When Is The Ice Age?
Introduction
The Ice Age is a geological period characterized by a significant drop in temperature the expansion of ice sheets across the Earth’s surface. This article aims to provide an overview of when the Ice Age occurred the main factors contributing to its various periods.
Ice Age Periods
The Earth’s history has witnessed several Ice Age periods with the most recent one being called the Pleistocene Ice Age. This period started around 2.6 million years ago lasted until approximately 11700 years ago.
The Last Glacial Period
Within the Pleistocene Ice Age there were several glacial interglacial periods. The most recent glacial period commonly referred to as the Last Glacial Period occurred between 110000 11700 years ago.
Effects of the Last Glacial Period
During the Last Glacial Period vast ice sheets covered much of North America Europe Asia. These ice sheets reached their maximum extent around 21000 years ago resulting in lower sea levels due to the amount of water trapped in the ice. The lower sea levels exposed lbridges such as the Bering LBridge linking Siberia with Alaska allowing human animal migrations.
Causes of the Ice Age
The primary cause of the Ice Age including the Pleistocene Ice Age is attributed to variations in Earth’s orbit axial tilt referred to as Milankovitch cycles. These cycles affect the amount distribution of solar radiation reaching the Earth’s surface leading to changes in climate.
Milankovitch Cycles
There are three main cycles involved in the Milankovitch theory – eccentricity axial tilt precession. Eccentricity is the variation in the Earth’s orbit from a perfect circle to an elliptical shape occurring in cycles of approximately 100000 years. Axial tilt refers to the tilt of the Earth’s axis which varies between 22.1 24.5 degrees over a cycle of about 41000 years. Precession involves the gradual shift of the Earth’s axis orientation in a cycle of approximately 26000 years.
Combined Effect
These cycles interact influence the distribution intensity of solar radiation received by the Earth. When these cycles align in a specific way such as a decrease in axial tilt combined with a more elliptical orbit they contribute to the onset of an Ice Age.
Conclusion
The Ice Age specifically the Pleistocene Ice Age took place between 2.6 million 11700 years ago with the Last Glacial Period being the most recent glacial phase. The primary causes of the Ice Age are variations in Earth’s orbit axial tilt known as Milankovitch cycles. These cycles influence the amount of solar radiation reaching the Earth’s surface leading to substantial changes in climate the expansion of ice sheets. Understanding the Ice Age its causes provides valuable insights into Earth’s geological history the impact of natural climate variations.
