Misplaced Pages

#456543

76-521: Paleomaps are maps of continents and mountain ranges in the past based on plate reconstructions . Until the 1960s, paleomaps were not very satisfactory, since it was difficult to understand many quite distinctive features. For example, huge river deltas seemed to be associated with what must have been rather small drainage basins. With the discovery of plate tectonics , it became apparent that land masses move relative to one another over time. Ancient geologic features started to make far more sense. It

152-436: A choropleth map . In meteorology, the word isopleth is used for any type of contour line. Meteorological contour lines are based on interpolation of the point data received from weather stations and weather satellites . Weather stations are seldom exactly positioned at a contour line (when they are, this indicates a measurement precisely equal to the value of the contour). Instead, lines are drawn to best approximate

228-516: A map legend on the margin of the map, or on a separately published characteristic sheet. Some cartographers prefer to make the map cover practically the entire screen or sheet of paper, leaving no room "outside" the map for information about the map as a whole. These cartographers typically place such information in an otherwise "blank" region "inside" the map— cartouche , map legend, title, compass rose , bar scale , etc. In particular, some maps contain smaller maps inset into otherwise blank areas of

304-450: A ratio , such as 1:10,000, which means that 1 unit of measurement on the map corresponds to 10,000 of that same unit on the ground. The scale statement can be accurate when the region mapped is small enough for the curvature of the Earth to be neglected, such as a city map . Mapping larger regions, where the curvature cannot be ignored, requires projections to map from the curved surface of

380-691: A word without a repeated letter . As late as 1944, John K. Wright still preferred isogram , but it never attained wide usage. During the early 20th century, isopleth ( πλῆθος , plethos , 'amount') was being used by 1911 in the United States, while isarithm ( ἀριθμός , arithmos , 'number') had become common in Europe. Additional alternatives, including the Greek-English hybrid isoline and isometric line ( μέτρον , metron , 'measure'), also emerged. Despite attempts to select

456-401: A "contour") joins points of equal elevation (height) above a given level, such as mean sea level . A contour map is a map illustrated with contour lines, for example a topographic map , which thus shows valleys and hills, and the steepness or gentleness of slopes. The contour interval of a contour map is the difference in elevation between successive contour lines. The gradient of

532-464: A broad understanding of the location and features of an area. The reader may gain an understanding of the type of landscape, the location of urban places, and the location of major transportation routes all at once. Polish general Stanisław Maczek had once been shown an impressive outdoor map of land and water in the Netherlands demonstrating the working of the waterways (which had been an obstacle to

608-654: A chart of magnetic variation. The Dutch engineer Nicholas Cruquius drew the bed of the river Merwede with lines of equal depth (isobaths) at intervals of 1 fathom in 1727, and Philippe Buache used them at 10-fathom intervals on a chart of the English Channel that was prepared in 1737 and published in 1752. Such lines were used to describe a land surface (contour lines) in a map of the Duchy of Modena and Reggio by Domenico Vandelli in 1746, and they were studied theoretically by Ducarla in 1771, and Charles Hutton used them in

684-411: A constant pressure surface chart. Isohypse and isoheight are simply known as lines showing equal pressure on a map. An isotherm (from Ancient Greek θέρμη (thermē)  'heat') is a line that connects points on a map that have the same temperature . Therefore, all points through which an isotherm passes have the same or equal temperatures at the time indicated. An isotherm at 0 °C

760-407: A curve of constant electric potential . Whether crossing an equipotential line represents ascending or descending the potential is inferred from the labels on the charges. In three dimensions, equipotential surfaces may be depicted with a two dimensional cross-section, showing equipotential lines at the intersection of the surfaces and the cross-section. The general mathematical term level set

836-431: A given location and is used in the generation of isochrone maps . An isotim shows equivalent transport costs from the source of a raw material, and an isodapane shows equivalent cost of travel time. Contour lines are also used to display non-geographic information in economics. Indifference curves (as shown at left) are used to show bundles of goods to which a person would assign equal utility. An isoquant (in

