View source for Marine chemistry

{{Short description|Chemistry of oceans and seas}}
{{Redirect|Marine chemist|the National Fire Protection Association professional certification|Confined space#Entry certification}}
{| class="wikitable" style="float: right; margin: 0 0 1em 1em;"
|+'''Total Molar Composition of Seawater (Salinity = 35)'''<ref>{{
Cite book
|author=DOE
|year=1994
|chapter-url=http://cdiac.esd.ornl.gov/ftp/cdiac74/chapter5.pdf
|title=Handbook of methods for the analysis of the various parameters of the carbon dioxide system in sea water
|publisher=ORNL/CDIAC-74
|version=2
|editor1=A.G. Dickson |editor2=C. Goyet
|chapter=5
}}
{{webarchive|url=https://web.archive.org/web/20150718025533/http://cdiac.esd.ornl.gov/ftp/cdiac74/chapter5.pdf}}</ref>
|-
! Component !! Concentration (mol/kg)
|-
| '''[[Water (molecule)|{{chem|H|2|O}}]]''' || 53.6
|-
| '''[[Chloride|{{chem|Cl|-}}]]''' || 0.546
|-
| '''[[Sodium|{{chem|Na|+}}]]''' || 0.469
|-
| '''[[Magnesium|{{chem|Mg|2+}}]]''' || 0.0528
|-
| '''[[sulfate|{{chem|SO|2-|4}}]]''' || 0.0282
|-
| '''[[Calcium|{{chem|Ca|2+}}]]''' || 0.0103
|-
| '''[[Potassium|{{chem|K|+}}]]''' || 0.0102
|-
| '''[[Total inorganic carbon|C<sub>T</sub>]]''' || 0.00206
|-
| '''[[Bromide|{{chem|Br|-}}]]''' || 0.000844
|-
| '''[[Total boron|B<sub>T</sub>]]''' (total boron) || 0.000416
|-
| '''[[Strontium|{{chem|Sr|2+}}]]''' || 0.000091
|-
| '''[[Fluoride|{{chem|F|-}}]]''' || 0.000068
|}

'''Marine chemistry''', also known as '''ocean chemistry''' or '''chemical oceanography''', is the study of the chemical composition and processes of the world’s oceans, including the interactions between seawater, the atmosphere, the seafloor, and marine organisms.<ref name=":3">{{Cite book |last=Pilson |first=Michael E. Q. |url=https://www.cambridge.org/core/books/an-introduction-to-the-chemistry-of-the-sea/3F3142B6C163A06BF0AD513D82A3EF18 |title=An Introduction to the Chemistry of the Sea |date=2012 |publisher=Cambridge University Press |isbn=978-0-521-88707-6 |edition=2 |location=Cambridge |doi=10.1017/cbo9781139047203}}</ref> This field encompasses a wide range of topics, such as the cycling of elements like carbon, nitrogen, and phosphorus, the behavior of trace metals, and the study of gases and nutrients in marine environments. Marine chemistry plays a crucial role in understanding global [[Biogeochemical cycle|biogeochemical cycles]], [[Ocean current|ocean circulation]], and the effects of human activities, such as pollution and climate change, on oceanic systems.<ref name=":3" /> It is influenced by [[plate tectonics]] and [[seafloor spreading]], [[turbidity]], [[Ocean current|currents]], [[sediment]]s, [[pH]] levels, atmospheric constituents, metamorphic activity, and ecology. 

The impact of human activity on the chemistry of the Earth's oceans has increased over time, with pollution from industry and various land-use practices significantly affecting the oceans. Moreover, increasing levels of [[Carbon dioxide in Earth's atmosphere|carbon dioxide in the Earth's atmosphere]] have led to [[ocean acidification]], which has negative effects on marine ecosystems. The international community has agreed that restoring the chemistry of the oceans is a priority, and efforts toward this goal are tracked as part of [[Sustainable Development Goal 14]].

Due to the interrelatedness of the ocean, chemical oceanographers frequently work on problems relevant to [[physical oceanography]], [[geology]] and [[geochemistry]], [[biology]] and [[biochemistry]], and [[atmospheric science]]. Many of them are investigating [[biogeochemical cycle]]s, and the [[marine carbon cycle]] in particular attracts significant interest due to its role in [[carbon sequestration]] and [[ocean acidification]].<ref>{{Cite web |last=Gillis |first=Justin |date=2012-03-02 |title=Pace of Ocean Acidification Has No Parallel in 300 Million Years, Paper Says |url=https://green.blogs.nytimes.com/2012/03/02/pace-of-ocean-acidification-has-no-parallel-in-300-million-years-paper-finds/ |access-date=2020-04-28 |website=Green Blog |language=en-US}}</ref> Other major topics of interest include [[analytical chemistry]] of the oceans, [[marine pollution]], and [[anthropogenic climate change]].

