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Around Rome Tours: 30 Interesting Facts About Pompeii

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Around Rome Tours: 30 Interesting Facts About Pompeii

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30 Interesting facts about Pompeii and Mount Vesuvius | Around Rome Tours

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30 interesting Facts About Pompeii and Mount Vesuvius 1.The city and people of Pompeii did not know that Vesuvius was a volcano, as it hadn't erupte-30-interesting-facts-about-pompeii-and-mount-vesuvius-art3

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Top 10 facts

1. Volcanoes are big holes that let out hot gasses, ash and magma from deep inside the Earth.

2. Many volcanoes are mountains, made up of layers of lava and ash.

3. Many volcanoes have several vents - a main one, and secondary ones that branch off the main vent. The volcano's main vent goes all the way down to the layer of magma in between the Earth's crust and mantle.

4. The Earth has three layers - the crust at the very top, then the mantle, then the core at the very middle of the planet.

5. There are three ways to describe a volcano and explain what it's doing - active, erupting, and dormant.

6. An extinct volcano is one that hasn't erupted in at least 10,000 years, and that scientists don't think will erupt again for a very long time.

7. The largest active volcano in the world is Mauna Loa, on the Hawaiian islands.

8. When a volcano erupts, magma comes up and out through the vents. Magma is called lava when it's outside the volcano.

9. Depending on how thick the magma is, volcanoes can be different shapes such as shield, composite or dome.

10. Ash from volcanoes is very good for growing things. It adds nutrients to the soil.

Did you know?

There are 1,500 active volcanoes in the world and about 50 volcanoes erupt every year!

Most volcanoes can be found in countries that have coastlines on the Pacific Ocean - this is called the Ring of Fire.

Gas, ash and magma can come out of volcanoes.

When magma flows out of a volcano, it's called lava.

Most of the gas that comes out of volcanoes is poisonous.

Some volcanoes are underwater!

There aren't any volcanoes in the UK. The largest volcano in Europe is Mount Etna in Sicily (Italy).

The word 'volcano' comes from 'Vulcan', the Roman god of fire

Volcano pictures

Have a look through the images in the gallery and see if you can spot the following:

The parts of a volcano © Anthony Bennett, Internet Geography

A volcano in Hawaii

Molten lava

A smoking crater in New Zealand

An eruption at Mount Krakatoa, between the islands of Java and Sumatra in Indonesia

Flowing lava

Mount Etna in Sicily in Italy

A lava cloud in Hawaii

Gallery

About

There are lots of different types and sizes of volcanoes, from small cracks in the Earth's surface to huge mountains which have been built up by lots of layers of lava and ash.

Magma is liquid rock in between the crust and the mantle, formed when part of the lower crust or upper mantle melts.

When magma travels up through a volcano's vent, bubbles of gas also appear. All the gas builds up pressure, which causes the magma to explode out of the volcano. When magma is thin, the gas bubbles can rise and pop easily - volcanoes located over thin magma don't have very large explosions. When magma is thick, the gas bubbles get trapped and the pressure builds up so much that the explosion shoots high up into the air. If magma cools down as it rushes up the vent, it will come out as rock or ash.

Volcanoes can be very dangerous; some of the worst natural dissters in human history have been caused by erupting volcanoes. Lava flowing out of volcanoes can burn and destroy anything in its path, and ash can be so thick in the air that it's hard to breathe. Earthquakes can happen when a volcano erupts, causing very large waves called tsunamis. If gases and ash get into the atmosphere, it can even change the weather by causing thunderstorms and cool temperatures.

When volcanoes haven't erupted for many years (perhaps thousands!), people begin to live near them in order to farm the land which is very fertile thanks to the volcanic ash. If the volcano does erupt, there can be huge loss of human life in nearby cities. In the biggest explosion in recorded history, the eruption of Tambora in Indonesia in 1815, an estimated 60,000 people lost their lives and the ash cloud affected farming, causing the worst famine of the century.

