Key Words Flashcards
Finite Systems
A perception shift- the idea existed that the planet was too big for us to ever have an effect - this is not true
Positive Feedback Systems
a sequence of event that work to further the system
Negative Feedback Systems
dampens / slows down / stops changed within the system
Axial Tilt
Axial tilt is the angle between the planet’s rotational axis and its orbital axis. A planet’s orbital axis is perpendicular to to the ecliptic or orbital plane, the thin disk surrounding the sun and extending to the edge of the solar system
Political Dimensions to Feedback Loops
each society and political movements effect feedbacks and therefore each group effects the system differently.
Abiogenesis
the natural process by which life arises from non-living matter-life forms the self replication of molecules based on a chemistry based on carbon and water. 4 key : lipids (fatty cell walls), carbohydrates, amino acids (protein), nucleic asids (DNA and RNA)
Ba
Bilion Amon = bilion years
What is Abiotic Oxygen ?
Oxygen from non biological sources .
Oxygen is considered a biosignature, but there are chemical processes that can generate oxygen gas without the presence of living organisms, e.g., chemical reactions that break down water.
What are Prokaryotes?
Prokaryotes are organisms whose cells lack a nucleus and other organelles. Prokaryotes are divided into two distinct groups: the bacteria and the archaea, which scientists believe have unique evolutionary lineages. Most prokaryotes are small, single-celled organisms that have a relatively simple structure.
What are Eukaryotes?
any cell or organism that possesses a clearly defined nucleus. The eukaryotic cell has a nuclear membrane that surrounds the nucleus, in which the well-defined chromosomes (bodies containing the hereditary material) are located
What are Stromatolites?
layered mounds, columns, and sheet like sedimentary rocks formed by the incremental growth of layer upon layer of cyanobacteria, a single-celled photosynthesizing microbe
aka the living rock
What are multicellular organisms (Metazoa)?
All multicellular organisms, from fungi to humans, started out life as single cell organisms. These cells were able to survive on their own for billions of years before aggregating together to form multicellular groups.
What is the Principle of Uniformitarianism?
the operations of nature are consistent, slow and not goal-directed (anthropocentric).
Uniformitarianism, also known as the Doctrine of Uniformity or the Uniformitarian Principle, is the assumption that the same natural laws and processes that operate in our present-day scientific observations have always operated in the universe in the past and apply everywhere in the universe.
What is Phylogeny?
a family tree of species
Gradualistic vs. punctuated equilibrium models of evolution
Natural selection vs human breeding species
What is the equation for Silicate Rock Weathering?
2CO2(s) +3H2(s)0 + CaSiO3(s)= Ca2(+) +2HCO3(s)(-) + H4(s)SiO4
Lithsophere
lithos = rocks
dynamic of tectonics
Cryosphere
comprises all the solid ice which is frozen water but it’s so important in the earth system it’s considered separate from the hydropshere
Atmosphere
Oxygen and Nitrogen account for 99% if the volume of the atmosphere
Hydrosphere
Water
97% of the water on earth is in the ocean.
Biosphere
plant and life on top of the lithosphere.
Outer Boundry
Outside of the earth e.g. the sun
provides the earth w energy that drives the earth but is not effected by the systems. Large amounts of energy are exchanged across the top of the atmosphere but relatively little matter. Some hydrogen atoms can escape Earth’s gravity into space, and some meteoric material crosses into the Earth system (~44 tonnes per day on average)
Transfers of energy and sometimes transfer of Mass
Inner Boudry
The whole earth interior
The Earth has its own internal heat source (fueled by radioactive decay and heat remaining from the accretion of the planet) that drives plate tectonics: geothermal heat.
There are parts of the inner earth that are fundamental to life on earth
Open Systems
the earth itself is an open system, inputs of mass and energy e.e. meteorites. Subsystems are also open systems. Nested in a hierarchy of systems.
Glaciers and ice sheets are natural open systems- inputs: precipitation, rock detritus, gravity, insolation, geothermal heat. Outputs: water vapor, water, ice, rock detritus, heat. Throughputs: precipitation and transfer of energy (stuff that moves through the system)
Closed Systems
ice sheets build up over millions of years, in the antartica the ice Is over a million years old, in the ice are bubbles of ice that are trapped , if you melt the ice and release the air you get samples of the earths atmosphere from millions of years ago. At the top of the ice sheet is snow as the snow compacts into ice more air traps and creates more bubbles which does not exchange with the atmosphere creating a closed system.
Dynamic Equilibrium
A reversible process is said to be in dynamic equilibrium when the forward and reverse processes occur at the same rate, resulting in no observable change in the system. Once dynamic equilibrium is established, the concentrations or partial pressures of all species involved in the process remain constant.
Homeostatic Adjustment
Adjustment of physiological systems within the body is called homeostatic regulation, which involves three parts or mechanisms: (1) the receptor, (2) the control center, and (3) the effector. The receptor receives information that something in the environment is changin
What is the name of the place that has evidence of a snowball earth?