==Organic compounds in the oceans==

=== Dissolved Organic Matter (DOM) ===
[[File:Forms of organic matter.webp|thumb|Ocean organic matters]]
DOM is a critical component of the ocean's carbon pool and includes many molecules such as amino acids, sugars, and lipids. It represents about 90% of the total organic carbon in marine environments.<ref>{{Cite book |title=Biogeochemistry of marine dissolved organic matter |date=2002 |publisher=Academic Press |isbn=978-0-12-323841-2 |editor-last=Hansell |editor-first=Dennis A. |location=Amsterdam ; Boston |editor-last2=Carlson |editor-first2=Craig A.}}</ref> [[Colored dissolved organic matter]] (CDOM) is estimated to range from 20-70% of the carbon content of the oceans, being higher near river outlets and lower in the open ocean.<ref name="Coble">{{cite journal | last1 = Coble | first1 = Paula G. | year = 2007 | title = Marine Optical Biogeochemistry: The Chemistry of Ocean Color | journal = Chemical Reviews | volume = 107 | issue = 2| pages = 402–418 | doi =  10.1021/cr050350+| pmid = 17256912 }}</ref> DOM can be recycled and put back into the food web through a process called microbial loop which is essential for nutrient cycling and supporting primary productivity.<ref>{{Cite journal |last=Azam |first=F |last2=Fenchel |first2=T |last3=Field |first3=Jg |last4=Gray |first4=Js |last5=Meyer-Reil |first5=La |last6=Thingstad |first6=F |date=1983 |title=The Ecological Role of Water-Column Microbes in the Sea |url=http://www.int-res.com/articles/meps/10/m010p257.pdf |journal=Marine Ecology Progress Series |language=en |volume=10 |pages=257–263 |doi=10.3354/meps010257 |issn=0171-8630}}</ref> It also plays a vital role in the global regulation of oceanic carbon storage, as some forms resist microbial degradation and may exist within the ocean for centuries.<ref>{{Cite journal |last=Hansell |first=Dennis |last2=Carlson |first2=Craig |last3=Repeta |first3=Daniel |last4=Schlitzer |first4=Reiner |date=2009-12-01 |title=Dissolved Organic Matter in the Ocean: A Controversy Stimulates New Insights |url=https://tos.org/oceanography/article/dissolved-organic-matter-in-the-ocean-a-controversy-stimulates-new-insights |journal=Oceanography |volume=22 |issue=4 |pages=202–211 |doi=10.5670/oceanog.2009.109|hdl=1912/3183 |hdl-access=free }}</ref> Marine life is similar mainly in biochemistry to terrestrial organisms, and is the most prolific source of [[halocarbon|halogenated organic compounds]].<ref>{{cite journal | last1 = Gribble | first1 = Gordon W. | year = 2004 | title = Natural Organohalogens: A New Frontier for Medicinal Agents? | journal = Journal of Chemical Education | volume = 81 | issue = 10| page = 1441 | doi = 10.1021/ed081p1441 | bibcode = 2004JChEd..81.1441G }}</ref>  

=== Particulate Organic Matter (POM) ===
POM includes of large organic particles, such as organisms, fecal pellets, and detritus, which settle through the water column. It is a major component of the biological pump, a process by which carbon is transferred from the surface ocean to the deep sea. As POM sinks, it decomposes by bacterial activity , releasing nutrients and carbon dioxide. The refractory POM fraction can settle on the ocean floor and make relevant contributions to carbon sequestration over a very long period of time<ref>{{Cite journal |last=Hedges |first=John I. |last2=Baldock |first2=Jeffrey A. |last3=Gélinas |first3=Yves |last4=Lee |first4=Cindy |last5=Peterson |first5=Michael |last6=Wakeham |first6=Stuart G. |date=2001-02-15 |title=Evidence for non-selective preservation of organic matter in sinking marine particles |url=https://www.nature.com/articles/35057247 |journal=Nature |language=en |volume=409 |issue=6822 |pages=801–804 |doi=10.1038/35057247 |issn=0028-0836}}</ref> 

