how do scientists explain the fact that some landforms that are far apart and separated by oceans appear to be related?

Continental drift

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Scientists explain the fact that some landforms that are far apart and separated by oceans appear to be related through a concept known as plate tectonics. Plate tectonics is the scientific theory that describes the Earth's outer shell, or lithosphere, as broken into several large plates that float on the semi-fluid asthenosphere below.

To understand why these landforms appear to be related, we need to know a bit about how plate tectonics works. The Earth's tectonic plates constantly move and interact with each other. There are three main types of plate boundaries: divergent boundaries, where plates move apart; convergent boundaries, where plates collide; and transform boundaries, where plates slide past each other horizontally.

Over millions of years, these plate movements can cause landforms to form and change. For example, when two plates move apart at a divergent boundary, molten rock called magma rises from the Earth's mantle and creates new oceanic crust. As the magma cools and solidifies, it forms mid-ocean ridges, which are long mountain chains that separate the boundary between two plates. This process is called seafloor spreading.

These oceanic plates can carry landforms with them as they move. For instance, if a large piece of land is attached to an oceanic plate, it can be transported across the ocean and ultimately collide with another continent or plate. This collision is known as a continental collision or orogeny. When two continents collide, the immense forces involved can result in the formation of mountain ranges, such as the Himalayas.

So, when scientists observe similarities between landforms that are far apart and separated by oceans, they can infer that these landforms were once connected or formed under similar geological processes. By studying the movement of tectonic plates and reconstructing past plate configurations, scientists can explain and understand the relationships between distant landforms. They use evidence from geology, paleomagnetism, fossil records, and other geological techniques to piece together the history of Earth's landforms.