Angle of Dip

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What is Angle of Dip?

The angle of dip is also sometimes called the magnetic dip and is defined as the angle which is made by the earth’s magnetic field lines with the horizontal.

The angle of dip usually is said it varies from point to point by providing the information which is related to the movement of the earth’s magnetic field.  The angle of dip is said to be positive when the magnetic field points in the direction that is downwards. When the magnetic field points towards upward direction then the angle of dip is said to be negative.

The angle of dip is 0° when the needle of the dip rests horizontally while the angle of dip is 90° when the needle of dip rests vertically.

When the component that is horizontal and the vertical component of the earth’s magnetic field are equal the angle of dip is equal to 45°.


Magnetic Dip

Geomagnetics is that branch of geophysics concerned with all aspects of the magnetic field which is of earth’s that is including its origin, variation through time and manifestations in the form of magnetic poles. The remnant of the magnetization of rocks and local or the regional magnetic anomalies. The latter generally reflects the difference which is between theoretical and observed magnetic intensities at points of measurement with a magnetometer. When plotted on a magnetic map, it is known as an aeromagnetic map if the magnetometer was flown across the area. The anomalies provide the basis for inferences that is about probable subsurface structure and composition.

The magnetic dip or the dip angle or the magnetic inclination is the angle made with the horizontal by the line of the earth's magnetic field. This angle generally varies at different points on the surface of the earth. The positive values of inclination indicate that the earth's magnetic field is pointing downward into the Earth that too at the point of measurement. And the value if, negative indicates that it is pointing upward. The dip angle is said to be in principle the angle which is made by the needle of a vertically held compass. In practice, ordinary compass needles may be weighted against dip or may be unable to move freely in the correct plane. The value of it can be measured even more reliably with a special instrument typically called a dip circle.

In 1544 the angle which is the dip was discovered by the engineer Georg Hartmann. A method which measures it with a circle of dip was described by Robert Norman in England in 1581.


Magnetic Inclination

Magnetic dip results from the tendency of a magnet to align itself with lines of the magnetic field. As the planet's magnetic field lines are not parallel to the surface, the northern end of a compass needle will point downward. That is in the northern hemisphere it is positive dip or upward while in the southern hemisphere it is a negative dip. The range of dip is from -90 degrees at the North Magnetic Pole to +90 degrees at the South Magnetic Pole. The contour lines along which the dip measured at the planet's surface is equal are referred to as isoclinic lines. The points locus which is having a zero dip is known as the magnetic equator or aclinic line.

The dip angle which is also called magnetic dip or magnetic Inclination is the angle made by our planet's magnetic field lines with the horizontal. The angle of dip generally varies from point to point at the surface of the earth and provides information about the movement of the earth’s magnetic field. 

The phenomenon is especially very much important in aviation as it causes the compass of the airplane to give erroneous readings during banked turns and airspeed changes. The latter errors generally occur because the card of compass tilts on its mount when under acceleration.

The needle compasses are often weighed during manufacture to compensate for magnetic dip so we can say that they will balance roughly horizontally. This balancing is usually said to be latitude-dependent.


FAQ (Frequently Asked Questions)

1. What is the angle of dip and declination?

The angle of declination is said to be the angle which is between the geographical meridian and the magnetic meridian at a place. It is also known as the magnetic declination at that place. 

The angle of dip is the angle made by the earth's total magnetic field denoted as B→ with the horizontal direction in the magnetic meridian, known as the angle of dip (δ) at any place.

2. What is the use of the angle of dip?

The angle which is the dip angle or the magnetic dip is the angle that earth's magnetic field makes with the horizontal at any given geographical location. The dip angle is used for measuring as well as correcting the magnetic compass error. It also has its uses in the field of geology and in mapping.

3. Where is the angle of dip 90?

The range of dip angle is from -90 degrees at the North Magnetic Pole to +90 degrees at the South Magnetic Pole. The contour lines along which the dip is measured at the surface of Earth is referred to as isoclinic lines. The locus of the points having a zero dip is known as the magnetic equator or aclinic line.

4. Explain why the angle of declination changes?

This angle generally is said to be depending on the position on the surface of Earth's and changes over time. The angle which is between magnetic and grid meridians is known as the grid magnetic angle or the grid variation. By convention, we can say that the declination is positive when magnetic north is east of true north and negative when it is to the west.