What did Harry Hess propose in 1963? He proposed that molten rock erupts from the Earth's interior along mid-oceanic ridges, creating new seafloor. What magnetic field, polarity evidence supports the theory of plate tectonics? -the earth's magnetic field was especially strong over the oceanic ridges that were made up of iron rich materials -the magnetic field formed a zebra-striped
5. Why is the pattern of alternating reversals of the Earth's magnetic field as recorded in the sea floor rocks such an important piece of evidence for advancing plate tectonics? -It changes the direction of where some materials move so it might help plate tectonics move one way or the other. 6. Describe sea floor spreading and explain why it is an important piece of evidence for advancing plate tectonics.
Which makes them significant to economies. The Pacific ocean, because the plates plunge beneath the mantle in this area. Hydrogenous sediment is formed when minerals crystallize in ocean water due to many types of chemical reactions. They come from trenches and shelves. They are used for making concrete.
Lava and pyroclastic flows are both examples of primary volcanic hazards, whilst lahars landslides are secondary. Seismic hazards are initially ground movement and landslides, and in some cases can be preceded by tsunamis. The soonest discovery made after Wegner’s proposal was Harry Hess’ finding of a concept known as Sea Floor Spreading in 1950. This occurs mainly at constructive plate margins in which magma rises through the newly created space caused by the spreading
Seismic and volcanic events are major pieces of evidence towards proving that plate tectonic theory is valid. Discuss the extent to which you agree with this view. (40) The plate tectonics is a theory about how the earth is split up into large segments that we call tectonic plates. These plates are the only consist of the top layer of the earth structure called the lithosphere; they float about on the Asthenosphere by the convection currents in the magma. Alfred Wegner was the theorist behind the discovery of tectonic plates back at the start of the 19th century.
It allows us to understand how sedimentary rocks, metamorphic rocks, and Igneous Rocks use one another to not only form the Rock Cycle, but also other processes that are important to our planet. The rock cycle beings with hot magma, deep below the earth’s surface. Once the magma dries, crystallization occurs, and results in igneous rocks. Over time weathering occurs to the igneous rocks. Over time weathering takes over the igneous rocks.
In this short paper, the change in the ocean chemistry is explored. Scientists have talked much about global warming and climate change, phenomena brought by the increase in greenhouse gases in the atmosphere. There is no other greenhouse gas that influences climate change more than carbon dioxide (Raven et al., 2005). Acidification, which brings changes in the chemistry of the ocean is another problem brought by carbon dioxide. Carbon dioxide does not only cause problems in the atmosphere but also in the ocean.
They changed because the molecules of hydrogen and helium were moving so fast that they eventually escaped the Earth. 14. Explain how the greenhouse effect works and how it relates to global warming. The greenhouse effect is when radiation at visible wavelengths passes freely through the atmosphere and is absorbed at the ground. The ground heats up and emits infrared radiation.
As well as landforms caused by river processes, such as the Bangladesh Delta – which can be seen via satellite - therefore a major landform. One major piece of evidence in support of a strong relationship between tectonic processes and major landforms on the Earth’s surface is the Mid Atlantic Ridge. The Mid-Atlantic Ridge is an underwater mountain range caused by a diverging tectonic plate along a constructive plate boundary located along the floor of the Atlantic Ocean. The MAR is the longest mountain range in the world, therefore is definitely one of the Earth’s major landforms, and is caused by tectonic activity therefore the relationship between tectonic activity and major landforms reinforced by this evidence. In the North Atlantic, the MAR separates the Eurasian and North American Plates, whereas in the South Atlantic it separates the African and South American Plates, this evidence emphasises the size of the MAR and backs up
To what extent can the theory of plate tectonics explain global distribution of seismic and volcanic activity? The global seismic and volcanic activity is concentrated along the margins of the earth’s plates, which are broken pieces of the crust and are moved by convection currents that are caused by heat rising and falling inside the mantle generated by radioactive decay in the core. This movement of the plates and the Earth’s inner activity is called plate tectonics and can cause seismic and volcanic activity. However, earthquakes and volcanoes also occur within the plates rather than their edges, an example of which is the Hawaiian volcanoes that occur above a stationary hot spot beneath the Pacific plate. In the late 1960s the theory of plate tectonics was developed by Alfred Wegener and provides an explanation for the Earths tectonic behaviour, particularly the global distribution of mountain building, earthquake activity, and volcanism in a series of linear belts.