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The natural history of Earth concerns the development of planet Earth from its formation to the present day. [ 1 ] [ 2 ] Nearly all branches of natural science have contributed to understanding of the main events of Earth's past, characterized by constant geological change and biological evolution .
The mass of Earth's oceans is estimated to be 1.37 × 10 21 kg, which is 0.023% of the total mass of Earth, 6.0 × 10 24 kg. An additional 5.0 × 10 20 kg of water is estimated to exist in ice, lakes, rivers, groundwater, and atmospheric water vapor. [21] A significant amount of water is also stored in Earth's crust, mantle, and core.
This demonstrates the crustal spatial evolution at the Earth's surface dictated by plate tectonics. Earth's crustal evolution involves the formation, destruction and renewal of the rocky outer shell at that planet's surface. The variation in composition within the Earth's crust is much greater than that of other terrestrial planets.
Pangaea straddled the equator and extended toward the poles, with a corresponding effect on ocean currents in the single great ocean (Panthalassa, the universal sea), and the Paleo-Tethys Ocean, a large ocean that was between Asia and Gondwana. The Cimmeria continent rifted away from Gondwana and drifted north to Laurasia, causing the Paleo ...
The ocean is a major driver of Earth's water cycle. Ocean water represents the largest body of water within the global water cycle (oceans contain 97% of Earth's water). Evaporation from the ocean moves water into the atmosphere to later rain back down onto land and the ocean. [69] Oceans have a significant effect on the biosphere.
By the start of the Carboniferous Period, the Earth begins to resemble its present state. Insects roamed the land and would soon take to the skies; sharks swam the oceans as top predators, [83] and vegetation covered the land, with seed-bearing plants and forests soon to flourish.
The history of life on Earth traces the processes by which living and extinct organisms evolved, from the earliest emergence of life to the present day. Earth formed about 4.5 billion years ago (abbreviated as Ga, for gigaannum) and evidence suggests that life emerged prior to 3.7 Ga. [1] [2] [3] The similarities among all known present-day species indicate that they have diverged through the ...
Most of Earth's surface is ocean water: 70.8% or 361 million km 2 (139 million sq mi). [97] This vast pool of salty water is often called the world ocean, [98] [99] and makes Earth with its dynamic hydrosphere a water world [100] [101] or ocean world. [102] [103] Indeed, in Earth's early history the ocean may have covered Earth completely. [104]