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Questions tagged [biogeochemistry]

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2
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0answers
151 views

Where does molecular hydrogen in the atmosphere come from?

This figure from Wikipedia's Atmosphere of Earth shows a hydrogen fraction of 0.000055 percent by volume. Question: Where does molecular hydrogen in the atmosphere come from? Does this come directly ...
1
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0answers
21 views

Has biology's influence in CO2/Phanerozoic variations been decisive?

I must say I always as geologist have explained myself CO2 changes at Earth's History in terms of Wilson Cycle. And I always thought biosphere is adapted to geology. But from two questions I link at ...
2
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1answer
72 views

How much net carbon can coral sequester?

So I am wondering how much carbon any given coral can sequester given that carbon dioxide dissolves in water and forms carbonic acid, and coral uses that carbonic acid in their own calcification ...
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0answers
18 views

Do living things have a magnetic field capable of any level of solar protection?

I understand how anything with an electrical current have a magnetic field including living things. Would a densely populated rain forest or jungle have enough combined magnetic field among the living ...
2
votes
1answer
138 views

How quickly can coral fossilize?

On a trip to Honduras a few years ago I visited one of the islands off its north coast with a friend and went to a section of it mostly with nothing but residences which looked far less visited by ...
8
votes
4answers
337 views

Before the Great Oxygenation Event, where was the oxygen?

Today, the oxygen in the atmosphere is about 1018 kg. The estimated carbon biomass of the earth is about 4×1015. Less than 0.5%. Estimated fossil fuels are around 5 times as much as existing carbon ...
3
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0answers
50 views

Sulfate reduction

I read a document in which the authors stated "Sulfate and sulfide ( bisulfide and dihydrogen sulfide) both exist within a system just in varying proportions, and aqueous speciation is dependent on Eh/...
9
votes
1answer
546 views

Is it true that “All life on earth gets its energy from the sun”? How much biomass is not derived from photosynthesis?

In helping my son with his college biology I ran across some statements that I think are wrong according to updated data. The copyright is 2017 so it is supposed to reflect the most current knowledge....
5
votes
2answers
124 views

How would a world entirely covered in oceans get the nutrients to support life?

On earth nutrients flow from the land to the ocean. Life on oceans need those nutrients to trive. I was trying to think how an ocean world might support life if there was no land to provide the ...
2
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0answers
32 views

Formation of dolomite

What are the kinetic barriers to dolomite precipitation? Does it precipitate out in solution as quickly as Calcite does?
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0answers
77 views

Formation of minerals from decomposition of soil

I was wondering if aerobic decomposition of organic rich soils, also rich in calcium and sulfur, can result in the precipitation of gypsum. My thinking is the decomposition would release the ...
0
votes
2answers
52 views

calculation monocationic elements

How to calculate of the number of monocationic millimoles? If I have concentrations of: $SiO_2$, $TiO_2$, $K_2O$, $MgO$, $MnO$, $Na_2O$, etc. How can I get $Na^+$, $Mg^{2+}$, $Mn^{2+}$ ..? This is ...
7
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2answers
100 views

Will photosynthesis based carbon sequestration always be more efficient than other chemical means - in terms of rate?

There seem to be many ideas for carbon sequestration. The problem with anything electrochemical, is that unless it is solar-based, you're putting carbon into the atmosphere at probably a great rate ...
6
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1answer
168 views

Abiogenesis: Formation of Lipids from Montmorillonite

I have been really interested in scientific hypotheses regarding abiogenesis, particularly the lipid-world hypothesis. However, I could not find information on the chemical pathway that leads to the ...
6
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0answers
45 views

Effect of snow on BVOC emmisions of plants/trees

Plants re-emit a substantial fraction of their assimilated carbon into the atmosphere as Biogenic Volatile Organic Compounds (BVOCs) that affect the chemical and physical properties of the atmosphere. ...
6
votes
1answer
253 views

Nitrogen cycle semantics; nitrification/nitrogen fixation

Is 'nitrification' and 'nitrogen fixation' used interchangeably to describe biological reduction of $\ce{N2}$ gas to $\ce{NH3}$? I know $\ce{NH4} \to \ce{NO3}$ is called nitrification too.
4
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2answers
621 views

Can you measure BOD/COD real time using any sensor?