Volcanologists (scientists who study volcanoes) can sometimes tell if a volcano is going to erupt by keeping track of earthquakes underneath it. The types of gases coming out of the vent can also change close to an eruption. Animals living near a volcano may start to act differently, as if they can sense something is going to happen.

The Earth's surface is made up of lots of pieces called tectonic plates. These plates can slide against each other, which lets magma from underneath squeeze up through the cracks. When tectonic plates move, it also causes earthquakes. Most volcanoes are located along the edges of tectonic plates, especially around the Pacific Ocean - this is called the Pacific Ring of Fire.

The ancient Romans wrote about a huge volcanic eruption that happened in 79 AD in Pompeii. The ash and rocks that erupted out of Mount Vesuvius buried nearby towns and killed more than 2,000 people. Mount Vesuvius is dormant today.

Other famous volcanic eruptions in history are:

Mount Tambora (Indonesia) in 1815

Krakatoa (Indonesia) in 1883

Mount Pelée (Martinique) in 1902

Mount St Helens (Washington, USA) in 1980

Mount Pinatubo (Philippines) in 1991

Eyjafjallajokull (Iceland) in 2010

Words to know

Active volcano - a volcano that erupts regularly

Crater - the bowl-shaped area at the top of a volcano's vent

Dormant volcano - a volcano that has not erupted in a very long time, but could again

Extinct volcano - a volcano that has not erupted in thousands of years, and doesn't look like it will erupt again

Magma chamber - the pool of magma located underneath the volcano's vent

Supervolcano - a volcano that has an eruption where the amount of stuff that comes out is more than 1,000 cubic kilometres

Vent - the main part of a volcano where magma and gasses come through from deep inside the Earth

Volcanologist - a scientist who studies volcanoes

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Volcanoes are big holes that let out hot gasses, ash and magma from deep inside the Earth. Many volcanoes are mountains, made up of layers of lava and ash. Many volcanoes have several vents - a main one, and secondary ones that branch off the main vent.

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Universe Today: 10 Interesting Facts about Volcanoes

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Universe Today: 10 Interesting Facts about Volcanoes

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Want some volcano facts? Here are 10 interesting facts about volcanoes. Some of these facts you'll know, and others may surprise you. Whatever the case, volcanoes are amazing features of nature that demand our respect.

1. There are Three Major Kinds of Volcanoes:

Although volcanoes are all made from hot magma reaching the surface of the Earth and erupting, there are different kinds. Shield volcanoes have lava flows with low viscosity that flow dozens of kilometers; this makes them very wide with smoothly sloping flanks.

Stratovolcanoes are made up of different kinds of lava, and eruptions of ash and rock and grow to enormous heights. Cinder cone volcanoes are usually smaller, and come from short-lived eruptions that only make a cone about 400 meters high.

2. Volcanoes Erupt Because of Escaping Magma:

About 30 km beneath your feet is the Earth's mantle. It's a region of superhot rock that extends down to the Earth's core. This region is so hot that molten rock can squeeze out and form giant bubbles of liquid rock called magma chambers. This magma is lighter than the surrounding rock, so it rises up, finding cracks and weakness in the Earth's crust.

When it finally reaches the surface, it erupts out of the ground as lava, ash, volcanic gasses and rock. It's called magma when it's under the ground, and lava when it erupts onto the surface.

3. Volcanoes can be Active, Dormant or Extinct:

An active volcano is one that has had an eruption in historical times (in the last few thousand years). A dormant volcano is one that has erupted in historical times and has the potential to erupt again, it just hasn't erupted recently. An extinct volcano is one that scientists think probably won't erupt again. Here's more information on the active volcanoes in the world.

4. Volcanoes can Grow Quickly:

Although some volcanoes can take thousands of years to form, others can grow overnight. For example, the cinder cone volcano Paricutin appeared in a Mexican cornfield on February 20, 1943. Within a week it was 5 stories tall, and by the end of a year it had grown to more than 336 meters tall. It ended its grown in 1952, at a height of 424 meters. By geology standards, that's pretty quick.