Nambia
the isotopic ratio suggests thar carbon was removed from the ocean through half chemical and half biological processes-as the icea spread the earth the carbon capture by biological processes began to decrease- the glacial deposit itself doesn’t preserve a faithful isotopic record. But an overlying carbonate layer suggests that biological productivity had dropped all the way to zero, and recovered only slowly.
Paleolatitude (and it’s climate?)
o ice sheets during the Jurassic period (different periods have different ice coverage)-back in the cryogen era the entire earth was covered in ice = snowball earth (marinoan and the Strution in the Neoproterzoic period)
What is the Kirchvink Mechanism 1992?
Extended cold means that oceans start freezing= lowered reflectivity (aka more albedo) means the earth freezes further=Co2 cycles in the ocean stops = outgassed volcanoes builds up (co2 can’t be absorbed back into the ocean as the snowball stops it)= strong greenhouse gasses get released melting the snowball earth leading to a “hothouse earth”-Co2 cycle restarts and starts pulling it back into the ocean and the planet starts to go cold again. - negative feedback on the back of a positive feedback due to the greehouse effect
The Claw Hypothesis
The Claw Hypothesis- provides a mechanism by which plankton may modify climate through the atmospheric sulfur cycle via the provision of sulfate cloud condensation nuclei. The CLAW hypothesis was published over 20 years ago and has stimulated a great deal of research.
atmospheric sulfur cycle?
Sulfur is emitted into the atmosphere in a more or less reduced state as hydrogen sulfide, organic sulfides, or as sulfur dioxide. Much of it is then oxidized into sulfuric acid or its salts and removed mainly by precipitation
DMS = dimethyl sulphide
part of the claw hypothesis
H3C,S,CH3-s a gas produced by marine phytoplankton which is a major source of cloud condensation nuclei (diatoms)- comes from the ocean surface where it brakes down into sulfate irons = forms CCS
CCS-Cloud Condensation Nucliai (clouds reflect solar radtiation too)
Eocene Optimum
where the temperatures gradually went back to how they were
Zachos curve
a compilation of earth history over the years from different sources
reaction =response =relaxation time
Perturbation or an event at T1- so the biomass or mass is no longer in equilibrium – so it stays the same for a while but slowly we see a change in distribution – if there’s no change in the first variable then it reaches a new equilibrium (T2) (Response time, relaxation time, reaction time, or lag time)
All species will have different lag times but there will always be one
e.g the Brown Argus , they move more northward due to the anthropogenic climate warming
Name three examples of reaction = response = relaxation time
Atmosphere = days/months/years
Forest Vegetation = centuries
Plate Tectonics = Tens millions of years
The Brethan Diagram
‘ gives a view of the earth as a set of system operating a wide range of spatial and temporal scales rather than a collection of individual components’
Accretion
In planetary science, accretion is the process in which solids agglomerate to form larger and larger objects and eventually planets are produced. The initial conditions are a disc of gas and microscopic solid particles, with a total mass of about 1% of the gas mass= drives tectonic processes – not all planets have tectonic processes- ‘outisde’ of the og system as it’s an array of its own systems that co-incide with the main system process
Convection cells
the movement of magma and heat
Continental crust
low density allows it to float creating land.
acoustic techniques
The technique used to find out about oceanic crust
the sound waves after a tectonic event (e.g an earthquake) travel at different speeds through the rocks allowing us to know what rock and density is where
Destructive plate margin
where the plate melts
Atlantic center
spreading center
Crud forming
lighter material that forms on the surface – doesn’t go back down- forms bigger lumps = land= silica rich
Lithosphere-asthenosphere boundary (LAB)
compare the matter and durability between the two
The boundary between Earth’s rigid lithosphere and the underlying, ductile asthenosphere is marked by a distinct seismic discontinuity. A decrease in seismic-wave velocity and increase in attenuation at this boundary is thought to be caused by partial melt.
Ductility
measures a solid materials ability to deform.
radioactive heating
Broken into tectonic plates which are moved by slow currents powered by radioactive heating believed to cause lateral movements
Moves about 2.5-5 centimeters a year
Alfred Wegener
He believed that all the continents were once connected as different fosils from different areas matched e.g South America and Affrican Coastlines
He came up with the idea that during the Paleozoic Era (which ended about 252 million years ago) all of today continents were one super continent = Pangea
Pangaea
Pangea existed between about 299 million years ago (at the start of the Permian Period of geological time) to about 180 million years ago (during the Jurassic Period). It remained in its fully assembled state for some 100 million years before it began to break up
what is a continent super cycle?
-Continents combine to form supercontinents like Pangea every 300 to 500 million years before splitting apart again= super cycle
What did Harry Hess do?
created a complete map of ocean floors which helped prove tectonic theory.
