Talk:Earth science

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[edit] List of Earth Science topics

The list of Earth Science topics - this is at risk of just becoming one huge list of anything that's related. Should we perhaps weed it down only to include the Earth Science disciplines (i.e. geology, oceanography, geochemistry, geophysics etc)? cferrero

This isn't my area, but I suggest you Be bold in updating pages :-) -- Tarquin 17:50 Feb 21, 2003 (UTC)

I agree that a list of quite specialised discliplines (-ologies) is unhelpful here, especially without any context i.e. general field under which they fall. These lists of topics need at least to be organised into which sphere of the Earth they apply to (i.e. geosphere, hydrosphere, atmosphere, cryosphere etc.) or possibly removed to pages covering that general area. Otherwise people new to this field will just get put off.

Since no-one objected to this suggestion above, I'll have a go. You can all pull me apart afterwards ;) Tonderai 18:51, 3 Dec 2003 (UTC)

These are the aspects changed:

• Position Earth Science as a subset of planetary science (which covers all planets), and a special case because it is the only known life-bearing planet.
• Introducing the major topic areas based on the '-spheres' of the Earth - I think this is the clearest way to set out the main areas. Tonderai 19:39, 3 Dec 2003 (UTC)
• Also introduced major areas of systems approaches to Earth science

Hopefully I've introduced some kind of logical framework to this now, whether it is the right one I don't know. Should provoke some debate anyway. Also, the subject list is heavily biased towards geology, and many of the links are non-existant or very short stubs. I think this area needs some work ;) Tonderai 21:58, 3 Dec 2003 (UTC)

I removed It is analogous to the term "Life Science" because it isn't. Life sciences includes things like optometry and psychology. Earth sciences does not. Source: [1]. Angela 18:18, Sep 19, 2003 (UTC)

Should we actually title a list "partial list of"? Surely we should put "list" if we aspire to list all (and put a note in talk so the rest of us can fill them in) or if it is intended to stay selective "list of major"... or whatever // (talk)--BozMo 19:59, 10 May 2004 (UTC)

[edit] Formatting issue with Opera

Hi: In Opera 7, the top of the Earth Science page (language listing) spills into the logo - I don't know that this is an editable issue but may be more of a coding issue - haven't checked out many other pages but the couple of others I viewed seemed to be ok. Jules (julian@jrickards.ca.nospam)

[edit] Earth science and geology

To me, these two names are synonyms, just like bioscience and biology (geology = Earth study/science). I was always tought that atmospheric sciences and all that was a category of geology. When did this change, who chose the name and why? --Friðrik Bragi Dýrfjörð 10:28, 21 October 2005 (UTC)

• It's quite possible to be an earth scientist, work in an earth sciences department, be typing on a computer in one right now in fact, and not be a geologist! Mineralogy and mineral physics, for instance, has much more in common with solid-state physics and inorganic/crystal chemistry, particularly at the theoretical end of the subject (we publish in Physical Review B, Journal of Physical Chemistry, Chemical Physics Letters, Acta Cryst... not in geological journals, which is a decent rule of thumb for working out where the boundaries are crossed; in fact, the mineralogy degree at the University of Cambridge crosses over with the Materials Science course, not with the Geological Sciences course (which isn't a pre-requisite or even very helpful for the mineralogy courses). Of course, there is substantial overlap with the mainstream of the geological sciences, particularly in mantle chemistry (eg the olivine-spinel transition and the 410 discontinuity in seismology), but any field which tries to embrace atmospheric chemistry, deep-earth seismology, paleontology, petrology and fundamental solid-state physics (ferro/piezo/pyro-electricity, elasticity, percolation theories of radiation damage, etc etc etc) is necessarily going to be an extremely broad church. -- sorry, no user account, 24th October 2005
  • I understand the difference, but the naming is terrible. You see, when you say: "It's quite possible to be an earth scientist, work in an earth sciences department, be typing on a computer in one right now in fact, and not be a geologist!", you are practically stating that an earth scientist is not the same thing as earth scientist, because earth-science = geo-logy. It's like making physics a category of interaction sciences or something similarly stupid. The only reason you see a difference is because historically geologists where just people that gathered rocks and named them. There is no reason to make it a subcategory of earth science (which either way, is bad naming), just because the science has change dramatically in the last 50 years. We didn't change the name of physics because we can use computer simulation and math alone to study things, we just talk about experimental and theoretical physics. --Friðrik Bragi Dýrfjörð 17:03, 1 November 2005 (UTC)
    • Actually, if we are being pedantic, "-logy" doesn't mean " Science"; it means " words". Geology is "Earth-words", words about the Earth. Similarly, "-graphy" means " pictures" or " writing". Geography could either mean "Earth-pictures", pictures of the Earth, or "Earth-writing", written treatises about the Earth. Physics is something else entirely; that term didn't even exist (or at least meant something completely different) until at least the mid 19^th century. Thomas Young was still using the term "Natural Philosophy" over 150 years after Isaac Newton published the Philosophiæ Naturalis Principia Mathematica. Proginoskes (talk) 16:59, 15 May 2008 (UTC)

