Which of the following accurately describes 18O/16O ratios of the ...

[cdr_15]

Which of the following accurately describes 18O/16O ratios of the world's oceans?
 
  A) Neither the 16O or 18O isotopes are common in water, so when either is present, it shows a disequilibrium in normal climatic conditions.
  B) The 16O/18O ratio is low during colder temperatures because temperatures are too low for evaporation to be effective and both isotopes remain in the ocean.
  C) Because 18O evaporates more readily than 16O, the oceans have a higher relative abundance of 16O during warm periods and a more balanced ratio when evaporation is less.
  D) During periods of colder temperature 16O is locked up in snow and ice and the oceans have a higher preponderance of 18O; during warmer periods the isotope ratio of 16O to 18Ois higher.
  E) The higher the ratio of oceanic 16O to 18O, the colder the temperatures because the 18O will have been mostly evaporated from ocean waters.

Question 2

Katabatic winds are
 
  A) another name for mountain-valley breezes.
  B) localized winds associated with sea-breezes.
  C) regional-scale, gravity-driven winds that bring high density air downslope.
  D) usually weaker than local winds, but significant due to the area they cover.
  E) uncommon in areas with extremely cold conditions, such as Greenland or Antarctica.

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Answer to Question 1

D

Answer to Question 2

C

[cdr_15]

Excellent

[Joy Chen]

Gracias!