Basic timeline
In its 4.6 billion years circling the Sun, the Earth has harbored an increasing diversity of life forms:
for the last 3.6 billion years, simple cells (prokaryotes);
for the last 3.4 billion years, cyanobacteria performing photosynthesis;
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Periodic extinctions have temporarily reduced diversity, eliminating: 2.4 billion years ago, many obligate anaerobes, in the oxygen catastrophe;
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for the last 2 billion years, complex cells (eukaryotes);
for the last 1.2 billion years, eukaryotes which sexually reproduce
for the last 1 billion years, multicellular life;
for the last 600 million years, simple animals;
for the last 550 million years, bilaterians, water life forms with a front and a back;
for the last 500 million years, fish and proto-amphibians;
for the last 475 million years, land plants;
for the last 400 million years, insects and seeds;
for the last 360 million years, amphibians;
for the last 300 million years, reptiles;
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Periodic extinctions have temporarily reduced diversity, eliminating: 252 million years ago, the trilobites, in the Permian–Triassic extinction event;
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for the last 200 million years, mammals;
for the last 150 million years, birds;
for the last 130 million years, flowers;
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Periodic extinctions have temporarily reduced diversity, eliminating: 66 million years ago, the pterosaurs and nonavian dinosaurs, in the Cretaceous–Paleogene extinction event.
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for the last 60 million years, the primates,
for the last 20 million years, the family Hominidae (great apes);
for the last 2.5 million years, the genus Homo (including humans and their predecessors);
for the last 200,000 years, anatomically modern humans.
====
Known ice ages
500 million year record shows current and previous two major glacial periods
Name Period (Ma) Period Era
Quaternary 2.58 – present Neogene Cenozoic
Karoo 360 – 260 Carboniferous and Permian Paleozoic
Andean-Saharan 450 – 420 Ordovician and Silurian Paleozoic
Cryogenian
(or Sturtian-Varangian) 800 – 635 Cryogenian Neoproterozoic
Huronian 2400 – 2100 Siderian and Rhyacian Paleoproterozoic
http://en.wikipedia.org/wiki/Timeline_of_glaciation
====
Antarctic Cold Reversal (ACR) episode cooling, during deglaciation at close last ice age. illustrates complexity climate changes at transition Pleistocene to Holocene Epoch.
The Last Glacial Maximum and sea-level minimum occurred c. 21,000 years before the present (BP).
post 18000 BP, show gradual warming. ~14700 BP (12700 BCE) was large pulse meltwater [ID Meltwater Pulse 1A]
probably either Antarctic or Laurentide ice sheet. produced marine transgression raised global sea level 20 m(66ft) in 200-500 yrs,influenced start of Bølling/Allerød interstadial,
major break with glacial cold in Northern Hemisphere. Yet it was followed,in Antarctica & Southern Hemisphere, by renewed cooling,Antarctic Cold Reversal, which set in c.14500 BP (12500 BCE) lasted 2000 yr
[Instance of warming causing cooling. ACR brought average cooling 3°C. Younger Dryas cooling in Northern Hemisphere began while Antarctic Cold Reversal was still ongoing &
ended in midst of Younger Dryas.
This pattern of climate decoupling between Northern-Southern Hemispheres, and "southern lead, northern lag," manifest in subsequent climate events.
Causes of hemispheric decoupling, "lead/lag" pattern, and specific mechanisms of warming and cooling trends, disputed. specific dating-intensity of Antarctic Cold Reversal are under debate.
The onset of the ACR was followed, after about 800 years, by an Oceanic Cold Reversal in the Southern Ocean.
http://www.ldeo.columbia.edu/res/div/ocp/drought/medieval.shtml
The characteristics and likely causes of the Medieval megadroughts in North America
Richard Seager, Celine Herweijer and Ed Cook
Lamont-Doherty Earth Observatory of Columbia University
http://en.wikipedia.org/wiki/Megadrought
External links
Global Drought Information System Current worldwide drought conditions
http://www.drought.gov/gdm/
US Drought Monitor Current U.S. drought conditions
http://droughtmonitor.unl.edu/
Persistent drought in North America: a climate modeling and paleoclimate perspective Lamont-Doherty Earth Observatory of Columbia University
http://www.ldeo.columbia.edu/res/div/ocp/drought/
http://en.wikipedia.org/wiki/Before_Present
http://en.wikipedia.org/wiki/Ice_age
http://en.wikipedia.org/wiki/B%C3%B8lling-Aller%C3%B8d Bølling-Allerød
http://en.wikipedia.org/wiki/Bond_event
Dates are approximate.
