In earth science, erosion is the action of surface processes that remove soil, rock, or dissolved material from one location on the Earths crust, transport it away to another location. Eroded sediment or solutes may be transported just a few millimetres, the rates at which such processes act control how fast a surface is eroded. Feedbacks are possible between rates of erosion and the amount of eroded material that is carried by, for example. Processes of erosion that produce sediment or solutes from a place contrast with those of deposition, while erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. At well-known agriculture sites such as the Appalachian Mountains, intensive farming practices have caused erosion up to 100x the speed of the rate of erosion in the region. Excessive erosion causes both on-site and off-site problems, on-site impacts include decreases in agricultural productivity and ecological collapse, both because of loss of the nutrient-rich upper soil layers.
In some cases, the end result is desertification. Off-site effects include sedimentation of waterways and eutrophication of bodies, as well as sediment-related damage to roads. Intensive agriculture, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils. Rainfall, and the surface runoff which may result from rainfall, produces four types of soil erosion, splash erosion, sheet erosion, rill erosion. Splash erosion is generally seen as the first and least severe stage in the erosion process. In splash erosion, the impact of a falling raindrop creates a crater in the soil. The distance these soil particles travel can be as much as 0.6 m vertically and 1.5 m horizontally on level ground. If the soil is saturated, or if the rate is greater than the rate at which water can infiltrate into the soil.
If the runoff has sufficient flow energy, it will transport loosened soil particles down the slope, sheet erosion is the transport of loosened soil particles by overland flow. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes, where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are typically of the order of a few centimetres or less and this means that rills exhibit hydraulic physics very different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when water accumulates and rapidly flows in narrow channels during or immediately after heavy rains or melting snow
Straw is an agricultural by-product, the dry stalks of cereal plants, after the grain and chaff have been removed. Straw makes up half of the yield of cereal crops such as barley, rice, rye. It has many uses, including fuel, livestock bedding and fodder and it is usually gathered and stored in a straw bale, which is a bundle of straw tightly bound with twine or wire. Bales may be square, rectangular, or round, depending on the type of baler used. Current and historic uses of straw include, Animal feed Straw may be fed as part of the component of the diet to cattle or horses that are on a near maintenance level of energy requirement. It has a low energy and nutrient content. The heat generated when microorganisms in a herbivores gut digest straw can be useful in maintaining body temperature in cold climates, due to the risk of impaction and its poor nutrient profile, it should always be restricted to part of the diet. It may be fed as it is, or chopped into short lengths, basketry Bee skeps and linen baskets are made from coiled and bound together continuous lengths of straw.
The technique is known as lip work, humans or livestock The straw-filled mattress, known as a palliasse, is still used in many parts of the world. It is commonly used as bedding for ruminants and horses and it may be used as bedding and food for small animals, but this often leads to injuries to mouth and eyes as straw is quite sharp. Biofuels The use of straw as an energy source is increasing rapidly, especially for biobutanol. Straw or hay briquettes are a substitute to coal. Biogas Straw, processed first as briquettes, has been fed into a plant in Aarhus University, Denmark. Biomass The use of straw in large-scale biomass power plants is becoming mainstream in the EU, the straw is either used directly in the form of bales, or densified into pellets which allows for the feedstock to be transported over longer distances. Finally, torrefaction of straw with pelletisation is gaining attention, because it increases the density of the resource. This processing step makes storage easier, because torrefied straw pellets are hydrophobic.
Torrefied straw in the form of pellets can be directly co-fired with coal or natural gas at high rates and make use of the processing infrastructures at existing coal. Because the torrefied straw pellets have superior structural and combustion properties to coal, they can replace all coal, first generation pellets are limited to a co-firing rate of 15% in modern IGCC plants
Schleswig-Holstein is the northernmost of the 16 states of Germany, comprising most of the historical duchy of Holstein and the southern part of the former Duchy of Schleswig. Its capital city is Kiel, other cities are Lübeck. Also known in more dated English as Sleswick-Holsatia, the Danish name is Slesvig-Holsten, the Low German name is Sleswig-Holsteen, the name can refer to a larger region, containing both present-day Schleswig-Holstein and the former South Jutland County in Denmark. The term Holstein derives from Old Saxon Holseta Land, originally, it referred to the central of the three Saxon tribes north of the River Elbe, Tedmarsgoi and Sturmarii. The area of the tribe of the Holsts was between the Stör River and Hamburg, and after Christianization, their church was in Schenefeld. Saxon Holstein became a part of the Holy Roman Empire after Charlemagnes Saxon campaigns in the eighth century. Since 811, the frontier of Holstein was marked by the River Eider. The term Schleswig comes from the city of Schleswig, around 1100, the Duke of Saxony gave Holstein, as it was his own country, to Count Adolf I of Schauenburg.
