Geo 401 Exam 1 2023 with 100% correct answers

What characteristics would the ideal paleoclimate proxy have? - correct answer -A long term continuous quantitative record of key climate variables at all time scales over as wide a spatial range as possible. It never happens this way. If it grows millions of years, seasonal change, or quantitiative. Which of the following is not likely to be a useful paleoclimate proxy? - correct answer -you need something that has the ability for the need for age control. So look for what is telling you about how climate works and whats telling me about things like tectonic. Understand how radiocarbon forms and moves through the earths system. - correct answer -To form radiocarbon cosmic rays interact with Nitrogen in the upper atmosphere. 14N +n = 14C+p 14C quickly oxidizes to become CO2. 14CO2 then mixes with the rest of the atmosphere in months. The 14CO2 is exchanged at the oceans' surface. It mixes more slowly through the ocean on average of 400 years, but can take as long as 1000 or so. It varies due to vertical mixing in thermohaline and upwelling. The earth's magnetic field protects us from cosmic rays. The Magnetic field changes though time . Thus 14C is generated at different rates over time. Why do paleo climatologists measure clumped isotopes? - correct answer -Afinity for heavy isotopes to bind to each other. C and O inversely proportional to temperatures w/o knowledge of water chemistry What are the "clumped" isotopes? - correct answer - Where and why does S18O value of water to deviate most from typical ocean values? - correct answer -ocean =baseline (most water on earth day) heavier than baseline =evaporated lighter isotopes from water/sample. seawater=0=isotopic baseline. lighter than baseline=evaporated product. When ice sheets are large formed from precip. ocean favors heavy isotope. At what depths do foraminifera live? - correct answer -Most are marine and a majority of which live on or within the seafloor sediment while a smaller variety float in the water column at various depths aka all depths.