Holocene Epoch [Human Era]
Gregorian years ISO 8601 Human Era
early human habitation Gulf Oasis 104450
30001 BC -30000 20000 BHE human habitation strong around Gulf Oasis[Persian] for 100000 years.
Antarctic Cold Reversal (ACR) 19050-20014 BHE Last Glacial Maximum and sea-level minimum occurred c. 21,000 years before the present (BP).
28000 BC ~ End ? Antarctic Cold Reversal (ACR) 18000 BHE show gradual warming
19000 BC Last Glacial Maximum and sea-level minimum occurred c. 21,000 years before the present (BP).
=======
17050--13050 Oldest Dryas occurred during coldest stadial after Weichselian glaciation in north Europe. In Alps, corresponds to Gschnitz stadial of Würm glaciation.
Three “Dryas” periods (younger, older, oldest) named for marker species, Dryas octopetala, detected in core samples of glacial ice and peat bogs.
The Oldest Dryas corresponds to pollen zone Ia.
Dates are approximately
17050 BC Kilkeel, Northern Ireland extends start of period to early as 17050 BC.Start is long, gently sloping band, ~ no earlier than 17050 BC, date might be ~1000 years later.
14700 South China sea ice core?
14600 Antarctica ice core
14500 Greenland ice core
12700 BC calibrated. end of the Oldest Dryas [C-14 dates from layered material in Hauterive/Rouges-Terres excavations on northwest shore Lake Neuchâtel Switzerland,1992–93
16,050-13,050 BC , from Roberts, 1998.
The selection of a terminal point is sometimes partially arbitrary.
End of Oldest Dryas sharply defined.
Data derived isotope variation nitrogen - argon trapped Greenland ice gives hi-res date for end of oldest Dryas at sharp temperature rise of 14.67 ky BP.
http://en.wikipedia.org/wiki/Oldest_Dryas
=======
========
16000-13000 BC Older Dryas occurred ~ 1000 years before Younger Dryas,lasted ~300 yrs. dated ~18000-15000 BP [14000 years ago BP]
stadial (cold) period between Bølling-Allerød oscillations (warmer phases) near end Pleistocene epoch.
Gradual warming since peak of last glacial period 22000 yrs BP interrupted by three cold spells, Older Dryas preceded by Oldest Dryas,followed by Younger Dryas.
Named after indicator genus, arctic and alpine plant Dryas, fossils found in higher concentrations in deposits from colder periods.
The Older Dryas was a variable cold, dry Blytt-Sernander period, observed in climatological evidence in only some regions, depending on latitude.
In regions not observed, Bølling-Allerød is considered a single interstadial (warm) period. Evidence of Older Dryas is strongest in northern Eurasia, North Europe roughly equivalent Pollen zone Ic.
http://en.wikipedia.org/wiki/Older_Dryas
=========
============= [Meltwater Pulse 1A]& Bølling/Allerød interstadial = warm period = Humans north Eurasia still hunter-gather stage
14700 BHE [Meltwater Pulse 1A] large pulse,fr Antarctic or Laurentide ice sheet.marine transgression raised global sea level 20 m (66ft) in 200-500 yrs, influenced start of Bølling/Allerød interstadial
14500-14200 ~ calc. End sea level rise from [Meltwater Pulse 1A]
14700-12700 BHE Bølling/Allerød interstadial = warm period in final stages last glacial period.[major break glacial cold in North Hemi]
13000-14000 [14100 BP Greenland oxygen isotope record]
Humans north Eurasia still hunter-gather stage. variety Palaeolithic cultures prevailed in Europe:
Federmesser,Lyngby, Bromme, Ahrensburg and Swiderian. To south & far east the Neolithic had already begun.
http://en.wikipedia.org/wiki/B%C3%B8lling-Aller%C3%B8d http://en.wikipedia.org/wiki/B%C3%B8lling_oscillation http://en.wikipedia.org/wiki/Aller%C3%B8d_oscillation
= = = =
12000-10200 BC Natufian period was between , "proto-neolithic" [now inc in Pre-Pottery Neolithic (PPNA)] become dependent wild cereals in diet, sedentary way of life emerged,
10200-8800 Pre-Pottery Neolithic (PPNA) farming communities arose Levant ,spread Asia Minor, N Africa and N Mesopotamia. Early Neolithic farming limited narrow range plants,both wild and domesticated,
[einkorn wheat, millet , spelt, and keeping of dogs, sheep , goats
=========== Younger Dryas stadial, aka Big Freeze http://en.wikipedia.org/wiki/Younger_Dryas
10,800-9500 BC Younger Dryas stadial,aka Big Freeze,geologically brief (1,300 ± 70 years) period cold climatic conditions-drought occurred between 12,800-11,500 years BP .
