Solid Ground: Geological Carbon Cycle Quiz

Chemical reactions happen faster when it is warm and wet. Plants also help by releasing acids from their roots and breaking rocks apart, exposing more surface area to the rain.

If Earth gets too hot, weathering increases, which pulls CO2 out of the air and cools the planet. If it gets too cold, weathering slows down, allowing volcanic CO2 to build up and warm the planet.

Diamonds represent carbon that has been subjected to extreme pressure and temperature deep within the geosphere, often brought to the surface by rare, deep-seated volcanic eruptions.

Usually, dead plants rot and return carbon to the air. But if they are buried quickly in swamps or seafloors, they enter the geological cycle and stay trapped for millions of years.

Volcanoes and weathering release carbon naturally. Human activity, like mining fossil fuels, takes carbon that was meant to stay in the geosphere for millions of years and releases it all at once.

The ocean receives the minerals dissolved from rocks on land. Marine organisms then use those minerals to build shells, which eventually sink and become the next generation of carbonate rocks.

These cliffs are made of billions of microscopic coccolithophore shells that were sequestered on the seafloor during the Cretaceous period and later pushed up by tectonic forces.

This deep cycle connects the surface of the Earth to the mantle, ensuring that carbon is constantly recycled rather than being permanently lost to the interior of the planet.

Rainwater reacts with CO2 to form weak carbonic acid. This acid dissolves silicate rocks on land, washing calcium and bicarbonate ions into the ocean, where they eventually form limestone.

Unlike the biological cycle, the geological cycle takes millions of years. It involves the slow movement of carbon through rock formation, plate tectonics, and volcanic eruptions.

As oceanic plates sink beneath continental plates, they carry carbonate rocks into the hot mantle. This carbon is eventually melted and returned to the atmosphere through volcanoes.

Most of Earths carbon is locked away in rocks like limestone or buried as ancient organic matter. Only a tiny fraction of the planets total carbon is actually in the atmosphere at any given time.

Volcanoes are the primary natural exhaust pipes of the geological cycle, returning carbon that was trapped underground for millions of years back to the air as CO2 gas.

When new mountains form, they provide more fresh rock for chemical weathering. This increases the rate at which CO2 is pulled out of the atmosphere, which can lead to a long-term cooling effect on the climate.

Over millions of years, the marine snow of calcium carbonate shells is compressed under the weight of the ocean, turning soft ooze into solid limestone rock.