Restless Earth Flashcards

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1
Q

Describe the features of a Destructive plate boundary

A

Plates move together
Continental and Oceanic crust
Volcano formed, Ocean Trench, Earthquake and Fold Mountain

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2
Q

Describe the features of a Constructive plate boundary

A

Plates move apart
Oceanic and Oceanic crust
New land is formed, earthquake

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3
Q

Describe the features of a Conservative plate boundary

A

Plates slide past each other
Continental and Continental crust
Earthquake

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4
Q

Give 2 differences between oceanic and continental crust

A
Oceanic
Newer less than 200 million years
Denser and can sink
Continental
Older more than 1500 million years
Less dense and cannot sink
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5
Q

Define Anticline

A

Upfold of folded rock

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6
Q

Define Syncline

A

Downward fold of folded rock

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7
Q

Overfold

A

Rock fold that is folded over to one side

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8
Q

What plates do fold mountains occur at?

A

Destructive plate boundaries

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9
Q

State two differences between acidic and basic lava

A
Acidic 
High silica content 
Vicious and travels short distances before cooling 
Composite volcanoes 
Basic 
Low silica content 
Pours easily and travels far before cooling 
Shield volcano
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10
Q

What is the difference between lava and magma

A

Magma is underground and lava is on the surface of the earth

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11
Q

Give 3 factors of a composite volcano

A
  1. Acidic Lava
  2. Cone is tall with steep slope
  3. Irregular with long dormant periods
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12
Q

Give 3 factors of a shield volcano

A
  1. Basic Lava
  2. Cone has gentle slopes and wide base
  3. Regular frequent eruptions
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13
Q

What is the pacific ring of fire?

A

A destructive plate boundary around the pacific ocean where half of the volcanoes and earthquakes are

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14
Q

What is the subduction zone?

A

Where the oceanic plate subducts under the continental plate. This is where an oceanic trench is.

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15
Q

Give four uses of volcanoes

A
  1. Farming on fertile soils
  2. Tourist attractions (hot springs and walking)
  3. Geothermal energy
  4. Mining for valuable minerals eg Pumice
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16
Q

Give 3 ways volcanoes can be predicted and monitored

A
  1. Seismometers, when magma begins to move there will be hundreds of earthquakes
  2. Monitoring gases escaping from the volcano like Sulphur dioxide
  3. Scientists listening to gurgles as the magma moves
17
Q

Give 3 responses to a volcano erupting

A
  1. Pouring seawater on the magma to solidify it
  2. Evacuation
  3. Airlifting huge concrete blocks to divert the magma flow
18
Q

Describe supervolcanoes

A

Mega colossal
Emit 1000 km3 of lava
Only occur at hotspots, weak areas of crust

19
Q

Describe the characteristics of Super Volcanoes

A

They are in large depressions in the ground called Calderas
They have no cone
Rim of the ground is higher than the actual volcano

20
Q

How is the distribution of Supervolcanoes different to Volcanoes

A

There are less than 10 Super Volcanoes in the world
3 are in North America
They do not occur at plate boundaries only hotspots

21
Q

How do earthquakes occur and at what plate boundary

A

Occur at all plate boundaries
Caused when tension is released from inside to crust
Plates do not run smoothly and sometimes get stuck
This builds up pressure that is released in an earthquake

22
Q

Define Epicentre

A

The point on the earth surface directly above the focus

23
Q

Define Focus

A

The point in the earth’s crust where the earthquake originates

24
Q

Define Seismic waves

A

Shock waves generated by the earthquake at the focus and pass through the earths crust

25
Q

What are earthquakes measured on?

A

Seismograph measures magnitude (size)

26
Q

Give four differences of the Richter and Mercalli scale

A
Mercalli
Uses roman numerals I-XII
Measures the impact of earthquake
Measured after eq
Measured through observation
Richter 
Uses numbers 1-10
Measures the shaking
Measured during the eq 
Goes up logarithmically eg 7 is 10x bigger than 6
Measured on a seismograph
27
Q

What is a major earthquake?

A

7.0 on the Richter scale

28
Q

Give three reasons why a same magnitude earthquake would have a varied impact

A
  1. It was at night (no warning)
  2. People may live near the epicentre
  3. It may cause a tsunami
29
Q

What are the 3 P’s of earthquakes?

A

Predict
Protect
Prepare

30
Q

Give two example of Predict

A
  1. Animals act strangely and crawl out of their homes and dogs howl
  2. Earthquakes are more likely after long periods without plate movement
31
Q

Give two examples of Protect

A
  1. Buildings must comply with new earthquake standards

2. Cross bracing on buildings and shock absorbers

32
Q

Give two examples of Prepare

A
  1. Organise emergency supplies of food water and power in advance
  2. Train emergency services like Fire and Ambulance
33
Q

What is the differences between Prepare and Protect

A

Prepare is for people, Protect is for buildings

34
Q

Give three reasons to support the theory of plate tectonics

A
  1. The continents fit together like jigsaws
  2. There is similar soils in different parts that would be together
  3. There is the same fossil ages in parts that would be joined
35
Q

Explain convection currents

A

Circular currents of magma under the earth crusts that explains why plates move towards and away from each other