105W 100W 110W 95W 90W 85W 80W 75W 70W 65W 60W 55W 50W 45W 40W 35W 30W 25W 20W 15W 10W 5W 10E 15E 20E 25E 30E 35E 40E 45E 150E 155E 160E 165E 170E 175E 175W 170W 165W 160W 155W 150W 145W 5E 50E 55E 60E 65E 140W 135W 130W 125W 120W 70E 75E 80E 85E 90E 95E 100E 105E 110E 115E 120E 125E 130E 135E 140E 145E 180E-W 115W 0

85N ARCTIC OCEAN ARCTIC OCEAN 85N

80N 80N

75N 75N Greenland

EURASIA 70N 70N

PLATE 65N Iceland 65N F EURASIA Sweden Finland PLATE 60N Russia 60N Russia NORTH Norway Estonia

Canada Latvia

E 18 mm/yr Lithuania 55N 47 mm/yr & AMERICA 55N United Belarus

OKHOTSK

58 mm/yr Ireland Kingdom Germany Poland PLATE PLATE Belgium

E 50N E Czech 50N AMUR Republic

Slovakia Ukraine

Kazakhstan PLATE JUAN DE Kazakhstan 78 mm/yr FUCA PLATE F

73 mm/yr Austria Hungary Mongolia E France Romania 23 mm/yr Croatia 45N 39 mm/yr Serbia 45N Italy Bulgaria Uzbekistan

Kyrgyzstan E & 40N North Spain ANATOLIA Turkmenistan 40N Korea United States Portugal 92 mm/yr PLATE Turkey South AEGEAN NORTH & SEA PLATE

Korea Japan

45 mm/yr NORTH Syria

35N E 35N

China PACIFIC Afghanistan Iraq E ATLANTIC Tunisia OCEAN 9 mm/yr Iran F Morocco

OCEAN 23 mm/yr 27 mm/yr

30N Pakistan 30N E Nepal YANGTZE OKINAWA Pakistan PLATE PLATE Algeria Libya Egypt ARABIA 25N 48 mm/yr 25N Taiwan Western Sahara

India Myanmar RIVERA Mexico PLATE

(Burma) E PLATE F Saudi Arabia 20N Laos 94 mm/yr MARIANA 25 mm/yr Mauritania 20N PLATE PHILIPPINE Mali Oman INDIA SEA PLATE 63 mm/yr

Philippines E E Niger

CARIBBEAN Ye me n Thailand E PLATE 15N Senegal 15N PLATE 18 mm/yr Chad Cambodia F 61 mm/yr Burkina Sudan BURMA Faso PLATE 86 mm/yr Nicaragua Guinea 10N 10N COCOS Nigeria Somalia PANAMA Sierra PLATE Leone Cote F Sri PLATE SUNDA NORTH Venezuela Ethiopia Lanka PACIFIC Liberia d’Ivoire Ghana Central PLATE ANDES African Republic PLATE 27 mm/yr 5N 5N GALAPAGOS French Cameroon CAROLINE PLATE PLATE Colombia Guiana

PLATE Guyana Suriname Malaysia Kenya F Uganda 0 Indonesia MOLUCCA BIRD’S Gabon Democratic 30 mm/yr 0 SEA PLATE F Ecuador HEAD NORTH 50 mm/yr Republic PLATE MAOKE BISMARCK F NUBIA of the Congo SOUTH 70 mm/yr PLATE PLATE BISMARCK

Papua United 5S PLATE SOMALIA 5S BANDA SEA New F PLATE Republic

PLATE E Guinea SOLOMON of Tanzania

WOODLARK SEA PLATE E 151 mm/yr PLATE 106 mm/yr PLATE TIMOR 35 mm/yr 10S PLATE Peru F 10S Brazil SOUTH 70 mm/yr FUTUNA Angola BALMORAL ATLANTIC PLATE Zambia

