Magma is a high-temperature, silicate-dominated molten or partially molten substance generated within Earth’s crust and mantle by decompression melting, flux melting, or heat transfer. It consists of a continuous liquid phase containing dissolved volatiles (e.g., H₂O, CO₂, SO₂), suspended crystals, and sometimes entrained xenoliths. Its physicochemical properties—temperature, viscosity, density, and volatile content—are governed by bulk composition (mafic to felsic), pressure, and crystallinity. Magma behaves as a complex multiphase fluid, undergoing differentiation by fractional crystallization, assimilation, and mixing, and on ascent can evolve into eruptible magma that degasses and solidifies to form igneous rocks.
The magma reservoir of the largest volcanic eruption of the Holocene is refilling. This Kobe University insight on the Kikai caldera in Japan allows us to understand giant caldera volcanoes like Yellowstone or Toba more generally ...
Earth Sciences
Mar 27, 2026
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About 56 million years ago, Europe and North America began pulling apart to form what became the ever-expanding North Atlantic Ocean. Vast amounts of molten rock from Earth's mantle reached the ocean floor as the crust stretched ...
Earth Sciences
Feb 18, 2026
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61
What appears to be a single volcanic eruption is often the result of complex processes operating deep beneath the surface, where magma moves, evolves, and changes over long periods of time. To fully understand how volcanoes ...
Planetary Sciences
Feb 11, 2026
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46
Scientists have long known that Earth's core is mostly made of iron, but the density is not high enough for it to be pure iron, meaning lighter elements exist in the core, as well. In particular, it's suspected to be a major ...
Deep beneath the surface of distant exoplanets known as super-Earths, oceans of molten rock may be doing something extraordinary: powering magnetic fields strong enough to shield entire planets from dangerous cosmic radiation ...
Astrobiology
Jan 15, 2026
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107
The mid-ocean ridge runs through the oceans like a suture. Where Earth's plates move apart, new oceanic crust is continuously formed. This is often accompanied by magmatism and hydrothermal activity. Seawater seeps into the ...
Earth Sciences
Jan 6, 2026
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33
A Carnegie-led team of astronomers detected the strongest evidence yet of an atmosphere around a rocky planet beyond our solar system. Their work, published in The Astrophysical Journal Letters, used NASA's JWST to reveal ...
Astronomy
Dec 28, 2025
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128
In astronomy, there is a concept called "degeneracy." It has nothing to do with delinquent people, but instead is used to describe data that could be interpreted multiple ways. In some cases, that interpretation is translated ...
Astrobiology
Dec 17, 2025
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55
Some 4.6 billion years ago, Earth was nothing like the gentle blue planet we know today. Frequent and violent celestial impacts churned its surface and interior into a seething ocean of magma—an environment so extreme that ...
Earth Sciences
Dec 11, 2025
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97
The explosiveness of a volcanic eruption depends on how many gas bubbles form in the magma—and when. Until now, it was thought that gas bubbles were formed primarily when the ambient pressure dropped while the magma was rising.
Earth Sciences
Nov 21, 2025
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