"Channel Scablands sometime before 1.5 million years ago. Because of the fragmentary nature of older glaciofluvial deposits, which have been largely removed by subsequent Missoula floods, the exact number of older Missoula floods, which are known as ""Ancient Cataclysmic Floods"", that occurred during the Pleistocene cannot be estimated with any confidence. As many as 100 separate, cataclysmic Ice Age floods may have occurred during the last glaciation. There have been at least 17 complete interglacial-glacial cycles since about 1.77 million years ago, and perhaps as many as 44 interglacial-glacial cycles since the beginning of the Pleistocene about 2.58 million years"
"Timeline of glaciation There have been five or six major ice ages in the history of Earth over the past 3 billion years. The Late Cenozoic Ice Age began 34 million years ago, its latest phase being the Quaternary glaciation, in progress since 2.58 million years ago. Within ice ages, there exist periods of more severe glacial conditions and more temperate referred to as glacial periods and interglacial periods, respectively. The Earth is currently in such an interglacial period of the Quaternary glaciation, with the last glacial period of the Quaternary having ended approximately 11,700 years ago, the current interglacial"
"present pattern of ice ages began about , then intensified at the end of the Pliocene. The polar regions have since undergone repeated cycles of glaciation and thaw, repeating every 40,000–100,000 years. The last glacial period of the current ice age ended about 10,000 years ago. The Precambrian includes approximately 90% of geologic time. It extends from 4.6 billion years ago to the beginning of the Cambrian Period (about 541 Ma). It includes three eons, the Hadean, Archean, and Proterozoic. Major volcanic events altering the Earth's environment and causing extinctions may have occurred 10 times in the past 3 billion"
"glaciation. Some modern authors use the traditional regional glacial names to identify such a sequence of glaciations, whereas others replace the word “glaciation” with “complex” to refer to a continuous period of time that also includes warmer stages. As shown in the table below, it is only during the last 200-300 thousand years that the time resolution of the traditional nomenclature allow for direct correspondence with MIS indexes. For sources to the tables, see the individual linked articles. Timeline of glaciation There have been five or six major ice ages in the history of Earth over the past 3 billion"
"as evidenced most clearly by ice cores for the past 800,000 years and marine sediment cores for the earlier period. Over the past 740,000 years there have been eight glacial cycles. The entire Quaternary Period, starting 2.58 Ma, is referred to as an ice age because at least one permanent large ice sheet—the Antarctic ice sheet—has existed continuously. There is uncertainty over how much of Greenland was covered by ice during each interglacial. Currently, Earth is in an interglacial period, which marked the beginning of the Holocene epoch. The current interglacial began between 15,000 and 10,000 years ago; this caused"
"commenced with Greenland becoming increasingly covered by an ice sheet in late Pliocene (2.9-2.58 Ma ago). The evolution of the Paranthropus occurred 2.7 million years ago. 2.58 million years ago was the official start of the Pleistocene Glaciation, the current phase of the Late Cenozoic Ice Age. Throughout the Pleistocene, there have been glacial periods (cold periods with extended glaciation) and interglacial periods (warm periods with less glaciation). The term stadial is a rough equivalent of the term glacial period. And interstadial is a rough equivalent of the term interglacial period. The oscillation between glacial and interglacial periods is due"
"ages for the past 2.2–2.1 million years (starting before the Quaternary in the late Neogene Period). Note in the graphic on the right the strong 120,000-year periodicity of the cycles, and the striking asymmetry of the curves. This asymmetry is believed to result from complex interactions of feedback mechanisms. It has been observed that ice ages deepen by progressive steps, but the recovery to interglacial conditions occurs in one big step. The graph on the left shows the temperature change over the past 12,000 years, from various sources. The thick black curve is an average. The climate forcing is the"
"characterized by cycles of glacials and interglacials within a gradually deepening ice age. Currently, the Earth is in an interglacial period, beginning about 20,000 years ago (20 kya). The cycles of glaciation involve the growth and retreat of continental ice sheets in the Northern Hemisphere and involve fluctuations on a number of time scales, notably on the 21 ky, 41 ky and 100 ky scales. Such cycles are usually interpreted as being driven by predictable changes in the Earth orbit known as Milankovitch cycles. At the beginning of the Middle Pleistocene (0.8 million years ago, close to the Brunhes–Matuyama geomagnetic"
