Volcanoes are one of the most terrifying natural phenomena on Earth because they disrupt lives and take many lives with them.Besides the volcanoes themselves, the effects of the volcanic eruptions are felt by people through ash falls, floods caused by lava flows and debris avalanche routes, destructive hydrothermal explosions like those that built Hawaiʻi’s Mauna Loa, tsunamis, and lahars when rivers block up behind volcanic edifices during volcanic eruption events.Earth’s crust is made up of huge pieces called tectonic plates. The San Andreas Fault in California is one of the most active faults on Earth. Earth’s crust is constantly moving. The movement of the plates causes earthquakes.Ash flow tuffs form the bulk of the exposed rocks around the caldera. These rocks were deposited due to a large explosive eruption that occurred during the past several thousand years.The last major eruption at caldera volcano occurred about 1,100 years ago and produced ash flow that covered much of the surrounding area.A single eruption of this magnitude typically recurs every 500-1,000 years at caldera Volcano in the Earth’s history. The next major eruption could occur at any time.Let us learn more about caldera eruptions here.Location Of Caldera VolcanoCalderas form after a volcanic eruption when the magma chamber empties and the roof of the chamber collapses.All of the world’s volcanoes are composed of lighter-colored, silica-rich rocks like andesite, dacite, and rhyolite. These cause explosive eruptions, which means that they tend to eject many gases and rock fragments into the air during volcanic eruptions.The gases erupt and form ash clouds that can spread for hundreds or thousands of kilometers.The caldera is about 31 mi (49.8 km) long, 13 mi (20.9 km) wide, and 1,640 ft (499.8 m) deep. It lies between the Didgori Range to the southeast and the Avchala Range to the northwest, near Shatili in northwest Georgia.Volcanic fields are areas where volcanoes are found close to each other. Caldera volcanoes tend to occur in these fields.The most notable volcanic field in the United States with caldera volcanoes in the Yellowstone Plateau. Other examples of a volcanic field include the Long Valley Caldera in California and the Valles Caldera in New Mexico.Caldera Volcano FormationThe most important event in this phase of the caldera’s history began about 6,000 years ago when violent explosive eruptions hurled an estimated 6 cubic mi (25 cubic km) of magma out of the Earth.Nowadays, erosion has shaped this depression into a roughly heart-shaped area with gentle slopes on three sides and a rock cliff on the fourth side; this cliff is known as Kartskhi (Kartskhe means ‘heart’ in Georgian). This feature gives Khrami its alternative name, ‘cliff-hanger.‘On the northeastern flank of this caldera lies the Khrami lakes. These lakes were created by a mudflow that occurred over 10,000 years ago. This event created a large block of solidified mud half a mile wide and over 300 ft (91.4 m) thick in some places.Less than 1,500 ft (457.2 m) away from the rim of the caldera volcano, this feature forms a natural dam across the Kasani River.The enormous pressure on the bottom of this mud block has led to several collapses, which have created massive slides in recent times as well because it has been at least 7,500 years since one of these slides happened.The town of Khrami sits at the foot of this crater, and several mudflows have reached as far as it. One massive slide killed more than 800 people in 1783. Since then, many earth dams have been built to prevent catastrophe from happening again.Unfortunately, most of these dams have already deteriorated because they were constructed hastily after the 1783 event.Characteristics Of Caldera VolcanoGeologically, this is a unique feature in the world. Erosion and volcanic activity have carved out a gigantic circular depression on the side of a half a mile-wide mountain. The caldera’s rim stands around 1,400 ft (426.7 m) above the surrounding plain. Only half of this volcano is composed of rock; soaring mudflows have carved out the other half.The caldera has long been known to the local population of this area. So many mudflows have killed people here is a well-known local legend. Today, the population lives in relative safety and maintains as much farmland as possible.After Georgia’s independence, seismologists at the Georgia Institute of Technology have recorded several earthquakes within a radius of 6 mi (9.6 km) outside the caldera.Most of these earthquakes are microquakes, which are relatively common in this region; however, one microquake caused a piece of concrete to fall from Kartskhi Cliff, while another earthquake was often felt by people living there.This event occurred in the summer of 1996, and it was so powerful that it forced scientists to search for evidence of possible volcanic activity near this caldera.The government