15S INDIAN REEF PLATE Bolivia 15S NEW E NAZCA OCEAN OCEAN HEBRIDES NIUAFO`OU ALTIPLANO PLATE PLATE 237 mm/yr PLATE

Mozambique PLATE E Zimbabwe F 20S CONWAY F 79 mm/yr 20S TONGA 151 mm/yr

REEF PLATE SOUTH Namibia Madagascar E PLATE Paraguay 44 mm/yr 123 mm/yr Botswana EASTER 25S Australia SOUTH PLATE AMERICA 25S PACIFIC F 35 mm/yr OCEAN PLATE 30S South 30S

KERMADEC AUSTRALIA E Africa PLATE JUAN FERNANDEZ Uruguay 88 mm/yr Chile PLATE Argentina F 35S PLATE 35S 15 mm/yr F 59 mm/yr 40S 40S 72 mm/yr 40 mm/yr F & 94 mm/yr 45S 75 mm/yr F New Zealand 45S 14 mm/yr F

50S 20 mm/yr E F F 15 mm/yr 50S TRANSFORM 55S & SCOTIA 78 mm/yr 55S E PLATE SANDWICH PLATE

60S 60S SOUTHERN OCEAN SOUTHERN OCEAN F DIVERGENCE ANTARCTICA 65S 65S PLATE E CONVERGENCE 70S 70S PLATE BOUNDARY Converging

75S 75S Diverging

Transform 80S 80S Antarctica Seafloor Age (millions of years) 8 85S 85S

145W 140W 115W 160W 155W 150W 125W 120W 165E 170E 175E 180E-W175W 170W 165W 135W 130W 70E 75E 80E 85E 90E 95E 100E 105E 110E 115E 120E 125E 130E 135E 140E 145E 150E 155E 160E 0 5W 5E 10E 15E 20E 25E 30E 35E 40E 45E 50E 55E 60E 65E 0 50W 45W 40W 35W 30W 25W 20W 15W 10W 95W 90W 85W 80W 75W 70W 65W 60W 55W 20 40 60 80

110W 100 120 140 160 180 200 220 240 260 280 105W 100W

Plate Boundary - This map builds on the Tectonic Plates map by adding seafloor age data. Note that the youngest seafloor ages are found at the Referenced from Bird, Peter (2003) An updated digital model of mid-ocean spreading ridges, where new rock is constantly coming up from under the crust to heal the rifts formed as tectonic plates plate boundaries. (Orogen boundaries omitted.) Plate Convergence Vectors - move away from one another. Most new crust forms at these mid-ocean spreading ridges. Referenced from United States Geological Survey: Convergence data are shown by arrows describing direction and speed, relative to the plate across the boundary. The crust ages as it moves away from the spreading ridges, and eventually gets pushed back into the Earth in a subduction zone. SEAFLOORSEAFLOOR AGEAGE Plate Divergence Vectors - Because oceanic crust subducts more easily than continental crust, all of the seafloor eventually is recycled by subduction while Referenced from Digital Tectonic Activity Map: Divergence data are shown by double arrows describing direction and speed. very little continental crust is consumed in subduction. The result is that the oldest oceanic crust is still much younger than the Seafloor Age - oldest continental crust. Referenced from Muller, R.D., M. Sdrolias, C. Gaina, and W.R. Roest 2008. Age, spreading rates and spreading symmetry of the world’s ocean crust, Geochem. Geophys. Geosyst., 9, Q04006, The oldest seafloor in the world is found in the Mediterranean Sea. The next oldest seafloor ages are found in the northeastern doi:10.1029/2007GC001743. Atlantic and the northeastern Pacific, far from any spreading ridges. The northeastern Pacific also has a long convergent boundary, Projection: Robinson (World) where some of the oldest seafloor is now being subducted back into the interior of the Earth. In areas where spreading rates are Produced by slow, seafloor age changes quickly as you move away from the spreading ridge. Conversely, in areas where spreading rates are California Institute of Technology Tectonics Observatory fast, seafloor age changes more slowly as you move away from the spreading ridge. April 2009