What caused the Older Dryas?
Fauna. Species were mainly Arctic but during the Glacial Maximum, the warmer weather species had withdrawn into refugia and began to repopulate Europe in the Oldest Dryas.
How did the Younger Dryas affect humans?
The warmer and wetter climate in the Southern Hemisphere also helped human migration into South America. At the same time the Younger Dryas in the Northern Hemisphere forced populations either to return to a nomadic lifestyle or seek refuge in a few hospitable areas.
Why is the Younger Dryas called the Younger Dryas?
About 14,500 years ago, Earth’s climate began to shift from a cold glacial world to a warmer interglacial state. This near-glacial period is called the Younger Dryas, named after a flower (Dryas octopetala) that grows in cold conditions and that became common in Europe during this time.
Was the Younger Dryas triggered by a flood?
It is widely believed that this cold event was triggered by a flood of fresh water that poured into the northern Atlantic (1) and disrupted the thermohaline ocean circulation (2).
What caused the 4.2 Kiloyear event?
It has been claimed that the collapse of the state was influenced by a wide-ranging, centuries-long drought. Archaeological evidence documents widespread abandonment of the agricultural plains of northern Mesopotamia and dramatic influxes of refugees into southern Mesopotamia, around 2170 BC.
What caused Dansgaard Oeschger?
The events may be caused by an amplification of solar forcings, or by a cause internal to the earth system – either a “binge-purge” cycle of ice sheets accumulating so much mass they become unstable, as postulated for Heinrich events, or an oscillation in deep ocean currents (Maslin et al.. 2001, p25).
Where is the Younger Dryas comet?
Most recently, the Younger Dryas platinum anomaly has been found in South Africa. This discovery significantly extends the geographic range of the anomaly and adds support to the idea that the Younger Dryas impact was indeed a global event.
When did the Younger Dryas occur?
12,900 and 11,600 years ago
Younger Dryas, also called Younger Dryas stadial, cool period between roughly 12,900 and 11,600 years ago that disrupted the prevailing warming trend occurring in the Northern Hemisphere at the end of the Pleistocene Epoch (which lasted from 2.6 million to 11,700 years ago).
When was the Older Dryas?
The Older Dryas was a stadial (cold) period between the Bølling and Allerød interstadials (warmer phases), about 14,000 years Before Present), towards the end of the Pleistocene. Its date is not well defined, with estimates varying by 400 years, but its duration is agreed to have been around 200 years.
When was the Younger Dryas discovered?
The Younger Dryas (YD) cold event was discovered in Denmark by Hartz and Mithers in 1904 and the term coined by Hartz in 1912.
What caused the Younger Dryas impact?
The Younger Dryas impact is thought to have occurred between 10,800 to 10,900 BC. Again, it might have been caused by the Taurid meteor stream , although this time the general view is that we collided with a swarm of comet debris, rather than a single object.
How long did the Younger Dryas last?
This means that the event took place about 13,000 years ago and lasted for about 1,300 years. The temperatures dropped massively entering into a near-glacial period where it was cold and windy and this is what is known as the Younger Dryas (YD).
Did a bolide cause the Younger Dryas?
This ongoing debate over the ultimate cause of the Younger Dryas has led to a search for other potential forcing mechanisms, such as an abrupt discharge of meltwater to the Arctic Ocean ( Tarasov and Peltier, 2005) and a bolide impact ( Firestone et al., 2007 ).
Is the Younger Dryas a unique deglacial event?
Ultimately, the bolide-forcing hypothesis predicts that the Younger Dryas is a unique deglacial event, as suggested by Broecker (2006).