Evolution of Maps

 Maps - Its History & Development towards Geology

    Now you have some basic understanding about what geology is & how it got the applied science status. while reading the previous blog you may have a question what is a map? how geologist uses maps to present data and in what way map helps geology to get the applied science status. So today we will explore where the concept of maps was stated, how it evolves with time, and how it got its usage in geology and made a drastic change in its development. So, hey folks, welcome to my blogpost were i will share some of my understanding in geology. 

The Historical record:

   The oldest record is from the ancient tressure land Babylon, were George S Clason found the five laws of Gold (from the book "The Richest Man in Babylon" 1926) our map record history begins.  Around 600 BC Babylonian were making maps on clay tablets. see the image below. where you can see the center of the map to the Babilon itself. The map depicts the physiographic features like islands and mountains, rout for different localities and manmade features. 

600 BC, Babilon clay tablet from collection of the British Museum 

Ptolemyan age:

    Following the Babylonians, Greeks and Romans put more effort towards the development of maps.  One among them is the Claudius Ptolmaeus, was an astronomer lived around 150 AD bring some remarkable development in the map making. some of them were, 

• 

  version of Ptolemy’s world map produced in 1482

  he was the first to introduce the concept latitude and longitude line on maps.
• he imposes mathematical rule to the maps by doing so he developed the concept of scale in maps.
• he published the, Geographia, where he published various parts of the world in systematic way.

his work continued to be grater important for some religious scholars.

Middle age:

Middle age map produced 1154 AD

       In the middle age one of the interesting developments was keeping the Jerusalem in the centre of a ‘world’ map and the Asia at the top of the map, partially for the religious reason and partially for the artistic appeal. One of the greatest works at the time was the work done by the Arabic scholar was an Atlas of map under the impressive title 'The Amusement of him who desires to traverse the Earth’.

Mappa Mundi:

        The map of Mappa Mundi, were the medieval European maps that contains religious, mythological and classical features on the map. the term Mappa means cloth and Mundi means World. These maps were made as a spiritual reference of the ancient world. this Map possess artistic and cultural significance. 

Portolan Charts

Portolan Charts (13th to 16th century)

These are the navigation charts used by European sailors for navigation. these maps were highly accurate, depicts coastlines, harbours, ports and islands. these maps don't have latitude and longitude instead they depend on compass direction. This is the first time where physiographic features were given importance and accurately plotted in the map.

End of 17th century (Layering)

    Layering is a method used to represent the physiographic features, especially the elevation data, in a more detailed way. In this method more importance was given to explain all sort of physiographic features, were a three-dimensional thing (hill, valley, etc) were conveniently projected in a two-dimensional paper with a clarity of elevation. different shades of colours were used to represent the third dimension here. 

              This was more convenient method, as you can enter more data like country/ place name, it also gives you a elevation in sort of range in 1000 feet. but this range of 1000 ft hight depiction is not sufficent for finding slope of the grpond. creating a best root map or flood zoning. 

Timeline of Maps

Contouring:

The concept of contour lines—lines that join points of equal value (such as elevation)—emerged gradually over centuries. The earliest known use was in 1584 by Pieter Bruinsz, who mapped river depths (isobaths) in the Netherlands. By 1746, the technique was applied to land by Domenico Vandelli in Italy. The person most credited with revolutionizing contouring for land elevations is the British mathematician Charles Hutton, who, in 1777, mapped the Scottish mountain Schiehallion using contour lines to calculate its volume for a groundbreaking scientific experiment. This innovation laid the foundation for modern topographic mapping and transformed science’s ability to visualize complex landforms on flat surfaces.

How to Use Contour Lines on a Map

1. Reading the lines:

Each contour line connects points of equal elevation above sea level.

The vertical gap between lines (the “contour interval”) tells you the difference in height between them.

Lines close together mean a steep slope; lines far apart mean a gentle or flat landscape.

Contour lines never cross or split, and they form closed loops (except at the edge of a map).

2. Practical navigation:

By studying the lines, hikers, planners, or anyone can “see” the hills and valleys, even predict how difficult a journey may be.

The contour number reads uphill: the top of the number is higher ground, the bottom lower.

V-shaped “bends” in contour lines show river valleys; the point of the “V” always points upstream.

3. Drawing and using:

Find two known points at different elevations.

Include every point at the same elevation between those levels.

Mark and connect these points as a line—this is your contour!

Where Are Contour Lines Used?

Topographic Maps: Show the shape of the land—mountains, valleys, ridges.

Hydrology: We can also create ground water contour for predict water flow, flood zones, and how rivers travel.

Urban Planning: Engineers use them to design roads and buildings that fit the landscape.

Environmental Science: Mapping pollution, noise levels, soil contamination, and more.

contour line for Geology: 

Contour lines are a geologist’s best friend! Here’s why:

Mapping Rock Layers: Geologists use “structural contour maps” to display underground rock surfaces, faults, and the thickness of geological units (using isopachs—all points with the same rock thickness). This is crucial for oil, gas, and groundwater exploration, and for understanding mineral deposits.

Identifying Folds and Faults: By analyzing the bends and breaks in contour lines, geologists can “read” how rocks have been uplifted, folded, or fractured deep underground.

Landform Analysis: Helps reconstruct the earth’s history by showing how terrain has eroded, filled, or been displaced over time.

Why Do Contour Lines Matter?

Contour lines make invisible landscapes visible. They allow us to flatten the complexity of our three-dimensional world onto maps for navigation, science, and discovery. From planning a mountain trek to searching for hidden oil treasures, contouring shapes the way we see and use our planet.

further reedings

• History of Mapping | Intergovernmental Committee on Surveying and Mapping
• Hall of Maps, Ancient Maps, 6200 B.C. to 600 B.C.
• Cartographic Symbologies, Stanford 
• Geological Digressions: Structural Contour Maps 
• Fiveable: Intro to Geology, Contour Lines