Stop the Earth! What would happen if the movement of tectonic plates came to a halt?

The movement of tectonic plates on Earth causes some of the deadliest disasters on the planet, but the cessation of their movement could be an even worse alternative.

Tectonic plates rest upon a liquid layer of rock known as the asthenosphere. According to scientists, this is part of Earth's upper mantle, and although it consists of solid rock, it flows like a liquid due to the immense heat and pressure coming from below.

When molten rock is pushed up from the Earth's core, it moves in opposite directions across the asthenosphere until it cools and sinks back down to the core. This process is called convection, and it is responsible for the shifting, separating, or colliding of vast land masses.

Plate tectonics explains the disappearance of the ancient supercontinent Pangaea. However, tectonic plate movement is still ongoing. The plates are constantly shifting, causing the Atlantic Ocean to expand while the Pacific Ocean contracts. In about 250 million years, there may once again be only one continent on Earth.

If we were to imagine for a moment that all this movement came to a halt, it would likely signal the end of all life on the planet.

For tectonic plates to stop moving, the Earth's mantle must become too cold for convection to occur. If this happens, it indicates that the Earth's outer core has probably solidified.

The typically liquid outer core transfers heat between the inner core and the mantle. But if this heat transfer process is disrupted, Earth could either become an ice ball or a fireball.

On one hand, if heat cannot reach the mantle or crust, the entire planet could freeze. On the other hand, plate movement helps regulate our planet's internal temperature since the convection process cools the hot molten rock from the Earth's core. Without the ability to cool, the inner core could ignite our planet.

Regardless of whether it becomes a hot or cold planet, Earth's topography will become much less interesting.

Converging plates create impressive mountain ranges and terrifying volcanoes. But without plate tectonics, Earth would simply stop creating new ones. The mountains we have now will erode over millions of years, turning into low hills. Eventually, our planet will flatten out, and more land will be submerged underwater.

On the flip side, the number of natural disasters would decrease. Without subduction zones where two plates converge, earthquakes would become rare and less powerful. Volcanoes, for the most part, would cease to function since tectonic activity usually triggers their eruptions.

However, if volcanoes are inactive, then so is Earth's magnetic field. Our magnetic field is powered by convection currents in the iron outer core. But if this process is disrupted, we lose our magnetic field. Without a magnetic field, Earth would no longer be shielded from deadly solar winds. The sun would strip away our atmosphere, sucking away the air we breathe and evaporating the oceans. At that point, life on Earth would become impossible.

While the movement of tectonic plates may create problems on Earth, the absence of this movement would render our planet simply uninhabitable.