General stuff Flashcards
(39 cards)
Hazard -
Perceived natural threat that has the potential to threaten life and property.
Disaster -
A series of disruption of the functioning of a community or a society involving widespread human, material of environmental and economic loss.
The main earthquake zones are found where and what %?
70% of earthquakes are found in the ring of fire in the Pacific ocean.
The violence of of a volcanic eruption is determined by?
The amount of dissolved gas in the magma and how easily that gas can escape.
What percentage of the 500 active volcanoes erupt each year?
10%
Divergent plate boundaries context -
Two plate boundaries move away from each other (diverge away).
What is formed when two continental plates pull away from each other?
Rift valleys such as one in Africa.
When two oceanic plates move away pull away what is formed?
Sub-marine volcanoes (shield volcanoes)
Do earthquakes occur when divergent plates move away?
Yes because friction occurs
Convergent plate context -
When two plates move towards each other
When two oceanic plates move together which one subducts?
The faster moving one
When an oceanic and continental plate move together which one subducts?
Denser one which is oceanic
If two continental plates move together what is formed?
Fold mountains
Plate boundaries that move towards each other generate some of the most damaging earthquakes for example Japan 2011 earthquake and tsunami that resulted from a convergent plate boundary -
A strain builds up over time in the subduction zone. Causes friction.
Conservative context -
When two plates slide past each other, results in shallow earthquakes being formed.
Hotspot formation are formed in?
The middle of a plate instead of a plate boundary. Due to the inner core being 6000 degrees
Hotspot volcanoes activity -
Due to it being active, its explosions cause it to grow into an island arc, the are generally less explosive due to they occurring in the subduction zone.
Secondary hazards of earthquakes are?
Liquefaction and landslides
Liquefaction (E - secondary impacts) -
Causes buildings to tilt collapse in the most series events, of up to 60 degrees can be recorded.
Landslides (E - secondary impacts) -
Landsides occur when slopes weaken and fail, landslides can travel several miles from their origin growing in size and collecting trees, boulders cars and other materials, 70% of all earthquake deaths are caused by landslides. Kashmir earthquakes 1/3 of deaths were due to landslides.
Primary impacts of volcanoes - (PF)
Formed by frothing of molten magma in the vent of the volcano, the bubbles explode explosively to eject hot gasses, these ejected clouds can be up to 1000 degrees and cannot be outrun.
Secondary impacts of Volcanoes -(L)
Lahars as mudflows usually composed of fine sand and silt. Hazard depends on the steepness of the slope the volume of material too, can be associated with heavy rainfall.
Primary impacts of volcanoes - (T)
Tephra it will eject some material as it erupts such as rock fragments it can vary in size from large pieces, this can affects air travel and can cause building roofs to collapse.
Secondary impacts of Volcanoes - (J)
Jokulhapus (glacial outburst of floods) Hazard to people and widespread landform leading to erosion and deposition of material (use glacial facts).
