Key Concepts Flashcards
What is Silicate Rock Weathering?
Co2 + rainwater reacts with silicate rocks.= releases calcium magnesium and bio carbonate ions to the ocean where they react to form carbonate rocks. These eventually go to the earths crust which removes carbon from the atmosphere over longer periods of time.
Usually balances the carbon released by volcanic activity
Occurs faster under warmer climates
Plant Acidic Weathering?
Plants can cause mechanical and chemical weathering. When plants cause mechanical weathering, their roots grow into rocks and crack them.It can also happen in streets or sidewalks. When plants cause chemical weathering, there roots release acid or other chemicals, onto rocks, which then forms cracks, and breaks apart.
Solar luminosity + greenhouse gasses / weathering = 2:1
Assuming it happens at the same time
Snow ball earth?
= the earths climate could be tipped into a frozen state which would be just as stable as it is today just frozen aka the ‘snowball earth’
Ice and snow are reflective to the sun meaning that the earth wouldn’t heat to the same degree (high albedo)
= if something caused the earth to cool down *like a drop in atmospheric carbon ‘ the snow would expand = reflecting even more sunlight = cylchred adborth postif
= amplify carbon change in either direction= if there Is a higher albedo where there’s more sun radiation more of it will be reflected again causing the earth to cool further
= if it hits a 30* latitude to the tropics it’ll get to the point that the feedback ‘runs away’ = any cooling will cause that more ice coverage = a snowball earth= can only happens if the feedback loop accelerates by 100%
= the output of carbon from volcanic activity would eventually increase and melt through the ice sheet causing a negative feedback loop and beginning to revert it back to it’s original state.= meagre flux of heat due to the new sheet of carbon = heating things up again= could lead to another ‘ice albedo feedback loop’ leading to the earth re freezing
Ozone Molecule = 3O
Stratospheric ozone depletion?
When chlorine and bromine atoms come into contact with ozone in the stratosphere, they destroy ozone molecules. One chlorine atom can destroy over 100,000 ozone molecules before it is removed from the stratosphere. Ozone can be destroyed more quickly than it is naturally created
Chlorofluorocarbons
Or CFCs , are nontoxic, nonflammable chemicals containing atoms of carbon, chlorine, and fluorine. They are used in the manufacture of aerosol sprays, blowing agents for foams and packing materials, as solvents, and as refrigerants.- predicted by Mario Molina and Sherwood Rowland that CFO’s would lead to a 7% loss of stratospheric ozone over the next 50-100 years
How did the moon form ?
Collision with Theia (planet size body) resulted in the formation of the Mood at 4.25 Ba= dictates how life in the ocean works = tides
How did abiogenesis affect life on earth?
abiogenesis, the idea that life arose from nonlife more than 3.5 billion years ago on Earth. Abiogenesis proposes that the first life-forms generated were very simple and through a gradual process became increasingly complex.
How did cyanobacteria lead to photosynthesis?
Stromatolites –cyanobacteria = change the earths atmosphere and increasing the earths atmosphere
Cyanobacteria use the energy of sunlight to drive photosynthesis, a process where the energy of light is used to split water molecules into oxygen, protons, and electrons.
What are the three hypothesis for the origin of molecules on early earth?
1)Organic synthesis sources (such as ultraviolet light or electrical discharges) : the miller- Urey experiments in the synthesis of amino acids – generated from non biological = ultra violets or electrical discharges to create them
2)Delivery by extra terrestrial objects such as carbonaceous meteorites or chondrites
3)Organic synthesis driven by impact shock aka Theia
Where did water come from ? What are Extraplanetary Sources ?
(comets, water-rich meteoroids/protoplanets): based on isotopic ratios of deuterium to protium (D/H) in comets such as Halley and Hale-Bopp that are double that of oceanic water. == is this why the ratio of oceanic water changed over time
Water in comets is different from oceanic water
Orrr water was already present when the early earth was formed- water samples are very similar to the earth supporting the hypothesis
Internal Sources: small amounts derive from volcanism – hydrate minerals – when they dehydrate the water is released
What is Darwins Evolution theory ?
