Tectonic plates are large, rigid pieces of Earth's lithosphere that are responsible for the movement and configuration of our planet's surface. The Earth's crust contains immense rock formations known as tectonic plates, which are segmented into multiple sections and undergo gradual movement due primarily to the planet's internal heat. There are different types of tectonic plate edges.
Structure and movement of tectonic plates
Cortex
The composition of the Earth can be divided into different layers. The Earth's internal structure comprises three concentric layers, each with its own unique composition and dynamics. These layers include the core, mantle, and crust. The crust, which forms the tectonic plates, It is fragmented and varies in thickness and surface characteristics. You can also expand your knowledge about the formation of these structures in our article How are mountains formed.
The movement of tectonic plates through generations. The study of seismic waves, specifically seismic refraction and reflection, has provided valuable information about the composition of the Earth's interior, revealing the existence of three distinct zones or layers, one of which is the Earth's crust.
The composition and thickness of this type of rock varies depending on whether it is found in oceanic or continental regions. It is formed through the differentiation of the mantle, resulting from partial fusion. The oceanic crust varies in thickness, between 7 and 25 km, and is predominantly formed by basaltic rocks. On the other hand, the continental crust is thicker, measuring between 30 and 70 km, and is composed mainly of andesitic rocks.
Manto
It makes up approximately 85% of the Earth's volume and extends from the Moho to the boundary between the mantle and the core, with a depth of approximately 2.891 km. These processes are related to the types of plates and their interaction in the terrestrial dynamism.
The transfer of heat from the planet's inner core to the crust is facilitated by its function as a heat conductor. This phenomenon, called convection currents, drives the movement of tectonic plates. To better understand how these processes affect the Earth's surface, you can find more information in our article on The lights seen in Mexico after an earthquake.
Core
Confirmation of a magnetic field generated by heavy elements such as iron, nickel, vanadium and cobalt through interaction with internal heat is supported by its average radius of 3481 km. The main origin of this heat can be attributed to two main sources.
There are two main sources of heat within the Earth: the initial heat generated by planetesimal impacts and the release of gravitational energy during planet formation, and the heat produced by the radioactive decay of elements such as uranium, thorium, and potassium. . Additionally, the movement of plates in the asthenosphere also contributes to the overall distribution of heat within the Earth.
Interactions between plates
The interactions between the lithospheric plates, which make up the outermost surface of the Earth, result in a series of geological phenomena such as volcanic activity, deformations of the earth's crust, seismic events and sedimentary processes. To delve deeper into how these interactions generate movements in the cortex, you can also consult our analysis on How earthquakes alter the elastic properties of the Earth's crust. This is directly related to their movements and effects.
Plate movement is primarily caused by internal heat generated within the lithosphere. Several key factors contribute to this phenomenon. The lithosphere experiences pressure from the ascending asthenosphere, known as ridge thrust, while the subsidence of the old oceanic lithosphere exerts a force called slab pull. The importance of these forces lies in their impact on the rate of plate migration and the corresponding proportion of the plate margin connected to the subduction zone.
The slab suction process involves the retreat of the subducted lithosphere, while the opposing force is exerted by viscous drag in the asthenosphere. Over time, extensive studies have contributed to the development and understanding of the theory of plate tectonics.
Plate tectonic theory
The theory of plate tectonics combines the concept of continental drift with the process of seafloor spreading, creating a comprehensive understanding of Earth's geological phenomena. The movement of the Earth's plates is facilitated by the expansion of the oceanic or continental crust that covers the lithosphere, which allows them to move across the planet's surfaceThis expansion is related to phenomena such as the birth of new crusts at mid-ocean ridges, which you can explore in articles related to the process of plate tectonics.
Earth's tectonic plates are large sections of the planet's crust that move and interact with each other. Seafloor spreading is the result of convection in the mantle, leading to the formation of oceanic crust at mid-ocean ridges. As time passes, this crust gradually moves away from the ridge. Over time, the crust can submerge and undergo destruction as it converges with another tectonic plate.
Most of the highly destructive earthquakes that occur on Earth, with a higher Richter scale, can be attributed to the movement of tectonic plates. To learn more about how these movements affect the surface, we invite you to visit our article on .
Tectonic plate boundaries
Tectonic Plate Theory categorizes different types of plate boundaries within its framework. The observable consequences of tectonic forces are most pronounced at the narrow contact zones, known as plate boundaries, where movement occurs. To understand in-depth how these boundaries occur, you can read how they influence plate formation. Underwater volcanoes and their ecological impact. Also, if you want to delve deeper into its types and differences, we recommend you review our article on .
The different types of plate boundaries include divergent plate boundaries. Convergent boundaries, also known as destructive boundaries, are those where plates collide and interact with each other. These boundaries can be classified into three types: oceanic-continental, oceanic-oceanic, and continental-continental. In oceanic-continental convergence, the denser oceanic plate subducts beneath the less dense continental plate, forming a trench and triggering volcanic activity. This process leads to the creation of mountain ranges, such as the Andes. Oceanic-oceanic convergence occurs when two oceanic plates collide, resulting in the formation of volcanic islands, such as Japan and the Philippines.
Finally, continental-continental convergence occurs when two continental plates collide, causing intense deformation and the formation of mountain ranges, such as the Himalayas. The collision between the Indian and Eurasian plates gave rise to the majestic Himalayan mountain range. These convergent boundaries are dynamic and constantly shape the Earth's surface for millions of years.
Destructive boundaries, also known as subduction boundaries, occur when the crust is destroyed as one plate subducts beneath another. This process involves recycling the crust as the plates move together and one sinks beneath the other. To better understand how these subductions occur, we recommend reviewing our article on Earthquakes and their relationship with subduction zones.
When two oceanic plates come together in a process known as oceanic-oceanic convergence, one plate typically subducts beneath the other, resulting in the formation of a trench. An example of this can be seen in the Mariana Trench, which runs parallel to the Mariana Islands.
On conservative limits, also known as transformation limits, occur when the Earth's crust slides horizontally between plates, neither created nor destroyed. The Mediterranean-Alpine region, located between the Eurasian and African plates, is an example of these boundaries. Several smaller plate fragments, known as microplates, have been identified in this area.
