Volcano Eruption

A Volcanic Eruption is the release of hot gases, molten rock, and hot rock fragments through a volcano. A volcano is a vent in the crust of a planet or satellite. Volcanic eruptions can result in catastrophic property and human loss. Volcanic eruptions might even be almost harmless, like most volcanoes in Hawaii. They can also be extremely devastating, as when Pompeii was destroyed by Vesuvius’ explosion in 79 CE. In this article, we will look into the definition, causes, types, and effects of volcanic eruptions. We will also explore the recent volcano eruptions.

What is Volcanic Eruption?

A rupture in the Earth’s crust caused by tectonic plate movement is known as a volcano eruption. Molten magma is forced onto the Earth’s surface by this explosion, which occurs in the core of the planet. Lava is another name for this molten magma, which has a temperature so high that it may turn anything into ashes when it comes into contact with a surface, an object, or a human body.

Volcanic eruptions might occur from the volcano’s side branches or the summit. Certain eruptions are explosive explosions that send huge quantities of rock and volcanic ash skyward, resulting in extensive destruction and many fatalities. While some lava flows are roaring, others are peaceful. Many complex varieties of volcanic eruptions have been recognized by volcanologists. These are typically named depending on where that particular type of eruption has happened. Certain volcanoes may only produce a single type of eruption during an active time, whereas others may produce multiple types in a sequence of eruptions.

Mechanism of Volcanic Eruption

Different layers of the Earth’s mantle within the crust are divided based on unique seismology. These include the lower mantle, which is located between 660 and 2891 km, the transition zone, which is located between 400 and 660 km, and the upper mantle, which is located between 8 and 35 km to 410 km. Between the crust and the mantle, the environment drastically changes.

• Some rocks slowly melt due to the extreme heat deep within the earth, transforming into a thick, flowing substance called lava. Lava rises to the surface and gathers in magma chambers because it is lighter than solid rock. Both the temperature and pressure increase significantly, reaching up to 1000℃. Within the Earth’s crust, this molten, viscous rock gathers into huge chambers.
• Magma searches for fissures and weaknesses in the mantle because it is lighter than the surrounding rock and rises toward the surface. Some magma eventually finds its way through surface cracks and vents. Thus, there is a volcanic explosion, and the lava that is released is the resulting magma.
• When it eventually reaches the surface of a volcano, it blasts from the peak. The molten rock is called magma when it is below the surface and explodes as ash when it rises. With each eruption, ash, lava, and rocks are deposited across the volcanic vent. The viscosity of the magma mostly determines the type of eruption. When the lava flows quickly, it spreads far and forms wide shield volcanoes. It takes on the characteristic shape of a cone volcano when it gets too thick. Lava domes are created when exceptionally thick lava builds up inside a volcano and explodes.

Volcanic Eruption Example

A good example of a volcanic eruption is the Mount St. Helens eruption in Washington. The magma in this form of eruption shoots skyward and fragments into tiny bits known as tephra. Tephra can be as little as ash grains or as large as stones the size of houses.

Another example of volcanic eruption is Barren Island Eruption in India. On August 24, 2005, the volcano on Barren Island erupted. India’s Barren Island, one of the Andaman Islands, is situated above the fault whose movement caused the tsunami that struck on December 26, 2004. It is a stratovolcano made of volcanic ash, lava, and broken rock.

Volcanic Eruption Types

The chemistry of the magma, temperature, viscosity, volume, presence of groundwater, and water and gas concentration are some of the variables that affect the types of volcanic eruptions.

The six types of volcanic eruptions are as follows:

• Hawaiian and Strombolian Eruptions: The Strombolian eruption produces explosions caused by broken lava, while the Hawaiian eruption produces fire fountains.
• Plinian and Subplinian Eruptions: Plinian eruptions can reach a height of 20–35 km, but Subplinian eruptions can reach up to 20 km.
• Hydrothermal Eruption: Ash is released during hydrothermal eruptions; magma is not present. Their energy source is the heat produced by hydrothermal systems.
• Phreatic Eruption: This is caused by interactions between the water and the magma’s heat. There is only ash in these eruptions instead of magma.
• Phreatomagmatic Eruption: This type of eruption occurs when water and freshly generated magma interact.
• Vulcanian Eruption: These eruptions can reach heights of up to 20 kilometers and last for a brief time.

Causes of Volcanic Eruption

Volcanic eruptions have these three primary causes:

1. The Magmatic Buoyancy

Magma buoyancy creates a background overpressure that can gradually rise. This overpressure either prepares the magma chamber for a subsequent trigger or may eventually cause a super-eruption on its own.

2. Dissolved Pressure in the Magma

Nearly all magmas at Earth’s depths have gas dissolved in the liquid; however, as magma rises toward the surface, pressure decreases and the gas separates into a vapor phase. This is comparable to highly pressurized bottles of fizzy drinks.

3. Increased Pressure in the Magma Chamber

Pressure rises when magma fills the chamber. Magma can burst through the crust and erupt as a volcano if the pressure builds up sufficiently. Volcanic eruptions typically take place above subduction zones.

Volcanic Eruption Effects

The following are the effects of volcanic eruption:

• Flooding is one of the major effects of volcanic eruptions.
• Mudslides are also caused by volcanic eruptions.
• In woodlands, it also starts wildfires.
• Power shortages can also cause by volcanic eruptions.
• Also, it contaminates drinking water.
• Besides human deaths, it may also result in animal deaths.
• Moreover, a volcano eruption can seriously harm the surrounding area and the ecology.
• Because of the ash cloud that forms within it, it may also result in air pollution.

