evolution of biosphere and cryosphere
TRANSCRIPT
Contents Introduction
Hypothesis
Archean Biosphere
Biosphere Evolution
Important stages of Biosphere
Ecosystem and Biomes(Major Biomes)
Distribution Of Major Terrestrial Biomes
Cryosphere
Role of Cryosphere in Climate System
Snow Distribution and Variation
Structure Of Cryosphere
Conclusion
References
INTRODUTION The process of the origin and evolution of living organisms is
indivisible from the process of the origin and evolution of
Biosphere. The most general features of biosphere evolution as a
directed process are formulated in the Principle of “bio-
actualism”. It is demonstrated, that this principle, stated for
Phanerozoic eon, hold for early biosphere up to the period of
biosphere coming into being.
"Bio" means life, and the term biosphere, had first coined by
Eduard Seuss ,the term biosphere more than hundred years ago,
it is Vladimir Vernadsky’s concept of the biosphere, formulated in
1926,Another term sometimes used is ecosphere ("eco" meaning
home).
Cont…
Biosphere is a specific envelope of the Earth, comprising totality of
all living organisms and that part of planet matter which is in
constant material exchange with these organisms. It is a feature that
distinguishes the earth from the other planets in the solar system.
The biosphere includes the outer region of the earth (the lithosphere)
and the lower region of the atmosphere (the troposphere). It also
includes the hydrosphere, the region of lakes, oceans, streams, ice
and clouds comprising the earth's water resources.
Traditionally, the biosphere is considered to extend from the bottom
of the oceans to the highest mountaintops, a layer with an average
thickness of about 20 kilometers. Scientists now know that some
forms of microbes live at great depths, sometimes several thousand
meters into the earth's crust
HYPOTHESIS Traditionally, the problem of the origin of life on Earth is the
study of how biological life across from inorganic matter and
primary living organisms spread around the planet.
Some philosophers and scientists such as Helmholtz and
Arrhenius proposed the hypothesis of “panspermia” ,The place
and the origin of life is from outside the Earth somewhere in
cosmos.
The abiogenesis hypothesis claims that life emerged from non-
living matter in early terrestrial conditions. This is the traditional
approach to the question of life’s origin.
Main questions of abiogenesis hypothesis are reduced to an
origin of biological membranes via emergence of ionic
asymmetry of the cells and chiral asymmetry of bio molecules.
BIOSPHERE Virtually all life on earth exists in biosphere, that area between several
kilometer above the surface of the earth to several kilometers below the
surface .
The biosphere is a very tiny region on the scale of the whole earth, analogous to the
thickness of the skin on an apple. The bulk of living organisms actually live within a
smaller fraction of the biosphere, from about 500 meters below the ocean's surface to
about 6 kilometres above sea level.
PUTTING IT INTO PERSPECTIVE If the universe were scaled down to the size of the surface of
the earth, our solar system would equal the size of a single
bacterial cell.
Our biosphere wouldn’t even register as a single atom on the
planet’s surface .
Archaean biosphere
The Archaean biosphere was probably an oxygenic and
chemotropic, With oxidized ‘‘spots’’ of oxygenic photo synthetics .
The inversion of that Biosphere with irreversible oxygenation of
the atmosphere by cyanobacteria began 2 Byr ago, after large
amounts of Fe3O4 ore mass were buried . Then the iron cycle in
the biosphere was replaced by the sulfur cycle.
These cycles are incompatible sulfate reduction brings all free iron
into sulfides. Before that, sulfur was likely to concentrate in the
crust.
For example, in Precambrian volcanite in the form of sulfides. So
the immensely large iron ‘‘reservoir,’’ which used to bind free
Pre -Cambrian period was a time of immense change in the nature of the biosphere, characterized by glaciations of possible global extent (the so-called ‘Snowball Earth)
Biosphere Evolution
Biosphere evolution: upper row—biosphere evolution milestones; middlerow—the age-related distribution of cyanobacteria (Zavarzin, 2001)
Important Stages of Biosphere Evolution
Basic stages of climate evolution, earth’s crustevolution and biosphere evolution
Ecosystem Dynamic interactions between plants ,animals ,micro organisms
and their environment ,working together as a functional unit.
