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Breakup of Pangea  (200 mya - Present)

 

Seafloor Spreading in the Atlantic, Indian and Pacific Oceans

(to run animation, drag mouse across image)

(Read the explanation below, while you wait for the animation to load.)

This animation shows the  breakup of Pangea and the pattern of seafloor spreading that created the Atlantic, Indian and Pacific Oceans during the last 150 million years.  Plate tectonics is the theory that describes how the outermost, rigid layer of the Earth has moved through time.  When plates converge they collide and a one plate dives back down into the Earth in a region called a subduction zone.  Earthquakes and volcanoes occur in the vicinity of subduction zones.  When plates move apart, a crack or rift forms in the middle of the ocean.   This rift is sometimes also called the "mid-ocean ridge".  New ocean floor is produced at the mid-ocean ridge by a process called "sea floor spreading".   This animation shows how sea floor spreading during the past 150 million years produced the modern ocean basins.

The colors in the animation illustrate both the age of the ocean floor and the symmetry of sea floor spreading.   The colors on either side of the mid-ocean ridge match because the ocean floor is the same age.  As the sea floor spreads, a symmetrical rainbow-colored pattern  is produced.  The colors shown in this animation roughly correspond to the following ages of ocean floor:  red - modern,  orange - 20 million years, yellow - 40 million years, light green - 60 million years, light blue - 100 million years, dark blue - 120 million years.  The colors repeat once more for older ocean floor (120 - 180 million years).   These colorful patterns were mapped by measuring the magnetic properties of the ocean floor.  Ocean floor of similar ages also have similar magnetic patterns.  These patterns are called "linear magnetic anomalies" and formed because the Earth's magnetic field flips polarity. When the Earth's magnetic field "flips",  the north-end of a compass needle swings around so that it points south!

You can control this animation by dragging the mouse across the map. When you do this watch:  India collide with Asia,  Australia rift away from Antarctica, and the pattern of sea floor spreading in the Pacific move towards western North America and South America.  Other animations at this website show the evolution of each of these ocean basin in more detail ( see North Atlantic, South Atlantic, and Pacific).

The information show in this animation was originally compiled by researchers at the Paleoceanographic Mapping Project, University of Texas at Austin.  For more information about how these maps are made see the History and Methods pages of this website.

This animation is available on CD-ROM in Quicktime format.   For more information see Teaching Materials. 

This page uses a java applet that displays a VR model. Visit FreedomVR at www.honeylocust.com/vr/ for more information about this applet.


(c) PALEOMAP Project, 2002. Thanks to WebDoGS by Paul Howell for inspiration.