Sound waves from the ship were used if there’s a submarine the sound waves bounce back and have a positive result
= two-way travel time, if it hits the ocean floor it has a diffused return (negative for submarine sound waves)
What did Fred Vine and Drummond Mathews discover? 1963
They found that the crust surrounding the midocean ridges showed alternating bands – each band magnetized with a polarity opposite the surrounding bands.
-As the magma comes out of the ridge and solidifies the rock aligns itself with the magnetic field- it was striped = it was completely different at different points in the past= it flips
the Jaramillo Event
Based off of Fred Vine and Drummond Mathews discovery
The wholesale reversal of Earth’s magnetic fields some 900,000 years ago. This confirmed the theory that Earth’s magnetic field had flip-flopped through the planet’s life, and it made Matthews and Vine’s 1963 finding quite clear. They realized that the pattern of reversals matched perfectly the magnetic profile they had compiled of the sea floor
Dan McKenzie, Cambridge, 1967
He suggested there are two layers in the mantle, each of which are in motion, controlling the movement and behavior of the tectonic plates above. ‘The viscosity of the lower mantle’ was published in 1966
= tectonics and sea floor spreadin
= convection cells = the hot magma rises and the dense cold magma sinks creating a cycle
Divergent Boundaries
When the plates move away from each other
Leads to earthquakes, and magma rising (molten rock ) to create new crust
The Mid Atlantic Ridge is an example of this plate boundary
Convergent Boundaries
or known as a destructive boundary
Where plates move towards each other
This can be divided into two types, subduction or collision depending on the density of the plates
Transform Boundaries
When two plates move side by side
broad zone forming as the Pacific Plate slides northwestward past the North American Plate, including many lesser faults in addition to the San Andreas Fault
Columnar basalt, Iceland Case Study
Basalt is a volcanic rock formed from the superheated magma that emerges as lava during an eruption. The iron and magnesium-rich basalt lava cools and contracts very quickly once exposed to the surface air and hardens as it solidifies.
Iceland basalt columns are the result of this rapid cooling process that changes the chemical makeup and appearance of the lava. Basalt volcanic rock has a special geometrical shape due to this change in composition.
These basalt pillars and hexagonal rock formations you see have a special feature called columnar jointing. This is what gives each basalt column their unmistakable hexagonal shape and makes them so neat to look at.
Mantle convection ?
Mantle convection describes the movement of the mantle as it transfers heat from the white-hot core to the brittle lithosphere. The mantle is heated from below, cooled from above, and its overall temperature decreases over long periods of time. All these elements contribute to mantle convection
As magma goes to the top it cools, becomes more dense and sinks. Once it sinks moving towards the heat it becomes less dense and rises again
Benioff Zone ?
Benioff Zone - a The top of the descending plate, or slab, is recognised from seismic activity as the Benioff Zone, a zone of intense earthquake activity.
Basaltic lava
low viscosity, flows readily, and builds low relief shield volcanoes in spreading centres and oceanic hotspots such as Hawaii and Iceland
Basalt
a dark-coloured basic (mafic) alkaline extrusive (volcanic) rock of low viscosity extruded along mid-ocean ridges and spreading centres
Rhyolite
a light-coloured silicic acidic extrusive (volcanic) rock of high viscosity extruded along subducting margins generating highly explosive high-relief stratovolcanoes.
Mount St Helens
Helens sparked the advances in cutting-edge volcano science and monitoring that exist today. Mount St. Helens turned out to be the ideal laboratory to study volcanic activity. The 1980 eruption was the first large explosive eruption studied by scientists and observers using modern volcanology
The May 18, 1980, eruption left a seared and smoldering landscape around Mount St. Helens. Entire forests were toppled by the hot blast. Most plants and animals perished, meadows were destroyed, and numerous new ponds and lakes were created.
Earths radiation definition quote
“The energy entering, reflected, absorbed, and emitted by the Earth system are the components of the Earth’s radiation budget. Based on the physics principle of conservation of energy, this radiation budget represents the accounting of the balance between incoming radiation, which is almost entirely solar radiation, and outgoing radiation, which is partly reflected solar radiation and partly radiation emitted from the Earth system, including the atmosphere. A budget that’s out of balance can cause the temperature of the atmosphere to increase or decrease and eventually affect our climate. The units of energy employed in measuring this incoming and outgoing radiation are watts per square meter (W/m2)”
Watt (unit of power)
= one joule per second
Ultraviolet
comes into the system (aka shortwave radiation) = helps drive the earths climate, some is reflected back up by clouds and some is absorbed by the earth. Some of the larger aerosol particles react with oxygen , further heating the earth.
