physical geography t1 Flashcards

1
Q

what is a divergent plate boundary

what kind of earthquakes occur

A

a divergent plate boundary is where plates move apart which means that magma rises and cools forming new crust and forming a mid ocean ridge.

only mostly small shallow earthquakes

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2
Q

what is a convergent plate bondary

what dose it do to volcanoes and earthquakes in the area

A

plate boundary that push together deforms the collision area. material melts in the mantel

more earthquakes and the formation of active volcanoes

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3
Q

what is a conservative plate boundary?

what results as a result of movment

A

it is where the plates move along side each other

can resulting the formation of mountains swell as well as quite strong shallow focus earthquakes

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4
Q

give an example of a conservative boundaries

what generally causes earthquakes at these boundaries

A

San Andres fault

realses of friction

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5
Q

where are divergent boundaries

what is made as they move apart

A

they are generally oceanic crust under the ocean

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6
Q

what is the most dangerous plate boundary generally and why

A

convergent
as the plates approach each other one of them subject typically the denser and thinner crust which is the oceanic crust
- this causes friction which when realised causes very powerful earthquakes

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7
Q

what is comon above a subduction zone

A
  • montaian belt
  • magmatic activity
  • active siesimity
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8
Q

what is a destructive boundary

A

convergent plate boundary

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9
Q

what forms when 2 continental plates meet

A

fold montains

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10
Q

what is created at a divergent plate bondaries

A

-rift volcanoes, generally less explosive and more effusive

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11
Q

what are hotspot volcanoes and how are they formed

A

they are found in the middle of the plate and are formed by magma plumes threw the plate

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12
Q

where is the majority of volcanic activity

A

plate boundaries

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13
Q

what is the most common type of natural disaster

what is the least common type of natural disaster

A

hydrlogical

Geophysical

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14
Q

what makes a natural event count as a disaster

what about a mega disisater

A

10 pepole dead

?

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15
Q

case study toku 2011
- cuase
-size
-deaths
-economic impact
-response

A

tohku earthquake 2011
-undersea earthquake at plate junctions measured 9.0 on the magnitude scale
-15,653 people killed 90% by drowning, 100,000 choldren sperated from there famiies 300,000 people in total displaced
-220 billion dollars in damage, 47,700 buildings destroyed, 230,000 vehicles destroyed, goverment debt increased due to an injection of billions of yen to restart the economy
-100,000 japanese self defence force members came to help aswell as the red cross and US military personal sent to aid the rescue

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16
Q

what cuases tunamis

A
  • earthquake(realsea of tention) can cause a subduction of plate or mega thrust of the plate = displacement of water and a wave motion created
  • displacment of water through large movement of sediment of metorite in water
17
Q

what is a disaster

A

+100 pepepole die in an event

18
Q

what is a mega diaster

A

over 2000 deaths

19
Q

what factors effect vulnerability of a country/ settlement

A
  • location
    -education
    -investment in adaption measures
    -planning for disasters and hazards
20
Q
A

Haiti

21
Q

name 3 ways in which a volcanic activity can be mitigated

A

-tilt meters can tell when a volcano is bulging and close to erupting
-boar holes tell how different the temperature is as magma rises
- building concrete shelters from volcanic ash and lava bombs

22
Q

name 3 hazards of volcanic activity

A
  • ash fall can be heavy on roofs which cuases them to collapse, distrups machinarie and flight paths and kills crops
    -plyromcaltic flow- flow of tephra and poisonous gases moves down the side of the volcano at almost 700km/h
    -lava flows down the side of the mountains and cools
    -lahars mixture of water and volcanic material traveling down river valleys at 60km/h
    -gas eruptions- water vapouoir and sulfur dioxide can be poisonous high high concentrations
    cuase acid rain which cuases damage to buildings and plants and blocks sun energy
23
Q

case study Indian ocean tsunami
- causes

A

case study Indian ocean tsunami
-It was caused by a rupture along the fault between the Burma plate mega thrust earthquake magnitude 8.8
-