Most individuals define geography as a field of study that deals with maps, yet this definition is only partially correct. A better definition of geography may be the study of natural and human-constructed phenomena relative to a spatial dimension.
The discipline of geography has a history that stretches over many centuries. Over this period, geography has evolved and developed into an essential form of human scholarship. Examining the historical evolution of geography as a discipline provides some essential insights concerning its character and methodology. These insights are also helpful in gaining a better understanding of the nature of physical geography.
As stated by Dartmounth Library, “the study of the interrelationships between people, place, and environment, and how these vary spatially and temporally across and between locations. Whereas physical geography concentrates on spatial and environmental processes that shape the natural world and tends to draw on the natural and physical sciences for its scientific underpinnings and methods of investigation, human geography concentrates on the spatial organization and processes shaping the lives and activities of people, and their interactions with places and nature. Human geography is more allied with the social sciences and humanities, sharing their philosophical approaches and methods.
History of Geography
Some of the first genuinely geographical studies occurred more than four thousand years ago. The primary purpose of these early investigations was to map features and places observed as explorers traveled to new lands. At this time, Chinese, Egyptian, and Phoenician civilizations were beginning to explore the places and spaces within and outside of their homelands. The earliest evidence of such explorations comes from the archaeological discovery of a Babylonian clay tablet map that dates back to 2300 BC.
The early Greeks were the first civilization to practice a form of geography that was more than just map-making or cartography. Greek philosophers and scientist were also interested in learning about spatial nature of human and physical features found on the Earth. One of the first Greek geographers was Herodotus (circa 484 – 425 BC). Herodotus wrote some volumes that described the human and physical geography of the various regions of the Persian Empire.
The ancient Greeks were also interested in the form, size, and geometry of the Earth. Aristotle (circa 384 – 322 BC) hypothesized and scientifically demonstrated that the Earth had a spherical shape. Evidence for this idea came from observations of lunar eclipses. Lunar eclipses occur when the Earth casts its circular shadow on to the moon’s surface. The first individual to accurately calculate the circumference of the Earth was the Greek geographer Eratosthenes (circa 276 – 194 BC). Eratosthenes calculated the equatorial circumference to be 40,233 kilometers using simple geometric relationships. This first calculation was unusually accurate. Measurements of the Earth using modern satellite technology have computed the circumference to be 40,072 kilometers.
Most of the Greek accomplishments in geography were passed on to the Romans. Roman military commanders and administrators used this information to guide the expansion of their Empire. The Romans also made several notable additions to geographical knowledge. Strabo (circa 64 BC – 20 AD) wrote a 17 volume series called “Geographia.” Strabo claimed to have traveled widely and recorded what he had seen and experienced from a geographical perspective. In his series of books, Strabo describes the cultural geographies of the various societies of people found from Britain to as far east as India and south to Ethiopia and as far north as Iceland. Strabo also suggested a definition of geography that is quite complementary to the way many human geographers define their discipline today. This definition suggests that geography aimed to “describe the known parts of the inhabited world… to write the assessment of the countries of the world [and] to treat the differences between countries.”
During the second century AD, Ptolemy (circa 100 – 178 AD) made some important contributions to geography. Ptolemy’s publication Geographike hyphegesis or “Guide to Geography” compiled and summarize much of the Greek and Roman geographic information accumulated at that time. Some of his other notable contributions include the creation of three different methods for projecting the Earth’s surface on a map, the calculation of coordinate locations for some eight thousand places on the Earth, and development of the concepts of geographical latitude and longitude.
