Understanding Topography, Geophysics, and Related Fields
Understanding Topography and Its Applications
Topography is the study of the methods needed to represent an area in full detail, whether natural or created by human hands. It also involves the knowledge and handling of instruments needed for this purpose.
Topometry
Topometry is the set of methods and operations related to the measurement of angles, distances, and gradients for locating the position of a point in space relative to some reference system.
Maps
A map is a flat representation of any part of the Earth’s surface. Due to the length and curvature of the planetary surface, special processing systems specific to mapping are required.
Types of Maps
- General
- Administrative
- Bathymetric
- Analytical
- Cadastral
- Qualitative
- Quantitative
Topographical Maps
A topographical map is a generally partial representation of the relief of the land surface at a defined scale. Topographic maps represent vast areas of territory. These include contour lines and other map resources that can reflect the shape of the Earth’s surface. The use of colors at various levels, along with other symbols and auxiliary lines, enables the recognition of mountains, valleys, rivers, hillocks, and other features of the terrain. It also includes information on human constructions. Topographical plans must indicate the scale, the direction of geographic and magnetic North, symbols, the relationship to other planes, the authoring agency, and the year of their preparation.
Plans
Plans are graphic representations of a limited extent of surface covered that do not require the use of cartographic systems. Unlike an elaborate map, it is not necessary to perform a projection. In the case of a plane, the curvature of the surface to be represented, due to its small size, is minimal, which makes projection unnecessary.
Geophysics: Studying the Earth
Geophysics is the science responsible for the study of the Earth from the viewpoint of physics. Its object of study covers all phenomena related to the structure, history, and physical conditions of the Earth. As an experimental discipline, it uses quantitative physical methods for its study. In some cases, these methods take advantage of fields or other natural phenomena induced by humans. Geophysics is the science whose aim is the scientific study of the Earth and its application to the search for natural resources, the reduction of effects caused by natural disasters, and environmental preservation.
Disciplines Related to Topography
Gravimetry
Gravimetry is the measurement of the gravitational field. It is often used when the object of study is the field of gravity or the density variations responsible for its variation.
Geomagnetism
Geomagnetism deals with the study of the Earth’s magnetic field, both its generation and its spatial and temporal variation.
Astronomy of Position
Astronomy of Position aims to study precise instruments and methods used in the direct determination of the geographical coordinates of certain points on the Earth’s surface through the observation of stars.
Astronomy-Geodesy
In geodesic astronomy or position astronomy, there is a field on whose surface all celestial bodies are projected, regardless of their distance. Its radius cannot be compared with the dimensions of the Earth.
- Topocentric systems: The center of the sphere coincides with the observer.
- Geocentric system: The center of the sphere coincides with the center of the Earth.
- Heliocentric system: The center of the sphere coincides with the center of the Sun.
Precession and Nutation
Precession is the change in the direction of the axis around which an object rotates. Nutation is the periodic oscillation of the pole of the Earth around its average position in the celestial sphere, due to the influence of the Moon on the planet. It is similar to the movement of a spinning top when it loses strength and is about to fall.
The Geoid
The Geoid is the actual shape of the Earth. It is an equipotential surface of gravity and corresponds to the representation of the average level of calm seas and oceans prolonged below the continents.