Mousterian Pluvial
Encyclopedia
The Mousterian Pluvial was an extended wet and rainy period in the climate
history of North Africa
. It occurred during the Upper Paleolithic
era, beginning around 50,000 years before the present (ybp
), lasting 20,000 years, and ending around 30,000 ybp (years before present).
During the Mousterian
Pluvial
, the now-desiccated regions of northern Africa were well-watered, bearing lakes, swamps, and river systems that no longer exist. What is now the Sahara desert supported typical African wildlife of grassland and woodland environments: herbivores from gazelle
to giraffe
to ostrich
, predators from lion
to jackal
, even hippopotamus
and crocodile
, as well as extinct forms like the Pleistocene camel
. In these respects the Mousterian Pluvial resembled the earlier Abbassia Pluvial
; the later Neolithic Subpluvial
was a weaker re-iteration of the same pattern.
The Mousterian Pluvial was caused by large-scale climatic
changes during the last ice age
. By 50 kybp (thousand years before present), the Wisconsin glaciation
("Würm glaciation" in Europe) was well-advanced; growing ice sheet
s in North America and Europe displaced the standard climatic zones of the northern hemisphere southward. The temperate zones of Europe and North America acquired an Arctic or tundra
climate, and the rain bands typical of the temperate zones dropped to the latitudes of northern Africa.
Curiously, the same influences that created the Mousterian Pluvial also appear to have brought it to a close. In the period of its fullest development, c. 30 to 18 kybp, the Laurentide ice sheet
not only covered an enormous geographic area, but increased its altitude to 1750 meters (more than 1 mile). It generated its own long term weather patterns, which affected the jet stream
passing over the North American continent. The jet stream effectively split in two, creating a new dominant weather pattern over the northern hemisphere that brought harsher conditions to several regions (including parts of Central Asia
and the Middle East
) — changes that included an end to the Mousterian Pluvial and a return to a more arid climate in northern Africa.
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
history of North Africa
North Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...
. It occurred during the Upper Paleolithic
Upper Paleolithic
The Upper Paleolithic is the third and last subdivision of the Paleolithic or Old Stone Age as it is understood in Europe, Africa and Asia. Very broadly it dates to between 40,000 and 10,000 years ago, roughly coinciding with the appearance of behavioral modernity and before the advent of...
era, beginning around 50,000 years before the present (ybp
Before Present
Before Present years is a time scale used in archaeology, geology, and other scientific disciplines to specify when events in the past occurred. Because the "present" time changes, standard practice is to use AD 1950 as the origin of the age scale, reflecting the fact that radiocarbon...
), lasting 20,000 years, and ending around 30,000 ybp (years before present).
During the Mousterian
Mousterian
Mousterian is a name given by archaeologists to a style of predominantly flint tools associated primarily with Homo neanderthalensis and dating to the Middle Paleolithic, the middle part of the Old Stone Age.-Naming:...
Pluvial
Pluvial
In geology and climatology, a pluvial was an extended period of abundant rainfall lasting many thousands of years. Pluvial is also applied to the sediments of these periods . The term is especially applied to such periods during the Pleistocene Epoch...
, the now-desiccated regions of northern Africa were well-watered, bearing lakes, swamps, and river systems that no longer exist. What is now the Sahara desert supported typical African wildlife of grassland and woodland environments: herbivores from gazelle
Gazelle
A gazelle is any of many antelope species in the genus Gazella, or formerly considered to belong to it. Six species are included in two genera, Eudorcas and Nanger, which were formerly considered subgenera...
to giraffe
Giraffe
The giraffe is an African even-toed ungulate mammal, the tallest of all extant land-living animal species, and the largest ruminant...
to ostrich
Ostrich
The Ostrich is one or two species of large flightless birds native to Africa, the only living member of the genus Struthio. Some analyses indicate that the Somali Ostrich may be better considered a full species apart from the Common Ostrich, but most taxonomists consider it to be a...
, predators from lion
Lion
The lion is one of the four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg in weight, it is the second-largest living cat after the tiger...
to jackal
Jackal
Although the word jackal has been historically used to refer to many small- to medium-sized species of the wolf genus of mammals, Canis, today it most properly and commonly refers to three species: the black-backed jackal and the side-striped jackal of sub-Saharan Africa, and the golden jackal of...
, even hippopotamus
Hippopotamus
The hippopotamus , or hippo, from the ancient Greek for "river horse" , is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest...
and crocodile
Crocodile
A crocodile is any species belonging to the family Crocodylidae . The term can also be used more loosely to include all extant members of the order Crocodilia: i.e...
, as well as extinct forms like the Pleistocene camel
Camelops
Camelops is an extinct genus of camels that once roamed western North America, where it disappeared at the end of the Pleistocene about 10,000 years ago. Its name is derived from the Greek κάμελος + , thus "camel-face."-Background:...
. In these respects the Mousterian Pluvial resembled the earlier Abbassia Pluvial
Abbassia Pluvial
The Abbassia Pluvial was an extended wet and rainy period in the climate history of North Africa. It began c. 120,000 years before the present , lasted approximately 30,000 years, and ended c. 90,000 ybp...
; the later Neolithic Subpluvial
Neolithic Subpluvial
The Neolithic Subpluvial — sometimes called the Holocene Wet Phase — was an extended period of wet and rainy conditions in the climate history of northern Africa...
was a weaker re-iteration of the same pattern.
The Mousterian Pluvial was caused by large-scale climatic
Climatology
Climatology is the study of climate, scientifically defined as weather conditions averaged over a period of time, and is a branch of the atmospheric sciences...
changes during the last ice age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
. By 50 kybp (thousand years before present), the Wisconsin glaciation
Wisconsin glaciation
The last glacial period was the most recent glacial period within the current ice age occurring during the last years of the Pleistocene, from approximately 110,000 to 10,000 years ago....
("Würm glaciation" in Europe) was well-advanced; growing ice sheet
Ice sheet
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² , thus also known as continental glacier...
s in North America and Europe displaced the standard climatic zones of the northern hemisphere southward. The temperate zones of Europe and North America acquired an Arctic or tundra
Tundra
In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...
climate, and the rain bands typical of the temperate zones dropped to the latitudes of northern Africa.
Curiously, the same influences that created the Mousterian Pluvial also appear to have brought it to a close. In the period of its fullest development, c. 30 to 18 kybp, the Laurentide ice sheet
Laurentide ice sheet
The Laurentide Ice Sheet was a massive sheet of ice that covered hundreds of thousands of square miles, including most of Canada and a large portion of the northern United States, multiple times during Quaternary glacial epochs. It last covered most of northern North America between c. 95,000 and...
not only covered an enormous geographic area, but increased its altitude to 1750 meters (more than 1 mile). It generated its own long term weather patterns, which affected the jet stream
Jet stream
Jet streams are fast flowing, narrow air currents found in the atmospheres of some planets, including Earth. The main jet streams are located near the tropopause, the transition between the troposphere and the stratosphere . The major jet streams on Earth are westerly winds...
passing over the North American continent. The jet stream effectively split in two, creating a new dominant weather pattern over the northern hemisphere that brought harsher conditions to several regions (including parts of Central Asia
Central Asia
Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north...
and the Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
) — changes that included an end to the Mousterian Pluvial and a return to a more arid climate in northern Africa.