Plate tectonics and earthquakes: what are the two historical figures and the process of mantle convection and plate movement.I understand that the whole continent moves but what is plate tectonics and the historical figures that contributed to the plate technonic theory and how would the plates move by boiling a pot of water and relating it to mantle convention and plate movement. I just don't understand how this process can happen.
Read these sites carefully.
http://www.ucmp.berkeley.edu/geology/tectonics.html
http://pubs.usgs.gov/gip/dynamic/dynamic.html
Thank you Sue.
Plate tectonics refers to the scientific theory that explains the movement and interactions of Earth's lithospheric plates. The theory states that Earth's lithosphere, which consists of the crust and uppermost portion of the mantle, is divided into several large plates that float on the semi-fluid layer beneath known as the asthenosphere.
The primary mechanisms behind plate tectonics are mantle convection and the associated forces generated by it. To understand the concept of mantle convection, imagine a pot of boiling water. As the water is heated, currents develop within the pot. The hot water rises to the surface, cools down, and then sinks back down. This cycle of rising and sinking creates a circular motion known as convection.
In a similar way, the Earth's mantle, which lies beneath the crust, experiences convection currents due to the heat generated by the core. The heat causes the mantle material to become less dense, making it rise towards the surface. As it reaches the top, it cools down, becomes denser, and sinks back down. This pattern creates a continuous cycle of mantle convection.
The movements of the mantle convection currents are responsible for the movement of the tectonic plates. The plates essentially float on the semi-fluid asthenosphere, and the convection currents push, pull, and drag the plates in different directions. Depending on the specific boundary between two plates, they can either move apart (divergent boundary), slide past each other (transform boundary), or collide (convergent boundary).
Now, let's discuss the historical figures who made significant contributions to the theory of plate tectonics:
1. Alfred Wegener: In the early 20th century, Alfred Wegener proposed the theory of continental drift. He noticed that the Earth's continents seemed to fit together like a jigsaw puzzle and proposed that they were once part of a single supercontinent called Pangaea. Wegener suggested that the continents had slowly moved apart over time and were still in motion. Although his ideas were initially met with skepticism, they eventually paved the way for the acceptance of plate tectonics.
2. Harry Hess: In the 1960s, Harry Hess proposed the theory of seafloor spreading. He observed that the rocks on the ocean floor were much younger compared to those found on the continents. He suggested that new crust was forming at oceanic ridges, where magma from the mantle was welling up and creating new seafloor, pushing the existing seafloor aside. This led to the idea that the seafloor was spreading and moving away from the ridges.
Both Wegener's theory of continental drift and Hess's theory of seafloor spreading were key to the development of our understanding of plate tectonics. Over time, the theories coalesced into the comprehensive model of plate tectonics that we know today.
In summary, plate tectonics refers to the movement and interaction of Earth's lithospheric plates. This movement is primarily driven by mantle convection currents, which are generated by heat from the core. The historical figures Alfred Wegener and Harry Hess made significant contributions to the development of the plate tectonics theory through their ideas of continental drift and seafloor spreading, respectively.