1.Earthquakes1. According to dictionary.reference.com an earthquake is a: Series of vibrations induced in the earth's crust by the abrupt rupture and rebound of rocks in which elastic strain has been slowly accumulating. The earth is made up of tectonic plates these are massive slabs of rock floating on magma ,as the plates move about, they spread apart, collide, or slide past each other, This is the main cause of volcanoes and earthquakes Earthquakes occur in many regions all over the world in some regions they occur more frequently and severely than in others (depending on the location), the main cause of earthquakes is tectonic plates grinding against each other , therefore earthquakes occur more frequently and more severely in these regions , less commonly earthquakes are caused by volcanic activity in this case they either proceed o r ac company eruptions . VolcanoesVolcanoes are formed when plates collide or move away from one another thus they are usually found at the edge of tectonic plates .Volcanoes can also occur in the interior of plates, these volcanoes are commonly known hotspots. MOVEMENT OF TECTONIC PLATES 2.Tsunamis can be formed by : Underwater earthquake s Underwater earthquakes are the most common cause of tsunami’s .If an underwater earthquake is large enough, significant movements will be made by the ocean floor, pushing up the ocean water upward causing a large ripple that begins to travel through the ocean at a speed of 600miles/h. because the ocean is so deep, the wave is not limited by space resulting in plenty of room to move around, as it gets nearer to the shore the wave size increases in hei ght as the water becomes shallower . Eventually the wave will hit the shore and travel further inland. Volcanoes There are three different ways that volcanoes can cause tsunamis : a land-based volcano can break down and collapse, forcing large amounts of ash and rubble into the water. This sudden change and displacement of the water column transfers to kinetic energy (movement energy) and results in waves. More debris can create a bigger increase in wave size and amount. An offshore or submarine volcanic eruption can create high magnitude lifts on seafloors, which pushes large water columns upwards creating a tsunami. The collapsing of a submarine volcano's slope creates a sudden disturbance in the water resulting in tsunami waves.
1. According to dictionary.reference.com an earthquake is a:Series of vibrations induced in the earth's crust by the abrupt rupture and rebound of rocks in which elastic strainhas been slowly accumulating.The earth is made up of tectonic plates these are massive slabs of rock floating on magma ,as the plates move about,
they spread apart, collide, or slide past each other, This is the main cause of volcanoes and earthquakes
Earthquakes occur in many regions all over the world in some regions they occur more frequently and severely than inothers (depending on the location), the main cause of earthquakes is tectonic plates grinding against each other ,therefore earthquakes occur more frequently and more severely in these regions , less commonly earthquakes arecaused by volcanic activity in this case they either proceed or ac company eruptions .
Volcanoes Volcanoes are formed when plates collide or move away from one another thus they are usually found at the edge oftectonic plates .Volcanoes can also occur in the interior of plates, these volcanoes are commonly known hotspots.
MOVEMENT OF TECTONIC PLATES
2. Tsunamis can be formed by :
Underwater earthquakesUnderwater earthquakes are the most common cause of tsunami’s .If an underwater earthquake is largeenough, significant movements will be made by the ocean floor, pushing up the ocean water upward causinga large ripple that begins to travel through the ocean at a speed of 600miles/h. because the ocean is so deep,the wave is not limited by space resulting in plenty of room to move around, as it gets nearer to the shore thewave size increases in height as the water becomes shallower . Eventually the wave will hit the shore andtravel further inland.
Volcanoes
There are three different ways that volcanoes can cause tsunamis :
a land-based volcano can break down and collapse, forcing large amounts of ash and rubble into the
water. This sudden change and displacement of the water column transfers to kinetic energy(movement energy) and results in waves. More debris can create a bigger increase in wave size andamount.
An offshore or submarine volcanic eruption can create high magnitude lifts on seafloors, whichpushes large water columns upwards creating a tsunami.
The collapsing of a submarine volcano's slope creates a sudden disturbance in the water resultingin tsunami waves.
Despite considerable research efforts by seismologists we still cannot at this stage predict earthquakes to day month
or year, however, for well-understood faults the probability that a segment may rupture during the next few decades
can be estimated. Many phenomena are considered to be possible precursors of earthquakes, and among those
under investigation are seismicity, changes in the ionosphere, various types of electromagnetic indicators including
infrared and radio waves, radon emissions, and even unusual animal behaviour.
Earthquake warning systems
Currently people detect earthquakes by monitoring seismic activity. Earthquake warning systems consist of seismic
motion sensors arranged throughout a region. High speed communications systems and computers collect the sensor
readings and the computers are programmed to detect the likely strength and progression of the seismic event. If a
dangerous event is detected then alarms can be signalled through the region likely to be affected, allowing warnings
before local ground motion of up to and beyond twenty seconds. While short, such warnings would be sufficient to
allow many people to move to safer areas or to take shelter.
4. How volcanoes form
1. Volcanoes most commonly occur where two tectonic plates meet. When two tectonic plates converge they
create a gap/ fissure hot molten rock (magma) then rises up through the fissure .This type of volcano mainly
occurs on the ocean floor where it is difficult to spot.
2. If two tectonic plates converge one plate is forced beneath the other this results in massive amounts of
friction, creating immense heat causing magma to to liquefy and rise up in the form of lava eruptions by these
volcanoes create the most violent and dangerous eruptions as friction greatly increases temperatures causing
gases to expand creating immense amounts of pressure Few volcanoes were formed in this manner, but their
eruptions are very violent and dangerous ones throwing the lava out with great force, and to great heights.
Fortunately only a few volcanoes on earth were formed like this.3. Volcanoes can form in the middle of tectonic plates these are formed by normal tectonic movement where
magma is pushed up little by little until it enters cracks in the rock of the lithosphere .Volcanoes are not always
formed if this is the case ,however, if the overlying rocks are brittle, they give away to allow the magma to flow
out onto the Earth's surface in the form of lava. These volcanoes are commonly known as hotspots ,these are
places that are connected by channels to the mantle of the earth.
Folding Faulting
caused due to horizontal movements caused generally due to vertical movements.Forces move towards a common centre. Forces move away from the common centre.Due to compression, different types of folds areformed.
Due to tension, faults occur along whichdisplacement of rocks take place.
It leads to the formation of anticlines and It leads to the formation of Block Mountains and
synclines. Rift valleys, due to upliftment and subsidence ofland.
They are generally common in sedimentaryrocks, e.g., the Himalayas and the Alps.
They are generally common in Igneous orMetamorphic rocks, e.g., Vosges and Black forestare Block Mountains and the river Rhine flowsthrough the rift valley. In India, river Narmada andTapi flow through a rift valley.