Maybe caused by collapse of N American ice sheets, although rival theories have been proposed.
It followed Bølling-Allerød interstadial (warm period) at end of Pleistocene and preboreal of early Holocen
Ireland[Nahanagan Stadial] [United Kingdom Loch Lomond Stadial] [Greenland Stadial 1 (GS1).
Younger Dryas (GS1) is also a Blytt-Sernander climate period detected from layers in north European bog peat.
The Dryas stadials were cold periods which interrupted warming trend since Last Glacial Maximum 20000 years ago.
10200 BC Start Neolithic Era-Period,New Stone Age,period dev human tech some parts Middle East.progression behavioral-cultural characteristics-changes,inc. use wild-domestic crops & domesticated animals
10001 BC -10000 [ 0 HE]
10000 BC -9999 [ 1 HE]
9001 BC -9000 [1000 HE]
===========
Birth of Agriculture?
9500-8800 prob bds c Big Freeze [Range 10200–8800 BC] Levant Jericho,modern-day West Bank from Epipaleolithic Natufian culture in region, who pioneered use wild cereals, which evolved true farming.
Climatic changes associated with Younger Dryas thought forced people to develop farming.
8000 BC [2001 HE] Birth of Agriculture ??
=====
7500–7000 BCE - 3500–3000 BCE Neolithic Subpluvial http://en.wikipedia.org/wiki/Neolithic_Subpluvial
The Neolithic Subpluvial aka Holocene Wet Phase — was extended period of wet and rainy conditions in climate history northern Africa.
It was both preceded and followed by much drier periods.
Neolithic Subpluvial periods of "Wet Sahara" or "Green Sahara", during region much more moist,supported a richer biota,human population than present-day desert.
began during 7th millennium BC and strong for 2000 years; waned over time and ended after 5.9 kiloyear event (3900 BCE).
Then drier conditions prevailing prior to Neolithic Subpluvial returned; desertification advanced, and Sahara desert formed (or re-formed).
Arid conditions continued through to present day.
=====
6900–6400 BC, domesticated cattle and pigs, establishment permanently or seasonally inhabited settlements, use of pottery.
====COLD------------------------
6200 BC 8.2 kiloyear event ~start COLD [3700-3750 HE] Sudden colder temp last 200-400 yr. Milder than Younger Dryas spell preceded, more severe Little Ice Age following,sig.
Exception Holocene climatic general trends of optimum. http://en.wikipedia.org/wiki/8.2_kiloyear_event
Atmospheric methane concentration decreased by 15% [80 ppb] emission reduction by cooling-drying at hemispheric scale
6000-5800 BC 8.2 kiloyear event ~end [3900-4150 ] End cool period
====-End cool--------------------
5551 BC [4450 HE] Sudden increase settlements above Gulf Oasis[Persian] present water level recorded at ~ 7,500 BP
====4500 BC [Range Start 4500 -2000BC} Start Neolithic Era-Period,New Stone Age,period dev human technology some parts of Middle East
-=-=--=
4300–3300 BCE of the Chalcolithic period (Copper Age)
7700?–3300 BCE inhabitants of Mehrgarh in Pakistan fashioned tools with local copper ore (ore used as pigment)
The emergence metallurgy maybe first in Fertile Crescent, suggest considerable mobility and trade. Indus Civilization, southern Turkmenistan, and northern Iran
it gave rise to Bronze Age in the 4th millennium BCE
http://en.wikipedia.org/wiki/Chalcolithic
Serbia, copper axe found Prokuplje, indicates humans using metals in Europe by 7500 years ago (~5,500 BCE), years earlier than believed.
Knowledge of use of copper was more widespread than metal itself.
European Battle Axe culture used stone axes modeled on copper axes, even imitation "mold marks" carved in stone.
Ötzi the Iceman, found in Ötztal Alps 1991 remains dated ~3300 BCE, was found with Mondsee copper axe.
-=-=--=
=-=-=-=- ARID
3900 BC 5.9 kiloyr aridification event [7001 HE] Intense Holocene Epoch.end Neolithic Subpluvial,start desiccation Sahara desert & ww migration to
river valleys[central N. Africa to Nile valley] led emergence complex,organized, state-level societies 4th millennium BC.,
Associated last round Sahara pump theory.
hypothesis how flora-fauna migrated Eurasia-Africa via Levantine land bridge.
extended periods abundant rainfall lasting many thousands of years (pluvial periods) in Africa "wet-Sahara" phase,during larger lakes-more rivers existed.
