Geology: Examining the Planet’s Physical Processes

Defining Geology

Geology - from the Greek geo (Earth) and logia (study) (1) has a long and prestigious history in unlocking many of the secrets of the Earth. We define geology as the study of the Earth, the materials and processes, structure, and even the physics and chemistry that underlie them. It also includes within several of its subdisciplines, the study of material that was once organic but has mineralized. Examples include paleontology and paleobotany (see below). Another area is the examination of change of the physical structures and processes over time.

The more work that geologists can produce on the history, processes, physics and chemistry of our planet, the more we can plan for cataclysmic events such as volcanoes and earthquakes and shifting in plate tectonics that can cause landslides, flooding and avalanches, but also past shifts to understanding profile changes on timescales of thousands or millions of years (2). Also, the more information we have, the better we can understand all geosciences (all sciences concerned with our planet). Nor is geology limited our home planet. Some geologists work with astronomers and astrophysicists to understand the geology of terrestrial bodies such as our Moon and our near rocky planetary neighbors - Mercury, Venus, Mars, asteroids, comets and since 2016, the planetoid Pluto.

Geology also has industrial applications. It is vital to prospecting for and mining of fossil fuels such as natural gas, coal, and crude oil that we convert to fuel our homes, public transportation, and personal vehicles. They examine areas for mining gems and metals too, and groundwater sources. Also, they examine land for new building projects - avoiding tectonic plate areas at high risk of such activity.

Methods in Geology

Modern geology uses a wide range of traditional and technological methods, making it even more accurate and able to produce more data, faster and more accurately than ever before.

Stratigraphy: Used in a wide variety of Earth Sciences / Geosciences, stratigraphy is the study of the layers that make up a geological topography. Each sequence in a layer generally came after the one beneath it. A stratigraphic layer does not represent a period of time, merely a place in a sequence. It can be set down over anything from a few decades (in the case of an archaeological layer) (3) to hundreds of thousands or even millions of years (in the case of geological layers such as the Grand Canyon) (4).

Remote sensing and satellite imagery: Another tool used in many Earth Sciences and not just geology, it's the use of technology to define and locate features and to map locations over a broad area (5). They collect data, sometimes through images, sometimes through heat signatures, resistance signatures (for material density - suggestive of metal ore deposits)

Geophysics: Looking beneath the surface of the Earth without physical investigation, geophysical survey is similar to remote sensing, but it works on a much smaller scale. Used for locating small pockets, the technology is ground-based and examines areas of no more than an acre or two.

Geographic Information Systems: Also known as GIS, this applied science of using information technology with any geographical data allows for visual representation such as digital maps and statistical analyses using database information taken over small or large areas. GIS has many uses in geology from mapping rock surfaces, soils, plotting global tectonic plates and problem areas for volcanoes and earthquakes amongst others.

Geological modelling: Using such tools as information taken from geodesy (see below), remote sensing, geophysical survey, GIS, geologists in most subdisciplines are able to build up digital profiles of a small or large geological area for most applications. It integrates many areas of geology and subdisciplines to create an integrative information source.

History of Geology

In Antiquity

Most thoughts concerning geology focused on the age of the Earth. While humans had mined mineral resources for thousands of years, geology did not expand beyond this small-scale exploitation (6, p1). The great early civilizations of Mesopotamia, Phoenicia, Greece, Rome and others accepted that their creation myths were true but did not attempt to consider the age of the Earth. When the Earth formed and when life began is very much a modern phenomenon, beginning in the 17th century. But that's not to say that the ancient civilizations did not care for anything that concerns modern geology.

We look to Greece for the earliest musings on geology. Unsurprisingly, it is one of the classical world's greatest thinkers in Aristotle although he was not the first. Observing landscapes, he commented on the variation of change and formulated the first idea of geological change - that these changes happen over long-term and generally will not be observed in a single lifetime. He was only half right. In most cases, such changes are slow, hence the term “geological time” but sometimes, a landscape can change in a matter of hours - landslide, storms, earthquakes and volcanoes. Aristotle also believed these sudden phenomena were caused by “violent winds” escaping from the Earth (6, p1).

