Question

How did Greenland become separated from North America?

Short answer

Greenland became separated from North America due to the process of plate tectonics, specifically rifting. Both landmasses were initially part of the supercontinent Pangaea, which began to break apart around 200 million years ago. The rifting process caused the lithosphere to crack and split apart, allowing magma to rise to the surface, leading to volcanic activity and further splitting. Over time, the Atlantic Ocean was formed between Greenland and North America as the North American Plate and the Eurasian Plate moved in opposite directions. The separation continues even today, with Greenland drifting away from North America at a rate of about 2.5 cm per year.

Step-by-step solution

Understanding Plate Tectonics

Plate tectonics is a geologic theory that explains the movement of the Earth's lithosphere. The theory suggests that Earth's outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core. This movement of plates leads to earthquakes, volcanic activity, the creation of mountain ranges, and the differentiation of continents and oceans.

The Origin of Greenland and North America's Connection

Greenland and North America were once a part of the same landmass. They were part of the supercontinent known as Pangaea, which began to break apart approximately 200 million years ago.

Separation Process

The separation process began with what geologists call rifting. Rifting is a process where the lithosphere and asthenosphere, layers of the Earth's crust, start to split apart. Magma or molten rock from the Earth's mantle rises to the surface, causing the lithosphere to crack and split apart. This process is accompanied by volcanic activity, causing further splitting or cracking of the lithosphere.

Formation of the Atlantic Ocean

As rifting continued, a new ocean was formed between Greenland and North America, which we now know as the Atlantic Ocean. This ocean continued to expand as the North American Plate and the Eurasian Plate (the plate that includes Greenland) moved in opposite directions.

Final Separation

Over millions of years, the ocean between Greenland and North America widened, completing the separation process. However, the plates continue to move, meaning that Greenland is still gradually moving away from North America.

Continued Movement

Even today, the plates continue to drift slowly, at a speed of about 2.5 cm per year. So, Greenland continues to move away from North America slowly, this plate tectonics process is still ongoing. This is why Greenland and North America are not only separated but continue to become more distant from each other.