Solar Constant
solar radiation that’s avareged over a long period of time
Short Wave Inolation
aka radiation that reaches the earths surface
Albedo
When the waves are reflected
Absorbed
when the energy is absorbed
LONG WAVE COUNTER RADIATION
Energy arriving from the Sun = Energy re-radiated by the Earth or directly reflected
Equilibrium temperature WITHOUT ATMOSPHERE = between -18°C and -30°C
The Stefan Bolzeman Constant
The Stefan-Boltzmann constant, symbolized by the lowercase Greek letter sigma (σ), is a physical constant expressing the relationship between the heat radiation emitted by a black body and its absolute temperature. (Thermos dynamic temperature)
Evaporation
the process of turning from liquid into vapour
Precipitation
Precipitation is any liquid or frozen water that forms in the atmosphere and falls back to the Earth. It comes in many forms, like rain, sleet, and snow. Along with evaporation and condensation, precipitation is one of the three major parts of the global water cycle
The Coriolis Effect
the result of Earth’s rotation on weather patterns and ocean currents.
Atmospheric circulation cells
The global circulation can be described as the world-wide system of winds by which the necessary transport of heat from tropical to polar latitudes is accomplished
There are three cells included in this : The Hadley Cell, The Ferrell Cell and then Polar Cell
The Troposphere
the name given to the vertical extent of the atmosphere from the surface, right up to between 10 and 15 km high. It is the part of the atmosphere where most of the weather takes place.
Hadley Cell
largest cell , 30 and 40 degrees north and south.
the trade winds blow towards the equator, then ascend near the equator as a broken line of thunderstorms, which forms the Inter-Tropical-Convergence Zone (ITCZ). From the tops of these storms, the air flows towards higher latitudes, where it sinks to produce high-pressure regions over the subtropical oceans and the world’s hot deserts, such as the Sahara desert in North Africa.
Ferrell Cell
- Low alttitudes
*Suptropical Air
*60-70 degrees north and south
*Works with the Hadley Cell
*Moves opposite other winds like a gear
*Deflection is caused by the coloris affect
Polar Cell-
Weakest cell. Extend from between 60 and 70 degrees north and south, to the poles Air in these cells sinks over the highest latitudes and flows out towards the lower latitudes at the surface
Inter-Tropical-Convergence Zone (ITCZ)
The Inter-Tropical Convergence Zone (ITCZ - pronounced “itch”) appears as a band of clouds consisting of showers, with occasional thunderstorms, that encircles the globe near the equator. The solid band of clouds may extend for many hundreds of miles and is sometimes broken into smaller line segments.
jetstream
*Narrow bands of strong winds
*Upper atmosphere
*Goes from West to East
*Can shift from North to South
*Boundries of Hot and Cold
cyclogenesis
Cyclogenesis is defined as any development or strengthening of cyclonic circulation in the atmosphere. In certain coastal regions, cyclogenesis is a very important phenomenon, for example, along the mid-Atlantic coast of the United States and in the northwestern Gulf of Mexico
The Montreal Protocol (1987)
signed by 59 countries to ban CFC use. It remains the single most effective international agreement in environmental legislation. The “ozone hole” was interpreted to have started to heal in 2016.
Marina Molina and Sherwood Roland
created a model that would predict the destruction of the ozone layer, they predicted a 7% loss over the next 50-100 years. In reality it was much worse than this.
Icehouse period
aka when we have ice sheets
the deep ocean floor is oxygenated, and oceans are well-mixed.
When continental positioning allows north-south ocean circulation to bring warm equatorial water into polar latitudes where it evaporates and generates snowfall e.g the Quaternary period
Greenhouse Fazes
no ice sheets = intense Co2 in the atmosphere
Soft Rock =
Till
unsorted material deposited directly by glacial ice and showing no stratification like Clay
Hard Rock =
tillite
made up of sediment that was carried or deposited by a glacier and later cemented to form rock. It consists of a fairly fine-grained matrix that contains pebble to larger size pieces of distinctive rock types.
helps determine the conditions of ice house conditions
the Kirschvink mechanism (1992)
aka a snowball earth.
Gondwana
the super continent- 300 million years ago- high latitude southern hemisphere, tillite deposits show glaciation
The Mer de Glace, French Alps- glaciers present in a high mountain enviroment – evidence
The Mer de Glace, French Alps
glaciers present in a high mountain enviroment – evidence - evidence of Gondwana
Residence times
how long something is somewhere before being transported through the cycle e.g carbon in the atmosphere
Whats the equation for Photonsynthesis?
6CO2 (carbon dioxide) + 6H20 (water) ——> C6H12O6 + 6O2
Living stromata lights
map like reefs which are formed throw cyanobacteria = fossilize quite well.
Definition of Anaerobic respiration ?
is the type of respiration through which cells can break down sugars to generate energy in the absence of oxygen
The equation for anaerobic respiration is ?
C6H12O6+ 6O2 —-> 6CO2 + 6H202 + Energy ATP
The redox boundary in aquatic sediments is?
the depth below the sediment–water interface that separates the stability fields of the oxidized and reduced species of a given redox couple. It is loosely represented by the boundary between oxic and anoxic sediment.