SECTION 10

#1732887155457

912-828: A line of constant annual variation of magnetic declination . An isoclinic line connects points of equal magnetic dip , and an aclinic line is the isoclinic line of magnetic dip zero. An isodynamic line (from δύναμις or dynamis meaning 'power') connects points with the same intensity of magnetic force. Besides ocean depth, oceanographers use contour to describe diffuse variable phenomena much as meteorologists do with atmospheric phenomena. In particular, isobathytherms are lines showing depths of water with equal temperature, isohalines show lines of equal ocean salinity, and isopycnals are surfaces of equal water density. Various geological data are rendered as contour maps in structural geology , sedimentology , stratigraphy and economic geology . Contour maps are used to show

988-464: A map may be fixed to paper or other durable media, or may be displayed on a transitory medium such as a computer screen. Some maps change interactively. Although maps are commonly used to depict geographic elements , they may represent any space, real or fictional. The subject being mapped may be two-dimensional such as Earth's surface, three-dimensional such as Earth's interior, or from an abstract space of any dimension. Maps of geographic territory have

1064-399: A particular purpose for an intended audience. Designing a map involves bringing together a number of elements and making a large number of decisions. The elements of design fall into several broad topics, each of which has its own theory, its own research agenda, and its own best practices. That said, there are synergistic effects between these elements, meaning that the overall design process

1140-426: A picture of the major thermodynamic factors in a weather system. An isobar (from Ancient Greek βάρος (baros)  'weight') is a line of equal or constant pressure on a graph, plot, or map; an isopleth or contour line of pressure. More accurately, isobars are lines drawn on a map joining places of equal average atmospheric pressure reduced to sea level for a specified period of time. In meteorology ,

1216-440: A point; this distinction has since been followed generally. An example of an isopleth is population density , which can be calculated by dividing the population of a census district by the surface area of that district. Each calculated value is presumed to be the value of the variable at the centre of the area, and isopleths can then be drawn by a process of interpolation . The idea of an isopleth map can be compared with that of

1292-489: A single standard, all of these alternatives have survived to the present. When maps with contour lines became common, the idea spread to other applications. Perhaps the latest to develop are air quality and noise pollution contour maps, which first appeared in the United States in approximately 1970, largely as a result of national legislation requiring spatial delineation of these parameters. Contour lines are often given specific names beginning with " iso- " according to

1368-421: A specific time interval, and katallobars , lines joining points of equal pressure decrease. In general, weather systems move along an axis joining high and low isallobaric centers. Isallobaric gradients are important components of the wind as they increase or decrease the geostrophic wind . An isopycnal is a line of constant density. An isoheight or isohypse is a line of constant geopotential height on

1444-461: A variety of scales, from large-scale engineering drawings and architectural plans, through topographic maps and bathymetric charts , up to continental-scale maps. "Contour line" is the most common usage in cartography , but isobath for underwater depths on bathymetric maps and isohypse for elevations are also used. In cartography, the contour interval is the elevation difference between adjacent contour lines. The contour interval should be

1520-417: A very long tradition and have existed from ancient times. The word "map" comes from the medieval Latin : Mappa mundi , wherein mappa meant 'napkin' or 'cloth' and mundi 'of the world'. Thus, "map" became a shortened term referring to a flat representation of Earth's surface. Maps have been one of the most important human inventions for millennia, allowing humans to explain and navigate their way through

1596-446: Is a contour line for a variable which measures direction. In meteorology and in geomagnetics, the term isogon has specific meanings which are described below. An isocline ( κλίνειν , klinein , 'to lean or slope') is a line joining points with equal slope. In population dynamics and in geomagnetics, the terms isocline and isoclinic line have specific meanings which are described below. A curve of equidistant points

SECTION 20

#1732887155457

1672-452: Is a line joining points with constant wind speed. In meteorology, the term isogon refers to a line of constant wind direction. An isopectic line denotes equal dates of ice formation each winter, and an isotac denotes equal dates of thawing. Contours are one of several common methods used to denote elevation or altitude and depth on maps . From these contours, a sense of the general terrain can be determined. They are used at

