2) The idea of continental drift was brought to life by a 32-year old German meteorologist named Alfred Lothar Wegener. He came up with the idea in 1912. Wegener stated that around 200-million years ago the supercontinent Pangaea began to break apart into what we know of the world today. Alexander Du Toit, Professor of Geology at Witwatersrand University who was one of Wegener's supporters gave the idea that Pangaea first broke into two large continental landmasses, Laurasia in the northern hemisphere and Gondwanaland in the southern hemisphere. Then they continued to break into the smaller continents of our present day. This idea wasn't accepted mainly because Wegener was a meteorologist and not a geologist, also because it seemed very unlikely and he didn't have enough evidence.
3) Alfred Wegener was also the founder of the Plate Tectonic Theory. He proposed this theory with facts in the 1960s. The shapes of many continents look like they are separated pieces of a jig-saw puzzle. The shape of the east coast of North and South America is relative to the shape of the west coast of Africa and Europe. Many fossil comparisons along the edges of continents that look like they fit together suggest species similarities that would only make sense if the two continents were joined at some point in the past. There are ridges, such as the Mid-Atlantic Ridge where plates are separating that are produced by lava welling up from between the plates as they pull apart. There are mountain ranges being formed where plates are pushing against each other.
4) The hotspot theory was created by Canadian geophysicist J. Tuzo Wilson. The theory was formed in 1963. Wilson proposed that small, long lasting, exceptionally hot areas of magma, called hotspots, exist under the Earth's surface. These heat centers create thermally active mantle plumes, which in turn sustain volcanism. This "mid-plate" volcanism builds peaks that rise from relatively featureless sea floor, initially as seamounts as later as fully-fledged volcanic islands. In Hawaii for example, heat from this hotspot produced a persistent source of magma by partly melting the overriding Pacific Plate. The magma, which is lighter than the surrounding solid rock, then rises through the mantle and crust to erupt onto the seafloor, forming and active seamount. Over time, eruptions cause the seamount to grow until it emerges above sea level to form an island volcano. According to Wilson's theory, the Hawaiian volcanoes should be progressively older and increasingly eroded the further they are from the hotspot. As one island volcano becomes extinct, another develops over the hotspot, and the cycle is repeated. This process of volcano growth and death, over many millions of years, has left a long trail of volcanic islands and seamounts across the Pacific Ocean floor. The theory created by Wilson is widely accepted as valid.
4) The hotspot theory was created by Canadian geophysicist J. Tuzo Wilson. The theory was formed in 1963. Wilson proposed that small, long lasting, exceptionally hot areas of magma, called hotspots, exist under the Earth's surface. These heat centers create thermally active mantle plumes, which in turn sustain volcanism. This "mid-plate" volcanism builds peaks that rise from relatively featureless sea floor, initially as seamounts as later as fully-fledged volcanic islands. In Hawaii for example, heat from this hotspot produced a persistent source of magma by partly melting the overriding Pacific Plate. The magma, which is lighter than the surrounding solid rock, then rises through the mantle and crust to erupt onto the seafloor, forming and active seamount. Over time, eruptions cause the seamount to grow until it emerges above sea level to form an island volcano. According to Wilson's theory, the Hawaiian volcanoes should be progressively older and increasingly eroded the further they are from the hotspot. As one island volcano becomes extinct, another develops over the hotspot, and the cycle is repeated. This process of volcano growth and death, over many millions of years, has left a long trail of volcanic islands and seamounts across the Pacific Ocean floor. The theory created by Wilson is widely accepted as valid.
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