Question

The lithostatic pressure at a depth of 36.5 km in the continental crust having an average density of 2800 $kg/m^3$, is _____ GPa. (Round off to the nearest integer) (Use g = 9.8 $m/s^2$)

Answer 1

Correct Answer: 1

Calculating the Lithostatic Pressure 

Step 1: Understanding the Formula

The lithostatic pressure (P) can be calculated using the formula:

\[ P = \rho \cdot g \cdot h \]

Where:

• P is the lithostatic pressure.
• \(\rho\) is the density of the rock (2800 kg/m³).
• g is the acceleration due to gravity (9.8 m/s²).
• h is the depth (36.5 km = 36,500 m).

Step 2: Substituting the Given Values

Substituting the given values into the formula:

\[ P = 2800 \, \text{kg/m}^3 \times 9.8 \, \text{m/s}^2 \times 36,500 \, \text{m} = 1.0 \times 10^9 \, \text{Pa} \]

Step 3: Convert Pascals to Gigapascals (GPa)

To convert from Pascals to Gigapascals (GPa), divide by \( 10^9 \):

\[ P = 1.0 \, \text{GPa} \]

Final Answer:

The lithostatic pressure is: 1 GPa.