Xenophanes discovered the first fossils, effectively beginning paleontology, some 100 years before Aristotle who also commented on the discovery of fish fossils on the tops of hills and mountains. The third Greek proto-geologist was Eratosthenes who (rather accurately) predicted the circumference of the Earth. Theophrastus wrote extensively about the nature and profile of rocks (7), discussing their hardness and uses - particularly marble that the Greeks used extensively in their building works. This is the beginning of rock morphology. In Rome, Pliny continued the work of Theophrastus. Together, their work would inform early geology until the early Renaissance.

The Medieval Period

Little advance was made beyond these key figures, though the rise and fall of the Roman Republic and later Empire, and through early medieval period aside from those already discussed. Only at the birth of the Renaissance did humanity begin to contemplate his place in creation, at least in Europe where scholars merely maintained the works of earlier writers. The Middle East and the Far East are a different story. It is believed that the compass was invented in China in the 3rd century BC (8) and spread throughout the Middle East, allowing greater travel across bodies of water. The compass and plotting courses meant shipping would (eventually) no longer be limited to traveling in the shallows of water bodies. At the time, it was likely used to plot land journeys. Also from the Arab World, Abu al-Rayhan al-Biruni is considered one of the earliest true geologists. Like Aristotle several centuries before, he examined topography and hypothesized about how it had changed over long-term. In this case, his examination of the Indian Subcontinent.

Most of the rest of this period was concerned with mineralogy classification and advances in mining. Right across the developed world, larger monuments, buildings and settlements were requiring building materials on the industrial scale. The function would signify the limit of geology until the earliest years of the scientific revolution known as The Enlightenment.

The Renaissance and Enlightenment Revolution

Medieval Europe was still a time of little in the way of advances in geology, even the earliest years of the Renaissance were problematic. Leonardo Da Vinci and Conrad Gesner (6, p2) wrote about fossils but like later works by the likes of Mary Anning and the first paleontologists, these were little more than mere musings on the large-scale processes similar to those that had been published since classical Greece. But Nicholas Steno changed all that. Writing in the late 17th century, he commented extensively on sedimentary layers, demonstrating some of the concepts we now use in the method of stratigraphy (classifying and sequencing layers) (9). From there, geology snowballed. Thinkers in Europe and the Middle East continued to expand the wealth of knowledge available. At last, there began the concept of rock ages based on much longer timescales than had previously been understood (6, p2).

Giovanni Arduino in Italy ordered rocks from primitive to tertiary, and volcanic. Johann Lehmann in Germany classified mountains as old enough to have formed when the world was created, those that formed due to later sediments, and those formed by volcanic activity. The third was Peter Pallas, a Russian, theorized that there had been “uplift” from mountains with signs of previous water coverage. He did not explain this as we would today in terms of the tectonic shift though. At about the same time, George Fuchsel published the world's first book of geological cartography.

Geology as a recognized scientific discipline is now widely regarded as developing between the late 18th and 19th centuries. This was the critical timeframe in which Charles Lyell published “Principles of Geology” (10), Abraham Werner began a formal classification for rocks, James Hutton presented a theory of the formation of the Earth, William Smith enhanced stratigraphy further (6, p3), and Georges Cuvier formulated the first ideas of periodic extinction. It was also during this time that geology began building academic relationships with chemistry and physics. It was only a matter of time before the biblical narrative of creation - and indeed the age of the Earth was called into question. It's also the age of the discovery of fossils, particularly dinosaurs.

The Industrial Revolution

Much of the development of geology through the 19th century is a byproduct of the Industrial Revolution. All over the developed world, governments were granted licenses to mine coal and oil. Geology became as much an application of industry as it was of academic research (11). Mining and canal building permitted researchers to go underground and examine rock formations hundreds of feet deep in ways that were rarely possible before. This was a symbiotic relationship. As geologists developed their knowledge, they were able to assist prospectors in the better understanding and acquisition of these mineral resources. A geological profile of the great continents began to form, and it became clear that the Earth was much older than the biblical accounts suggested. By the time of Charles Darwin, all of science was moving together in suggesting a planet billions of years old and the evidence was stacking up. In 1654, James Ussher calculated (by biblical chronology) that the Earth was created in 4004BC, but this thinking lasted mere decades before the likes of Hutton would challenge it. By the late 19th century and the age of Darwin, geologists had pushed the age of the Earth towards the 100 million mark with some stating a range of 20-100 million (12). This is still way short of the actual number (in the region of 4.5bn) but new developments in physics centering on isotope decay finally began to push that number back even further.

