Eduqas A-Level Geology Earth structure and global tectonics overview quiz quiz

The mantle is fully molten throughout, since S waves are unable to travel through any part of it

The inner core is liquid, which is what stops S waves from reaching the far side of the planet

The outer core is liquid, because S waves cannot pass through it

The crust is uniformly thick everywhere, so S waves are blocked equally at every recording station

The core-mantle boundary

The Benioff zone

The lithosphere-asthenosphere boundary

The Mohorovicic discontinuity (Moho)

lithosphere (crust plus the rigid uppermost mantle)

crust only, since the rigid plate ends exactly at the base of the crust and the mantle plays no part

the weak, plastic asthenosphere on which the rigid plates are carried slowly across the planet

the whole mantle, from the base of the crust right down to the boundary with the liquid outer core

He provided no evidence at all for his idea, offering only the loose visual fit of the coastlines

He could not supply a convincing mechanism to move the continents

His fossil evidence was later shown to be false, as the matching species were found to be unrelated

The continents do not actually fit together, and the apparent jigsaw match is purely a coincidence

That the ocean floor is made of many different rock types arranged in neat parallel bands of stripes

That the Earth's magnetic field has never once reversed throughout the whole history of the ocean floor

That crust is created at the ridge and carried away equally on both sides

That the ridge is now volcanically extinct, the stripes being a fossil record of long-dead activity

0.5 cm per year

8 cm per year

20 cm per year

2 cm per year

Slab pull

Ridge push

Tidal forces

The Earth's rotation

flux melting from water released by a slab

decompression melting of rising mantle

friction along a transform fault

meteorite impact

The central rift valley running along the crest of a mid-ocean ridge where new crust is created

The boundary between the solid inner core and the liquid outer core deep inside the planet

The inclined plane of earthquake foci that traces a descending subducted slab

A type of transform fault along which two plates slide past one another without creating crust

The continental crust is far too thin and weak here to fold, so it simply fractures into a rift valley

Subduction is so extremely fast at this margin that the slab melts before any volcanic arc can develop

There is no friction at all between the colliding plates, so they glide past without building any relief

Both plates are buoyant continental crust, so neither subducts and the crust thickens and crumples

Magnitude is the energy at the source (one value); intensity is the effect at a place (varies with distance)

Magnitude is the shaking felt at a place and varies with distance; intensity is the single value at the source

They are simply two different names for exactly the same measurement of an earthquake's overall strength

Intensity is always measured on the Richter scale, while magnitude is judged from the damage that is observed

This single reading already pinpoints it exactly, since the time gap gives both distance and direction

Draw circles of the right radius around three stations; the epicentre is where they intersect

Measure the amplitude of the surface waves at this one station and read the position straight off it

Use the calculated magnitude of the earthquake to read off the compass direction to the epicentre

Low silica, low viscosity, gas escapes easily

High temperature, low silica, runny lava

High silica, high viscosity, gas trapped

Low gas content and low silica

The mantle plume itself slowly migrates towards the northwest while the Pacific Plate stays still

The older islands to the northwest actually erupted more recently than the active volcano did

Sea level has steadily fallen along the chain, exposing the older volcanic islands towards the northwest

The Pacific Plate moves over a roughly fixed mantle plume, carrying each volcano off the hotspot in turn