Deep Java Trench New Hebrides Trench Puerto Rico Trench Middle America Kermadec– Trench Tonga Peru–Chile Trench South Sandwich Trench Fig. 4 -30, p. 122

Fig. 4 -31, p. 123

Mariana Trench Challenger Deep Guam Pacific Ocean Mount Everest (. . . same scale) Depth (mi) Depth (km) Guam Mariana Trench Fig. 4 -31, p. 123

Fig. 4 -32, pp. 124 -125