5. There are 20 Volcanoes Erupting Right Now:

Somewhere, around the world, there are likely about 20 active volcanoes erupting as you're reading this. Some are experiencing new activity, others are ongoing. Between 50-70 volcanoes erupted last year, and 160 were active in the last decade. Geologists estimate that 1,300 erupted in the last 10,000 years.

Three quarters of all eruptions happen underneath the ocean, and most are actively erupting and no geologist knows about it at all. One of the reasons is that volcanoes occur at the mid ocean ridges, where the ocean's plates are spreading apart. If you add the underwater volcanoes, you get an estimate that there are a total of about 6,000 volcanoes that have erupted in the last 10,000 years.

6. Volcanoes are Dangerous:

But then you knew that. Some of the most deadly volcanoes include Krakatoa, which erupted in 1883, releasing a tsunami that killed 36,000 people. When Vesuvius exploded in AD 79, it buried the towns of Pompeii and Herculaneum, killing 16,000 people.

Mount Pelee, on the island of Martinique destroyed a town with 30,000 people in 1902. The most dangerous aspect of volcanoes are the deadly pyroclastic flows that blast down the side of a volcano during an eruption. These contain ash, rock and water moving hundreds of kilometers an hour, and hotter than 1,000 degrees C.

7. Supervolcanoes are Really Dangerous:

Geologists measure volcano eruptions using the Volcano Explosivity Index, which measures the amount of material released. A "small" eruption like Mount St. Helens was a 5 out of 8, releasing a cubic kilometer of material. The largest explosion on record was Toba, thought to have erupted 73,000 years ago.

It released more than 1,000 cubic kilometers of material, and created a caldera 100 km long and 30 kilometers wide. The explosion plunged the world into a world wide ice age. Toba was considered an 8 on the VEI.

8. The Tallest Volcano in the Solar System isn't on Earth:

That's right, the tallest volcano in the Solar System isn't on Earth at all, but on Mars. Olympus Mons, on Mars, is a giant shield volcano that rises to an elevation of 27 km, and it measures 550 km across. Scientists think that Olympus Mons was able to get so large because there aren't any plate tectonics on Mars. A single hotspot was able to bubble away for billions of years, building the volcano up bigger and bigger.

9. The Tallest and Biggest Volcanoes on Earth are side by side:

The tallest volcano on Earth is Hawaii's Mauna Kea, with an elevation of 4,207 meters. It's only a little bigger than the largest volcano on Earth, Mauna Loa with an elevation of only 4,169 meters. Both are shield volcanoes that rise up from the bottom of the ocean. If you could measure Mauna Kea from the base of the ocean to its peak, you'd get a true height of 10,203 meters (and that's bigger than Mount Everest).

10. The Most Distant Point from the Center of the Earth is a Volcano:

You might think that the peak of Mount Everest is the most distant point from the center of the Earth, but that's not true. Instead, it's the volcano Chimborazo in Ecuador. That's because the Earth is spinning in space and is flattened out. Points at the equator are further from the center of the Earth than the poles. And Chimborazo is very close to the Earth's equator.

We have written many articles about volcanoes for Universe Today. Here's an article that tackles about the 10 facts about earth's core. You might also want to read on the 10 facts about earth. And here's more: all about volcanoes.

Want more resources on the Earth? Here's a link to NASA's Human Spaceflight page, and here's NASA's Visible Earth.

We have also recorded an episode of Astronomy Cast about Earth, as part of our tour through the Solar System - Episode 51: Earth.

Reference:
USGS Volcano Hazards Program

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Want some volcano facts? Here are 10 interesting facts about volcanoes. Some of these facts you'll know, and others may surprise you. Whatever the case, volcanoes are amazing features of nature that demand our respect. 1. There are Three Major Kinds of Volcanoes: Although volcanoes are all made from hot magma reaching the surface of ...

