Tectonic Plates Flashcards
(7 cards)
What are plate tectonics?
Plate tectonics is a theory explaining the structure of the earth’s crust and many associated phenomena as resulting from the interaction of rigid lithospheric plates which move slowly over the underlying mantle.
Explain how evidence supports Plate Tectonic Theory
One piece of evidence is the jigsaw fit. The jigsaw fit is when all the continents use to be one whole piece of land instead of plate boundaries such as the African plate and the Eurasian plate. This land was called Pangea. The man who came up with this theory was called Alfred Wegener (he was a german geologist).
Another piece of evidence is the convection currents. The convection currents were found to be slow yet with extremely powerful movements of volcanic rock in the mantle. The magma in the mantle is heated to around 5,500*C and rises to the crust where they cool and descend only to be heated . This was powerful enough to move the Earth’s plates.
Explain why earthquakes and volcanoes are found along plate boundaries
At diverging plate boundaries, earthquakes occur as the plates pull away from each other. Volcanoes also form as magma rises upward from the underlying mantle along the gap between the two plates. We almost never see these volcanoes, because most of them are located on the sea floor.
Explain how earthquakes and volcanoes occur at Constructive plate boundaries
Although often not as violent as those on destructive plate boundaries, volcanoes and earthquakes do occur on constructive plate boundaries. They also cause mid-ocean ridges to form. This forms a mid-ocean ridge. Volcanoes can also form here, along the edges of the plate boundary, due to the rising magma.
Explain the effects of the Montserrat volcano (including facts)
There were many facts but one which is the worst is a statement stating ‘Over 20 villages and 2/3rds of the buildings were destroyed’. This statements means that many homes were lost and more people were made homeless. When it states ‘2/3rds of the buildings were destroyed’ this means that many jobs were lost meaning people had less money so they could survived and not starve to death of die to dehydration.
Explain why human and physical factors caused the Haiti earthquake to be so destructive
In my opinion the worst effect of the Haitian earthquake was the statement of ‘Dead bodies were trapped under buildings meaning diseases were spread’. This is very bad because more of the population died to the diseases and not to the earthquake. This is a human factor to why there were so devastating effects because the buildings safety was not good.
In my opinion another bad effect is the statement of ‘There were frequent power cuts which produced difficulties for the hospital to help people’. This is a really bad effects because since there were power cuts the hospital couldn’t really use their equipment and lives were lost.
Explain the cause of a Tsunami?
A tsunami is a series of large waves generated by an abrupt movement on the ocean floor that can result from an earthquake, an underwater landslide, a volcanic eruption or - very rarely - a large meteorite strike. However, powerful undersea earthquakes are responsible for most tsunamis.
