Drifting ice delayed the expedition and the Arctic weather proved a great hardship. Wegener, your theory of the Pangea was a thought that all the continents were one landmass before the many years of plate tectonics shifting. He helped to plan the U. An American Sailor named Harry Hess had a scanner called a sonar which discovered jagged images from the bottom of the ocean. In this discussion, you are to compose a personal letter to the German scientist, Alfred Wegener, who proposed the theory of continental drift. Maybe helium has some anti-gravity properties! Or would he suffer the same criticisms that Wegener had endured? New crustal plate is formed at the mid-ocean ridges and old crustal plate is destroyed at deep ocean trenches. Alfred Wegener produced evidence in 1912 that the continents are in motion, but because he could not explain what forces could move them, geologists rejected his ideas.
What Hess discovered was a big surprise. He died in 1930 of a heart failure because he smoked. They glide over the mantle. The established reputation of many of his detractors probably gave more weight to their criticisms than was merited. Wegener, I feel like your theory on plate tectonics has been proven correct. Without the magma from the plume to fuel the volcano it becomes dormant.
He saw that mountain ranges formed as narrow bands at the edge of continents. In 1953, scientists discovered that a prominent valley, called the Great Global Rift, ran down the center of these ridges. Hess held the position until his death in 1969 and played a key role in the planning of the Apollo moon landings. Retrieved January 30, 2009, from Leitch, A. When igneous rocks like basalt crystallize, the iron atoms in them align with the magnetic field of the earth.
Or the plates may move sideways, grinding against each other. Iceland is split down the middle, belonging to two different plates. First, fossils were found on parts of the world that would not have had the correct environment conditions. Wegener experimented with kites and balloons, and with his brother Kurt set a world record in an international balloon contest, flying 52 hours straight. I hope this helps you with further research. Most of Africa is pushing northward toward Europe and will eventually squeeze out the Mediterranean Sea and cause high mountains to emerge along the whole southern coast of Europe.
Alfred, i follow what your saying about the continents that were once together. The plates are like a hard, rigid shell. This suggested that the formations were once whole and later divided. And if you dont believe that evidence then just look at the way the contients are formed. Hess explained that new crust was created at the Great Global Rift and was pushed under the continental crust about 300 million years later where it would melt and turn into magma. Though he served in World War I and was wounded twice, he published his ideas in 1915. Yet the surface of the Earth is not fixed, but rather broken up like a jigsaw puzzle into enormous plates that move.
Sure enough, surveys of either side of the Mid-Atlantic Ridge showed a symmetrical pattern of alternating polarity stripes. After the war, he remained in the , rising to the rank of. Later studies showed that the age of the ocean floor increases with distance from the ridge crests, and seismic studies confirmed that the oceanic crust was indeed sinking into the trenches. Pockets of hot liquid magma ooze up along extensive mountain ridges deep under the water, one running roughly north-south in the mid-Atlantic and another in the mid-Pacific. The first one is easy. By 1910 he had noticed on a world map that the east coast of South America fits exactly against the west coat of Africa, as if they had once been joined. You stated that studys in diffrent contients have the same fossil.
Hess discovered features on the floor of the ocean that appeared to be mountains with the tops flattened. We can surely use that in part of our research to keep proving that they were once one. In November 1930 Wegener led several dogsled teams carrying supplies to his colleagues at the isolated inland station, which was under-provisioned. Hess possessed two valuable skills: careful attention to detail and the ability to form sweeping hypotheses. He had a substantial amount of evidence that made sense; nonetheless, without a driving force behind it, the scientific community simply discredited his entire idea. Dear Olivia, I'm afraid your letter did not tell me anything about how this discovery relates to me, it seems as though you were just talking to yourself. © 2000 American Museum of Natural History.
For a quick example, pretend for a few moments that you don't know why a balloon filled with helium will float. It also brought the thought of plate tectonics having to do with the creation of mountains, islands, and trenches. It was the first expedition organized specifically to gather data on a wide range of ocean features, including ocean temperatures seawater chemistry, currents, marine life, and the geology of the seafloor. In your letter to Alfred address the following items: a. He soon developed a system for estimating the daily positions of German U-boats in the North Atlantic, and requested duty aboard a decoy vessel in order to test the program. This unusual combination produced groundbreaking work on a number of subjects, including the origin of ocean basins and island arcs, mountain building, and the movement of continents.