Booklet Glossary

Vibrations which travel as waves without transferring matter outputted by an earthquake.

The gradual movement of the continents across the Earth’s surface through geological time.

A single supercontinent that existed 230 million years ago.

The super ocean that surrounded the super continent of Pangaea.

A theory explaining the structure of the earth’s crust and many associated phenomena as resulting from the interaction of rigid lithospheric plates which move slowly over the underlying mantle.

The mostly solid rock that makes up most of the Earth’s interior.

A heat driven cycle which causes the flow of magma in the mantle.

The relatively thick part of the crust which forms landmasses.

The relatively thin part of the crust which underlies ocean basins.

Ocean mountains on plate boundaries.

When one plate forces underneath another on a convergent plate boundary.

The northern hemisphere half of the supercontinent Pangaea when it split.

The southern hemisphere half of the supercontinent Pangaea when it split.

An upwards bend in folding rock.

A downwards bend in folding rock.

A fracture or discontinuity in a volume of rock across which there has been significant displacement.

A steep-sided valley formed by the downward displacement of a block of the earth’s surface between nearly parallel faults or fault systems.

A raised elongated block of the earth’s crust lying between two faults.

Vertical, or nearly vertical, fractures where the blocks have mostly moved horizontally

The point where an earthquake originates but on the surface.

The point inside the Earth’s crust where the earthquake originates

Instruments which record the motion of the ground during an earthquake.

A base-10 logarithmic scale, meaning that each order of magnitude is 10 times more intensive than the last one, used to measure the magnitude of earthquakes.

A weak vibration in the ground which can’t be felt by humans but can be detected by sensitive seismometers.