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SHHS Edexcel Year 12 Geography > Tectonics > Flashcards

Flashcards in Tectonics Deck (124)
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What is a hazard ?

A perceived natural or geophysical event that has the potential to threaten both life and property.


When was the Bam (Southern Iran) earthquake?

January 2003 at 05:26 AM


What is an oceanic fracture zone (OFZ)?

A belt of activity through the oceans along the mid-ocean ridges, coming ashore in Africa, the red sea, the dead sea rift and California.


What is the continental fracture zone (CFZ)?

A belt of activity following the mountain ranges from Spain, via the Alps, to the Middle East, the Himalayas to the East Indies and then circumscribing the Pacific.


What are the three main qualities of a Tsunami?

Long wavelengths, low amplitude and fast velocities


Fact file about the Icelandic Volcano (Eyjafallajallajokul)

-April 15th 2010
-High profile (impacts on the air movement) but a relatively small eruption.
-No direct deaths
-Massive ash plume generated affected much of Europe stretching as far as Italy.


What are earthquakes forecasts currently based on?

They are based on data and evidence gathered through global seismic monitoring networks, as well as from historical records.


State 3 ways vulnerability is different in a developing country.

1. People only have access to limited resources.
2. Government does not prioritise them.
3. They are economically and politically 'on edge'. People rely on government aid despite the impact this may have on families.


How have the natural-hazard trends developed since 1960?

1. Total number of recorded hazards increased
2. Number of deaths decreased in recent times
3. Total number of affected people increased
4. Economic costs increased significantly


Referring to the Swiss Cheese Model, suggest how hazard and disaster risk can be reduced.

1) Reducing the number of holes in each layer (the number of systematic weaknesses)
2)Reducing the size of he holes in each layer.


What is a Subduction Zone?

broad areas where two plates are moving together, the denser oceanic plate descending beneath the continental plate.


What is the Benioff Zone?

The Benioff zone is an area of seismicity corresponding with the slab being thrust downwards in the subduction zone.


Which plate boundary generates the largest most damaging earthquakes?

Convergent (two plates moving together).


What are the characteristics of a tectonic mega-disaster?

1. Large-scale in either spatial terms or economic and human impacts
2. Difficult to manage impacts
3. International support needed both immediately and during long-term recovery


What are tectonic mega-events often classified as?

HILP - high impact, low probability


What is Paleomagnetism?

Paleomagnetism results from the zone of magma 'locking in' the Earth's magnetic polarity when it cools


What is the measurement of resilience?

The ability to survive disruptions to their livelihood and normal well being, despite the impact of the natural disaster.


What are the 4 features of development that relate to vulnerability?

1. Economic.
2. Social.
3. Environmental.
4. Political


What is the economic component to development?

The improvement of wealth can help the quality of life,.


What is the social component to development?

The improvement of health, education, housing and employment opportunities.


What is the environmental component to development?

The improvement of resource usage and distribution, now and for in the future.


What is the political component to development?

The improvement to human rights, political freedom and democracy.


Define the term inequality.

Unfair situation of resources. It may also be used when people, nations and non-state players have different levels of authority.


Why is earthquake forecasting very important?

It can encourage governments to enforce better building regulations in areas of high stress, or create improved evacuation procedures in areas of high risk.


How would it be possible to make accurate predictions of when and where earthquakes will happen?

Identifying a diagnostic precursor - a characteristic pattern of seismic activity or some other physical, chemical or biological change, which would indicate a high probability of an earthquake happening in a small window of space and time.
However, this method has not yet been successful.


How are geophysicists trying to improve prediction of tectonic hazards?

Calculating the underground movement of magma. Their models try o predict where the plates are running together with the most stresses, often a tell-tale sign of where an earthquake might hit.
This method still needs considerable refinement as the link between earthquakes and underground mantle flows are hard to model.


What are convection currents?

.Convection currents in the mantle move around due to the heat risen. These convection currents operate as cells.


What does the Moment Magnitude Scale (MMS) measure and on what scale?

The MMS measures the seismic moment of an earthquake such as the magnitude, the fault slip and the physical area affected.


How did the Icelandic Volcanic (2010) eruption affect car manufacturing?

-Disrupted it
-Nissan plant in Japan had to stop production of the Cube, Murano SUV and Rogue crossover models due to running out of a critical sensor produced in Iceland.
-Disrupted air freight which is only used for small quantity of high-value but vital electronic components with few alternate suppliers.


What does the Volcanic Explosivity Index (VEI) measure and on what scale?

The VEI is calculated by the volume of the earthquakes products, the height of the eruption clouds and qualitative observations.