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Greenland MapAlfred Wegener travels to Greenland with the Danish Expedition to study polar air mass circulation.
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"Doesn't the east coast of South America fit exactly against the west coast of Africa, as if they had once been joined?" wrote Wegener to his future wife.
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Wegener startles those present by dimissing the idea of sunken land bridges and proposes that drifting continents and widening seas are responsible for the Earth's geography. According to Wegener, ' the forces that displace continents are the same as those that produce great fold-mountain ranges. Continental drift, faults and compressions, earthquakes, volcanicity, [ocean] transgression cycles and [apparent] polar wandering are undoubtedly connected on a grand scale'.
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Wegener's theory is published but goes unnoticed outside of Germany. His theory is supported by evidence of land features, coal beds, glacial deposits and Glossopteris, Lystrosaurus and Mesosaurus fossils. In years to follow, he supported his theory with new geologic evidence and republished each time. His theory was almost universally met with outright hostility by the scientific community as he had no method of supporting how the continents could move.
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Wegener returns to Greenland to cover many miles of harsh, cold terrain in order to systematically study the great ice cap and its climate. The picture is with an Inuit guide.
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After celebrating Alfred's 50th birthday, Wegener and two others journey to the coast to get more supplies. At some point in the trek, all three die of cold and lack of supplies.
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Six months after his research team last saw him, Wegener's body is found sewn inside a sleeping bag. They believe he died in his sleep of a heart attack.
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American naval officer and geologist, Harry Hess, studies the ocean floor and finds strange mountains he calls 'guyots' which are later called mid-ocean ridges. He suggests that sea-floor spreading at mid-ocean ridges adds new material to the ocean floor all the time.
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In the 1950s, the field of paleomagnetism found that the ocean floor has a magnetic pattern. Earth's north and south magnetic poles reversed themselves througout history, so rocks formed at times of different magnetic poles have a distinct pattern along the mid-ocean ridge.
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Rock samples from the ocean floor were gathered by the Glomar Challenger, a drilling ship built in 1968. Scientists analyzed the samples and found the age of the rocks. The youngest rocks were always in the center of the ridges and became progressively older farther away from the ridges.
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Alvin was a three-person submersible built to take scientists down to the ocean floor.
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Locations of earthquake epicenters worldwide are supporting evidence of the theory of plate tectonics which states that pieces of Earth's lithosphere are in slow, constant motion, driven by convection currents in the mantle. Forces within the Earth greatly impact humans living along plate boundaries, such as the Ring of Fire.