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Volcano facts | National Geographic Kids

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Check out these fascinating volcano facts with National Geographic Kids! What is a volcano? Why does it erupt? And where can you find the world's biggest?

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Enjoy our awesome range of Earth facts for kids. Check out the cool trivia and have fun learning about some of our planet's most amazing features.

Fun Volcano Facts

Check out these fun volcano facts for kids. Learn about hot magma, famous eruptions, volcanoes on other planets, volcanic gases, flowing lava and more. Enjoy our wide range of strange and interesting facts about volcanoes.

Volcanoes are openings in the Earth's surface. When they are active they can let ash, gas and hot magma escape in sometimes violent and spectacular eruptions.

The word volcano originally comes from the name of the Roman god of fire, Vulcan.

Volcanoes are usually located where tectonic plates meet. This is especially true for the Pacific Ring of Fire, an area around the Pacific Ocean where over 75% of the volcanoes on Earth are found.

While most volcanoes form near tectonic boundaries, they can also form in areas that contain abnormally hot rock inside the Earth. Known as mantle plumes, these hotspots are found at a number of locations around the globe with the most notable being in Hawaii.

Hot liquid rock under the Earth's surface is known as magma, it is called lava after it comes out of a volcano.

Some famous volcanic eruptions of modern times include Mount Krakatoa in 1883, Novarupta in 1912, Mount St Helens in 1980 and Mt Pinatubo in 1991.

While we certainly have some big volcanoes here on Earth, the biggest known volcano in our solar system is actually on Mars. Its name is Olympus Mons and it measures a whooping 600km (373 miles) wide and 21km (13 miles) high.

The object with the most volcanic activity in our solar system is Io, one of Jupiter's moons. Covered in volcanoes, its surface is constantly changing to the large amount of volcanic activity.

Most people think of volcanoes as large cone shaped mountains but that is just one type, others feature wide plateaus, fissure vents (cracks were lava emerges) and bulging dome shapes.

There are also volcanoes found on the ocean floor and even under icecaps, such as those found in Iceland.

Volcanoes can be active (regular activity), dormant (recent historical activity but now quiet) or extinct (no activity in historical times and unlikely to erupt again). While these terms are useful, scientists are more likely to describe volcanoes by characteristics such a how they formed, how they erupt and what their shape is.

Common volcanic gases include water vapor, carbon dioxide, sulfur dioxide, hydrogen chloride, hydrogen fluoride and hydrogen sulfide.

Volcanic eruptions can send ash high into the air, over 30km (17 miles) above the Earth's surface.

Large volcanic eruptions can reflect radiation from the Sun and drop average temperatures on Earth by around half a degree. There have been several examples of this over the last century.

Pumice is a unique volcanic rock ( igneous) that can float in water. It can also be used as an abrasive and is sometimes used in beauty salons for removing dry skin.

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Fun Volcano Facts for Kids - Interesting Facts about Volcanoes

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Enjoy our awesome range of Earth facts for kids. Check out the cool trivia and have fun learning about some of our planet's most amazing features. Fun Volcano Facts Check out these fun volcano facts for kids. Learn about hot magma, famous eruptions, volcanoes on other planets, volcanic gases, flowing lava and more.

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List of active volcanoes includes the volcanoes which are currently erupting, or have erupted in the last 10,000 years. An example of an active volcano is Mount St. Helens in the United States (US).

Most scientists consider a volcano active if it has erupted in the holocene (historic times) period.

There are more than 1,500 volcanoes that could be active today. An estimated 500 million people live near active volcanoes.

Select list

There are active volcanoes in every part of the world. There are about 1,500 active volcanoes, many in the region of the Pacific Ocean.

Pacific rim

The Pacific rim's " Ring of Fire" is an arc around the Pacific Ocean where there are 400+ volcanoes.

This list is not finished; you can help Wikipedia by adding to it.