The Early 20th Century

The age of the Earth was the major debate of the early part of the 20th century. Most scientists, stuck with the models of Newtonian Physics, calculated how long it would take for the Earth to cool to current temperatures. They knew little to nothing of the more chaotic aspects that could throw this number out and drive theory towards a more accurate number. Armed with the new knowledge of radioactive decay from the late 19th century, scientists were able to push the date back further still in 1913 when Arthur Holmes published The Age of the Earth. Despite the title, he did not settle on a date - the book examined the dates of rocks and calculated dates of rock features only from there (13). The discovery of radioactive isotopes would present him with a conundrum that would occupy the next few decades, earning Holmes the title of “Father of Geochronology”. By 1946, he had revised upwards to just over 4.5bn and that number has stuck since.

1912 was the year of the first proposal of continental drift, adding a new dimension to geological time and the age of the Earth. It was the brainchild of Alfred Wegener. He presented the idea that the continents once fit together. Starting out as the supercontinent “Pangaea”, they eventually broke up and drifted to where they are now and will continue to do so. Continental Drift (14) is just one theory of how our planet's continents came to be the way they are. His theory was flawed in several ways; he imagined the continents as rafts cutting through ice and did not consider plate tectonics which is slightly related but leads to earthquakes, volcanoes and the formation of hills and mountains too.

Geology from 1950 to the Modern Day

By 1960, Continental Drift was the generally accepted theory and with Plate Tectonics accepted at a symposium in 1965, finally defined the formation of the Earth and gave a great framework for understanding most mechanisms of our planet. The invention of monitoring equipment made predicting earthquakes and volcanoes much easier. But as we were finally piecing together the final puzzles of the Earth's formation, a new challenge beckoned. The 1960s was the beginning of the Space Race. Finally, researchers had new worlds to examine and new puzzles to unravel creating a link with astronomy and astrophysics. Today, geologists are often employed in examining data collected from planets and other large and medium-sized bodies from our Solar System. Recent information from Venus (15, p137-148), Mars (15, p127-136), Mercury and very recently - Pluto (16) - is creating new areas of study.

Geology on Earth began another process of realignment in the latter part of the 20th century where it remains today. It is part of the Earth Sciences or Geosciences, integrating all environmental sciences together for shared data and information to understand how geological events impact the wider environment and vice versa. It created new paradigms and accepted evidence from geography - understanding how ground geology can affect soils, rock layering and profiles of the ocean, and how rock acidity impacts the flora and fauna that inhabit the area. There are now many subdisciplines that reflect all of these new links.

The Subdisciplines of Geology

Economic Geology

This covers all area of geology concerned with material resources of economic value. That means all research, mining, engineering, planning, logistics and other business-related areas for petrochemical, coal and natural gas, prospecting, and mineral, gem and ore mining amongst others (17). It uses applied science and engineering principles as well as theoretical modelling, to examine and predict where new pockets may be. It is through those who work in economic geology and the data they produce around which the debate about peak oil focuses. It is getting increasingly difficult to locate new pockets and access them even with newer technologies. Other areas of geology may take an interest in their data, but often economic geology is more of interest to business and government, especially for those resources close to depletion.

Engineering Geology

Combining another vital area of STEM (engineering) with the theory and applied science of geology, this concerns the alteration of surface and bedrock to improve our built environment (18). All our building works today regardless of size or function - be it commerce, industry, residential, require the skills of engineers and an examination of geology. Skyscrapers in New York are only as tall as they are due to the underlying granite bedrock. It's not possible to build such tall buildings at some other places in the US due to softer rocks and sediments. Increasingly, this area is becoming important for underground engineering projects such as those surrounding hydrogeology and geothermal power sources.

