Tectonic Hazards & Processes

Question 1

What is a Conservative plate margin?

Answer 1

Plates sliding past each other, friction and pressure is built up overtime and the plates then end up slipping. Causes earthquakes.

Question 2

What is a Convergent plate margin?

Answer 2

Occurs when the denser oceanic plate subducts below continental plate at subduction zone. Volcanoes are formed and earthquakes occur.

Question 3

What is a Divergent plate margin?

Answer 3

Plates move apart causing a gap between plates with magma rising up generating new crust. E.g. Mid-Atlantic ridge.

Question 4

What is a collision plate margin?

Answer 4

2 continental plates collide and neither can sink so fold mountains are created.

Question 5

Coping capacity

Answer 5

Ability of people, organisations and systems to use available resources to manage adverse conditions, risks, and disasters.

Question 6

Earthquake

Answer 6

Sudden violent shaking of the ground caused by a sudden release of energy as a result of a build up of stress between 2 tectonic plates.

Question 7

Epicentre

Answer 7

Point on earth’s surface directly above the hypocentre (focus).

Question 8

Focal depth

Answer 8

Depth below the earth’s centre of the hypocentre.

Question 9

Volcano hotspots

Answer 9

Large plume of hot mantle material rising from deep within the earth. A line of shield volcanoes is formed as the plate moves over the hotspot.

Question 10

Layers of the earth

Answer 10

-inner core (5200 degrees, most dense)
-outer core
-mantle
-Crust = (oceanic- younger+denser)
(Continental- older+thicker)

Question 11

What is liquefaction?

Answer 11

Earthquake shakes wet soil causing the loosely packed, water logged sediments near ground surface to lose strength. Cause buildings to sink.

Question 12

Primary impacts of volcanoes.

Answer 12

Pyroclastic flow- fast moving, dense flow of solidified lava pieces, volcanic ash and hot gases. Burns anything in its path.

Gas emissions- (e.g. sulfur dioxide, carbon dioxide, hydrogen sulfide) lead to acid rain

Lava flow- Magma from mantle erupts forming streams of molten rock that destroy anything in their path.

Lahar (volcanic mudflow)- Water mixed with volcanic debris

Question 13

Moment magnitude scale

Answer 13

Measures earthquake by the distance moved and force required to move it.

Question 14

Plate tectonics

Answer 14

Theory explaining why earth’s crust acts in a certain way and produces landforms we can see on the earth’s surface.

Question 15

Volcanic explosivity index (VEI)

Answer 15

Measures magnitude of volcanic eruption on a scale of 0-8.