Quaternary glaciation in the context of "Hortobágy National Park"

The continent of Australia, sometimes known in technical contexts as Sahul (/səˈhuːl/), Australia-New Guinea, Australinea, or Meganesia to distinguish it from the country of Australia, is located within the Southern and Eastern hemispheres, near the Maritime Southeast Asia. The continent includes mainland Australia, Tasmania, the island of New Guinea (Papua New Guinea and Western New Guinea), the Aru Islands, the Ashmore and Cartier Islands, most of the Coral Sea Islands, and some other nearby islands. Situated in the geographical region of Oceania, more specifically in the subregion of Australasia, Australia is the smallest of the seven traditional continents.

The continent includes a continental shelf overlain by shallow seas which divide it into several landmasses—the Arafura Sea and Torres Strait between mainland Australia and New Guinea, and Bass Strait between mainland Australia and Tasmania. When sea levels were lower during the Pleistocene ice age, including the Last Glacial Maximum about 18,000 BC, they were connected by dry land into the combined landmass of Sahul. The name "Sahul" derives from the Sahul Shelf, which is a part of the continental shelf of the Australian continent. During the past 18,000 to 10,000 years, rising sea levels overflowed the lowlands and separated the continent into today's low-lying arid to semi-arid mainland and the two mountainous islands of New Guinea and Tasmania. With a total land area of 8.56 million square kilometres (3,310,000 sq mi), the Australian continent is the smallest, lowest, flattest, and second-driest continent (after Antarctica) on Earth. As the country of Australia is mostly on a single landmass, and comprises most of the continent, it is sometimes informally referred to as an island continent, surrounded by oceans.

The Last Glacial Period (LGP), also known as the last glacial cycle, occurred from the end of the Last Interglacial to the beginning of the Holocene, c. 115,000 – c. 11,700 years ago, and thus corresponds to most of the timespan of the Late Pleistocene. It thus formed the most recent period of what is colloquially known as the "Ice Age".

The LGP is part of a larger sequence of glacial and interglacial periods known as the Quaternary glaciation which started around 2,588,000 years ago and is ongoing. The glaciation and the current Quaternary Period both began with the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Mya (million years ago), in the mid-Cenozoic (Eocene–Oligocene extinction event), and the term Late Cenozoic Ice Age is used to include this early phase with the current glaciation. The previous ice age within the Quaternary is the Penultimate Glacial Period, which ended about 128,000 years ago, was more severe than the Last Glacial Period in some areas such as Britain, but less severe in others.

The British Isles are an archipelago in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles (Orkney and Shetland), and over six thousand smaller islands. They have a total area of 315,159 km (121,684 sq mi) and a combined population of almost 75 million, and include two sovereign states, the Republic of Ireland (which covers roughly five-sixths of Ireland) and the United Kingdom of Great Britain and Northern Ireland. The Channel Islands, off the north coast of France, are normally taken to be part of the British Isles, even though geographically they do not form part of the archipelago. Under the UK Interpretation Act 1978, the Channel Islands are clarified as forming part of the British Islands, not to be confused with the British Isles.

The oldest rocks are 2.7 billion years old and are found in Ireland, Wales and the north-west of Scotland. During the Silurian period, the north-western regions collided with the south-east, which had been part of a separate continental landmass. The topography of the islands is modest in scale by global standards. Ben Nevis, the highest mountain, rises to only 1,345 metres (4,413 ft), and Lough Neagh, which is notably larger than other lakes in the island group, covers 390 square kilometres (151 sq mi). The climate is temperate marine, with cool winters and warm summers. The North Atlantic drift brings significant moisture and raises temperatures 11 °C (20 °F) above the global average for the latitude. This led to a landscape that was long dominated by temperate rainforest, although human activity has since cleared the vast majority of forest cover. The region was re-inhabited after the last glacial period of Quaternary glaciation, by 12,000 BC, when Great Britain was still part of a peninsula of the European continent. Ireland was connected to Great Britain by the British-Irish Ice Sheet before 14,000 BC, and was not inhabited until after 8000 BC. Great Britain became an island by 7000 BC with the flooding of Doggerland.

