NCERT Class 11 Geography — Chapter 2: Interior of the earth

mcqeasy

The deepest man-made borehole, located at Kola in the Arctic, reached a depth of:

Official previous-year question

Verified 1 Aug 2026.

Options

A12 km
B6,378 km
C100 km
D3-4 km

Did you get this right?

Solution

The correct option is 12 km.

Explanation

Knowledge about the interior of the Earth is derived from two types of sources: direct sources (such as mining and deep ocean drilling projects) and indirect sources (such as seismic waves, gravity anomalies, and meteors). The extent of direct exploration is limited by the rapid increase in temperature and pressure with depth.

Detailed Analysis:

Deepest Drilling Project: The deepest man-made borehole is the Kola Superdeep Borehole.
Location: It is located in the Kola Peninsula, Russia, within the Arctic region.
Depth: The drilling reached a depth of approximately 12 km.
Comparison with Earth's Dimensions:
- 3-4 km: This is the approximate depth of the deepest underground mines (e.g., gold mines in South Africa). Going beyond this depth is technically difficult due to extreme heat.
- 6,378 km: This represents the approximate equatorial radius of the Earth (distance to the center).

Consequently, while 12 km is a significant engineering achievement, it penetrates only a minute fraction of the Earth's crust compared to the planet's total radius.

Key Takeaway:

The deepest point reached by human drilling is the Kola borehole at 12 km, which provides direct evidence regarding the composition of the upper crust.

Your note

More from Chapter 2: Interior of the earth

With reference to 'Body Waves', consider the following statements: 1. They are generated due to the release of energy at the focus. 2. They move only in a vertical direction towards the surface. 3. They interact with surface rocks to generate surface waves. Which of the statements given above is/are correct?

easy

Which of the following statements is correct regarding the 'Shadow Zone' of P-waves?

medium

With reference to the 'Mantle', consider the following statements: 1. The lower mantle is in a liquid state. 2. It extends from Moho's discontinuity to a depth of 2,900 km. 3. It has a lower density than that of the crust. Which of the statements given above is/are correct?

medium

Consider the following statements regarding the 'Crust': 1. It is the innermost solid part of the earth. 2. It is brittle in nature. 3. Its thickness varies between oceanic and continental areas. Which of the statements given above is/are correct?

easy

With reference to the sources of information about the interior of the earth, consider the following statements: 1. Mining and drilling projects provide direct information about the earth's interior materials. 2. Meteors are considered a direct source of information because they originate from the earth's core. 3. Gravitation and magnetic fields are indirect sources of information. Which of the statements given above is/are correct?

medium

Keep practising Chapter 2: Interior of the earth

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The correct option is 12 km.

Explanation

Detailed Analysis:

Deepest Drilling Project: The deepest man-made borehole is the Kola Superdeep Borehole.
Location: It is located in the Kola Peninsula, Russia, within the Arctic region.
Depth: The drilling reached a depth of approximately 12 km.
Comparison with Earth's Dimensions:
- 3-4 km: This is the approximate depth of the deepest underground mines (e.g., gold mines in South Africa). Going beyond this depth is technically difficult due to extreme heat.
- 6,378 km: This represents the approximate equatorial radius of the Earth (distance to the center).

Consequently, while 12 km is a significant engineering achievement, it penetrates only a minute fraction of the Earth's crust compared to the planet's total radius.

Key Takeaway:

The deepest point reached by human drilling is the Kola borehole at 12 km, which provides direct evidence regarding the composition of the upper crust.