Showing posts with label erruptions. Show all posts
Showing posts with label erruptions. Show all posts
Sunday, February 21, 2010
Volcanoes - Their Formation and When They Erupt
Volcanoes received their name after the Roman god of fire, Vulcan. Ancient Romans believed that one volcano near Naples was the entrance into the underworld. In the Greek mythology Hephaistos had his forge underneath the volcanoes. When the gods were angry, people were punished by the fire of the erupting volcanoes. To placate the gods, people would throw sacrifice into the lava lakes, sometimes even human sacrifice.
The majority of close to 1500 active volcanoes on the earth are in the regions where the tectonic plate boundaries touch. To be considered active, the volcano must have been active during the last 1000 years. If there was no activity during that time, the volcano is considered extinct. Today, there are approximately 600 active volcanoes on land, mostly in Iceland, Hawaii, Java, the Aleutian Islands, Central America, Italy, and New Zealand. The incidence of volcanic eruptions on the sea floor is much higher.
When an oceanic plate collides with a lighter continental plate, the heavier plate slides underneath the lighter plate. This is called subduction. In this case, the part of the submerged plate melts. This fluid molten rock is called magma. The magma rises and spills onto the plate that is above it. When two plates drift away from each other, they create a rift in the earth's crust. In this case the magma also ascends. When this happens in the ocean, the magma forms new sea floor or volcanic islands. When it happens on land, it forms volcanic crests.
A volcanic eruption is often accompanied by release of liquid and gaseous material from the earth's interior. This material is concentrated from ten to one hundred kilometres underneath the surface. The temperatures at that depth may reach 1200 degrees Celsius. The molten rock collects in the magma chamber in the earth's crust. The concentrated magma is connected by means of a volcanic vent to the summit of the volcano. During a volcanic eruption, boulders, ash, dust, and gases are ejected. These phenomena may occur in the form of an explosion, when these masses are hurled high into the air above the volcano, or the lava just may slowly flow out of the volcano.
We recognise various types of volcanoes, in general by the type of lava. Shield volcanoes have a wide base and flat slopes, which are formed by lava flow. Lava flows far down the mountain until it congeals. Many so-called "hot spots" are shield volcanoes. An example of this type of volcanoes is Kilauea in Hawaii. In contrast, composite volcanoes (also called stratovolcanoes) have moderately steep sides formed by lava and ash. One of these composite volcanoes is Mount Fuji in Japan. Gaseous volcanoes are those that spew almost exclusively gases.
When the volcanic activity diminishes, quite often it leaves behind the so-called post-volcanic phenomena. These include hot springs and gases, and we may observe those in the form of geysers, fumaroles, and mudpots.
A volcanic eruption may cause a lot of damage. The eruption proper is less serious. The mudslides and floods, which in turn have negative impact on the population such as hunger or an onset of epidemics, are of far more serious nature. Another dangerous phenomena which may accompany volcanic eruptions are windstorms, heavy rains, and tornadoes, and may produce considerable damage.
It is seldom possible to predict a volcanic eruption. One positive side of volcanic activity is that it fertilizes the soil, uncovers ore deposits, and provides thermal energy from the hot springs, but this occurs only infrequently.
Volcanoes
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Article Source: http://EzineArticles.com/?expert=Karel_Kosman
The majority of close to 1500 active volcanoes on the earth are in the regions where the tectonic plate boundaries touch. To be considered active, the volcano must have been active during the last 1000 years. If there was no activity during that time, the volcano is considered extinct. Today, there are approximately 600 active volcanoes on land, mostly in Iceland, Hawaii, Java, the Aleutian Islands, Central America, Italy, and New Zealand. The incidence of volcanic eruptions on the sea floor is much higher.
When an oceanic plate collides with a lighter continental plate, the heavier plate slides underneath the lighter plate. This is called subduction. In this case, the part of the submerged plate melts. This fluid molten rock is called magma. The magma rises and spills onto the plate that is above it. When two plates drift away from each other, they create a rift in the earth's crust. In this case the magma also ascends. When this happens in the ocean, the magma forms new sea floor or volcanic islands. When it happens on land, it forms volcanic crests.
A volcanic eruption is often accompanied by release of liquid and gaseous material from the earth's interior. This material is concentrated from ten to one hundred kilometres underneath the surface. The temperatures at that depth may reach 1200 degrees Celsius. The molten rock collects in the magma chamber in the earth's crust. The concentrated magma is connected by means of a volcanic vent to the summit of the volcano. During a volcanic eruption, boulders, ash, dust, and gases are ejected. These phenomena may occur in the form of an explosion, when these masses are hurled high into the air above the volcano, or the lava just may slowly flow out of the volcano.
