Attention Deficit Disorder Prosthetic Memory Program

Snowball Earth

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Snowball Earth - © Attention Deficit Disorder Prosthetic Memory Program

The Snowball Earth hypothesis proposes that during one or more of Earth’s icehouse climates, Earth’s surface became entirely or nearly entirely frozen, sometime earlier than 650 Mya (million years ago) during the Cryogenian period. Proponents of the hypothesis argue that it best explains sedimentary deposits generally regarded as of glacial origin at tropical palaeolatitudes and other enigmatic features in the geological record. Opponents of the hypothesis contest the implications of the geological evidence for global glaciation and the geophysical feasibility of an ice- or slush-covered ocean and emphasize the difficulty of escaping an all-frozen condition. A number of unanswered questions remain, including whether the Earth was a full snowball, or a “slushball” with a thin equatorial band of open (or seasonally open) water.

The snowball-Earth episodes are proposed to have occurred before the sudden radiation of multicellular bioforms known as the Cambrian explosion. The most recent snowball episode may have triggered the evolution of multicellularity. Another, much earlier and longer snowball episode, the Huronian glaciation, which would have occurred 2400 to 2100 Mya, may have been triggered by the first appearance of oxygen in the atmosphere, the “Great Oxygenation Event”.

Sea Shadow (IX-529) - © Attention Deficit Disorder Prosthetic Memory Program
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Sea Shadow (IX-529)
Zone Of Death - © Attention Deficit Disorder Prosthetic Memory Program
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Zone Of Death
Antikythera Mechanism - © Attention Deficit Disorder Prosthetic Memory Program
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Antikythera Mechanism
Out-of-place Artifact - © Attention Deficit Disorder Prosthetic Memory Program
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Out-of-place Artifact
Largest Hiking Boot - © Attention Deficit Disorder Prosthetic Memory Program
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Largest Hiking Boot
Chūken Hachikō - © Attention Deficit Disorder Prosthetic Memory Program
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Chūken Hachikō
Scaled Composites Model 351 Stratolaunch - © Attention Deficit Disorder Prosthetic Memory Program
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Scaled Composites Model 351 Stratolaunch
Cobalt Blue Tarantula - © Attention Deficit Disorder Prosthetic Memory Program
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Cobalt Blue Tarantula
Mimetic Hot Air Balloons - © Attention Deficit Disorder Prosthetic Memory Program
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Mimetic Hot Air Balloons
Atomic Gardening - © Attention Deficit Disorder Prosthetic Memory Program
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Atomic Gardening
Roundabout Public Art - © Attention Deficit Disorder Prosthetic Memory Program
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Roundabout Public Art
Polyphemus - © Attention Deficit Disorder Prosthetic Memory Program
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Polyphemus

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