Cycles Flashcards

Question

Give an example of a positive and negative feedback loop

Answer 1

The PETM (Paleocene–Eocene Thermal Maximum) The planet warmed 5-8* due to a volcanic erruption increasing in methane = oceans asidified and animals die Calcium Carbonate in the water suddenly suddenly went to zero The ocean was warming prior to this event and then suddenly we past a tipping point- gas hydrates – ice substance where methane is locked in a lattice of ice usually stable but if the temp rises is becomes unstable and dissociates meaning the methane is released Some would argue that this gas was then exhausted so no more gas was pumped into the atmosphere – there are processes that we don’t fully understand that will bring the earth back to an equilibrium at some point.

Answer 2

Biogeochemical cycles mainly refer to the movement of nutrients and other elements between biotic and abiotic factors.” The term biogeochemical is derived from “bio” meaning biosphere, “geo” meaning the geological components and “chemical” meaning the elements that move through a cycle

Answer 3

Water cycle is linked with the earths climate as is driven by energy but also creates it e.g when it changes from solid to liquid, liquid to gas e.g it requires energy (which primarily comes from the sun ) equally when water condenses from gas to liquid or liquid to solid it releases energy adding more to the cycle

Answer 4

Over long periods of time things are recycled within the earths crust- some is lost in oceanic rocks but most is returned back to the earth by the rock cycle

Answer 5

Created with basalt and gabbro (dark colored) -at spreading centers- thinner and denser(base rich and alkali, iron e.e.) than continental crust- doesn't float like continental plates it sinks back down to the mantle over a period of 200 million years. Form positive ridges as it cools it subsides Crud forming- lighter material that forms on the surface – doesn't go back down- forms bigger lumps = land= silica rich

Answer 6

low density allows it to float creating land. Earths crust is about 4 billion years old and a product of geologic recycling. -the crust in the middle is older than the outside

Answer 7

The solid outer part of the earth – includes the brittle upper part of the mantle- asthenosphere is beneath it 100km thick- considered elastic but still a solid and not liquid caused by the high pressure caused by miles of mantle and crust The brittleness of the mantle is enough to cause faults and earthquakes

Answer 8

Mass Extinction As Pangea formed, the extent of shallow water habitats declined, and land barriers inhibited cold polar waters from circulating into the tropics. This is thought to have reduced dissolved oxygen levels in the warm water habitats that remained and contributed to the 95 percent reduction of diversity in marine species.

Answer 9

over long geologic times carbon dioxide returns to the atmosphere by decomposition of limestones subducted to the Earth's deep interior, releasing carbon dioxide through gases dissolved in magmas that rise to the surface. Plate tectonics and the supercontinent cycle also play a large role in cycling carbon between the atmosphere and rock sphere.

Answer 10

continents collide to form a supercontinent, the passive margins on these continents that contain thick limestone sequences are uplifted above sea level. The tectonic uplifting of carbonate rocks causes them to be exposed to the atmosphere during continental collisions. The calcium carbonate (CaC03) then combines with atmospheric Co2, depositing it in the oceans. Thus continental collisions and times of supercontinent formation are associated with drawdown and reduction of Co2 from the atmosphere, global cooling, and sea-level changes

Answer 11

The mass of carbon stored in the limestone and organic matter reservoirs on Earth is huge, about 2,000 times greater than all the carbon presently in the atmosphere and oceans combined. Living plants contain about the same amount of carbon as that in the atmosphere, so human activities such as deforestation that change the vegetation balance on the planet may significantly change the balance between atmospheric and living organic reservoirs for the carbon, putting more Co2 in the atmosphere and altering global climate.

Answer 12

Magma may not escape the surface, could solidify- e.e. granite Rocks that come out as the solidification of magma is igneous rock Metamorphic rocks = metamorphism of other ricks = heat and pressure changes the rock

Answer 13

The supercontinent cycle describes the assembly, duration and fragmentation of the largest landmasses on Earth as a result of large-scale, long-term plate tectonic processes originating within the mantle and the crust. In the 19th century, geologists believed that as the Earth cooled and shrank, the crust underwent collapse. Therefore, land bridges for example between South America and Africa sank and gave way to the South Atlantic Ocean.