==Chemical ecology of extremophiles==
The ocean is home to a variety of marine organisms known as [[extremophile]]s – organisms that thrive in extreme conditions of temperature, pressure, and light availability. Extremophiles inhabit many unique habitats in the ocean, such as [[Hydrothermal vent|hydrothermal vents]], black smokers, [[Cold seep|cold seeps]], hypersaline regions, and [[Sea ice brine pocket|sea ice brine pockets]]. Some scientists have speculated that life may have evolved from hydrothermal vents in the ocean.[[File:Deep_Sea_Vent_Chemistry_Diagram.svg|thumb|upright=1.75|A diagram showing ocean chemistry around deep sea [[hydrothermal vent]]s|alt=]]In hydrothermal vents and similar environments, many extremophiles acquire energy through [[Chemoautotroph|chemoautotrophy]], using chemical compounds as energy sources, rather than light as in [[Photoautotrophism|photoautotrophy]]. Hydrothermal vents enrich the nearby environment in chemicals such as [[Sulfur|elemental sulfur]], [[Hydrogen gas|H<sub>2</sub>]], [[Hydrogen sulfide|H<sub>2</sub>S]], [[Iron|Fe<sup>2+</sup>]], and [[methane]]. Chemoautotrophic organisms, primarily prokaryotes, derive energy from these chemicals through [[Redox|redox reactions]]. These organisms then serve as food sources for higher [[Trophic level|trophic levels]], forming the basis of unique ecosystems.

Several different metabolisms are present in hydrothermal vent ecosystems. Many marine microorganisms, including ''Thiomicrospira'', ''Halothiobacillus'', and ''[[Beggiatoa]]'', are capable of oxidizing sulfur compounds, including elemental sulfur and the often toxic compound H<sub>2</sub>S. H<sub>2</sub>S is abundant in hydrothermal vents, formed through interactions between seawater and rock at the high temperatures found within vents. This compound is a major energy source, forming the basis of the [[sulfur cycle]] in hydrothermal vent ecosystems. In the colder waters surrounding vents, sulfur-oxidation can occur using oxygen as an [[electron acceptor]]; closer to the vents, organisms must use alternate metabolic pathways or utilize another electron acceptor, such as nitrate. Some species of ''Thiomicrospira'' can utilize thiosulfate as an electron donor, producing elemental sulfur. Additionally, many marine microorganisms are capable of iron-oxidation, such as ''[[Mariprofundus ferrooxydans]]''. Iron-oxidation can be oxic, occurring in oxygen-rich parts of the ocean, or anoxic, requiring either an electron acceptor such as nitrate or light energy. In iron-oxidation, Fe(II) is used as an [[electron donor]]; conversely, iron-reducers utilize Fe(III) as an electron acceptor. These two metabolisms form the basis of the iron-redox cycle and may have contributed to [[Banded iron formation|banded iron formations]].

At another extreme, some marine extremophiles inhabit sea ice brine pockets where temperature is very low and salinity is very high. Organisms trapped within freezing sea ice must adapt to a rapid change in salinity up to 3 times higher than that of regular seawater, as well as the rapid change to regular seawater salinity when ice melts. Most brine-pocket dwelling organisms are photosynthetic, therefore, these microenvironments can become hyperoxic, which can be toxic to its inhabitants. Thus, these extremophiles often produce high levels of antioxidants.<ref>{{Cite web |title=Chemoautotrophy at Deep-Sea Vents: Past, Present, and Future {{!}} Oceanography |url=https://tos.org/oceanography/article/chemoautotrophy-at-deep-sea-vents-past-present-and-future |access-date=2024-02-08 |website=tos.org |doi=10.5670/oceanog.2012.21}}</ref>

==Plate tectonics==
[[File:MgCaRatioChanges.jpg|alt=|thumb|upright=1.5|Magnesium to calcium ratio changes associated with hydrothermal activity at mid-ocean ridge locations]]

