Geography paper 1- tectonic hazards

What are the four layers of the Earth?

Crust, mantle, outer core, inner core.

What is the lithosphere?

The Earth's crust and uppermost mantle.

What is the asthenosphere?

The semi-molten layer beneath the lithosphere.

What causes tectonic plates to move?

Convection currents in the mantle.

What causes convection currents?

Heat from radioactive decay within the Earth.

What is a tectonic plate?

A large section of the Earth's lithosphere.

What is a plate boundary?

The point where two tectonic plates meet.

What is ridge push?

Gravity pushes plates away from mid-ocean ridges.

What is slab pull?

Dense oceanic crust sinks and pulls the rest of the plate.

Where do most earthquakes occur?

Along plate boundaries.

Where do most volcanoes occur?

Along plate boundaries.

What is the Pacific Ring of Fire?

An area around the Pacific Ocean with many volcanoes and earthquakes.

What causes an earthquake?

Sudden movement of tectonic plates.

What is the focus of an earthquake?

The point underground where the earthquake starts.

What is the epicentre of an earthquake?

The point on the Earth's surface directly above the focus.

What are seismic waves?

Waves of energy released during an earthquake.

What is a volcano?

An opening in the Earth's crust through which magma escapes.

What is magma?

Molten rock beneath the Earth's surface.

What is lava?

Molten rock that reaches the Earth's surface.

What is an eruption?

The release of magma, gases and ash from a volcano.

What happens at a constructive plate boundary?

Plates move apart and magma rises to create new crust.

What landforms form at constructive boundaries?

Shield volcanoes and mid-ocean ridges.

What happens at a destructive plate boundary?

Plates move together and the denser plate subducts.

What is subduction?

One tectonic plate sinking beneath another.

What landforms form at destructive boundaries?

Fold mountains, volcanoes and ocean trenches.

What happens at a conservative plate boundary?

Plates slide past each other.

Do volcanoes form at conservative boundaries?

No.

Why do earthquakes occur at conservative boundaries?

Friction causes pressure to build before sudden release.

label this

how do tectonic plates move through convection currnet

• Core Heat: The Earth's core heats the lower mantle.

• Rock Rises: Hot rock expands, becomes less dense, and slowly rises.

• Rock Cools: Near the surface, the rock cools and becomes denser.

• Rock Sinks: Gravity pulls the cold, dense rock back down toward the core.

• Continuous Loop: This circular heating and cooling cycle repeats constantly.

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what boundary is this and what happened here

constructive plate boundary, two tectonic plates pull apart from eachother