## Who derived the plate theory?

Alfred Wegener

Alfred Wegener in Greenland. Plate tectonics is the theory that Earth’s land masses are in constant motion. The realization that Earth’s land masses move was first proposed by Alfred Wegener, which he called continental drift.

### What is classical plate theory?

In continuum mechanics, plate theories are mathematical descriptions of the mechanics of flat plates that draws on the theory of beams. Plates are defined as plane structural elements with a small thickness compared to the planar dimensions. The typical thickness to width ratio of a plate structure is less than 0.1.

#### Which plate theory assumes that the normals to the plate do not remain orthogonal to the mid plane after deformation thus allowing for transverse shear deformation?

The Kirchhoff plate theory or Kirchhoff–Love plate theory that was derived to calculate the deformations and stresses within a plate is the foundation generally adopted for the formulation of a thin plate.

**How did Wegener discovered plate tectonics?**

Plate tectonic theory had its beginnings in 1915 when Alfred Wegener proposed his theory of “continental drift.” Wegener proposed that the continents plowed through crust of ocean basins, which would explain why the outlines of many coastlines (like South America and Africa) look like they fit together like a puzzle.

**What are thin plates?**

Thin plates are used in civil, aeronautical, and mechanical structural elements. In all these fields the plate can be in a state of in-plane force applied parallel to its plane. Compressive in-plane loads can lead to buckling, implying the loss of stability of the plate.

## Which principle is used to derive the governing equations of displacement based plate theories?

Clarification: Governing equations of displacement-based plate theories are derived using the principle of virtual displacements, the principle of virtual displacements directly yields the weak forms of the governing equations.

### Which is correct option for shear deformation theory?

Shear Deformation Theory is an extension of the Timoshenko beam theory.

#### Why is Harry Hess the founder of plate tectonics?

In 1962, he proposed a groundbreaking hypothesis that proved vitally important in the development of plate tectonic theory. It addressed several geologic puzzles: If the oceans have existed for at least 4 billion years, why has so little sediment accumulated on the ocean floor?