Magma

Magma is molten, liquid rock found under the surface of the Earth. Magma can also contain crystals, rock fragments and dissolved gases. The liquid part of magma is called the melt.

Earth is divided into three areas. The core is the superheated center, the mantle is the thick, middle layer, and the crust is the top layer on which we live. Magma originates in the lower part of the Earth’s crust and in the upper portion of the mantle. There, high temperatures and pressure cause some rocks to melt and form magma.

Magma is extremely hot—between 700 and 1,300 degrees Celsius (1,292 and 2,372 degrees Fahrenheit). When magma rises to the surface of the Earth through vents or during volcanic eruptions, it becomes lava. When lava stops flowing and cools, it hardens into igneous rock.

Magma can rise through breaks in the solid rocks of the crust and accumulate in large underground reservoirs called magma chambers. Heat from magma chambers can warm groundwater, which sometimes rises to the surface and forms hot springs.

Magma wells up through cracks in the seafloor and hardens into crust. Islands can be created this way. The Hawaiian Islands in the Pacific Ocean were formed by a series of underwater volcano eruptions whose lava hardened and eventually built up into the island chain.Magma is molten, liquid rock found under the surface of the Earth. Magma can also contain crystals, rock fragments and dissolved gases. The liquid part of magma is called the melt. Earth is divided into three areas. The core is the superheated center, the mantle is the thick, middle layer, and the crust is the top layer on which we live. Magma originates in the lower part of the Earth’s crust and in the upper portion of the mantle. There, high temperatures and pressure cause some rocks to melt and form magma. Magma is extremely hot—between 700 and 1,300 degrees Celsius (1,292 and 2,372 degrees Fahrenheit). When magma rises to the surface of the Earth through vents or during volcanic eruptions, it becomes lava. When lava stops flowing and cools, it hardens into igneous rock. Magma can rise through breaks in the solid rocks of the crust and accumulate in large underground reservoirs called magma chambers. Heat from magma chambers can warm groundwater, which sometimes rises to the surface and forms hot springs. Magma wells up through cracks in the seafloor and hardens into crust. Islands can be created this way. The Hawaiian Islands in the Pacific Ocean were formed by a series of underwater volcano eruptions whose lava hardened and eventually built up into the island chain.

Linnks and Sources:

National Geographic

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sharonstjoan's avatarEchoes in the Mist

The book, Underworld, the Mysterious Origins of Civilization, by Graham Hancock, has some fascinating chapters about Dwarka, in the state of Gujarat on the Kathiawar Peninsula by the Arabian Sea. There, a team of marine archaeologists, led by S. R. Rao, discovered a very large submerged site. Dr. Rao has led excavations of a vast number of important Indian sites, including many Indus Valley sites.

 

Graham Hancock and his wife, Santha, traveled there in 1992. Though British, he was not a stranger to India, having spent part of his childhood in Vellore, in Tamil Nadu. Santha’s family background is Tamil.

 

Hancock describes the Indian concept of cyclical time and the four yugas or four ages: the Krita Yuga, which is the “golden” age; the Treta Yuga, in which virtue has begun to decline and is less perfect than before; the Davapara Yuga, in which there is dishonesty…

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Stephen Vilaseca's avatarurbanculturalstudies

“Contemporary Cartographies. Drawing Thought” – CaixaForum Barcelona (July 25-October 28, 2012)

I find this to be a compelling image that speaks to the relationships between body, mind, and space. It forms part of an exhibition currently at CaixaForum in Barcelona. I have loosely translated from Spanish the following text found on CaixaForum’s website (http://obrasocial.lacaixa.es/nuestroscentros/caixaforumbarcelona/cartografiascontemporaneas_es.html):

The exhibition presents maps generated by artists of the twentieth and twenty-first century who interrogate and question systems of representation. They are cartographies of physical and mental spaces that generate new meanings and new insights about different types of spaces (heterotopias, utopias, invisible or virtual). Thus, we become aware of the prevalence of the simulacrum of reality, of our difficulties to represent the contemporary world and notions of ideology and power implicit in the act of representing.

“Contemporary Cartographies. Drawing thought” shows how artists have subverted cartographic language, from the map of the world of…

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urbanculturalstudies's avatarurbanculturalstudies

CFP-edited book on Marxism and Urban Culture

Submissions are invited for an edited book on Marxism and Urban Culture that has received initial interest from an international publisher known for their strength in Marxian-themed series and titles.

While all abstracts using a Marxian framework to approach culture in urban contexts are welcome, it is anticipated that submissions will conform to one of two subtypes reflecting the division of the book into

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