1.1.3
Theoretical Frameworks
Test your knowledge with free interactive questions on Seneca — used by over 10 million students.
The Earth's Internal Structure
The Earth can be broken down into segments such as the core, mantle, asthenosphere and lithosphere.

The core
- The core is the central part of the Earth.
- It is made up of an inner core and outer core.
- The inner core is solid, the outer core is liquid. Both are made from iron and nickel.
- The core is a source of radioactive heat.

The mantle
- The mantle is a semi-molten body of rock between the Earth’s crust and its core.

The asthenosphere
- The asthenosphere is part of the mantle.
- The asthenosphere is semi-molten.
- It is below the lithosphere, which floats on top of it.

The lithosphere
- The lithosphere is the crust and upper mantle which form the tectonic plates.
- Together they are 80-90km thick
- The crust changes in thickness under oceans and continents.
- Under oceans, the crust is 6-10km thick.
- Under continents, the crust is 30-40km thick.
The Theory of Plate Tectonics
Theoretical frameworks attempt to explain plate movements. There have been a variety of theories and discoveries over recent times. For example:

Wegener’s Continental Drift
- Wegener’s Continental Drift hypothesis (1912) said that our now separate continents had once been joined together as supercontinents e.g. Pangea.

Holmes' Hypothesis
- Holmes (1930s) said that the Earth’s internal radioactive heat was the driving force of convection currents in the mantle that could move tectonic plates.

Sea floor spreading
- In the 1960s, there was a discovery of magnetic stripes in the oceanic crust of the seabed.
- Palaeomagnetic signals from past reversals of the Earth’s magnetic field prove that new crust is created by the process of seafloor spreading at mid-ocean ridges.

Gravitational sliding
- Elevated altitudes of oceanic crust at ridges at divergent plate boundaries – create a ‘slope’ down which oceanic plates slide (gravitational sliding).

Slab pull
- At convergent boundaries, the high-density ocean floor is being dragged down by a downward gravitational force (slab pull) beneath the adjoining continental crust.
Processes at Different Plate Margins
There are four main types of process that happen at plate margins:

Processes at divergent margins
- Volcanic eruptions at divergent plate margins are basaltic and produce low viscosity lava.
- Earthquakes at divergent plate margins are low magnitude and shallow focus (less than 70 km deep).

Processes at convergent margins
- Deep-sea trenches and fold mountain ranges often form at convergent plate margins.
- Volcanic activity at convergent plate margins is often violent due to the high viscosity lava.
- Earthquakes at convergent plate margins are high magnitude, deep-focus (up to 700 km deep) and frequent.
- An example of this type of plate margin can be seen in western South America.

Processes at collision margins
- Collision plate margins are characterised by the meeting of two continental landmasses resulting in the formation of a fold mountain belt.
- E.g. The collision between the Indo-Australian and Eurasian plates has created the Himalayan mountain range.
- There is no volcanic activity at collision plate margins.
- Earthquakes at collision plate margins are rare - when they do happen, they are high magnitude and shallow-focus (less than 70 km deep).