According to the paper written by Darwin and Wallace in 1859 more individuals are produced than will survive.Those that are produced fight for survival and those that survive re create. Those that recreate pass on variations (aka natural selection)
What is Alfred Russel Wallace’s Theory ?
Alfred Russel Wallace noted the similarities and differences between nearby species and those separated by natural boundaries in the Amazon and Indonesia. Independently they came to the same conclusion: over generations, natural selection of inherited traits could give rise to new species
Natural System Theory
*Systems consist of a series of interacting components within a defined external boundary.
*Most systems are open = flow of energy and mass withing and out of the system through throupute
+Some systems are closes = every trasnfer of mass and energy happens within
What’s in the system isnt determined…..
by the place of the reaction rather than the timescale e.g tectonic processes won’t be included in some hence how the crust and mantel are considered a whole other set of processes
Earth system is therefore split into 2 – the surface of the earth that supports life – and the inner/ underneath of the world
To be a part of a system energy…
has to be recycled – can be abiotic or biotic
How is long wave energy created?
Heat resulting from the absorption of incoming shortwave radiation is emitted as longwave radiation. Radiation from the warmed upper atmosphere, along with a small amount from the Earth’s surface, radiates out to space. Most of the emitted longwave radiation warms the lower atmosphere, which in turn warms our planet’s surface.
The Solar Constanent
A solar constant is a measurement of the solar electromagnetic radiation available in a meter squared at Earth’s distance from the sun. The solar constant is used to quantify the rate at which energy is received upon a unit surface such as a solar panel. In this context, the solar constant provides a total measurement of the sun’s radiant energy as it is absorbed at a given point. (aka how much sun reaches the earth at any given point)
varies by 0.2% every elevan years
Greenhouse gases
Earth’s greenhouse gases trap heat in the atmosphere and warm the planet. The main gases responsible for the greenhouse effect include carbon dioxide, methane, nitrous oxide, and water vapor (which all occur naturally), and fluorinated gases (which are synthetic)
Greenhous gasses used to be 200-280 ppm but now its about 400-420 ppm
CaSiO3 + 2H2O + 2CO2 → CaCO3 + SiO2 + 2H2O + CO2 = silicate weathering…
reduces the amount of carbon in the atmosphere
look at the carbon at the start of the equation and at the end
Stomata is the leaf and messuring carbon?
co2 input in the lead = you can grow different species in dofferent co2 conditions. More co2 = bigger stomata = allows us to tell how much co2 was in the atmosphere through fossils
Ice sheets are archives of co2
every year you can see the annual build up, - greenland is the oldest and 130,000 years =Antartica is a million years old, people think it can get to 2 million years old
Air is present in the sea crystals and messruing CO2
the air goes from and open to a closed system- their a direct measure of the atmosphere of the past.
cyanobacteria was the first to do what ?
photosynthesize
3ba years ago
How often does The oscillations in the Earth’s axial tilt occur?
on a periodicity of 41,000 years from 21.5 to 24.5 degrees.
What is a sidereal day? How does this effect the length of the day?
One complete rotation of the Earth around its axis takes 24 hours with respect to the Sun, but slightly over 23 hours and 56 minutes with respect to the stars – this is known as a sidereal day= slightly different definition
Where is the The axis of rotation is located
The axis of rotation is located at the geographic North and South poles. These are distinct from Earth’s magnetic poles. - earth magnetic poles are weaking by 5% every year and could be 0 in another thousand years at this rate.
How long does it take for the earth to orbit the sun?
One complete orbit takes 365.256 days (one sidereal year= accurately defined year= this is why once every four days we have a leap year), hence a leap year occurs once every four years (February 29th)
The tilt of the Earth’s axis also defines the length of daylight. Explain
Daylight hours are shortest in each hemisphere’s winter. Between summer and winter solstice, the number of daylight hours decreases, and the rate of decrease is larger the higher the latitude. The fewer sunlight hours the colder the nights
How fast Earth spins determines the number of hours in a given day. Explain.
As Earth orbits the sun it spins about its axis approximately once every 24 hours. But this is slowly changing with time. About 650 million years ago there were only about 22 hours in a day