Environmental Geology

Whereas hydrogeology (see below) concerns the interactions of water with geology, environmental geology examines all the Earth's processes and how they impact or are impacted by geology. This is an applied science that also looks to solve environmental issues, usually caused by human action but also natural disasters too, using the principles, methods and tools of geology. It's related to engineering geology but its aims and results are quite different.

Geochemistry

Linking geology with the hard science of chemistry, this area studies the distribution, profiles and origins of chemical elements contained within rocks (19). One of the main questions geochemists attempt to answer is to measure how abundant certain chemicals are in nature and within rock formations, why variations between similar rock types exist, and how they came to form (sedimentary, fossils, volcanic and so on). This information is vital to understanding how and why rock layers form which can fill in pieces of the puzzle of the origins of the Earth.

Geodesy

Traditionally, geodesists used cartography and land markers to plot points and make measurements. But today they are able to produce more accurate readings using the technological tools discussed above such as GIS, aerial survey and GPS, and remote sensing. Geodesy is the science of measurement. That means it employs mathematics too. Geodesy measures physical aspects of the planet such as shape, size, and orientation, but it's also concerned with the less visible aspects of geology - namely the gravity field. Geodesists measure and monitor changes over time. This is the science of land boundaries and national borders (20), of identifying and categorizing topography, of transport and planning infrastructure, sea lanes, and even for military operations planning. The science produces all kinds of maps but is best known for one type - the geoid. This follows global mean sea level for accurate readings for a variety of functions.

Geophysics

Similar to geodesy in that it is about measurements of electrical and magnetic impulses, geophysics differs in that it is the examination of physical properties of landscapes and the space around it (21). It uses geographical markers and boundaries to explore relationships for such issues as mapping. This is more concerned with the physical measurable aspects of topography and of planetary processes. Today, geophysics applies electronic tools such as aerial and ground survey, ground penetrating radar and resistance to discover bedrock, define topography and, in the case of palaeontology and archaeology, discover buried remains by highlighting data anomalies.

Geomorphology

On a similar note, geomorphology is the study of land topography and character, its nature and history of change due to natural erosion and buildup, as well as cataclysmic and sudden change. This means solving such puzzles as landscape evolution by looking at evidence such as seismic activity, air and water erosion, climate and weather, limnology boundaries, and even the results of human actions and how they affect landscapes (22). However, they might also look at evidence from other disciplines such as palaeontology, archaeology and paleobotany. If evidence exists that the land was once under water, or a desert that was once tropical and humid, it will apply that evidence and look for answers. The land is always changing, and it is the remit of geomorphology to discover and explain those changes.

Historical Geology

Most other areas of geology come under physical geology, but historical geology is slightly different. As the name suggests, it examines past landscapes. Sometimes known as paleogeology, experts examine and reconstruct past geological landscapes (23). This area is one of only a handful that applies stratigraphy as an evidence type and is one of only a small number that examines animal and plant fossils as a matter of course to determine how a landscape may have once looked. Geological timescales are broad which means significant changes over thousands and even millions of years. Historical geology can overlap in interests and in research projects with archaeology and paleontology. All have benefited from the development of absolute dating methods too (radiometric dating).

Hydrogeology

Water and its movements are just one tool by which ground geology has been shaped over billions of years. This subsection of geology examines groundwater, its distribution and movements through rock formations and in soil (including water tables and floodplains) all the way down to the Earth's crust and its interactions. This can also involve human engineering of groundwater to create water supplies, harness springs, drainage and irrigation. They will also be interested in pollution and contamination risk, conservation of limited supplies (such as in arid areas and ensuring water security) and continued quality for human use and consumption. Hydrogeologists look to harness and manipulate water supplies for people and the environment.

Marine Geology

Sometimes known as “ocean geology”, this concerns the movements of bedrock and other physical processes of the oceans, plate tectonics, continental drift and so on, but also areas affected by the oceans. That includes coastal floodplains, continental boundaries, beaches, river estuaries and lakes that empty into oceans (24). The unique geology of the oceans makes it a special case and as water accounts for around of the Earth's surface, that requires specialism for the unique properties of ocean geology. Marine geology can encompass natural resource extraction such as fossil fuels, the impacts of earthquakes and tidal waves and tsunamis, hurricanes and other weather phenomena.

