CLIMATE CHANGE FINAL

What does paleoclimate look at?

Looking at climate shifts on a global level

With CO2, we have reached ____ ppm and the cap is _____ ppm

425; 550

how many notable shifts in climate change have there been in the past 2,000 years and what were they?

two, medieval warm period and the little ice age

During the medieval warm period, an increase of ____ degrees was seen

0.3

During the medieval warm period, ______ shipping had exploded

global

what group of people reached greenland during the medieval warm period?

the vikings

the medieval warm period is known as a ________ hemisphere event

northern

true or false: we do not know what caused the medieval warming period

true

During the little ice age, a decrease of ___ degrees happened

-0.5

the time period of the little ice age is

1550 CE to 1850 CE

What are the main two records for the little ice age?

farmers and art

What caused the little ice age?

The Maunder minimum and high amount of volcanic eruption

What is the Maunder minimum?

The time of extremely low sunspot frequency

Why did the eruption of volcanoes lower the temperature of the earth?

Sulfur gas blocks light from the atmosphere and the volcanoes erupting spewed this into the air

Pleistocene + holocene, represents the past 2.5 million years

Quaternary

2.5 million - 10,000 years ago, included 11 glacial and interglacial cycles

Pleistocene

the last 10,000 years

holocene

How far down did the ice sheet reach?

Northern Kentucky

How long ago was the younger dryas?

12,900 years ago

What happened during the younger dryas?

the earth flew through rocks, the rocks got into our atmosphere and crashed to earth, breaking up lake Agassiz

Why is the younger dryas theory around the Carolina Bays not true?

Because the lakes would be 12,900 years old if they were formed by the younger dryas event but they are not

Dramatic climatic oscillations leading to the holocene

Dansgaard-Oeschger events

How many times have Dansgaard Oeschger events happened?

25 times

DO events present as rapid warming and slow cooling in which hemisphere?

the northern hemisphere

DO events present as slow warming and slow cooling in which hemisphere?

the southern hemisphere

What seems to be the cause of the Dansgaard-Oeschger events?

The ice sheet dynamics and the NADW

_________ events are typically called iceberg armadas

heinrich

How was the breakage of the ice sheet discovered?

Ice rafted debris

Layers of rock and sediment found in ice cores

Heinrich events

What is labeled as the last major cold period?

the 8.2 kiloyear event

What was the 8.2 kiloyear event?

the event when the ice sheet was fully melted back to where it is now

Measuring something that is calibrated to represent temperature

paleoclimate proxy

What main thing helps in measuring atmosphere in ice cores?

bubbles

what things can be measured in an ice core?

dust/charcoal shows if there were more or less fires during a time

what makes ice core data powerful?

annual layers

What is the most important oxygen isotope in ice cores?

del-O18

Since neutrons are considered as weight, and O18 has ____ neutrons, an O18 isotope is _____

10; heavy

Because _____ is lighter than ____, it evaporates easier

O16; O18

As the lighter O16 evaporates, the ocean with more O18 gets heavier during a ______ period

glacial

Where are ice cores from mainly?

Greenland, Antarctica, Glaciers

What is GRIP?

GReenland Ice core Project run by countries in the EU

what is GISP?

Greenland Ice Sheet Project run by Denmark, Switzerland and US

What is the Vostok project?

run by Russia, known to be the coldest spot on earth

What interesting thing is notable about Vostok?

underneath a mile and a half of ice, there is a megalake

What is EPICA?

European Project for Ice Coring in Antarctica, run by Europeans

what is Dome C?

Ice-coring area run by US, France and Italy

What does research in antarctica do?

helps us know if the Younger Dryas was hitting in the exact same year or did it take time to travel from pole to pole

What is powerful about Glacial cores?

high altitude glaciers can give us tropical ice cores

What is ODP?

The Ocean Drilling Project

What type of tracking is done on the cores from the ODP?

C14 dating

What is the half life for C14?

