What is the Geosphere?

Any of the almost spherical concentric regions of matter that make up the earth and its atmosphere, as the lithosphere and hydrosphere. The geosphere includes the rocks and minerals on Earth – from the molten rock and heavy metals in the deep interior of the planet to the sand on beaches and peaks of mountains. The geosphere also includes the abiotic (non-living) parts of soils, and the skeletons of animals that may become fossilized over geologic time.

The geosphere is the earth itself: the rocks, minerals, and landforms of the surface and interior. Below the crust - which varies in depth from about 5 km beneath the ocean floor to up to 70 km below the land surface, temperatures are high enough for deformation and a paste-like flow of elements. At one time, roughly 200 million years ago, the continents were joined together in a supercontinent called Pangaea, but since then tectonic plates have slowly separated, creating the arrangement of the continents we are accustomed to today.

The top layer of the geosphere is the crust. There is oceanic crust (4-9 km thick) and the continental crust (30-70 km thick). The crust is less than one percent of the Earth’s volume. The Earth’s tectonic plates are located beneath the crust. Igneous, Metamorphic, and Sedimentary rocks compose the crust. Increasing as we progress further into the Earth, the temperatures can reach up to 871. 

The second layer of the geosphere is the mantle. The mantle (2,900 km thick)is about 84 percent of the Earth’s volume. Composed of silicate rocks which are rich magnesium and iron, the 2900 kilometer deep mantle simply gets hotter as we progress further downwards. The mantle’s temperatures are between 871 and 4,000. The upper mantle and the crust is called the asthenosphere and is also called the lithosphere.

The third layer of the geosphere is the outer core. The outer core (2,200 km thick) is about 15 percent of the Earth’s volume. The outer core is composed of liquid iron and nickel. The outer core’s temperature can reach up to 5,000. 

The fourth and final layer of the geosphere is the inner core. The inner core (1,220 km thick) and the outer core combined is about 15 percent of the Earth’s volume. The inner core is mostly comprised of iron. The inner core’s temperature can reach up to 6,000.

T he Geosphere is traditionally studied by Geologists and Geophysicists. These two disciplines include Stratigraphers (people who study the age and vertical arrangement of rocks), Petrologists (People who study igneous, metamorphic and sedimentary rock formation), Paleontologists, Volcanologists, and Seismologists. Geologists work both in terrestrial and marine environments. Surficial processes of the Geosphere are typically studied by Geomorphologists. Geomorphologists study rivers, arid landscapes, coastal environments and glacial landforms, to name a few. Other people who study the Geosphere include Environmental Geologists, who want to understand how the shape of slopes impact slope stability (Fig 20).

The land in north central Canada has been slowly lifting up after the melt of glaciers from the last ice age. Hydrosphere and Atmosphere: The erosion of rocks, a major part of the rock cycle and change in the geosphere over time, turns rock to sediment and then, sometimes, to sedimentary rock

What is the atmosphere?

Earth's atmosphere is 78% nitrogen, 21% oxygen, 0.9% argon, and 0.03% carbon dioxide with very small percentages of other elements. Our atmosphere also contains water vapor. In addition, Earth's atmosphere contains traces of dust particles, pollen, plant grains and other solid particles.

The early atmosphere was probably mostly carbon dioxide, with little or no oxygen. There were smaller proportions of water vapour, ammonia and methane. As the Earth cooled down, most of the water vapour condensed and formed the oceans.