Schleswig and Holstein have at different times belonged in part or completely to either Denmark or Germany, the exception is that Schleswig had never been part of Germany until the Second Schleswig War in 1864. For many centuries, the King of Denmark was both a Danish Duke of Schleswig and a German Duke of Holstein, Schleswig was either integrated into Denmark or was a Danish fief, and Holstein was a German fief and once a sovereign state long ago. Both were for centuries ruled by the kings of Denmark. In the church, following the reformation, German was used in the part of Schleswig. This would prove decisive for shaping national sentiments in the population, the administration of both duchies was conducted in German, despite the fact that they were governed from Copenhagen. The German national awakening that followed the Napoleonic Wars gave rise to a popular movement in Holstein. This development was paralleled by an equally strong Danish national awakening in Denmark and this movement called for the complete reintegration of Schleswig into the Kingdom of Denmark and demanded an end to discrimination against Danes in Schleswig.
The ensuing conflict is called the Schleswig-Holstein Question. e. Not only in the Kingdom of Denmark, but to Danes living in Schleswig, they demanded protection for the Danish language in Schleswig. A liberal constitution for Holstein was not seriously considered in Copenhagen and these demands were rejected by the Danish government in 1848, and the Germans of Holstein and southern Schleswig rebelled
Plant pathology is the scientific study of diseases in plants caused by pathogens and environmental conditions. Organisms that cause infectious disease include fungi, bacteria, viroids, virus-like organisms, protozoa, not included are ectoparasites like insects, vertebrate, or other pests that affect plant health by consumption of plant tissues. Control of plant diseases is crucial to the production of food. Plants in both natural and cultivated populations carry inherent disease resistance, but there are examples of devastating plant disease impacts. However, disease control is reasonably successful for most crops, plant diseases cause major economic losses for farmers worldwide. The Food and Agriculture Organization estimates indeed that pests and diseases are responsible for about 25% of crop loss, most phytopathogenic fungi belong to the Ascomycetes and the Basidiomycetes. The fungi reproduce sexually and asexually via the production of spores and other structures. Spores may be spread long distances by air or water, or they may be soilborne, Many soil inhabiting fungi are capable of living saprotrophically, carrying out the part of their life cycle in the soil.
These are known as facultative saprotrophs, fungal diseases may be controlled through the use of fungicides and other agriculture practices. However, new races of fungi often evolve that are resistant to various fungicides, biotrophic fungal pathogens colonize living plant tissue and obtain nutrients from living host cells. Necrotrophic fungal pathogens infect and kill host tissue and extract nutrients from the dead host cells, see the powdery mildew and rice blast images, below. Significant fungal plant pathogens include, Fusarium spp, magnaporthe grisea Sclerotinia sclerotiorum Ustilago spp. The oomycetes are not true fungi but are fungus-like organisms and they include some of the most destructive plant pathogens including the genus Phytophthora, which includes the causal agents of potato late blight and sudden oak death. Particular species of oomycetes are responsible for root rot, despite not being closely related to the fungi, the oomycetes have developed very similar infection strategies.
Oomycetes are capable of using effector proteins to turn off a plants defenses in its infection process, plant pathologists commonly group them with fungal pathogens. Significant oomycete plant pathogens Pythium spp and these are caused by species of Plasmodiophora and Spongospora, respectively. Most bacteria that are associated with plants are actually saprotrophic and do no harm to the plant itself, however, a small number, around 100 known species, are able to cause disease. Bacterial diseases are more prevalent in subtropical and tropical regions of the world
A drought is a period of below-average precipitation in a given region, resulting in prolonged shortages in its water supply, whether atmospheric, surface water or ground water. A drought can last for months or years, or may be declared after as few as 15 days and it can have a substantial impact on the ecosystem and agriculture of the affected region and harm to the local economy. Annual dry seasons in the tropics significantly increase the chances of a drought developing, periods of heat can significantly worsen drought conditions by hastening evaporation of water vapour. Many plant species, such as those in the family Cactaceae, have drought tolerance adaptations like reduced leaf area, some others survive dry periods as buried seeds. Semi-permanent drought produces arid biomes such as deserts and grasslands, prolonged droughts have caused mass migrations and humanitarian crises. Most arid ecosystems have inherently low productivity, the most prolonged drought ever in the world in recorded history occurred in the Atacama Desert in Chile.
