Introduction
Petroleum oil and natural gas are hydrocarbons that are found in the Earth's crust. These resources are important for energy production and are used in various industrial applications. However, the question arises as to why these resources are found above the water.
Formation of Petroleum Oil and Natural Gas
Petroleum oil and natural gas are formed from the remains of plants and animals that lived millions of years ago. These remains are buried under sedimentary rocks and are subjected to high temperatures and pressure, causing them to undergo a chemical process called diagenesis. This process converts the organic matter into hydrocarbons, which include petroleum oil and natural gas.
Movement of Hydrocarbons
Hydrocarbons are less dense than the rocks that surround them, and as a result, they tend to migrate upwards through the Earth's crust. However, the movement of hydrocarbons is not random, and it is guided by various factors, including:
- The presence of impermeable rocks that act as seals, preventing the hydrocarbons from escaping.
- The presence of porous rocks that act as reservoirs, allowing the hydrocarbons to accumulate.
- The presence of faults and fractures that provide pathways for the hydrocarbons to move upwards.
Location of the Earth's Crust
The Earth's crust is divided into two parts: the continental crust and the oceanic crust. The continental crust is thicker and less dense than the oceanic crust, and as a result, it tends to float higher above the mantle. This means that the continental crust is closer to the surface of the Earth, and it is more likely to contain hydrocarbon reserves.
Conclusion
In conclusion, petroleum oil and natural gas are found above the water because they are less dense than the rocks that surround them and tend to migrate upwards through the Earth's crust. The movement of hydrocarbons is guided by various factors, including the presence of impermeable rocks, porous rocks, and faults and fractures. Additionally, the location of the Earth's crust plays a role, as the continental crust is closer to the surface of the Earth and is more likely to contain hydrocarbon reserves.