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Offline Richard Bennett

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New theory for dinosaur extinction
« on: 16/11/2007 23:48:24 »
Ok this is such a simple theory why has no one else come up with it?
I'm not a scientist and Ive not seen this anywhere else yet. Thought it up a couple of years ago and done nothing about it until I found this site.

Working on the carbon cycle i will try to make this short and simple!
Basically the carbon cycle is a cycle, but not a balanced cycle. It is an unbalance cycle, regulated by co2 and plant/aquatic life, changing from an ice age to a global explosion of life. And it is life itself which triggers these changes and explosion/extinctions across the planet. Interested?
Read on its simple logic!


I am starting this cycle where there is a high amount of co2 in the atmosphere after an ice age. With this increasing level of co2, temperatures rise. With this temperature rise evaporation precipitation and relative humidity increase respectively. This is a cycle in the planet where life begins to proliferate, the ice caps melt and the tropical band around the equator spreads. Life in the oceans and on land is expanding and expanding.
Now the cycle is unbalanced, so carbon is slowly laid down in the earth as peat, a common carbon store found today. In Indonesia there are bogs where the peat level is estimated to be 20m deep. Formed over the last 20,000 years. There have been estimates that 50 billion tonnes of co2 are locked up there and are a major worry to global warming. They drain them for palm oil plantation and it starts to decompose with this co2 entering the atmosphere. Or burns as in 1997, a dry year, Indonesian peat fires contributed an estimated extra 40% co2 to the global emissions that year. Releasing an estimated one billion tones of co2 in the 1997 Indonesian fires. Digressing
So peat is building up around the world. We know this is a regular cycle in the history of the earth. Coal and oil finds around the world, older peat deposits trapped in the earth.
As the average temperatures increase so does oceanic evaporation and precipitation and relative humidity. As this increases we get more growth across the planet and more rain means more swamps. Peat builds up faster and faster, in ever increasing areas across the planet. A cycle causing atmospheric levels of co2 to slowly decrease. This cycle is speeding up very slowly.
There becomes a cut off point where the co2 in the atmosphere is so low that plant growth slows right down and the cycle reverse. The planet slowly starts to cool down as more heat radiates out into outerspace than is gained through the day. The average temperatures drop very slowly. It would drop a lot faster but does not. This is due to the thermal mass of the earth and the oceans slowly give up the heat stored in them over the last 1000s of years. Keeping the night temperatures from plumeting stalling an extinction event.
When the the aceans and earth give up a critical amount of heat stored in them, the cooling cycle all of a sudden speeds up. Average temperatures slowly begin to plummet and
this is where the planet enters an extinction phase
An ice age truly begins, where life mass across the planet begins to slowly decrease in the oceans and on land. This time there a total reversal of trends
Finally with this massive reduction of life on earth and average temperatures so correspondingly evaporation and precipitation are massively reduced. And co2 begins to once again build up in the atmosphere. There are probably numerous forces contributing to the global increase of co2 in an ice age. Most possibly the biggest contributor is the decrease in rainfall and reduction in sea level, means the swamps begin to dry up and billions of tons of peat across the planet begin to decompose releasing their co2 slowly back into the atmosphere, especially in equatorial regions.
 This is an exact reversal of the warming up phase the thermal mass of the oceans and land are storing the cold. So co2 builds up enough to trap more heart in the atmosphere than is radiated out. But it has little effect as the stored cold in the earth and oceans counter it until it hits a turnaround point. Then average temperatures globally begin to soar, relatively to the previous hundreds or thousands of years.

So it is my theory that an unbalanced carbon cycle, initiates an iceage and its reverse, which is a planetary explosion of life. And an extinction phase and a species explosion phase are part of this cycle on the earth.

This is my original theory posted here first. Thought up 2-3 years ago and slowly evolving. Its not a far out theory just seems like logic. Need some scientists to do some environmental modeling of this theory to help prove it. Any takers? A lot of this kind of work may already be done under co2 and global warming.

What do you think? Bullocks or a sure thing???????????