Little academic progress in geography occurred after the Roman period. For the most part, the Middle Ages (5th to 13th centuries AD) were a time of intellectual stagnation. In Europe, the Vikings of Scandinavia were the only group of people carrying out active exploration of new lands. In the Middle East, Arab academics began translating the works of Greek and Roman geographers starting in the 8th century and began exploring southwestern Asia and Africa. Some of the essential intellectuals in Arab geography were Al-Idrisi, Ibn Battutah, and Ibn Khaldun. Al-Idrisi is best known for his skill at making maps and for his work of descriptive geography Kitab nuzhat al-mushtaq fi ikhtiraq al-afaq or “The Pleasure Excursion of One Who Is Eager to Traverse the Regions of the World.” Ibn Battutah and Ibn Khaldun are well known for writing about their extensive travels of North Africa and the Middle East.
During the Renaissance (1400 to 1600 AD) numerous journeys of geographical exploration were commissioned by a variety of nation-states in Europe. Most of these voyages were financed because of the potential commercial returns from resource exploitation. The voyages also provided an opportunity for scientific investigation and discovery. These voyages also added many significant contributions to geographic knowledge. Important explorers of this period include Christopher Columbus, Vasco da Gama, Ferdinand Magellan, Jacques Cartier, Sir Martin Frobisher, Sir Francis Drake, John and Sebastian Cabot, and John Davis. Also during the Renaissance, Martin Behaim created a spherical globe depicting the Earth in its true three-dimensional form in 1492. Behaim’s invention was a significant advance over two-dimensional maps because it created a more realistic depiction of the Earth’s shape and surface configuration.
In the 17th century, Bernhardus Varenius (1622-1650) published an important geographic reference titled Geographia generalis (General Geography: 1650). In this volume, Varenius used direct observations and primary measurements to present some new ideas concerning geographic knowledge. This work continued to be a standard geographic reference for about a 100 years. Varenius also suggested that the discipline of geography could be subdivided into three distinct branches. The first branch examines the form and dimensions of the Earth. The second sub-discipline deals with tides, climatic variations over time and space, and other variables that are influenced by the cyclical movements of the Sun and moon. Together these two branches form the early beginning of what we collectively now call physical geography. The last branch of geography examined distinct regions on the Earth using comparative cultural studies. Today, this area of knowledge is called cultural geography.
During the 18th century, the German philosopher Immanuel Kant (1724-1804) proposed that human knowledge could be organized in three different ways. One way of organizing knowledge was to classify its facts according to the type of objects studied. Accordingly, zoology studies animals, botany examines plants, and geology involves the investigation of rocks. The second way one can study things is according to a temporal dimension. This field of knowledge is, of course, called history. The last method of organizing knowledge involves understanding facts relative to spatial relationships. This field of knowledge is commonly known as geography. Kant also divided geography into some sub-disciplines. He recognized the following six branches: Physical, mathematical, moral, political, commercial, and theological geography.
Geographic knowledge saw strong growth in Europe and the United States in the 1800s. This period also saw the emergence of a number of societies interested in geographic issues. In Germany, Alexander von Humboldt, Carl Ritter, and Fredrich Ratzel made substantial contributions to human and physical geography. Humboldt’s publication Kosmos (1844) examines the geology and physical geography of the Earth. This work is considered by many academics to be a milestone contribution to geographic scholarship. Late in the 19th Century, Ratzel theorized that the distribution and culture of the Earth’s various human populations were strongly influenced by the natural environment. The French geographer Paul Vidal de la Blanche opposed this revolutionary idea. Instead, he suggested that human beings were a dominant force shaping the form of the environment. The idea that humans were modifying the physical environment was also prevalent in the United States. In 1847, George Perkins Marsh gave an address to the Agricultural Society of Rutland County, Vermont. The subject of this speech was that human activity was having a destructive impact on the land, primarily through deforestation and land conversion. This speech also became the foundation for his book Man and Nature or The Earth as Modified by Human Action, first published in 1864. In this publication, Marsh warned of the ecological consequences of the continued development of the American frontier.