Answer 14

The himilaya – sediement being eroded and distriupted by ice Continent continent collusions – india , 40 million years ago ( been going on for 40 million years), the ocean ahead of india was subducted and then eventually collided with Asia.

Answer 15

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.

Answer 16

It affects temperature by influencing the seasonal range in solar intensity. It influences precipitation in as much as evaporation is temperature dependent.

Answer 17

Because air and currents work together to re-distribute heat. Winds blowing over the sea creates currents Winds also help evaporate water which comes as precipitation later (rain)

Answer 18

aka water moving and the heat moving with it The ocean surface is a source of atmospheric heat as the water processes circulate the heat bringing it to the top Sea ice expands upon cooling surface waters below the freezing point and this reflects more sunlight. A warming ocean gives off carbon dioxide, favoring further warming. Both of these mechanisms are "positive feedback" within the climate machine

Answer 19

the result of Earth's rotation on weather patterns and ocean currents It makes storms swirl clockwise in the Southern hemisphere and counterclockwise in the Northern Hemisphere. The Earth rotates faster at the equater than the poles

Answer 20

Earth is wider at the Equator, so to make a rotation in one 24-hour period, equatorial regions race nearly 1,600 kilometers (1,000 miles) per hour. Near the poles, Earth rotates at a sluggish 0.00008 kilometers (0.00005 miles) per hour.

Answer 21

They appear to bend to the right in the Northern Hemisphere. The Coriolis effect behaves the opposite way in the Southern Hemisphere, where currents appear to bend to the left.

Answer 22

Ozone (O3) in the upper atmosphere shields the Earth from UV radiation from the sun. Chlorofluorocarbons (CFC’s) used as refrigerants react with O3 and destroy it as a protective screen. The Montreal Protocol (1987) was 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. 1974 – 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. The interaction between the polar vortex circulation of the atmosphere and very cold polar stratospheric clouds, a chemical reaction on their surface liberated chlorine and bromine = the destruction of the ozone layer

Answer 23

“ transfer of carbon between Atm, Oceans, and Life”= ff, respiration, air sea exchange and humus in soil.

Answer 24

2(CO2)+ 3(H2O)+CaSiO3 = Ca2+ 2(HCO3-)+H2SiO4 = ions transported by rivers to the ocean where their used In oceanic production, carbonate is produced = carbonated production = cycle continues

Answer 25

dosen’t do anything to reduce the Co2 content of the atmosphere

Answer 26

= more co2 = Marine sediments on top of a oceanic plate is mostly carbon and their dragged down to the subduction zone as well.

Answer 27

warmer greenhouse conditions have dominated earths history so far (red and brown periods), there have been extended icehouse periods blue intervals) The current icehouse began ~34 million years ago with increased glaciation in Antarctica and accelerated with northern hemisphere glaciation over the past 3 million years.

Answer 28

Lower CO2 percentages, sea levels were lower= rates of carbon burial, or sequestration of organic carbon, are reduced in icehouse times, because the oceans are better aerated and the area of dysoxic restricted basins is smaller.

Answer 29

“ regulation of the transfer of carbon to and from rocks” Over millions of years, carbon moves from rocks and the earth through complex feedback loops, nutrient cycles, atmospheric processes, carbon burial and climate.

