Does Pressure Keep the Deep Ocean From Freezing?

Summary

The video explores why pressure at the depths of the ocean, such as the Mariana Trench, does not prevent water from freezing. At 11 km deep, the pressure is about 1000 times greater than at the surface, which can lower the freezing point of water significantly. However, due to the salinity of seawater and various oceanic factors, deep ocean water typically remains between 0°C and 4°C. This prevents freezing, despite the increased pressure, as saltwater has a lower freezing point compared to freshwater. Overall, the interplay of pressure, salinity, and temperature keeps the deep ocean from freezing.

Takeaways

• 🌊 Pressure does not prevent the deep ocean from freezing.
• 📏 At the bottom of the Mariana Trench, the pressure is about 1000 times that of the atmosphere.
• ❄️ Ice can melt under high pressure; for instance, 500 times atmospheric pressure lowers the freezing point of fresh water to -4°C.
• 🔍 At 1000 times atmospheric pressure, saltwater can remain liquid down to approximately -11°C.
• 💧 The salinity of seawater affects its freezing point, allowing it to freeze at lower temperatures than fresh water.
• 🧊 Saltwater does not freeze until around -2°C on the ocean's surface.
• 📉 As pressure increases, the freezing point of saltwater decreases due to the unique properties of saline solutions.
• 🌡️ Deep ocean temperatures typically range from 0°C to 4°C, preventing freezing despite high pressure.
• 🔄 Various factors, including circulation and convection, help maintain these temperatures in deep ocean water.
• 🎓 The video includes a promotional segment for Brilliant.org, offering math and science courses with hands-on problem-solving.

Q & A

Does pressure prevent the deep ocean from freezing?

No, pressure does not prevent the deep ocean from freezing.

What is the pressure at the bottom of the Mariana Trench?

At the bottom of the Mariana Trench, the pressure is around 1000 times atmospheric pressure.

How does pressure affect the freezing point of ice?

Pressure can lower the freezing point of ice; for example, 500 times atmospheric pressure can melt ice at negative four degrees Celsius.

What temperature does salt water freeze at the ocean's surface?

At the ocean's surface, salt water does not freeze until around two degrees Celsius below zero.

What happens to the freezing point of salt water at 500 times atmospheric pressure?

At 500 times atmospheric pressure, salt water does not freeze until around six degrees Celsius below zero.

What is the freezing point of salt water at the bottom of the Mariana Trench?

At the bottom of the Mariana Trench, salt water would not freeze until around 11 degrees below zero.

Why does deep ocean water often remain liquid despite low temperatures?

Deep ocean water often remains around 0° to 4° Celsius due to factors like salinity and circulation, preventing it from getting much colder.

What role does salinity play in the freezing of ocean water?

Salinity shifts the freezing point of ocean water lower, allowing it to remain liquid at temperatures where freshwater would freeze.

How does deep ocean temperature relate to ice formation?

The deep ocean typically remains warm enough (around 0° to 2° Celsius below zero) due to salinity and pressure, which prevents ice formation.

What educational courses does the video sponsor, Brilliant.org, offer?

Brilliant.org offers math and science courses that include analyzing data and programming through hands-on problem solving.