"of an even longer ice age called the Late Cenozoic Ice Age. It began 33.9 million years ago and is also ongoing. It began with the formation of the Antarctic Ice Cap. Just like the Last Glacial Period, the penultimate glacial period has no name. The word ""penultimate"" means second to last. The penultimate glacial period was at least the second glacial period that ""Neanderthals"" and ""Homo sapiens"" experienced. Penultimate Glacial Period was more severe than the Last Glacial Period. Penultimate Glacial Period The Penultimate Glacial Period (PGP) is the glacial period that occurred before the last glacial period. It"
"age that the planet is currently in and has been in for the last 2.58 million years. It is the time period in which the arctic ice sheets have existed. The Pleistocene Ice Age is part of an even longer ice age called the Late Cenozoic Ice Age, which began 33.9 million years ago and is ongoing. It is the time period in which the Antarctic ice cap has existed. The Vashon Glaciation lasted from about 19,000 - 16,000 BP (Before Present - present defined as January 1, 1950 for this scale). The Cordilleran Ice Sheet was an ice sheet"
"already be an unusually long warm period. Projection of the timeline for the next glacial maximum depend crucially on the amount of in the atmosphere. Models assuming increased levels at 750 parts per million (ppm; current levels are at 407 ppm) have estimated the persistence of the current interglacial period for another 50,000 years. Quaternary glaciation The Quaternary glaciation, also known as the Quaternary Ice Age or Pleistocene glaciation, is a series of glacial events separated by interglacial events during the Quaternary period that began 2.58 Ma (million years ago), and is ongoing. It is one of five major glacial"
"Quaternary glaciation The Quaternary glaciation, also known as the Quaternary Ice Age or Pleistocene glaciation, is a series of glacial events separated by interglacial events during the Quaternary period that began 2.58 Ma (million years ago), and is ongoing. It is one of five major glacial periods or ""ice ages"" in Earth's history since about 2.5 billion years ago; the preceding one, known as the Karoo Ice Age, lasted from about 360 to 260 Ma (Carboniferous to Mid-Permian). Outside of these ice ages, the Earth seems to have been completely ice-free, even at high latitudes. The definition of the Quaternary"
"current ice age began 2.6 million years ago at the start of the Pleistocene epoch, and the Greenland, Arctic, and Antarctic ice sheets still exist. In 1742, Pierre Martel (1706–1767), an engineer and geographer living in Geneva, visited the valley of Chamonix in the Alps of Savoy. Two years later he published an account of his journey. He reported that the inhabitants of that valley attributed the dispersal of erratic boulders to the glaciers, saying that they had once extended much farther. Later similar explanations were reported from other regions of the Alps. In 1815 the carpenter and chamois hunter"
"last another 50,000 years. Glacial period 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 between glacial periods. The last glacial period ended about 15,000 years ago. The Holocene epoch is the current interglacial. A time when there are no glaciers on Earth is considered a greenhouse climate state. Within the Quaternary glaciation (2.6 Ma to present), there have been a number of glacials and interglacials. The last glacial period was"
"Glacial period 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 between glacial periods. The last glacial period ended about 15,000 years ago. The Holocene epoch is the current interglacial. A time when there are no glaciers on Earth is considered a greenhouse climate state. Within the Quaternary glaciation (2.6 Ma to present), there have been a number of glacials and interglacials. The last glacial period was the most recent glacial"
"interglacial. Whilst the large-scale signals from the cores are clear, there are problems interpreting the detail, and connecting the isotopic variation to the temperature signal. On longer time scales, sediment cores show that the cycles of glacials and interglacials are part of a deepening phase within a prolonged ice age that began with the glaciation of Antarctica approximately 40 million years ago. This deepening phase, and the accompanying cycles, largely began approximately 3 million years ago with the growth of continental ice sheets in the Northern Hemisphere. Gradual changes in Earth's climate of this kind have been frequent during the"
"current extent. It has persisted to the current time. In the last three million years, glaciations have spread to the northern hemisphere. It commenced with Greenland becoming increasingly covered by an ice sheet in late Pliocene (2.9-2.58 Ma ago) During the Pleistocene Epoch (starting 2.58 Ma ago), the Pleistocene Glaciation developed with decreasing mean temperatures and increasing amplitudes between glacials and interglacials. During the glacial periods of the Pleistocene, large areas of northern North America and northern Eurasia have been covered by ice sheets. Throughout the Phanerozoic Aeon (everything after the Precambrian), the Earth has altered between two phases, greenhouse"
