What is Ocean: Definition and 188 Discussions

The ocean (also the sea or the world ocean) is the body of salt water which covers approximately 71% of the surface of the Earth. It is also "any of the large bodies of water into which the great ocean is divided". A common definition lists five oceans, in descending order by area, the Pacific, Atlantic, Indian, Southern (Antarctic), and Arctic Oceans.Seawater covers approximately 361,000,000 km2 (139,000,000 sq mi) and is customarily divided into several principal oceans and smaller seas, with the ocean as a whole covering approximately 71% of Earth's surface and 90% of the Earth's biosphere. The world ocean contains 97% of Earth's water, and oceanographers have stated that less than 20% of the oceans have been mapped. The total volume is approximately 1.35 billion cubic kilometers (320 million cu mi) with an average depth of nearly 3,700 meters (12,100 ft).As the world's ocean is the principal component of Earth's hydrosphere, it is integral to life, forms part of the carbon cycle, and influences climate and weather patterns. The ocean is the habitat of 230,000 known species, but because much of it is unexplored, the number of species in the ocean is much larger, possibly over two million. The origin of Earth's oceans is unknown; a sizable quantity of water would have been in the material that formed the Earth. Water molecules would have escaped Earth's gravity more easily when it was less massive during its formation due to atmospheric escape. Oceans are thought to have formed in the Hadean eon and may have been the cause for the emergence of life.
There are numerous environmental issues for oceans which include for example marine pollution, overfishing, ocean acidification and other effects of climate change on oceans.
Extraterrestrial oceans may be composed of water or other elements and compounds. The only confirmed large stable bodies of extraterrestrial surface liquids are the lakes of Titan, although there is evidence for oceans' existence elsewhere in the Solar System.

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  1. C

    I Hydrostatics: Pascal's principle and ocean depth

    Hello everyone! I've been learning about hydrostatics and one thing that I've heard is that the pressure is the same throughout confined incompressible fluids, this is one of the reasons hydraulics work, because when you have the same pressure per square meter, you can change the mechanical...
  2. Astronuc

    I Jupiter atmosphere, turbulence and ocean fluid dynamics

    Ocean physics explain cyclones on Jupiter https://phys.org/news/2022-01-ocean-physics-cyclones-jupiter.html Moist convection drives an upscale energy transfer at Jovian high latitudes https://www.nature.com/articles/s41567-021-01458-y...
  3. C

    Lifting power at the bottom of the ocean?

    Hello, I'm a little confused about water pressure at extreme depths. Let's say that you attached a 100 lb. weight to a barrel, and the barrel had barely enough buoyancy to be able to just hold that weight at the surface (see Figure 1.) Then, you took the same barrel and you put it at the...
  4. jim mcnamara

    NOAA resources for primary and secondary schools - ocean currents

    https://www.noaa.gov/education/resource-collections/ocean-coasts/ocean-currents This introduces concepts and then there are links. One link talks about the "Adopt a Drifter" program. A local charter school (primary) became involved with "adopt a drifter", tracking an oceanic buoy. Kids really...
  5. nicolewreyford

    Doppler shift between a moving ship on the ocean and a satellite in LEO

    Summary:: I would like to calculate the Doppler shift for a signal sent by a moving ship to a moving satellite. I want to calculate the frequency observed by an LEO satellite when a signal is transmitted from a moving ship. The LEO satellite has a velocity of 7120m/s and orbits at a height of...
  6. L

    Exploring an Infinite Ocean: Questions & Answers

    Summary:: Ideas concerning an ocean without limit. I asked this question in a philosophy forum and got quite a bit of feedback but it didn't quite answer my initial question. If there was an infinite ocean and I scooped a cup of water out of it, was anything actually taken/lost from the ocean...
  7. T

    Please help me find what 't' is (Plane flying across the Atlantic Ocean)

    Please see below question and formula for Z(t) - position, I differentiate twice to get the below formula for acceleration. But I cannot solve it because of the unknown t... What is t representing in the original equation?
  8. M

    Probe to the Ocean of Enceladus

    Summary:: Speculative question on the feasibility of using a nuclear powered probe to reach the subsurface ocean of Saturn's moon Enceladus. I was thinking about the problem of how to put a probe in the ocean of Enceladus. Enceladus is a moon of Saturn which has some interesting properties. It...
  9. K

    I Freshly Made Plutonium From Outer Space Found On Ocean Floor

    Freshly Made Plutonium From Outer Space Found On Ocean Floor May 13, 2021 [discussion split off from here: https://www.physicsforums.com/threads/what-is-theoretically-the-heaviest-isotope-that-the-r-process-could-produce.1000056/ ]
  10. AN630078

    Thought experiment: How would ocean levels change?

