Plate Tectonic Theory Overview

The theory that Earth's outer layer is made of large, moving slabs called tectonic plates. These plates interact at their boundaries, causing earthquakes, volcanoes, and mountain formation.

Convection currents in the Earth's mantle, driven by heat from the core, cause the movement of tectonic plates. Hotter, less dense magma rises, while cooler, denser magma sinks, creating a circular flow.

A force that pushes tectonic plates apart at divergent plate boundaries. Magma rises, cools, and forms new crust, pushing the plates further away from each other.

A force that pulls tectonic plates downward at convergent plate boundaries. The denser plate subducts under the less dense plate, pulling the rest of the plate along.

The process where tectonic plates move apart at divergent plate boundaries, allowing magma to rise and create new oceanic crust in the gap.

Plate boundaries where two tectonic plates move apart (diverge), creating new crust and often volcanic activity.

A type of constructive plate margin where two oceanic plates move apart, allowing magma to rise and form underwater volcanoes and new oceanic crust.

When tectonic plates move past each other horizontally, causing friction that can release energy as earthquakes.

A mixture of volcanic gases, like sulfur dioxide, that combine with water vapor in the atmosphere to form acidic compounds like sulfuric acid. This acidic rain can damage buildings, infrastructure, and harm aquatic ecosystems.

Materials ejected during a volcanic eruption, ranging in size from massive rocks to microscopic particles. These materials can devastate surrounding areas.

The process of volcanic gases, particularly carbon dioxide, increasing the concentration of heat-trapping gases in the atmosphere, contributing to global warming.

The impact of volcanic eruptions on the surrounding environment, from damaging ecosystems through ash fallout and acid rain, to impacting global climate through reduced sunlight.

The negative consequences of volcanic eruptions on the economy, including damage to infrastructure, disruptions to transportation, and losses in tourism revenue.

The devastating social impacts of volcanic eruptions, such as loss of life, destruction of homes, displacement of communities, and trauma.

The challenges faced by governments in the aftermath of volcanic eruptions, including rebuilding infrastructure, providing emergency aid, addressing food shortages, and managing political tensions.

Short-term responses to volcanic eruptions, focusing on immediate actions to protect people and mitigate damage, such as evacuations, emergency supplies, and attempts to control lava flows.

Long-term responses to volcanic eruptions, involving strategies like improving prediction and warning systems, adapting land use, and utilizing resources available in the volcanic region.

The eruption of Mount Pinatubo in the Philippines, a major event that caused significant social, economic, and environmental impacts.

Areas of volcanic activity not related to plate boundaries. They form when hot magma plumes from the mantle rise and burn through weaker parts of the crust, creating volcanoes and islands. The plume remains in the same spot, while the plates move, sometimes forming a chain of islands.

When two plates collide, they form a destructive margin. The denser oceanic plate subducts beneath the continental plate, creating a deep sea trench and fold mountains. As the plate subducts, the magma rises and forms volcanoes along the plate margins.

The process where new land forms on the ocean floor as lava fills the gaps between diverging plates.

The area where two tectonic plates slide past each other horizontally. No volcanic activity occurs, but they can form powerful earthquakes due to the pressure buildup.

These are formed when the lithosphere stretches and fractures, causing the land between the faults to collapse into deep, wide valleys. Such valleys are separated by upright blocks of land called horsts.

Continental-continental plate collisions create fold mountains as sediments deposited beneath them become uplifted and compressed.

Radioactive decay within Earth's core generates very hot temperatures. If the decay is concentrated, hot spots form around the core. These heat the lower mantle, creating localized thermal currents where magma plumes rise vertically.

When two plates collide, the denser oceanic plate subducts beneath the continental plate, leading to the formation of a deep sea trench and fold mountains. Magma rising from the Benioff zone forms volcanoes along the plate margins.

The rising magma from the Benioff zone forms crescent-shaped submarine volcanoes along the plate margins, which may grow to form island arcs once the lava cools and creates new land.

These are the areas where two plates move apart or diverge. New basaltic rocks and ocean crust are formed by basaltic magma rising from the asthenosphere. Other features include mid-ocean ridges, shallow focus earthquakes, and rift valleys.

Plates diverging and moving away from each other, resulting in the formation of new ocean crust and mid-ocean ridges.

The lifted areas of rocks are known as horsts, whereas the valley itself is known as a graben.

Oceanic divergence forms a chain of submarine mountain ridges that extend for thousands of kilometers across the ocean floor. These ridges are cut by regular breaks called transform faults, which occur at right angles to the plate boundary.

These are the areas where two plates collide or converge. They can lead to the formation of fold mountains, deep sea trenches, and volcanoes, depending on the types of plates involved.