Knowra Paleoceanography Paleoceanography Paleoceanography reconstructs past ocean conditions, circulation, and ecosystems from geological, chemical, and biological evidence preserved in marine sediments and other archives.
Marine sediment core : A cylindrical sample of seafloor sediment collected to study the sequence of deposits through time. Layered cores preserve changing ocean conditions across thousands to millions of years.
Foraminifera : Single-celled marine protists, many of which build shells that become microfossils. Their shells preserve chemical signals, while species composition tracks habitat and water masses.
Paleoclimatology : The study of past climates using natural records and evidence. Ocean archives supply long climate records that complement evidence from land and ice.
Paleocene–Eocene Thermal Maximum : A rapid global warming event about 56 million years ago, marked by a large carbon-isotope excursion. Marine sediments record its carbon release, warming, ocean acidification, and deep-sea ecosystem disruption.
Proxy calibration : The process of relating a proxy measurement to the environmental variable it represents. Calibration determines how reliably sediment signals quantify ancient temperatures, chemistry, or circulation.
Microfossil : The preserved remains of microscopic organisms, including plankton and foraminifera. Changes in species and abundance reveal past water masses and marine ecosystems.
Alkenone : A long-chain organic molecule produced by certain marine algae and preserved in sediments. Its unsaturation varies with growth temperature, providing a sea-surface temperature proxy.
Paleocirculation : The reconstruction of past patterns of ocean circulation. Sediment and isotope records trace changes in currents and deep-water formation.
Younger Dryas : A return to near-glacial conditions in the North Atlantic region from about 12,900 to 11,700 years ago. Marine records document abrupt regional cooling and changes in ocean circulation during this interval.
Chronology (geology) : The ordering and dating of geological events and records. Age uncertainties can obscure whether ocean changes preceded, followed, or coincided with climate events.
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