    I am not too sure how to approach this, initially I thought it may be more of a calculus and related rates of change problem, i.e. finding an expression how the volume and height of water change with respect fo time. I do not know whether this is the right idea or how to progress any further...
  11. LCSphysicist

    Electrodynamics problem -- Calculating the resistance of ocean water

    A return path for the current was provided by the ocean itself. Given that the resistivity of seawater is about 0.25 ohm-meter, see if you can show that the resistance of the ocean return would have been much smaller than that of the cable. (Assume that the electrodes immersed in the water were...
  12. Mikkel

    Meridional Heat Transfer - Ocean and Atmosphere

    Hello! I'm currently studying meridional heat transfer, but I'm struggeling to understand the attached figure. I don't understand why the ocean contributes more than the atmosphere near the equator and why it suddenly falls off towards the mid-latitudes. Also, why the atmosphere peaks at...
  13. K

    Why do we add turbulence to the rotating water in our experiment?

    <Mentor moved to Physics> My teacher talks about turbulence (2D and 3D), but I don't quite understand this. How is the turbulence different in the two buckets, and why does my teacher talk about turbulence but not diffusion? Is not diffusion the reason why the dye spreads in the water? I have...
  14. G

    Exploring Balloon Volume in Ocean Descents

    Hey fellow physics enthusiasts, how might the volume of a balloon change as you bring it down deep into the ocean (consider both adiabatic (quick) and equilibrium (slow) descend). Looking for insights what most likely will happen, for simplicity we can start with a thin (##t << R##) elastic...
  15. DaveC426913

    Can Humans Metabolize Alien Life Forms on a Colonized Ocean World?

    I'm writing a science fiction short story about an ocean world with indigenous life, colonized by humans, and I want to check some of my "facts".1. Given the possibility/assumption of panspermia, spreading hydrocarbons and possibly even simple enzymes between systems, is it plausible for a...
  16. A

    Pipe Design to pump sea water from the ocean to a boiler via intermediate tanks

    I am in the process of designing a pumping/piping system for fun, have no experience in this field, but I enjoy learning. I have been using ANSI/ASME codes in the project quite a bit. For the system I am using 4" nom. Schedule 40 316 SS pipe. The reason I selected the pipe is because the...
  17. G

    Negative carbon emissions to fight ocean acidification?

    The IPCC report strongly encouraged not only trying to get our carbon dioxide emissions down to fight climate change, but to go into negative emissions so as to draw the carbon dioxide out of the air (since it's too high as it is). Wouldn't that help to fight ocean acidification too? Because...
  18. BillTre

    Chicxulub Impact: Geologically Instant Ocean Acidification

    This NY Times article discusses findings based on iostopes of Boron in ocean sediments that indicate a geologically instant acidification of the oceans following the Chicxulub impact. The Daccan traps (resulting from an eruption of over 200,000 cubic miles of lava in about a million years)...
  19. A

    Volume of ice needed to mitigate ocean warming since 1871

    According to following study 436 x 10^21 J of energy have been absorbed by the Earth's oceans since 1871. https://www.pnas.org/content/116/4/1126 What thickness of ice covering the globe would be needed to melt in order to absorb this amount of energy, assuming that all energy goes towards the...
  20. S

    Ports versus mileage on the ocean - which cost is most significant?

    For compaines that operate large container ships, which costs are more significant - the costs of being in port or the costs of traveling over the ocean? Is a voyage of, say, 2000 miles about twice as costly as voyage of 1000 miles? Or perhaps the particular ports the ship uses are more...
  21. diogenesNY

    UK Guardian: Flat Earth Ocean Cruise

    The Guardian - Adam Gabbatt @adamgabbatt Thu 10 Jan 2019 01.00 ESTLast modified on Thu 10 Jan 2019 11.02 EST A group of people who believe the Earth is flat have announced their “biggest, boldest, best adventure yet”: a Flat Earth cruise scheduled for 2020. Article continues...
  22. M

    Can we extract energy out of a capacitor in the ocean?