Processes at conservative margins
- There is no volcanic activity at conservative plate margins.
- Earthquakes at conservative plate margins are high magnitude, shallow-focus (less than 70 km deep) and a common occurrence.
- An example of this type of plate margin is the San Andreas fault in California.
1Tectonic Processes & Hazards
1.1Tectonic Processes & Hazards
1.2Natural Disasters
1.3Natural Disaster Case Studies
1.4Trends & Patterns
2Option 2A: Glaciated Landscapes & Change
2.1Glaciated Landscapes Over Time
2.2Periglacial Landscapes
2.3Glacial Processes
2.4Glacial Landforms
3Option 2B: Coastal Landscapes & Change
3.1Coastal Landscapes
3.2Coastal Erosion & Deposition
3.3Coastal Risks
4Globalisation
4.1Globalisation
4.2Negatives of Globalisation
4.3Global Shift
4.5Culture
4.6Measuring Development
5Option 4A: Regenerating Places
5.1Types of Economies
5.2Function of Places
5.3Regeneration
5.4Regeneration Case Studies
6Option 4B: Diverse Places
6.1Population Structure
6.2Past & Present Connections
6.3Urban & Rural Spaces
6.4Diversity
6.5Urban & Rural Case Studies
6.6Case Study - Tower Hamlets
6.7Case Study - Sturton-le-Steeple
7The Water Cycle & Water Insecurity (A2 only)
7.1Hydrological Processes Global to Local
7.2Influences on the Water Cycle
7.3Water Insecurity
8The Carbon Cycle & Energy Security (A2 only)
8.1The Carbon Cycle
8.2Energy Consumption
8.3Alternative Energy
8.4Growing Demand for Resources
9Superpowers (A2 only)
9.1Superpowers
9.2Hard & Soft Power
9.2.1Hard & Soft Power9.2.2Emerging Powers - China Rivalry9.2.3Emerging Powers - Chinese Sources of Power9.2.4Emerging Powers - Brazil9.2.5Emerging Powers - Russia9.2.6Emerging Powers - India9.2.7Theories of Development9.2.8Power Case Studies: Chinese One Belt One Road9.2.9Power Case Studies: Pakistan Nuclear Arms9.2.10Power Case Studies: OPEC
9.3IGOs, TNCs & Alliances
10Option 8A: Health & Human Rights (A2 only)
10.1Human Development
10.2Role of Governments & IGOs
10.3Human Rights
10.4Interventions
11Option 8B: Migration & Identity (A2 only)
11.1Globalisation & Migration
11.2Consequences of Migration
11.3Nation States
11.4Responses to Global Migration
Jump to other topics
1Tectonic Processes & Hazards
1.1Tectonic Processes & Hazards
1.2Natural Disasters
1.3Natural Disaster Case Studies
1.4Trends & Patterns
2Option 2A: Glaciated Landscapes & Change
2.1Glaciated Landscapes Over Time
2.2Periglacial Landscapes
2.3Glacial Processes
2.4Glacial Landforms
3Option 2B: Coastal Landscapes & Change
3.1Coastal Landscapes
3.2Coastal Erosion & Deposition
3.3Coastal Risks
4Globalisation
4.1Globalisation
4.2Negatives of Globalisation
4.3Global Shift
4.5Culture
4.6Measuring Development
5Option 4A: Regenerating Places
5.1Types of Economies
5.2Function of Places
5.3Regeneration
5.4Regeneration Case Studies
6Option 4B: Diverse Places
6.1Population Structure
6.2Past & Present Connections
6.3Urban & Rural Spaces
6.4Diversity
6.5Urban & Rural Case Studies
6.6Case Study - Tower Hamlets
6.7Case Study - Sturton-le-Steeple
7The Water Cycle & Water Insecurity (A2 only)
7.1Hydrological Processes Global to Local
7.2Influences on the Water Cycle
7.3Water Insecurity
8The Carbon Cycle & Energy Security (A2 only)
8.1The Carbon Cycle
8.2Energy Consumption
8.3Alternative Energy
8.4Growing Demand for Resources
9Superpowers (A2 only)
9.1Superpowers
9.2Hard & Soft Power
9.2.1Hard & Soft Power9.2.2Emerging Powers - China Rivalry9.2.3Emerging Powers - Chinese Sources of Power9.2.4Emerging Powers - Brazil9.2.5Emerging Powers - Russia9.2.6Emerging Powers - India9.2.7Theories of Development9.2.8Power Case Studies: Chinese One Belt One Road9.2.9Power Case Studies: Pakistan Nuclear Arms9.2.10Power Case Studies: OPEC
9.3IGOs, TNCs & Alliances
10Option 8A: Health & Human Rights (A2 only)
10.1Human Development
10.2Role of Governments & IGOs
10.3Human Rights
10.4Interventions
11Option 8B: Migration & Identity (A2 only)
11.1Globalisation & Migration
11.2Consequences of Migration
11.3Nation States
11.4Responses to Global Migration
Practice questions on Theoretical Frameworks
Can you answer these? Test yourself with free interactive practice on Seneca — used by over 10 million students.
- 1Earth's Structure Put in order
- 2What makes up the lithosphere?Multiple choice
- 3What is true of the Earth's structure?True / false
- 4
- 5
Unlock your full potential with Seneca Premium
Unlimited access to 10,000+ open-ended exam questions
Mini-mock exams based on your study history
Unlock 800+ premium courses & e-books