tectonics L1 dynamic landscapes

Question 1

How are Earthquakes distributed?

Answer 1

on or around a plate boundary

• mid-Atlantic ridge

Question 2

How is volcanic activity distributed?

Answer 2

along constructive & destructive boundaries

• Nazca-South America Boundary

Question 3

How are Tsunamis distributed?

Answer 3

happen along mostly destructive boundaries around the pacific

anomaly — many around the mediterranean which is an uncertain boundary

Question 4

What is the Lithosphere?

Answer 4

The crust & the upper most solid mantle

Question 5

What is the Asthenosphere?

Answer 5

Semi-molten rock (99% solid) in the upper mantle
Viscous/ductile which allows lithosphere to glide on top

Question 6

What is the Mesosphere?

Answer 6

lower mantle — high pressure from layers above — more rigid

Question 7

What is Mohorovičić discontinuity (Moho)?

Answer 7

The boundary between the crust and the mantle — 10-12km under ocean bed

Question 8

Crust — Temperature

Answer 8

Surface temp to about 400°C

Question 9

Crust — Density & Composition

Answer 9

Continental - Granite (Less Dense) (up to 100km), Oceanic - Basalt (7km thick)

Question 10

Crust — Physical state?

Answer 10

solid

Question 11

Mantle — Temperature

Answer 11

870°C

Question 12

Mantle — Density & Composition

Answer 12

silicate
less to medium density
700km to 2890km deep

Question 13

Mantle — Physical State

Answer 13

Phases of liquid and solid in layers
(semi molten)

Question 14

Outer Core — Temperature

Answer 14

4400 to 6100°C

Question 15

Outer Core — Density & Composition

Answer 15

dense
12% sulphur
88% iron

2890 to 5150km deep

Question 16

Outer Core — Physical State

Answer 16

liquid (and generates magnetic field)

Question 17

Inner Core — Temperature

Answer 17

7000°C
(Radioactive decay & pressure)

Question 18

Inner Core — Density & Composition

Answer 18

20% nickel
80% iron

5150km to centre deep

very dense

Question 19

Inner Core — Physical State

Answer 19

Solid (+ radiates heat)

Question 20

Destructive Plate Boundaries

Answer 20

oceanic plate subducts under continental plate into BENIOFF ZONE

shallow, intermediate & deep focus EQs

Question 21

Conservative Plate Boundaries

Answer 21

only earthquakes

only shallow (30km) focus EQs

Question 22

Constructive Plate Boundaries

Answer 22

two oceanic plates
magma rises and cools forming land

effusive volcanic activity

Question 23

Collision Boundary

Answer 23

Two continental
destructive

fold mountains

Question 24

What are Intra-Plate Earthquakes?

Answer 24

Earthquakes that occur in the middle of a plate due to pre-existing weaknesses that become reactivated forming seismic waves

— Newcastle in 1989

Question 25

What are Hot Spot Volcanoes?

Answer 25

Located in the middle of plates has unusually high temps due to the rising magma from the core — The Ring of Fire.

Question 26

What is Oceanic Crust (SiMa)

Answer 26

Silica and Magnesium

Question 27

What is Continental Crust (SiAl)

Answer 27

Silica & Aluminium