Intro to Climate Studies 2021-2022 (ENSC 220) Investigation 9A

Under the full impact of the PETM, ocean waters at those depths were approximately ______ saturated with CaCO3.

0%

The temperature during the PETM was ______°C warmer than the average temperature between 1960 and 1990.

14

"evaporation of ocean water and build-up of land ice during glacial climatic episodes results in ocean water enriched in ______."

18 O

the PETM as a temperature spike of several degrees Celsius that took place approximately ______ million years before present

56

The graph shows that during the period prior to and the period after the PETM, ocean waters at the two depths measured (4.8 km and 2.6 km) were approximately ______ saturated with CaCO3.

90%

Isotopic studies of benthic foraminifera fossils show that with the onset of PETM, about 55 Ma ago, there was a rapid ______ in the carbon isotope δ13 value. This is indicative of a large increase in the concentration of carbon dioxide and methane.

decrease

The oxygen isotope δ18 scale on the left increases downward, while the water temperature scale on the right increases upward. The middle graph shows a rapid decrease in oxygen isotope δ18 associated with a dramatic ______ in ocean water temperature of approximately 5°C.

increase

A challenge to determining climate sensitivity of the present day is that warming of the climate system ______ the buildup of greenhouse gases.

lags

The introductory paragraphs of the article note that the warming during the hyperthermals, including the PETM, was driven by large releases of ______ into the atmosphere.

methane and carbon dioxide

While the most widely-held theory for the carbon release is ______, there is a hotly debated paper concerning carbon input from ______ in the North Atlantic Ocean.

methane hydrates beneath the ocean floor or buried peat... volcanism

The rate of CO2 release during the hyperthermals was ______ the current atmospheric input.

much slower than

you can infer the oxygen isotope ratio (18 O:16 O) is a proxy for ______

temperature; glacial ice volume