"Monitoring Service collects data annually on glacier retreat and glacier mass balance. From this data, glaciers worldwide have been found to be shrinking significantly, with strong glacier retreats in the 1940s, stable or growing conditions during the 1920s and 1970s, and again retreating from the mid-1980s to the present. The most significant climate processes since the middle to late Pliocene (approximately 3 million years ago) are the glacial and interglacial cycles. The present interglacial period (the Holocene) has lasted about 11,700 years. Shaped by orbital variations, responses such as the rise and fall of continental ice sheets and significant sea-level"
"Late Cenozoic Ice Age The Late Cenozoic Ice Age, Holarctic-Antarctic Ice Age or Antarctic Glaciation began 33.9 million years ago at the Eocene-Oligocene Boundary and is ongoing. It is Earth's current ice age or icehouse period. Its beginning is marked by the formation of the Antarctic ice sheets. The Late Cenozoic Ice Age gets its name due to the fact that it covers roughly the last half of Cenozoic Era so far. Six million years after the start of the Late Cenozoic Ice Age, the East Antarctic Ice Sheet had formed, and 14 million years ago it had reached its"
"sheet advances does not correlate automatically with the farthest extent of the Scandinavian ice sheet. In North America the corresponding ""last ice age"" is called the Wisconsin glaciation. In the Gelasian, i.e. at the beginning of the Quaternary period around 2.6 million years ago, an ice age began in the northern hemisphere which continues today. Characteristic of such ice ages is the glaciation of the polar caps. After the Gelasian followed the Early, Middle and Late Pleistocene with a succession of several warm and cold periods. The latter are often called ""ice ages"" or ""glacials"", the former term often being"
"Penultimate Glacial Period The Penultimate Glacial Period (PGP) is the glacial period that occurred before the last glacial period. It began ~194,000 years ago, and ended 135,000 years ago with the beginning of the Eemian interglacial. It roughly coincides with Marine Isotope Stage 6 (see Marine Isotope Stage) and the Illinoian Stage. The penultimate glacial period is one of a series of glacial and interglacial periods of the Quaternary Ice Age/Quaternary Glaciation. The Quaternary Ice Age began 2.58 million years ago and is ongoing. It began with the formation of the Arctic Ice Cap. The Quaternary Ice Age is part"
"glaciation occurred from the Pleistocene Epoch (1.8 million – 70,000 years ago) to the Holocene Epoch (fewer than 11,000 years ago). These ice ages left their mark on the Rockies, forming extensive glacial landforms, such as U-shaped valleys and cirques. Recent glacial episodes included the Bull Lake Glaciation, which began about 150,000 years ago, and the Pinedale Glaciation, which perhaps remained at full glaciation until 15,000–20,000 years ago. All of these geological processes exposed a complex set of rocks at the surface. For example, volcanic rock from the Paleogene and Neogene periods (66 million – 2.6 million years ago) occurs"
"current ice age, which occurred during the last years of the Pleistocene era. The Ice Age reached its peak during the Last Glacial Maximum, when ice sheets began advancing from 33,000YBP and reached their maximum limits 26,500YBP. Deglaciation commenced in the Northern Hemisphere approximately 19,000YBP and in Antarctica approximately 14,500 yearsYBP, which is consistent with evidence that glacial meltwater was the primary source for an abrupt rise in sea level 14,500YBP and the bridge was finally inundated around 11,000 YBP. The fossil evidence from many continents points to the extinction of large animals, termed Pleistocene megafauna, near the end of"
"year-round ice according to the USGS. The current sea level (as of 2009) is 70 meters (230 feet) lower than it would be without the ice sheets of Antarctica and Greenland. Late Cenozoic Ice Age The Late Cenozoic Ice Age, Holarctic-Antarctic Ice Age or Antarctic Glaciation began 33.9 million years ago at the Eocene-Oligocene Boundary and is ongoing. It is Earth's current ice age or icehouse period. Its beginning is marked by the formation of the Antarctic ice sheets. The Late Cenozoic Ice Age gets its name due to the fact that it covers roughly the last half of Cenozoic"
"period within the Quaternary glaciation of the Current Ice Age, occurring in the Pleistocene epoch, which began about 110,000 years ago and ended about 15,000 years ago. The glaciations that occurred during this glacial period covered many areas of the Northern Hemisphere and have different names, depending on their geographic distributions: ""Wisconsin"" (in North America), ""Devensian"" (in Great Britain), ""Midlandian"" (in Ireland), ""Würm"" (in the Alps), ""Weichsel"" (in northern central Europe), ""Dali"" (in East China), ""Beiye"" (in North China), ""Taibai"" (in Shaanxi) ""Luojishan"" (in Southwest Sichuan), ""Zagunao"" (in Northwest Sichuan), ""Tianchi"" (in Tianshan Mountains) ""Qomolangma"" (in Himalaya), and ""Llanquihue"" (in"
