|The physical world of planet earth is constantly evolving as it becomes raised by tectonic plates and forces. Wind, rain and ice also have a large impact on the physical structure of the earth. There are extremes of forces such as floods, landslides, earthquakes and volcanic eruptions, yet the overall change and evolution of the earth's surface changes very gradually over a much longer period of time (i.e. millions of years). The northern hemisphere contains the majority of the earth's landmass and indeed the complete continents of Europe and North America lie within the northern half of the world. In contrast, obviously the southern hemisphere contains more ocean than the north. Australia and Antarctica are continents that lie completely within the southern hemisphere.|
The total mass of planet earth is 5988 million million million tons with a diameter of 12,756 km at the equator. The actual equatorial circumference equates to 40,075 km. The distance from the North to the South Pole is 12,714 km and the total polar circumference of the earth measures 40,008 km. Important geographical features of the world include the Caucasus, Himalayas, Andes mountains and the Rockies. The Java Trench, Bay of Bengal, Mid Atlantic ridge, Alps, Hindu Kush and the Great Lakes are other major features within planet earth.