We recognise various types of volcanoes, in general by the type of lava. Shield volcanoes have a wide base and flat slopes, which are formed by lava flow. Lava flows far down the mountain until it congeals. Many so-called "hot spots" are shield volcanoes. An example of this type of volcanoes is Kilauea in Hawaii. In contrast, composite volcanoes (also called stratovolcanoes) have moderately steep sides formed by lava and ash. One of these composite volcanoes is Mount Fuji in Japan. Gaseous volcanoes are those that spew almost exclusively gases.
When the volcanic activity diminishes, quite often it leaves behind the so-called post-volcanic phenomena. These include hot springs and gases, and we may observe those in the form of geysers, fumaroles, and mudpots.
A volcanic eruption may cause a lot of damage. The eruption proper is less serious. The mudslides and floods, which in turn have negative impact on the population such as hunger or an onset of epidemics, are of far more serious nature. Another dangerous phenomena which may accompany volcanic eruptions are windstorms, heavy rains, and tornadoes, and may produce considerable damage.
It is seldom possible to predict a volcanic eruption. One positive side of volcanic activity is that it fertilizes the soil, uncovers ore deposits, and provides thermal energy from the hot springs, but this occurs only infrequently.
Volcanoes
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Article Source: http://EzineArticles.com/?expert=Karel_Kosman
Retiring in Nicaragua - The Natural Wonders of Volcanoes
An undeniable benefit of investing in Nicaragua real estate or buying a retirement property in Nicaragua is the opportunity to experience nature in a way that would be impossible in North America. Nicaragua is often referred to as 'the country of Lakes and Volcanoes' and for good reason. An impressive string of volcanoes also runs the length of the country.
You can climb both active and dormant volcanoes, swim in crater lakes, walk through the forested slopes, or take a peek over the rim into the crater of an active volcano. There are over a dozen volcanoes in Nicaragua with at least six being within an easy day trip of the real estate hot spot of San Juan del Sur, Nicaragua.
The Masaya Volcano (635m) is an active volcano located in Masaya Volcano National Park and is located approximately 80 miles from San Juan del Sur. A national park has been set up around the volcanoes, and within the park there is a paved road that leads to a crater. The park includes two volcanoes, the Masaya Volcano and the Nindirí Volcano, and five craters. Hiking through the reserve will also allow you to observe the spectacular landscape created by past eruptions.
The Masaya Volcano is the most accessible volcano in Nicaragua. There is also a visitor center with a little museum.
When the Apoyo Volcano (468m) last erupted, it left a huge 7 km-wide crater that gradually filled with fresh water. This lake, located between Masaya and Granada, is surrounded by the old crater wall. This spectacular lagoon can be easily reached by car from San Juan del Sur in 1.5 hours. It is the perfect spot for a day of swimming and relaxing.
The Mombacho Volcano (1,345m) is a huge dormant stratovolcano bordering Lake Nicaragua, close to Granada. Currently, the Mombacho Volcano is quiet and today a dense forest covers the slopes. The Mombacho Volcano is a very accessible volcano. The biodiversity of the Mombacho Volcano provides a wide selection of animals and plant species endemic to the volcano. Well maintained hiking trails have been set up, which offer a number of hiking options. In addition to amazing natural vegetation you can also find spectacular vistas along the trails.
Zapatera Island (629m) is an extinct volcano located inside Lake Nicaragua. Zapatera is a very small island and is inhabited by only a small group of people. Zapatera Island was inhabited by indigenous tribes and has many important archaeological sites. Ancient statues and artifacts have been found in great quantities on the island, and it is thought that many are still buried there. Although Zapatera offers some interesting archaeological sites, the island is not frequently visited. Visiting the island is possible but requires some effort.
Concepcion Volcano (1,610m) is a giant among the volcanoes in the land of volcanoes. The Concepción Volcano dominates the western side of Ometepe Island. Concepción is a cone-shaped stratovolcano. The most recent violent eruption occurred in 1986. The volcano continues to regularly emit gases and ash. Climbing the Concepción is challenging but can be worth the effort. Beautiful vegetation and spectacular views meet hikers on the way up. Along the way you will pass different types of vegetation. If you are lucky enough to climb on a clear day, you will be treated to awesome views. Ometepe Island can be easily reached from San Juan del Sur. However, if you intend to climb the volcano you should make plans to stay overnight on the Island.
