How Tectonic Plates Alter Sea Level

Do you know how tectonic plates alter sea level? Since the Earth was formed millions of years ago, the land beneath us has been constantly moving. Science believes that when Earth was first formed, the continents formed one big land mass. Scientists have named this solo landmass Pangea. Over time, plates beneath the surface of the Earth moved and pulled the landmass apart to form the continents that we have come to know today. These plates that lie beneath the Earth’s surface, called tectonic plates, still constantly are on the move today. So, how do these tectonic plates alter sea levels?

When tectonic plates move beneath the visible surface of the Earth, the movements can have an effect on the sea level. For instance:

• When tectonic plates collide with one another and push the surface of the Earth upwards, this can lower the sea level.
• Collisions can also cause the coastlines of some areas to rise, which also changes the sea level.
• As plates move away from one another and create rifts in the oceans or on land this can cause the sea level to rise.

The movements of the tectonic plates, therefore, can alter sea level in a variety of ways depending on what particular types of movements the plates are undergoing at a given time.

About Tectonic Plates

Part of understanding how tectonic plates alter sea level involves also understanding how tectonic plates work. Tectonic plates compromise the whole of the Earth’s lithosphere. The lithosphere is the rigid upper most part of the Earth’s surface. Below the lithosphere is the asthenosphere.

The lithosphere rides along the asthenosphere, which is low in viscosity, so the plates slide smoothly along this surface. The plates move and create three different types of boundaries. The three different types of boundaries that can be created due to the movement of the Earth’s tectonic plates are:

• Convergent or Collision Boundaries – This boundary is created as two plates slide toward one another. There are two types of convergent boundaries. They can create either subduction zone as one plate slides below another or a continental collision in which the plates move and push upward creating mountain ranges like the Andes or islands like the Japanese Island arc. These are the boundaries along which volcanic activity is known to occur.
• Divergent Boundaries – These types of boundaries are created as the plates below the Earth’s surface slide away or apart from one another. The sliding away creates a ridge such as the Mid-Atlantic Ridge or Africa’s Great Rift Valley.
• Transform Boundaries – These boundaries occur when two plates slide along each other at the edge. This sliding can occur in two directions either towards or away from the observer. The plates sliding against one another create earthquakes. The San Andreas Fault line in California is an example of a transform boundary.

So, now you know how tectonic plates work and how tectonic plates can alter sea level.