Week 4 Lecture

Question 1

What is the spreading rate hypothesis?

Answer 1

breakup of Pangea led to the dispersal of continents
increased subduction and of Mid-oceanic spreading ridges
therefore decrease in the CO2

Question 2

does the spreading rate hypothesis explain trends observed?

Answer 2

trend and the drops are well captured
The 80 Ma peak is not reproduced, and the
~40 Ma peak is underestimated

Question 3

What is the PETM?

Answer 3

Paleocene-Eocene Thermal Maximum

13-14 warmer than present day

Question 4

What is the EECO?

Answer 4

Early Eocene Climate Optimum

Question 5

What is the the mountain building hypothesis?

Answer 5

negative feedback loop that removes CO2

Question 6

What are the steps in the mountain building hypothesis?

Answer 6

sea floor spreading causes CO2 input
warm greenhouse climate
increased weathering
increased co2 removal
negative feedback loop

Question 7

What did the opening of the east west channel ?

Answer 7

It warmed the earth

Question 8

Why did the opening of the east west channel have its effect?

Answer 8

During the continental drift, the opening of the neo-Tethys took warm circum-equatorial currents in the continent interiors. The whole Earth warmed up

Question 9

What are the major CO2 inputs?

Answer 9

MOR & Subduction Zones

Plate Margins

Question 10

What are the major CO2 outputs?

Answer 10

Burial in Oceanic Basins
(Continental Breakup) and
Topographic Uplift (Orogenesis)

Question 11

How does weathering effect CO2?

Answer 11

It removes CO2