How does Hydrogen Sulfate gas get produced?
it gets produced when there isn’t a lot of free oxygen available to break down the sediment
What are the two most important nutrients ?
phosphorus and nitrogen
Primary production and organic carbon burial are regulated by the supply of nutrients to land and ocean. The two most important nutrients are phosphorus and nitrogen. These have very different biogeochemical cycles; the largest reservoir of nitrogen is in gas phase in the atmosphere whereas phosphorus has no significant gas phase.
Apatit
has lots of phosphorus- fungus can dissolve t and create phosphate and becomes available to plants
Alfred Redfield 1934
Alfred Redfield observed in 1934 that the atomic ratio (stoichiometry) between carbon, nitrogen and phosphorus in phytoplankton and throughout the deep oceans is:
C:N:P = 106:16:1
The Blue Marble
is an incredibly detailed, true-color depiction of the Earth. NASA is responsible for this dataset made from a compilation of satellite images throughout 2001.
Magnetic poles
The magnetic pole is the region where the external magnetic field is the strongest at each end of a magnet. A pole of a magnet may refer to a magnetic monopole, a hypothetical elementary particle
Atomic clocks
demonstrate that a modern-day is longer by about 1.7 milliseconds than 100 years ago, increasing the rate at which Coordinated Universal Time (UTC) is adjusted by leap seconds. Analysis of historical astronomical records shows a slowing trend of 2.3 milliseconds per century since the 8th century BC.- the day is longer so it reflected that the earth spinning around the axis is getting shorter
Secular variations
Secular variation describes continuous drift in the intensity and direction of the Earth’s magnetic field (Bloxham and Gubbins, 1985). Such changes are noticeable over relatively short periods of time (tens of years) and thus magnetic charts need to be updated periodically to accommodate them.
Earth’s rotation around the sun, axis of rotation, and axial tilt are
3 seperate conponents
Stromatolites
record holders of seasons and days = the bio chemistry tells us about the variation in the earths cycle.
Plane of the ecliptic
the plane in which the earth is orbiting
axial precession, also known as precession of the equinoxes.
Earth’s axial tilt actually oscillates between 22.1 and 24.5 degrees. The reason for this changing obliquity angle is that Earth’s axis also wobbles around itself. This wobble motion is called axial precession, also known as precession of the equinoxes. It is caused by the gravitational force from the Sun, the Moon, and other planets.= a complete wobble takes around 26,000 years.
Perihelion
when the Earth is closest to the sun during one rotation (peri= close too , hellion = sun)= closest to the sun in January
Aphelion
when the Earth is furthest away from the sun during one rotation(ap = far ) in July
Whats the difference between Aphelion and Perilhelion?
the difference is a few million miles = significant but not significant
What is gravity?
natural phenomenon by which all things with mass are brought toward (or gravitate toward) one another, including objects ranging from atoms and photons, to planets and stars. Gravity is most accurately described by the general theory of relativity (proposed by Albert Einstein in 1915) which describes gravity not as a force, but as a consequence of the curvature of spacetime caused by the uneven distribution of mass.
What is Obliquity ?
Obliquity is the tilt of Earth’s axis relative to the plane of the ecliptic
Sir Issac Newton 1687
In 1687, Sir Isaac Newton proposed that ocean tides result from the gravitational attraction of the sun and moon on the oceans of the earth.
What is Newton’s Law of Universal Gravitation
it states that the gravitational attraction between two bodies is directly proportional to the product of their masses, and inversely proportional to the square of the distance between the bodies. Therefore, the greater the mass of the objects and the closer they are to each other, the greater the gravitational attraction between them.
The phases of the moon influence what type of tide
Spring tide
a component of high tides
Spring tides result from the gravitational alignment of the sun and the moon. These coincide with new and full moons.
Are the sun and moon working together or against each other in creating the tide ?
2 week cycle
Neap tide
low tide
= two week cycle
Neap tides result from the sun and moon at right angles to each other so their gravitational pull is not aligned.
Are the sun and moon working together or against each other in creating the tide
Lorrantied ice sheet?
25,000 years ago – ice sheet over America – Climap 1976
Swnda shelf?
the islands that compirsed idnonesia were connected w eachother
Landbridges
allow organisms to migrate = vegetation is slower
Pluvial
A word for high sea level
What are Platonik Foraminifera
Planktic foraminifera are single-celled marine eukaryotes characterized by having calcareous shells. They are holoplankton with 40–50 identified species in the world ocean.
What is Oxygen-isotope fractionation?
Isotopic fractionation is defined as the relative partitioning of the heavier and lighter isotopes between two coexisting phases in a natural system.
Fractionation
any natural process (physical or chemical) that differentiates between different isotopes of an element and alters their average natural isotopic ratio
Evaporation
lighter H216O preferred, particularly by colder air masses. Condensation around heavier 18O nucleii: Rayleigh distillation
Impact of glaciation on δ18O values
Leads to an ice age and or snowball earth
Evaporation (Water Cycle)
transfer of water from the surface of the Earth to the atmosphere. By evaporation, water in the liquid state is transferred to the gaseous, or vapour, state
Transpiration (Water Cycle)
Is the evaporation of water through minute pores, or stomata, in the leaves of plants.
