In strictest geological terms, a volcano is a vent from which magma and other substances erupt to the surface or it is a landform composed of the volcanic debris and solidified lava found near the opening of a vent. These landforms have been in existence since the beginning of volcanic activity. One such volcano would be Mauna Loa. It is classified as a shield volcano; a landform that is usually huge with gentle slopes and many layers of what was once fluid lava. The opposite would be Mount Fuji. This volcano is a classic stratovolcano. It has steep slopes built of layer upon layer of lava and ash. A third type is a submarine volcanic landform found upon the Icelandic seafloor.
Geologists have discovered that the interior heat from large planetary bodies such as Earth has difficulty escaping by such common processes as radiation or conduction and instead uses a method of convection, a partial melting of the Earth’s crust and mantle whereby magma rises to he surface.
Volcanoes give evidence of the directions and rates of motion of the Earth’s tectonic plates. Their study comes under the banners of geophysicists, geochemists, geologists, biologists and meteorologists. Their disciplines cover everything from the roots of volcanoes, signs of future eruptions, the plants and animals who find volcanoes a suitable habitat, and the effects of volcanic dust and gases on the atmosphere, the weather and climate.
Volcanoes enrich the soil making it fertile. One will find valuable mineral deposits and geothermal energy. Over time they even benefit by recycling the planet’s hydrosphere and atmosphere. They create beautiful scenery that mystifies the onlooker. But as we all know too well volcanoes are associated with a long list of destructive hazards. They produce legendary lava flows, explosions, toxic gas clouds, dangerous ash falls, pyroclastic flows, avalanches, tsunamis and mudflows. Secondary is the property damage and crop loss.
If you hunt for rocks near the surface of a vent you will find four major types or what they call clans. There are basalt, andesite, dacite and rhyloite. The range in silica content from 50% to 75%. The higher the silica content the more viscous the rock.
. When the archaeologist finishes his/her studies it s the geologist who continues our journey into the remotest areas of earth’s antiquities. Rocks remember.
Rocks remember. When the archaeologist finishes his/her study it s the geologist who continues our journey into the remotest areas of Earth’s antiquities.
Covering the Earth are seven belts of atmospheric pressure. The lowest can be found at the equator. They increase as they move towards the poles. The major wind systems lie between these zones of low and high pressure and are referred to as; the northeast and southeast trade winds, the westerlies which include the roaring forties and furious fifties, the polar easterlies and finally the monsoons.
As air rises, the pressure lowers and the air around it moves in causing wind. The greater the degree of pressure over a given distance the faster the wind. This action is called pressure gradient force. Most wind moves across the ground. It is unusual for it to move up and down except where there are thunderstorm downdrafts. One other force that must be considered is known in physics as the Coriolis effect. When a mass is moving in a rotating system there is a force acting perpendicular to the direction of motion and to the axis of rotation. On Earth moving objects are subject to deflection to the right if in the northern hemisphere and to the left if in the southern hemisphere. This effect becomes important when discussing the formation of cyclonic weather systems.
Seasonal winds include all movements of air that are repetitive and predictable forming what become known as weather patterns. They are found in various geographic regions around the world. The most common are the monsoon winds. The monsoon is a low latitude wind which changes direction between summer and winter. During winter it blows from the land and is composed of cool dry air and from the water to the land in summer when the air is moist and warm. These conditions cause drastic changes in the amount of precipitation and in the temperature patterns of the area where the monsoon occurs. Southern Asia experiences the most pronounced monsoon system however one can find this system happening in West Africa, Australia and the Pacific Ocean. There is even a small system called the North American monsoon, the Mexican monsoon or Arizona monsoon. The monsoon impacts the agricultural economies of the area. It can cause flooding, severe winds and the loss off many many lives.
Short bursts of wind are called gusts. Stronger winds lasting about a minute are known as squalls. Longer winds of increasing strength are termed breezes, gales, storms and hurricanes.
From times of myth, through times of history the wind has influenced thinkers in the fields of warfare, mechanics, transportation, power generation and recreation. They have shaped landscapes from deserts to fertile soil. They have impacted wildfires, dispersed seeds encouraging the survival of plant species, had negative consequences for farm animals, disturbed hunting grounds, and thwarted defensive strategies.
In conclusion let it be said of the wind:
When you can’t change its direction, adjust your sails.
Air pollution is not just a local concern but a growing regional, national and international concern. It involves identifying levels of dangerous pollutants and where they originate. Emissions need to be controlled. Effective legislation must be drafted, debated and passed . With the creation of such agencies as the E.P.A. which was responsible for implementing the Clean Air Act Amendments of 1970 improvements abounded. Air Quality Standards were established and strictly followed.
Criteria for six pollutants were isolated and standards set. These were:. particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides, lead and ozone. In setting the standards such matters as health considerations, environmental conditions, vegetation, esthetics, houses and monuments were discussed in depth. When standards were not met the section under scrutiny was designated a nonattainment area. Air quality is reviewed every five years. Should it be more often some ask.
A form of air pollution not mentioned yet is acid rain; a term used to cover acidic precipitation of all kinds including rain, snow, fog and dust particles. When pollutants get into the air, in particular sulfur dioxide and nitrogen oxides, they produce acid rain which in turn has serious consequences for the biosystems on land and in water. Some subsequent problems are damaged leaves, compromised photosynthesis, waters so acidic they can no longer support fish or smaller organisms and marred recreational areas.
Air pollution is not going away any time soon and as of today there’s no Planet B.
Springs are more and more often being threatened with pollution. They are daily contaminated by industrial and muncipal discharge, runoff, spills and airborne pollutants. In time, the ecosystem will be dangerously unbalanced. Other culprits that threaten are agricultural. The toxic synthetic chemicals being used cannot be broken down by natural processes.
Governments announce many a Protection Act; establish Clean Funds to preserve the integrity of water science. They frequently invest in infrastructure and support research yet amongst the general population maintaining a vigilant conscience concerned with a clean safe water supply is difficult.
Most of us remain smilingly ignorant of the problem until a water crisis dominates in the news. One cannot stress enough how important it is for all of us to acknowledge the part we have to play in maintaining a clean water supply, not just for ourselves and our family but for everyone.
What can we do? Well, we can reduce our use of herbicides, pesticides and fertilizers. We can reduce our use of bleach and detergents. We can also refuse to dispose by flushing down the drain such things as pills, drugs or medications. There are more ways to help and I will leave it up to you the reader to find them.