-”Wegner used the shapes of matching shorelines on different continents as a supporting piece of evidence for continental drift. 3. Describe Earth's magnetic field, including how it has changed through time. -Similar to a simple bar magnet, ends have opposite polarities that cause magnetic objects to align parallel to it’s magnetic field. Poles have wandered from geographical position over the years.
Plate tectonics are the main evidence to support er of the notion of continental drift, as well as the shapes of the continents. Each continent can be positioned to where it once formed a giant land mass known as -
These currents could move continents laterally along the earth’s surface. Paleomagnetism further backs this up, it shows that the positions of magnetic north for 200million year old rock in different continents
The evidence of sea floor spreading was further supported by Vine and Drummond, who studied the magnetic pattern of the sea floor. They found that the Earth’s magnetic field changes over time, because as magma from the mantle rises to the crust it cools but the basalt will align to the field it cools to. It is also found that on either side of mid oceanic ridges there were symmetrical magnetic patterns, so suggesting that the ocean was created at the mid oceanic ridges and as new ocean floor cooled, it pushed the crust away. Both Hess and Vine and Drummond found evidence that is crucial to the explanation of how continental drift happened, and it is very important in the development of geologists understanding, however other people found evidence to support continental drift also. Dan McKenzie went on to further explain sea floor spreading, being able to explain why new crust was made at mid oceanic ridges.
Vine and Mathews were able to demonstrate this revelation through a magnetometer which recorded symmetrical magnetic field across the ridges. Overall, the hypothesis of seafloor spreading was an idea credited to Hess even though he did not provide enough information to prove it. Through Vine and Mathew’s experiment of magnetic reversal they were able to support and provide more evidence to make Hess theory more credible. Today seafloor spreading is active in the The Mid-Atlantic Ridge
Assess the strength of relationship between tectonic processes and major landforms at the Earth’s surface. There is a range of evidence to suggest there is a strong relationship between tectonic processes and major landforms at the Earth’s surface due to, for example, the presence of volcanoes, fold mountains, trenches, and ridges. Tectonic processes include, divergence, which is when plates move away from each other, convergence, when plates move toward each other and collide, Subduction zones, which occur where an oceanic plate meets a continental plate and is pushed underneath, Obduction, which occurs when the continental plate is pushed under the oceanic plate, and collision boundaries, which occur where two continental plates collide and push upwards to form large mountain ranges. However this evidence is weakened by the process of weathering and erosion, due to the presence of the Grand Canyon, one of the Earth’s major landforms. As well as landforms caused by river processes, such as the Bangladesh Delta – which can be seen via satellite - therefore a major landform.
An example of catastrophism is an earthquake. This is an example of catastrophism because it shows a sudden change. Uniformitarianism is the principle that states the geological processes that happened earlier in history can be explained by the geological processes that are happening gradually today. This principle is what people began to consider shaped the Earth. An example of uniformitarianism is when rock wears away and erodes.
Whereas Eyjafjallajokull is in Iceland, an MEDC. The initial eruption of Eyjafjallajokull lasted from 20th March- 23rd June, however the eruption was declared officially over in October 2010. It is located on a spreading ridge, where convection currents are driving apart the North American plate (moving west) and the Eurasian plate (moving east) along a divergent plate boundary. This is creating the Mid Atlantic ridge, along which the age of the rocks either side of the ridge and the palaeomagnetism have been used as evidence of the plate tectonics theory. Both eruptions caused disruption to aviation, particularly Eyjafjallajokull which was a relatively small eruption.
The lithosphere is divided into 7 major plates, including the North-American plate, and several minor plates. Between these plates are three different types of plate boundaries: constructive, destructive and conservative. Earthquakes can occur at all three when pressure builds up and is released in one sudden movement. The Earth’s plates move due to convection currents within the mantle in the Earth’s asthenosphere. As heat rises and cools it forces the plates in different directions; either sliding past one another, away or towards each other.
An earthquake’s depth can be considered shallow (less than 70km), intermediate (between 70km and 300km), or deep (300km to 700km) (Earthquake, 2014). Plate tectonics are responsible for the sudden release of energy in the Earth’s crust. There are three types, divergent, convergent, and transform.