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22 votes
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Can living where (rare) earth magnetic ore is abundant provide any protection from cosmic radiation?

Absolutely not. First of all, "rare earth magnet ore", meaning the ores of metals like neodymium (Nd) and samarium (Sm), is not magnetic at all. It only becomes a magnet once you make a ...
Gimelist's user avatar
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11 votes

Can living where (rare) earth magnetic ore is abundant provide any protection from cosmic radiation?

No. Cosmic radiation are high-energy particles that create particle showers high up in the terrestrial atmosphere. Those particle shower are heavily beamed downwards, and although in principle some ...
AtmosphericPrisonEscape's user avatar
8 votes
Accepted

Does Magnetic Deviation depend on altitude?

Technically yes, but practically, usually no. The magnetic field varies in three dimensions and the variations are not parallel to the Earth's surface. However, horizontal distances varies usually ...
user2821's user avatar
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5 votes

Why do (some) silicic bodies behave effusively instead behaving explosively as in common?

To complete Gimelist's answer: many silicic domes and flows lie right on top of a tephra layer with the same age and composition. See for instance this classic paper of Fink (1980) about Little Glass ...
Jean-Marie Prival's user avatar
5 votes
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Why do (some) silicic bodies behave effusively instead behaving explosively as in common?

Explosive volcanic events happen mostly because of saturation in gases, and increase in pressure above the strength of the top of the magma chamber. As the magma decompresses or cools, H2O (mostly), ...
Gimelist's user avatar
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4 votes

Why is ignimbrite associated with felsic magmas?

Felsic magmas contain much more silica (SiO2) than mafic magmas (almost by definition). The excess silica chains cause the magma to be much more viscous and therefore more prone to explosive eruptions ...
Antonio's user avatar
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4 votes
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What is the difference between subvolcanic rocks and plutonic rocks?

Main difference between a subvolcanic verses a plutonic is depth at which the rock solidified at from its molten state. Plutonic implies a depth greater than subvolcanic by definition but I am sure ...
Earth Science Expatriate's user avatar
4 votes
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Relative dating of intrusion

It does seem like it's impossible to know unless you have additional information. However, I think there is a hint in there. See this white halo around the intrusion? My guess (and I could be wrong ...
Gimelist's user avatar
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4 votes
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What is the difference between a depleted mantle, and a fertile or enriched mantle?

Basically, a fertile mantle is a portion of mantle that has not experienced any melting. On the other hand, a depleted mantle has experienced partial melting, and subsequent extraction of this melt. ...
Jean-Marie Prival's user avatar
4 votes

How does one get a steep-sided stratovolcano with extremely fluid, low-viscosity lava?

Volcano Café just published a series of articles about Nyiragongo, with one part answering this very question: "Steep slopes despite very fluid lavas. How Nyiragongo got it shape". (It is ...
Jean-Marie Prival's user avatar
3 votes
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Is there any diferrence between arc magmatism and post-collisional extension magmatism?

The answer is yes, but the differences, if you mean tangible differences in composition and nature of the melt and not just primary melt source, are minor and technical. This is a complex subject but ...
Josiah's user avatar
  • 143
3 votes

How do you determine if basalt originates from a mid-oceanic ridge or from a continental flow?

The basalt from ocean floors is called a MORB (mid-ocean ridge basalt) while the basalt emplaced in a continental setting is usually an alkali basalt. They can be easily distinguished by their ...
Jean-Marie Prival's user avatar
3 votes

Why the "Mission to Earth’s core" proposal suggests using liquid iron instead of lead?

I've already commented on this before here. This will not work regardless of whether this is iron or lead or anything else. The fact that it was published in Nature does not mean it is true, always ...
Gimelist's user avatar
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3 votes

Melting basalt on the lunar surface - what would the resulting material be like?

Melting lunar dust of basaltic composition will result (unsurprisingly) in basalt lava. There might be some volatile loss - if for some reason the basalt had some H2O or CO2 trapped in the solid you ...
Gimelist's user avatar
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2 votes

Why does the loss of water from a felsic magma encourage crystallisation?

This answer is based on Winter's presentation for his textbook. Look up chapter 7 on his website, and start at slide 39. First let's go through some of your statements: Felsic magmas crystallise ...
Gimelist's user avatar
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2 votes

Cooling time of basalt flows?

Of course there is, and in not that complex. Is called the heat equation, and is a type of diffusion equation that can be easily solved numerically or analytically in some simple geometries. If you ...
Camilo Rada's user avatar
  • 17.7k
2 votes

Can living where (rare) earth magnetic ore is abundant provide any protection from cosmic radiation?

Magnetite is a type of iron ore and does not significantly affect the Earth's magnetic field. It would not protect you from cosmic radiation. However, cosmic radiation is more intense high in the ...
Michael Walsby's user avatar
2 votes
Accepted

Heating and cooling a non-magnetic iron ore causes it to become magnetic?

What's happening is called induced magnetism, detailed in a variety of places, including this paper by Kostadinova-Avramova and Kovacheva in Geophysical Journal International: It is well ...
jeffronicus's user avatar
  • 3,487
2 votes

Can living where (rare) earth magnetic ore is abundant provide any protection from cosmic radiation?

The magnetic field stops the charged particles mostly by trapping them along their fields lines (globally parallel to the ground at most latitudes, plunging to the ground near the poles (therefore ...
franck's user avatar
  • 21
2 votes

Can living where (rare) earth magnetic ore is abundant provide any protection from cosmic radiation?

Although the other answers have correctly pointed out that this isn't a relevant thing on Earth, it should be mentioned that such an effect does occur on the Moon: it is the likely cause for the Lunar ...
leftaroundabout's user avatar
2 votes
Accepted

How do you understand the occurence of an alteration zone?

That is a great question and one that might not be simple to answer in a short response. For more detailed information you can look to the work of Drs. Marco Einaudi, John Dilles, Mark Barton (...
Josiah's user avatar
  • 143
1 vote

How does one get a steep-sided stratovolcano with extremely fluid, low-viscosity lava?

Ol Doinyo Lengai is a carbonatite volcano (the only active one known today) that produces relatively cool lava that quickly solidifies. The large lava lake in Mount Nyiragongo would, I suspect, cool ...
verisimilidude's user avatar
1 vote

What are the properties of the back arc extension related volcanic rocks?

Back arc basin lavas are basaltic and similar to the magma from mid ocean ridges, except that the magma from back arc basins is about four times as rich in magmatic water, which is typically 1.5 ...
Michael Walsby's user avatar
1 vote

Which equations describe complete (or near complete) behaviour of magma moving through rocks?

From McKenzie's original 1984 paper and from Spiegelman & McKenzie (1987) paper the equations that govern the conservation of momentum and mass of a low-viscosity fluid melt (magma) in a ...
arkaia's user avatar
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