Answer 30

The fluxes in carbon since the phanerozoic era (550 million years ago) shows how the burial of organic matter leads to the formation of fossil fuels and atmospheric composition,

Answer 31

consists of the ocean, atmosphere, biosphere and soils. The long-term carbon cycle is the main controller of the concentration of atmospheric carbon dioxide and (along with the sulphur cycle) atmospheric oxygen over a geological timescale

Answer 32

terrigenous material transported within a matrix of ice and deposited in marine or lake sediments when the ice matrix melts- black seems running through an ice Berg = sediment = ice melts and the sediment is released to the sea bed. = calcium carbonate made up off shells- rock debris and mineral fragment w biological –faces of major ice berg distribution

Answer 33

The long-term climate change during the Cenozoic corresponds at first order to a cooling, which drove Earth from a state without ice caps to one with two poles glaciated [Fischer, 1981]

Answer 34

are all around 280-300 ppm(before the industrial revolution) 25,000 years ago a value of 180ppm. Their cycles and are repetitive Glacial and interglacial cycles within the icehouse faze = Seasonal component that is effected = keeling curve = ff = antartic is a good place to messure as the season dosen’t effect it that much

Answer 35

The exchange of of gas between the atmosphere and ocean e.g solar heating leads to water vaperation ( is responsible for 90% of this) which in turn goes to the atmosphere cools and falls as rain, ending up back in the ocean. The cycles that happen within the earths system e.g the rock cycle or the carbon cycle

Answer 36

Plant exchange with the atmosphere creating oxygen. Ff Resbiradaeth – we take in oxygen and create co2 for plants = repeat

Answer 37

The “Great Oxidation” event, 2.4 Ba, resulted from the evolution of photosynthesizing cyanobacteria. This is represented in the geological record by the first appearance of red beds caused by the oxidation of iron-rich minerals (rusting)

Answer 38

anaerobic meaning the iron minerals reduce and they loose their colors

Answer 39

no o2 = sediment is reduced so their also grey, white or back e.g the white cliffs of dover.

Answer 40

it robs electrons from other elements and compounds in the process of oxidation (the opposite is reduction).

Answer 41

It breaks down the organic carbon produced by photosynthesis in animals, fungi, microbes and by photosynthesizing organisms to fuel their growth. Some of the oxygen is bound in the rocks = not used = not important Most o comes from ff

Answer 42

due to its high affinity for electrons. However, some organisms have evolved to use other final electron acceptors, and as such, can perform respiration without oxygen.

Answer 43

No significant gas faze Very rare element Comes from minerals in rocks Apatit- has lots of phosphorus A bit escapes the recycling and accumulates in the ocean Phosphorus enters the Earth system through weathering of rocks containing the mineral apatite. Fungi dissolve apatite and convert phosphorus into liquid phase phosphate where it is available to land plants. Some liquid phosphate reaches the ocean via the hydrological cycle where it is available to marine primary producers. It is readily recycled in the surface ocean, but some sinks into deep waters (AABW, NADW) fuelling productivity where these deep waters upwell back to the surface.

Answer 44

weathered out –becomes liquid- delivered to the ocean and used for production , gets buried and over time through tectonics gets recycled to the mineral faze

Answer 45

Apatit- has lots of phosphorus- fungus can dissolve t and create phosphate and becomes available to plants

Answer 46

A bit escapes the recycling and accumulates in the ocean- the longer the circulation the more phosphate collects so when it upwells the water is very nutrient so then the water fuels primary production

Answer 47

Most abundant as gas

Answer 48

the atmosphere but the molecules are very strongly bonded making them largely unavailable.

Answer 49

Splitting of nitrogen – nitrogen fixation – is achieved by plants with a symbiotic relationship with nitrogen fixing bacteria (in, for instance, root nodules) and, in the ocean, by cyanobacteria. This takes a lot of energy, fuelled by sunlight.

Answer 50

Nitrogen is fixed into ammonium, NH4+, which yields energy when reacted with oxygen. Nitrifying bacteria live off this energy, converting ammonium to nitrite (NO2-) and then nitrate (NO3-). This is the major reservoir of biologically available nitrogen (assimilation). Nitrate can be used to oxidise organic matter, yielding energy, and converting nitrate back into nitrogen gas in a process called denitrification.

Answer 51

Nitrogen fixation is achieved by plants that have a symbiotic relationship with plants = needs lots of energy and fueled by sunlight

Answer 52

Photosynthesizers take up nitrate, and some ammonium, and convert it into organic matter. This is then recovered by decomposers, making it available again as a nutrient. Like phosphate, nitrate is readily recycled in the surface ocean but some sinks into the deep ocean to fuel productivity in upwelling regions.