Evapotranspiration (Water Cycle)
Transpiration and Evaporation together,
For practical purposes, transpiration and the evaporation from all water, soils, snow, ice, vegetation, and other surfaces are lumped together and called evapotranspiration, or total evaporation.
Water vapour
is the primary form of atmospheric moisture. Although its storage in the atmosphere is comparatively small, water vapour is extremely important in forming the moisture supply for dew, frost, fog, clouds, and precipitation. Practically all water vapour in the atmosphere is confined to the troposphere (the region below 6 to 8 miles [10 to 13 km] altitude).
Condensation (Water Cycle)
The transition process from the vapour state to the liquid state is called condensation. Condensation may take place as soon as the air contains more water vapour than it can receive from a free water surface through evaporation at the prevailing temperature. This condition occurs as the consequence of either cooling or the mixing of air masses of different temperatures. By condensation, water vapour in the atmosphere is released to form precipitation.
Precipitation
Everything that falls from the sky except bird poop.
Precipitation that falls to the Earth is distributed in four main ways: some is returned to the atmosphere by evaporation, some may be intercepted by vegetation and then evaporated from the surface of leaves, some percolates into the soil by infiltration, and the remainder flows directly as surface runoff into the sea. Some of the infiltrated precipitation may later percolate into streams as groundwater runoff. Direct measurement of runoff is made by stream gauges and plotted against time on hydrographs.
Accumulation (Ice Sheets )
is primarily by snowfall and is strongly linked to surface albedo
Ablation (Ice sheets)
is primarily controlled by atmospheric and ocean temperatures.
Ice Sheets formation
Mass balance of a glacier or ice sheet is a function of the balance between inputs (accumulation) and outputs (ablation).
primary producers
Plant are primary producers
Plants are primary producers that, through photosynthesis, manufacture organic molecules such as carbohydrates and lipids from raw inorganic materials (CO2, water, mineral nutrients). Primary productivity is thus a fundamental determinant of both the structure and functioning of terrestrial biomes
Whats the equation for ff
6Co2(s) +6H2O —ff—-> C6(s)H12(s)O6(s) + 6O2(s)
Ecosystems and trophic structure
The trophic structure of ecosystems is often described in terms of broadly defined levels consisting of primary producers, primary and secondary consumers, decomposers, and so on. Food webs, on the other hand, are described in terms of individual species.
Sunspot cycles
intervals when sunspots are abundant are times when strong solar emissions from the Sun’s polar regions and from the bright margins of the sunspots send increased levels of radiation to Earth- the more sunspots mean the more insolation were receiving
solar cycle.
Sunspots are seen to appear and disappear over an 11-year cycle called the solar cycle. These cycles were defined by the astronomer Rudolf Wolf who started numbering the cycles, with the 1755–1766 cycle as cycle 1. We are currently coming to the end of cycle 24.
Rudolf Wolf
These cycles were defined by the astronomer Rudolf Wolf who started numbering the cycles, with the 1755–1766 cycle as cycle 1. We are currently coming to the end of cycle 24.
Extreme ultra violet radiation (EUV)
The 11-year sunspot cycle results in a 0.1% variability in total irradiance output. There are also changes in the spectrum of radiation emitted during sunspot cycles Extreme ultra violet radiation (EUV) peaks at the time of the solar maxima, increasing by 10%.
Only small changed due to solar output
Not the quanity but quality of the radiation- peaks of extreme euv- it increase by 10% during the peaks
Spörer and Maunder
Sunspot cycles, and solar irradiance, have been observed to vary over time. The first to observe these changes were Spörer and Maunder during the period of low sunspot activity between 1645 and 1715 now known as the Maunder Minimum.
the Maunder Minimum.
the period of low sunspot activity
Radio carbon dating
is how we date things- has to be something that was living once-not stable isotopes
Solar variability and cosmogenic isotopes
Can date specifically using dendrochronology – using tree rings – an absolute timescale
Radiocarbon calibration curve
it’s fairly good linear fit. It has these huge wobbles- suess identified these’ suess wiggles’ the wobbles within the graph
What causes wiggles in Radiocarbon calibration curve
enhanced sun radiation means theres low radio carbon producution as it reflects the neurons back to space = we can use radio csrbon to see how strong the sun is.
produced through cosmogenic activity =
= cosmogenic isotope
10Be is alos a cosmogenic isotope – recorded through the ice core record
The Hockey Stick Curve
shows the temperatures in the Nothern Hemisphere
Medival climate anomoly
The cold area is the little ice age – 1400-1850 = northern Europe particularly = it was colder than the medieval times
Maunder sunspot minimum is also the period where the little ice age was at it’s coldest.
