Piora Oscillation

The Piora Oscillation was an abrupt cold and wet period in the climate history of the Holocene Epoch; it is roughly dated to c. 3900-3000 BC. Some researchers associate the Piora Oscillation with the end of the Atlantic climate regime, and the start of the Sub-Boreal, in the Blytt–Sernander sequence of Holocene climates.

The spatial extent of the change is unclear; it does not show up as a major, or even identifiable, event in hemispheric temperature reconstructions.

Contents

First detection

The phenomenon is named after the Val Piora or Piora Valley in Switzerland, where it was first detected; some of the most dramatic evidence of the Piora Oscillation comes from the region of the Alps. Glaciers advanced in the Alps, apparently for the first time since the Holocene climatic optimum; the Alpine tree line dropped by 100 meters. In the Middle East, the surface of the Dead Sea rose nearly 100 meters (300:feet), then receded to a more usual level. A few commentators have associated the climate changes of this period with the end of the Uruk period, as a Dark Age associated with the floods of the Gilgamesh epic and Noah's flood of the Book of Genesis.

Link to horse domestication

The Piora Oscillation has also been linked to the domestication of the horse. In Central Asia, a colder climate favored the use of horses: "The horse, since it was so adept at foraging with snow on the ground, tended to replace cattle and sheep." The Piora period seems associated with a period of colder drier air over the Western and Eastern Mediterranean, and may have depressed rainfalls as far afield as the Middle East. It is also associated with a sudden onset of drier weather in the central Sahara.

Causes

The cause or causes of the Piora Oscillation are debated. A Greenland ice core, GISP2, shows a sulfate spike and methane trough c. 3250 BCE, suggesting an unusual occurrence — either a volcanic eruption or a meteor or an asteroid impact event. Other authorities associate the Piora Oscillation with other comparable events, like the 8.2 kiloyear event, that recur in climate history, as part of a larger ...read more

Last Glacial Maximum
5 months ago

Last Glacial Maximum ... kiloyear event 5.9 kiloyear event 4.2 kiloyear event Older Peron Piora Oscillation Little Ice Age – A period of cooling after the Medieval Warm Period...

Climate variability and change
5 months ago

Climate variability and change ... Since that time, several cooling events have occurred, including: the Piora Oscillation the Middle Bronze Age Cold Epoch the Iron Age Cold Epoch the Little...

8.2-kiloyear event
4 months ago

8.2-kiloyear event ... period Bond event Antarctic Cold Reversal Little Ice Age Older Peron Piora Oscillation Sahara pump theory Younger Dryas Current sea level rise 5.9-kiloyear...

African humid period
4 months ago

African humid period ... The African humid period ended 6,000–5,000 years ago during the Piora Oscillation cold period. While some evidence points to an end 5,500 years ago...

Ice age
2 months ago

Ice age ... the last 800,000 years, the dominant period of glacial–interglacial oscillation has been 100,000 years, which corresponds to changes in Earth's orbital...

Holocene
6 months ago

Holocene ... Holocene extinction Neolithic Subpluvial Older Peron Outburst flood Piora Oscillation Quaternary extinction event Walker, Mike; Johnse, Sigfus; Rasmussen...

Younger Dryas
6 months ago

Younger Dryas ... both the Bølling oscillation and the Allerød oscillation interstadials. The cold period that occurred within the Bølling oscillation is known as the intra-Bølling...

Sumer
6 months ago

Sumer ... Alulim and Dumizid. The end of the Uruk period coincided with the Piora oscillation, a dry period from c. 3200–2900 BC that marked the end of a long wetter...

List of periods and events in climate history
4 months ago

List of periods and events in climate history ... Sahara Desert 3,000 BC - 0 Neopluvial in North America 3,200–2,900 BC Piora Oscillation, cold, perhaps not global. Wetter in Europe, drier elsewhere, linked...

Last Glacial Period
4 months ago

Last Glacial Period ... of the Devensian includes Pollen zones I–IV, the Allerød oscillation and Bølling oscillation, and Oldest Dryas, the Older Dryas and Younger Dryas cold...

Interglacial
5 months ago
Little Ice Age
6 months ago
Esker
5 months ago
Kettle (landform)
6 months ago
Canadian Shield
5 months ago
Timeline of prehistory
4 months ago
Lake Agassiz
6 months ago
Pleistocene
5 months ago
Champlain Sea
4 months ago
This article is copied from an article on Wikipedia® - the free encyclopedia created and edited by its online user community. This article is distributed under the terms of GNU Free Documentation License.