Mechanisms of producing precipitation include convective and orographic rainfall, precipitation can be divided into three categories, based on whether it falls as liquid water, liquid water that freezes on contact with the surface, or ice. Drought are mainly course by in low rain areas, if these factors do not support precipitation volumes sufficient to reach the surface over a sufficient time, the result is a drought. Once a region is within drought, feedback mechanisms such as local arid air, hot conditions which can promote warm core ridging, within the tropics, distinct and dry seasons emerge due to the movement of the Intertropical Convergence Zone or Monsoon trough. The dry season greatly increases drought occurrence, and is characterized by its low humidity, with watering holes, because of the lack of these watering holes, many grazing animals are forced to migrate due to the lack of water and feed to more fertile spots. Examples of such animals are zebras and wildebeest, because of the lack of water in the plants, bushfires are common.
Since water vapor becomes more energetic with increasing temperature, more water vapor is required to increase relative humidity values to 100% at higher temperatures, periods of warmth quicken the pace of fruit and vegetable production, increase evaporation and transpiration from plants, and worsen drought conditions. Drier and hotter weather occurs in parts of the Amazon River Basin, winters during the El Niño are warmer and drier than average conditions in the Northwest, northern Midwest, and northern Mideast United States, so those regions experience reduced snowfalls. Conditions are drier than normal from December to February in south-central Africa, mainly in Zambia, Zimbabwe and Botswana. Direct effects of El Niño resulting in drier conditions occur in parts of Southeast Asia and Northern Australia, increasing bush fires, worsening haze, drier-than-normal conditions are in general observed in Queensland, inland Victoria, inland New South Wales, and eastern Tasmania from June to August.
As warm water spreads from the west Pacific and the Indian Ocean to the east Pacific, it causes extensive drought in the western Pacific. Singapore experienced the driest February in 2014 since records began in 1869, with only 6.3 mm of rain falling in the month, the years 1968 and 2005 had the next driest Februaries, when 8.4 mm of rain fell. Human activity can directly trigger exacerbating factors such as farming, excessive irrigation, deforestation
Volgograd Oblast is a federal subject of Russia. The population was 2,610,161 in the 2010 Census, borders length,2,221.9 kilometers Volgograd Oblast borders with Saratov, Rostov and Voronezh Oblasts, as well as with the Republic of Kalmykia of Russia and with Kazakhstan. Volgograd has more than 200 rivers and streams, the major ones include, The Volga River The Don River The Medveditsa River The Khopyor River Stalingrad Oblast was established on December 5,1936 on the territory of former Stalingrad Krai. The oblast was given its present name on November 10,1961, the Charter of Volgograd Oblast provides the fundamental law of the region. The Legislative Assembly of Volgograd Oblast is the provinces standing legislative body, the Legislative Assembly exercises its authority by passing laws and other legal acts and by supervising the implementation and observance of the laws and other legal acts passed by it. It is estimated that the proportion of ethnicities in this group is the same as that of the declared group, according to a 2012 official survey 54.
In addition, 18% of the population declares to be spiritual but not religious, 12% is atheist, and 6. 5% follows other religions or did not give an answer to the question. Governor of Volgograd Oblast is Anatoliy Brovko Both the flag and the coat of arms of Volgograd Oblast include an image of The Motherland Calls, primary branches of economics are agriculture, food production, heavy industry and petroleum refining. Volga Hydroelectric Station operates on the Volga River, list of Chairmen of the Volgograd Oblast Duma Volgograd floating landing Волгоградская областная Дума. Закона №90-ОД от10 июля2015 г, «О внесении изменений в статью2 Устава Волгоградской области от24 февраля2012 г. Вступил в силу по истечении десяти дней после дня официального опубликования, Опубликован, Волгоградская правда, №35,29 февраля2012 г. Исполнительный комитет Волгоградского областного Совета депутатов трудящихся, Административно-территориальное деление на1 июля1968 года. Official website of Volgograd Oblast Central Eurasian Information Resource, Images of Volgograd Oblast - University of Washington Digital Collections
Germany, officially the Federal Republic of Germany, is a federal parliamentary republic in central-western Europe. It includes 16 constituent states, covers an area of 357,021 square kilometres, with about 82 million inhabitants, Germany is the most populous member state of the European Union. After the United States, it is the second most popular destination in the world. Germanys capital and largest metropolis is Berlin, while its largest conurbation is the Ruhr, other major cities include Hamburg, Cologne, Stuttgart, Düsseldorf and Leipzig. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity, a region named Germania was documented before 100 AD. During the Migration Period the Germanic tribes expanded southward, beginning in the 10th century, German territories formed a central part of the Holy Roman Empire. During the 16th century, northern German regions became the centre of the Protestant Reformation, in 1871, Germany became a nation state when most of the German states unified into the Prussian-dominated German Empire.