Answer 53

This tilting leads to a variation of solar energy that changes with latitude. This causes a seasonal variation in the intensity of sunlight reaching the surface and the number of hours of daylight. The variation in intensity results because the angle at which the sun’s rays hit the Earth changes with time of year= aka the tilt is the cause of seasons

Answer 54

effect the carbon cycle and biosphere = more sunlight = more biosphere = less co2 in the atmosphere

Answer 55

Obliquity is the tilt of Earth’s axis relative to the plane of the ecliptic. This varies over 41,000 years from 22.1° to 24.5 °. This influences seasons, solstices, length of day and the angle of incoming radiation. A high angle of tilt increases the seasonal contrast, most effectively at high latitudes (e.g., winters in both hemispheres will be colder and summers hotter as obliquity increases). Obliquity thus causes amplification/suppression of seasons, especially at high latitudes. Increases the seasonal contrast at the higher angle , winters in both hemispheres would be colder in both hemispheres 2 low frequency cycles- one is more oblique than the other – that happned once every 400,000 years

Answer 56

They all combine through time to influene the amount of sun Eccetion is moderated by axial precession

Answer 57

If it’s cold In the summer that’s when there’s a change= that effect the albedo all year The Milankovitch cycles drive all the other cycles which is caused by the gravitational pull

Answer 58

While gravitational attractive forces vary inversely to the square of the distance between the objects, tidal generating forces vary inversely as the cube of the distance of the tide generating object. Therefore with tidal generating forces, distance is a more highly weighted variable than it is in the gravitational attractive force.

Answer 59

Tidal resonance occurs when one of the tidal constituents is excited by the morphology of the coast/bathymetry. It is most pronounced when the continental shelf is ~0.25 the wavelength of the tidal wave. This causes an incident tidal wave to be reinforced by reflections between the coast and the shelf edge. The most extreme manifestation of tidal resonance is the tidal bore, shown here in the Gironde Estuary SW France.

Answer 60

in the oceans has not been constant through geological time. During the LGM total dissipation was ~4.7 TW, at present it is ~3.5 TW. 20,000-25,000 years ago

Answer 61

Earth had been spinning so fast that some material broke away and began to orbit the planet. What is most widely accepted today is the giant-impact theory. It proposes that the Moon formed during a collision between the Earth and another small planet, about the size of Mars.

Answer 62

Thermohaline circulation begins in the Earth's polar regions. When ocean water in these areas gets very cold, sea ice forms. The surrounding seawater gets saltier, increases in density and sinks. Winds drive ocean currents in the upper 100 meters of the ocean's surface. The global thermohaline circulation (Meridional Overturning Circulation): driven by wind stress and tidal mixing exploiting the potential energy of density contrasts as a function of temperature and salt content

Answer 63

Bottom waters are formed in the high latitudes of both hemispheres. In the Northern Hemisphere the densest waters are formed in the North Atlantic Ocean, in the Labrador and Greenland sea

Answer 64

EVAPORATION. CONDENSATION. PRECIPITATION. INTERCEPTION. INFILTRATION. PERCOLATION. TRANSPIRATION.

Answer 65

The hydrologic cycle involves the continuous circulation of water in the Earth-Atmosphere system. At its core, the water cycle is the motion of the water from the ground to the atmosphere and back again

Answer 66

Although the total amount of water within the cycle remains essentially constant, its distribution among the various processes is continually changing.

Answer 67

The cryosphere is the frozen water part of the Earth system. This includes frozen parts of the ocean, such as waters surrounding Antarctica and the Arctic. There are places on Earth that are so cold that water is frozen solid temperatures below 0°C

Answer 68

The largest parts of the cryosphere, the continental ice sheets found in Greenland and Antarctica, as well as ice caps, glaciers, and areas of snow and permafrost. When continental ice flows out from land and to the sea surface, we get shelf ice.

