“Volcanoes are awesome manifestations of the fiery power contained deep within the Earth.” (National Geographic) They are easily one of the most amazing natural processes on our planet. Volcanic eruptions are mesmerizing to watch and one can only wonder how and why these happen. “Volcano” is a general term to describe horrific explosions from the ground. In actuality, there are many different volcanoes and no volcano is like another. Because of the great diversity we can classify volcanoes into four major categories: cinder cones, lava domes, shield volcanoes and stratovolcanoes.
Cinder cones are the smallest and most common of the four classifications of volcanoes. These volcanoes form when a ‘vent’ erupts and throws molten lava, tephra and rock into the air. When these particles fall back to Earth, they accumulate around the vent. Each time the vent erupts more particles fall and build up the sides. After a small amount of time, the eruptions stop and the end result is a Cinder cone. Over many years, the vent may erupt again and keep building up the volcano. Cinder cones are easy to identify with very steep, straight sides and a crater at the top, creating a cone shape. The sides are very similar to the angle of repose, they can range from 30O to 34O. As said before, these volcanoes are very small and usually only grow to be a maximum of 250 meters in height and 500 meters in diameter.
Lava domes are vicious volcanoes. They are formed when thick magma erupts from the ground and piles up around the vent. These volcanoes can grow in two different styles. When the lava dome grows by endogenic dome growth, the inside of the volcano expands so that new lava can flow and settle inside of it. Exogenic dome growth happens when lava ...
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...of these volcanoes begins when the oceanic crust is pushed under the continental crust or another oceanic plate. When water flows from the upper oceanic crust to the asthenosphere, magma is pushed towards the top of the vent. Underneath the volcano, the magma sets in a place called the magma chamber. As soon as certain amount of magma and gas is trapped in the magma chamber, the volcano erupts with a large explosion. Stratovolcanoes are the ideal volcano. They are identified by gradual slopes that begin at the bottom and work their way up to steeper slopes at the top of the volcano.
Though there are many volcanoes in the world, one that has been on high watch for the past 4 years is Mount Merapi. This stratovolcano is located in Indonesia and is split by the borders of Central Java and Yogyakarta. Over the last two decades, this volcano has been extremely active.
Mount Tambora, located on the Island of Sumbawa, Indonesia is classified as a Stratovolcano. Also known as a composite volcano, Tambora is a tall conical volcano (cone like structure) where layers of the walls are built by hardened lava and volcanic ash. The term composite is used to describe the volcano due to the composite layered structure built from sequential outpourings of eruptive materials1. Among the most common types of volcanoes, Tambora also shares its destructive prowess with best-known volcanoes such as Krakota (1883) and Vesuvius (79 A.D). The Island of Sumbawa is located in the middle of the Lesser Sunda Islands chain (a group of islands in the southern Maritime Southeast Asia) and is in the province of West Nusa Tenggara3. A map of Mount Tambora is shown in Figure 1 to provide a better perspective of its location. Interestingly enough, Tambora forms its own peninsula on Sumbawa, known as the Sanggar Peninsula. In April of 1815, after years of dormancy, Mount Tambora erupted with great intensity, approximately 7 on the volcanic explosivity index, which is shown in Figure 2. It has been estimated that the eject volume of Tambora was 160 cubic kilometres, which represents the largest volcanic eruption in recorded history. The death toll has been projected to be at least 71,000 people, of who over 15% were killed directly from the eruption1. The remaining 75% have been thought to succumb to starvation and disease, as the eruptive fallout decimated the agricultural industry in the region. Following the eruption, a volcanic winter ensued. As sun become less abundant due to clouds of ash, crops and livestock perished. Please note that all definitions appearing in the footnotes are either taken from already referenced so...
Mount Vesuvius is located in the Bay of Naples in Southern Italy. Its Latitude and Longitude is 40.8224° N, 14.4289° E. It is a stratovolcano and has a height of 1277 meters (1490 feet) and base of 48 kilometers (30 miles). Mount Vesuvius has erupted over 30 times and has a repose time that can last for months or even years between eruptions. Its eruptions are explosive and is dominated by pyroclastic flows. The eruption materials are usually an ash cloud with lightening that spews out dense ash falls. The lava can shoot up to 4km into the air. The most famous eruptions of Mt. Vesuvius were in 79 A.D. which destroyed the cities of Herculaneum and Pompeii. The cities were covered in 20 feet of volcanic debris. The estimated death toll was over 1000 people. The
Mauna Loa is Earth’s largest volcano and most massive mountain as it takes up nearly half of the flourishing landscape of the island of Hawai’i. This island is actually made up of five volcanoes, Kohala, Mauna Kea, Hualalai, Mauna Loa, and Kilauea, all in such close proximity that they fused together to form one whole island. Mauna Loa is located in the south central area of Hawai’i, in the Hawai’i Volcanoes National Park and its coordinates are 19°5' N, 155°6' W. It is 13,680 ft above sea level, but if one measures from its true base on the ocean floor, it is estimated to be 30,080 feet tall. Its name is quite fitting as it means “Tall Mountain”.
