What is Magma: Definition and 15 Discussions

Magma (from Ancient Greek μάγμα (mágma) meaning "thick unguent") is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and gas bubbles.Magma is produced by melting of the mantle or the crust at various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal-rich mush zones. During their storage in the crust, magma compositions may be modified by fractional crystallization, contamination with crustal melts, magma mixing, and degassing. Following their ascent through the crust, magmas may feed a volcano to be extruded as lava, or solidify underground to form an intrusion, such as a igneous dike or a sill.
While the study of magma has historically relied on observing magma in the form of lava flows, magma has been encountered in situ three times during geothermal drilling projects—twice in Iceland (see Use in energy production), and once in Hawaii.

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  1. BillTre

    Volcanologists want to put sensors directly into an Underground Magma Chamber

    This Science magazine news article discusses how a magma field was accidentally drilled into and how they plan to make a more permanent magma observatory.
  2. EnumaElish

    A sesimic image of the whole Earth

    Kiss the Mediterranean goodbye. Ditto the Red Sea and its wonderland of coral reefs and exotic sea life. And prepare for the day when San Francisco has a gritty new suburb: Los Angeles. Indeed, much of Southern California, including the Baja Peninsula, will eventually migrate up the west coast...
  3. A

    What is solidus and liquidus temperature of granite?

    My understanding is that because a rock is composed of variety of minerals, so it does not have fix melting point, rather there is a range below which whole rock is solid and above which whole rock is liquid. I want to know this liquidus and solidus temperature for granite rock based on pressure...
  4. A

    Processes in Convection cells / magma intrusion

    Yes this is a bit broader question but I want to know which processes play their role in movement of magma. If one wants to model magma movement through rocks, which processes should one not miss at all and which equations discuss these processes?. As a starter I can that we can use Navier...
  5. Astronuc

    Taupo, New Zealand - Magma chamber

    Molten rock accumulates in a magma chamber outside the North Island’s main volcanoes http://www.scientificamerican.com/article/zombie-volcano-slowly-grows-beneath-new-zealand/ Something for folks near Taupo to keep an eye on. Where's Taupo? https://en.wikipedia.org/wiki/Taupo...
  6. P

    Underground magma ocean could explain Io's 'misplaced' volcanoes

    Underground magma ocean could explain Io's 'misplaced' volcanoes Tides flowing in a subsurface ocean of molten rock, or magma, could explain why Jupiter's moon Io appears to have its volcanoes in the "wrong" place. New NASA research implies that oceans beneath the crusts of tidally stressed...
  7. @PinkGeology

    Why would hot fluid retain more % heat at lower flow rates?

    Homework Statement Hot magma (1500 K) is flowing into the Earth at rates of 0.05 meters/year, 0.5 meters per years and 1 meter per year. Although more total volume of magma will retain a temperature at or above 1150 K at higher rates of flow for any given time (say, at 1000 years), a higher...
  8. PinkGeologist

    Numerical modeling of hot magma

    Ok, I've built a numerical model to show the cooling of hot magma sills entered into the crust over time. The results show that the volume of the "hot" zone when the emplacement of a constant volume of hot sills is all done will vary as a matter of two things: the overall rate at which the magma...
  9. 1

    What is the GCD of A and B on a Union Magma?

    Homework Statement Consider the following magma, S is not empty; P(S) is the power set. (P(S), U) Now, let A and B be in P(S). What is the GCD of A and B? Homework Equations The Attempt at a Solution If I choose a common divisor of A and B under unions, call it X, I get...
  10. I

    Potential electricity production from water passed through Magma.

    Dear Physicists I am well aware that this question does not have all the necessary information on order to get an exact answer, but what I am hoping to find is some educated guesses backed by some math. Lets imagine a 50 MT Pot filled with magma that is 700 C hot. Let’s imagine a thin pipe...
  11. T

    Harnessing Underground Magma for Power: A New Idea?

    sooo, i was thinking, why don't we use the heat from underground magma channels to boil water and drive steam turbines, seems like a pretty stable way to make power. has anyone tried this before?
  12. L

    Explain Magma: Basaltic vs Rhyolitic Temperatures

    Can somone explain to me about Magmas which have different chemical compositions have different temperatures i.e basaltic magmas erupt at about 1200 °C whereas rhyolitic magmas erupt at about 700 °C. what is the difference in chemical composition between these two? also why can the composition...
  13. T

    Loss of heat from magma of Earth

    If the Earth's magma lost enough heat for it to solidify to a noticeable extent(permanent change, assuming irreversible), how would it affect its rotation about Earth's own axis and revolution around the Sun?
  14. C

    Solving x5 in Terms of x Using Magma

    if x is an integer, x1=6x2+8x+2 x2=6x21+8x1+2 x3=6x22+8x2+2 x4=6x23+8x3+2 x5=6x24+8x4+2 if i want to see x5 in terms of x, can it it done using magma? if so can somebody please give me the code? thanks.
  15. T

    Moduloid - Abelian Unital Magma

    Magma as the mathematical object may be too big to be dealt with. However I found the magma which is commutative and has the unit element has some interesting properties which might be applicable to algebra and topology. For details, please visit...