Tectonic plate boundaries are the main locations where geophysical hazards occur, making them a central focus in IB Geography, particularly within Option D: Geophysical Hazards. These boundaries mark the edges of tectonic plates, where movement causes stress, friction, and energy release. The type of boundary determines the nature and severity of the hazards produced.

At convergent plate boundaries, plates move towards each other. When an oceanic plate collides with a continental plate, the denser oceanic plate is forced beneath the continental plate in a process known as subduction. As the plate descends, it melts, forming magma that rises to the surface and causes volcanic eruptions. Stress builds up along the plate interface, and when it is released suddenly, powerful earthquakes occur. These earthquakes can also displace large volumes of water, generating tsunamis.

When two continental plates collide, neither plate subducts easily. Instead, the crust is compressed and uplifted, forming mountain ranges. Although volcanic activity is limited, shallow but intense earthquakes are common due to the build-up and release of stress along fault lines. These earthquakes can be highly destructive because they occur close to the surface.

At divergent plate boundaries, plates move apart. As the crust separates, magma rises from the mantle to fill the gap, creating new crust. This process produces volcanic activity that is typically less explosive than at convergent boundaries. Earthquakes also occur as the plates pull apart, but these are usually smaller in magnitude. Divergent boundaries are commonly found along mid-ocean ridges, meaning many hazards occur underwater and pose limited direct risk to human populations.

Transform plate boundaries occur where plates slide past each other horizontally. Friction along the boundary prevents smooth movement, causing stress to build up over time. When the stress is released suddenly, earthquakes occur. These earthquakes can be extremely damaging, particularly when they occur near densely populated areas. Unlike convergent and divergent boundaries, transform boundaries do not usually produce volcanoes.

In IB Geography, it is important to recognise that tectonic hazards are not random. Their distribution closely follows plate boundaries, allowing scientists to identify high-risk regions. However, predicting the exact timing and magnitude of hazards remains extremely difficult.

Human factors strongly influence the impact of tectonic hazards. Population density, building design, preparedness, and governance determine whether a hazard becomes a disaster. Poorly planned urban areas near plate boundaries are particularly vulnerable.

Overall, tectonic plate boundaries create hazards through plate movement, stress accumulation, and energy release. The type of boundary determines whether earthquakes, volcanoes, or tsunamis occur, shaping global patterns of risk.

RevisionDojo helps IB Geography students understand tectonic hazards clearly, linking plate boundary processes to real-world impacts and exam-ready explanations.