October 16, 2021
This article is from my hand written notes from the late 1990s, they clearly demonstrate that I had a lot to learn!
To understand the process of formation of continents, let us understand a few geographical terms:
- Continent: The landmasses that constitute nearly 30% of Earth; the seven continents or landmasses are – Asia, Australia, Africa, Europe, North America, South America, and Antarctica.
- Continental Drift: It is the process of movement of Earth’s crust on the liquid core.
- Meteorology: The study of Earth’s atmosphere is called meteorology. The folks involved in Weather Processing, Forecasting, etc. are called Meteorologists.
- Lithosphere: The Earth constitutes of three layers broadly: Crust (uppermost layer of Earth), Mantle and Core (Liquid Core). Together, the Crust and Upper Mantle make the Lithosphere.
- Now that you know the geographical words, it’s easy to define:
- A supercontinent that was formed 250 million years ago when all the continental lithospheres of the Earth united to form one supercontinent known as Pangea.
- What followed after 100 million years was the breakup of the supercontinent, resulting in the formation of seven small (not really) continents we know now!
The Man Behind
- A German Meteorologist called Alfred Wegener proposed the Pangaea Theory in 1912. It was a hypothesis that continents move around the world over time!
- For the first time in History, the theories of continental drift, supercontinent, and Pangaea came into being.
- Alfred proposed that the continents that look like this now
- Fossils of Lystrosaurus were present in India, Africa and Antarctica! Therefore, it is impossible that dinosaurs or other species would swim and travel to all these countries. They have to stay in one place!
2. Similar patterns were present in the fossils found from various places: Fossils of mosasaurs were present in both east coast of South America and Western Coast of Africa
3. Mountains, Minerals, and Rocks!
Do you know that there are some identical radioactive minerals exist in Germany and Canada! In addition, similar half-life or time decay patterns in a few minerals also reinforce the idea of a single continent.
Apart from that, the mountain structures of Western Europe and the North Eastern States are also similar. Surely, there was a common landmass shared between the two continents! Hence, proving the Theory.
Climate change after Pangaea
The reconfiguration of continents and oceans after the breakup of Pangea changed the world’s climate. There is scientific evidence that this change was drastic. When the continents separated and reformed themselves, it changed the flow of the oceanic currents and winds. The scientific reasoning behind all of the changes is Continental Drift. The theory of Continental Drift, created by Alfred Wegener, explained how the continents shifted Earth’s surface and how that affected many aspects such as climate, rock formations found on different continents and plant and animal fossils. Wegener studied plant fossils from the frigid Arctic of Svalbard, Norway. He determined that such plants were not adapted to a glacial climate. The fossils he found were from tropical plants that were adapted to thrive in warmer and tropical climates. Because he would not assume that the plant fossils were capable of traveling to a different place, he suspected that Svalbard had had a warmer, less frigid climate in the past.
When Pangaea separated, the reorganization of the continents changed the function of the oceans and seaways. The restructuring of the continents, changed and altered the distribution of warmth and coolness of the oceans. When North America and South America connected, it stopped equatorial currents from passing from the Atlantic Ocean to the Pacific Ocean Researchers have found evidence by using computer hydrological models to show that this strengthened the Gulf Stream by diverting more warm currents towards Europe. Warm waters at high latitudes led to an increased evaporation and eventually atmospheric moisture. Increased evaporation and atmospheric moisture resulted in increased precipitation. Evidence of increased precipitation is the development of snow and ice that covers Greenland, which led to an accumulation of the icecap. Greenland’s growing ice cap led to further global cooling Scientists also found evidence of global cooling through the separation of Australia and Antarctica and the formation of the Antarctic Ocean. Ocean currents in the newly formed Antarctic or Southern Ocean created a circumpolar current. The creation of the new ocean that caused a circumpolar current eventually led to atmospheric currents that rotated from west to east. Atmospheric and oceanic currents stopped the transfer of warm, tropical air and water to the higher latitudes. As a result of the warm air and currents moving northward, Antarctica cooled down so much that it became frigid.
Although many of Alfred Wegener’s theories and conclusions were valid, scientists are constantly coming up with new innovative ideas or reasoning behind why certain things happen. Wegener’s theory of Continental Drift was later replaced by the theory of tectonic plates.
Modern Homo sapiens is a relatively new species, between 100,000–200,000 years. Pangea existed 335,000,000 years ago, so there were definitely no humans (or even primates) on Pangea.