5,730 years

radiochemistry only works for ___ half lives so C14 can only be dated back ________ years

8; 40,000

What affect does C14 have on shells made by lake and ocean critters?

it causes them to appear older than they really are because the critters use both forms of oxygen

What is the reservoir effect or hard water effect?

when aquatic organisms appear older than they are when dated with C14

What is a way to avoid the reservoir effect?

measuring non aquatic items in sediment cores (ex: leafs, seeds, charcoal)

What organism can give us del-O18 measurements?

forams; testate amoebas

What are tests made of?

CaCO3

Why is the Ca in the CaCO3 tests from amoebas important for?

for every few Ca picked up, the organism picks up a Mg. This indicates sea surface temperatures at the time.

Tree ring proxies are limited in _____

age

Scientists use the length of the tree rings to measure _____

drought

what do big cells in tree rings indicate?

springw

what do small cells in tree rings indicate?

summer

what can be measured with pollen?

terrestrial change/ where trees moved

What is the quercus-pinus transition?

6,000 years ago, the SEUSA changed from oak to pine

If there is a marker for ragweed in pollen it indicates what?

the clear cut of a forest

what was the date given for the roanoke colony

1857

what was the date given for the jamestown colony

1606

what is an issue with tree ring data?

it is highly influenced so there can be extreme error

what index helps in understanding tree ring data?

the Palmer Hydrological Drought Index

What tree type was discussed in the lost colony paper?

baldcypress trees

despite the fact that bald cypress trees, a wetland tree, would be the last to respond to drought, they were used. why?

because they are endemic to the area and would have the longest history

What is whitening?

a statistical term for making a definite conclusion when there is a lot of variability in data

what are three ways to statistically argue/prove a model?

calibration, validation, application

the first half of data is used for calibration, during calibration you:

manipulate your model as much as you can to fit the known data

the second half of data is used for validation, during validation you:

use your model against known data to know how well you did

what does the R² value represent?

how much the percent of variance of your data set is represented by the line. the closer to 1% the better

historical data documented in tree ring paper

Juan Batista de Segura, a spanish monk documented famine in 1570

what is a pollen proxy used as?

a terrestrial signal to show what the forest has been doing through time

what is Reid’s paradox?

As the ice sheets melted, plant migration occurred because the ice sheet was moving back. However, the movement of the plants was very fast compared to the ice.

What are some theories for Reid’s paradox?

birds/animals moving seeds, refugia, pockets under the ice allowing seeds to perpetuate

how are diatoms used as a proxy?

they are used in lake health studies

What signal do diatoms give?

aquatic signals

what environmental factors do diatoms measure?

pH and salinity changes, ecology changes, nutrients, cold/warm water

what organism is often used in transfer functions?

diatoms

why is using diatoms so powerful?

they measure so many environmental factors and give us quantifiable data

what are charcoal proxies used for?

used to measure fire regime, used as a drought index

_______ is the main thing studied because it is the best to show a local fire signal

Macrocharcoal

how are chironomid head capsules used as a proxy?

the spikes on their heads completely respond to temperature

________ _____ _________ are one of the only proxies in lakes that give us temperature

chironomid head capsules

what proxy is great for measuring erosion?

titatnium

why is the Cariaco basin popular for environmental research?

it gives a tropical signal, it is anoxic, preservation

the Cariaco basin has a _____ year record

100k

which mass extinction took place 440 mya?

snowball earth

what is gondwanaland?

super continent over a pol

what mass extinction took place 365 mya?

large decrease in CO2 across earth based upon extreme plant growth

what mass extinction took place 250 mya?

the permian extinction

which extinction led to the most death ever in the history of the earth?

the permian extinction

what were characteristics of the permian extinction?

hot season, toxic (acid), marine life affected

what cause the permian extinction?

volcanism in the siberian traps

what happened with the siberian traps?

large crack that oozed lava non stop and emitted CO2 and CH4