Got a feeling that 100s millions of years ago this cycle may have been more extreme but slowly more and more carbon got locked up inside the earth (coal oil)and the cycle has been moving to less extremes. Now we are releasing a huge percentage of that locked up co2, we will probably be able in 200 years to grow crops in Antarctica as the earth warms up before the turn around. If there is one because of our deforestation and draining of swamps will reduce or stop the locking up of co2 in peat.

Regards Richard Bennett


 

another_someone

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New theory for dinosaur extinction
« Reply #1 on: 17/11/2007 01:03:44 »
You have to start by defining what you mean by an ice age.  Technically, we are still in an ice age (insofar as we still have polar ice caps).  In the time of the dinosaurs, there were no polar ice caps, but this was in part because there was no land mass sitting over the south pole.

The most extreme cases of ice ages are what is known as 'snowball earth', where the entire surface of the Earth is covered in ice, and no life can exist (except maybe near volcanic vents, particularly on the ocean floor).

http://en.wikipedia.org/wiki/Snowball_Earth
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he Snowball Earth hypothesis as it currently stands[2] proposes that the Earth was entirely covered by ice in part of the Cryogenian period of the Proterozoic eon, and perhaps at other times in the history of Earth. It was developed to explain sedimentary glacial deposits at tropical latitudes during the Cryogenian period (850 to 630 million years ago) and other enigmatic features of the Cryogenian geological record. After the last big freeze ended, multicellular evolution began to accelerate. Snowball Earth remains controversial, and is contested by various scientists who dispute the geophysical feasibility of a completely frozen ocean, or the geological evidence on which the hypothesis is based.

The beginning of a Snowball Earth event could be facilitated by an equatorial continental distribution, which allows rapid, unchecked weathering of continental rocks, absorbing vast quantities of carbon dioxide from the atmosphere. The depletion of this greenhouse gas causes ice accumulation, which further cools the planet by reflecting solar energy back to space. The runaway system would lead a new ice-covered equilibrium with equatorial temperatures similar to modern-day Antarctica.

To break out of the frozen condition, huge quantities of greenhouse gases such as carbon dioxide and methane, emitted primarily by volcanic activity, would have to accumulate over millions of years. Once melting began, however, it would be quick, perhaps only 1000 years.

Weathering of glacial sediments, by reacting with carbon dioxide, and fertilising oceanic photosynthesisers, may have eventually drawn down enough of the greenhouse gas to instigate another Snowball Earth.

Sedimentary features usually formed by glaciers, found in what may have been equatorial locations at the time of deposition, have been taken as evidence implying global ice cover. Many other features of the sedimentary record are easily explained by extensive glacial cover. Geochemical evidence from rocks associated with low-latitude glacial deposits have been interpreted to show a crash in oceanic life during the glacial times, which is consistent with a freezing of the surface oceans.

Whilst the presence of glaciers is not disputed, the idea that the entire planet was covered in ice is more contentious, leading some scientists to prefer a "slushball" to a "snowball". In a slushball scenario a band of ice-free, or ice-thin, waters remains around the equator, allowing for a continued hydrologic cycle. This appeals to scientists who believe that certain features of the sedimentary record can only be explained by rapidly moving ice, which would require somewhere ice free to move to, or that observed sedimentary structures could only form below open water. Attempts to construct computer models of a Snowball Earth have also struggled to accommodate global ice cover, without fundamental changes in the laws and constants which govern the planet. Attempts have been made to explain equatorial ice-deposits by claiming Earth's spin axis or magnetic field changed dramatically. Recent research using observed geochemical cyclicity in clastic rocks suggests that the "Snowball" periods were punctuated by warm spells, similar to ice age cycle in recent Earth history.

Snowball Earth has profound implications on the history of life on Earth. While many refugia have been postulated, global ice cover would certainly have ravaged ecosystems dependent on sunlight. The melting of the ice may have presented many new opportunities for diversification, and may indeed have driven the rapid evolution which took place directly at the end of the Cryogenian period.

The carbon dioxide levels necessary to unfreeze the Earth have been estimated as being 350 times what they are today, about 13% of the atmosphere. Since the Earth was almost completely covered with ice, carbon dioxide could not be withdrawn from the atmosphere by the weathering of siliceous rocks. Over 4-30 million years, enough CO2 and methane, mainly emitted by volcanoes, would accumulate to finally cause enough greenhouse effect to make surface ice melt in the tropics until a band of ice-free land and water developed; this would be darker than the ice, and thus absorb more energy from the sun - initiating a "positive feedback".

