Question

Diurnal correction in magnetic survey data accounts for:

• A. geomagnetic polarity reversals
• B. charged particles in ionosphere
• C. the westward drift of the Earth’s magnetic field
• D. the lunar magnetic field

Hint:

Diurnal correction is applied to magnetic data to eliminate daily variations in the Earth's magnetic field caused by ionospheric currents affected by solar activity.

Answer 1

The Correct Option is B

Step 1: Understanding diurnal variations. The Earth’s magnetic field undergoes short-term fluctuations throughout the day due to changes in the ionosphere caused by solar radiation. 
Step 2: Purpose of diurnal correction. Magnetometers record total magnetic field, which can be influenced by these ionospheric variations. Diurnal correction removes these temporal effects to reveal local geological anomalies.