The sun is rotating around it’s onw axis slightly faster than the earth is rotating around the sun
THE OCEAN HEAT TRANSPORT AND OCEANIC GATEWAYS HYPOTHESIS
(SHACKLETON/KENNETT HYPOTHESIS)
Drake Passage opened 25-20 Ma BP and allowed strong circumpolar Antarctic Current to flow unimpeded around Antarctica. TheTasman gateway between Australia and Antarctica had opened 15 Ma earlier.
The Shackleton-Kennett Hypothesis
Antarctic solar current – it evolved because of plate tectonics – Antarctica stayed where is was but the rest of the continents moved- continental separation allowed the solar currents to flow- thermally blocks ocean currents = forces them a specific way because of the configuration of the north Atlantic- land bridges control and stop the ways in which warm water moves.
Opened 25 million years ago allowing hot water flows through – too late for this explanation to be correct (the break up of Gondwanaland)
Opening of the great passage is very important – measures in Sverdrup
Even tho the timing are wrong is definitely had an effect on the cooking
The BLAG Hypothesis
Glaciation of Antarctica after
35 Ma BP
THE “BLAG” SEAFLOOR SPREADING RATE HYPOTHESIS (BERNER, LASAGA AND GARRELS “BLAG” HYPOTHESIS)
Seafloor spreading rate as much as 50% faster 100 My BP
Atmospheric CO2 and global climate are controlled by global mean rate of seafloor spreading, which controls the global rate of CO2 input at ocean ridge crests and subduction zones
Links it to the greenhouse affect but linked to plate tectonics = the carbon cycle
Fast rates of spreading = fast rates more Co2 from both constructive and dectrustructive margin =
The BLAG hypothesis suggests there was a slowing in sea floor spreading forty million years ago
General gradient but there’s a tipping point
Paleomagnetic dating allows us to see how the rates of sea floor spreading
It’s the result of tectonics which is one of the external systems
=both hypotheses relate to the break up of Gondwanaland they just look at different parts of the same tectonic story
Orogenesis
Orogenesis is the term used for mountain building. A common geologist joke is that ‘subduction leads to orogeny. ‘ Orogenesis is often the byproduct of a continent-ocean subduction zone, where a volcanic belt is forme
The BLAG hypothesis
seafloor spreading
The RAYMO-RUDDIMAN
uplift weathering
The SHACKETON-KENNETT
Antarctic Circumpolar Current
What is the The SHACKLETON-KENNETT Hypothesis
invokes a change in oceanic heat distribution forced by tectonics
Earth system modelling by de Conto and Pollard demonstrates that it is the lowering of CO2 that is critical to the onset of Antarctic glaciation at 34 Ma, not the development of the Antarctic Circumpolar Current.
All three mechanisms derive from the breakup of Gondwanaland.
Homo
our direct ancesterol line
evolved in east Africa ~3 million years ago. Converting the age of the Earth to 24 hours, this is one minute before midnight…H. sapiens evolved 2 seconds before midnight.
Hominini
taxonomic tribe of subfamily of Homininae, includes genus Homo but excludes Gorilla
The Out of Africa Hypothesis
Homo sapiens evolved in East Africa probably around 200 ka and after the Last Interglacial (125 ka) spread throughout the other continents.- e.g got to australio around 50,000 years ago, 16,000 years ago in North America, South America was the last continent
What were the four / maybe five / types of homo 50,000 years ago?
Neanderthals, Denosovans, H. floresiensis and H. luzonensis and H. Sapiens
H. floresiensis
has an earlier evolutionary pathway than the other three species
H. sapiens
evolved in the East African Rift Valley ~200 ka and then migrated Out of Africa to all other continents except Antarctica
The neolithic transition
not a hunter gatherer community – had arrow heads to hunt from a safe distance – community and different jobs – time of the curation of plants and seeds and breeding animals – fundamental transition for the cultural development in Europe- diversification of function – some people would grow crops, some would grow livestock and some are in charge of protection and warfare. Phycological change as well – fencing the area became yours in a sense- you become concerned some people might steal it- the onset of the period of anxiety
The reflooding of the black sea hypothesis
the black sea was cut of from the Mediterranean – so its sea level was lower- turned into a lake and dried out- the land that was exposed was available for communities to grow food and have animals in a disorganized way, then the black sea re flooded when the sea level rose = waterfall lead to refill was rapid ( as seen by carbon dating )- this flooding forced the communities to grab their animals and move them quickly – lead to a de rooted remembrance of flooded which lead to the stimulus of the neolithic transition
The Last Millennium
The Last Millennium was characterised by three climatic phases: the Medieval Warm Period, the Little Ice Age and the post-Industrial Revolution warming
Observations on these changes are available for atmospheric (tree-ring) and marine (shell-based) temperatures
The forcings driving temperatures in the Last Millennium are well understood (orbital, volcanic, solar, greenhouse gas) and this enables climate model simulations based on these forcings
It is only by combining all forcings that the full details of the climate of the Last Millennium can be simulated. This is strong evidence supporting the conclusion that the recent warming is of anthropogenic origin.