All of this would be long before the dinosaurs roamed the Earth.

http://en.wikipedia.org/wiki/Ice_age
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The present ice age began 40 million years ago with the growth of an ice sheet in Antarctica. It intensified during the late Pliocene, around 3 million years ago, with the spread of ice sheets in the Northern Hemisphere, and has continued in the Pleistocene. Since then, the world has seen cycles of glaciation with ice sheets advancing and retreating on 40,000- and 100,000-year time scales. The most recent glacial period ended about ten thousand years ago.

In other words, the present ice age started about 25 million years after what is the normally considered the extinction date for for the dinosaurs.

http://en.wikipedia.org/wiki/Paleocene#Climate
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The early Paleocene was slightly cooler than the preceding Cretaceous, though temperatures rose again late in the epoch. The climate was warm and humid world-wide, with subtropical vegetation growing in Greenland and Patagonia. The poles were cool and temperate; North America, Europe, Australia and southern South America were warm and temperate; equatorial areas had tropical climates; and north and south of the equatorial areas, climates were hot and arid.

In other words, (if I interpret the above correctly) it suggests that cooling did start after the extinction of the dinosaurs, but it took about 25 million years to turn into an ice age, which has continued until the present day.
 

Offline Richard Bennett

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New theory for dinosaur extinction
« Reply #2 on: 18/11/2007 11:11:14 »
So then my theory may not be a new theory for the extinction of the dinosaurs. But possibly the cause the fluctuations in the current Ice age. Ultimately you need to consider how many hundreds or thousands of billions of tons of co2 have been locked up in peat in the last 20,000 years across the planet. does this cause the planet to cool and ice caps to expand. Then if evaporation is reduced because of a reduction of average global teperatures, reduced precipitation does this peat dry out and begin to decompose entering the atmoshpere again.

Is the carbon cycle balanced? or fluctuating as mentioned above?

 

another_someone

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New theory for dinosaur extinction
« Reply #3 on: 18/11/2007 21:11:00 »
Peat is only one of many stores of carbon on the planet.

Methyl hydrates are another store, and there has in the past been speculation as to whether this might cause cyclical climate changes.

Carbonate rocks (such as limestone) are another store of carbon, although I have not heard theories about how this might be recycled into the atmosphere.  And don't forget carbon locked up in subterranean coal and oil deposits.

I would doubt (although maybe someone might correct me) that peat bogs would release their carbon simply by decomposition, although they certainly can, and do, release carbon when they catch light (whether by human action, or by natural processes), and drying out would increase the likelihood of their catching fire, as well as possibly allowing their being recycled through biological action.

http://en.wikipedia.org/wiki/Peat#Formation
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Peat forms when plant material, usually in marshy areas, is inhibited from decaying fully by acidic and anaerobic conditions. It is composed mainly of peat moss or sphagnum, but may also include other marshland vegetation: trees, grasses, fungi, as well as other types of organic remains, such as insects, and animal corpses. Under certain conditions, the decomposition of the latter (in the absence of oxygen) is inhibited, and archaeologists often take advantage of this.

Peat layer growth and the degree of decomposition (or humification) depends principally on its composition and on the degree of waterlogging. Peat formed in very wet conditions will grow considerably faster, and be less decomposed, than that in drier places. This allows climatologists to use peat as an indicator of climatic change. The composition of peat can also be used to reconstruct ancient ecologies by examining the types and quantities of its organic elements.

Under the right conditions, peat is the earliest stage in the formation of coal. Most modern peat bogs formed in high latitudes after the retreat of the glaciers at the end of the last ice age some 9,000 years ago. They usually grow slowly, at the rate of about a millimetre per year.

The peat in the world's peatlands has been forming for 360 million years and contains 550 Gt of carbon.

