Paleoceanography II: Quaternary Oceans & Climate

Flashcards covering key vocabulary and concepts from a paleoceanography lecture on Quaternary Oceans & Climate.

Paleoceanography

The study of the physical, chemical, and biological states of past oceans.

Sediment Proxy

Measurable properties of an archive used to reconstruct past ocean environments.

Quaternary Period

The period that began 2.58 million years ago and contains the present-day glacial-interglacial climate regime.

Glacial-Interglacial Climate Cycles

Climate cycles characterized by alternating cool (glacial) and warm (interglacial) periods.

Foraminifera Test

External shell of foraminifera, composed of calcium carbonate (CaCO3).

Planktonic Foraminifera

Foraminifera that live in the upper ocean.

Benthic Foraminifera

Foraminifera that live on (epifaunal) or in (infaunal) seafloor sediments.

18O/16O Ratio

Relative amount of 18O to 16O oxygen atoms, which varies in seawater with climate changes.

Isotope Fractionation

Partitioning of heavy and light isotopes between two coexisting phases during biogeochemical reactions.

Ice Volume Effect

Effect where ocean water has higher 18O/16O during glacials and lower 18O/16O during interglacials due to ice sheet formation and melting.

Temperature Effect (Foraminifera)

Effect where foraminifera preferentially take up ‘heavy’ 18O over ‘light’ 16O from seawater during growth, with larger proportions in colder water.

Milankovitch Cycles

Cyclic variations in eccentricity, tilt, and precession of Earth’s axis that influence solar radiation and climate cycles.