Seafloor spreading on [[mid-ocean ridge]]s is a global scale [[Ion exchange|ion-exchange]] system.<ref name=":0">{{cite journal | last1 = Stanley | first1 = S.M. | last2 = Hardie | first2 = L.A. | year = 1999 | title = Hypercalcification: paleontology links plate tectonics and geochemistry to sedimentology | journal = GSA Today | volume = 9 | issue = 2| pages = 1–7 }}</ref> Hydrothermal vents at spreading centers introduce various amounts of [[iron]], [[sulfur]], [[manganese]], [[silicon]] and other elements into the ocean, some of which are recycled into the [[Oceanic crust|ocean crust]]. [[Helium-3]], an isotope that accompanies volcanism from the mantle, is emitted by hydrothermal vents and can be detected in plumes within the ocean.<ref>{{Cite journal|last=Lupton|first=John|date=1998-07-15|title=Hydrothermal helium plumes in the Pacific Ocean|journal=Journal of Geophysical Research: Oceans|volume=103|issue=C8|pages=15853–15868|doi=10.1029/98jc00146|issn=0148-0227|bibcode=1998JGR...10315853L|doi-access=free}}</ref>

Spreading rates on mid-ocean ridges vary between 10 and 200&nbsp;mm/yr. Rapid spreading rates cause increased [[basalt]] reactions with seawater. The [[magnesium]]/[[calcium]] ratio will be lower because more magnesium ions are being removed from seawater and consumed by the rock, and more calcium ions are being removed from the rock and released to seawater. Hydrothermal activity at ridge crest is efficient in removing magnesium.<ref name=":2">{{Cite journal|last1=Coggon|first1=R. M.|last2=Teagle|first2=D. A. H.|last3=Smith-Duque|first3=C. E.|last4=Alt|first4=J. C.|last5=Cooper|first5=M. J.|date=2010-02-26|title=Reconstructing Past Seawater Mg/Ca and Sr/Ca from Mid-Ocean Ridge Flank Calcium Carbonate Veins|journal=Science|language=en|volume=327|issue=5969|pages=1114–1117|doi=10.1126/science.1182252|pmid=20133522|issn=0036-8075|bibcode=2010Sci...327.1114C|s2cid=22739139}}</ref> A lower Mg/Ca ratio favors the precipitation of low-Mg calcite [[Polymorphism (materials science)|polymorphs]] of [[calcium carbonate]] ([[calcite sea]]s).<ref name=":0" />

Slow spreading at mid-ocean ridges has the opposite effect and will result in a higher Mg/Ca ratio favoring the precipitation of aragonite and high-Mg calcite polymorphs of calcium carbonate ([[aragonite sea]]s).<ref name=":0" />

Experiments show that most modern high-Mg calcite organisms would have been low-Mg calcite in past calcite seas,<ref name=":1">{{Cite journal|last=Ries|first=Justin B.|date=2004|title=Effect of ambient Mg/Ca ratio on Mg fractionation in calcareous marine invertebrates: A record of the oceanic Mg/Ca ratio over the Phanerozoic|journal=Geology|language=en|volume=32|issue=11|pages=981|doi=10.1130/G20851.1|issn=0091-7613|bibcode=2004Geo....32..981R}}</ref> meaning that the Mg/Ca ratio in an organism's skeleton varies with the Mg/Ca ratio of the seawater in which it was grown.

The mineralogy of [[Coral Reef|reef-building]] and sediment-producing organisms is thus regulated by chemical reactions occurring along the mid-ocean ridge, the rate of which is controlled by the rate of sea-floor spreading.<ref name=":2" /><ref name=":1" />

== Human impacts ==

=== Marine pollution ===
{{Excerpt|Marine pollution|paragraphs=1-2|file=no}}

===Climate change===
{{Further|Effects of climate change on oceans#Chemical effects}}
Increased [[carbon dioxide]] levels, mostly from burning [[Fossil fuel|fossil fuels]], are changing ocean chemistry. [[Global warming]] and changes in [[salinity]]<ref>{{Cite web |title=Ocean salinity: Climate change is also changing the water cycle |url=https://usys.ethz.ch/en/news-events/news/archive/2020/09/new-study-of-ocean-salinity-finds-substantial-amplification-of-the-global-water-cycle.html |access-date=2022-05-22 |website=usys.ethz.ch |language=en}}</ref> have significant implications for the [[ecology]] of marine [[Environment (biophysical)|environment]]s.<ref>{{cite journal | last1 = Millero | first1 = Frank J. | year = 2007 | title = The Marine Inorganic Carbon Cycle | journal = Chemical Reviews | volume = 107 | issue = 2| pages = 308–341 | doi = 10.1021/cr0503557 | pmid = 17300138 }}</ref>

