The carbon cycle is that part of the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of Earth. Other major biogeochemical cycles include the nitrogen cycle and the water cycle. Carbon is the main component of biological compounds as well as a major component of many minerals such as limestone. The carbon cycle comprises a sequence of events that are key to making Earth capable of sustaining life. It describes the movement of carbon as it is recycled and reused throughout the biosphere, as well as long-term processes of carbon sequestration (storage) to and release from carbon sinks.
Geomicrobiology is the scientific field at the intersection of geology and microbiology and is a major subfield of geobiology. It concerns the role of microbes on geological and geochemical processes and effects of minerals and metals to microbial growth, activity and survival. Such interactions occur in the geosphere, the atmosphere and the hydrosphere. Geomicrobiology studies microorganisms that are driving the Earth's biogeochemical cycles, mediating mineral precipitation and dissolution, and sorbing and concentrating metals. The applications include for example bioremediation, mining, climate change mitigation and public drinking water supplies.
A biogeochemical cycle, or more generally a cycle of matter, is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth's crust. Major biogeochemical cycles include the carbon cycle, the nitrogen cycle and the water cycle. In each cycle, the chemical element or molecule is transformed and cycled by living organisms and through various geological forms and reservoirs, including the atmosphere, the soil and the oceans. It can be thought of as the pathway by which a chemical substance cycles the biotic compartment and the abiotic compartments of Earth. The biotic compartment is the biosphere and the abiotic compartments are the atmosphere, lithosphere and hydrosphere.
Isotope geochemistry is an aspect of geology based upon the study of natural variations in the relative abundances of isotopes of various elements. Variations in isotopic abundance are measured by isotope-ratio mass spectrometry, and can reveal information about the ages and origins of rock, air or water bodies, or processes of mixing between them.
Crustal recycling is a tectonic process by which surface material from the lithosphere is recycled into the mantle by subduction erosion or delamination. The subducting slabs carry volatile compounds and water into the mantle, as well as crustal material with an isotopic signature different from that of primitive mantle. Identification of this crustal signature in mantle-derived rocks is proof of crustal recycling.
Katrina Jane Edwards was a pioneering geomicrobiologist known for her studies of organisms living below the ocean floor, specifically exploring the interactions between the microbes and their geological surroundings, and how global processes were influenced by these interactions. She spearheaded the Center for Dark Energy Biosphere Investigation (C-DEBI) project at the University of Southern California, which is ongoing. Edwards also helped organize the deep biosphere research community by heading the Fe-Oxidizing Microbial Observatory Project on Loihi Seamount, and serving on several program steering committees involving ocean drilling. Edwards taught at the Woods Hole Oceanographic Institution (WHOI) and later became a professor at the University of Southern California.[1][2]
The Carbon Mineral Challenge is a citizen science project dedicated to accelerating the discovery of carbon-bearing minerals. The program launched in 2015 December with sponsorship from the Deep Carbon Observatory. The project ended in 2019 September, with 31 new carbon-bearing minerals found from 27 locations.
The Deep Earth Carbon Degassing (DECADE) project is an initiative to unite scientists around the world to make tangible advances towards quantifying the amount of carbon outgassed from the Earth's deep interior into the surface environment through naturally occurring processes. DECADE is an initiative within the Deep Carbon Observatory (DCO).
Marine biogeochemical cycles are biogeochemical cycles that occur within marine environments, that is, in the saltwater of seas or oceans or the brackish water of coastal estuaries. These biogeochemical cycles are the pathways chemical substances and elements move through within the marine environment. In addition, substances and elements can be imported into or exported from the marine environment. These imports and exports can occur as exchanges with the atmosphere above, the ocean floor below, or as runoff from the land.
Craig E. Manning is a professor of geology and geochemistry in the Department of Earth, Planetary, and Space Sciences at the University of California, Los Angeles, where he served as department chair between 2009 and 2012. Manning's research interests include water chemistry, thermodynamics, gas chemistry, geochemistry, igneous petrology, and metamorphic petrology.
