Name the elements of the earth's magnetic field.

(N/A) The earth's magnetic field at any point on the surface is completely specified by three physical quantities, which are known as the elements of the earth's magnetic field:
$1$. Magnetic Declination $(\theta)$: The angle between the geographic meridian and the magnetic meridian at a place.
$2$. Magnetic Inclination or Angle of Dip $(\delta)$: The angle made by the total magnetic field vector of the earth with the horizontal direction in the magnetic meridian.
$3$. Horizontal Component of the Earth's Magnetic Field $(B_H)$: The component of the earth's total magnetic field vector along the horizontal direction in the magnetic meridian.