During the first 50 years of the 1900s, many academics in the field of geography extended the various ideas presented in the previous century to studies of small regions all over the world. Most of these studies used descriptive field methods to test research questions. Starting around 1950, geographic research experienced a shift in methodology. Geographers began adopting a more scientific approach that relied on quantitative techniques. The quantitative revolution was also associated with a change in the way in which geographers studied the Earth and its phenomena. Researchers now began investigating process rather than a mere description of the event of interest. Today, the quantitative approach is becoming even more prevalent due to advances in computer and software technologies.
In 1964, William Pattison published an article in the Journal of Geography (1964, 63: 211-216) that suggested that modern Geography was now composed of the following four academic traditions:
- Spatial Tradition – the investigation of the phenomena of geography from a strictly spatial perspective.
- Area Studies Tradition – the geographical study of an area on the Earth at either the local, regional, or global scale.
- Human-Land Tradition – the geographical study of human interactions with the environment.
- Earth Science Tradition – the study of natural phenomena from a spatial perspective. This tradition is best described as theoretical physical geography.
Today, the academic traditions described by Pattison are still dominant fields of geographical investigation. However, the frequency and magnitude of human-mediated environmental problems have been on a steady increase since the publication of this notion. These increases are the result of a growing human population and the consequent increase in the consumption of natural resources. As a result, an increasing number of researchers in geography are studying how humans modify the environment. A significant number of these projects also develop strategies to reduce the negative impact of human activities on nature. Some of the dominant themes in these studies include environmental degradation of the hydrosphere, atmosphere, lithosphere, and biosphere; resource use issues; natural hazards; environmental impact assessment; and the effect of urbanization and land-use change on natural environments.
Considering all of the statements presented concerning the history and development of geography, we are now ready to formulate a somewhat coherent definition. This definition suggests that geography, in its purest form, is the field of knowledge that is concerned with how phenomena are spatially organized. Physical geography attempts to determine why natural phenomena have particular spatial patterns and orientation. This online textbook will focus primarily on the Earth Science Tradition. Some of the information that is covered in this textbook also deals with the alterations of the environment because of human interaction. These pieces of information belong in the Human-Land Tradition of geography.
Elements of Geography
Geography is a discipline that integrates a wide variety of subject matter. Almost any area of human knowledge can be examined from a spatial perspective. Physical geography’s primary subdisciplines study the Earth’s atmosphere (meteorology and climatology), animal and plant life (biogeography), physical landscape (geomorphology), soils (pedology), and waters (hydrology). Some of the principal areas of study in human geography include human society and culture (social and cultural geography), behavior (behavioral geography), economics (economic geography), politics (political geography), and urban systems (urban geography).
Holistic synthesis connects knowledge from a variety of academic fields in both human and physical geography. For example, the study of the enhancement of the Earth’s greenhouse effect and the resulting global warming requires a multidisciplinary approach for complete understanding. The fields of climatology and meteorology are required to understand the physical effects of adding additional greenhouse gases to the atmosphere’s radiation balance. The field of economic geography provides information on how various forms of human economic activity contribute to the emission of greenhouse gases through fossil fuel burning and land-use change. Combining the knowledge of both of these academic areas gives us a more comprehensive understanding of why this environmental problem occurs.
The holistic nature of geography is both a strength and a weakness. Geography’s strength comes from its ability to connect functional interrelationships that are not generally noticed in narrowly defined fields of knowledge. The most apparent weakness associated with the geographical approach is related to the fact that holistic understanding is often too simple and misses essential details of cause and effect.
What distinguishes human geography from other related disciplines, such as development, economics, politics, and sociology, are the application of a set of core geographical concepts to the phenomena under investigation, including space, scale, landscape, mobility, and nature. These concepts foreground the notion that the world operates spatially and temporally, and that social relations do not operate independently of place and environment, but are thoroughly grounded in and through them.”
