EVERYDAY SCIENCE

SCIENCE

EARTH SCIENCE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Which of the following has caused repeating 100, 000-year cycles of ice ages in the past?
A
an increase in sun spots
B
several major volcanic eruptions
C
changes in Earth’s orbit and the tilt of its axis
D
continental drift
Explanation: 

Detailed explanation-1: -The answer is that the 100, 000-year orbital cycle modulates the effects of the precession cycle. The 100, 000-year cycle deals with the eccentricity of Earth’s orbit-meaning the extent to which it deviates from a circle.

Detailed explanation-2: -BERKELEY, CA–Recent ice ages–ten periods of glaciation in the past million years–are caused by changes in the tilt of the Earth’s orbit, according to research published in the July 11 issue of Science magazine.

Detailed explanation-3: -A likely reason could be a phenomenon called Milankovitch cycles–cyclic changes in Earth’s orbit and orientation toward the Sun that affect the amount of energy Earth absorbs. That, scientists agree, has been the main natural driver of alternating warm and cold periods for millions of years.

Detailed explanation-4: -New research suggests that our oceans might regularly suck more CO2 out of the atmosphere every 100, 000 years, allowing the planet to get cold enough to trigger an ice age.

Detailed explanation-5: -Over thousands of years, the amount of sunshine reaching Earth changes by quite a lot, particularly in the northern latitudes, the area near and around the North Pole. When less sunlight reaches the northern latitudes, temperatures drop and more water freezes into ice, starting an ice age.

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