Question

Which of the following do you think (guess, know) best describes how pressure increases with depth in the ocean?

a - It increases linearly, with each 33 feet (10 m) of depth adding another 1 atm of pressure
b - It increases linearly, with each 3,300 feet (1,000 m) of depth adding another 1 atm of pressure
c - It increases exponentially, with each 33 feet (10 m) of depth doubling the total pressure
d - It increases exponentially, with each 3,300 feet (1,000 m) of depth doubling the total pressure

Answer 1

Pressure in the ocean increases linearly with depth; every 33 feet of depth adds 1 atm of pressure due to the weight of the water column, in addition to the 1 atm from the atmosphere.

Step-by-step explanation:

The increase in pressure with depth in the ocean best describes option a - It increases linearly, with each 33 feet (10 m) of depth adding another 1 atm of pressure. This is because the pressure due to a column of fluid is directly proportional to the height of the fluid column. At sea level, we experience 1 atmosphere (atm) of pressure from the air above us. As we descend into the ocean, we gain an additional 1 atm for every 33 feet (roughly 10 meters) of water above us, due to the weight of the water exerting pressure. Therefore, at a depth of 33 feet in seawater (which is approximately the same density throughout), the pressure is 2 atm; 1 atm from the water and 1 atm from the air above the water's surface as stated by Pascal's Principle, which affirms that fluid pressures always add in this way.