jégkorszakokra

Jégkorszakokra, also known as ice ages, are prolonged periods of significant global cooling during which large portions of the Earth's surface are covered by ice sheets and glaciers. These events are characterized by a substantial drop in global temperatures, leading to the expansion of ice masses. The current geological epoch, the Quaternary, is itself an ice age, which began approximately 2.6 million years ago and is marked by cycles of glacial and interglacial periods.

During glacial periods, ice sheets can extend over vast continental areas, reaching latitudes much lower than they do today. This ice accumulation draws significant amounts of water from the oceans, causing sea levels to drop considerably. Interglacial periods are warmer intervals within an ice age, where ice sheets retreat and sea levels rise. The last glacial period ended about 11,700 years ago, marking the beginning of the current interglacial, the Holocene.

The causes of ice ages are complex and involve a combination of factors. Astronomical factors, such as variations in the Earth's orbit (Milankovitch cycles), are believed to be a primary driver, influencing the amount of solar radiation reaching different parts of the planet. Other contributing factors include changes in atmospheric composition, particularly greenhouse gas concentrations, and geological processes like continental drift and volcanic activity. Studying past ice ages provides crucial insights into Earth's climate system and its sensitivity to various influences.