Background color for WARNING safety signs, labels, and tags. Marking hazardous parts of machines with may cut, crush, or otherwise injure. Emphasizing hazards when enclosure doors are open or when gear, belt, or other guards around moving equipment are opened or removed, exposing unguarded hazards. Marking exposed edges of
Bibcode:1995GBioC...9..377C. doi:10.1029/95GB01107. An ice age is a period of long-term reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers.
Quick Answer. According to ScienceDaily, ice ages occur every 100,000 years. They are made up of extremely cold periods, glacials, during which thick ice sheets bury vast areas of North America, Europe and Asia, and warm periods, interglacials, when the ice melts. Continue Reading.