Y9 Assessment Au2 Flashcards
(11 cards)
Explain how evidence supports Plate Tectonic Theory
The jig saw fit- looks like all continents were together
Convectional Currents- convection currents move continents very slowly.
Study of fossils- similar ones found on different continents
Geological patterns- mountains in Northern Europe and North America are the exact same type and age
When and who made the Plate Tectonic Theory
In 1912, a Geologist called Alfred Wegener
Convection currents for plate tectonic theory
The magma is heated in the mantle and rises to the crust where they cool and sink only to be heated again. This creates movement
Fossils for tectonic theory
Similar fossils are found on different continents and these fossils are from animals who could not cross the ocean
Explain why earthquakes and volcanoes are found along plate boundaries
Inside a boundary things move so the boundarybwill also move
Where are most earthquakes and volcanoes formed around the world
The pattern is that almost all of them are on plate and I know this because using my own knowledge there have only been 11 earthquakes/volcanoes that isn’t on a plate boundary
Explain how earthquakes and volcanoes occur at Convergent/ plate boundaries
Two plates move towards eachother because of convection currents. Huge amounts of pressure occurs at the subductive zone. The plates get jammed together, causing an earthquake and the friction causes melting in the mantle. Eventually the pressure rises and a violent eruption happens
Explain how earthqaukes and volcanoes occur at Divergent plate boundaries
Convection currents from the mantle drive the movement of tectonic plates. When magma rises it feeds volcanoes. The mantle sticks to the oceanic crust and moves it in the opposite direction of the other half. As it moves so does volcanoes. When volcanoes get far enough they don’t get fed and they slowly fade away
Explain the effects of the Montserrat volcano (with facts)
Large areas were destroyed (their capital) and volcanic ash was still in the air. They also had no clue that it would errupt or what the effects would be. It made them lose a lot of money from tourism and most of their island. The population also went down by more than 75%
Explain why the Haiti erruption was bad because of humans and nature
Humans made it bad because of the massive population. But nature was bad because it wasn’t developed. They had more than 500 people per km2 where the epicentre was and they have a 156/182 ranking in development. Low quality greater population more damage. Less people would get hurt and less buildings collapse and more damage because of low quality things- low development
Explain the cause of a Tsunami
On a plate boundary between the two different plate areas subduction occurs and tension builds over many years. The dense plate is being subducted by the less dense plate. An earthquake occurs and water is displaced 30km3 upwards at the epicentre. In deep water waves are low and fast- as they approach shallow water they slow, grow taller and converge together. Waves spread out across the ocean. 20-30 m waves break onto the coast
