What is Paleoclimatology, why do we study it?
It the study of climate archives to help reconstrct information about earth’s climate history. We must study it because instrumental records only date back so far.
List five important climate archives. (and their sub catagories)
- Sediments (Marine & lacustrine)
- Ice (Sea & Terrestrial)
- Corals
- Trees
- Speleothems
Do climate archives give us direct information about the past climate?
No, they provide us with indirect information that we can then manipulate in order to approximate (proxies) past climate.
- Calibration is ?
- Reconstruction is?
- Calibration is aligning peaks and troughs in data sets.
- Reconstruction is allowing the data collected to span as far back as possible with relation to the calibration
List some indicators of climate change. (6)
- Global surface temperatures
- GHG conc.
- Sea level Change
- Ocean acidification
- Ice (Mass balance)
- Extreme events
Name two types of Terrestrial sediments and where they can be found
Loess and Eolian dust - found near glaciers
Affects of timescale on Sediments (deep ocean)
the longer the time scale, the closer to tectonic scale processes, less likely for old sediments to be preserved. (lower resolution the deeper one goes)
List 3 sources of Marine Sediments (give examples)
Physical (transport by water)
Chemical (erosions of parent rock)
Biological (crustations)
IODP is
Integrated Ocean Drilling Program
Paleoceanography is
The study of marine sediments for insights into past ocean and atmospheric climates
List the 6 types of lakes, Give brief description
- Tectonic lakes - result of tectonic movements
- Glacial lakes- result of melting
- Coastal Lagoons - near ocean, give sea level history
- Crater lakes -
atmospheric records - Landslide lakes - catchment sensitive
- Fluvial - highly dynamic
Varves are
The annual lamination observed in lake sediments
What are Ice cores useful for? (Use great detail)
- Determining the past GHG concentrations (CO2, CH4) in the atmosphere due to fluid trapping. direct measurement. -O18 can also help us uncover temperature history.
- Annual Resolution
Two locations for collecting good ice cores
Greenland, Antarctica
Tree Rings offer what to paleoclimatologists?
They offer yearly resolution as well as strong indications of drought or warm years (depending on location)
What is Dendrochronology
study of tree cores
How far back can tree rings give us information on?
500 - 1000 years
What is the most important paleoclimate archive?
Ice cores, O18, liquid inclusion, etc.
Define speleothems, where can they be found?
mineral deposits formed underground, stalagmites, stalagctites, found globally
Benefits of speleothems? list 4
- long time interval (1Myrs)
- Precisely dated (100 yrs precision)
- well conserved
- found all over the globe
How do you test speleothems??
monitor preciptation on land,
collect drip water,
break and sample. fluid inclusion water.
Issues with corals climate archives?
Often gaps, dating uncertainty
List the 6 main Paleoclimate Archives
- Corals
- Speleothems
- Tree rings
- Ice cores
- Lake / marine Sediments
- Historical documents
List the methods of paleoclimate dating (5)
- counting annual lamination
- Old Radiometric Dating
- correlative Dating (tephrochronology)
- Radiocarbon dating
- pb210 and cs137 dating