1748-438: Is a line of equal or constant dew point . An isoneph is a line indicating equal cloud cover. An isochalaz is a line of constant frequency of hail storms, and an isobront is a line drawn through geographical points at which a given phase of thunderstorm activity occurred simultaneously. Snow cover is frequently shown as a contour-line map. An isotach (from Ancient Greek ταχύς (tachus)  'fast')

1824-470: Is a line of equal temperature beneath the Earth's surface. An isohyet or isohyetal line (from Ancient Greek ὑετός (huetos)  'rain') is a line on a map joining points of equal rainfall in a given period. A map with isohyets is called an isohyetal map . An isohume is a line of constant relative humidity , while an isodrosotherm (from Ancient Greek δρόσος (drosos)  'dew' and θέρμη (therme)  'heat')

1900-485: Is a set of points all at the same distance from a given point , line , or polyline . In this case the function whose value is being held constant along a contour line is a distance function . In 1944, John K. Wright proposed that the term isopleth be used for contour lines that depict a variable which cannot be measured at a point, but which instead must be calculated from data collected over an area, as opposed to isometric lines for variables that could be measured at

1976-510: Is called a cartographer . Road maps are perhaps the most widely used maps today. They are a subset of navigational maps, which also include aeronautical and nautical charts , railroad network maps, and hiking and bicycling maps. In terms of quantity, the largest number of drawn map sheets is probably made up by local surveys, carried out by municipalities , utilities, tax assessors, emergency services providers, and other local agencies. Many national surveying projects have been carried out by

2052-602: Is called the freezing level . The term lignes isothermes (or lignes d'égale chaleur) was coined by the Prussian geographer and naturalist Alexander von Humboldt , who as part of his research into the geographical distribution of plants published the first map of isotherms in Paris, in 1817. According to Thomas Hankins, the Scottish engineer William Playfair 's graphical developments greatly influenced Alexander von Humbolt's invention of

2128-456: Is derived from Latin oriens , meaning east. In the Middle Ages many maps, including the T and O maps , were drawn with east at the top (meaning that the direction "up" on the map corresponds to East on the compass). The most common cartographic convention nowadays is that north is at the top of a map. Maps not oriented with north at the top: Many maps are drawn to a scale expressed as

2204-508: Is especially important in riparian zones. An isoflor is an isopleth contour connecting areas of comparable biological diversity. Usually, the variable is the number of species of a given genus or family that occurs in a region. Isoflor maps are thus used to show distribution patterns and trends such as centres of diversity. In economics , contour lines can be used to describe features which vary quantitatively over space. An isochrone shows lines of equivalent drive time or travel time to

2280-454: Is indicated on maps with isoplats . Some of the most widespread applications of environmental science contour maps involve mapping of environmental noise (where lines of equal sound pressure level are denoted isobels ), air pollution , soil contamination , thermal pollution and groundwater contamination. By contour planting and contour ploughing , the rate of water runoff and thus soil erosion can be substantially reduced; this

2356-588: Is not just working on each element one at a time, but an iterative feedback process of adjusting each to achieve the desired gestalt . Maps of the world or large areas are often either 'political' or 'physical'. The most important purpose of the political map is to show territorial borders ; the purpose of the physical map is to show features of geography such as mountains, soil type, or land use including infrastructures such as roads, railroads, and buildings. Topographic maps show elevations and relief with contour lines or shading. Geological maps show not only

Paleomap - Misplaced Pages Continue

2432-606: Is now possible to construct maps that are probably fairly accurate for continental positions over several hundred million years. Before the Cambrian Period, it becomes much more difficult since there are fewer rock exposures preserved. The state of large regions of the Earth becomes unknowable in the distant past. Where rocks are exposed, latitudes can often be determined from the orientation of preserved magnetic fields (see paleomagnetism ) but longitudes are based on projections that are increasingly uncertain as one gets further from