==== Acidification ====
{{Excerpt|Ocean acidification|paragraphs=1-2|file=no}}

==== Deoxygenation ====
{{Excerpt|Ocean deoxygenation}}

== History ==
[[File:HMS Challenger (1858).jpg|thumb|HMS Challenger (1858)]]
Early inquiries about marine chemistry usually concerned the origin of [[salinity]] in the ocean, including work by [[Robert Boyle]]. Modern chemical oceanography began as a field with the 1872–1876 [[Challenger expedition|''Challenger'' expedition]], led by the British Royal Navy which made the first systematic measurements of ocean chemistry. The chemical analysis of these samples providing the first systematic study of the composition of seawater was conducted by John Murray and George Forchhammer, leading to a better understanding of elements like chloride, sodium, and sulfate in ocean waters<ref>{{Cite book |last=Thomson |first=C. Wyville |url=http://dx.doi.org/10.5962/bhl.title.39690 |title=Report on the scientific results of the voyage of H.M.S. Challenger during the years 1873-76 under the command of Captain George S. Nares and the late Captain Frank Tourle Thomson |last2=Murray |first2=John |last3=Nares |first3=George S. |last4=Thomson |first4=Frank Tourle |date=1889}}</ref>  

The early 20th century saw significant advancements in marine chemistry, particularly with more accurate analytical techniques. Scientists like Martin Knudsen created the Knudsen Bottle, an instrument used to collect water samples from different ocean depths.<ref>{{Cite journal |last=Carpenter |first=James H. |date=1966 |title=NEW MEASUREMENTS OF OXYGEN SOLUBILITY IN PURE AND NATURAL WATER1 |url=https://aslopubs.onlinelibrary.wiley.com/doi/10.4319/lo.1966.11.2.0264 |journal=Limnology and Oceanography |language=en |volume=11 |issue=2 |pages=264–277 |doi=10.4319/lo.1966.11.2.0264 |issn=0024-3590}}</ref> Over the past three decades (1970s, 19802, and 1990s), a comprehensive evaluation of advancements in chemical oceanography was compiled through a National Science Foundation initiative known as Futures of Ocean Chemistry in the United States (FOCUS). This project brought together numerous prominent chemical oceanographers, marine chemists, and geochemists to contribute to the FOCUS report.  

After World War II, advancements in geochemical techniques propelled marine chemistry into a new era. Researchers began using isotopic analysis to study ocean circulation and the carbon cycle. Roger Revelle and Hans Suess pioneered using radiocarbon dating to investigate oceanic carbon reservoirs and their exchange with the atmosphere.<ref>{{Cite journal |last=Revelle |first=Roger |last2=Suess |first2=Hans E. |date=1957-01-01 |title=Carbon Dioxide Exchange Between Atmosphere and Ocean and the Question of an Increase of Atmospheric CO2 during the Past Decades |url=https://account.a.tellusjournals.se/index.php/su-j-tadmo/article/view/3628 |journal=Tellus A: Dynamic Meteorology and Oceanography |volume=9 |issue=1 |pages=18–27 |doi=10.3402/tellusa.v9i1.9075 |issn=1600-0870}}</ref> 

Since the 1970s, the development of highly sophisticated instruments and computational models has revolutionized marine chemistry. Scientists can now measure [[Trace metal|trace metals]], [[Organic compound|organic compounds]], and isotopic ratios with unprecedented precision. Studies of marine biogeochemical cycles, including the [[Carbon cycle|carbon]], [[Nitrogen cycle|nitrogen]], and [[Sulfur cycle|sulfur cycles]], have become an area of interest to understand [[Climate change|global climate change]]. The use of remote sensing technology and global ocean observation programs, such as the International Geosphere-Biosphere Programme (IGBP), has provided large-scale data on ocean chemistry, allowing scientists to monitor [[ocean acidification]], [[deoxygenation]], and other critical issues affecting the marine environment.<ref>{{Cite journal |last=Falkowski |first=P. |last2=Scholes |first2=R. J. |last3=Boyle |first3=E. |last4=Canadell |first4=J. |last5=Canfield |first5=D. |last6=Elser |first6=J. |last7=Gruber |first7=N. |last8=Hibbard |first8=K. |last9=Högberg |first9=P. |last10=Linder |first10=S. |last11=Mackenzie |first11=F. T. |last12=Moore III |first12=B. |last13=Pedersen |first13=T. |last14=Rosenthal |first14=Y. |last15=Seitzinger |first15=S. |date=2000-10-13 |title=The Global Carbon Cycle: A Test of Our Knowledge of Earth as a System |url=https://www.science.org/doi/10.1126/science.290.5490.291 |journal=Science |language=en |volume=290 |issue=5490 |pages=291–296 |doi=10.1126/science.290.5490.291 |issn=0036-8075}}</ref> <!--This is a good source for expanding this section: https://www.ncbi.nlm.nih.gov/books/NBK208828/ -->