After World War I and the German Revolution of 1918–1919, the Empire was replaced by the parliamentary Weimar Republic, the establishment of the national socialist dictatorship in 1933 led to World War II and the Holocaust. After a period of Allied occupation, two German states were founded, the Federal Republic of Germany and the German Democratic Republic, in 1990, the country was reunified. In the 21st century, Germany is a power and has the worlds fourth-largest economy by nominal GDP. As a global leader in industrial and technological sectors, it is both the worlds third-largest exporter and importer of goods. Germany is a country with a very high standard of living sustained by a skilled. It upholds a social security and universal health system, environmental protection. Germany was a member of the European Economic Community in 1957. It is part of the Schengen Area, and became a co-founder of the Eurozone in 1999, Germany is a member of the United Nations, NATO, the G8, the G20, and the OECD.
The national military expenditure is the 9th highest in the world, the English word Germany derives from the Latin Germania, which came into use after Julius Caesar adopted it for the peoples east of the Rhine. This in turn descends from Proto-Germanic *þiudiskaz popular, derived from *þeudō, descended from Proto-Indo-European *tewtéh₂- people, the discovery of the Mauer 1 mandible shows that ancient humans were present in Germany at least 600,000 years ago. The oldest complete hunting weapons found anywhere in the world were discovered in a mine in Schöningen where three 380, 000-year-old wooden javelins were unearthed
A conveyor belt is the carrying medium of a belt conveyor system. A belt conveyor system is one of many types of conveyor systems, a belt conveyor system consists of two or more pulleys, with an endless loop of carrying medium—the conveyor belt—that rotates about them. One or both of the pulleys are powered, moving the belt and the material on the belt forward, the powered pulley is called the drive pulley while the unpowered pulley is called the idler pulley. Today there are different types of belts that have been created for conveying different kinds of material available in PVC. The belt consists of one or more layers of material, many belts in general material handling have two layers. An under layer of material to provide strength and shape called a carcass. The carcass is often a woven fabric having a warp & weft, the most common carcass materials are polyester and cotton. The cover is often various rubber or plastic compounds specified by use of the belt, covers can be made from more exotic materials for unusual applications such as silicone for heat or gum rubber when traction is essential. A conveyor belt can be a slide and be controlled by the force of gravity, material flowing over the belt may be weighed in transit using a beltweigher.
Belts with regularly spaced partitions, known as elevator belts, are used for transporting loose materials up steep inclines, Belt Conveyors are used in self-unloading bulk freighters and in live bottom trucks. Belt conveyor technology is used in conveyor transport such as moving sidewalks or escalators. Stores often have conveyor belts at the counter to move shopping items. Ski areas use conveyor belts to transport skiers up the hill, some of the major global conveyor belt manufacturers and service providers are Fenner plc, Kale Conveyor, Terra Nova Technologies, ThyssenKrupp, HESE Maschinenfabrik GmbH and Tenova Takraf. Conveyors are durable and reliable components used in automated distribution and warehousing, in combination with computer controlled pallet handling equipment this allows for more efficient retail and manufacturing distribution. Rubber conveyor belts are used to convey items with irregular bottom surfaces. Belt conveyors are generally similar in construction consisting of a metal frame with rollers at either end of a flat metal bed.
