The Atlantic Ocean is growing. It has been expanding gradually for millions of years, at a rate of approximately 1.5 inches per year, as a result of the movement of tectonic plates. This expansion continues to this day. Conversely, the Pacific Ocean is shrinking.
Understanding the Growth of the Atlantic Ocean
The Atlantic's growth is a direct consequence of plate tectonics. The supercontinent Pangea broke apart approximately 180 million years ago, initiating the formation and subsequent expansion of the Atlantic. [Source: Insider, 04-Mar-2024]. This ongoing expansion is driven by the movement of tectonic plates under the Americas, Europe, and Africa [Source: Business Insider, Aug 24, 2023]. Hot, molten rock rises from the Earth's mantle, pushing these plates apart and widening the ocean basin. [Source: Live Science, Jan 28, 2021]. This process is a slow, continuous geological phenomenon. [Source: Cosmos Magazine, Feb 18, 2024]
While the Atlantic is currently expanding, projections suggest that this trend may reverse in the distant future, with the Atlantic eventually beginning to shrink in approximately 20 million years. [Source: Cosmos Magazine, Feb 18, 2024]. This future shrinkage would require the formation of new subduction zones—a complex geological process. [Source: The Week, Mar 4, 2024].
Ocean Size Changes and Sea Level Rise
It's important to differentiate between the changes in ocean size and changes in global sea level. The Atlantic's growth refers to the physical expansion of the ocean basin. Global sea level rise, on the other hand, is a separate phenomenon primarily caused by melting glaciers and thermal expansion of water due to rising ocean temperatures. [Source: NOAA Climate.gov and NOAA's National Ocean Service]. While both affect coastal areas, they are driven by different mechanisms.
