Plate Boundaries
As each tectonic plate moves, a variety of events occurs along its plate boundary. One part of the plate moves away from the neighbouring plates (diverges), and another part slides along a transform fault line or is subducted below the neighbouring (convergent) plate.
There are four types of plate boundaries -
1. Divergent boundaries - where new crust is generates as the plates pull away from each other.
2. Convergent boundaries - where crust is destroyed as one plate dives under another.
3. Transform boundaries - where crust is neither produced nor destroyed as the plates slide horizonatlly past each other.
4. Plate boundary zones - broad belts in which boundaries are not well defined the effects of plate interaction are unclear.
There are three types of fault lines -
1. Thrust (reverse) - where the two blocks move towards each other so one is thrust higher.
2. Strike-slip - where the two blocks slide in opposite directions (horizontally), resulting in sideways movement of roads and rail lines.
3. Normal - where the two blocks of Earth are initially pulled away from each other, allowing one block to slip down and the other to slip upwards.
As each tectonic plate moves, a variety of events occurs along its plate boundary. One part of the plate moves away from the neighbouring plates (diverges), and another part slides along a transform fault line or is subducted below the neighbouring (convergent) plate.
There are four types of plate boundaries -
1. Divergent boundaries - where new crust is generates as the plates pull away from each other.
2. Convergent boundaries - where crust is destroyed as one plate dives under another.
3. Transform boundaries - where crust is neither produced nor destroyed as the plates slide horizonatlly past each other.
4. Plate boundary zones - broad belts in which boundaries are not well defined the effects of plate interaction are unclear.
There are three types of fault lines -
1. Thrust (reverse) - where the two blocks move towards each other so one is thrust higher.
2. Strike-slip - where the two blocks slide in opposite directions (horizontally), resulting in sideways movement of roads and rail lines.
3. Normal - where the two blocks of Earth are initially pulled away from each other, allowing one block to slip down and the other to slip upwards.
Geological Events
Tectonic plates become stressed by the pressure of colliding neighbouring plates or by movement of the mantle below it. Energy is released by this sudden and very violent movement of the crust. This energy is released in an earthquake.
Earthquakes
These disturbances occur when energy is generated by rocks breaking suddenly within the Earth or if there is an explosion. This energy travels as seismic waves either through the Earth (body waves) or across the survce. Body waves are either transvers (S Wave) or longitudinal (P Wave). Other S waves you might be familiar with are sea waves. Sound or vibrations are examples of P waves. S and P waves travel through the Earth at different speeds. P waves are usually the first waves to be recorded by a seismograph.
Earthquakes are caused when energy is released at a point (focal point) between two crustal regions moveing agains, past or over one another (fault lines). Energy released in an earthquake travels as seismic waves, which cause the ground to move as they pass through it. The point directly above the focual point on the surface of the Earth is called the epicentre.
Tectonic plates become stressed by the pressure of colliding neighbouring plates or by movement of the mantle below it. Energy is released by this sudden and very violent movement of the crust. This energy is released in an earthquake.
Earthquakes
These disturbances occur when energy is generated by rocks breaking suddenly within the Earth or if there is an explosion. This energy travels as seismic waves either through the Earth (body waves) or across the survce. Body waves are either transvers (S Wave) or longitudinal (P Wave). Other S waves you might be familiar with are sea waves. Sound or vibrations are examples of P waves. S and P waves travel through the Earth at different speeds. P waves are usually the first waves to be recorded by a seismograph.
Earthquakes are caused when energy is released at a point (focal point) between two crustal regions moveing agains, past or over one another (fault lines). Energy released in an earthquake travels as seismic waves, which cause the ground to move as they pass through it. The point directly above the focual point on the surface of the Earth is called the epicentre.
Plate boundaries have more seismic activity than regions located in the middle of tectonic plates. Earthquakes do occur in the middle of tectonic plates in these regions, but they are very small and often go unnoticed.
