Plates And Volcanoes Flashcards
(25 cards)
What do plate tectonics refer to?
The theory that the earths surface is broken into large pieces called tectonic plates. These plates move due to the movement of energy in he earth’s interior.
What is the evidence of plate tectonics?
Similar plant species
Climatology
Same types of rocks (in mountains)
Continental drift
Jigsaw theory
Fossils of same animal all over the world
Where are the different layers of the earth positioned?
Crust - thin outer layer
Mantle - first section
Outer core - second section
Inner core - third or middle section
What is some information about the crust?
. The thin, outer layer of the earth
. Made of solid rock
. The layer we live on
. It is composed of several tectonic plates
What is some information about the mantle?
. It can be up to 2,900 km wide
. The upper part is hard rock, but the lower part has begun to melt
. Part of it is made from semi - molten rock called magma
What is some information about the outer core?
. It surrounds the very centre of the earth
. This liquid layer is made from iron and nickel and is extremely hot
What is some information about the inner core?
. It is at the centre of the earth
. It is extremely hot with temperatures up to 5,500 C
. There is lots of heat energy (power) like the engine in a car
. This solid layer is made from iron and nickel
What are some aspects of the continental plate margin?
. Thick
. Old
. Permanent
. Floats
. Less dense
What are some aspects of the oceanic plate margin?
. Thin
. Young
. Re - made
. Sinks
. Dense
What are the directions the convergent, divergent and transform plates go in?
Convergent come together (destructive)
Divergent divert away (constructive)
Transform slide (conservative)
What are some key words describing the anatomy of a volcano?
Magma chamber
Vent
Crater
Secondary vent
Lava
Topography
Viscosity
Cloud
Pyroclastic flow
Tephra (or volcanic bombe)
What are shield volcanoes constructive or destructive?
Constructive
Are composite volcanoes constructive or destructive?
Destructive
What are some elements of composite volcanoes?
. They are made of alternative layers of ash and lava
. They are found at destructive margins. The melted oceanic plate rises to the surface as magma.
. They erupt infrequently but very violently releasing ash, lava and rock.
. They am Mount Fuji or Mount Vesuvius.
. They are tall with steep sides.
. They have sticky, acidic lava.
What are some elements of shield volcanoes?
. Thry have a wide base and gently - sloping sides.
. They are found at constructive plate margins. As two plates move apart magma rises.
. Lava flows more easily as it is hotter, therefore travelling long distances before cooling.
. They erupt frequently, but not very violently.
. They have runny, easy flowing lava.
. They are Mauna Loa in Hawaii or Santa Barbra in the Azores.
What is an earthquake?
The sudden release of strain energy in the earths crust, resulting in waves of shaking that radiate outwards from the earthquake source. The point in the crust where the energy is released is called the focus. The point on the earths surface above the focus is called the epicentre.
What are earthquakes measured using?
The Richter scale/moment magnitude scale - a measure of the energy released.
What is a mercali scale?
A measure of the damage caused by an earthquake.
What is the Richter scale?
A 10 logarithmic scale measured on a seismometer.
What are the two main advantages and disadvantages of the Richter scale?
They are objective but with more choices.
What are the two main advantages and disadvantages of the mercali scale?
They are subjective but are limited and more people would disagree.
What plates were involved in Japans tsunami?
The pacific and Eurasian plate. It occurred in 2011.
What causes tsunamis?
2 tectonic plates that are moving towards each other. The plates move which also causes an earthquake and volcanic landslides. Meteorites can also cause a tsunami.
What are the 3p’s and what do they mean?
. Protection - earthquake proof buildings and protect family and friends.
Preparation - drills (drop,cover,hold) through websites and education - emergency pack.
. Prediction - we cannot predict an earthquake but we can predict where they occur e.g. plate margin
