with pollen & microfossilsindicating warm temps.
http://www.jsc.nasa.gov/images/eol/2003/owenslake.html
http://www.epa.gov/region09/air/owens/
http://www.owensvalleyhistory.com/ov_aqueduct1/page19.html
Amazon.com
The Himalayan glaciers feed seven of the great rivers of Asia (the Ganges, Indus, Brahmaputra, Salween, Mekong, Yangtze and Huang He) and supply fresh (melt) water runoff to 1/3 of the world’s population (~ 2 billion people).
http://assets.panda.org/downloads/glacierspaper.pdf
http://upload.wikimedia.org/wikipedia/commons/7/79/Himalayas.jpg
Global warming and freshwater supply in Asia…
Most people, if you describe a train of events to them, will tell you what the result would be. They can put those events together in their minds, and argue from them that something will come to pass. There are few people, however, who, if you told them a result, would be able to evolve from their own inner consciousness what the steps were which led up to that result. This power is what I mean when I talk of reasoning backwards, or analytically."
Sherlock Holmes: A Study in Scarlet, p. 57
Reconstructing climates is detective work.
http://www.research.noaa.gov/spotlite/archive/images/liquidgold_treering.jpg
https://www.e-education.psu.edu/gened/egee101/Examples/109_temperature_new.html
http://www.aims.gov.au/pages/research/darwin/dhwqmp/dhwq-200-03.html
Natural archives
http://banana.ifa.hawaii.edu/Weather/weather_station.gif
Price of rye in Germany vs. time expressed as an index. (Source: Lamb, 1995) http://www2.sunysuffolk.edu/mandias/lia/little_ice_age.html
Instrumental or historical archives
Sediment accumulates in “low spots”
http://iodp.tamu.edu/scienceops/maps/iodp_odp_dsdp.gif
http://www.usssp-iodp.org/Education/One_core.html
What are the sediment archives and what can they tell us?
Sediment Archive Proxy Indicator ofcoarse sand fraction of
biogenic material surface and deep water environmental
conditionslithic grains (ice-rafted debris) glacial activity on landvolcanic ash volcanic activity on land
Azolla: freshwater fern spore
http://www.water.sannet.ne.jp/nirei/palynology/zukan/spore01.jpg
pollen
http://www.immediart.com/catalog/images/big_images/NS_PN_B786630-Pollen_grain,_ESEM-SPL.jpg
Biological clues
Polar type
The dominant planktonic species, indicating
presence of cool surface waters
Non-polar types
T. G.
Developmental Steps in SST History
http://www.oum.ox.ac.uk/children/minerals/potplant.htm
Illite clay: physical weathering
Kaolinite clay: chemical weathering
http://www.ualberta.ca/~jwaldron/gallerypages/wavetide.html
Types physical and compositional evidence of past environments
http://www.koshland-science-museum.org/exhibitgcc/historical10.jsp
http://en.wikipedia.org/wiki/Ice_core
http://the-periodic-table.org/printable.gif
Determining age – isotopic decay “clocks”
Determining age – isotopic decay “clocks”
Determining age – isotopic decay “clocks”
http://www.geo.arizona.edu/Antevs/nats104/00lect11.html
Determining age – counting backwards (seasonal or annual layers)
Determining age – matching to known patterns
magnetic pole reversal pattern
http://www.geo.arizona.edu/palynology/geos462/pmabutlr.gif
Determining age – matching to known patterns
Glacial-interglacial cycles
Resolution of record - How detailed can you get?depends on sedimentation (accumulation) rate
http://www-odp.tamu.edu/publications/207_IR/chap_06/c6_f7.htm
Resolution of record - How detailed can you get?depends on how disturbed archive is
What archives you use depends on the timespan you are trying to reconstruct.
And – the more clues the better – aim for amultiproxy approach.