also built a new cable car system, which brought visitors directly up to the cliff for the first time.However, there is no clear indication yet that this side of the mountain will erupt any time soon. If the caldera volcano explodes, devastating mudflows will reach much farther than Khrami (’the city’ in Georgian).Parts of Tbilisi would be overwhelmed by mud. Of course, all animals and human beings would be buried alive under millions of tons of Earth.Types Of Caldera VolcanoCalderas can be classified according to their shape, location, cause, and size. They can also be classified according to their host lithology (the rocks they are embedded in). Calderas occur in volcanic, sedimentary, and even tectonic settings.Another interesting feature of this caldera is its two lakes on its northeastern flank. One of these lakes is called Sheshele Kari (meaning the stone lake), and the other is called Sheshele Dami (meaning the stone dam).Both lakes were formed by mudflows that occurred thousands of years ago; however, the dam has deteriorated significantly because of erosion over the last few centuries.A Cherokee legend tells about the volcano and the explanation given for its strange name: ‘Bisunti’ means this in the Cherokee language.According to their legend, it is believed that the creator of all things decided to punish humans for their dissimilarity by creating a giant wall inside the mountain; this wall had been designed to separate men and women.After they were divided, they were forced to create different languages. This was all done as a punishment by the creator, who dubbed this event the great separation. After it was finished, everyone on Earth spoke different languages.The side of the mountain which is facing the river, especially along its edge where the cliff is, is covered by chunks of rock. One of them, Kartskhi (the stone heart, crossing point or Greek: σάϕρπεια), is a large piece of granite that has been formed by mudflows from the lake on top.At one time, during an earthquake, it was believed that a river was flowing beneath this rock, but this turned out to be incorrect (there are no rivers beneath it). When this area was visited in 1995 for the first time, Khrami geologists said that these formations were due to erosion processes.Did You Know…Caldera volcanoes are some of the world’s largest and most powerful and active volcanoes.The magma chamber of a caldera volcano is often several times larger than that of a traditional volcano.A shield volcano is a type of volcano with a wide, shallowly sloping profile and is typically composed of basaltic lava flows. Shield volcanoes are the largest type of volcanoes on Earth.The name ‘shield volcano’ comes from its resemblance to a warrior’s shield. The eruptions of shield volcanoes are usually gentle, although some can be explosive.Crater lake caldera is a volcanic crater formed when the magma chamber of a volcano is emptied. The magma chamber is the layer of the Earth where molten rock (magma) is stored. The chamber empties when the magma erupts from the crater lake caldera, and a large crater is left behind.A Yellowstone caldera is a volcanic feature found in many parts of the world. The Yellowstone national park is home to the caldera of the Yellowstone supervolcano.The caldera floor comprises a thick pile of fragmented, welded andesitic to rhyolitic lava blocks, bombs, and ash.The caldera collapse that created the Miocene Santorini Caldera was so powerful that it created a tsunami in the Mediterranean Sea.A caldera forms when a portion of the Earth’s surface collapses, causing the magma chamber below to empty.A volcanic caldera is a cauldron-like depression that forms following the eruption of a volcano.Volcanic vents are openings in the Earth’s surface from which molten rock, ash, and gas escape. When it is below the surface, the molten rock, called magma, can become lava flow or explosive eruptions.A summit caldera is a volcanic feature that forms when the enormous eruption of a volcano destroys the summit of the mountain, leaving a large hole in the ground.A magma reservoir is a body of molten rock beneath the Earth’s surface.Cinder cones, lava domes, shield volcanoes, and stratovolcanoes are all types of caldera volcanoes. Cinder cones, specifically, are small, steep-sided volcanoes made up of loose ash and cinders.Tuff cones are a type of cinder cone that is made up of solidified lava rather than ash. An Indonesian volcano of this type is Mount Merapi, erupting sporadically since 1548.Dissolved gases in magma can become so much lighter than the surrounding rock that they can cause the magma to explode.Mauna loa is a shield type, which means that it is wide and has gentle slopes. The biggest volcano in the solar system is Olympus Mons on Mars.
Volcanoes are one of the most terrifying natural phenomena on Earth because they disrupt lives and take many lives with them.