2508-466: Is often used to describe the full collection of points having a particular potential, especially in higher dimensional space. In the study of the Earth's magnetic field , the term isogon or isogonic line refers to a line of constant magnetic declination , the variation of magnetic north from geographic north. An agonic line is drawn through points of zero magnetic declination. An isoporic line refers to

2584-412: Is shown in all areas. Conversely, for an island which consists of a plateau surrounded by steep cliffs, it is possible to use smaller intervals as the height increases. An isopotential map is a measure of electrostatic potential in space, often depicted in two dimensions with the electrostatic charges inducing that electric potential . The term equipotential line or isopotential line refers to

2660-467: Is used by agencies around the world, as diverse as wildlife conservationists and militaries. Even when GIS is not involved, most cartographers now use a variety of computer graphics programs to generate new maps. Interactive, computerized maps are commercially available, allowing users to zoom in or zoom out (respectively meaning to increase or decrease the scale), sometimes by replacing one map with another of different scale, centered where possible on

2736-964: The Schiehallion experiment . In 1791, a map of France by J. L. Dupain-Triel used contour lines at 20-metre intervals, hachures, spot-heights and a vertical section. In 1801, the chief of the French Corps of Engineers, Haxo , used contour lines at the larger scale of 1:500 on a plan of his projects for Rocca d'Anfo , now in northern Italy, under Napoleon . By around 1843, when the Ordnance Survey started to regularly record contour lines in Great Britain and Ireland , they were already in general use in European countries. Isobaths were not routinely used on nautical charts until those of Russia from 1834, and those of Britain from 1838. As different uses of

2812-514: The barometric pressures shown are reduced to sea level , not the surface pressures at the map locations. The distribution of isobars is closely related to the magnitude and direction of the wind field, and can be used to predict future weather patterns. Isobars are commonly used in television weather reporting. Isallobars are lines joining points of equal pressure change during a specific time interval. These can be divided into anallobars , lines joining points of equal pressure increase during

2888-425: The geoid to a two-dimensional picture. Projection always distorts the surface. There are many ways to apportion the distortion, and so there are many map projections. Which projection to use depends on the purpose of the map. The various features shown on a map are represented by conventional signs or symbols. For example, colors can be used to indicate a classification of roads. Those signs are usually explained in

2964-681: The British Columbia Pavilion at the Pacific National Exhibition (PNE) in Vancouver from 1954 to 1997 it was viewed by millions of visitors. The Guinness Book of Records cites the Challenger Map as the largest of its kind in the world. The map in its entirety occupies 6,080 square feet (1,850 square metres) of space. It was disassembled in 1997; there is a project to restore it in a new location. The Relief map of Guatemala

3040-453: The Earth to the plane. The impossibility of flattening the sphere to the plane without distortion means that the map cannot have a constant scale. Rather, on most projections, the best that can be attained is an accurate scale along one or two paths on the projection. Because scale differs everywhere, it can only be measured meaningfully as point scale per location. Most maps strive to keep point scale variation within narrow bounds. Although

3116-462: The Polish forces progress in 1944). This had inspired Maczek and his companions to create Great Polish Map of Scotland as a 70-ton permanent three-dimensional reminder of Scotland's hospitality to his compatriots. In 1974, the coastline and relief of Scotland were laid out by Kazimierz Trafas, a Polish student geographer-planner, based on existing Bartholomew Half-Inch map sheets. Engineering infrastructure

Paleomap - Misplaced Pages Continue

3192-452: The below ground surface of geologic strata , fault surfaces (especially low angle thrust faults ) and unconformities . Isopach maps use isopachs (lines of equal thickness) to illustrate variations in thickness of geologic units. In discussing pollution, density maps can be very useful in indicating sources and areas of greatest contamination. Contour maps are especially useful for diffuse forms or scales of pollution. Acid precipitation

