Factors that Influence Climate - Climate and Weather
Weather reflects short-term conditions of the atmosphere while climate is the average daily weather for an extended period of time at a certain location. Mar 23, Though climate and weather are closely related, they aren't the same thing. Looking at Climate Normals can help us describe whether the. Climate and weather - humidity, air temperature and pressure, wind speed and winds known as jet streams help move weather systems around the world.
CLIMATE & WEATHER
Chemical weathering typically increases as temperatures rise and rain falls, which means rocks in hot and wet climates experience faster rates of chemical weathering than do rocks in cold, dry climates. Sciencing Video Vault Physical weathering occurs more often in cold climates, because the different minerals within rocks expand and contract at different rates when they are heated and cooled.
Repeated heating and cooling cycles eventually cause rocks to fracture. Desert and mountain climates experience a wide range of temperatures from low to high during a day and night, which accounts for the breakdown of rocks known as physical weathering.
Biological weathering occurs when living organisms break up rocks. Tree roots, for example, can fracture rocks in the same way they buckle pavement. Warm, humid climates are most favorable to life. Contrast the rich diversity of life in a rainforest, for example, with the scarcity of life in the dry Sahara or the frigid Antarctic.
Consequently, rates of biological weathering are most rapid in warm humid climates like those in tropical regions. Some types of rocks weather more rapidly in humid climates, while dry climates make other rocks more susceptible to attack.
Climate Change Indicators: Weather and Climate
Erosion relies on transporting agents such as wind, rivers, ice, snow and downward movement of materials to carry weathered products away from the source area. As weathered products are carried away, fresh rocks are exposed to further weathering.
Over time, that mountain or hill is gradually worn down. There are two types of weathering: Oxygen oxidizes minerals to alteration products whereas water can convert minerals to clays or dissolve minerals completely. Different minerals weather at different rates. Mafic silicates like olivine and pyroxene tend to weather much faster than felsic minerals like quartz and feldspar. Different minerals show different degrees of solubility in water in that some minerals dissolve much more readily than others.
Water dissolves calcite more readily than it does feldspar, so calcite is considered to be more soluble than feldspar.
How Does Climate Affect the Rate of Weathering? | Sciencing
Massive rocks like granite generally to not contain planes of weakness whereas layered sedimentary rocks have bedding planes that can be easily pulled apart and infiltrated by water. Weathering therefore occurs more slowly in granite than in layered sedimentary rocks. Rainfall and temperature can affect the rate in which rocks weather.
High temperatures and greater rainfall increase the rate of chemical weathering. Rocks in tropical regions exposed to abundant rainfall and hot temperatures weather much faster than similar rocks residing in cold, dry regions. Soils affect the rate in which a rock weathers. Soils retain rainwater so that rocks covered by soil are subjected to chemical reactions with water much longer than rocks not covered by soil.
Soils are also host to a variety of vegetation, bacteria and organisms that produce an acidic environment which also promotes chemical weathering.
Minerals in a rock buried in soil will therefore break down more rapidly than minerals in a rock that is exposed to air. Length of Exposure 1.
The longer a rock is exposed to the agents of weathering, the greater the degree of alteration, dissolution and physical breakup. Lava flows that are quickly buried by subsequent lava flows are less likely to be weathered than a flow which remains exposed to the elements for long periods of time.
Chemical Weathering Chemical weathering is a process where minerals in a rock may be converted into clays, oxidized or simply dissolved. Silicates comprise almost all minerals in igneous rocks and are also important components in metamorphic rocks.
Not all silicates, however, survive weathering processes to become incorporated into sedimentary rocks. Chemical weathering may involve the disintegration of a rock into rock fragments due to conversion of silicates into clays. For example, interlocking silicate grains in fresh granite gradually decay along crystal boundaries due to conversion to clays. Eventually cracks open around the boundaries, the rock weakens and easily disintegrates. The process by which silicates decay is analogous to the brewing of coffee.
Water dissolves some of the solid, leaving behind an altered material and producing a solution containing substances drawn from the original solid coffee grounds. The conversion of silicates to clays is enhanced when the water is slightly acidic. The acid rainwater than reacts with minerals on the exposed rock face. Reaction of silicates with carbonic acid and water produces clays and also releases Si and certain cations into water as dissolved constituents: The dissolved cations are carried away by rain and river waters and ultimately transported to the oceans.
In tropical regions, clays can further react with water to form Bauxite Al-hydroxidean ore which is a major source of Al. As weathering breaks down a rock into smaller particles, the surface area increases so that the process of chemical weathering is accelerated. Dissolving of Minerals 1. Slightly acidic rainwater can also react with non-silicates in a rock or soil.Basics of Geography: Climate
For instance, carbonic acid can dissolve carbonates such as calcite so that all constinuents go into solution. Oxidation involves the combining of certain metals Fe in particular with oxygen in the process of stealing electrons. During oxidation, metals like Fe lose one or more electrons to oxygen. Iron can also dissolve in water as cations. Iron oxide minerals are widespread and have the characteristic red and brown colors seen in desert sediments and red soils in humid regions.
Iron oxides, Al-hydroxides, clay minerals and quartz are the most stable weathered products whereas highly soluble minerals like halite are the least stable. Silicates fall within the middle range. The most common silicates in clastic sedimentary rocks are quartz, K- Na-feldspars and micas. Amphiboles, pyroxene, olivine and Ca-feldspars are almost never found in sedimentary rocks.