Ecosystem will fail if they do not remain in balance .
No community can carry more organisms than it food ,water andshelter can accommodate .
Food and territory are often balanced by natural phenomena (fire,disease and predatarors).
Each organism has its own role to play .
Biome A biome is a large area with similar flora, fauna, and micro
organisms.
Examples :
Tropical rain forest
Tundra in the arctic regions
Evergreen trees in the coniferous forests
Confusion about Ecosystem and
Biome ? Ecosystem
- can be as large as the sahara desert, or as small as a
puddle or vernal pool.
Biome
-many similar ecosystems thoughts the world grouped
together
Major Biomes Mountains (high elevation)
Tundra
Temperate forest
Marine/island
Desert
Tropical dry forest
Cold climate forest
scrub
Grassland
Savannah
Tropical rainforest
The Distribution Of Major Terrestrial Biomes
Cryosphere
Cryo(frozen) , a component of the
earth’s Climate system comprised of
water in its solid state
It consist of
Glaciers and ice sheets
Snow
Permafrost
Sea ice (perannia and seasonal)
The cryosphere is an integral part of the global climatesystem with important linkages and feedbacks generatedthrough its influence on surface energy and moisture ,fluxes, clouds , precipitation , hydrology
Thus the cryosphere plays a significant role in the globalclimate model response to global changes .
Climates of the Earth and Cryosphere Evolution We very often consider that we live in a warm climate. Through this travel in the
deep ages of the Earth, we shall see that this idea is mostly wrong.
During the Earth’s history. A striking feature is that, most of the time, there is just
no cryosphere at all.
The most common climate state of our planet is in fact warm . Since the
Precambrian explosion, 540 Ma ago the period that is best documented.
The glacial periods are also very infrequent. For instance, the dinosaurs, which
lasted very long (220–65 Ma), lived during warm climates without any ice sheet
most of the time .
In contrast, the period where we presently live (the Quaternary) with two ice
sheets (one in each hemisphere) in the last2.6 Ma is indeed a cold period and one
of the rare periods on the geological timescale.
For more than 1 Ma, the climate has shifted from glacial (80%) to interglacial
(20%). During the glacial period, four ice sheets existed, Greenland and Antarctica,
two extra ice sheets were located over the northern parts of North America and
over the north of Europe .
In the most recent 14,000 years, we are in a warm interglacial climate during
which human population has spread all over the world.
Role of cryosphere climate system Largest of fresh water storage
> influence sea level rise
>water resource
>influence ocean circulation
Regular earth’s albedo(reflection of light)change.
Reduce turbulent transport of heat ,water and momentum
Change in ocean buoyancy flux.
Glacier runoff from Antarctica in a major source of fresh water
for southern ocean .
Regular regional global climate .
Milankovitch theory describes the collective effects of changes in the Earth’s movements upon its climate,
87% of ice is in Antarctica10% Greenland2.5% ice shelves (mostly Antarctic)
If all Ice melted sea levels would go up by about 65 meters (213 ft)
snow distribution and variation
The map shows how snow is distributed across the globe (in winter time).Well, of course, this excludes the two poles which have much more snow andthroughout the year. I also see how South America and South East Asia are evergreen throughout the year. By NOAA
Satellite sensors: METOP-A AVHRR, DMSP F-16,-17 and -18 SSMIS, GOES-East and -West Imager, MSG SEVIRI
Glacier A glacier is a persistent body of dense ice exceeding a surface area of
0.1 km² constantly moving under its own gravity which forms where the accumulation of snow exceeds its ablation (melting )
On Earth 99% of glacial ice is contained within vast ice sheets in the polar regions but glaciers may be found in mountain ranges on every continent and on a few high-latitude oceanic island.
Glacial ice is the largest reservoir of freshwater on Earth, supporting one third of the world's population.