Chimborazo in Ecuador

Haleakala in US (Hawai'i)

Kilauea in the US (Hawaii)

Mount Adams in US (Washington)

Mount Mayon in Albay in the Philippines

Mount Olympus in US (Washington)

Mount Slamet in Central Java, Indonesia

Mount St Helens in US Washington

Mauna Kea in US (Hawai'i)

Mauna Hualalai in US (Hawai`i)

Other regions

Other regions of active volcanoes include the Mediterranean Sea, the Atlantic Ocean and other places.

This list is not finished; you can help Wikipedia by adding to it.

Related pages

References

1. The plural of volcano can be either volcanos or volcanoes. Both are equally correct, and it is not a matter of British vs US spelling. Oxford English Dictionary. Spelling in any particular Simple page tries to be consistent.

2. Ball, Jessica. "Voices: Dead or alive ... or neither? Why a dormant volcano is not a dead one," Earth Magazine (American Geosciences Institute). September 8, 2010. Retrieved 2012-6-14.

3. Malahoff, Alexander. "Loihi Submarine Volcano: A unique, natural extremophile laboratory," National Oceanic and Atmospheric Administration (NOAA), December 18, 2000. Retrieved 2012-6-15. Archived 9 April 2012 at WebCite

4. USGS, "Mount Baker-Living with an Active Volcano," May 25, 2005. Retrieved 2012-6-15. Archived 7 May 2011 at WebCite

5. "Villagers flee biggest Mt Merapi eruption yet," The Guardian (UK). June 8, 2006. Retrieved 2012-6-15.

6. UNESCO, "Heard and McDonald Islands"; Australian government, "Heard Island and McDonald Islands, Landforms". Retrieved 2012-6-15.

7. "'Ladies and gentlemen, on your left you will see an erupting volcano': The stunning sight Caribbean holidaymakers saw from plane," Daily Mail (UK). 1 April 2010. Retrieved 2012-6-14.

en:Volcano#Active

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List of active volcanoes includes the volcanoes which are currently erupting, or have erupted in the last 10,000 years. An example of an active volcano is Mount St. Helens in the United States (US). Most scientists consider a volcano active if it has erupted in the holocene (historic times) period.

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A volcano is a mountain where lava (hot, liquid rock) comes from a magma chamber under the ground.

Most volcanoes have a volcanic crater at the top. When a volcano is active, materials come out of it. The materials include lava, steam, gaseous sulfur compounds, ash and broken rock pieces.

When there is enough pressure, it causes the volcano to erupt. The pressure blows off the top of the volcano. The magma comes out, sometimes quickly and sometimes slowly.

Volcanoes are found on planets other than Earth. An example is Olympus Mons on Mars.

Types of volcanoes

The lava and pyroclastic material that comes out from volcanoes can make many different kinds of land shapes. There are two basic kinds of volcanoes.

Shield volcanoes

These volcanoes are formed by low-silica (i.e. basic) lava.

Shield volcanoes are built out of layers of lava from continual eruptions (without explosions). Because the lava is so fluid, it spreads out, often over a wide area. Shield volcanoes do not grow to a great height, and the layers of lava spread out to give the volcano gently sloping sides. Shield volcanoes can produce huge areas of basalt, which is usually what lava is when cooled.

The base of the volcano increases in size over successive eruptions where solidified lava spreads out and accumulates. Some of the world's largest volcanoes are shield volcanoes.

Even though their sides are not very steep, shield volcanoes can be huge. Mauna Kea in Hawaii is the biggest mountain on Earth if it is measured from its base on the floor of the sea.

Stratovolcanoes

A stratovolcano, also known as a composite volcano, is a tall, conical volcano. It is built up of many layers of hardened lava, tephra, pumice, and volcanic ash.