Mineralogy

Minerals are a unique area of geology defined as having a unique and homogeneous chemical composition and a “highly-ordered” structure (25) repeated throughout a geological formation. Their unique properties are of special use to humanity and have been since antiquity. Typically, minerals include flint and quartz, clay, rock salt, calcite and pyrite. These were fundamental to food preservation and early industry (clay for pottery, quartz and flint for tools) and mining is one of the oldest industries.

Gemology

This niche area of mineralogy concerns everything that mineralogy entails including the economics, location and scientific study, but limited to precious metals and gemstones (26). This means gold and silver, rubies, topaz, diamond and so on. It's necessary to determine diamond from zircon, sapphire from kyanite, and tsavorite from emerald. Many of these look the same to the naked eye but have different properties and chemical structures.

Mining Geology

This, as it sounds, is the geology of mining. This includes prospecting, siting, environmental impact, engineering, economics and other areas of mining for resources. It's an applied science, utilizing information, methods and practices from a variety of areas such as mineralogy, economic geology, and geological engineering.

Paleontology

This is the study of the fossilized remains of dead living material, typically extinct species. It's considered a subdiscipline of geology because these soft and bone remains have mineralized (turned to stone) and are preserved inside rocks - typically fossilized sediments such as dried up sea beds. Paleontologists are multidisciplinary, requiring an understanding of zoology, anatomy, ecology and many other areas (27). Today, we limit paleontology to fossilized animals with many of its own subdivisions applying to other areas of the paleoenvironment. A subdiscipline of this studies plants.

Paleobotany

Everything expressed above as applying to paleontology applies to paleobotany. The only difference being that instead of studying the remains of dead, fossilized animals, they study plants, plant remains, pollen, phytoliths and anything else from the plant kingdom.

Petroleum Geology

Some plant and animal remains do not mineralize in the way that paleontological or paleobotanical sediments form, they undergo unique chemical processes that turn them to coal, oil, and natural gas. These have energy properties that we use as fossil fuels in an internal combustion engine. Petroleum geologists study the chemical processes that form fossil fuels, but also look for occurrences, conditions and movement, and use unique methods and tools to locate them. It overlaps in some areas with economic geology, geological engineering, sometimes with paleontology and paleobotany, but also with a mindset of looking for sources with economic value (28).

Petrology

This is an applied area of geology that studies how rocks form (29). Each rock type has a specific chemical signature requiring certain processes to form. There are three basic rock types that this area covers with the first two tended to come together because they are heavily chemistry based.

Igneous Petrology: covers igneous rocks which are the result of volcanic processes, the cooling of magma or lava - basalt, granite, for example

Metamorphic Petrology: covers metamorphic rocks which began as sedimentary or igneous but have undergone physical or chemical changes to turn them into something else. This includes slate and marble

Sedimentary Petrology: This stands apart from the other two as its less about chemical processes and more concerned with geological timeframes. Therefore, it's often taught in conjunction with stratigraphy. Sandstone and limestone are sedimentary rocks

More recently, a new subdiscipline to petrology has been added. This is experimental petrology which is the study of synthetic materials with applied chemical processes through which researchers are able to explore rocks in the sub-surfaces of the Earth such as the mantle

Photogeology

A relatively new development in geology, this is the application of photographic technologies in all geological investigations (30). Therefore, it is as much a method as it is a subdiscipline but considered a subdiscipline because of the range of specialist niche skills required in such a study. Photogeology includes methods such as aerial survey, satellite imagery (standard as well as specialist photography such as heat signatures), and use this data to interpret geological actions and interactions. They may use other technologies in such studies such as Geographical Information Systems (GIS). Such methods used in photogeology are not designed to replace traditional ground survey or site visits but complement them for a wider aerial view.

Planetary Geology

The exploration of our nearest rocky planetary neighbors as Mercury, Venus, Mars, and of course the Moon, has presented new data in our understanding of geological formations and processes. Planetary geology looks at geology on a planet-wide scale but not limited to the one on which we live (31). This extra wealth of data can help us understand how planets, moons and other geological bodies may form in the universe, how they become moons or planets and broaden our understanding of plate tectonics, amongst other things. Releasing this data should help with the planned colonization of other planets in our solar system and beyond.