Migration along river corridor halted when,during desert phase 1.8–0.8 million years ago (mya), Nile ceased flow completely
and flowed only temporarily in periods due to geologic uplift (Nubian Swell) of Nile River region.
http://en.wikipedia.org/wiki/Sahara_pump_theory
=-=-=-=- ARID
=-=-=-=-FLOOD cold-wet
3200-2900 BCE Piora Oscillation abrupt cold-wet period in climate history of Holocene Epoch,maybe end of Atlantic climate regime,start of Sub-Boreal, in Blytt-Sernander sequence of Holocene climates.
http://en.wikipedia.org/wiki/Piora_Oscillation
phenomenon named after Piora Valley Switzerland, where first detected;most dramatic evidence of Piora Oscillation comes from Alps region. Glaciers advanced in Alps, apparently for first time since Holocene climatic optimum;
Alpine tree line dropped by 100m. Yet climate change extended far beyond Alps-Europe. It affected New England region North America, hemlock-elm trees suffered dramatic decline.
In Middle East, the surface of Dead Sea rose nearly 100 meters (300 feet), then receded to more usual level.
linked domestication horse. Central Asia, colder climate favored use: "The horse, since so adept at foraging with snow on the ground, tended to replace cattle and sheep."
Piora period seems associated with period colder drier air over Western-Eastern Mediterranean, may have depressed rainfalls as far as Middle East.
Also associated with sudden onset drier weather in the central Sahara.
causes of Piora Oscillation debated. Greenland ice core,GISP2, shows sulfate spike-methane trough c. 3250 BCE, suggesting volcanic eruption,meteor,asteroid impact event.
Some associate Piora Oscillation with other comparable events, like 8.2 kiloyear event, that recur climate history, part of larger 1500-year climate cycle.
3000-2900 BC FLOOD documented Mesopotamia 6450-6350 HE filling Persian Gulf after sea waters rose following the last ice age???? [or Piora Oscillation bds??].
3300–2100 BC Early Bronze Age (EBA)http://en.wikipedia.org/wiki/Bronze_Age
~3300 BCE Ötzi the Iceman,found in Ötztal Alps 1991 remains dated,found with Mondsee copper axe.
==---==---==
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
predicts bds using 1500-3000 Ocillation cycle rule
FLOOD cold-wet period
[0 - 200 ad - ??? when was Noah predict bds]
1700-1900 [1350-1850, 1550-1850 NASA Little Ice Age]
3200-3400 [Future]
arid period
700 - 600 bc [early 1st millennium BC [700 - 600 bc] drought in the Eastern Mediterranean, possibly triggering the collapse of Late Bronze Age cultures] ,
900-1000 ad [950-1250 AD Medieval Warm Period ? was dry 100 yr of 300 yr period? yes1Bingo N America four+ megadroughts in Medieval Warm Period 935-1034-1150-1253 ] ,
2400-2500 [Future]
should have been a ??? predict bds arid
validation ? :
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
=-=-=-=-=-=-=-=- ARID
2200-2101 BC 4.2 kiloyr aridification event 8701-7900 HE [22d cen BC 2200-2101 BC] severe climatic event Holocene period terms cultural upheaval impact.
caused collapse Old Kingdom Egypt & Akkadian Empire in Mesopotamia. http://en.wikipedia.org/wiki/4.2_kiloyear_event
drought may initiated southeastward habitat tracking within Indus Valley Civilization.
=-=-=-=-=-=-=-=- ARID
2100–1550 BC Middle Bronze Age (MBA) Aka, Intermediate Bronze Age (IBA) http://en.wikipedia.org/wiki/Bronze_Age
1100-
Note: In Paleolithic > one human species existed, only Homo sapiens sapiens reached Neolithic. Homo floresiensis may have survived up to dawn of Neolithic, 12200 years ago.