Unlike shield volcanoes, stratovolcanoes have a steep profile and periodic eruptions. The lava that flows from stratovolcanoes cools and hardens before spreading far. It is sticky, that is, it has high viscosity. The magma forming this lava is often felsic, with high-to-intermediate levels of silica, and less mafic magma. Big felsic lava flows are uncommon, but have travelled as far as 15 km (9.3 mi).

Two famous stratovolcanoes are Japan's Mount Fuji, and Vesuvius. Both have big bases and steep sides that get steeper and steeper as it goes near the top. Vesuvius is famous for its destruction of the towns Pompeii and Herculaneum in 79 AD, killing thousands.

A caldera is a basin-like feature formed by collapse of land after a volcanic eruption. This happens after a huge stratovolcano blows its top off. The base of the crater then sinks, leaving a caldera where the top of the volcano was before. Krakatoa, best known for its catastrophic eruption in 1883, is much smaller now.

How volcanoes are formed

There are two main processes.

Volcanoes are made when two tectonic plates come together. When these two plates meet, one of them (usually the oceanic plate) goes under the continental plate. This is the process of subduction. Afterwards, it melts and makes magma (inside the magma chamber), and the pressure builds up until the magma bursts through the Earth's crust.

The second way is when a tectonic plate moves over a hot spot in the Earth's crust. The hot spot works its way through the crust until it breaks through. The caldera of Yellowstone Park was formed in that way; so were the Hawaiian Islands.

Classification

A traditional way to classify or identify volcanoes is by its pattern of eruptions. Those volcanoes which may erupt again at any time are called active. Those that are now quiet called dormant (inactive). Those volcanos which have not erupted in historical times are called extinct.

An active volcano is currently erupting, or it has erupted in the last 10,000 years. An example of an active volcano is Mount St. Helens in the United States (US).

A dormant volcano is "sleeping," but it could awaken in the future. Mount Rainier in the United States is considered dormant.

An extinct volcano has not erupted in the past 10,000 years. Edinburgh Castle in Scotland is located atop an extinct volcano.

Some volcanoes

Largest volcano on Earth

The Earth's largest volcano has been discovered. It is 2km below the sea on an underwater plateau known as the Shatsky Rise. This is about 1,600km east of Japan. The previous record-holder, Mauna Loa in Hawaii, is still the largest volcano on land.

The 310,000 sq km (119,000 sq mi) volcano, Tamu Massif, is comparable in size to Mars' vast Olympus Mons volcano, which is the largest in the Solar System. It was formed about 145 million years ago when massive lava flows erupted from the centre of the volcano to form a broad, shield-like feature. That suggests the volcano produced a flood basalt eruption.

The Tamu Massif extends some 30 km (18 miles) into the Earth's crust. The researchers doubted the submerged volcano's peak ever rose above sea level during its lifetime and say it is unlikely to erupt again.

"The bottom line is that we think that Tamu Massif was built in a short (geologically speaking) time of one to several million years and it has been extinct since," co-author William Sager, of the University of Houston told the AFP news agency.

"There were lots of oceanic plateaus (that) erupted during the Cretaceous period (145-65 million years ago) but we don't see them since. Scientists would like to know why... The biggest oceanic plateau is Ontong Java plateau, near the equator in the Pacific, east of the Solomon Islands. It is much bigger than Tamu - it's the size of France".

Related pages

References

Other websites

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A volcano is a mountain where lava (hot, liquid rock) comes from a magma chamber under the ground. Most volcanoes have a volcanic crater at the top. When a volcano is active, materials come out of it. The materials include lava, steam, gaseous sulfur compounds, ash and broken rock pieces.

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Mount Vesuvius, on the west coast of Italy, is the only active volcano on mainland Europe. It is best known because of the eruption in A.D. 79 that destroyed the cities of Pompeii and Herculaneum, but Vesuvius has erupted more than 50 times.

Mount Vesuvius facts

Vesuvius in 2013 was 4,203 feet (1,281 meters) tall. After each eruption, the size of the cone changes, according to Encyclopedia Britannica. The volcano also has a semicircular ridge called Mount Somma that rises to 3,714 feet (1,132 m). The valley between the cone and Mount Somma is called Valle del Gigante or Giant's Valley.

