Climate Change for Leaders Exam 1 Topic 1
What would have happened without the magnetosphere?
Earth would have lost most of its atmosphere
What did the layers of BIF used to be?
horizontal
In early oceans what dissolved element was highly present?
iron
What hematite and magnetite?
iron oxides
What were the first polluters of the atmosphere and ocea?
microbes
What happened to the oxygen in the atmosphere?
oxidized the land surface
What are the 3 components of BIF?
quartz, hematite and magnetite
What were these rusted rocks called?
red beds
What color did the iron in the ocean turn the water?
reddish to brown hue
What are the major steps of the history of the ocean?
formation of the moon, formation of magnetic field, volcanic outgassing of atmosphere, cooling and first precipitation, beginning of life, change to oxygenated ocean and atmosphere
What happened once there was no more iron?
free oxygen could dissolve and enrich the ocean
What did the photosynthetic microbes produce?
glucose and oxygen
How long was the overlap of BIF and red beds?
400 million years
How fast are the highly energized particles moving?
400km/sec
What happened to the new oxygen in the water?
Combines with iron and forms iron oxide
Before the great oxygenation event what was the % of atmospheric levels?
0.001
When did BIF stop forming?
1.9 bya
After the great oxygenation event what did the % of atmospheric levels rise to?
10
When we cyanobacteria abundant?
2.5-0.7 bya
How long was iron dissolving into the oceans for?
300 million years
When did photosynthetic microbes first emerge?
4 bya
When were the crystal rocks found in 2008 dated back to?
4.321 bya
When did it first rain?
4.3bya
How many years ago did earth form?
4.5 bya
What time period did the Earth cool from?
4.5-4.3 bya
What does the magnetic field do?
Acts as a shield and blocks solar wind around the earth
In the early earth where was there no free oxygen?
Atmosphere and ocean
What are the 2 sources of free oxygen in today's ocean?
Atmospheric oxygen and photosynthetic oxygen
What are the layers of the earth from outermost to innermost?
Crust, mantle, outer core, inner core
What happened to the layers of BIF?
Deformed by tectonics
What happened to the oxygen once the iron was gone?
Diffuse up into the atmosphere
What molecules can escape into space?
Helium and hydrogen
What does the solar wind consist of?
Highly energized particles(protons and electrons)
What color tint did the earth used to have?
Reddish
What is anoxic water?
The oxygen in H2O molecules can't be easily separated from the hydrogen
How is stromatolites built?
cyanobacteria holds together sand and mud, cyanobacteria gets buried by sand and mud, cyanobacteria grows through sand and mud to be near sunlight, cyanobacteria glues together layers of sand and mud
What is the magnetosphere?
The region of Earth's magnetic field shaped by the solar wind.
How is the magnetic field generated?
The rotation of the outer liquid core around the inner solid core
How do we know cyanobacteria was abundant?
They built stromatolites
What did the chemical signature of these crystal rocks imply?
They formed as seafloor basalts
Where did most of earth's water come from?
Volcanic outgassing
What are the 3 kinds of life?
bacteria, archaea and eukaryota
What are anatomical remains classified as?
body fossils
What are chemical signatures classified as?
chemical fossils
What happened to the iron oxide?
covered the seafloor
What were some of the earliest photosynthesizers?
cyanobacteria
What are tracks and traces classified as?
trace fossils
How was iron being added to the ocean?
underwater volcanoes
What is oxygenated water?
water contains free, dissolved oxygen that can be absorbed by organisms