3268-520: The connectivity is significant. The London Underground map and similar subway maps around the world are a common example of these maps. General-purpose maps provide many types of information on one map. Most atlas maps, wall maps, and road maps fall into this category. The following are some features that might be shown on general-purpose maps: bodies of water, roads, railway lines, parks, elevations, towns and cities, political boundaries, latitude and longitude, national and provincial parks. These maps give

3344-549: The dates of onset of a given phenomenon (for example, the first frost and appearance or disappearance of the snow cover) or the date of a particular value of a meteorological element in the course of a year (for example, passing of the mean daily air temperature through zero). Isolines of the mean numerical value of wind velocity or isotachs are drawn on wind maps (charts); the wind resultants and directions of prevailing winds are indicated by arrows of different lengths or arrows with different plumes; lines of flow are often drawn. Maps of

3420-445: The differences between the mean temperatures of the warmest and coldest month). Isanomals are drawn on maps of anomalies (for example, deviations of the mean temperature of each place from the mean temperature of the entire latitudinal zone). Isolines of frequency are drawn on maps showing the frequency of a particular phenomenon (for example, the annual number of days with a thunderstorm or snow cover). Isochrones are drawn on maps showing

3496-405: The distribution of pressure at different standard altitudes—for example, at every kilometer above sea level—or by maps of baric topography on which altitudes (more precisely geopotentials) of the main isobaric surfaces (for example, 900, 800, and 700 millibars) counted off from sea level are plotted. The temperature, humidity, and wind on aero climatic maps may apply either to standard altitudes or to

3572-435: The earth's surface and in the upper layers of the atmosphere. Climatic maps show climatic features across a large region and permit values of climatic features to be compared in different parts of the region. When generating the map, spatial interpolation can be used to synthesize values where there are no measurements, under the assumption that conditions change smoothly. Climatic maps generally apply to individual months and

3648-476: The earth's surface into climatic zones and regions according to some classification of climates, are a special kind of climatic map. Climatic maps are often incorporated into climatic atlases of varying geographic ranges (globe, hemispheres, continents, countries, oceans) or included in comprehensive atlases. Besides general climatic maps, applied climatic maps and atlases have great practical value. Aero climatic maps, aero climatic atlases, and agro climatic maps are

3724-428: The edges of the map. Further inaccuracies may be deliberate. For example, cartographers may simply omit military installations or remove features solely to enhance the clarity of the map. For example, a road map may not show railroads, smaller waterways, or other prominent non-road objects, and even if it does, it may show them less clearly (e.g. dashed or dotted lines/outlines) than the main roads. Known as decluttering,

3800-487: The function is always perpendicular to the contour lines. When the lines are close together the magnitude of the gradient is large: the variation is steep. A level set is a generalization of a contour line for functions of any number of variables. Contour lines are curved, straight or a mixture of both lines on a map describing the intersection of a real or hypothetical surface with one or more horizontal planes. The configuration of these contours allows map readers to infer

3876-452: The image at right) is a curve of equal production quantity for alternative combinations of input usages , and an isocost curve (also in the image at right) shows alternative usages having equal production costs. In political science an analogous method is used in understanding coalitions (for example the diagram in Laver and Shepsle's work ). In population dynamics , an isocline shows

SECTION 50

#1732887155457

3952-429: The isotherm. Humbolt later used his visualizations and analyses to contradict theories by Kant and other Enlightenment thinkers that non-Europeans were inferior due to their climate. An isocheim is a line of equal mean winter temperature, and an isothere is a line of equal mean summer temperature. An isohel ( ἥλιος , helios , 'Sun') is a line of equal or constant solar radiation . An isogeotherm

4028-440: The latter case, the method of interpolation affects the reliability of individual isolines and their portrayal of slope , pits and peaks. The idea of lines that join points of equal value was rediscovered several times. The oldest known isobath (contour line of constant depth) is found on a map dated 1584 of the river Spaarne , near Haarlem , by Dutchman Pieter Bruinsz. In 1701, Edmond Halley used such lines (isogons) on