Mount Vesuvius is considered to be one of the most dangerous volcanoes in the world because of its proximity to the city of Naples and the surrounding towns on the nearby slopes.

The volcano is classed as a complex stratovolcano because its eruptions typically involve explosive eruptions as well as pyroclastic flows. A pyroclastic flow is a high-density mix of hot lava blocks, pumice, ash and volcanic gas, according to the U.S. Geological Survey. Vesuvius and other Italian volcanoes, such as Campi Flegrei and Stromboli, are part of the Campanian volcanic arc. The Campanian arc sits on a tectonic boundary where the African plate is being subducted beneath the Eurasian plate.

Under Vesuvius, scientists have detected a tear in the African plate. This "slab window" allows heat from the Earth's mantle layer to melt the rock of the African plate building up pressure that causes violent explosive eruptions. In the past, Mount Vesuvius has had a roughly 20-year eruption cycle, but the last serious eruption was in 1944.

Pompeii

Mount Vesuvius destroyed the city of Pompeii, a city south of Rome, in A.D. 79 in about 25 hours, according to History. Because the city was buried so quickly by volcanic ash, the site is a well-preserved snapshot of life in a Roman city. There is also a detailed account of the disaster recorded by Pliny the Younger, who interviewed survivors and recorded events in a letter to his friend Tacitus. [ Related: Pompeii 'Wall Posts' Reveal Ancient Social Networks]

(Image credit: deepblue-photographer Shutterstock)

Pompeii was established in 600 B.C. and was slowly recovering from a major earthquake that rocked the city in February of A.D. 62. The shallow quake, originating beneath Mount Vesuvius, had caused major damage to the springs and piping that provided the city's water. Reconstruction was being carried out on several temples and public buildings. Seneca, a historian, recorded that the quakes lasted for several days and also heavily damaged the town of Herculaneum and did minor damage to the city of Naples before subsiding. The major quake was followed by several minor shakes throughout the following years. [ Image Gallery: Pompeii's Toilets]

Because seismic activity was so common in the area, citizens paid little attention in early August of 79 when several quakes shook the earth beneath Herculaneum and Pompeii. People were unprepared for the explosion that took place shortly after noon on the 24th of August. Around 2,000 residents survived the first blast.

(Image credit: Alessandro Colle Shutterstock)

Pliny the Elder, a Roman author, described the massive debris cloud. "It resembled a (Mediterranean) pine more than any other tree. Like a very high tree the cloud went high and expanded in different branches ... sometimes white, sometimes dark and stained by the sustained sand and ashes." In Pompeii, ash blocked the sun by 1 p.m. and the people tried to clear heavy ash from rooftops as it fell at a rate of about 6 inches (15 centimeters) an hour. [ Image Gallery: Preserved Pompeii - Photos Reveal City in Ash]

Shortly after midnight, a wall of volcanic mud engulfed the town of Herculaneum, obliterating the town as its citizens fled toward Pompeii. About 6:30 a.m. on the following morning, a glowing cloud of volcanic gases and debris rolled down Vesuvius' slopes and enveloped the city of Pompeii. Most victims died instantly as the superheated air burned their lungs and contracted their muscles, leaving the bodies in a semi-curled position to be quickly buried in ash and thus preserved in detail for hundreds of years.

Far away in Misenum, approximately 13 miles (21 kilometers) from Pompeii, Pliny the Younger, the 18-year-old nephew of Pliny the Elder, and his mother joined other refugees escaping the earthquakes rocking their city. They observed, "the sea retreating as if pushed by the earthquakes." This was probably caused by a tsunami at the climax of the eruption, which gives us the time frame for historical record. Pliny writes of "black and horrible clouds, broken by sinuous shapes of flaming wind." He describes people wheezing and gasping because of that wind; the same wind that doomed the people of Pompeii.

