What is Transgression?
Transgression is a natural process that involves the rising of water level in the oceans. In simple words, the intervention of glaciers and rains contribute to raising the water level in the oceans. It can be divided into two types. It is important to explain its types so you can understand the process in detail.
Holocene transgression occurs when the glaciers melt globally, and the water level starts to increase. The worldwide melting of glaciers has changed geographical maps and the world’s natural landscape in different ways. However, these events happen rarely; the last happened 11,700 years ago. It caused the ice sheets of North America and Europe to melt completely.
Marine transgression is a natural process and happens when the sea level keeps rising compared to the land. The process of comparing a higher sea level with respect to land is called transgression.
A common example is the Western Interior Seaway that leads from the Gulf of Mexico to the Arctic Ocean. The seaway is formed as a result of the continuous rising in the sea level.
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Transgression VS Regression
Transgression happens when the water level in ocean basins goes beyond its capacity or when the land starts sinking into the sea. It often results in a flood. This particular flood is known as transgression. Regression is the opposite of transgression. It happens when the water level in the ocean basin goes beyond its capacity, resulting in exposure to land previously covered by the sea. Regression changes are always horizontal.
The best example of regression is the Bering Land Bridge between Asia and Alaska. Sahara, one of the largest deserts in the world, was also created due to regression.
Transgression usually happens due to the following reasons.
- Sliding/melting glaciers and melting icecaps
- Deposition and rock-forming
- Heavy and continuous rains
Regression can occur as a result of the following.
- No rainfall
- Increase in temperature
- Increase in land mass due to earthquakes or tectonic plate movement
- A buildup of icebergs in the polar ice caps
- It makes land fertile by bringing soil from fertile valleys
- Transgression sometimes forms new islands
- Sweater delivers precious marine treasures like gems and pearls to coastal areas.