Table Of contents Pages I. What is a Hotspot? 1 II. Hotspot Volcanism 1 III. What causes Hotspot Volcanoes? 2 IV. Examples and Locations of Hotspots 2 V. What is Tectonic plates? 3 VI. Movement of Tectonic plates Over time 4 VII. Super volcanoes 7 VIII. What makes a volcanoes super? 7 IX. Super volcanoes and Super eruptions 8 X. Super Volcanoes past and present 9-12 I.What is a Hotspot? …show more content…
Tuzo Wilson in 1963, it states that hot spot volcanoes are created by exceptionally hot areas fixed deep below the Earth’s mantle. Recent scientific findings predict that these hot spots may be found at more shallow depths in the Earth’s mantle and may migrate over geologic time rather than being fixed in the same spot. II. HotSpots Volcanism Volcanoes caused as a result of formation of hot spots are called Hot spots volcanism. This kind of volcanoes is different from other volcanoes that occurs usually at the boundaries of Earths tectonic plates, rather it occurs at centers called Mantle Plumes. As the plumes head reaches the lithosphere, it spreads into a mushroom shape that reaches roughly 500 to 1000 kilometers. These mushroom shapes are called diapirs. Most Hot spots volcanoes are Basaltic in nature, so they are less explosive than subduction zone volcanoes. III. What causes HotSpot Volcanoes? According to the still prevailing theory, most of it not all hotspots are believed to be the result of mantle plumes – bodies of warmer , and thus lighter material within that rises by …show more content…
About 74,000 years ago, Toba erupted and ejected several thousand times more material than erupted from Mount St. Helens in 1980. Some researchers think that Toba 's ancient super eruption and the global cold spell it triggered might explain a mystery in the human genome. Our genes suggest we all come from a few thousand people just tens of thousands of years ago, instead of from a much older, bigger lineage as the fossil evidence testifies. Both could be true if only a few small groups of humans survived the cold years following the Toba eruption. 5. Taupo Caldera Taupo Caldera is listed (or ranked) 5 on the list The World 's 6 Known Supervolcanoes Photo: Erick Opena New Zealand 's Taupo caldera has been filled by water, creating what many describe as one of the world 's most beautiful landscapes, but the lake itself was created by a massive eruption 26,500 years ago. The caldera — the collapsed and subsided basin left after the huge eruption became today 's lake. But Taupo is not dead. The 485-square-mile caldera let loose again in the year A.D. 181, with estimates of ash and magma reaching as high as 22 cubic miles. Today, there are plenty of signs of current volcanic activity in the form of hot springs and venting. 6. Aira
Island arcs form as oceanic plate subducts under oceanic plate. Volcanism is concentrated in an arc of volcanoes, generally approximately located above the leading edge of the subducting plate. A trench often forms where the slabs meet and subduction begins. On the non subducting slab a series of basins form, with a fore-arc basin nearest the subduction/trench, then the main arc, and a back-arc basin on the far side (Mitchell and Reading, 1971; Frisch, Meschede and Blakey, 2010).
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...
Volcanoes have always been a mysterious wonder of the world. Volcanoes have shaped the landscape and the very ground that we all live on. People have written stories of their disastrous eruptions, and painted their marvelous shapes on canvas. The essay will outline some of the more famous volcanoes and how they have impacted are history. Mount Vesuvius that destroy the great city of Pompeii, Krakatoa they spewed deadly ash on small village town, and Mount St. Helen, the only volcano in my own country to every erupt during my own time period.
Mauna Loa is located on a hot spot in the Pacific Ocean. It is not near a plate boundary, in fact it is 3,200 km from the nearest plate boundary, and is situated in the middle of the Pacific tectonic plate. This is actually a rarity, as 90% of volcanoes are along a tectonic plate boundary. A hot spot occurs where long, stationary vertical pools of magma rise up and towards the plate. Movement of the tectonic plates above the hot spot created Mauna Loa, along with the other Hawaiian volcanoes. The older Hawaiian Islands were once above this stationary hot spot, but have been carried northwest by the slowly moving Pacific plate. As the plate moves, it carries the previously formed, older, volcanoes with it, creating a trail of younger, new volcanoes behind. The islands are lined up along the Hawaiian Ridge-Emperor Seamounts chain, which is 3,750 miles and includes Kauai, Maui, Oahu and Hawai’i, from north to south, respectively. There are around 80 volcanoes in this chain; most of them underwater, consequently the term seamount refer to submarine volcanoes. Three volcanoes of Hawai’i, Mauna Loa, Kilauea and Loihi seamount, are all currently sharing the Hawaiian hot spot. Although, recent evidence has shown that all three volcanoes use have separate plumbing systems to expel the lava from the pool of magma deep below them. It has also been suggested that Loihi is slowly moving Mauna Loa from the center of the island, thus shifting directly over the hot spot. The closer to the hot spot a volcano is, the more active it will be. The Hawaiian hot spot has laid down layers of lava, building up enormous islands from the ocean floor.
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.
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 There is no exact definition for a super volcano, but the expression is often used to refer to volcanoes that have produced extraordinarily large eruptions in the past. When one of these large eruptions occurs, a huge amount of material is blasted out of the super volcano, leaving a massive crater or caldera. A caldera can be as much as forty or fifty miles wide. At Yellowstone, the caldera is so big that it includes a fair amount of the entire park. In effect, it is so big that at first scientists didn't see the state a caldera had until it was photographed from space.
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.
From modern examples and records we know that volcanic activity can set of a chai...
The earliest outcropping volcanic deposits date back to about 25,000 years ago. The lavas observed at a -1125 m bore-hole are about 0,3-0,5 million years old. It is known for the first eruption of which an eyewitness account is preserved, in 79 AD. Geologically, Vesuvio is unique for its unusual versatility. Its activity ranging from Hawaiian-style release of liquid lava, fountaining and lava lakes, over Strombolian and Vulcanian activity to violently explosive, plinian events that produce pyroclastic flows and surges.