I am afraid that geology as a terms is probably now used more in the sense of this article than the way you were taught. All words even in science are malleable. As long as we are consistent in the article it is OK IMHO. Oh and there is always the problem of lunar geology - if we take the original meaning of geology this is a contradiction in terms. (oh and the atmospheric science people at the University of Cambridge work in the Department of Applied Maths and Theoretical Physics, Chemistry department and Geography and not earth which shows how useful traditional definitions are these days) --NHSavage 16:19, 30 December 2005 (UTC)

I was always thought that geology studies the solid earth while others like hydrology, pedology, athmospherical sciences study the other spheres and everything is systematized in physical geography. The scientific terms are never right. The term geography comes from the greek words Earth and to describe, which is much older origin (first used by Erathostenes 2000 years ago) while the term geology was firstly used by Jean-André Deluc in the year 1778.GeoW 08:49, 14 April 2006 (UTC)

[edit] Earth System Science

I think this article needs some careful thought about the conection from interdisciplinary science to Earth system science. I doubt for example that many oceanographers consider the ocean in complete isolation from meteorology (winds play an important role in ocean currents for example) or hydrology (fresh water). In the past each discipline has tended to see these as external forcings but as the models and scientific understanding improves it becomes harder to ignore all the feedbacks. Climate models are central to this but many other fields are recognising it. I'll work on an improved draft but if anyone else has ideas let me know or make changes.--NHSavage 16:19, 30 December 2005 (UTC)

I have modified the structure somewhat to try and make things better but any feedback welcome.--NHSavage 22:40, 19 January 2006 (UTC)

[edit] Converging sub-domain terminology

• Biological oceanography
• Chemical oceanography
• Geological oceanography

RJBurkhart 14:42, 15 January 2006 (UTC)

[edit] What a mess

This article is faulty. Geophysics is not a subdiscipline of geology. Geomagnetism is a subdiscipline of geophysics, not geology. Mining is engineering, not a subdiscipline of geology. Do not confuse mining geology with mining. Physical geodesy is a subdiscipline of geodesy, not geology. Seismology is a subdiscipline of geophysics, not geology. I can see that the earlier versions of the article correctly categorized geology, geophysics and geodesy as separate earth sciences, which is how they should be kept. Geology is not a synonym for earth sciences (or geosciences). Any geologist or geophysicist can tell you that.

OK - how's it look now? Reshuffled a bit and called it solid Earth instead of geology, does that stomp on anyone's turf toes :-) To me it's all geology, but I'm just a bit biased. And - geology is interdisciplinary, moved mineralogy up and atmos sciences too. Vsmith 02:32, 17 January 2006 (UTC)

[edit] New user box and category of possibe interest

This user is a geoscientist or is specializing in geoscience.

Perhaps a WikiGeoProject could be organized sometime. I agree with the above unsigned comment, geophysics is another example of a geo-related article in need of serious attention. - Eagle^amn 05:56, 7 February 2006 (UTC)

[edit] Earth science footer

I've put together a template for the earth sciences. Please do the WP thing. Template:Earth science Cheers, Daniel Collins 22:50, 21 March 2006 (UTC).

[edit] Environmental science?

I was wondering why Oceanography is considered part of Earth science while Environmental science is not? Thank you. — RJH (talk) 15:09, 22 February 2007 (UTC)

[edit] Oceanography Project Proposal

I propose a new project on one of the earth system sciences, WikiProject Oceanography; is there any interest in working on this project? It's much needed but would also be an undertaking and require at least a handful of committed editors to make it last and work. Evolauxia 21:51, 5 June 2007 (UTC)

The project is proposed at Wikipedia:WikiProject Council/Proposals#Oceanography. Evolauxia 23:03, 8 June 2007 (UTC)

[edit] Earth's energy

In geology, plate tectonics, mountain ranges, volcanoes, and earthquakes are phenomena that can be explained in terms of energy transformations in the Earth's crust^[1]. Recent studies suggest that the Earth transforms about 6.18 x 10^-12 J/s (joules per second) per kilogram. Given the Earth's mass, the rate of energy transformations inside the Earth is about 37 x 10¹² J/s (37 terawatts). The heat escaping from inside the Earth is only about 0.02% of the amount of energy Earth receives from Sun in the form of sunlight, and radiates back into space in the form of infrared blackbody radiation (~1.74 x 10¹⁷ J/s = 174 petawatts).

