Geophysical systems are a core focus in IB Geography, particularly within Option D: Geophysical Hazards. These systems explain how natural processes within the Earth create hazards such as earthquakes, volcanoes, and tsunamis. Understanding geophysical systems allows students to explain why hazards occur, where they are located, and how they behave over time.

At the centre of geophysical systems is the Earth’s internal structure. The Earth is made up of the crust, mantle, and core. Heat generated in the core drives convection currents in the mantle. These convection currents cause the movement of tectonic plates at the Earth’s surface. This movement is the main source of geophysical hazards.

A key characteristic of geophysical systems is that they are driven by energy transfers. Heat energy from the Earth’s interior is transferred toward the surface. This energy movement creates stress at plate boundaries. When stress is released suddenly, it results in earthquakes. When molten material rises through weaknesses in the crust, volcanic eruptions occur.

Tectonic plate boundaries are another defining feature of geophysical systems. Most geophysical hazards occur along plate margins where plates interact. At convergent boundaries, plates collide, creating powerful earthquakes and explosive volcanoes. At divergent boundaries, plates move apart, allowing magma to rise and form volcanoes. Transform boundaries produce earthquakes as plates slide past each other. In IB Geography, understanding boundary types is essential for explaining hazard distribution.

Geophysical systems also involve feedback loops. For example, volcanic eruptions release ash and gases into the atmosphere, which can affect climate temporarily. Earthquakes may trigger landslides or tsunamis, increasing the overall impact of a single event. These secondary hazards show that geophysical systems are interconnected rather than isolated.

Another important characteristic is that geophysical systems operate on different timescales. Plate movement occurs very slowly, often just a few centimetres per year. However, the release of energy during an earthquake or eruption happens suddenly and violently. This contrast explains why hazards can appear unpredictable even though they are part of long-term geological processes.

In IB Geography, it is important to recognise that geophysical systems interact with human systems. Population growth in hazard-prone areas increases exposure and vulnerability. Urban development, poor construction, and lack of planning can turn natural events into disasters. The hazard itself is natural, but the level of impact is shaped by human factors.

Overall, geophysical systems are characterised by internal energy, tectonic plate movement, boundary interactions, feedback loops, and varied timescales. These systems explain the global distribution and behaviour of geophysical hazards.

RevisionDojo helps IB Geography students understand geophysical systems clearly by linking Earth processes, hazard patterns, and exam-style explanations into confident, structured responses.