Dimitri Alexander Sverjensky is a professor in Earth and Planetary Sciences at Johns Hopkins University where his research is focused on geochemistry.
Matthew Schrenk is an associate professor in geomicrobiology at Michigan State University. His research focuses on the diversity, distribution, and activities of microorganisms in the deep subsurface biosphere. His work couples molecular biological approaches and geochemical analyses to investigate microbial ecosystems. Schrenk investigates high pH environments fueled by underground serpentinization reactions between water and certain rock types and hydrothermal vent systems along the ocean floor that are driven by volcanic activity.
Mark Alexander Lever is a microbial ecologist and biogeochemist who studies the role of microorganisms in the global carbon cycle. He is a professor of biogeochemistry and geobiology at the Marine Science Institute of the University of Texas at Austin.
The geochemistry of carbon is the study of the transformations involving the element carbon within the systems of the Earth. To a large extent this study is organic geochemistry, but it also includes the very important carbon dioxide. Carbon is transformed by life, and moves between the major phases of the Earth, including the water bodies, atmosphere, and the rocky parts. Carbon is important in the formation of organic mineral deposits, such as coal, petroleum or natural gas. Most carbon is cycled through the atmosphere into living organisms and then respirated back into the atmosphere. However an important part of the carbon cycle involves the trapping of living matter into sediments. The carbon then becomes part of a sedimentary rock when lithification happens. Human technology or natural processes such as weathering, or underground life or water can return the carbon from sedimentary rocks to the atmosphere. From that point it can be transformed in the rock cycle into metamorphic rocks, or melted into igneous rocks. Carbon can return to the surface of the Earth by volcanoes or via uplift in tectonic processes. Carbon is returned to the atmosphere via volcanic gases. Carbon undergoes transformation in the mantle under pressure to diamond and other minerals, and also exists in the Earth's outer core in solution with iron, and may also be present in the inner core.
Mineral evolution is a recent hypothesis that provides historical context to mineralogy. It postulates that mineralogy on planets and moons becomes increasingly complex as a result of changes in the physical, chemical and biological environment. In the Solar System, the number of mineral species has grown from about a dozen to over 5400 as a result of three processes: separation and concentration of elements; greater ranges of temperature and pressure coupled with the action of volatiles; and new chemical pathways provided by living organisms.
Isabelle Daniel is a mineralogist at the Claude Bernard University Lyon 1 in Lyon, France. She studies minerals under extreme conditions, such as those that exist in Earth's mantle, as well as biosignatures of early life.
The deep carbon cycle is geochemical cycle (movement) of carbon through the Earth's mantle and core. It forms part of the carbon cycle and is intimately connected to the movement of carbon in the Earth's surface and atmosphere. By returning carbon to the deep Earth, it plays a critical role in maintaining the terrestrial conditions necessary for life to exist. Without it, carbon would accumulate in the atmosphere, reaching extremely high concentrations over long periods of time.
The deep biosphere is the part of the biosphere that resides below the first few meters of the surface. It extends down at least 5 kilometers below the continental surface and 10.5 kilometers below the sea surface, at temperatures that may reach beyond 120 °C (248 °F) which is comparable to the maximum temperature where a metabolically active organism has been found. It includes all three domains of life and the genetic diversity rivals that on the surface.
Peter H. Barry is an American geochemist who is an associate scientist in the marine chemistry and geochemistry department at the Woods Hole Oceanographic Institution. He uses noble gases and stable isotopes to understand the volatile history and chemical evolution of Earth, including the dynamic processes of subduction, mantle convection and surface volcanism, which control the redistribution of chemical constituents between the crust and mantle reservoirs. Barry’s main research focus has been on high-temperature geochemistry, crust-mantle interactions and the behavior of volatile fluids in the lithosphere. He also studies crustal systems, the origin of high helium deposits, including hydrocarbon formation and transport mechanisms.
Bénédicte Menez is a French geomicrobiologist and university professor in Earth Sciences at the Institut de Physique du Globe de Paris. In 2012, she received the Irène Joliot-Curie Prize in the “Young Female Scientist” category for her work.