At the heart of the spatial perspective is the question of “where,” but there are a number of different ways to answer this question. Relative location refers to the location of a place relative to other places, and we commonly use relative location when giving directions to people. We might instruct them to turn “by the gas station on the corner,” or say that we live “in the dorm across from the fountain.” Another way to describe a place is by referring to its absolute location. Absolute location references an exact point on Earth and commonly uses specific coordinates like latitude and longitude. Lines of latitude and longitude are imaginary lines that circle the globe and form the geographic coordinate system. Lines of latitude run laterally, parallel to the equator, and measure distances north or south of the equator. Lines of longitude, on the other hand, converge at the poles and measure distances east and west of the prime meridian.
Every place on Earth has a precise location that can be measured with latitude and longitude. The location of the White House in Washington, DC, for example, is located at latitude 38.8977 °N and longitude 77.0365°W. Absolute location might also refer to details like elevation. The Dead Sea, located on the boundary of Jordan and Israel, is the lowest location on land, dipping down to 1,378 feet below sea level.
Historically, most maps were hand-drawn, but with the advent of computer technology came more advanced maps created with the aid of satellite technology. Geographic information science (GIS), sometimes also referred to as geographic information systems, uses computers and satellite imagery to capture, store, manipulate, analyze, manage, and present spatial data. GIS primarily uses layers of information and is often used to make decisions in a wide variety of contexts. An urban planner might use GIS to determine the best location for a new fire station, while a biologist might use GIS to map the migratory paths of birds. We use GIS to get navigation directions from one place to another, layering place names, buildings, and roads.
One difficulty with map-making, even when using advanced technology, is that the Earth is roughly a sphere while maps are generally flat. When converting the spherical Earth to a flat map, some distortion always occurs. A map projection, or a representation of Earth’s surface on a flat plane, always distort at least one of these four properties: area, shape, distance, and direction. Some maps preserve three of these properties, while significantly distorting another, while other maps seek to minimize overall distortion but distort each property somewhat. So, which map projection is best? That depends on the purpose of the map. The Mercator projection, while significantly distorting the size of places near the poles, preserves angles and shapes, making it ideal for navigation.
The Winkel Tripel projection is so-named because its creator, Oswald Winkel, sought to minimize three kinds of distortion: area, direction, and distance. The National Geographic Society has used it since 1998 as the standard projection of world maps.
When representing the Earth on a manageable-sized map, the actual size of the location is reduced. Scale is the ratio between the distance between two locations on a map and the corresponding distance on Earth’s surface. A 1:1000 scale map, for example, would mean that 1 meter on the map equals 1000 meters, or 1 kilometer, on Earth’s surface. Scale can sometimes be a confusing concept for students, so it is important to remember that it refers to a ratio. It does not refer to the size of the map itself, but rather, how zoomed in or out the map is. A 1:1 scale map of your room would be the same size of your room – plenty of room for significant detail, but hard to fit into a glove compartment.
As with map projections, the “best” scale for a map depends on what it is used for. If you are going on a walking tour of a historic town, a 1:5,000 scale map is commonly used. If you are a geography student looking at a map of the entire world, a 1:50,000,000 scale map would be appropriate. “Large” scale and “small” scale refer to the ratio, not to the size of the landmass on the map. 1 divided by 5,000 is 0.0002, which is a larger number than 1 divided by 50,000,000 (which is 0.00000002). Thus, a 1:5,000 scale map is considered “large” scale while 1:50,000,000 is considered “small” scale.
All maps have a purpose, whether it is to guide sailing ships, help students create a more accurate mental map of the world, or tell a story. The map projection, color scheme, scale, and labels are all decisions made by the mapmaker. Some argued that the widespread use of the Mercator projection, which made Africa look smaller relative to North America and Eurasia, led people to minimize the importance of Africa’s political and economic issues. Just as texts can be critiqued for their style, message, and purpose, so too can maps be critiqued for the information and message they present.