Kilauea is the youngest volcano on the Big Island of Hawaii. Still active, there have been 34 eruptions since 1983. Kilauea is a shield volcano, meaning it covers a wide range of area, and has sloping sides. Kilauea is usually confused as being a smaller part to the neighboring Mauna Loa volcano, but it has it’s own lava flow system which makes it special to the Hawaiian islands. The history of eruptions from Kilauea is lengthy and the volcano’s name actually means, “spewing.” The oldest documented samples of lava date back almost 3,000 years and the oldest human documented eruption happened in 1823.
Basalt forms due to the partial melting of the layer of the mantle called the asthenosphere. The asthenosphere is the plastic zone of the mantle beneath the rigid lithosphere. Mantle plumes coming from the mesosphere can cause the asthenosphere to melt with heat or even if pressure decreases, which is called decompression melting (Richard 2011). The magma that forms from this melting is mafic magma that solidifies once it reaches the earth’s surface and cools quickly. The above process mainly occurs mainly during intraplate igneous activity which is the main explanation for volcanic activity that occurs a long distance away from a plate boundary. If the tectonic plate above the mantle plume is moving it can create a string of volcanic activity such as in Hawaii. See Fig 2.
Like most of the other volcanoes in the Cascade Range, St. Helens is a great cone of rubble, consisting of lava rock interlayered with ash, pumice and other deposits. Volcanic cones of this internal structure are called composite cones or stratovolcanoes. Mount St. Helens includes layers of basalt and andesite through which several domes of dacite lava have erupted. The largest of the dacite domes formed the previous summit; another formed Goat Rocks dome on the northern flank. These were destroyed in St. Helens' 1980 eruption.
Volcanoes. The naturally forming landforms that can look remarkably beautiful. Gentle slopes, or high rising heights with snow caps and greenery that seems to attract many tourists and sightseers around the world. These magnificent landforms can also cause major destruction and can produce forces that can explode, burn, and create a great deal of damage. Two of these extravagant wonders of the world is the Mount Saint Helens composite volcano in Washington, US, and the Mauna Loa shield volcano in Hawaii, US. These landforms have a eruption history of many colors. One has a great power in eruption, but another has a eruption that is quiet and gentle. In comparing these two volcanoes there are many likes, and dislikes, to consider. So the following
Stories about volcanoes are captivating. Myths come in different versions, but all of them are capable of capturing yours, and everybody’s imagination.
Super volcanoes are formed when magma rises from the mantle to create a scorching reservoir in the Earth's
Volcanoes are one of natures most interesting and dangerous phenomenons. The way volcanoes operate can be understood, on a basic level, by just some simple physics and chemistry, this paper will investigate and explain some of the basic physics that govern the behavior of volcanoes.
Convection currents deep in the mantle of the earth, begin to well up towards the surface. As the pressure increases, it sets the crustal plates in motion. There are different kinds of mountains - Volcanic, Folded, Fault-block, and Dome mountains. Volcanic mountains are formed when magma comes up through cracks in the Earth’s crust and explodes out of lava and ash. The Hawaiian volcanoes, Mt. Hood, Mt. Etna, Vesuvius, and Mt. Saint Helens is an example of volcanic mountains.
Volcanoes can be one of the most destructive forces on Earth. It is estimated that some
The Mauna Loa volcano is located in Hawaii and means "Long Mountain" in Hawaiian. It is a giant, basaltic shield volcano. It is one of the largest volcanoes and mountains in the world and has been called the "monarch of mountains". It has an estimated volume of 9,600 cubic miles and takes up half the land of Hawaii. It extends about 120 km starting from the southern tip of the island to the northern region. It is 97 km (60 miles) long, 48 km (30 miles) wide, and is 8,742 km (28,680 miles) high from the base on the sea floor to the top. The slopes are steeper than 12 degrees and about 4 degrees at the top of the volcano. Mauna Loa formed about half a million years ago and in the middle stages of forming into a shield volcano where lava flows to form a sloped and broad flat domed volcanic cone. Along with Mauna Kea, the Mauna Loa volcano is responsible for the creation of the Hawaiian Islands. Mauna Loa has erupted thirty-three times since 1843 and is known as one of the most active volcanoes in the world today. The last eruption was 1984 and lava flowed within 4 miles of the city of Hilo. This shows that it is dangerous to live anywhere near Mauna Loa and that it poses as a threat to anyone living near it because it has a very high possibility of erupting within a very short span of time. Below is a picture of Mauna Loa taken from a bird's eye view.
Mount Vesuvius is a volcano located in southern Italy, near the bay of Naples and the city of Naples. It is the only active volcano on the European mainland. Vesuvius rises to a height of 1277 m (4190 ft). Vesuvio (Vesuvius) is probably the most famous volcano on earth, and is one of the most dangerous.