The Dynamic Nature of Ocean Water Circulation

The belief that water at the bottom of the ocean remains there indefinitely is a common misconception. In reality, water in the ocean is part of a complex system of circulation known as thermohaline circulation, which plays a crucial role in regulating the Earth's climate and distributing vital nutrients.

Density Differences and Sinking

Water at the bottom of the ocean does not simply stay there. Instead, it is part of a dynamic system influenced by density differences. Cold, salty water is denser than warm, less salty water. In polar regions, water cools and becomes saltier as ice forms, causing it to sink. This sinking of dense, cold water sets in motion deep ocean currents that can remain at the bottom for hundreds to thousands of years.

Deep Ocean Currents and Upwelling

These deep currents eventually rise to the surface through a process called upwelling. Upwelling occurs where winds and currents converge to bring nutrient-rich water from the deep ocean back to the surface. This upwelling is essential for supporting marine biodiversity and provides a crucial source of nutrients for phytoplankton, the base of the ocean's food chain.

Mixing and Global Circulation

Surface waters are constantly mixed by wind and waves, which help distribute heat and nutrients throughout the ocean. This mixing, combined with deep ocean currents, forms part of a larger system of ocean circulation that helps regulate the Earth's climate and distribute heat.

The entire process of deep water sinking, traveling along the ocean floor, rising to the surface through upwelling, and being mixed by surface currents is a complex and interconnected system that spans the globe. This global circulation is essential for maintaining the health and productivity of the world's oceans.

Biological Productivity and Upwelling

Biological productivity in the oceans is significantly influenced by upwelling of bottom waters. The base of the food chain is plant life, which requires sunlight, water, nutrients, and a place to grow. However, sunlight only reaches a short distance into the water, with 99% absorbed by 150 meters. The limiting factor for plant life in the open ocean is “sh*t” that sinks, carrying nutrients away from the surface. Upwelling brings these nutrients back to the surface, enhancing the growth of phytoplankton and supporting a more productive ocean ecosystem.

The depth of mud on the ocean floor, known as ooze, is a direct result of this process. Near mid-ocean ridges where new crust is constantly forming, there is little sediment. However, the further away from these centers, the deeper the mud becomes, indicating that nutrients sink and are reused over time.

Harnessing Upwelling for Ocean Productivity

Increasing the biological productivity of the oceans could be achieved by creating artificial upwellings. This can be done through wind-driven pontoon trains that circulate in large circles, mimicking the natural upwelling process. This method is both feasible and sustainable, offering a practical solution to enhance the productivity of the open ocean.

In conclusion, while water at the bottom of the ocean can remain there for long periods, it is integral to a complex and dynamic system. Understanding and harnessing this system can lead to more productive and sustainable oceanic ecosystems.