From the study of neutrinos radiated from the Earth (see KamLAND), scientists have recently estimated that about 24 terawatts (65%) of this rate of energy transformation is due to radioactive decay (principally of potassium 40, thorium 232 and uranium 238), and the remaining 13 terawatts is from the continuous gravitational sorting of the core and mantle of the earth, energies left over from the formation of the Earth, about 4.57 billion years ago (this sorting represents continuing gravitational collapse of the Earth into the maximally compact object which is consistent with its composition-- a process which releases gravitational potential energy), and finally - from tidal flexing of Earth's interior and crust. The magnitude of all of these energy sources decline over time, and based on half-life alone, it has been estimated that the current radioactive energy of the planet represents less than 1% of that which was available at the time the planet was formed.

As a result, geological forces of continental accretion, subduction and sea floor spreading, account for 90% of the Earth's energy. The remaining 10% of geological tectonic energy comes through hotspots produced by mantle plumes, resulting in shield volcanoes like Hawaii, geyser activity like Yellowstone or flood basalts like Iceland.

Tectonic process are driven by heat from the Earth's interior. The process is a simple heat engine which works via the upward buoyancy-induced motion of hot, low density magma after expansion by heat. The processes metamorphically alter crustal rocks, and (more importantly from the energy view) during orogenies, lift them up into mountain ranges. The potential energy represented by the mountain range's weight and height thus represents heat from the core of the Earth which has been partly transformed into gravitational potential energy. This potential energy may be suddenly released in landslides or tsunamis. Similarly, the energy release which drives an earthquake represents stresses in rocks that are mechanical potential energy which has been similarly stored from tectonic processes. An earthquake thus ultimately represents kinetic energy which is being released from elastic potential energy in rocks, which in turn has been stored from heat energy released by radioactive decay and gravitational collapse in the Earth's interior.

The energy which is responsible for the geological processes of erosion and deposition is a result of the interaction of solar energy and gravity. An estimated 23% of the total insolation is used to drive the water cycle. When water vapour condenses to fall as rain, it dissolves small amounts of carbon dioxide, making a weak acid. This acid acting upon the metallic silicate minerals that form most rocks produces chemical weathering, removing the metals, and leading to the production of rocks and sand, carried by wind and water downslope through gravity to be deposited at the edge of continents in the sea. Physical weathering of rocks is produced by the expansion of ice crystals, left by water in the joint planes of rocks. A geologic cycle is continued when these eroded sediments are buried and later uplifted into mountains.

Similarly meteorological phenomena like wind, rain, hail, snow, lightning, tornadoes and hurricanes, are all a result of energy transformations brought about by solar energy on the planet Earth. It has been estimated that the average total solar incoming radiation (or insolation) is about 1350 watts per square meter incident to the summit of the atmosphere, at the equator at midday, a figure known as the solar constant. Although this amount varies a little each year, as a result of solar flares, prominences and the sunspot cycle. Some 34% of this is immediately reflected by the planetary albedo, as a result of clouds, snowfields, and even reflected light from water, rock or vegetation. As more energy is received in the tropics than is re-radiated, while more energy is radiated at the poles than is received, climatic homeostasis is only maintained by a transfer of energy from the tropics to the poles.

A volcano is the release of stored energy from below the surface of Earth originating in radioactive decay and gravitational sorting in the Earth's core and mantle of energies left over from its formation

This transfer of energy is what drives the winds and the ocean currents. Like biological processes, all meteorological processes involve transformation of energy from a concentrated form such as sunlight into a less concentrated form, such as far infrared radiation (i.e., heat radiation) at the much smaller characteristic temperatures that occur on Earth, and thus is diffused into many photons. However, energy may be temporarily locally stored during this process, and the sudden release of such stored sources is responsible for the dramatic processes mentioned above. For example, the kinetic energy of a snow-avalanche or hurricane is due to the sudden release of energy previously captured from solar radiations.

[edit] Distintiveness

I brought this up at Talk:Physical geography already: what is the distinction between Physical geography and Earth science? What warrants having two separate articles for what I always thought were synonyms?

Proginoskes (talk) 16:59, 15 May 2008 (UTC)

[edit] References

1. ^ Earth's Energy Budget