Antarctica ice sheet• Is one of the two polar ice caps of the Earth. It covers about 98% of
the Antarctic continent and is the largest single mass of ice on Earth.
• It covers an area of almost 14 million square km and contains 26.5 million cubic km of ice. That is, approximately 61 percent of all fresh water on the Earth is held in the Antarctic ice sheet.
The icing of Antarctica began with ice-rafting from middle Eocene times about 45.5 million years ago[ and escalated inland widely during the Eocene–Oligocene extinction event about 34 million years ago.
Alpaine Glacier
Antarctic ice sheet
Greenland ice sheet
It cover around 1,710,000 sq kilometres
( 80% of the surface of Greenland )
It is the second largest ice body in the world,
after the Antarctic Ice Sheet.
It is not the only ice mass of Greenland –
isolated glaciers and small ice caps cover
between 76,000 and 100,000 sq kilometres
The ice in the current ice sheet is as old as
110,000 years. .
The Greenland Ice Sheet formed in the
middle Miocene by coalescence of ice caps and glaciers.
There was an intensification of glaciation during the Late
Pliocene
Sea ice
Sea ice covers much of the polar oceans and forms by freezing of
sea water. Satellite data since the early 1970s reveal considerable
seasonal, regional, and interannual variability in the sea ice covers
of both hemispheres.
Seasonally, sea-ice extent in the Southern Hemisphere , from a
minimum of 3-4 million km² in February to a maximum of 17-20
million km² in September.
The seasonal variation is much less in the Northern Hemisphere
where the confined nature and high latitudes of the Arctic Ocean
result in a much larger perennial ice cover .The seasonal variability
in Northern Hemisphere ice extent from a minimum of 7-9 million
km² in September to a maximum of 14-16 million km² in March
Conclusion Biosphere is a specific envelope of the Earth, The biosphere
includes the outer region of the earth (the lithosphere) and the
lower region of the atmosphere (the troposphere).
The origin of Biosphere is from the biological membranes via
emergence of ionic asymmetry of the cells and chiral
asymmetry of bio molecules .
Important stages of Biosphere evolution was from RNA
synthesis on montmorillonite to many celled organisms
Biosphere includes the Biome ,Ecosystem ,Community
,Population ,Individual
Cont….. Cryosphere composed of earth’s climate system ,comprised of
water in its solid state.
we presently live with two ice sheets (one in each hemisphere)
in the last2.6 Ma is indeed a cold period and one of the rare
periods on the geological timescale.
Largest mass in Antarctica and Greenland cover 58m deep of
water globally if they melt completely.
Sea ice land snow cover around 8-16% of earth’s surface .
Green land and W Antarctica ice sheet ,arctic sea ice and alpine
glacier have retreated rapidly in recent decades.
The cryosphere plays a significant role in the global climate
model response to global changes .
Refrences Nikolay Dodretsov, Nikolay Kochanaov, Alexey Rozanov , Georgy Zavarzin
,Biosphere Origin and Evolution ,Springer Publishser ,pp 7-15,22-28
Chyba, C.F. and McDonald, G.D. (1995) The origin of life in the solar
system: current issues.
Annu. Rev. Earth Planet. Sci. 23, 215–249.
Malgorzata Moczydlowska-Vidal ,The evolution of the Earth and its
biosphere , Uppsala University, Department of Earth Sciences, Palaeobiology
,pp 22-32.
Vladimir F. Levchenko, Alexander B. Kazansky, Marat A. Sabirov and
Eugenia M. Semenova , Early Biosphere: Origin and Evolution , Laboratory
of Evolution Modeling, Institute of Evolutionary Physiology and
Biochemistry of the Russian, Academy of Sciences, St. Petersburg Russian
Federation , pp 5-12 ,15-22 ,27 -28
• Gilles Ramstein , Surv Geophys (2011) , Climates of the Earth and
Cryosphere Evolution , Received: 18 March 2011 / Accepted: 9 June 2011
Springer publisher ,pp 331-334 ,339-342.
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