4104-474: The left) of Europe has been distorted to show population distribution, while the rough shape of the continent is still discernible. Another example of distorted scale is the famous London Underground map . The geographic structure is respected but the tube lines (and the River Thames ) are smoothed to clarify the relationships between stations. Near the center of the map, stations are spaced out more than near

4180-442: The locations of exact values, based on the scattered information points available. Meteorological contour maps may present collected data such as actual air pressure at a given time, or generalized data such as average pressure over a period of time, or forecast data such as predicted air pressure at some point in the future. Thermodynamic diagrams use multiple overlapping contour sets (including isobars and isotherms) to present

4256-458: The main isobaric surfaces. Isolines are drawn on maps of such climatic features as the long-term mean values (of atmospheric pressure, temperature, humidity, total precipitation, and so forth) to connect points with equal values of the feature in question—for example, isobars for pressure, isotherms for temperature, and isohyets for precipitation. Isoamplitudes are drawn on maps of amplitudes (for example, annual amplitudes of air temperature—that is,

4332-427: The map key. Usually contour intervals are consistent throughout a map, but there are exceptions. Sometimes intermediate contours are present in flatter areas; these can be dashed or dotted lines at half the noted contour interval. When contours are used with hypsometric tints on a small-scale map that includes mountains and flatter low-lying areas, it is common to have smaller intervals at lower elevations so that detail

4408-462: The map: for example: The design and production of maps is a craft that has developed over thousands of years, from clay tablets to Geographic information systems . As a form of Design , particularly closely related to Graphic design , map making incorporates scientific knowledge about how maps are used, integrated with principles of artistic expression, to create an aesthetically attractive product, carries an aura of authority, and functionally serves

4484-511: The military, such as the British Ordnance Survey : a civilian government agency, internationally renowned for its comprehensively detailed work. The location information showed by maps may include contour lines , indicating constant values of elevation , temperature, rainfall, etc. The orientation of a map is the relationship between the directions on the map and the corresponding compass directions in reality. The word " orient "

4560-569: The most numerous. Maps exist of the Solar System , and other cosmological features such as star maps . In addition maps of other bodies such as the Moon and other planets are technically not geo graphical maps. Floor maps are also spatial but not necessarily geospatial. Diagrams such as schematic diagrams and Gantt charts and tree maps display logical relationships between items, rather than geographic relationships. Topological in nature, only

4636-482: The nature of the variable being mapped, although in many usages the phrase "contour line" is most commonly used. Specific names are most common in meteorology, where multiple maps with different variables may be viewed simultaneously. The prefix "' iso- " can be replaced with " isallo- " to specify a contour line connecting points where a variable changes at the same rate during a given time period. An isogon (from Ancient Greek γωνία (gonia)  'angle')

SECTION 60

#1732887155457

4712-429: The physical surface, but characteristics of the underlying rock, fault lines, and subsurface structures. From the last quarter of the 20th century, the indispensable tool of the cartographer has been the computer. Much of cartography, especially at the data-gathering survey level, has been subsumed by geographic information systems (GIS). The functionality of maps has been greatly advanced by technology simplifying

4788-413: The practice makes the subject matter that the user is interested in easier to read, usually without sacrificing overall accuracy. Software-based maps often allow the user to toggle decluttering between ON, OFF, and AUTO as needed. In AUTO the degree of decluttering is adjusted as the user changes the scale being displayed. Geographic maps use a projection to translate the three-dimensional real surface of

4864-440: The present. Many published maps are associated in one way or another with the work of Christopher Scotese . The maps are useful since it is usually quite difficult to describe the location and orientation of geographical features using words alone. Map A map is a symbolic depiction of interrelationships, commonly spatial, between things within a space . A map may be annotated with text and graphics. Like any graphic,

4940-413: The relative gradient of a parameter and estimate that parameter at specific places. Contour lines may be either traced on a visible three-dimensional model of the surface , as when a photogrammetrist viewing a stereo-model plots elevation contours, or interpolated from the estimated surface elevations , as when a computer program threads contours through a network of observation points of area centroids. In