So, yes, peat does contain a lot of carbon (550Gt), but compare it to:

http://en.wikipedia.org/wiki/Methane_hydrate#Reservoir_size
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The size of the oceanic methane clathrate reservoir is poorly known, and estimates of its size have decreased by roughly an order of magnitude per decade since it was first recognized that clathrates could exist in the oceans during the 1960s and 70s. The highest estimates (e.g. 31018 m) were based on the assumption that fully dense clathrates could litter the entire floor of the deep ocean. However, improvements in our understanding of clathrate chemistry and sedimentology have revealed that hydrates only form in a narrow range of depths (continental shelves), only at some locations in the range of depths where they could occur (10-30% of the GHSZ), and typically are found at low concentrations (0.9-1.5% by volume) at sites where they do occur. Recent estimates constrained by direct sampling suggest the global inventory lies between 11015 and 51015 m (1 quadrillion to 5 quadrillion).[11] This estimate, corresponding to 500-2500 gigatonnes carbon (Gt C), is smaller than the 5000 Gt C estimated for all other fossil fuel reserves but substantially larger than the ~230 Gt C estimated for other natural gas sources. The permafrost reservoir has been estimated at about 400 Gt C in the Arctic, but no estimates have been made of possible Antarctic reservoirs. These are large amounts. For comparison the total carbon in the atmosphere is around 700 gigatons.

These modern estimates are notably smaller than the 10,000 to 11,000 Gt C (21016 m) proposed by previous workers as a motivation considering clathrates as a fossil fuel resource (MacDonald 1990, Kvenvolden 1998). Lower abundances of clathrates do not rule out their economic potential, but a lower total volume and apparently low concentration at most sites does suggests that only a limited percentage of clathrates deposits may provide an economically viable resource.

http://en.wikipedia.org/wiki/Methane_hydrate#Methane_clathrates_and_climate_change
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Methane is a powerful greenhouse gas which, despite its atmospheric lifetime of around 12 years, nonetheless has a global warming potential of 62 over 20 years and 21 over 100 years (IPCC, 1996; Berner and Berner, 1996; vanLoon and Duffy, 2000). The sudden release of large amounts of natural gas from methane clathrate deposits has been hypothesized as a cause of past and possibly future climate changes. Events possibly linked in this way are the Permian-Triassic extinction event, the Paleocene-Eocene Thermal Maximum.

I am not suggesting that methane hydrates are a better theory that yours, only that there are as many different theories as their are sources of carbon, and the reality is that it is unlikely that any one can provide a simple explanation for climate change (for one thing, if climate change were that simple, one would expect fairly regular cycles, and the past cycles are very irregular, thus indicating that maybe more than one factor is in play - whether any of the carbon cycle theories form part of that complexity I don't think has been ascertained).
 

