Earth's Magnetic Declination
DetailsPermalink to Details
- Added to the Catalog
- Available for
- Land: Magnetism
- Space: Earth's Magnetism
- Isogonic Lines
- Magnetic Declination
- Magnetic Field
- North Pole
- South Pole
- True North
DescriptionPermalink to Description
Earth is like a giant magnet with a North and South Pole. However, the magnetic North and South Pole are not aligned with the Geographic North and South Pole. The Geographic North Pole is defined by the latitude 90° N and is the axis of the Earth's rotation. The Magnetic North Pole is where the Earth's magnetic field points vertically downward. The Earth creates its own magnetic field from the electric currents created in the liquid iron-nickel core.
Compass needles point in the direction of the magnetic field lines, which is generally different from the direction to the Geographic North Pole. The compass pointing direction can also differ from the direction to the Magnetic North Pole since the magnetic field lines are not just circles connecting the magnetic poles. This dataset shows lines of equal magnetic declination (isogonic lines) measured in degrees east (positive) or west (negative) of True North. The green line is where the declination equals zero and the direction of True North and Magnetic North are equal (agonic line). The Magnetic North and South Poles are indicated by the green circles. It is important to know the magnetic declination when using a compass to navigate so that the direction of True North can be determined. Since the 1970's, the movement of the Magnetic North Pole has accelerated, which is noticeable in this dataset.
In this figure and animation, the magnetic field from 1590 to 1890 is given by the GUFM-1 model of Jackson et al. (2000), while the field from 1900 to 2025 is given by the 13th generation of the International Geomagnetic Reference Field. Between 1890 and 1900, a smooth transition was imposed between the models. This visualization uses a transverse aspect of the Plate Carée projection to minimize distortion near the poles.
Next Generation Science StandardsPermalink to Next Generation Science Standards
Cross-cutting ConceptsPermalink to Cross-cutting Concepts
C1 Patterns. Students recognize that macroscopic patterns are related to the nature of microscopic and atomic-level structure. They identify patterns in rates of change and other numerical relationships that provide information about natural and human designed systems. They use patterns to identify cause and effect relationships, and use graphs and charts to identify patterns in data.
C3 Scale Proportion and Quantity. Students observe time, space, and energy phenomena at various scales using models to study systems that are too large or too small. They understand phenomena observed at one scale may not be observable at another scale, and the function of natural and designed systems may change with scale. They use proportional relationships (e.g., speed as the ratio of distance traveled to time taken) to gather information about the magnitude of properties and processes. They represent scientific relationships through the use of algebraic expressions and equations
C4 Systems and System Models. Students can understand that systems may interact with other systems; they may have sub-systems and be a part of larger complex systems. They can use models to represent systems and their interactions—such as inputs, processes and outputs—and energy, matter, and information flows within systems. They can also learn that models are limited in that they only represent certain aspects of the system under study.
C5 Energy and Matter. Students learn matter is conserved because atoms are conserved in physical and chemical processes. They also learn within a natural or designed system, the transfer of energy drives the motion and/or cycling of matter. Energy may take different forms (e.g. energy in fields, thermal energy, energy of motion). The transfer of energy can be tracked as energy flows through a designed or natural system.
C7 Stability and Change. Students explain stability and change in natural or designed systems by examining changes over time, and considering forces at different scales, including the atomic scale. Students learn changes in one part of a system might cause large changes in another part, systems in dynamic equilibrium are stable due to a balance of feedback mechanisms, and stability might be disturbed by either sudden events or gradual changes that accumulate over time
C2 Cause and Effect. Students understand that empirical evidence is required to differentiate between cause and correlation and to make claims about specific causes and effects. They suggest cause and effect relationships to explain and predict behaviors in complex natural and designed systems. They also propose causal relationships by examining what is known about smaller scale mechanisms within the system. They recognize changes in systems may have various causes that may not have equal effects.
C4 Systems and System Models. Students can investigate or analyze a system by defining its boundaries and initial conditions, as well as its inputs and outputs. They can use models (e.g., physical, mathematical, computer models) to simulate the flow of energy, matter, and interactions within and between systems at different scales. They can also use models and simulations to predict the behavior of a system, and recognize that these predictions have limited precision and reliability due to the assumptions and approximations inherent in the models. They can also design systems to do specific tasks.
C5 Energy and Matter. Students learn that the total amount of energy and matter in closed systems is conserved. They can describe changes of energy and matter in a system in terms of energy and matter flows into, out of, and within that system. They also learn that energy cannot be created or destroyed. It only moves between one place and another place, between objects and/or fields, or between systems. Energy drives the cycling of matter within and between systems. In nuclear processes, atoms are not conserved, but the total number of protons plus neutrons is conserved.
C7 Stability and Change. Students understand much of science deals with constructing explanations of how things change and how they remain stable. They quantify and model changes in systems over very short or very long periods of time. They see some changes are irreversible, and negative feedback can stabilize a system, while positive feedback can destabilize it. They recognize systems can be designed for greater or lesser stability
Disciplinary Core IdeasPermalink to Disciplinary Core Ideas
ESS1.C The History of Planet Earth. Rock strata and the fossil record can be used as evidence to organize the relative occurrence of major historical events in Earth’s history.
ESS2.A Earth Materials and Systems. Energy flows and matter cycles within and among Earth’s systems, including the sun and Earth’s interior as primary energy sources. Plate tectonics is one result of these processes.
PS2.B Types of Interactions. Forces that act at a distance involve fields that can be mapped by their relative strength and effect on an object.
PS3.B Conservation of Energy and Energy Transfer. Kinetic energy can be distinguished from the various forms of potential energy. Energy changes to and from each type can be tracked through physical or chemical interactions. The relationship between the temperature and the total energy of a system depends on the types, states, and amounts of matter.
PS3.C Relationship between energy and forces. When two objects interact, each one exerts a force on the other, and these forces can transfer energy between them.
ESS1.C The History of Planet Earth. The rock record resulting from tectonic and other geoscience processes as well as objects from the solar system can provide evidence of Earth’s early history and the relative ages of major geologic formations.
ESS2.A Earth Materials and Systems. Feedback effects exist within and among Earth’s systems.The geological record shows that changes to global and regional climate can be caused by interactions among changes in the sun’s energy output or Earth’s orbit, tectonic events, ocean circulation, volcanic activity, glaciers, vegetation, and human activities.
PS2.B Types of Interactions. Forces at a distance are explained by fields that can transfer energy and can be described in terms of the arrangement and properties of the interacting objects and the distance between them. These forces can be used to describe the relationship between electrical and magnetic fields.
PS3.B Conservation of Energy and Energy Transfer. Systems move toward stable states.
PS3.C Relationship between energy and forces. Fields contain energy that depends on the arrangement of the objects in the field.
PS4.B Electromagnetic Radiation. Both an electromagnetic wave model and a photon model explain features of electromagnetic radiation broadly and describe common applications of electromagnetic radiation.
Notable FeaturesPermalink to Notable Features
- The magnetic poles (indicated by green circles) slowly move with time
- The magnetic declination varies with time due to changes of the Earth's magnetic field
- Since the 1970's the Magnetic North Pole has accelerated from less than 10 to more than 30 miles per year
Data SourcePermalink to Data Source
NOAA National Centers for Environmental Information (NCEI)