== Tools used for analysis ==
Chemical oceanographers collect and measure chemicals in seawater, using the standard toolset of [[analytical chemistry]] as well as instruments like [[pH meter]]s, [[electrical conductivity meter]]s, [[fluorometer]]s, and dissolved CO₂ meters. Most data are collected through shipboard measurements and from autonomous [[Float (oceanographic instrument platform)|floats or buoys]], but [[remote sensing]] is used as well. On an oceanographic [[research vessel]], a [[CTD (instrument)|CTD]] is used to measure [[electrical conductivity]], [[temperature]], and [[pressure]],<ref>{{Cite web |title=Waveland Press - Introduction to Physical Oceanography, Third Edition, by John A. Knauss, Newell Garfield |url=https://www.waveland.com/browse.php?t=504 |access-date=2024-10-13 |website=www.waveland.com}}</ref> and is often mounted on a [[rosette sampler|rosette]] of [[Nansen bottle]]s to collect seawater for analysis.<ref>{{Cite report |url=https://repository.oceanbestpractices.org/handle/11329/249 |title=Guide to best practices for ocean CO2 measurement. |last=Dickson |first=A.G. |last2=et |first2=al |date=2007 |publisher=[object Object] |doi=10.25607/obp-1342}}</ref> Sediments are commonly studied with a [[box corer]] or a [[sediment trap]], and older sediments may be recovered by [[scientific drilling]]. 
[[File:Coast Guard deploys Autonomous Underwater Vehicle for Arctic science mission 140820-G-ZR723-001.jpg|thumb|Autonomous Underwater Vehicle (AUV)]]
Advanced analytical equipment such as mass spectrometers and chromatographs are applied to detect trace elements, isotopes, and organic compounds. This allows for precisely measuring nutrients, gases, and pollutants in marine environments.<ref>{{Cite web |date=2007-02-11 |title=Aquatic Photosynthesis {{!}} Princeton University Press |url=https://press.princeton.edu/books/paperback/9780691115511/aquatic-photosynthesis?srsltid=AfmBOoqiS4L0_xL_bx8QS3eqvHgA95IqJkNfssg2eol2BXSYED-AsKm9 |access-date=2024-10-13 |website=press.princeton.edu |language=en}}</ref> In recent years, [[Autonomous underwater vehicle|autonomous underwater vehicles]] (AUVs) and remote sensing technology have enabled continuous, large-scale ocean chemistry monitoring, particularly for tracking changes in ocean acidification and nutrient cycles.<ref>{{Cite journal |last=George |first=Robert A. “Tony” |date=2006 |title=Advances in AUV remote-sensing technology for imaging deepwater geohazards |url=http://library.seg.org/doi/10.1190/1.2405333 |journal=The Leading Edge |language=en |volume=25 |issue=12 |pages=1478–1483 |doi=10.1190/1.2405333 |issn=1070-485X}}</ref>

==Marine chemistry on other planets and their moons==
The chemistry of the [[Europa_(moon)#Subsurface_ocean|subsurface ocean of Europa]] may be Earthlike.<ref>{{Cite web |last=Greicius |first=Tony |date=2016-05-16 |title=Europa's Ocean May Have An Earthlike Chemical Balance |url=http://www.nasa.gov/feature/jpl/europas-ocean-may-have-an-earthlike-chemical-balance |access-date=2022-05-22 |website=NASA}}</ref> The [[Enceladus#Subsurface_water_ocean|subsurface ocean of Enceladus]] vents hydrogen and carbon dioxide to space.<ref>{{Cite web |title=The Chemistry of Enceladus' Plumes: Life or Not? |url=https://astrobiology.nasa.gov/news/clues-in-the-chemistry-of-enceladus-plumes/}}</ref>

== See also ==

* [[Global Ocean Data Analysis Project]]
* [[Oceanography]]
* [[Physical oceanography]]
* [[World Ocean Atlas]]
* [[Seawater]]
* [[RISE project]]

{{Portal bar|Chemistry|Geography|Science|Oceans}}

==References==
{{Reflist}}

{{Authority control}}
{{Branches of chemistry}}

[[Category:Chemical oceanography]]
[[Category:Oceanographical terminology]]
[[Category:Geochemistry]]