The spatial perspective, and answering the question of “where,” encompasses more than just static locations on a map. Often, answering the question of “where” relates to movement across space. Diffusion refers to the spreading of something from one place to another, and might relate to the physical movement of people or the spread of disease, or the diffusion of ideas, technology, or other intangible phenomena. Diffusion occurs for different reasons and at different rates. Just as static features of culture and the physical landscape can be mapped, geographers can also map the spread of various characteristics or ideas to study how they interact and change.
When we describe places, we can discuss their absolute and relative location and their relationship and interaction with other places. As regional geographers, we can dig deeper and explore both the physical and human characteristics that make a particular place unique. Geographers explore a wide variety of spatial phenomena, but the discipline can roughly be divided into two branches: physical geography and human geography. Physical geography focuses on natural features and processes, such as landforms, climate, and water features. Human geography is concerned with human activity, such as culture, language, and religion. However, these branches are not exclusive. You might be a physical geographer who studies hurricanes, but your research includes the human impact from these events. You might be a human geographer who studies food, but your investigations include the ecological impact of agricultural systems. Regional geography takes this holistic approach, exploring both the physical and human characteristics of the world’s regions.
Much of Earth’s physical landscape, from mountains to volcanoes to earthquakes to valleys, has resulted from the movement of tectonic plates. As the theory of plate tectonics describes, these rigid plates are situated on top of a bed of molten, flowing material, much like a cork floating in a pot of boiling water. There are seven major tectonic plates and numerous minor plates.
Where two tectonic plates meet is known as a plate boundary, and boundaries can interact in three different ways. Where two plates slide past one another is called a transform boundary. The San Andreas Fault in California is an example of a transform boundary. A divergent plate boundary is where two plates slide apart from one another. This type of plate movement formed Africa’s Rift Valley.
Convergent plate boundaries occur when two plates slide towards one another. In this case, where two plates have roughly the same density, upward movement can occur, creating mountains. The Himalaya Mountains, for example, were formed from the Indian plate converging with the Eurasian plate. In other cases, subduction occurs, and one plate slides below the other. Here, deep, under-ocean trenches can form. The 2004 Indian Ocean earthquake and tsunami occurred because of a subducting plate boundary off the west coast of Sumatra, Indonesia.
The interaction between tectonic plates and historical patterns of erosion and deposition have generated a variety of landforms across Earth’s surface. Each of the world’s regions has identifiable physical features, such as plains, valleys, mountains, and major water bodies. Topography refers to the study of the shape and features of the surface of the Earth. Areas of high relief have significant changes in elevation on the landscape, such as steep mountains, while areas of low relief are relatively flat.
Another critical feature of Earth’s physical landscape is the climate. Weather refers to the short-term state of the atmosphere. We might refer to the weather as partly sunny or stormy, for example. Climate, on the other hand, refers to long-term weather patterns and is affected by a place’s latitude, terrain, altitude, and nearby water bodies.
Geographers commonly use the Köppen climate classification system to refer to the major climate zones found in the world. Each climate zone in the Köppen climate classification system is assigned a lettered code, referring to the temperature and precipitation patterns found in the particular region. Climate varies widely across Earth. Cherrapunji, India, located in the CWB climate zone, receives over 11,000 mm (400 in) of rain each year. In contrast, the Atacama Desert (BWk), situated along the western coast of South America across Chile, Peru, Bolivia, and Argentina, typically receives only around 1 to 3 mm (0.04 to 0.12 in) of rain each year.
Earth’s climate has gone through significant changes historically, alternating between long periods of warming and cooling. Since the industrial revolution in the 1800s, however, global climate has experienced a warming phase. Ninety-five percent of scientists agree that this global climate change has resulted primarily from human activities, particularly the emission of greenhouse gasses like carbon dioxide. 15 of the 16 warmest years ever recorded have occurred since 2000. Overall, this warming has contributed to rising sea levels as the polar ice caps melt, changing precipitation patterns, and the expansion of deserts. The responses to global climate change, and the impacts from it vary by region.