5016-407: The same over a single map. When calculated as a ratio against the map scale, a sense of the hilliness of the terrain can be derived. There are several rules to note when interpreting terrain contour lines: Of course, to determine differences in elevation between two points, the contour interval, or distance in altitude between two adjacent contour lines, must be known, and this is normally stated in

5092-571: The same point. In-car global navigation satellite systems are computerized maps with route planning and advice facilities that monitor the user's position with the help of satellites. From the computer scientist's point of view, zooming in entails one or more of: For example: The maps that reflect the territorial distribution of climatic conditions based on the results of long-term observations are called climatic maps . These maps can be compiled both for individual climatic features (temperature, precipitation, humidity) and for combinations of them at

5168-454: The scale statement is nominal it is usually accurate enough for most purposes unless the map covers a large fraction of the Earth. At the scope of a world map, scale as a single number is practically meaningless throughout most of the map. Instead, it usually refers to the scale along the equator. Some maps, called cartograms , have the scale deliberately distorted to reflect information other than land area or distance. For example, this map (at

5244-402: The superimposition of spatially located variables onto existing geographic maps. Having local information such as rainfall level, distribution of wildlife, or demographic data integrated within the map allows more efficient analysis and better decision making. In the pre-electronic age such superimposition of data led Dr. John Snow to identify the location of an outbreak of cholera . Today, it

5320-440: The technique were invented independently, cartographers began to recognize a common theme, and debated what to call these "lines of equal value" generally. The word isogram (from Ancient Greek ἴσος (isos)  'equal' and γράμμα (gramma)  'writing, drawing') was proposed by Francis Galton in 1889 for lines indicating equality of some physical condition or quantity, though isogram can also refer to

5396-484: The world. The earliest surviving maps include cave paintings and etchings on tusk and stone. Later came extensive maps produced in ancient Babylon , Greece and Rome , China , and India . In their simplest forms, maps are two-dimensional constructs. Since the Classical Greek period , however, maps also have been projected onto globes . The Mercator Projection , developed by Flemish geographer Gerardus Mercator ,

5472-424: The year as a whole, sometimes to the four seasons, to the growing period, and so forth. On maps compiled from the observations of ground meteorological stations, atmospheric pressure is converted to sea level. Air temperature maps are compiled both from the actual values observed on the surface of the Earth and from values converted to sea level. The pressure field in the free atmosphere is represented either by maps of

5548-410: The zonal and meridional components of wind are frequently compiled for the free atmosphere. Atmospheric pressure and wind are usually combined on climatic maps. Wind roses, curves showing the distribution of other meteorological elements, diagrams of the annual course of elements at individual stations, and the like are also plotted on climatic maps. Maps of climatic regionalization, that is, division of

5624-400: Was made by Francisco Vela in 1905 and still exists. This map (horizontal scale 1:10,000; vertical scale 1:2,000) measures 1,800 m , and was created to educate children in the scape of their country. Some countries required that all published maps represent their national claims regarding border disputes . For example: Contour line In cartography , a contour line (often just called

5700-594: Was put in place to surround it with a sea of water and at the General's request some of the main rivers were even arranged to flow from headwaters pumped into the mountains. The map was finished in 1979, but had to be restored between 2013 and 2017. The Challenger Relief Map of British Columbia is a hand-built topographic map of the province, 80 feet by 76 feet. Built by George Challenger and his family from 1947 to 1954, it features all of B.C.'s mountains, lakes, rivers and valleys in exact-scaled topographical detail. Residing in

5776-420: Was widely used as the standard for two-dimensional world maps until the late 20th century, when more accurate projections were more widely used. Mercator also was the first to use and popularize the concept of the atlas : a collection of maps. Cartography or map-making is the study and practice of crafting representations of the Earth upon a flat surface (see History of cartography ), and one who makes maps

#456543