    Hello, sorry about my english it's not my mother tongue. I hope this is the right section to place this. 1. Homework Statement A cylindrical capacitor is placed in the sea so that when a wave comes (the water goes up), the water becomes the capacitors dielectric, when the wave has passed (the...
  23. D

    Ocean acidification and atmospheric carbon

    Hi everyone The following graph shows levels of CO2 in the oceans increasing with atmospheric CO2. https://ocean.si.edu/conservation/acidification/ocean-acidification-graph Given that global temperatures should rise with CO2, is it theoretically possible for the oceans warm to the point...
  24. Jason K

    Writing: Input Wanted Submerged Structures in an Ocean World

    Suppose that there exists a rotating water planet, i.e. a planet with a fairly deep ocean, which contains a large structure of a particular geometry submerged within the ocean. If this structure was assembled within the ocean will it, once it reaches a steady state, rotate at the same rate as...
  25. jedishrfu

    Novel Technology to clean the ocean of plastics

    http://www.upworthy.com/a-dutch-boy-genius-said-he-could-get-the-ocean-to-clean-itself-turns-out-he-s-right This young Dutch inventor is set to solve a major ecological problem cleaning the great garbage patch in the ocean between Hawaii and California in a cost effective and possibly...
  26. T

    Refraction of Ocean waves: Wide Headland vs Narrow

    When a wave encounters the shallow water of a headland the shallow section slows while the deeper section continues traveling at a faster speed. This causes refraction of the wave ray towards the shallower headland section For wave rays encountering perpendicular a shallow headland does...
  27. M

    Is water at the bottom of the ocean oxygen deficient?

    Is water at the bottom of the ocean oxygen deficient? Compared to water at the higher levels.
  28. T

    Refraction Convergence and Amplitude change- Ocean waves

    There are many explanations on the internet, of refraction and convergence of ocean waves entering shallow water around a headland However they all go no deeper than this statement "Where the water is shallow the wave rays converge wave energy is greater where the wave rays spread out the...
  29. D

    Do light and sound waves roll up and break like ocean waves?

    When sea waves approach the shore they roll up and break due to different velocities of water layers formed due to the gradual change in water depth. The highest wave peaks move faster than all other layers and thus falls down. All other layers fall the same way but in a delay. this ends up with...
  30. IgnorantofPhysics

    B Countering the Movement of the Ocean & different size boats/ships

    I’ve been on cruise ships and recreational boats. But, that’s not something I do every weekend. That’s just an occasional thing. On the smaller boats, I can feel the ebb and flow of being on the ocean more noticeably. On the cruise ships, I have to be real still and off in a quiet place to...
  31. Astronuc

    Mapping the ocean floor - bathymetry survey

    The search for the missing aircraft of flight MH370 has yielded information on the region of the Indian Ocean under survey. http://www.upworthy.com/amp/they-looked-for-missing-flight-mh370-for-3-years-heres-what-they-found-instead...
  32. J

    Getting energy from deep ocean pressure

    Let's say we would take a pipe made of some very strong material, and connect it to the ocean at the deepest level possible. For example 500 meters. Then we would dig a huge area on land, again, as deep as possible. Lead the pipe to the lowest level of this huge basin we created and then use...
  33. lpetrich

    B Ocean planets? Desert planets?

    Let's first look at our homeworld, to use as a reference. The Earth's surface water has a mass about 0.00023 times the Earth's total mass, with the planetary ocean having 96.5% of it. The ocean has a mean depth of 3.8 km, and they cover 71% of the Earth's surface, giving a planetwide average of...
  34. T

    Is the water pressure below ocean waves constant?

    If you are stationary say 10m below the ocean surface does the water pressure at your location vary with the waves. For example: When a wave crest is above you than means perhaps 12m of water is above you. Then a few seconds later a trough is above you so only 8m of water is above you. So you...
  35. P

    Kinetic energy in ocean current

    Homework Statement Consider an Ocean Current flowing at 2.5 m/s. a) How much energy is contained in a cubical block of water 1m on the side. (The density of the water is about 1030kg/m^3.) b) If the flow is perpendicular to one of the cube faced, what is the rate at which current flow carries...
  36. Robert House

    What is the impact of storms on submarines?

