Chapter 12 Bao Mario Ariel amp Keiyro 121 Project CLIMAP CLIMAP Climate Mapping and Predictions Project began in early 1970s First map of iceage Earth released 1976 121 First CLIMAP Map ID: 549114
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Slide1
Last Glacial Maximum
Chapter 12
Bao, Mario, Ariel, & KeiyroSlide2
12-1 Project CLIMAP
CLIMAP (Climate Mapping and Predictions) Project began in early 1970s
First map of ice-age Earth released 1976Slide3
12-1 First CLIMAP MapSlide4
12-1 Project CLIMAP
Major Ice Sheets….
-Laurentide ice sheet
-Cordilleran ice sheet
-Scandinavian ice sheet
-Barents ice sheetSlide5
12-2 How Large Were the Ice Sheets?
CLIMAP reconstruction highly controversial due to:
1. The extent that ice reached
2. Ice centered on marine ice sheets
3. Thickness and height of ice sheetsSlide6
12-3 Glacial Dirt
Glacial outwash: sediment deposits from glacial meltwaterSlide7
12-3 Wind
Wind reworks and carry deposits
-Deposits can be
worldwide
-Na
+
and Cl
-
ions
(salt)Slide8
12-4 COHMAP
COHMAP (Cooperative Holocene Mapping Project) began in 1980s
Combined data-model approach to examine the last glacial maximum and subsequent changes to interglacial conditions.Slide9
12-4 COHMAP Approach
1. Assemble records of changing conditions that drive climate
-Over last 21,000 years
2. Ran model simulations of climate
3. Climate data produced was tested against climate reconstructionsSlide10
12-5 Pollen: A Climate Indicator
Precipitation and temperature determine vegetation growth
Pollen is carried by wind, water, insects
-Settles into mud and preservedSlide11
12-5 Pollen in a Lake Core
-Spruce pollen
-Oak pollen
-Prairie pollenSlide12
12-6 Distribution of Spruce PollenSlide13
12-6 Biome Models
A model that simulates the vegetation that can exist in a regionSlide14Slide15
12-7 Glacial Ice Sheets
Ice sheets affected atmospheric flow
Massive, icy plateaus blocked/redirected the flow of airSlide16
12-8 Northern Ice Sheets
Most dramatic climate changes experienced by regions closest to ice sheetsSlide17
12-8 Changes in North America
Lakes once occupied deserts in SW U.S
Pacific NW was colder and drier
Climate due to jet stream’s influenceSlide18
Glacial LakesSlide19
12-8 Changes in Eurasia
Climate was far harsher and colder
Less trees and vegetationSlide20
European SteppeSlide21
12-8 Europe ComparisonSlide22
12-8 Permafrost
Permafrost: permanently frozen soil and rocks due to the cold
Evidence of permafrost in AsiaSlide23
12-9 Away from the Northern Sheets
Climate changes less dramatic
More affected by CO
2
and methane gasSlide24
ITCZ BiomassSlide25
12-9 Glacial Tropics
Oceans were 1°-2°C cooler
-Based off plankton fossils
Tropics too far away from ice sheets to be affected
-What caused cooling in the tropics?Slide26
12-10 Small Tropical Cooling
CLIMAP reconstruction based on planktic fauna/flora in oceans
Evidence shows ocean temperatures cooled by an average of 1.5°CSlide27
12-10 Alkenones
Alkenones: organic molecules in plant plankton shells
Used in temperature reconstructionsSlide28
12-11 Large Tropical Cooling
The atmosphere cools 6.5°C for every kilometer
4°-6°C cooling shown from drop in ice line of tropical mountainsSlide29
12-11 Large Tropical Cooling Slide30
12-12 Tropical Cooling
CLIMAP estimated tropical cooling to be small
and
Critics estimated tropical cooling to be large
Which side was right?Slide31
12-12 Medium-Small Cooling
Errors of CLIMAP
-Dissolved CaCO3
samples
-Latitude and Plankton
adaptabilitySlide32
12-12 Medium-Small Cooling
Discrepancies between land and ocean temperature changes
-Lowering of sea level
-Greater land response to climate forcingSlide33
12-12 Medium-Small Cooling
Temperature drop estimated to be 3°C
Models capture effects of greenhouse gases
-Useful in forecasting future climate changes