Answer 69

Snow and ice reflect heat from the sun, helping to regulate our planet’s temperature. Because polar regions are some of the most sensitive to climate shifts, the cryosphere may be one of the first places where scientists are able to identify global changes in climate.

Answer 70

The biosphere is made up of the parts of Earth where life exists. The biosphere extends from the deepest root systems of trees, to the dark environment of ocean trenches, to lush rainforests and high mountaintops. Scientists describe Earth in terms of spheres.

Answer 71

where there isn't any radtionon due to changes in the magnetic field in the sun itself.

Answer 72

Sunspots are temporary features visible on the surface of the sun caused by slightly lower temperatures reflecting concentrations of magnetic field flux inhibiting convection. But around the sunspots are brighter areas that represent solar flares that are responsible for altering the total radiation emitted by the sun.

Answer 73

11 years peak to peak Lots of sun spots mean there is lots of radiation

Answer 74

Glaciation of Antarctica after 35 Ma BP 40 million years ago Antarctica was a warm ish place – a forest similar to the one in south America today Each glaciation got bigger and bigger until about a million years ago –it filled the entire continent

Answer 75

The nutrient cycle is a system where energy and matter are transferred between living organisms and non-living parts of the environment. This occurs as animals and plants consume nutrients found in the soil, and these nutrients are then released back into the environment via death and decomposition.

Answer 76

Because of the density difference between surface water and the deep sea across most of the ocean, ocean circulation can only very slowly reintroduce dissolved nutrients to the euphotic zone. By driving nutrients out of the sunlit, buoyant surface waters, ocean productivity effectively limits itself.

Answer 77

ocean acidification which is defined as a decrease in ocean pH caused by a reduction in carbonate ion availability The ocean and atmosphere try to keep an equlirbium of carbon in the ocean and atmosphere Seawater ph used to be between 8-9 in the late 1800, by 2100 it’s be below 8

Answer 78

Dissolved CO2 which reacts with seawater to form carbonic acid, H2CO3 (= ocean acidification) Bicarbonate, HCO3

Answer 79

cant make them due to a lack of carbonate in the water due to the chemical reactions

Answer 80

Ocean acidification inhibits the ability of calcifying organisms to grow their shells and may even cause dissolution of shells Dissolution of gastropod molecules shell when placed in more acidic seawater over a period of 45 days- the solution of the shell matrix – an Asid alkali reaction Inorganic carbon is locked in the shell of a bio

Answer 81

Ocean acidification causes the carbonate compensation depth (CCD) in the deep ocean to shoal (= get shallower) causing the dissolution of carbonate deposits on the seabed Ocean acidification causes the carbonate compensation depth (CCD) in the deep ocean to shoal (= get shallower) causing the dissolution of carbonate deposits on the seabed More carbonate at the top of the sea bed but as the depth increasing theres less carbonate until it’s dissolved completely The CCD – where there's no calcium carbonate – is increasing as carbon levels increase The burial of calcium carbonate is crucial to the carbon cycle but ocean acidification is stopping this process

Answer 82

= stimulates primary consumption = zoo plankton = takes oxygen + the new plant matter is dying and breaking down = taking more oxygen = eutrophic systems = the system will become basically anaerobic It Is a natural process however we’ve interviened to an extreme extent Ffen – an alkali bog – a base rich ffen – live in water logged conditions Acid bog – nutrient poor – neutrophic ffen Excessive run off of feritilizer gets rushed off and into river system = affecting these systems and artifically enhancing productivity

Answer 83

Eutrophication is enhanced through the runoff of detergents, agricultural fertilisers and/or sewage into natural systems. Key indicators of cultural eutrophication are blooms of phytoplankton and cyanobacteria. These stimulate secondary consumption and respiration causing drawdown of oxygen levels. Can effect the ocean as well – especially where theres outflow of fresh water systems that are nutrient enhances= a major problem

Answer 84

Carbon storage and exchange For example, in the food chain, plants move carbon from the atmosphere into the biosphere through photosynthesis. They use energy from the sun to chemically combine carbon dioxide with hydrogen and oxygen from water to create sugar molecules.1