HAZARDS & tectonic plates

Question 1

define hazard

Answer 1

harmful elements of the physical environment caused by extraneous forces.

Question 2

define natural phenomenon

Answer 2

physical event that doesn’t affect humans

eg) cyclone yvette

Question 3

define natural disaster

Answer 3

physical event that causes large amounts of property damage and over 10 deaths.

Question 4

define natural hazard

Answer 4

natural phenomenon that occurs in a populated area creating a hazard.
(Eyjafajallajokull 2010)

Question 5

classifications of hazards

Answer 5

geomorphological, atmospheric, biological, tectonic

BUT the categories can become blurred.

Question 6

Hazard Perception… eg?

Answer 6

way someone interprets/ understands a hazard

fatalism, adaption, domination, fear

Question 7

fatalism

Answer 7

nothing can be done = acceptance (god?)

Question 8

adaption

Answer 8

action taken to reduce vulnerability

Question 9

domination

Answer 9

hazards are predictable and can be understood with science

Question 10

fear

Answer 10

ppl flee to unaffected regions

Question 11

3 ways to respond to hazards

Answer 11

prevention, prediction and AID

Question 12

What is the park model?

Answer 12

show changing quality of life through different phases of disaster ( 1-5) as humans respond.

Question 13

stages of the park model (NHRRR)

Answer 13

1) NORMALITY = preparation/ modification
2) HAZARD = declining quality of life & ppl protect
3) RELIEF(hrs and days) = search, care & rescue
4) REHABILITATION(days-wks) = improvements to modify loss - water, food, shelter
5) RECONSTRUCTION(wks-yrs)= reduce vulnerability and restore normality / improve.

Question 14

Hazard Management cycle (four stages) RRMP

Answer 14

RESPONSE = minimise hazard
RECOVERY = return to normality
MITIGATION = minimise effects of disaster
PREPAREDNESS = planning effective response.

Question 15

Problem with Hazard Management Cycle

Answer 15

steps do not occur chronologically = overlap and severity and development affect duration.

Question 16

Earths age

Answer 16

4.6 billion yrs old

Question 17

describe the inner core

Answer 17

solid and made from nickel and iron

6000*C

Question 18

describe the outer core

Answer 18

liquid and made from nickel and iron

4-5000

Question 19

describe the Mantle

Answer 19

the thickest section

made of silicate of iron, magnesium, sulphides and oxides.

Question 20

difference between the asthenosphere and the lithosphere

Answer 20

Asthenosphere = soft, plastic rock that makes convection currents 
Lithosphere = solid upper part of mantle and crust = tectonic movement

Question 21

describe the continental crust

Answer 21

thicker, older, less dense than oceanic

Question 22

describe oceanic crust

Answer 22

thiner, younger and denser than continental

Question 23

evidence of continental drift (7)

Answer 23

jigsaw fit, fossil correlation, rock and mountain correlation, paleoclimate data, see floor spreading, paleomagnestism

Question 24

example of paleoclimate data

Answer 24

glacial striation

Question 25

rock composition of oceanic crust

Answer 25

basalt, gabbro and silma

Question 26

rock composition of continental crust

Answer 26

granite and sial

Question 27

what is paleoclimate data?

Answer 27

study of how characteristics of land match with the climate eg) glacial striation sign of moving glaciers = must have one been in cold environment

Question 28

what are some signs that land must have been in a different climate?

Answer 28

glacial striations and coal deposits.

Question 29

what processes finally proved Wegener’s theory of continental drift

Answer 29

sea floor spreading and paleomagnetism

Question 30

how often does the earths magnetic field swap?

Answer 30

every 400,000 yrs … or so.

Question 31

What is ridge push? (gravitational sliding)

Answer 31

an alternative hypothesis for the mechanism of plate movement.
- magma rises to surface at plate ridge
- surrounding rock becomes very hot and expands
- expansion elevates the sea floor = slopes either side
- rock formed cools and condenses = gravity pulls it inwards = moved apart down slope away from ridge.
(sea floor spreading pushes plates away from ridge)

Question 32

what is slab pull?

Answer 32

a more dominant theory for plate movement

• subducted oceanic plate is denser
• the sinking plate pulls the rest of the plate down further with its weight.

Question 33

geographical features found at constructive plate boundaries

Answer 33

mid ocean ridge - chain of submarine volcanoes
shield volcanoes
rift valleys - fractures form between two plates - new and sinks due to movement = steep sided valley.

Question 34

geographical features at destructive plate boundaries

Answer 34

ocean trenches - subduction zone between plates
fold mountains - andes
island arcs - chain of volcanic islands 
volcanoes
earthquakes

Question 35

geographical features at collision plate boundaries

Answer 35

fold mountains - continental plates collide - neither subducted = crust buckles and crumples

Question 36

geographical features at conservative plate boundaries

Answer 36

plates do not pass smoothly = friction locks plates and courses earthquakes when pressure is released = changing structure of land.

Question 37

magma plumes

Answer 37

vertical column of magma that rises up from the earths causing a volcano to form away from a plate margin.

Question 38

geographical features of magma plumes

Answer 38

supervolcano

island arc - plates move over hotspot and weaknesses in the rock allow magma to escape onto the surface.

Question 39

benioff zone

Answer 39

and inclined zone in which lots of deep earthquakes can occur as subducted rock is melted and destroyed.
found beneath destructive boundaries where oceanic plate is being subducted.