Question

please choose correct answer and explain

1) If the Deuterium abundance in an ice core is relatively high, we know that

A) The air was cold when the snow fell.

B) The global ice volume is high

C) The global ice volume is low

D) The air was warm when the snow fell.

2) If the oxygen 18 in an ocean sediment core is high, we know that,

A) The sea surface temperature was low.

B) The land ice volume was high when the sediment was deposited..

C) The land ice volume was low when the sediment was deposited..

D) The sea surface temperature was high.

3) When the obliquity is high, ice ages are,

A) Less likely.

B) More likely.

C) About the same.

D) None of these answers.

4) When the precession parameter, eccentricity times sine of longitude of perihelion, is large, summertime Northern Hemisphere high latitude insolation is,

A) less

B) more

5) During the Pleistocene Ice Ages, atmospheric CO₂ was

A) about 275 ppm

B)about 180 ppm

6) About 8,000 years ago hippopotami roamed the region that is now the Sahara desert because,

A)CO2 was lower then, so the atmospheric coolling drove convection.

B)The precession parameter brought more insolation to the Northern Hemisphere Summer.

C) It rained more in the Sahara during the cool period at the end of the past ice age maximum.

7) Pound for pound methane is a more effective greenhouse gas than CO₂.

A) true

B)false

Answer 1

Answer to Q 1: d) The air was warm when the snow fell (high temperature forced heavier Deuterium to go into vapor phase which in normal temperatures is enriched in the sea water instead of post vapor condensation like snow or ice packs which is normally deficit in Heavier stable isotopes. In short more energy is required for heavier isotopes to go into vapor phase which is provided by warm earth)  

Answer to Q 2: b) The land ice volume was high when the sediment was deposited (when we have more land ice it means that we have more heavier isotopes of oxygen in seawater as the bulk of lighter oxygen molecules are evaporated frequently and therefore locked in the ice sheets)

Answer to Q 3: a) Less likely (high obliquity means more insolation in the higher latitudes which melts more of the ice present in the polar regions which causes decrease in the amount of area covered by ice and a uniformity of temperature between the equatorial and polar regions while as if we have more contrastive differences in temperature between the equatorial and polar regions, the chances of an ice age get higher)

Answer to Q 4: B) more

Answer to Q 5: B) About 180 ppm (during ice ages the amount of CO_² is observed to have plunged)

Answer to Q 6: C) It rained more in the Sahara during the cool period at the end of the past ice age maximum

Answer to Q 7: A) True