====2000 BC [Range End 4500 -2000BC} End Neolithic Era or Period,New Stone Age,period development human technology in some parts of Middle East
1550–1200 BC Late Bronze Age (LBA) http://en.wikipedia.org/wiki/Bronze_Age
1100 BC - 600 ad Early Iron Age http://en.wikipedia.org/wiki/Iron_Age
1000 BC -0999 9001 HE
510 bc - 290 ad Middle Iron Age
100 BC -0099 9901 HE
4 BC -0003 9997 HE Birth Jesus
2 BC -0001 9999 HE
1 BC +0000 10000 HE
1 AD +0001 10001 HE
2 AD +0002 10002 HE
290 - 340 Late Iron Age
http://en.wikipedia.org/wiki/Bond_event
Bølling oscillation
http://en.wikipedia.org/wiki/B%C3%B8lling_oscillation
=====
376 to 800 AD Migration Period aka period barbarian invasions or Völkerwanderung (migration of peoples), period intensive Europe human migration during transition from Late Antiquity to Early Middle Ages.
marked by profound changes both within the Roman Empire and beyond its "barbarian frontier".
migrants who came first were Germanic tribes such as the Goths, Vandals, Angles, Saxons, Lombards, Suebi, Frisii, Jutes and Franks;
they were later pushed westwards by the Huns, Avars, Slavs, Bulgars and Alans.
Note: Later migrations (such as the Arab conquest and Viking, Norman, Hungarian, Moorish, Turkic, and Mongol invasions) also had significant effects
(especially in North Africa, the Iberian peninsula, Anatolia and Central and Eastern Europe);
however, they are outside the scope of the Migration Period.
http://en.wikipedia.org/wiki/Migration_Period
=====
=====
950-1250 AD Medieval Warm Period
950-1100 Warmest period of last 2000 yrs prior to 20th century
http://en.wikipedia.org/wiki/Medieval_Warm_Period
Medieval Warm Period (MWP), Medieval Climate Optimum, or Medieval Climatic Anomaly was a time of warm climate in the North Atlantic region that may also have been related to other climate events around the world during that time, including China[1] and other areas, [2][3] lasting from about AD 950 to 1250.[4] It was followed by a cooler period in the North Atlantic termed the Little Ice Age. Some refer to the event as the Medieval Climatic Anomaly as this term emphasizes that effects other than temperature were important.[5][6]
Despite substantial uncertainties, especially for period prior 1600 data scarce,
Temps probably 0.1-0.2 °C below 1961 to 1990 mean & much below level shown by instrumental data after 1980.
Proxy records from different regions show peak warmth at different times during Medieval Warm Period, indicating heterogeneous nature climate at time.
Temps in some regions matched-exceeded recent temps in these regions, but globally Medieval Warm Period was cooler than recent global temperatures.
====
===
1350-1850 Little Ice Age http://en.wikipedia.org/wiki/Little_Ice_Age
1550-1850 NASA and notes 3 real cold intervals: 1 beginning ~1650, another ~1770, and last ~1850, each separated by intervals of slight warming.
c timing and areas affected suggested largely independent regional climate changes, rather than lobally synchronous increased glaciation.
At most modest cooling of Northern Hemisphere during the period.
Several causes have been proposed: cyclical lows in solar radiation, heightened volcanic activity, changes in ocean circulation, inherent variability global climate, or decreases in human population.
===
1950 AD 11950 HE Standard Pre Atomic Testing Carbon dating
2014 AD +2014 12014 HE
10000 AD +10000 20000 HE
Conversion to the Human Era from Julian or Gregorian AD years can be achieved by adding 10,000.
BC years are converted by subtracting the BC year from 10,001.
A useful validity check is that the last single digits of BC and HE equivalent pairs must add up to 1 or 11.
Mesopotamia, human habitation strong around Gulf Oasis[Persian] for 100000 years. Sudden increase settlements above present water level recorded at ~ 7,500 BP
The birth year of Jesus Christ. The era places Jesus' birth year in 1 BC, but modern scholars have determined that he was born in or before 4 BC
Holocene calendar, aka Holocene Era (HE) Human era, year numbering system adds exactly 10,000 years to currently world-dominant Anno Domini (AD) or Common Era (CE) system,
placing its first year near the beginning of the Holocene epoch and the Neolithic revolution.
Human Era proponents claim that it makes for easier geological, archaeological, dendrochronological and historical dating, as well as that it bases its epoch on an event more universally relevant than the birth of Jesus. The current year of AD 2014 can be transformed into a Holocene year by adding the digit "1" before it, making it 12014 HE. The Human Era was first proposed by the scientist Cesare Emiliani in 1993.[1][2][3]
http://en.wikipedia.org/wiki/Timeline_of_natural_history
http://en.wikipedia.org/wiki/Geological_history_of_Earth
http://en.wikipedia.org/wiki/Detailed_logarithmic_timeline
http://en.wikipedia.org/wiki/North_America
|
??
Uruk period, as a Dark Age associated with the floods of the Gilgamesh epic and Noah's flood of the Book of Genesis.