STUDYING PAST CLIMATES. STUDYING CLIMATE IN THE PAST Paleoclimatologists study past climates They...
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Transcript of STUDYING PAST CLIMATES. STUDYING CLIMATE IN THE PAST Paleoclimatologists study past climates They...
STUDYIN
G PAST
CLIMATE
S
STUDYING CLIMATE IN THE PASTPaleoclimatologists study past climates
They use Proxy records; which are stores of information in tree rings, ice cores and fossils that can be measured to give clues to what the climate was like in the past
ICE CORESIce in Greenland and Antarctica contains air
bubbles that have been trapped for thousands of centuries
Scientists drill deep into the ice and extract long cylinders of ice
The ice at the top of the ice core is recent and the bottom ice can be up to 800 000 years old
ICE CORESScientist cut ice cores into very thin
slices and test the air bubbles in each slice for various gases
This measures the amount of carbon dioxide, methane and nitrous oxide that was in the air when the bubble formed
Ice cores have shown scientists that the concentration of these greenhouse gases has changed dramatically over Earth’s history
ICE CORESScientists can also obtain information about the
earth’s temperature, precipitation and volcanic eruptions through preserved layers of dust in an ice core
Ice cores tell scientists that the earth’s climate has gone through many changes in climate (including warmer and colder periods)
TREE RINGS When a tree grows, it creates one growth ring per
year
The rings are the thickest during the years of good growing conditions
Some trees live for thousands of years and scientists can assemble clues from living and dead trees about the climate during that time
CORAL REEFSLike trees, coral reefs add layers of growth each
season
Scientists drill cylinders of coral and study their layers
Information from coral layers help determine the temperature of the surface ocean water when each layer was growing
ROCK, CAVES AND OCEAN SEDIMENTLayers of soil and rock build up on the earth over
time and each layer gives clues, such as plant or fossils to the climate at that time
Sediment cores from the ocean floor contain clues that provide data about past climates
SUMMARYProxy records are indirect records of
past climates contained in natural materials
Analyzing air bubbles in ice cores provides data on greenhouse gases temperature from the past
Analyzing the growth rings on ancient trees and coral provides data on temperature and precipitation from the past