What was the weather and climate like in prehistoric times?
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This table is a reference tool for rapidly locating Wikipedia articles on Historic and Prehistoric climate indicators of all types. Method Type Basis Interpret Instruments Back To Varve Analysis Geological Annual bands of seasonally differing particle size in glacial lake deposits Samples carry Proxies. Thicker bands = warmer, wetter weather Visual and Microscope ca 13,000 yrs BP Dendrochronology Biological Annual bands of seasonally differing woody growth tissue in trees Thicker bands = warmer, wetter weather Visual and Microscope ca 10,000 yrs BP Ice cores Geological Annual (or periodic) layers of differing ice crystals in glaciers and ice caps Samples carry Proxies. Thicker bands = colder, snowier weather Chemical and Mass Spectrometer ca 800,000 yrs BP Speleothems Geological Layers of seasonally differing stalagmite/stalactite deposits in limestone caves Samples carry Proxies. Thicker bands = warmer, wetter surface weather Visual and Microscope ca 500,000 yrs BP Sun Spots Astronomical Number of spots visible on the surface of the Sun over various periods More spots = warmer weather cycles Visual and Telescope 1700 AD Oxygen Isotope Analysis, see marine isotope stage Geochemical Climate Proxy Ratio of Oxygen-18 to Oxygen-16 in calcite from deep sea sediment, and coral cores More Oxygen-18 = colder climatic periods Mass Spectrometer ca 542,000,000 yrs BP Beryllium-10 Analysis Geochemical Climate Proxy Ratio of Beryllium-10 to daughter isotopes in dust from ice cores Produced in atmosphere by cosmic rays and absorbed into the hydrologic cycle. Level of Beryllium-10 has been shown to closely match recent solar activity measured by sun spots Mass Spectrometer ca 80,000 yrs BP To Add: Alkenone analysis TEX-86 analysis Nile river flood levels Trace mineral ratios in deltaic sediment Wildlife distribution Pollen analysis Historic storm-related sinkings Sea temperature and atmospheric pressure (ENSO) Scientific meteorological measurements (since 1800's) air temperature air pressure wind speed and direction Ocean currents and marine productivity Flooding and drought observations on land Volcanic activity elevated charcoal in lake sediments sand dune activation records eolian (wind-borne) sediment deposition
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