Chapter 2 The System of The Geography

The Four Spheres
It’s a little deceiving (even overly simplistic) to say that physical geography studies the Earth as our home and looks at the four spheres because each possible area of research encompasses so much.

The atmosphere itself has several layers to study, but the atmosphere as a topic under the lens of physical geography also includes research areas such as the ozone layer, the greenhouse effect, wind, jet streams, and weather.

The hydrosphere encompasses everything having to do with water, from the water cycle to acid rain, groundwater, runoff, currents, tides, and oceans.

The biosphere concerns living things on the planet and why they live where they do, with topics from ecosystems and biomes to food webs and the carbon and nitrogen cycles.

The study of the lithosphere includes geological processes, such as the formation of rocks, plate tectonics, earthquakes, volcanoes, soil, glaciers, and erosion.

Sub-Branches of Physical Geography

Since the Earth and its systems are so complex, there are many sub-branches and even sub-sub-branches of physical geography as a research area, depending on how granularly the categories are divided. They also have overlap between them or with other disciplines, such as geology.

Geographical researchers will never be at a loss of something to study, as they often need to understand multiple areas to inform their own targeted research.

Geomorphology: the study of Earth’s landforms and its surface’s processes—and how these processes change and have changed Earth’s surface—such as erosion, landslides, volcanic activity, earthquakes, and floods.

Hydrology: the study of the water cycle, including water distribution across the planet in lakes, rivers, aquifers, and groundwater; water quality; drought effects; and the probability of flooding in a region. Potamology is the study of rivers.

Glaciology: the study of glaciers and ice sheets, including their formation, cycles, and effect on Earth’s climate.

Biogeography: the study of the distribution of life forms across the planet, relating to their environments; this field of study is related to ecology, but it also looks into the past distribution of life forms as well, as found in the fossil record.

Meteorology: the study of Earth’s weather, such as fronts, precipitation, wind, storms, and the like, as well as forecasting short-term weather based on available data.

Climatology: the study of Earth’s atmosphere and climate, how it has changed over time, and how humans have affected it.

Pedology: the study of soil, including types, formation, and regional distribution over Earth.

Paleogeography: the study of historical geographies, such as the location of the continents over time, through looking at geological evidence, such as the fossil record.

Coastal geography: the study of the coasts, specifically concerning what happens where land and water meet.

Oceanography: the study of the world’s oceans and seas, including aspects such as floor depths, tides, coral reefs, underwater eruptions, and currents. Exploration and mapping is a part of oceanography, as is research into the effects of water pollution.

Quaternary science: the study of the previous 2.6 million years on Earth, such as the most recent ice age and Holocene period, including what it can tell us about the change in Earth’s environment and climate.

Landscape ecology: the study of how ecosystems interact with and affect each other in an area, especially looking at the effects of the uneven distribution of landforms and species in these ecosystems (spatial heterogeneity).

Geomatics: the field that gathers and analyzes geographic data, including the gravitational force of Earth, the motion of the poles and Earth’s crust, and ocean tides (geodesy). In geomatics, researchers use the Geographic Information System (GIS), which is a computerized system for working with map-based data.

Environmental geography: the study of the interactions between people and their environment and the resulting effects, both on the environment and on the people; this field bridges physical geography and human geography.

Astronomical geography or astronography: the study of how the sun and moon affect the Earth as well as our planet’s relationship to other celestial bodies.