There is a requirement to measure BOD/COD in a wastewater treatment plant in real time. Is it possible? And if so are there any sensors available in the market for it?
3
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0answers
42 views

A question about the disruption of global geochemical cycle in anthropocene

We often only hear of problems with the carbon, nitrogen & water cycles etc. I would like to know if there have been any observed problems with other cycles - for example, the iron cycle, ...
1
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0answers
36 views

How do tree roots mitigate pollution in general? Diagram preferred [closed]

I understand that tree roots help mitigate pollution in a variety of ways, and I imagine to greatly varying extents. I get the general idea (I'll describe my thoughts below) but would like ...
3
votes
1answer
252 views

Mixing equation for confluence of two rivers

How can I calculate the final concentration of two ions in a river after the confluence of two rivers? River 1 flows at $\small\sf{7000\ L/s}$, contains $\small\sf{500\ mg/L\ Mg,\ 1.1\ g/L\ Ca}$ ...
3
votes
2answers
136 views

What are the natural causes for methane formation?

Natural gas is mostly made of methane ($\ce{CH4}$). Methane can be produced as a result of microbes eating organic matter. But can it also be naturally formed without any assistance from organic ...
3
votes
2answers
2k views

What is the meaning of the units Mg C?

I am reading an article on deforestation entitled Tropical Deforestation and Carbon Emissions from PADDD. Part of the article reads: If future deforestation rates follow recent trends, PADDDed ...
3
votes
1answer
330 views

The free oxygen (O$_2$) in the atmosphere is largely a result of what process?

Does it come from a)atmospheric lightning and ozone dissociation. b)meteorite impacts early in the earth's geological history. c)Paleozoic volcanic activity. d)photosynthetic processes. e)...
3
votes
1answer
464 views

Why don't all living beings die at night due to lack of oxygen?

During the day plants photosynthesize and give out oxygen through stomata. But during the night, when half of the planet is dark, half of the earth's trees/plants consumes oxygen to survive. At that ...
9
votes
1answer
650 views

where are the thickest limestone layers on earth ? (CaCO3)

What is the maximum thickness of limestone layers on earth? (Limestone or any other biochemical sedimentary rocks, for example chalk or coral reefs.)
9
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3answers
738 views

Are there sufficient quantities of limestone to dump in the ocean to reverse acidification?

This question asked: What is the evidence it is feasible to reverse ocean acidification by adding large quantities of a base (bicarb soda)? The result was: Danny Harvey of the University of ...
4
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2answers
10k views

What is the difference between a carbon sink and a carbon reservoir?

I am trying to figure out the difference between a carbon sink and a carbon reservoir. The definition for a carbon sink from wikipedia is that “carbon sink is a natural or artificial reservoir that ...
4
votes
1answer
126 views

Timescale of the biological pump?

I'm tying to find any clue about the timescale of the biological pump. That the carbon is recycled to the surface ca. 1,000 years is clear but the timescale of the biological pump seems hard to find. ...
16
votes
2answers
1k views

How is the equilibrium of 21% oxygen in Earth's atmosphere established?

The atmosphere is 21% oxygen. I assume that there must be an equilibrium between processes that produce oxygen (e.g. photosynthesis) and those that consume oxygen (e.g. aerobic respiration). Moreover,...
7
votes
2answers
163 views

Recreating the rock cycle

I want to recreate the rock cycle using some item that can behave as a rock. The purpose of this is to get a point across to my students about how really there is a reason why the rock cycle is called ...
18
votes
4answers
1k views

Why does Earth have abundant oxygen in the atmosphere?

Because of photosynthesis, obviously. But then it's not actually that obvious after all, because photosynthesis is mostly balanced by respiration. We can summarise the processes of photosynthesis ...
14
votes
3answers
2k views

How much of earth's molecular oxygen in the atmosphere is due to plants?

I know plants form a critical part of the earth's biosphere, including molecular oxygen production. Molecular oxygen makes up ~20% of our atmosphere. How much of the earth's molecular oxygen in the ...
12
votes
3answers
325 views

What is the age of the earliest traces of life on Earth?

In the article Oldest rocks, earliest life, heaviest impacts, and the Hadean–Archaean transition (Moorbath, 2005), the author states (based on previous referenced research) that the $\ce{^13C}$ ...
14
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1answer
828 views

How is carbon distributed among the atmosphere, the oceans, the biomass and the unburnt fossil fuels?

In relation to my other question about carbon cycle and climate change, i would like to know some estimates of the carbon distribution among the atmosphere, the oceans, the biomass and the unburnt ...
18
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1answer
371 views

What is the importance of mixing caused by outgassing in the ocean?

I have been asked the following question for which I have no clear answer: What is the relative importance on mixing of the vertical flow of gases (e.g., Oxygen produced by photosynthesis, CO2 ...
22
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2answers
1k views

Peak phosphorus - what are the sinks?

The minable phosphorus reserves are limited. Where is the mined phosphoprus landing, what are the global phosphorus sinks? I would assume that most phosphorus is used for fertilizer and ultimately ...