Speleology

Speleology is the scientific study of caves and other karst features.

This field examines the composition, structure, and physical properties of underground spaces. Scientists also study the history and ecology of these environments. They investigate speleogenesis, which is the process of how caves form. They also look at speleomorphology, the study of how caves change over time. While some people use the term to describe the recreational activity of caving, that is a different pursuit. Speleology is a cross-disciplinary science. It combines chemistry, biology, geology, physics, meteorology, and cartography. This allows researchers to build detailed portraits of caves as complex, evolving systems.

Many caves form in landscapes known as karst. This occurs when limestone underneath the ground is eroded away. Most caves are created through a process called dissolution. This is a form of chemical corrosion. In carbonate rocks, dissolution happens through chemical reactions. In rocks like gypsum or rock salt, the process is more physical. In warm climates, silicate rocks can also break down through decomposition.

These various chemical and physical processes work to create large underground cavities over long periods of time.

Inside these caves, you may find beautiful mineral formations called speleothems.

These are geological formations created by mineral deposits that accumulate over time. They most commonly form in calcareous caves through carbonate dissolution reactions. Speleothems take many different shapes depending on their environment. Common types include stalactites, stalagmites, columns, flowstone, drapery, and straws. Because of their gradual growth and chemical makeup, they act as paleoclimatic proxies. This means scientists can use them to learn about the history of past climates.

Microbes also play a massive role in the cave environment. Caves often have stable temperatures and high relative humidity. They also have low rates of evaporation and very little organic material. These conditions are ideal for the growth of microbes. Microbial assemblages include bacteria, fungi, archaea, and other micro-eukaryotes. These communities form the living backbone of cave ecosystems. They help shape cave structures and sustain complex trophic networks. Without these tiny organisms, the energy flow in a cave would be very different.

Cave biology is categorized by how organisms interact with the underground world. There are three main zones: endogean, parahypogean, and hypogean. Endogean zones are parts of caves that connect to surface soils through cracks or roots. Parahypogean zones are threshold regions near cave mouths that still receive some sunlight. The hypogean zone is the "true" cave environment. These areas can be isolated or connected to the surface via underground rivers. In deep hypogean environments, life may rely on chemoautotrophic bacteria. These bacteria use chemical energy from minerals instead of sunlight.

Animals are also classified by their relationship to the cave. Troglobites are specialized cave dwellers that must live in caves to survive. Examples include blindfish, glowworms, and certain flatworms. Troglophiles are cave lovers that can live in caves or on the surface. Bats, spiders, and cave crickets are examples of troglophiles. Trogloxenes are cave guests that only need the cave for part of their life. Hibernating mammals are common examples of this group. Some animals are even accidental trogloxenes, like frogs swept into caves by floods.

These ecosystems are very fragile and can be destroyed by human activities like dam construction or water pollution.

The history of speleology shows how it became a formal science. In the 1680s, John Beaumont wrote detailed descriptions of Mendip caves. The specific term "speleology" was coined by Émile Rivière in 1890. Before the mid-nineteenth century, cave studies were just parts of geography or geology. Édouard-Alfred Martel is known as the father of modern speleology. He introduced the concept of speleology as a distinct area of study. In 1895, he founded the Société de Spéléologie in France. This was the first organization in the world devoted to cave science. Later, the International Union of Speleology was founded in 1965.