Plate tectonics vary elsewhere in the Solar System. Signs have been found on Mars (34) - Vallis Marineris, and the Tharsis Bulge and Olympus Mons (the largest volcano in the Solar System). Mars is no longer geologically active; on Venus, there are also signs of geological activity (35) but not plate tectonics as we understand them on Earth.

Quaternary Geology

Geology, by definition, covers the geological and planetary processes over the entire history of the planet Earth. Quaternary Geology places a time limit on this by looking only at the last 2.6m years (32). Why is this necessary? Because the regular phases of glacial advance and retreat in this period and the sheer number of ice ages have come to shape our modern planet. They examine such geological features, forms and processes as glaciation and landscape change, landscape evolution such as hills and mountains, surface deposits, climate change cycles and stratigraphy.

Sedimentology

Geologists who work in this area examine sand, silt, marble, and clay deposits and how they are deposited (33) including movements. This information is used to examine much older deposits to formulate how they may have formed and the processes that shape sedimentary rocks. Most rock formations on Earth today are sedimentary, up to 75% of the total mass. What is particularly useful about sedimentary rock is that they create the perfect conditions for the preservation of fossils. They also contain much of the planet's groundwater aquifers. How much and how we can access this water depends on studies into sedimentology.

Seismology

Earthquakes are formed when ripples of energy spread out along a rock feature and indicate the likelihood of earthquakes. Movements are natural and most are harmless (indicated by a low number on the Richter Scale) but some are cataclysmic events that can kill and injure and cause massive destruction. However, they are a natural part of the Earth's processes, shaping the land over the billions of years of the planet's life (36). Seismologists record and monitor energy signatures from the different types of waves.

Speleology

Whereas geology is the study of rock formations and how they form and are created, speleology effectively studies how they erode in certain ways to create potholes and caves. They have a unique ecology and geological profile of their own that requires a specialist area of study; cave creating involves the removal of geology instead of its deposition. The term used to refer to cave explorers but these people are now known as “potholers” while the scientific research of caves and cave systems known as speleology (37). They use applied science methods from chemistry, biology, physics, geography and even archaeology and paleontology.

Structural Geology

This area of geology examines the 3D distribution of rock profiles units and examining their past profiles (38). It is the taking of measurements of what rock formations look like today to determine what it may have looked like in the past and what may have altered it. Stresses and pressures can warp rocks and it is as much about identifying these stresses and pressures (volcanic activity, cave collapse, sediment and flooding, plate tectonics creating hills and mountains) as it is about recognizing its results. Structural geology then is about geological evolution and change.

Volcanology

This area of geology is the branch covering the geological phenomena known as volcanoes, but also their actions such as lava and magma. Anything related to volcanoes - whether extinct, dormant or active, is covered by volcanology. That often means using the same tools and technologies as seismologists, looking for similar signatures. They examine the formation of volcanoes and the prediction of new eruptions of existing volcanoes. They will visit sites and collect geological material for analysis to try to understand not just volcanoes, but to piece together some of the complex pieces of the puzzle of planetary history.

Potential Future Approaches and Challenges for Geology

Some claim that geology has nothing left to discover. This is unlikely although the big discoveries are behind it, the future is hardly one where the science wanes. The following is a list of potential few challenges and avenues for the science to explore and grow.

Geologists Have Nothing Left to Uncover on Earth

One of the biggest questions for geology to answer is, “what next?” It is the perception of researchers in most geosciences, and especially in geology, that all the big questions have already been answered (39). While this may be true from the perspective of planet Earth, astronomers, astrophysicists and others concerned with other planets and the wider cosmos might disagree as we branch out into our Solar System. The next 25 years and beyond may be one in which geology undergoes yet more fundamental shifts and moves towards areas which would have been inconceivable before the beginning of the Space Race.

