On the surface of a hot liquid, convection currents can be seen. The solid crust of the Earth functions as a heat insulator for the planet’s hot interior. The heated liquid rises to the surface, causing an up current in the middle of the liquid. The molten magma moves in convection currents due to the intense heat and pressure within the Earth. These currents cause the tectonic plates that make up the Earth’s crust to shift. In turn, the convection current causes the lithospheric plate to move. The crust (lithospheric plates) moves due to the pressure from the rising material from the hot spot. You might ask why do lithospheric plates move? Continue reading to know about it.
1. What are Lithospheric Plates?
A tectonic plate, also called a lithospheric plate, is a massive solid rock slab made up of continental and oceanic lithosphere. The Pacific and Antarctic Plates are among the largest, with diameters ranging from a few hundred to thousands of kilometers. Plate tectonics is a widely held scientific idea that the Earth’s lithosphere comprises a series of huge tectonic plates that have been moving slowly since around 3.4 billion years ago. (See What makes up the Lithosphere?)
2. What is a Convection Current?
Before you read about convection current causes the lithospheric plate to move, you must have an idea of what convection currents are. Convection is the natural movement of a single or multiphase fluid generated by interacting material property and earth’s heterogeneity with body forces (density and gravity). Temperature gradients induce changes in the density of the fluid, which causes convection currents.
The activity that results from the constant replacement of the heated fluid in the vicinity of the heat source by the neighboring cooler fluid is known as a natural convection current. The better heat and mass transmission induced by this natural convection current is referred to as natural convection heat and mass transfer. (See What is Revolution and Rotation?)
3. How is Conduction and Convection Interrelated?
Heat is conveyed across an intermediary medium in convection, whereas heat is transferred through a heated solid mass in conduction. Between a solid surface and a moving liquid or gas, convection is a mechanism of energy transmission. Also, check out what are the Northern Lights?
4. Why does Convection occur in Mantle?
Mantle convection occurs when relatively hot rocks are less dense and rise in a gravitational field, whereas relatively cold rocks are denser and sink. Hot rocks advect heat upward, whereas cold rocks advect heat downward, resulting in upward heat flux. To know more about why do convection current causes the lithospheric plate to move, read on. Also, check out what are the 6 Layers of the Earth?
5. Why do Lithospheric Plates move constantly?
The Earth is in a state of flux at all times. The lithosphere, or Earth’s crust, is made up of 15 to 20 tectonic plates that move back and forth. The plates, which resemble pieces of a shattered shell, lay on the warm, molten rock of Earth’s mantle and fit closely against one another. The heat released by radioactive processes in the planet’s core causes the plates to shift, bringing them closer and further apart. Also, check out what is the difference between Oceanic Crust and Continental Crust?
6. What are the 3 causes of Plate Movement?
According to scientists, three mechanisms are hypothesized to be responsible for plate movement.
- Mantle convection is one of them. Convection occurs when heat and density differences cause materials to move in currents. Warm particles circulate during convection, and hot particles rise to the top while cold ones fall to the bottom.
- Ridge push is another idea for plate movement. At mid-ocean ridges, older rock is forced downward and away from the ridge as magma rises from the mantle to generate new oceanic crust.
- Subduction zones and a phenomenon known as slab pull are the subjects of the third theory of plate movement. Slab pull occurs when thick tectonic plates descend beneath less dense plates. This causes the rest of the plate behind it to pull. Slab pull and ridge pressure create a conveyor belt effect between tectonic plates. (See Top 10 Major Mountain Ranges of the World)
7. How is Convection Current related to Movement of Plates?
You know that convection current causes the lithospheric plate to move. Let’s dig deeper. According to some geologists, convection currents in the mantle are the primary cause of plate tectonic motion. This is because the mantle is made up of magma, which is a semi-molten rock. Furthermore, in the same way, convection currents can occur at a much more boiling temperature and can exist in the mantle. (See What Layer of the Earth does Magma come from?)
Convection currents cause Earth’s hard tectonic plates to move in the planet’s fluid molten mantle. Seafloor spreading is a phenomenon in which tectonic plates shift away from each other in areas where convection currents flow up towards the crust’s top.
8. How Convection Current causes the Plates to move?
Movements deep within the Earth cause the crust to move. Convection currents are formed by radioactive decay in the core as heat rises and falls inside the mantle. Convection currents propel the plates forward. Plates divide where convection currents diverge near the Earth’s crust.
The convection current causes the lithospheric plate to move slowly but steadily. Convection currents from the lower mantle and core transport heat to the lithosphere. The heat from the mantle’s convection currents causes the crust to become more flexible and less thick when tectonic plates drift away. (See Where is the Center of the Earth Located?)
9. What is the Effect of the Movement of the Lithosphere?
After knowing that the convection current causes the lithospheric plate to move, let’s understand what the effects of this movement are. At the seams where tectonic plates clash, crustal rocks may grind violently against one another, causing earthquakes and volcano eruptions. The tectonic plates cause frequent earthquakes in California beneath the state, moving at a rather fast rate. Mountains can be formed, or volcanoes can erupt as a result of the movement of these plates. Strong earthquakes can occur when tectonic plates collide, causing the Earth’s surface to quiver. (See How are Volcanoes Distributed on the Map?)