Concepción Volcano shares the island of Ometepe with the Maderas Volcano (1,394m). Maderas is a dormant volcano with a wet tropical forest similar to the Mombacho Volcano. On the top of Madera you will discover a charming crater lake. There is no paved road to the crater and you will have to hike if you want to visit the lake. Maderas is much less steep than Concepción, but it is still a lengthy hike. The round trip should take approximately eight hours. Ascending this volcano is a once in a lifetime experience as it is likely the most beautiful of the all the volcanoes in Nicaragua.
For more information on the Land of Lakes and Volcanoes please visit Nicaragua Real Estate.
Jennifer A. Moore has been an investor in Nicaragua Real Estate since 2006.
Article Source: http://EzineArticles.com/?expert=Jennifer_A._Moore
You can climb both active and dormant volcanoes, swim in crater lakes, walk through the forested slopes, or take a peek over the rim into the crater of an active volcano. There are over a dozen volcanoes in Nicaragua with at least six being within an easy day trip of the real estate hot spot of San Juan del Sur, Nicaragua.
The Masaya Volcano (635m) is an active volcano located in Masaya Volcano National Park and is located approximately 80 miles from San Juan del Sur. A national park has been set up around the volcanoes, and within the park there is a paved road that leads to a crater. The park includes two volcanoes, the Masaya Volcano and the Nindirí Volcano, and five craters. Hiking through the reserve will also allow you to observe the spectacular landscape created by past eruptions.
The Masaya Volcano is the most accessible volcano in Nicaragua. There is also a visitor center with a little museum.
When the Apoyo Volcano (468m) last erupted, it left a huge 7 km-wide crater that gradually filled with fresh water. This lake, located between Masaya and Granada, is surrounded by the old crater wall. This spectacular lagoon can be easily reached by car from San Juan del Sur in 1.5 hours. It is the perfect spot for a day of swimming and relaxing.
The Mombacho Volcano (1,345m) is a huge dormant stratovolcano bordering Lake Nicaragua, close to Granada. Currently, the Mombacho Volcano is quiet and today a dense forest covers the slopes. The Mombacho Volcano is a very accessible volcano. The biodiversity of the Mombacho Volcano provides a wide selection of animals and plant species endemic to the volcano. Well maintained hiking trails have been set up, which offer a number of hiking options. In addition to amazing natural vegetation you can also find spectacular vistas along the trails.
Zapatera Island (629m) is an extinct volcano located inside Lake Nicaragua. Zapatera is a very small island and is inhabited by only a small group of people. Zapatera Island was inhabited by indigenous tribes and has many important archaeological sites. Ancient statues and artifacts have been found in great quantities on the island, and it is thought that many are still buried there. Although Zapatera offers some interesting archaeological sites, the island is not frequently visited. Visiting the island is possible but requires some effort.
Concepcion Volcano (1,610m) is a giant among the volcanoes in the land of volcanoes. The Concepción Volcano dominates the western side of Ometepe Island. Concepción is a cone-shaped stratovolcano. The most recent violent eruption occurred in 1986. The volcano continues to regularly emit gases and ash. Climbing the Concepción is challenging but can be worth the effort. Beautiful vegetation and spectacular views meet hikers on the way up. Along the way you will pass different types of vegetation. If you are lucky enough to climb on a clear day, you will be treated to awesome views. Ometepe Island can be easily reached from San Juan del Sur. However, if you intend to climb the volcano you should make plans to stay overnight on the Island.
Concepción Volcano shares the island of Ometepe with the Maderas Volcano (1,394m). Maderas is a dormant volcano with a wet tropical forest similar to the Mombacho Volcano. On the top of Madera you will discover a charming crater lake. There is no paved road to the crater and you will have to hike if you want to visit the lake. Maderas is much less steep than Concepción, but it is still a lengthy hike. The round trip should take approximately eight hours. Ascending this volcano is a once in a lifetime experience as it is likely the most beautiful of the all the volcanoes in Nicaragua.
For more information on the Land of Lakes and Volcanoes please visit Nicaragua Real Estate.
Jennifer A. Moore has been an investor in Nicaragua Real Estate since 2006.
Article Source: http://EzineArticles.com/?expert=Jennifer_A._Moore
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