"glacial period ended about 11,500 years ago. Since then, Earth has been in an interglacial period called the Holocene. The major glacial stages of the current ice age in North America are the Illinoian, Eemian and Wisconsin glaciation. The use of the Nebraskan, Afton, Kansan, and Yarmouthian stages to subdivide the ice age in North America has been discontinued by Quaternary geologists and geomorphologists. These stages have all been merged into the Pre-Illinoian in the 1980s. During the most recent North American glaciation, during the latter part of the Last Glacial Maximum (26,000 to 13,300 years ago), ice sheets extended"
"probably contributed to periods with highest overall temperatures. One suggested explanation of the Paleocene-Eocene Thermal Maximum is that undersea volcanoes released methane from clathrates and thus caused a large and rapid increase in the greenhouse effect. There appears to be no geological evidence for such eruptions at the right time, but this does not prove they did not happen. The current ice age, called the Quaternary glaciation, which began 2.6 million years ago and extends into the present, has seen more or less extensive glaciation on 40,000 and later, 100,000 year cycles. The interglacials lasted about 10,000–20,000 years. The last"
"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 interglacial began at the end of the Pleistocene, about 11,700 years ago. During the 2.5 million year span of the Pleistocene, numerous glacials, or significant advances of continental ice sheets in North America and Europe, have occurred at intervals of approximately 40,000 to 100,000 years. These long glacial periods were separated by more temperate and shorter interglacials. During interglacials, such as the present one, the climate warms"
"scales called glacial periods, glacials or glacial advances, and interglacial periods, interglacials or glacial retreats. The earth is currently in an interglacial, and the last glacial period ended about 10,000 years ago. All that remains of the continental ice sheets are the Greenland and Antarctic ice sheets and smaller glaciers such as on Baffin Island. The definition of the Quaternary as beginning 2.58 Ma is based on the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Ma, in the mid-Cenozoic (Eocene-Oligocene Boundary). The term Late Cenozoic Ice Age is used to"
"Last Glacial Period The Last Glacial Period (LGP) occurred from the end of the Eemian interglacial to the end of the Younger Dryas, encompassing the period years ago. This most recent glacial period is part of a larger pattern of glacial and interglacial periods known as the Quaternary glaciation extending from years ago to present. The definition of the Quaternary as beginning 2.58 Ma is based on the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Ma, in the mid-Cenozoic (Eocene–Oligocene extinction event). The term Late Cenozoic Ice Age is used"
"the most severe ice ages in its history during this period (Sturtian and Marinoan). According to Eyles and Young, ""Late Proterozoic glaciogenic deposits are known from all the continents. They provide evidence of the most widespread and long-ranging glaciation on Earth."" Several glacial periods are evident, interspersed with periods of relatively warm climate, with glaciers reaching sea level in low paleolatitudes. Glaciers extended and contracted in a series of rhythmic pulses, possibly reaching as far as the equator. The Cryogenian is generally considered to be divisible into at least two major worldwide glaciations. The Sturtian glaciation persisted from 720 to"
"of multiple advances and retreats of the ice. Even before the theory of worldwide glaciation was generally accepted, many observers recognized that more than a single advance and retreat of the ice had occurred. Since then, other, earlier ice ages have been identified, and the Quaternary event(s) constrained. The Current or Quaternary Ice Age is the last of five known major glacial periods, or ice ages, during Earth's history, the preceding ones being the Karoo Ice Age (360–260 Ma), Andean-Saharan (450–420 Ma), Cryogenian (720–635 Ma) and Huronian (2,400–2,100 Ma). Within the Quaternary Period, or ice age, there were also periodic"
"of the environment. Similarly, the dire wolf was a hypercarnivore, with a skull and dentition adapted for hunting large and struggling prey; the shape of its skull and snout changed across time, and changes in the size of its body have been correlated to climate fluctuations. The last glacial period, commonly referred to as the ""Ice Age"", spanned 125,000–14,500YBP and was the most recent glacial period within the current ice age, which occurred during the last years of the Pleistocene era. The Ice Age reached its peak during the Last Glacial Maximum, when ice sheets began advancing from 33,000YBP and"