Earth Science

What is heat?

A form of energy and measure of the total energy of all particles.

What is temperature?

A measure of the average kinetic energy of particles in a substance.

What is heat transfer?

Flows from areas of high temperature to areas of low temp. The larger the distance, the faster heat flows.

Define Conduction.

When heat is passed by the vibration of particles. (Direct contact)

Define convention.

Transfer of heat in a liquid or gas due to less dense. (Mass motion of molecules)

Define Radiation.

Energy transferred by electromagnetic waves, which can travel through a vacuum.

Define Subduction.

Refers to when oceanic crust and continental crust collide, oceanic crust is denser so it goes under the continental crust.

Define Seafloor spreading.

The process of new crust forming at the ocean ridges ad spreading outwards.

What is a diverging boundary?

When plates move in opposite directions away from each other.

What do diverging boundaries create?

When plates separate it creates a rift. Magma rises up into the rift and solidifies as it cools.

What is a convergent boundary?

When two plates collide into each other

What do converging boundaries create?

These collisions form features like mountains.  Rock is destroyed as the plates collide so these are also called destructive boundaries.

What is a transform boundary?

Locations where two plates slide past one another.

What do transforming boundaries create?

Shallow earthquakes, large lateral displacement of rock, and a broad zone of crustal deformation.

What is the plate tectonic theory?

An explanation for how the continents move- earths crust is like a jigsaw puzzle made of giant sections called tectonic plates that move by convection currents. Plates float on top of the mantle.

Define an ocean crust.

On the ocean floor; generally below sea level (more dense)

Define Continental crust`

forms the continents; generally above sea level (less dense)

What is a plate boundary?

The area where 2 tectonic plates meet.

What plate boundary regions have a lot of activity?

1. Diverging North American and Eurasian boundaries create the Mid-Atlantic ridge.

2. Converging North American, pacific, Indian-Australia and Nazca boundaries create the Ring of Fire.

3. Transforming North American and Pacific plates create the San Andreas fault.

Where are some divergent boundaries located?

African and South American plates, North American and Eurasian plates and Australian and Antarctic plates.

What plate boundaries more commonly have volcanos and earthquakes?

Convergent plate boundaries due to subduction- Australian and Pacific plates and North American and Pacific plates.

Are there any plate boundaries where earthquakes/volcanos don’t occur?

1. The antarctic plate has the least amount of earthquakes

2. Transform boundaries have shallow earthquakes so theres little to no volcanic activity.

Where does the most plate tectonic activity occur?

The Ring of Fire is a string of volcanoes and sites of seismic activity, or earthquakes, around the edges of the Pacific Ocean. (Eurasia and North American Plates)

What is an island arc?

Long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries

Explain the formation of island arcs/chains

1. Forms from volcanic activity in subduction zones.

2. Subduction occurs when oceanic lithosphere travels underneath continental or oceanic crust.

3. It pushes up other landforms.

4. Creates hotpots, allowing magma to travel through the athenosphere

5. Some comes to the surface, forming volcanoes.

What is an earthquake?

Rapid movement of the ground, back and forth and up and down in a wave motion.

What’s the science behind earthquakes?

1. Fast release of energy as the tectonic plates move.

2. When the force between plates is big enough, the plates send waves on energy.

3. Rocks and water then start shaking

What can earthquakes cause?

Land slides, soil liquefaction and tsunamis

What is a volcano?

Place where extremely hot material from inside the Earth erupts at the Earth's surface.

Explain the science behind volcanos?

Magma accumulates in weak spots, and sometimes the magma is pushed up under great pressure.

How many types of volcanoes are there?

There are four:

1. Stratovolcano- Cone-shaped, violent eruptions

2. Caldera- Large, land subsides during large eruptions

3. Shield-Weak eruptions, broad with gentle slopes.

4. Mid-ocean ridge- transform faults, continuous range of underwater volcanoes

What is a tsunami?

Larger version of regular waves- trough and crest and unrelated to tidal activity

Explain the science behind tsunamis?

1. Movement of energy through water from under water

2. Water rises but gravity pulls it back down and causes it to ripple outwards.

3. This creates a tsunami

4. Only detectable on the coast because there is less water to move through, energy becomes compressed and the waves grow

Define Epicenter.

The point of Earth’s surface directly above the focus of an earthquake.

Define Primary waves (P-Waves).

A longitudinal seismic wave that travels fast through earth.

Define secondary waves (s-waves).

Transverse seismic wave that travels through Earth.

What are surface waves?

When particles move in a circular motion

What is the difference between a seismometer and a seismograph?

1. The seismograph is the paper record of seismic waves

2. A seismometer is an instrument that responds to ground noises and shaking

Which one of the 3 seismic waves causes the most destruction? And why?

Surface waves because surface waves produce more ground movement and travel more slowly, so they take longer to pass.

Compare between the focus and epicentre of an earthquake.

The focus is the place inside Earth's crust where an earthquake originates. The point on the Earth's surface directly above the focus is the epicenter.

What were the two main observations that led to the theory of continental drift?

The fit of the continents and the distribution of fossils.

List 3 pieces of evidence that support seafloor spreading.

molten material, sediment thickness and drilling samples.