October 16, 2021
To understand the formation of continents, let's begin with a few geographical terms:
Continent: The landmasses that make up nearly 30% of Earth’s surface. The seven continents are Asia, Australia, Africa, Europe, North America, South America, and Antarctica.
Continental Drift: The movement of Earth's crust over the planet’s liquid core.
Meteorology: The study of Earth’s atmosphere. People involved in weather analysis and forecasting are called meteorologists.
Lithosphere: Earth has three main layers: the Crust (uppermost), the Mantle, and the Core (which is liquid in part). The Crust and the Upper Mantle together form the Lithosphere.
Pangaea: A Definition
Now that we’ve covered the terms, here’s the definition:
Pangaea was a supercontinent that existed around 250 million years ago, when all the continental lithospheres on Earth were joined into a single landmass.About 100 million years later, Pangaea began to break apart—eventually forming the seven (not-so-small!) continents we recognize today.
The Man Behind the Theory
A German meteorologist named Alfred Wegener proposed the Pangaea Theory in 1912. He hypothesized that continents move over time—a groundbreaking idea that introduced the concepts of continental drift and supercontinents.
Wegener offered several key pieces of evidence:
Fossil Evidence: Fossils of Lystrosaurus were found in India, Africa, and Antarctica. Since it’s unlikely these species swam across oceans, they must have once lived on the same landmass.
Matching Fossil Records: Fossils of mosasaurs were found on both the east coast of South America and the west coast of Africa, suggesting the two continents were once connected.
Geological Similarities:
Identical radioactive minerals have been found in Germany and Canada.
Mountain structures in Western Europe and the northeastern United States are strikingly similar, indicating the regions were once part of a single landmass.
Together, these clues support Wegener’s theory.
Climate Change After Pangaea
The breakup of Pangaea drastically altered the Earth's climate. As the continents separated, they changed the flow of ocean currents and atmospheric winds. This shift had global consequences. The scientific explanation for these changes lies in Continental Drift—Wegener’s theory that continents move over time, affecting climate, geology, and ecosystems. For example, Wegener studied plant fossils from the frigid Arctic region of Svalbard, Norway. He found fossils of tropical plants not adapted to cold climates. Since such plants couldn’t migrate, Wegener concluded that Svalbard must have had a much warmer climate in the past.
As Pangaea split apart, new ocean basins and seaways formed, disrupting global temperature regulation. When North and South America connected, they blocked equatorial currents from flowing between the Atlantic and Pacific Oceans. This diverted more warm currents toward Europe and strengthened the Gulf Stream. Warmer waters at high latitudes caused more evaporation, increasing atmospheric moisture and precipitation. One consequence was the development of Greenland’s ice cap, which contributed to global cooling.
More evidence of global cooling comes from the separation of Australia and Antarctica and the formation of the Southern (Antarctic) Ocean. The new ocean allowed for a circumpolar current—a powerful flow of cold water around Antarctica. This current cut off warm, tropical air and water from reaching the continent, turning Antarctica into the icy landmass it is today.
From Continental Drift to Plate Tectonics
Although many of Wegener’s conclusions were later confirmed, science has since evolved. His theory of Continental Drift was eventually replaced by the more comprehensive theory of plate tectonics, which better explains how Earth's crust moves and reshapes over time.
Final Thought
Modern Homo sapiens are a relatively recent species—only about 100,000 to 200,000 years old. Pangaea, by contrast, existed over 335 million years ago. So, there were definitely no humans—or even primates—on Pangaea!
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