Volcanic Eruption in Iceland

Iceland is located on a divergent tectonic plate boundary, the Mid-Atlantic Ridge, and it is also situated above a hot point, which results in regular volcanic activity. Eldgja, the site of the greatest known lava eruption in human history, is one of the over thirty volcanoes that are known to have erupted during the Holocene epoch.

There are over thirty active volcanic systems on the island, which are made up of tectonic fissure systems, stratovolcanoes, and core volcanoes (which are typically protective volcanoes with a magma chamber beneath them). Since Iceland was settled in AD 874, eruptions have occurred in thirteen different volcanic systems. Grimsvotn is the most active of these 30 active volcanic systems. Iceland’s volcanoes have created one-third of the world’s total lava output in the last 500 years.

Volcanic Eruption Japan

Over the previous 1,300 years, there have been 130 major eruptions from Japan’s 38 volcanoes. More than 4,900 people died. The “Tokachi” eruption on May 24, 1926, was the worst volcanic eruption in terms of fatalities, destroyed homes, and monetary losses. There were 144 fatalities.

In Japan, there are 67 volcanoes, of which 55 are thought to be active. Off the coast, there is another active undersea volcano.

Volcanic Eruption in India

The island of Barren Island is situated in the Andaman Sea. It is the only active volcano in the Indian subcontinent and the only one in a chain of volcanoes. It extends from Sumatra to Myanmar. It is also the only one with proven activity. Situated approximately 138 kilometers (86 mi) northeast of Port Blair, the territorial capital of the Andaman and Nicobar Islands, it is a part of the Indian Union territory.

A volcanic belt that borders the Indian and Burmese tectonic plates encircles this volcanic island. Aside from volcanic seamounts like Alcock and Sewell, the area is inhabited by a dormant volcano called Narcondam Island. This 2 km (1.2 mi) wide caldera was created by the Pleistocene collapse of a primordial cone of a stratovolcano. All historical and contemporary eruptions are contained within and around an active polygenetic cinder cone.

Volcano Eruption 2023

According to the Smithsonian / USGS Weekly Volcanic Activity Report (WVAR), the current state of 47 volcanoes in continuous eruption as of December 15, 2023, was reported. While “continuing” does not always imply continuous daily activity, it does denote at least occasional eruptions without a three-month or longer pause. Some of the eruptions are mentioned below:

1. Hunga Tonga-Hunga Ha’apai Volcano

The Hunga Tonga-Hunga Ha’apai volcano is located in the western South Pacific Ocean, to the west of the Kingdom of Tonga’s principal populated islands. Record-breaking temperatures have been recorded in 2023. Scientists believe that Hunga Tonga-Hunga Ha’apai’s undersea volcanic eruption in the South Pacific in 2022 could be one of the causes of this. Along the Tofua Arc, a section of the greater Tonga-Kermadec volcanic arc, it is one of the twelve verified undersea volcanoes.

2. Mount Etna Eruption

On May 21, 2023, Mount Etna, the most active volcano in Europe, erupted, causing visibility to be so poor that flights from Catania, the major city in eastern Sicily, had to be grounded. Situated between the cities of Messina and Catania in the Metropolitan City of Catania, Mount Etna is an active stratovolcano on the east coast of Sicily, Italy.

3. Ruby Seamount Eruption

Ruby Seamount is a volcanic seamount that is now active, located around 50 kilometers northwest of Saipan in the Pacific Ocean’s Northern Mariana Islands regions. It is located in an area where arc volcanism is being produced by the Pacific Plate subducting beneath the Philippine Sea Plate. Submarine eruptions took place in 1966 between October 11 and 23, 1995, and on September 14, 15, and 16, 2023. They lasted for almost 12 hours each.

Conclusion

Volcanic eruptions are breaks in the Earth’s crust that expose the magma that is underneath the surface of the globe, causing hot gases, molten lava, and small pieces of rock to explode out of them. The temperature is so high deep inside the earth that some rocks slowly melt and transform into lava, a thick, flowing substance. Magma rises to the surface because it is lighter than the surrounding solid rock and gathers in magma chambers when it cools. Eventually, fractures and vents allow some of the magma to break through the surface of the earth. Consequently, there is a volcanic explosion, and the lava that is released is the resulting magma.

FAQs – Volcano Eruptions

1. What is Volcanic Eruption?

The release of gases, broken rock, and/or molten lava from within the Earth through a vent onto the surface or into the atmosphere is known as a volcanic eruption. Volcanic eruptions can result in catastrophic property and human loss.

2. Where do Volcanoes Erupt and Why?

The margins of tectonic plates are site to 60% of all active volcanoes. The majority of volcanoes are situated along the Pacific Ocean’s “Ring of Fire,” a belt. Certain volcanoes, such as those that compose the Hawaiian Islands, are found near “hot spots” in the interior of plates.

3. What was the first Volcano Eruption in the World?

The eruption of Mount Vesuvius in 79 AD is the initial recorded case of a volcano explosion that has been definitively documented by Roman author Pliny the Elder. In Catalhoyuk, Turkey, archaeologists have discovered cave drawings that appear to show a volcano erupting and date from roughly 6900 BCE.

4. What are the 5 Causes of Volcanic Eruption?

In general, a volcano has to accumulate enough magma in its chamber for an eruption to happen. The eruption must then be set off by something. That might be a landslide that clears debris from a volcano’s summit, an infusion of fresh magma into the chamber, or an accumulation of gasses inside the volcano.

5. Is Volcanic Eruption a Disaster?

‘Natural disasters’ do not include volcanic eruptions or other catastrophic phenomena. Even if the term “natural disaster” is frequently used, it has several drawbacks. By thinking that the incident would occur anyway and that there is little that can be done to prevent it, the term “natural” minimizes the part that humans played in the catastrophe.