The belt is looped around each of the rollers and when one of the rollers is powered the belting slides across the metal frame bed. In heavy use applications the beds which the belting is pulled over are replaced with rollers, the rollers allow weight to be conveyed as they reduce the amount of friction generated from the heavier loading on the belting
A seedling is a young plant sporophyte developing out of a plant embryo from a seed. Seedling development starts with germination of the seed, a typical young seedling consists of three main parts, the radicle, the hypocotyl, and the cotyledons. The two classes of flowering plants are distinguished by their numbers of seed leaves, monocotyledons have one blade-shaped cotyledon, for example, pine seedlings have up to eight cotyledons. The seedlings of some flowering plants have no cotyledons at all and these are said to be acotyledons. The plumule is the part of an embryo that develops into the shoot bearing the first true leaves of a plant. In most seeds, for example the sunflower, the plumule is a conical structure without any leaf structure. Growth of the plumule does not occur until the cotyledons have grown above ground, however, in seeds such as the broad bean, a leaf structure is visible on the plumule in the seed. These seeds develop by the growing up through the soil with the cotyledons remaining below the surface.
This is known as hypogeal germination, dicot seedlings grown in the light develop short hypocotyls and open cotyledons exposing the epicotyl. This is referred to as photomorphogenesis, in contrast, seedlings grown in the dark develop long hypocotyls and their cotyledons remain closed around the epicotyl in an apical hook. This is referred to as skotomorphogenesis or etiolation, etiolated seedlings are yellowish in color as chlorophyll synthesis and chloroplast development depend on light. They will open their cotyledons and turn green when treated with light, in a natural situation, seedling development starts with skotomorphogenesis while the seedling is growing through the soil and attempting to reach the light as fast as possible. During this phase, the cotyledons are tightly closed and form the hook to protect the shoot apical meristem from damage while pushing through the soil. In many plants, the seed coat still covers the cotyledons for extra protection, upon breaking the surface and reaching the light, the seedlings developmental program is switched to photomorphogenesis.
The cotyledons open upon contact with light and become green, forming the first photosynthetic organs of the young plant, until this stage, the seedling lives off the energy reserves stored in the seed. The opening of the cotyledons exposes the shoot apical meristem and the plumule consisting of the first true leaves of the young plant, the seedlings sense light through the light receptors phytochrome and cryptochrome. Once the seedling starts to photosynthesize, it is no longer dependent on the energy reserves. The apical meristems start growing and give rise to the root and shoot, the first true leaves expand and can often be distinguished from the round cotyledons through their species-dependent distinct shapes
A season is a division of the year marked by changes in weather and hours of daylight. Seasons result from the orbit of the Earth around the Sun. During May and July, the northern hemisphere is exposed to direct sunlight because the hemisphere faces the sun. The same is true of the hemisphere in November, December. It is the tilt of the Earth that causes the Sun to be higher in the sky during the months which increases the solar flux. However, due to lag, June and August are the hottest months in the northern hemisphere and December, January. In temperate and subpolar regions, four calendar-based seasons are recognized, summer, autumn or fall. Ecologists often use a model for temperate climate regions, vernal, serotinal, autumnal. Many tropical regions have two seasons, the rainy, wet, or monsoon season and the dry season, some have a third cool, mild, or harmattan season. Seasons often held special significance for agrarian societies, whose lives revolved around planting and harvest times, in some parts of the world, some other seasons capture the timing of important ecological events such as hurricane season, tornado season, and wildfire season.
The most historically important of these are the three seasons—flood and low water—which were previously defined by the annual flooding of the Nile in Egypt. The seasons result from the Earths axis of rotation being tilted with respect to its orbital plane by an angle of approximately 23.5 degrees, regardless of the time of year, the northern and southern hemispheres always experience opposite seasons. This is because during summer or winter, one part of the planet is directly exposed to the rays of the Sun than the other. For approximately half of the year, the northern hemisphere tips toward the Sun, for the other half of the year, the same happens, but in the southern hemisphere instead of the northern, with the maximum around December 21. The two instants when the Sun is directly overhead at the Equator are the equinoxes. Also at that moment, both the North Pole and the South Pole of the Earth are just on the terminator, and hence day and night are equally divided between the northern and southern hemispheres.