The Ruddiman hypothesis
Scientist William Ruddiman is the lead proponent of the Early Anthropocene Hypothesis, which asserts pre-industrial land clearing and agricultural practices caused the release of historically underappreciated amounts of greenhouse gases, transforming the Earth
The Medieval Warm Period (Medieval Climate Anomaly)
was the result of high solar irradiance, low volcanic activity and high greenhouse gas loadings. The reduction in solar irradiance and greenhouse gas loadings, associated also with relatively high volcanic activity, resulted in the Little Ice Age. The post-industrial greenhouse gas loadings have been so high they have masked variability in solar irradiance and volcanic activity.
BUT, why did greenhouse gas loadings drop at the end of the Medieval?
Ruddimans second hypothesis?
Pandemic in the 1500 hundreds – there were a series of pandemics between 1300-1400- the only time where the human population is thought to have decreased
This caused a reduction in agriculture –a natural re foresting and therefore a reduction of co2 in the atmosphere
So, this hypothesis relates to the climate in the last millennial and the role of plagues and the population which helps the earth system resume its natural trajectory towards the next glacial period, as seen by the little ice age
Eutrophication
Eutrophication is a natural process that can be enhanced by human activity through nutrient loadings from sewage, detergents and fertilizers
Eutrophication derives from the Greek eutrophos meaning “well-nourished”. If an ecosystem is enriched with nutrients (nitrate, phosphate) and inorganic minerals, this causes enhanced productivity. This increases respiration which removes oxygen from the system. This ultimately limits, or completely stops, respiration and the system becomes anaerob
Parameterize
where you put in input variables to drive the models = sometimes you can leave out important factors to see what happens
Spacial heterogenity
Spatial heterogeneity is defined either as the variation in space in distribution of a point pattern, or variation of a qualitative or quantitative value of a surface pattern.
e.g Near surface air temperature change 1870-2100: IPCC AR4 2007 - Rapid economic growth, A global population that reaches 9 billion in 2050 and then gradually declines, The quick spread of new and efficient technologies ,A convergent world - income and way of life converge between regions. Extensive social and cultural interactions worldwide ,A balanced emphasis on all energy sources
With every increment of warming the changes become larger
What is Chemosynthesis
Chemosynthesis is the process by which food (glucose) is made by bacteria using chemicals as the energy source, rather than sunlight. Chemosynthesis occurs around hydrothermal vents and methane seeps in the deep sea where sunlight is absent.
What is negative engineering?
taking carbon out of the atmosphere – it’s controversial
= theres a danger of a moral hazard as people will see it as permission to not change their habbits = to stay beneath 2* we need both
What is geo-engineering?
series of technologies to intervene in the operation of the Earth system to avoid dangerous climate change
Geoengineering is the deliberate large-scale intervention in the Earth’s natural systems to counteract climate change.
Solar Radiation Management (SRM)
you attempt to reduce the amount of insolation reaching the earth -Space reflectors, Stratospheric aerosols, Cloud seeding, Cloud albedo, Surface albedo
Carbon Dioxide Removal (CDR)
reducing greenhouse gasses in the atmosphere- Carbon capture at source, Afforestation, Carbon dioxide air capture, Enhanced weathering, Ocean fertilization, Biochar
Space reflectors-
reflectors up in space that is reflecting the suns radiation back up before it hits the atmosphere – would be effective but the tech isnt read, expensive and unknown geog impacts – earth system dosent respect boundaries – could be international law implications as unexpected damage could effect elsewhere
Stratospheric Aerosols
generate clouds by creating water vapor by sticking aerosols in the atmosphere at particular elevations – increases albedo = effective , low cost compared to space reflectors, ready, but the climate impacts and governments
Atomize sea water
create small particles of sea water that helps form clouds – jot read , expensive , wouldn’t be globally effective and may effect other areas
Surface albedo changes
shiny crops – co benefits = more accessible – plants ff and albedo and can be eaten = not ready – moderately effective – but you need lota of land for this to be effective
Afforestation
planting more forests – lows cost, effective, ready but we need large areas of land
Carbon capture and storage
capture carbon and put it in cavers that have been evacuated of oil gas and water – dosent take co2 out of the atmphere but it neutralizes ffosil fuels
Silicate weathering
enhanced weathering of silicate rocks – low cost , ready effetive , no long term effects
The martin hypothesis
use iron to increase ocean activity – iron x experiments demonstrated that its getting re mineralized and therefore re circulating in the ocean so not getting rid of co2, they thought there would be a co benefit of fishing but it would lead to eutrophication and therefore killing eco systems
Carbon dioxide air capture
sucks in air and strips it from co2 and puts it underground as a solid form – what’s the energy source that drives the carbon capture ? - in ice land geo thermal energy is used for this , high cost ,low risk, effectivity , don’t need international agreements , tech is nearly ready
Ocean carbon capture
its much more concentrated and therefore quicker for getting it out of the system through chemical engineering – part of the chemical process creates hydrogen and fresh water