Offline losguy

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New theory for dinosaur extinction
« Reply #4 on: 19/12/2008 21:36:41 »
I was watching a program on television called Time Warp, a great visual oriented program that slows down different events with a high speed camera. Last night they were photographing a drop of water falling into a pan of water. The water drop carves out a depression, and then the cornet comes up and then the pillar of water and finally the concentric rings emanating from the center of the event. This is also the basics of the Chixalub impact. Time Warp also did other demonstrations and one was dropping a drop of water into very shallow water. Everything was the same as the first demonstration, until the pillar of water raise from the center which was not much higher than the coronet and then the concentric rings occurred. The Scientist that was assisting the demonstration team also had a high speed camera and had been experimenting with the drops of water. He made the statement that when the water was shallow you would get the depression being carved out and the cornet but because of the shallowness of the water the pillar of water was never much higher than the coronet. Without the tall column of water and debris raising up from the Chixalub event there would not be the world wide firestorm that would have burned up everything (there has been no world wide charcoal layer associated with the KT boundary or the Chixalub Impact Event) as well as the acid rain which would have killed all the frog species that have come survived the extinction event. The layer of iridium could have come from a portion of the asteroid being burned off as it blasted through the atmosphere (as well as from the burning up of sucker asteroids moving along with the main asteroid), wind patterns would have spread much of the dust, plus from the actual impact. A group of small sucker asteroids following the main asteroid might also account for the irregular distribution of iridium as each of their trajectories might have differed. One must also remember that with all the plate tectonics, weather, erosion, volcanism, and other large natural disasters (including seas being created and destroyed) the iridium layers and spherules may have been displaced which can account for any discrepancies in the dating and the closeness of the continents would have allowed the dispersion to look larger than it would if looking at the present continent arrangement.
The Chixalub impact was not in the same environment that is always displayed when they do an animation of the Chixalub event. The Continents had not really separated very much and the sea that the Chixalub asteroid fell into was a shallow continental shelf sea in the far west of the continents. The Chixalub impact is actually on continental shelf and possibly did not even disturb the Methane Hydride layers. Maybe the Chixalub event was not the whole cause of the dino extinction or even a major effect at all.
If the scenario that is put forth where the Impact was in deep sea bed, which caused the Carbonate Layers to heat turning them into Carbon Dioxide (Which is heavier than air) which circled the earth and killed only the Dinosaurs and a few other plants, and some of the fish and animals I think is a little off base. This is like expecting the extinction event to pick and choose who will live and who will die. If we look at the Lakes in Africa, that released Carbon Dioxide and killed every animal in the area above and below ground, then the Chixalub Impact Event would have killed everything but plant and fish.
    According to paleontologist the Dinosaurs had been in decline for at least 3 million years prior to the Chixalub Impact Event when most of the animals and many plants and fish became extinct. If the Methane Hydride layer at the bottom of the ocean was release as methane (methane is lighter than air) it could have left a layer of good air close to the surface. Bubbling out of the oceans, along with an ocean temperature rise, it would have killed most of the ocean species except for the few that lived in areas of the ocean that did not release the Methane Hydride (where water still had a cooler temperature) or fresh water where no Methane Hydride occurs (as a side note various fish species that go to sea then return to fresh water may have been caused due to escaping the Methane Hydride residual in the sea water). If enough of the Methane Hydride is released all at once it could have filled the atmosphere up to a heavy cloud layer which would have been created by the global warming that was occurring at this time. Some data point to an average rise in temperature of 8 C (14 F) in the last half million years before the impact at Chicxulub. In refering to a program that was presented that 6 C raise in temprature would cause the extinction of the human race what would 8 C (14 F) do compounded by lowered oxygen levels and climatic changes? Most of the animals that lived close to the surface or below would have been mostly left alone while the ocean fish and plants, land plants and animals that were large and/or up in the area where the methane hydride had collected would have died and the few that might have been left alive would have probably died soon after the event, even if the methane hydride would have been washed out of the air because of the climate change that was occurring.
    The fact that, many other large object impacts events have occurred on earth without an extinction event occurring, makes this event suspect. The fact that an Impact event occurred near the same time as an extinction event occurred does not necessarily link it.  The likely hood of an impact event that caused the mass extinction even the size of the Chixalub event seems not very likely or at least not with fire raining down then acid rain, I feel that it is very unlikely to have occurred, especially the issue of Carbon Dioxide as the killer released by the Impact Event. I believe the heating up of the atmosphere due to the Caribbean large igneous province flood Basalt from 139 to 69 million years ago with a volume which has been estimated as on the order of 4 x 106 km, Brito-Arctic province the first which occurred ~61 million years ago was of 2 x 106 km in total volume and Deccan Trapps right at the 65 million year mark with a present volume of directly observable lava flows is estimated to be around 512,000 km. (None of these Flood Basalt Events are Antipode to the Chixalub Event their for probably not related) which occurred at the same time the extinction event occurred which probably heated the atmosphere releasing large quantities of fresh water into the Ocean Conveyor stopping it and allowing the deep sea water to heat enough to release the Methane Hydride layers. It is estimated that the original area covered by the lava flows was as large as 1.5 million km, approximately half the size of modern India. The possibility that an extinction event occurring and only picking and choosing its victims is a little far fetched. The extinction event has to be tailored around the outcome and not the event itself. If everything else has been ruled out no matter how improbable what is left is the answer.

 
 

lyner

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New theory for dinosaur extinction
« Reply #5 on: 22/12/2008 11:14:40 »
It is very risky to expect the behaviour of small water droplets to mimic the behaviour of large scale impacts because forces do not scale.
A bumble bee only flies because  it is the size it is and because of the viscosity of air.  Was it you or the TV programme that made the connection?
« Last Edit: 22/12/2008 19:23:43 by sophiecentaur »
 

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New theory for dinosaur extinction
« Reply #5 on: 22/12/2008 11:14:40 »

 

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