What is Snowball Earth?
Q: What is Snowball Earth?
A: Snowball Earth or Icehouse Earth refers to times when the Earth's surface was nearly or entirely frozen.
Q: Is the occurrence of Snowball Earth still controversial?
A: Yes, the occurrence of Snowball (or Slushball) Earths is still controversial.
Q: When did widespread glaciation occur, according to the text?
A: According to the text, it is probable that widespread glaciation occurred in periods of the Proterozoic.
Q: What is debatable about the occurrence of Snowball Earths?
A: What is debatable is how widespread those glaciations were.
Q: What do proponents claim the Snowball Earth theory explains?
A: Proponents claim the theory explains sedimentary deposits of glacial origin at tropical latitudes and other strange features of the geological record.
Q: What do opponents of the Snowball Earth theory doubt?
A: Opponents do not draw the same inferences from the geological evidence, and doubt the geophysical feasibility of an entirely ice or slush-covered ocean.
Q: What is the Proterozoic?
A: The Proterozoic is a geological eon that occurred between 2.5 billion and 541 million years ago.
