The concept “climate” refers to the predominant or average weather recorded in a given area for a time long enough that all the possible weather scenarios in such area may happen. The climate is a permanent or long-time concept while the weather changes within hours. Therefore, “climate” and “weather” are different but related concepts.

The climate depends on several interrelated factors: latitude, longitude, elevation, topography, proximity to the sea and wind direction. Therefore, although the areas located near the equator are usually warm, there are mountain zones on the same latitude that are cold.

In general, there are three types of climate: warm, temperate, and polar.

Multiple Types of Climates.

In general, there are three types of climate: warm, temperate, and polar. Warm climates are found at low latitudes and are characterized by high temperatures; the inclination of sunlight is minimal. Therefore, the radiation is constant. In temperate climates, located at mid-latitudes, temperatures are usually mild to moderate, and polar climates, which occur at high latitudes, usually have temperatures below 10 °C during the warmer months; typically they are found in the polar circles.
Now these three groups have more precise climates, so it is important to know the classifications.

Climate classification.

Although there are several classifications of climate, the best known is perhaps the one made by Wladimir Köppen, a German climatologist of Russian origin who created this climate classification:

Group A: Tropical climate.

Tropical climate

a. Tropical wet.
It is a warm climate but with regular rain: the annual rainfall exceeds 150 centimeters. Temperatures vary little throughout the year.

b. Tropical wet and dry.
It is also known as tropical savannah. In this case, temperatures vary moderately, but they are usually warm to hot.

Group B: Dry climate.

Dry climate.

a. Arid.
Summers are hot, and winters are cool or warm. Rainfall is low.

b. Semiarid.
Although it is a hot climate, it is more moderate than the arid climate. Regions with this climate fall between those with an arid climate and tropical climates.

Group C: Moderate climate.

Moderate climate.

a. Mediterranean.
It is warm to hot climate. While winters are rainy, summers are dry.

b. Humid Subtropical.
Regions with this climate are usually in the eastern part of the continents. They experience hot, humid summers and colder winters. Precipitations have a regular distribution throughout the year, but hurricanes are common.

c. Marine West Coast.
They are in the western areas of the continents where the wind direction is from the sea to land. Winters range from cold to temperate, and summers are warm, with moderate rainfall most of the year. Examples of cities with this climate: Seattle, USA and Wellington, New Zealand.

Group D: Continental climate.

Continental climate.

a. Humid Continental.
Regions with this climate have moderate to hot summers and cold winters. Throughout the year, the temperature difference can range from – 3°C to 22°C. Most of Eastern Europe has a humid continental climate.

b. Subarctic.
An area with this climate has cool summers and cold winters. Most of the rainfall occurs during the summer. This climate is present in northern Scandinavia and Siberia.

Group E: Polar Climate.

Polar climate.
Low temperatures are the rule throughout the year, although there are variations.

a. Tundra.
This climate is dry, and permafrost, a layer of ice, regularly covers the soil. It locates in the northern limits of North America, parts of Russia, and of course, the edges of Antarctica.

b. Ice cap.
It is the coldest weather on Earth, with temperatures that are rarely below freezing point. It is present in Greenland and most of the Antarctic continent.

Group H: Highland climate.

Highland climate.
Sometimes, this climate is included in the above group (E), but other authors consider it as an individual climate (H).

It is present at very high altitudes in mountainous terrain. Areas with this climate experience rapid elevation changes, causing rapid climate changes over short distances.

Quick Facts.
The driest desert in the world is the Atacama Desert in Chile. Its average annual rainfall is 0.51 millimeters.

Volcano Eruption

What Is A Volcanic Eruption?


A volcanic eruption is one of the most dangerous and magnificent natural disasters.  When a volcano erupts, the volcano sends out ash clouds, lava and even volcanic bombs.  There is a high risk of danger from slow moving lava; though, the lava might move slowly, it is very dangerous and can cause a lot of damage to property and human life.

Volcanic eruptions comprise of 3 stages:

  • Magmatic eruptions – when gas is released under decompression.
  • Phreatomagmatic eruptions – when a thermal contraction comes from water.
  • Phreatic eruptions – when steam erupts.

The Magnitude of Volcanoes

When there is an earthquake, little vents are created in which magma is allowed to form.  This is pushed up through these vents and towards the crust of the volcano.  Steam vents are created when the magma reaches a certain level and reaches a boiling point which begins the eruption.  The eruption might result in a total eruption.  This is when gas driven explosion send magma to the volcano’s crust creating lava outpouring from the volcano.

