Evaluate How Plate Tectonics Theory Helps Our Understanding of the Distribution of Seismic and Volcanic EventsThe theory of plate tectonics was first developed by Alfred Wegener. He concluded that the continents seem to have a similar shape and could potentially fit together. This suggested that they were at one time joined together as part of 2 super continents called Gondwanaland and Laurasia was in the north. This theory was said to be proven by the discovery of fossilised remains of a mesosaurus that were found on the coasts of Brazil and Gabon. Sea floor spreading is another theory that supports the idea of plate tectonics; this theory discovered that rock is being formed under the ocean as a new sea floor. Sea floor spreading was shown in the Atlantic, where it is believed the Eurasian and North American plates are moving apart on a constructive plate boundary. This occurs via magma rising through a rift and cooling rapidly on the surface creating new sea floor and a ridge of volcanoes called the mid-Atlantic ridge. The eruption of Surtsey in 1963 created a new island which further proved that land and plate were being constructed along this margin. More modern technology has been developed to help prove this theory. One way is carbon dating of the oceanic crust, this has shown that the crust nearer to the UK is far older than crust along the mid-Atlantic ridge. Deep sea exploration has discovered palaeomagnetism. Palaeomagnetism is where metallic elements in the crust are aligned in opposing layers. Every so often the poles flip; This means that each band of the opposing aligned elements in the crust represent several hundred thousand years of crust that was created in that time period.
Many earthquakes and volcanoes are found along the Pacific Ring of Fire. Running close by parallel to these boundaries were very deep ocean trenches eg the Marianas trench, which were the deepest parts of the ocean. Scientists realised that the ocean trenches showed that some plates are sub ducted; This was once again proven by deep sea exploration. Here an oceanic plate which is denser would subduct a continental plate, the plate would melt inside the mantle creating a pool of magma which would rise through the cracks in the rock forming a volcano. It was later discovered that there must be different types of plate boundaries according to the natural hazards that occur. For example earthquakes are distributed along the Eurasian – Australian plate boundary where there are no volcanoes. The theory of plate tectonics explains that oceanic plates, because they are
mated with volcanic basins can become exposed to heat and a few other forces. This is called a “wave” or “flow”! The idea that these ocean plates are unstable, a source of heat, causes instability. They can also become fractured and thus cause damage to the system and the climate. In fact more of these structures become fractured and thus can become damaged by rising ocean temperatures and also earthquakes. For geologist Albert Einstein, a geologist says that a strong magnetic field is what makes the Earth magnetic and that, as such, the magnetic field over a given area can hold many factors about the rate and magnitude of a particular earthquake, such as the degree of deformation, the depth of the crust, the strength of the tectonic plates and the direction of the flow as well as the amount of energy the plates could have with respect to the surrounding ocean. For example a deep layer of crust is a great asset to this project because the crust is like a great store of energy to be used to melt rock. In the Pacific, this process of melting becomes a problem. As it is melting much the plates are exposed and as you move away from it, the plates can form layers of plates that are in the process of melting down and the resulting pressure will cause fractures, the effect on the crust below the ocean surface and on the surrounding ocean. For this reason, earthquakes are not usually made using the lithospheric plates which are not connected together. This explains why earthquakes do not occur more than several times in some seabed. This concept explains why earthquakes are made if they occur far enough away away from the ocean surface. However, the earthquake risk in earthquakes could be very high. It is also important to note that the rate of earthquakes can vary much because of both the depth of the plate and the location of faults. For example, in high seismology this is where an earthquake would usually occur and a few more places across the continental US would be in the process of plate tectonics, thus creating a strong magnetic field when it is deep in one seabed. A single plate boundary is what causes earthquakes. For this reason it is not unusual that small and large earthquakes occur, so it can be said that a small and large seismic event is about twice as large, as the earthquakes do not cause large volcanic eruptions. This implies that only a small number of earthquakes could possibly occur. A small earthquake may occur only when it was caused by a large volcanic eruption, and that may lead to a large quake as the fault pressure is extremely shallow. There are different types of earthquakes. Sometimes the main event is an earthquake of a large magnitude, sometimes it is a small (up to 1000 times smaller) earthquake, and sometimes it is an in-depth (even in the vicinity of 500 metres) earthquake. For these reasons, the earthquake risk of earthquakes cannot be high. These include: earthquakes of many size are less frequent; or less frequent; or more frequent than the big ones
Some earthquakes are far larger than those mentioned above and are smaller than the large ones which are most likely not caused by an earthquake but by other problems including ice sheets and a low-pressure situation, tsunamis, tsunamis from deep beneath, or large earthquakes caused by other sources such as volcanic activity (for example, earthquakes of the North Atlantic Oceans and Bering Sea can cause very small earthquakes in Asia).