Geology may also become more of an applied science and become absorbed into environmental conservation. It is already a strong geoscience and as geologists deal (in some cases) with finite resources such as minerals and fossil fuels, their remit may become research-intensive in their preservation and better management of resources. This will not be universal as some minerals have the potential to last thousands of years.

Employment in a Post-Oil World

The revolution in green technology is necessary and will drive employment but for some who presently work in geology, it will mean upskilling. It will mean the need for a career change with many lost jobs presently employed in the petrochemical industry. Jobs will be lost in oil and gas prospecting, but areas such as engineering are expected to ride the storm and maybe even increase job roles; however, the old industries will slowly disappear. Renewable energy will certainly need continued investment and the expert research and applied science of geology through tidal power, hydroelectricity, sites for wind turbines and even for new developments in emerging technologies. BLS predicts a job growth of 14% between 2016 and 2026.

Geothermal Energy

One of the potential areas for geologists and geological engineers to move is towards geothermal energy production. This is boring through the ground to reach the hot rocks inside the crust to draw heat and energy up to the surface. It is a renewable energy that will require research and investment from geology (40, p50-59). Hot springs and geysers are sources of natural volcanic energy but in theory and with the right investment in the right places, virtually anywhere on Earth should be able to harness this energy. It's one of the great potential future challenges for geology and likely to provide new opportunities for investment and employment for the geologists of the next few decades.

So-Called “Clean Coal” - Carbon Capture and Storage

This is a matter of some controversy with geologists at the center of the storm. Proposed during Kyoto, the idea of capturing carbon during the burning of coal and storing it sounds like a good idea in principle, but this is a misnomer. It is not going to eliminate the carbon produced by burning coal (40, p28-39). There are already billions of tons of carbon stored underground in natural pockets, geological engineers seek to reproduce this on an industrial scale. However, most environmentalists and green tech experts oppose it on the grounds of there being much cheaper, safer and alternative renewable energies that we may harvest. Geologists may be at the forefront of developing the technology as they are for developing renewables.

Shale Gas “Fracking”

Another unpopular energy acquisition method is shale gas hydraulic fracturing (41). Harnessing underground geology, it involves drilling down into rock for 1-2 miles at an angle. This is then reinforced with steel or concrete and the drill then diverts to drill sideways for around 1 mile. High-pressure fluid is then pumped into the well, powerful enough to fracture the rocks and release the fossil fuels contained within it. This has met with controversy and opposition across the developed world. The technology may not be available until around 2025 and it should provide employment opportunities for more geologists. However, opposition to the technology and specific concerns about pollution mean this is one of the flashpoints between governments who argue it is a simple, easy and cheap method of energy acquisition and the public concerned about environmental protection.

Water Conservation and Security

It's widely been recognized that humanity needs to utilize water resources far better than we already do. This will apply especially in marginal landscapes such as dry, arid areas. The droughts and wildfires facing some areas of California over the last decade have certainly shown what can happen when water resources are overstretched. Geologists may be called on to mine for water resources or to create great engineering works such as hydroelectricity and underground reservoirs to store water. We need water for food, for crops, for homes and for industry; water conservation and security could be one of the greatest challenges of this century.

Planetary Colonization

As discussed several times throughout this article, towards the middle and end of this century, geology may experience a great renaissance. Those who say that the biggest discoveries have already been made and the great mysteries already solved will find new outlets for research and applied geology on other worlds. Yet our nearest neighbors remain, in many ways, a mystery despite the limited knowledge we have already acquired, especially about Mars (42). At present, the first manned mission to Mars with colonists is due to launch in the early 2020s. We know a little about the geology of that planet and our other nearest neighbor Venus but being physically present on the planet will aid geologists in understanding Mars from the ground. New areas of research and new data will gradually bring together the picture of how planets form and how they change over time.

Sources

Matthew Mason

MG Mason has a BA in Archaeology and MA in Landscape Archaeology, both from the University of Exeter. A personal interest in environmental science grew alongside his formal studies and eventually formed part of his post-graduate degree where he studied both natural and human changes to the environment of southwest England; his particular interests are in aerial photography. He has experience in GIS (digital mapping) but currently works as a freelance writer as the economic downturn means he has struggled to get relevant work. He presently lives in southwest England.