Theme 3 Tectonic Landscapes and Hazards

Question 1

How is an Ocean trench formed?

Answer 1

When oceanic and continental plates converge, the oceanic plate will be forced underneath the continental as it is denser.

Question 2

How do volcanic Hotspots form?

Answer 2

Intensive radioactivity in the Earths interior creates a huge column of upwelling magma known as plume. The plume pushes upwards melting the earths crust and lies under a fixed position under the tectonic plate. When the plate moves over the hotspot the magma creates a succession of new volcanoes.

Question 3

What are 4 main hazards that come from a volcano?

Answer 3

Pyroclastic flow
Ash clouds
Lahars
Lava flows

Question 4

What are some monitoring techniques used to detect a tectonic hazard?

Answer 4

Seismometer- detects vibrations in earths crust
laser beams- used to detect plate movement
Levels of gas that gets emitted
Tiltmeter used to see if a volcano has increased magma
buoys in ocean may detect a tsunami
warning systems will play

Question 5

Give some examples of emergency planning:

Answer 5

-Exclusion zones set up near volcanos
-Evacuation routes planned
-Lava flows can be diverted
-Trained emergency services
-Education
-Emergency kits (canned food, supplies, first aid)
-Roads and bridges build to withstand the power
-Earthquake proof buildings