Category Environtal Studies

HOW QUICKLY DOES LAND GET WORN AWAY?

Erosion is the geological process in which earthen materials are worn away and transported by natural forces such as wind or water. A similar process, weathering, breaks down or dissolves rock, but does not involve movement.

Erosion is the opposite of deposition, the geological process in which earthen materials are deposited, or built up, on a landform.

Most erosion is performed by liquid water, wind, or ice (usually in the form of a glacier). If the wind is dusty, or water or glacial ice is muddy, erosion is taking place. The brown color indicates that bits of rock and soil are suspended in the fluid (air or water) and being transported from one place to another. This transported material is called sediment.

Credit: National Geographic Society

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WHAT IS GROUNDWATER?

Rainwater seeps below the surface of the Earth and soaks the soil. When there is more water than the soil can absorb, it can seep even further down until it is surrounded by rocks, creating a kind of storage area, known as an aquifer. The water here is groundwater, and the upper level of water is called the water table.

Water that has travelled down from the soil surface and collected in the spaces between sediments and the cracks within rock is called groundwater. Groundwater fills in all the empty spaces underground, in what is called the saturated zone, until it reaches an impenetrable layer of rock. Groundwater is contained and flows through bodies of rock and sediment called aquifers. The amount of time that groundwater remains in aquifers is called its residence time, which can vary widely, from a few days or weeks to 10 thousand years or more.

The top of the saturated zone is called the water table, and sitting above the water table is the unsaturated zone, where the spaces in between rocks and sediments are filled with both water and air. Water found in this zone is called soil moisture, and is distinct from groundwater.

Existing groundwater can be discharged through springs, lakes, rivers, streams, or manmade wells. It is recharged by precipitation, snowmelt, or water seepage from other sources, including irrigation and leaks from water supply systems.

Credit: National Geographic Society

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WHAT IS SCREE?

Loose rocks of roughly the same size littered on steep mountain slopes.

Scree is a collection of broken rock fragments at the base of a cliff or other steep rocky mass that has accumulated through periodic rockfall. Landforms associated with these materials are often called talus deposits. Talus deposits typically have a concave upwards form, where the maximum inclination corresponds to the angle of repose of the mean debris particle size. The exact definition of scree in the primary literature is somewhat relaxed, and it often overlaps with both talus and colluvium.

The formation of scree and talus deposits is the result of physical and chemical weathering acting on a rock face, and erosive processes transporting the material downslope.

There are five main stages of scree slope evolution: (1) accumulation, (2) consolidation, (3) weathering, (4) encroaching vegetation, and finally, (5) slope degradation.

Credit: Wikipedia

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What are Hurricanes?

A hurricane is a giant, spiralling tropical storm in the Atlantic Ocean that can reach wind speeds of over 257 km per hour and unleash more than nine trillion litres of rain! It begins as thunderstorms that are set off by moist air rising over the warm ocean. If the water is warm enough, the thunderstorms join together, growing bigger as they begin to spiral across the ocean. As the hurricane grows, it spins faster and tighter around its centre, or ‘eye’, which remains a very calm area of low pressure. A hurricane can be as much as 800 km across and can take l8 hours to pass over. In the northern Indian Ocean hurricanes are known as cyclones and in the western Pacific Ocean, as typhoons.

Hurricanes are large, swirling storms. They produce winds of 119 kilometers per hour (74 mph) or higher. That’s faster than a cheetah, the fastest animal on land. Winds from a hurricane can damage buildings and trees.

Hurricanes form over warm ocean waters. Sometimes they strike land. When a hurricane reaches land, it pushes a wall of ocean water ashore. This wall of water is called a storm surge. Heavy rain and storm surge from a hurricane can cause flooding.

Once a hurricane forms, weather forecasters predict its path. They also predict how strong it will get. This information helps people get ready for the storm.

There are five types, or categories, of hurricanes. The scale of categories is called the Saffir-Simpson Hurricane Scale. The categories are based on wind speed.

  • Category 1: Winds 119-153 km/hr (74-95 mph) – faster than a cheetah
  • Category 2: Winds 154-177 km/hr (96-110 mph) – as fast or faster than a baseball pitcher’s fastball
  • Category 3: Winds 178-208 km/hr (111-129 mph) – similar, or close, to the serving speed of many professional tennis players
  • Category 4: Winds 209-251 km/hr (130-156 mph) – faster than the world’s fastest rollercoaster
  • Category 5: Winds more than 252 km/hr (157 mph) – similar, or close, to the speed of some high-speed trains

Credit: NASA

Picture credit: NASA

What is Meteorology?

No, it isn’t the study of meteors, although it does involve the study of other sorts of objects that fall from the sky. Meteorology is, by definition, the study of Earth’s atmosphere. The root of meteor is a variation on the Greek meteoron, which is a term dealing with any objects that originate in the sky.

Meteorology is an extremely interdisciplinary science, drawing on the laws of physics and chemistry (among others) to aid in our understanding of Earth’s atmosphere, its processes, and its structure. It is a study that dates to ancient times, when ancient civilizations made observations and kept records of weather conditions, both for agricultural purposes and out of a general curiosity about the world around them.

Over the centuries, the atmosphere has been studied for a variety of reasons, including agricultural knowledge, military defense and planning, and developing better warnings for severe weather systems like tornadoes and hurricanes. Technological advances, such as the development of scientific computing and an increase in the total number of meteorological observations being taken daily across the globe, have allowed for better forecasts (or at least the meteorological community likes to think they are better forecasts) and a much better overall understanding of our atmosphere.

Credit: Study.com

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What is Climatology?

Climatology is the study of the atmosphere and weather patterns over time. This field of science focuses on recording and analyzing weather patterns throughout the world and understanding the atmospheric conditions that cause them. It is sometimes confused with meteorology, which is the study of weather and weather forecasting. However, climatology is mainly focused on the natural and artificial forces that influence long-term weather patterns. Scientists who specialize in this field are called climatologists.

The first studies of climate can be traced back to ancient Greece, but climate science as it is now known did not emerge until the advent of the industrial age in the nineteenth century. The science of climatology grew as scientists became interested in understanding weather patterns. In recent times, climatologists have increasingly focused their research on the changes in Earth’s climate that have occurred since the industrial age. Earth has been growing warmer and warmer as human industry has expanded and released more carbon into the atmosphere. This effect, called global warming, is a particularly important object of study for climatologists. By studying global warming, climatologists can better understand and predict the long-term impact of human-caused climate change.

Credit: National Geographic Society

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