It is believed that the peopling of the Americas began when Paleolithic hunter-gatherers (Paleo-Indians) entered North America from the North Asian Mammoth steppe via the Beringia land bridge, which had formed between northeastern Siberia and western Alaska due to the lowering of sea level during the Last Glacial Maximum (26,000 to 19,000 years ago). These populations expanded south of the Laurentide Ice Sheet, either by sea or land, and spread rapidly southward, occupying both North and South America no later than 14,000 years ago, and possibly before 20,000 years ago. The earliest populations in the Americas, before roughly 10,000 years ago, are known as Paleo-Indians. Indigenous peoples of the Americas have been linked to Siberian populations by proposed linguistic factors, the distribution of blood types, and in genetic composition as reflected by molecular data, such as DNA.

While there is general agreement that the Americas were first settled from Asia, the pattern of migration and the place(s) of origin in Eurasia of the peoples who migrated to the Americas remain unclear. The most generally accepted theory is that Ancient Beringians moved when sea levels were significantly lowered due to the Quaternary glaciation, following herds of now-extinct Pleistocene megafauna along ice-free corridors that stretched between the Laurentide and Cordilleran ice sheets. Another proposed route has them migrating down the Pacific coast to South America as far as Chile, either on foot or using boats. Any archaeological evidence of coastal occupation during the last Ice Age would now have been covered by the sea level rise, up to a hundred metres since then.

The Quaternary (/kwəˈtɜːrnəri/ kwə-TUR-nər-ee, US also /ˈkwɒtərnɛri/ KWOT-ər-nerr-ee) 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), as well as the current and most recent of the twelve periods of the Phanerozoic eon. It follows the Neogene Period and spans from 2.6 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene (2.6 million years ago to 12 thousand years ago) and the Holocene (12 thousand years ago to today); a proposed third epoch, the Anthropocene, was rejected in 2024 by IUGS, the governing body of the ICS.

The Quaternary is typically defined by the Quaternary glaciation, the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused.

Lake Tahoe (/ˈtɑːhoʊ/) is a freshwater lake in the Sierra Nevada of the Western United States, straddling the border between California and Nevada. Lying at 6,225 ft (1,897 m) above sea level, Lake Tahoe is the largest alpine lake in North America, and at 122,160,280 acre⋅ft (150.7 km) it trails only the five Great Lakes as the largest by volume in the United States. Its depth is 1,645 ft (501 m), making it the second deepest in the United States after Crater Lake in Oregon (1,949 ft or 594 m).

The lake was formed about two million years ago as part of the Lake Tahoe Basin, and its modern extent was shaped during the ice ages. It is known for the clarity of its water and the panorama of surrounding mountains on all sides. The area surrounding the lake is also referred to as Lake Tahoe, or simply Tahoe; its English name is derived from its Washo name, Dáʔaw. More than 75% of the lake's watershed is national forest land, covered by the Lake Tahoe Basin Management Unit of the United States Forest Service.

An ice age is a term describing periods of time when the reduction in the temperature of Earth's surface and atmosphere results in the presence or expansion of continental and polar ice sheets and alpine glaciers. The term is applied in several different senses to very long and comparatively short periods of cooling. Colder periods are called glacials or ice ages, and warmer periods are called interglacials.

Earth's climate alternates between icehouse and greenhouse periods based on whether there are glaciers on the planet, and for most of Earth's history it has been in a greenhouse period with little or no permanent ice. Over the very long term, Earth is currently in an icehouse period called the Late Cenozoic Ice Age, which started 34 million years ago. There have been colder and warmer periods within this ice age, and the term is also applied to the Quaternary glaciation, which started 2.58 million years ago. Within this period, the Last Interglacial ended 115,000 years ago, and was followed by the Last Glacial Period (LGP), which gave way to the current warm Holocene, which started 11,700 years ago. The most severe cold period of the LGP was the Last Glacial Maximum, which reached its maximum between 26,000 and 20,000 years ago. The most recent glaciation was the Younger Dryas between 12,800 and 11,700 years ago