Some eruptions are not as strong as others.  All volcanic eruptions can vary in strength; with some not reaching any civilians or causing too much damage.  However, others can spread over a vast area, sometimes reaching several miles from the volcano.  Some eruptions do not always contain lava flow or lava fountains which aren’t always very dangerous.  However, some eruptions can be on a huge scale, very violent and very, very dangerous with explosions heard from the volcano.

Some eruptions can be passive and not very dangerous however; some are explosive and can be very and high dangerous.  Some volcanoes do not just erupt from their peeks, some can have eruptions at any part of the mountain, it’s not just the peeks that are the most deadly for volcano eruptions.  One of the biggest and well known eruptions was in Pompeii.

The entire city of Pompeii was buried when the volcano at Pompeii erupted.  However, this is only one example of a type of eruption; another type of eruption is in Norway, a volcano that had been dormant for years suddenly became active, however, the local towns were evacuated and the volcano erupted. However, there was no great scale eruption.  Lava flowed but didn’t reach the town, this was a very small eruption compared to many others.

When Can An Eruption Happen?

Volcanic eruptions happen deep down inside the earth.  When the earth’s tectonic plate’s shift, it causes more than just earthquakes, it can create new volcanoes or vents.  Underneath the surface of the earth, debris, gases from the planet and molten rock are stored creating new formations of vents and volcanoes.

As soon as the magma thickens and builds up with the gases of planet can create explosions and cause lava to flow upwards and have ash released into the air causing thick clouds of smoke often seen overhead volcanoes. If there is an increased magma but a decrease of planet gases, then the eruption will not be as great.

However, lava can reach an amazing heat possibly even 2000 degrees Fahrenheit; sometimes it can be even higher than that.  Lava can actually destroy everything in its path, even an entire village.  There can be huge rocks or even boulder types reigning down from the volcano and onto populated areas.  There can also be toxic gases and ash which causes severe lung problems to many vulnerable people including children and elderly people.

Volcano eruptions can happen at any given time.  If there is a change to the tectonic plates in which a volcano sits on, then it can erupt at any given time.  There is no set time as to when they will erupt or how much damage they’ll cause.

Volcano eruption facts
Anak Krakatau Volcano erupting

Understanding the Volcanoes

When there is a volcanic eruption, there could be many other dangers which occur.  These things can be such as flash floods, mudflows, landslides and rock falls, and even earthquakes. However, there can also be things such as fire and acid rain that follows a volcano erupting.  It might not seem as though there are many active volcanoes erupting but there is a great deal of active volcanoes and the fact that they haven’t erupted doesn’t mean it will always be like this.  There are dangers every day from active volcanoes.

What Can You Do Before A Volcanic Eruption?

There are steps which anyone can take before a volcano erupts and they are very simple steps.  These small but simple steps can help protect homes, and protect your families also in the event of a volcanic eruption.  If you live in an area which has an active volcano, even if it might be up to 100 miles away, there is still a risk because a volcano can erupt at any time.

  • Have An Emergency Supply Kit

This can be a small but important kit of some of the simplest items such as water, and non perishable foods.  You should look to add batteries, radios, battery powered or hand cranked radios.  You can also have torches or flashlights just in case of a power cut or blackout; and have a first aid kit should anyone get hurt.

All of these supplies should be kept in a location which is easy to reach such as a car just in case you need to be evacuated or are being told to do so.  If possible, try to add breathing masks or goggles to see through thick ash clouds.

  • Emergency Plan

A disaster such as a volcano erupting can happen at any given time and it does mean your family mightn’t be at home when it happens.  This is why you do need to think about getting in contact with other family members and meeting up again.  You need to think carefully about all eventualities and have a good plan to get the family reunited once again.

These are simple plans but if you do live in an area very close to an active volcano, they could end up saving your life and your family’s.

You might not realize or understand that a volcano is active or is about to erupt either, however, when a volcanic eruption occurs, you have to be vigilant.  You have to be aware of what could happen and how a volcano works.

The World’s Natural Disaster

When an eruption occurs, lava can spill over and can absolutely cause mass devastation.  Even if the volcano isn’t moving fast towards the local town or village, there are still many dangers that can cause harm.  The ash clouds can be very dangerous to a person, as is the poison gases and flying debris and rocks.  There are many dangers to volcanic eruptions, though this is a natural disaster that cannot be tamed or predicted.

