Discovering Past Climates 9.1

Paleoclimatology paleoclimatologists study past climate weather records only go back a few hundred years; to look at older data, special tools are used… Image from: http://oncirculation.com/2013/04/11/what-is-paleoclimatology/ Cool website…this page explains what paleoclimatology does.

Tree Rings dark wood in summer, light wood in spring thin rings in dry & hot conditons; thick rings in wet & cool conditions can show evidence of floods, droughts, insect attacks, lightning strikes, etc. Image from: http://yossipels.typepad.com/.a/6a0128771d526b970c0134851c48ed970c-popup

Megadrought Image from: http://www.kpbs.org/news/2013/jul/01/global-warming-aggravating-el-nino/ Narrow rings from 1560’s-1590’s indicate megadrought

Hurricanes Strengthening? Image from: http://www.kpbs.org/news/2013/jul/01/global-warming-aggravating-el-nino/

Ice Cores examining layers of snow & ice that can date back to 800 000 years ago Have a look at this video about ice cores taken in the British Antarctic Survey Video link: https://www.youtube.com/watch?v=VjTsj-fi-p0 Images from Greenland drilling: http://earthobservatory.nasa.gov/Features/Paleoclimatology_IceCores/

What is in the ice? Type of particles give clues about events that happened as well as vegetation Physical characteristics of the ice indicate temperature & humidity conditions when the ice was formed Composition of trapped air bubbles show atmospheric conditions when ice was formed Image from: https://en.wikipedia.org/wiki/Ice_core

Composition of Ice concentrations of isotopes (oxygen-16 and oxygen-18) in water indicate temperature at time of ice formation more 18O indicates higher temperatures Image from: http://www.antarcticglaciers.org/glaciers-and-climate/ice-cores/ice-core-basics/

Sedimentary Rock formed by yearly deposits of rock fragments…accumulate in thick layers on ocean floors & become compressed and hardened over many years Image from: https://en.wikibooks.org/wiki/High_School_Earth_Science/Sedimentary_Rocks

Core Samples pollen can indicate vegetation & climate composition of shells (isotopes) can determine temperature fossils determine which living organisms were present & this indicates specific climate conditions Image from: http://www.nasa.gov/topics/earth/features/samples20120617.html

Varves annual sedimentary deposits in glacial lakes light (summer) & dark (winter) layers Image from: http://eos.tufts.edu/varves/votw_details.asp?vid=25

Final Words… NOAA Paleoclimatology Data page…if you’re interested! video of a NOAA paleoclimatologist, explaining what kinds of data can be collected (including coral samples) Link: https://www.ncdc.noaa.gov/data-access/paleoclimatology-data Video link: https://www.youtube.com/watch?v=G8t5VX8JKhI