What is an Ice Age?
An Ice Age is a period of time, typically about 30 million but occasionally as long as 300 million years, during which ice sheets cover at least the Earth’s polar areas. Individual Ice Ages have sub-Ice Ages, called glacials (when cold) or interglacials (when warmer) that operate in cycles of 40,000 and 100,000 years. When the term “Ice Age” is used colloquially, it often refers to these shorter glacials, periods when the ice caps extend significantly beyond the poles and into the hearts of continents such as North America and Eurasia. In this sense, “the last Ice Age” refers to what is formally called “the last glacial period”, which began about 70,000 BP and ended between 15,000 and 10,000 BP. This is the Ice Age that was experienced by early man. Scientists cannot say exactly what causes Ice Ages, although there are a number of inter-implicated variables at play. These include atmospheric composition (greenhouse gases), slight changes in the Earth’s orbit known as Milankovitch cycle
An ice age is a period of time usually millions or tens of millions of years when vast glaciers, called ice sheets, cover much of the Earth s land surface. Several ice ages have occurred throughout our planet’s history. The latest ice age began about 2.5 million years ago. During this time, giant ice sheets have advanced and retreated many times in North America and Europe. Recent cycles of advancing and retreating ice sheets have occurred every 100,000 years. Each cycle consists of a long, generally cold period during which the ice sheets slowly reach their maximum extent over tens of thousands of years, and a relatively short warm period during which the ice sheets rapidly retreat. We are now in a warm period that has lasted more than 10,000 years, which is longer than many of the previous warm intervals. If the pattern of glacial cycles still holds true, we should be about due for the beginning of the next cold phase. Indeed, several hundred years ago, global temperatures began decr
What does the term mean when it is capitalized (Ice Age)? When have ice ages occurred, and what has caused them to take place?(Ice ages are periods of time when large areas of Earths surface were covered with ice sheets. The termIce Agerefers to the last major glaciation that occurred in North America and Eurasia, from 2 million to 11,500 years ago, during the Pleistocene period. The movement of Earths plates, reduction of carbon dioxide in the atmosphere, and changes in Earths orbit are three major causes of ice ages.) Ice Ages World BookIce Age • What plants and animals lived during the Ice Age? How do we know about these animals? Give examples of where animal remains have been found and what they have taught scientists.(Many different animals lived during the Ice Age. Among the more interesting are the mastodon, the mammoth, the saber-toothed tiger, the dire wolf, and the snowshoe hare. These animals have been found at several major excavation sites, including La Brea Tar Pits in Lo
An Ice Age is a period of time when large areas of the Earth are covered in ice and snow. These large ice masses are called glaciers. The term “Ice Age” is used in two different contexts. The first is to refer to long and generally cold periods during Earth’s history (tens to hundreds of million years) in which glaciers would advance and retreat. The second is to refer to shorter periods of time in Earth’s history (tens of thousands of years) during which glaciers were near their maximum extent. These shorter intervals are also known as “glaciations.” The term is also used quite commonly to refer to the most recent glaciation in Earth’s history which began about 1.8 million years ago. When the term is used in this sense, the first letter of both words are capitalized. (ie. “Ice Age”).