It might sound as though volcanoes aren’t that dangerous if they haven’t been active for years but they’re still dangerous.  They have intense heat from lava flows and of course the acid rain can all become dangerous.


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By definition, a blizzard is an extended, severe snowstorm. In order to qualify as a blizzard, winds have to be at least 35mph and rage for a longer period of time—at least three hours or more. The amount of snowfall has little to do with a storm qualifying as a snowstorm, but rather the intensity of the wind and length of time. There are two other classifications for blizzards:

–Severe blizzard: winds over 45mph, temperatures at 10 Fahrenheit or lower, near zero visibility.

–Ground blizzard: no falling snow, snow from the ground is blown by the strong winds.

A nor’easter gets it’s name from the direction of the oncoming winds. This occurs on the Atlantic side of Canada and East Coast of the USA. These storms can start as far south as the Gulf of Mexico or the North Atlantic Ocean. However, the most common usage of the name is in the coastal regions of Atlantic Canada and New England. These storms are similar to a hurricane. One of the deadliest blizzards in the USA—the Great Blizzard of 1888—was a nor’easter, killing 400 people after dumping 40-50 inches of snow.

What causes blizzards?

Blizzards are usually formed when the jet stream pitches very far south. This allows the cold air that comes from the north to collide with warm air coming from the south. This creates a strong storm system, usually developing on the northwest side of such storm systems.

Any area which is mostly flat is susceptible to blizzards, though there are some areas in the US, Australia, and the UK that suffer from blizzards more than others. However, the deadliest blizzard in recorded history occurred in Iran in 1972.

Dangers of blizzards

Blizzards are one of nature’s deadlier storms, as the conditions make travel and movement hazardous. Snowstorms disrupt traffic, but blizzards make any kind of travel nearly impossible. Almost every blizzard results in at least a few deaths, with some of the bigger ones resulting in hundreds of people dying.

Visibility is drastically reduced, in some cases to as little as 3 meters or what is called zero visibility.  In a ground blizzard, though no new snow is falling, the snow already on the ground is whipped up and around by the winds to where visibility is also close to zero.

Travel under these conditions is close to impossible. Cars have to come to a complete standstill as they can drive off the road. Because blizzards rage for so long, people can get trapped in their cars, freezing to death as they wait for it to clear. Once the storm is over, cars are often buried under mounds of snow, making it difficult for rescue teams to find them. Hypothermia sets in as people trapped outdoors try to find shelter and warmth.

Blizzards have been known to come suddenly and while it is possible to be warned in advance, it’s not always possible to be entirely prepared for the intensity of the blizzard. Clearing roads is not possible until after the blizzard has passed and then takes a long time due to the intensity of the build up. The aftermath of the blizzard can be almost as dangerous as the storm itself, as people trapped inside vehicles, unheated buildings, or outdoors take longer to be found and brought to warmth and safety.

blizzard facts and information
Snow covered car

History of blizzards

Though not as common as snowstorms, tornadoes, or even hurricanes, blizzards are deadly every time they hit. Not all blizzards are mentioned here, not even all of the most severe. This is just a sample of the havoc that blizzards can wreak.

–The white winter of 1880-1881 is one of the earliest blizzards mentioned in history books. This is considered the worst winter in US history. Because the first blizzard hit in October, before most farmers had the opportunity to bring in their crops. One after the other the blizzards continued to hit, making travel impossible, even by train. People were at the brink of starvation and train services stopped completely by January 1880 as no matter how often they cleared the tracks, another storm would come and cover them again. The snow never thawed and on February 2, 1881 a nine day blizzard hit again. By then, towns and farmers had to tunnel through the snow to get to livestock, wood for heating, and supplies.  Once the snow started melting, huge areas were flooded, washing away huge areas around the Missouri river. The town of Yankton, currently South Dakota, was nearly completely washed away by the overflowing river.

–The Iran Blizzard of 1972 is the deadliest recorded blizzard. Starting on February 3, until February 9, more than 10 feet of snow fell, the worst areas in Southern Iran getting up to 26 feet of snow. Whole villages died, one being completely buried beneath the snow. Approximately 4000 people died.