It is believed that around 30,000 people died from the eruption of Vesuvius in 79.

WWII eruption

On March 17, 1944, a two-week-long eruption began with lava from the summit of Mount Vesuvius. In an article by Life Magazine, Giuseppe Imbo, director of the Mt. Vesuvius Observatory, is quoted as saying, "A marvelous thing, my Vesuvius. It covers land with precious ash that makes the earth fertile and grapes grow, and wine. That's why, after every eruption, people rebuild their homes on the slopes of the volcano. That is why they call the slopes of Vesuvius the compania felix - the happy land."

During the eruption, soldiers and airmen of the 340th Bomber Group were stationed at the Pompeii Airfield just a few miles from the base of the volcano. Diaries record the awesome sights and sounds they witnessed in this latest major eruption. Guards wore leather jackets and "steel pot" helmets to protect themselves from rains of hot ash and small rocks. Tents collapsed or caught fire when hot cinders were blown over them.

Sgt. Robert F. McRae wrote in his diary on March 20, 1944, according to the American Geosciences Institute, "As I sit in my tent ... I can hear at four- to 10-second intervals the loud rumbling of the volcano on the third day of its present eruption. The noise is like that of bowling balls slapping into the pins on a giant bowling alley. To look above the mountain tonight, one would think that the world was on fire. The thickly clouded sky glows like that above a huge forest fire. Glowing brighter as new spouts of flame and lava are spewn from the crater. As the clouds pass from across the top of the mountain, the flame and lava can be seen shooting high into the sky to spill over the sides and run in red streams down the slopes. ... Today it is estimated that a path of molten lava 1 mile long, half a mile wide, and 8 feet deep is rolling down the mountain. Towns on the slopes are preparing to evacuate. Our location is, apparently, safe. At any rate no one here, civilian or Army authorities, seems too much worried. Lava has not started to flow down this side of the mountain as yet but is flowing on the other side toward Naples."

On March 22, they were forced to evacuate, leaving behind 88 Allied aircraft. After the volcano subsided, they returned on the 30th to find the planes were a total loss. Engines were clogged by ash, control panels were useless tangles of fused wire, canopies had holes from flying rock or were etched to opacity by wind driven ash.

One airman of the 489th Bomber Squadron complained in his diary when Axis Sally broadcast a radio show dedicated to the "survivors" of the Vesuvius eruption (actually the most severe human casualty was a wrist sprained during the evacuation). She told all of Europe that "Colonel Vesuvius" had destroyed all of them. The diarist was justifiably proud of the work he did with his fellows in recovery. By April 15, the planes had been replaced and the 340th Bomber Group was back to full strength and ready to fly missions from their new base.

Though no soldiers were killed, 26 Italian civilians died and nearly 12,000 were displaced by the 1944 eruption, according to the American Geosciences Institute.

Current status

Since 1944, there have been hundreds of minor earthquakes in the region around Mount Vesuvius. The most serious earthquake rocked Naples in October 1999. The magnitude-3.6 quake was felt as far as 15 miles (24 km) from the base of the volcano and was of the same magnitude as a quake that occurred 17 years prior to the last truly major explosion that devastated Naples in 1631.

In 2016, excavations on the outskirts of Pompeii revealed more victims of the volcanic eruption. Archaeologists discovered the remains of four people, including one teenage girl, in the ruins of a shop, according to a statement from the Soprintendenza Pompei, the Italian authority in charge of managing the ancient site.
Additional reporting by Alina Bradford, Live Science contributor Additional resources

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Mount Vesuvius & Pompeii: Facts & History

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Mount Vesuvius, on the west coast of Italy, is the only active volcano on mainland Europe. It is best known because of the eruption in A.D. 79 that destroyed the cities of Pompeii and Herculaneum, but Vesuvius has erupted more than 50 times. Vesuvius in 2013 was 4,203 feet (1,281 meters) tall.