As seen in the map below, Australia lies in the middle of the Indian-Australian tectonic plate well away from its boundaries. This location provides a very stable region. Compare this to New Zealand, Japan and Indonesia, all of which lie on or are very close to plate boundaries. These countries experience regular seismic and volcanic activity.
As seen in the map below, Australia lies in the middle of the Indian-Australian tectonic plate well away from its boundaries. This location provides a very stable region. Compare this to New Zealand, Japan and Indonesia, all of which lie on or are very close to plate boundaries. These countries experience regular seismic and volcanic activity.
Volcanic activity can also produce earthquakes. These are usually less violent than those generated when fault lines rupture but cataclysmic eruptions can generate destructive seismic activity.
TASK 1
Choose an earthquake that has happened in the past. Research the strength of the quake and what plates, fault lines, were involved. Find out what life was like after the earthquake. How long did it take for the area to recover. Define what you mean by 'becover'. What effects do earthquakes have, other than the physical damange?
Tsunamis
Tsunamis are waves usually generated by the sudden movement of the seafloor or, on rare occasions, by huge landslides or meteorite impacts into the ocean.
Question 1:
Where does the name Tsumani originate from? What does it mean?
Tsunamis are not the same as tidal waves, which are generated by tidal forces and which we can see every day.
Tsunamis, like all waves, have a crest, a trough, a wavelength (distance between successive crests), an amplitude, a fequency and a velocity.
Choose an earthquake that has happened in the past. Research the strength of the quake and what plates, fault lines, were involved. Find out what life was like after the earthquake. How long did it take for the area to recover. Define what you mean by 'becover'. What effects do earthquakes have, other than the physical damange?
Tsunamis
Tsunamis are waves usually generated by the sudden movement of the seafloor or, on rare occasions, by huge landslides or meteorite impacts into the ocean.
Question 1:
Where does the name Tsumani originate from? What does it mean?
Tsunamis are not the same as tidal waves, which are generated by tidal forces and which we can see every day.
Tsunamis, like all waves, have a crest, a trough, a wavelength (distance between successive crests), an amplitude, a fequency and a velocity.
The wavelength of a tsunami is extremely long. Normal ocean waves are measured in metres. A tsunami wavelength is measured in kilometres. The speed of a tsunami can be up to 950km/h compared with ocean waves of 90km/h.
As tsunami reaches the coast, ocean depth decreases, the wave slows down and its height increases.
TASK 2:
On 26 December 2006, a tsunami off Sumatra, Indonesia, killed an estimated 230 210 people. Find 5 other facts about this disaster.
Volcanoes
Volcanoes are breaks or ruptures in the Earth's crust, which allow magma to escape its confines deep within the upper mantle. Magma is extremely hot rock that contains gases. As the magma reaches the surface and the presssure decreases, the gases are released. As the magma reaches the surface it become lava.
As tsunami reaches the coast, ocean depth decreases, the wave slows down and its height increases.
TASK 2:
On 26 December 2006, a tsunami off Sumatra, Indonesia, killed an estimated 230 210 people. Find 5 other facts about this disaster.
Volcanoes
Volcanoes are breaks or ruptures in the Earth's crust, which allow magma to escape its confines deep within the upper mantle. Magma is extremely hot rock that contains gases. As the magma reaches the surface and the presssure decreases, the gases are released. As the magma reaches the surface it become lava.
Lava is classified into four types depending on its composition, mainly by how much silicon dioxide, SiO2 it contains.
TASK 3:
Complete the table below:
TASK 3:
Complete the table below:
TASK 4:
Compare and contrast the effects of geological events. Consider the physical damage caused, the frequency of the event occuring, the recovery period and the long term damage the event can cause.
Present your findings in a Persuasive Essay - If I had to experience a earthquake, tsunami or volcano eruption I would prefer to experience ..... because....
Compare and contrast the effects of geological events. Consider the physical damage caused, the frequency of the event occuring, the recovery period and the long term damage the event can cause.
Present your findings in a Persuasive Essay - If I had to experience a earthquake, tsunami or volcano eruption I would prefer to experience ..... because....