Weathering, the process by which rocks and minerals at Earth’s surface deteriorate due to external forces like water, ice, acids, salts, plants and animals breaking them down over time; air changes as well as changes in temperature also play a part.
Oxygen reacts with iron-containing minerals to soften them and make them easier to break down, creating soft soil layers over time and eventually smoothing rough rock surfaces into soil deposits.
Physical weathering refers to the process of breaking rocks down into smaller chunks or particles, whether through physical, chemical, or biological means.
Examples of weathering include the freeze-thaw process that occurs within rocks, plant roots growing into cracks in rocks, and the development of lichens; all of which contribute to breaking apart rocks through applying pressure.
Reason being, these formations provide more surface area for chemical weathering to occur more rapidly than if all rocks stayed together.
Acid rain is another excellent example of physical weathering, occurring when airborne chemicals convert to acids that fall onto rocks and minerals as raindrops. Acid rain has the ability to dissolve calcium found in limestone and marble structures causing their decay over time resulting in erosion over time and eventually destruction.
Chemical weathering refers to a process in which rocks and soil undergo changes in chemical composition as a result of exposure to moisture and warm temperatures, often with moisture speeding up this reaction.
Water can interact with iron in rocks to soften them and make them more likely to disintegrate – this process, known as oxidation, creates compounds such as rust. Water also dissolves minerals within rocks to produce new substances – this is called hydrolysis; an example would be when water drips onto granite to form clay minerals or seeps through cave floors to dissolve stalagmites and stalactites that have built up over time.
Plants and animals both play a part in mechanical and chemical weathering processes. Tree roots can enlarge cracks in rocks over time and cause them to crumble away, while animals who dig and tunnel can help break apart rocks too. Finally there is the abrasion caused by waves as well as erosion caused by wind.
Roots and other living organisms penetrating rocks can cause them to disintegrate through biological weathering or organic weathering, a phenomenon commonly referred to as biological weathering or organic weathering.
Root systems of trees, grasses, and plants can penetrate cracks in rock surfaces and break down some minerals present. Furthermore, their acids released can wear down rocks over time by changing their chemical makeup in what’s known as bioerosion.
Fungi are living organisms that can help make rock less hard by producing compounds to dissolve some mineral grains or by exchanging positive-charged cations for negatively charged hydrogen ions, making the rock less solid and making it more porous. Fungi can even make rocks weaker by creating pores in it that let more air through, weakening it further.
Burrowing creatures like shrews, moles and earthworms can help break up rocks by digging holes to expose their surfaces to the elements. People can hasten this natural weathering process by cultivating and ploughing soil before growing crops on it.
Imagine if weathering processes ceased entirely, leaving Earth covered with nothing but rock. Without vegetation or animals to support life on its surface, soil formation would never happen and life wouldn’t survive on our planet.
Human activities greatly facilitate and hasten weathering processes. For instance, burning fossil fuels releases nitrogen oxide and sulfur dioxide into the air that combines with sunlight and moisture in the form of acid rain; this causes decomposition of limestone and marble surfaces and may make gravestone inscriptions illegible. Furthermore, clearing trees for commercial and residential developments exposes rocks underfoot to increased sunlight exposure and chemical weathering processes that accelerate weathering processes.
Researchers have linked health measures like cortisol levels, sympathetic nerve activity, cytokine production, waist-to-hip ratio and glycated hemoglobin with social indicators such as socioeconomic status, occupation, pregnancy outcome and environmental risk. Their studies contributed to developing allostatic load – or the physiological cost of chronic stress. Chronic exposure to socioeconomic adversity, political marginalization or racism for instance can slowly wear down one’s health over time causing them to age prematurely or die sooner than planned.