    Here is a scenario to further explain. Let's say I am traveling inside of a submarine. I travel within a depth of 100 to 600 feet deep or 4 to 19 atmospheres. How would I and my submarine be affected if there were a hurricane, tsunami, or hurricane above the ocean. Furthermore, does the...
  37. Seth Newman

    Ship Bobbing in the Ocean (Frequency Problem)

    Homework Statement "SpaceForce One" is a perfectly spherical ship of mass 2.5·10^6 kg and Radius 42 meters bobbing up and down in calm seas on Earth At what frequency does SpaceForce ship bob? Homework Equations None explicitly given. The Attempt at a Solution We approached this problem in a...
  38. P

    How Ocean Waves Affect Beaches

    Hi I am currently looking for a topic to write my essay on. My first idea was to talk about how waves altered in different beaches. (With this I mean the shape of the waves) I don't know much about waves and I can't seem to find good info on the internet. If you think there isn't much to write...
  39. V

    I Why exactly does the ocean bulge on both sides of the Earth?

    Here's what my prof says: "Define F_{mean} to be the mean force, F_close to be the force on the side of the Earth closer to the moon, and F_far to be the force on the side of the Earth furthest away from the moon. On the closer side the net force is F_close - F_mean > 0 On the further side the...
  40. ATY

    I Understanding Lyapunov Exponent: Why Do We Use an Exponential Function?

    Hey guys, I need your help. I am not sure if this is the right part of the forum to ask this question. So I started reading papers about the Lyapunov Exponent, but there is something I do not understand in the formula. Why ? It seems logical that we want because we want to get the Exponent...
  41. ATY

    Drogued Drifters: What Does It Mean?

    Hey guys, I am not sure if this is the right forum for this question. So I started to read some papers for my master thesis in environmental physics (no idea if this is the correct translation) and there they talked about "drogued" drifters and "undrogued" drifters in the ocean, from which they...
  42. T

    What solution can simulate ocean acidification for a classroom demonstration?

    I would like to do a classroom demonstration using plaster of paris (or something similar) shells dissolving in a low pH solution, simulating ocean acidification. I would like the reaction to happen quite quickly in front of the classroom. What solution could I use to dissolve plaster of paris...
  43. V

    Ocean Word Problem: Find Equation

    Homework Statement The water depth in a harbour is 21m at high tide and 11m at low tide. One cycle is completed approximately every 12 hrs. Find an equation. Homework EquationsThe Attempt at a Solution The answer to this problem is y = 5sin 30 (t-3) + 16 A = (M - m) / 2 = (21-11) / 2 = 5...
  44. Tom MS

    Does Wave Refraction Change Wave Direction or Alignment

    I can't seem to find anything online that talks about this distinction. I understand how when the water gets shallower that part of the wave gets slowed down so the overall alignment parallels with the shore. However, I wouldn't think that would change the actual direction of the wave. I need a...
  45. T

    Can we use pressure to power an unmanned submersible for deep ocean exploration?

    This is a slight twist because I'm not looking to establish a colony under water, however my interest is still with ocean exploration. Allow me to ask the question: Could we design an unmanned submersible exploration machine that can dive to the depths of our deepest capabilities with a sub...
  46. A

    Hurricane reduction through ocean surface cooling

    Old article: http://edition.cnn.com/2009/TECH/science/08/28/hurricanes.gates.gray/ What do you guys think? Where do you see this project going? The official word is that it's not being publicly funded. But if there was even a 10% chance it would work, I see governments lining up at the...
  47. A

    Qualitative description of unbounded ocean system

    Homework Statement [/B] a) Suppose that you have the unbounded ocean show in the picture, where h = 2000 m. At t = 0, the system is allowed to relax. Make a qualitative description of its evolution and final state if i) L = 100 m, and ii) L = 10,000 m. b) At what speed should an observer...
  48. newjerseyrunner

    How diverse would a subterranean ocean be?

    I was thinking about Europa today and considering how life might exist on it. Spacecraft and models have shown that all of the ingredients for life is there, but I was wondering about the evolution of life after it forms. Earth had a lot of very diverse environments, which greatly accelerated...
  49. CollinsArg

    What would happen if an iron sinks on the ocean? Velocity

    if I throw a ball of iron on the ocean, the velocity in which it will sink will be lower at the beginning and higher getting near the deepest part of it? As it may be forced by the pressure of water? (the weight of water)