Question

Why do plates move?

Answer 1

Hint: The Earth’s surface is broken up into large plates while plates and the Earth’s crust, which is the thin outermost layer of the Earth are both different.Basically plates refer to the sections into which the lithosphere is cracked.

Complete answer: The movement of molten magma present inside the earth causes the movement of plates. In general, Plates move because of the tectonic recurrence in the lithospheric region. The lithosphere is broken into a number of plates that is termed as the Lithospheric plates. These plates move around in a very slow motion, only a few millimetres each year. The surface of the Earth is divided into 7 major and 8 minor plates.The movement of these plates results in changes on the Earth's surface.
In general, the mechanism due to which the tectonic plates move is still a subject of much debate among Earth scientists. The Earth is dynamic, due to its internal heat, that comes from deep within the mantle from the breakdown of radioactive isotopes. It was long thought that the same caused convection currents in the mantle that were considered responsible for the movement of tectonic plates across the surface of the Earth.
Anyhow, this theory is now majorly out of favour, with modern imaging techniques that are unable to identify mantle convection cells which are sufficiently large to drive plate movement. Some plate models also represent that two thirds of the surface of the Earth moves faster in comparison to the underlying mantle hence there appears to be little or no evidence showing that convection currents in the mantle move plates (apart maybe from some very small plates in unusual circumstances).

Note: As per the scientists, there exists about eight major tectonic plates and numerous minor plates which act as the Earth’s outer skin. The plates existing under the oceans are called oceanic plates and the ones under continents are called the continental plates. The largest plates are the Antarctic, Eurasian, and North American plates. Plates are on average around 125km thick, that reaches the maximum thickness below the mountain ranges. Oceanic plates (50-100km) are thinner as compared to the continental plates (up to 200km) and even thinner at the ocean ridges where the temperatures are relatively higher. Some plates are generally large enough in order to consist of both continental and oceanic crustal portions (e.g. the African or South American plates) whilst the Pacific Plate is almost completely oceanic.