Stadials and interstadials are phases dividing the

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million year ...

period, or the last 2.6 million years. Stadials are periods of colder climate while interstadials are periods of warmer climate. Each Quaternary climate phase is associated with a

Marine Isotope Stage Marine isotope stages (MIS), marine oxygen-isotope stages, or oxygen isotope stages (OIS), are alternating warm and cool periods in the Earth's paleoclimate, deduced from oxygen isotope data reflecting changes in temperature derived from data f ...

(MIS) number, which describe alternation between warmer and cooler temperatures as measured by oxygen isotope data. Stadials have even MIS numbers and interstadials odd MIS numbers. The current

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...

interstadial is MIS 1 and the

Last glacial maximum The Last Glacial Maximum (LGM), also referred to as the Late Glacial Maximum, was the most recent time during the Last Glacial Period that ice sheets were at their greatest extent. Ice sheets covered much of Northern North America, Northern Eu ...

stadial is MIS 2. Marine Isotope Stages are sometimes further subdivided into stadials and interstadials by minor climate fluctuations within the overall stadial or interstadial regime, which are indicated by letters. The odd-numbered interstadial

MIS 5 Marine Isotope Stage 5 or MIS 5 is a marine isotope stage in the geologic temperature record, between 130,000 and 80,000 years ago. Sub-stage MIS 5e, called the Eemian or Ipswichian, covers the last major interglacial period before the Holocene, w ...

, also known as the

Sangamonian The Sangamonian Stage (or Sangamon interglacial) is the term used in North America to designate the last interglacial period. In its most common usage, it is used for the period of time between 75,000 and 125,000 BP.Willman, H.B., and J.C. Frye, ...

interglacial, contains two periods of relative cooling, and so is subdivided into three interstadials (5a, 5c, 5e) and two stadials (5b, 5d). A stadial isotope stage like MIS 6 would be subdivided by periods of relative warming, and so in that case the first and last subdivisions would be stadials; MIS 6a, 6c and 6e are stadials while 6b and 6d are interstadials.

Distinction between stadials and glacials

Generally, stadials endure for a thousand years or less, and interstadials for less than ten thousand years, while

interglacial An interglacial period (or alternatively interglacial, interglaciation) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene i ...

s last for more than ten thousand and

glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...

s for about one hundred thousand. In order for a period to be considered an interglacial, it changes from Arctic through sub-Arctic to boreal to temperate conditions and back again. An interstadial will only reach the stage of boreal vegetation. While the MIS 1 interstadial encompasses the entirety of the present Holocene interglacial, the

Wisconsin glaciation The Wisconsin Glacial Episode, also called the Wisconsin glaciation, was the most recent glacial period of the North American ice sheet complex. This advance included the Cordilleran Ice Sheet, which nucleated in the northern North American Cord ...

encompasses MIS 2, 3, and 4. Glacials and Interglacials refer to the 100kyr cycles associated with

Milankovitch cycles Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The term was coined and named after Serbian geophysicist and astronomer Milutin Milanković. In the 1920s, he hypot ...

, while stadials and interstadials are defined by the actual oxygen-isotope temperature record.

List of stadials and interstadials

Bølling/Allerød interstadial

The

Bølling oscillation The Bølling oscillation, also Bølling interstadial, was a cool temperate climatic interstadial between the glacial Oldest Dryas and Older Dryas stadials, between 14,700 and 14,100 BP, near to the end of the last glacial period. It is named aft ...

and the

Allerød oscillation The Allerød oscillation ( da, Allerødtiden) was a warm and moist global interstadial that occurred c.13,900 to 12,900 BP, nearly at the end of the Last Glacial Period. It raised temperatures in the northern Atlantic region to almost present-da ...

, where they are not clearly distinguished in the

stratigraphy Stratigraphy is a branch of geology concerned with the study of rock layers ( strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...

, are taken together to form the Bølling/Allerød interstadial, and dated from about 14,700 to 12,700 years before the present.

Dryas Periods

The Oldest, Older, and

Younger Dryas The Younger Dryas (c. 12,900 to 11,700 years BP) was a return to glacial conditions which temporarily reversed the gradual climatic warming after the Last Glacial Maximum (LGM, c. 27,000 to 20,000 years BP). The Younger Dryas was the last stag ...

are three stadials that occurred during the warming since the

Last Glacial Maximum The Last Glacial Maximum (LGM), also referred to as the Late Glacial Maximum, was the most recent time during the Last Glacial Period that ice sheets were at their greatest extent. Ice sheets covered much of Northern North America, Northern Eu ...

. The Older Dryas occurred between the Bølling and Allerød interstadials. All three periods are named for the arctic plant species,

Dryas octopetala ''Dryas octopetala'', the mountain avens, eightpetal mountain-avens, white dryas or white dryad, is an Arctic–alpine flowering plant in the family Rosaceae. It is a small prostrate evergreen subshrub forming large colonies. The specific epithe ...

, which proliferated during these cold periods.

Dansgaard-Oeschger events

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland ...

ice core An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ...

s show 24 interstadials during the one hundred thousand years of the Wisconsin glaciation. Referred to as the Dansgaard-Oeschger events, they have been extensively studied, and in their northern European contexts are sometimes named after towns, such as the Brorup, the Odderade, the

Oerel Oerel is a municipality in the district of Rotenburg, in Lower Saxony, Germany. Oerel belonged to the Prince-Archbishopric of Bremen, established in 1180. In 1648 the Prince-Archbishopric was transformed into the Duchy of Bremen, which was firs ...

, the Glinde, the Hengelo, or the

Denekamp Denekamp () is a town in the Dutch province of Overijssel. It is a part of the region of Twente and the municipality of Dinkelland, and lies about 9 km northeast of Oldenzaal. The town was first noted as early as the 10th century when it wa ...

References