Kelly Robertson
1. Earth is not perfectly round
The diameter of the earth is 7,900 miles from the North Pole through to the South Pole, whereas the diameter of the earth through the equator is 7,926 miles. This slight equatorial bulge is due to the rotation of the earth. Moreover, this bulge is expected to grow larger as the ice caps at the North and South Pole continue to melt, along with glaciers around the world.
2. Days are getting longer
We all know that a day is 24 hours long. However, the length of a day is increasing by 1.7 milliseconds every century, due to the gravitational pull of the moon, causing earth’s rotation to slow down. Some 60 million years ago, an earth day was only 21.6 hours in length.
3. Ice ages
Approximately 800 million years ago, the earth went through several periods of ice ages leaving it looking a like a giant snow ball. Our planet was frozen from North to South Pole with average temperatures of minus 74 degrees Fahrenheit. Science research have discovered that only microscopic and simple cell organisms lived on earth during this period.
4. Driest place on Earth
The Atacama Desert in Northern Chile had only one recorded rainfall in the last 400 years. The desert is so dry that green photosynthetic micro-organisms which live in rocks and under stones cannot be found. On the edge of the desert lies along the Pacific Ocean.
5. Non uniform gravity
Because the earth is not a perfectly smooth sphere, the pull of gravity is not even. Mountain ranges like the Rockies and Himalayas cause positive anomalies, resulting in an increased pull of gravity. On the other hand, deep trenches in the oceans, such as the Marianas Trench, and dips in the earth’s crust caused by large glaciers during ice ages cause negative anomalies and consequently decreased pull of gravity. Other factors include the movement of tectonic plates and movement of the oceans.