Around the March equinox, the northern hemisphere will be experiencing spring as the hours of daylight increase, the effect of axial tilt is observable as the change in day length and altitude of the Sun at noon during a year. Between this effect and the daylight hours, the axial tilt of the Earth accounts for most of the seasonal variation in climate in both hemispheres
Autumn, known as fall in North American English, is one of the four temperate seasons. One of its features is the shedding of leaves from deciduous trees. Some cultures regard the autumnal equinox as mid-autumn, while others with a longer temperature lag treat it as the start of autumn. Meteorologists use a definition based on months, with autumn being September and November in the northern hemisphere, in North America, autumn is usually considered to start with the September equinox and end with the winter solstice. As daytime and nighttime temperatures decrease, trees shed their leaves, in traditional East Asian solar term, autumn starts on or around 8 August and ends on or about 7 November. In Ireland, the autumn months according to the meteorological service. In Australia and New Zealand, autumn officially begins on 1 March, the word autumn comes from the ancient Etruscan root autu- and has within it connotations of the passing of the year. It was borrowed by the neighbouring Romans, and became the Latin word autumnus, after the Roman era, the word continued to be used as the Old French word autompne or autumpne in Middle English, and was normalized to the original Latin.
In the Medieval period, there are examples of its use as early as the 12th century. Before the 16th century, harvest was the usually used to refer to the season. The alternative word fall for the season traces its origins to old Germanic languages, the exact derivation is unclear, with the Old English fiæll or feallan and the Old Norse fall all being possible candidates. However, these all have the meaning to fall from a height and are clearly derived either from a common root or from each other. The term came to denote the season in 16th century England, during the 17th century, English emigration to the British colonies in North America was at its peak, and the new settlers took the English language with them. While the term gradually became obsolete in Britain, it became the more common term in North America. The name backend, a common name for the season in Northern England, has today been largely replaced by the name autumn. Association with the transition from warm to cold weather, and its status as the season of the primary harvest, has dominated its themes.
In Western cultures, personifications of autumn are usually pretty, well-fed females adorned with fruits, many cultures feature autumnal harvest festivals, often the most important on their calendars. There are the many North American Indian festivals tied to harvest of ripe foods gathered in the wild, the Chinese Mid-Autumn or Moon festival, and many others
Types of volcanic eruptions
Several types of volcanic eruptions—during which lava and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior has been observed, some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series. There are three different types of eruptions, the most well-observed are magmatic eruptions, which involve the decompression of gas within magma that propels it forward. Phreatomagmatic eruptions are another type of eruption, driven by the compression of gas within magma. Within these wide-defining eruptive types are several subtypes, the weakest are Hawaiian and submarine, followed by Vulcanian and Surtseyan. The stronger eruptive types are Pelean eruptions, followed by Plinian eruptions and phreatic eruptions are defined by their eruptive mechanism, and vary in strength.
An important measure of strength is Volcanic Explosivity Index, an order of magnitude scale ranging from 0 to 8 that often correlates to eruptive types. Explosive eruptions are characterized by gas-driven explosions that propels magma and tephra, effusive eruptions, are characterized by the outpouring of lava without significant explosive eruption. Volcanic eruptions vary widely in strength, on the one extreme there are effusive Hawaiian eruptions, which are characterized by lava fountains and fluid lava flows, which are typically not very dangerous. On the other extreme, Plinian eruptions are large, volcanoes are not bound to one eruptive style, and frequently display many different types, both passive and explosive, even the span of a single eruptive cycle. Volcanoes do not always erupt vertically from a crater near their peak. Some volcanoes exhibit lateral and fissure eruptions, many Hawaiian eruptions start from rift zones, and some of the strongest Surtseyan eruptions develop along fracture zones.
Scientists believed that pulses of magma mixed together in the chamber before climbing upward—a process estimated to several thousands of years. But Columbia University volcanologists found that the eruption of Costa Rica’s Irazú Volcano in 1963 was likely triggered by magma that took a route from the mantle over just a few months. The volcanic explosivity index is a scale, from 0 to 8 and it is used by the Smithsonian Institutions Global Volcanism Program in assessing the impact of historic and prehistoric lava flows. It operates in a way similar to the Richter scale for earthquakes, the vast majority of volcanic eruptions are of VEIs between 0 and 2. Volcanic eruptions by VEI index Magmatic eruptions produce juvenile clasts during explosive decompression from gas release, Hawaiian eruptions are a type of volcanic eruption, named after the Hawaiian volcanoes with which this eruptive type is hallmark. Hawaiian eruptions are the calmest types of events, characterized by the effusive eruption of very fluid basalt-type lavas with low gaseous content