–The Armistice Day Blizzard in 1947 came somewhat unexpected, resulting in a lot of deaths. On the morning of the blizzard, the weather was warm, resulting in many hunters going out to take advantage of ideal conditions. Within a few hours, the blizzard hit, raging through the night and into the next day. 145 deaths were reported as a result of the 1,000 mile wide storm. Many hunters were not dressed warmly enough to withstand the wind and snow. Many were stranded on islands in the Mississippi, or drowned trying to get back to land.

–The Schoolhouse Blizzard in 1888 is different from the nor’easter and in some ways more heart breaking. Because the day started out relatively fair, people went about their lives, with children going to school and adults going to work. The storm hit early in the day, leaving thousands stranded; mostly children in their one-room schoolhouses. 235 people died; including children.

Although meteorologists are now able to more accurately predict blizzards, the storms still have the ability to cripple whole cities at a time, and deaths are almost always inevitable. Over the years, rescue missions during and after blizzards are becoming better and preparedness goes a long way towards preventing large amounts of casualties. It has also become considerably easier to notify people of oncoming storms, with more reliable predictions and getting the word out quickly and effectively.

Countries which are not used to large amounts of snow, extreme cold, and long periods of strong winds tend to have a harder time coping when the storms hit. Regardless of where the blizzards hit, there is never a way to be completely prepared. There is always a chance of power outages, communications systems breaking down, people going for long periods with little or no heat, and getting trapped outdoors or in a vehicle. During winter months, people are advised to pay close attention to weather warning coming over the radio or TV. There are weather websites set up to help people prepare for blizzards and post warnings when a snowstorm is being upgraded to a blizzard.


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Submarine Volcano


A submarine volcano is different than all of the other types because they are found underwater. These volcanoes are in fact some of the most productive of the volcanic systems, producing around three quarters of the year’s output of magma but most people do not think of them because they are usually located around 8,500 feet underwater on average. Some scientists estimate that in the Pacific Ocean in just a million square kilometers of the ocean floor you will find around 4,000 volcanoes. Like other types, a submarine volcano can vary greatly in height, although it is estimated that around 75,000 of those in the Pacific Ocean rise half a mile over the ocean floor.


Although each submarine volcano is located underwater, it will still produce eruptions while active and the products of these eruptions are what shape the way the sea floor looks. Scientists estimate that out of the million or so of these volcanoes that can be found around the world, many thousands of them are active. Despite this because of their location underwater, it can be hard to catch a submarine volcano in the eruption process. However, scientists do know that most eruptions from these volcanoes will take place in shallow water although recent technological advances have helped scientists document those that take place in deeper water well.


Because a submarine volcano is located underwater, the deposits that are created during the eruption can be very different than those of other types of volcanoes. Volcanologists are actually unsure if an explosive eruption of a submarine volcano is even possible. That is because due to the high pressure created by the water (250 times the atmospheric pressure) bubbles are hard to form in the magma and lava. Because the water will almost instantly quench the lava, the outer surface of volcanic flows becomes glass.

Lava Flows

The shape of the flows of a submarine volcano tends to be pillow-like as compared to the blocky flows that are typical of land volcanoes. These pillows are created when the crust of a flow will split causing the lava to ooze out at which point it flows a very short distance and solidifies. The process then repeats with the new piece of lava and ends up creating what seems to be a large stack of pillows. The lava flows can also take other shapes, such as sheet flows and tumuli, which is an inflation feature.

Volcanic Ecosystems

Like all volcanoes, a submarine volcano is associated with a unique volcanic ecosystem. These are usually located by hydrothermal vents, or black smokers, which have been located at all of the mid-ocean ridges around the world. At these vents, hydrogen sulfide and water in addition to other minerals exit these vents, creating an ecosystem of organisms that live using sulfur instead of sunlight. Here you can find tube worms, mussels, giant clams and other organisms.

Detection Of Eruptions

As mentioned earlier, despite recent advances in technology it is still difficult for scientists to detect the eruption of a submarine volcano. In fact, they have only been capable of detecting them at all since around the year 1990. Long before they were first detected, oceanographers and volcanologists alike were aware that submarine volcano eruptions were occurring but had no way to know where and when. In recent decades, however, they created a new system that measures the small earthquakes that are normally part of magma migration.

Instead of relying on feeling vibrations like they do with earthquakes on land, this system listens for them as the vibrations underwater will produce an acoustic wave. Since this system was created, it has been much easier for scientists to pinpoint the location of these underwater eruptions.


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