Earthquakes are collisions and vibrations that can happen in the earth. Earthquakes happen when two plates slide past each other. The plates are very rough and as they slide against each other, the edges can sometimes get caught. The plates continue to move away, but are still captured at what is called the fault line (where the two plates are caught). After a while, the force pulling the plates becomes stronger than the friction holding them together, and they are forcefully detached. This creates vibrations which travel through the earth. Earthquakes can also happen when plates crash against each other.

Drawn by Me

Shock Waves: Waves of vibrations which travel through the earth.
Focus: Origin of the earthquake vibrations.
Epicenter: The surface point right above the focus.

Seismograph

There are two things to measure in earthquakes, there is the magnitude and intensity. The magnitude is the energy released, no matter how strong or weak the vibrations can be in certain areas affected. To measure the magnitude, we use a seismograph.

Building Destruction

The measuring unit is called a Richter Scale. A seismograph looks like a needle on top of a long sheet of paper. The needle wobbles and creates lines on the rotating paper. In a Richter Scale, 1 is a very, very weak earthquake, so weak that it may not even be felt. As you go up through the digits, the magnitude increases. From 3.5 onward the earthquake is felt. The biggest earthquake ever recorded with the Richter Scale was 9.5 in Chile on May 22, 1960.

The intensity is the strength of the vibrations. These vary from area to area touched by an earthquake. Intensity is measured by the damage and effect an earthquake had on people, buildings, and the natural environment.
Earthquakes can cause a lot of damage if strong enough. Pipes can burst, roads can crack and break, some buildings can wobble, sway and break.

References:
http://earthquake.usgs.gov/learn/kids/
http://science.howstuffworks.com/earthquake6.htm
http://earthquake.usgs.gov/learn/topics/mag_vs_int.php
http://www.sizes.com/natural/quakintens.htm
http://www.etest.ie/subjects/-geography/new-complete-geography-4th-edition
http://bit.ly/d7rZLq
http://q2projectearthquakes.blogspot.com/2008/11/earthquakes.html

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Did You Know? There are different types of volcanic eruptions, one of which is a Plinian eruption. It is named after Pliny the Younger, a young man who survived the attack of Mount Vesuvius in 79 AD, and later described the event, although no one believed him at the time. A Plinian eruption consists firstly of a huge vertical column of gas and ash, and a rain of hardened drops of lava which fall from the ash and gas clouds dispersed above. Sometimes, the immense amount of magma being erupted can break off the summit of the volcano, creating what is called a caldera (sort of avalanche).  A much more recent example of a Plinian eruption is in 2010, the Mount Eyjafjallajökull in Iceland. The ash and gas clouds dispersed in the atmosphere by the volcano caused an almost worldwide aerial disruption for a small week. I myself was ‘stuck’ in France because of this Plinian eruption.

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Volcanoes are like mountains made of cooled down lava. They are formed because plates, which make up the earth’s crust, move around like sponges on water. Some bang into each other while others move away from each other. They float on what is called the Mantle. This is a lot of molten rock just being boiled, churned, and moved around by the very, very hot core of the earth. This molten rock is called magma.

When  the plates move away from each other, gaps are created in between them. When plates bang into each other, sometimes the force of it causes one of the plates to slide over one another. Eventually, one plate gets dipped into the mantle, which is hot enough to melt the plate in more magma. This surplus must be evacuated and the magma is pushed out through the nearest gap created.

Once magma leaves the mantle, it is called lava. Lava spurts out, and eventually cools down, forming a ridge and small slopes on the ground. A next eruption forms a new layer of rock and the next eruption does the same. After a very long time and numerous eruptions, a volcano is clearly visible. It may take some time for a volcano to erupt, meaning as soon as there is a surplus of magma, it is not directly pushed out. There is a ‘chamber’ where the magma builds up, and when it is full, then the volcano can eject the lava. While the magma builds up, a volcano is said to be dormant, from the Latin ‘to sleep’. If no more magma builds up, the volcano is extinct. If the volcano is erupting or there is not much time in between eruptions, it is active.

Crater of Mount Aso

I myself have seen two volcanos. I saw Mount Fuji (Japan) from the window in a train passing by it, and I also visited Mount Aso (Japan). I took a cable car to the top of the volcano, to the summit. There were shelters build all around it in case of a spontaneous eruption (It is an active volcano). It is one of the largest in the world too. I definitely recommend seeing at least one volcano in your lifetime.

References: http://www.heronsgate.milton-keynes.sch.uk/projects/volcano2/formation.html, http://en.wikipedia.org/wiki/Volcano, http://en.wikipedia.org/wiki/Mount_Aso,

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Clouds are great big visible masses of tiny water droplets or ice crystals. There are four major groups of clouds: High Clouds, Middle Clouds, Low Clouds, Vertical Clouds.

High clouds: These will form between 3,000 and 8,000 m (10,000 and 25,000 ft) in the polar regions. They will form at 5,000 and 12,000 m (16,500 and 40,000 ft) in the temperate regions. They will form at 6,000 and 18,000 m (20,000 and 60,000 ft) in the tropical regions. There are three different types of high clouds:

Cirrocumulus

-Cirrocumulus (Cc): the term cirrocumulus actually refers to one cloud, but it is typically used to refer to an entire blanket of cirrocumulus. The single unit is referred to as a ‘cloudlet’. These appear as large, white patches or tufts without a gray shadow. One ‘cloudlet’ usually appears no larger than a finger held at arms length.

Cirrus

-Cirrus (Ci): a cirrus cloud is easily recognisable by its appearance. It is thin, wisp like, kind of looking like long thin strands of hair. The wind is very strong and the strands of cloud often take on the shape of wind’s direction.

Cirrostratus

-Cirrostratus (Cs): these are thin, very hard to recognise clouds. They usually form halos around the sun, and when they do appear visibly, they are whitish in colour, without any other distinguishing features.

Middle Clouds: middle clouds form at 2,000 m (6,500 ft) but can form at up to 8,000 m (25,000 ft) depending on the region. Nimbostratus clouds are sometimes included with the middle clouds but are officially a part of the low clouds.

Altostratus

-Altostratus (As): this is generally a uniform gray sheet across the sky, slightly lighter in color than nimbostratus and slightly darker than cirrostratus. They usually cover the whole sky and the sun can be seen shining through them.

Altocumulus

-Altocumulus (Ac): this cloud appears as rolls, or balls all in a patch. They are usually white or gray, and can vary from wavy forms, to rounded forms, to roll-like forms.

Low Clouds: These are found up to 2,000 m (6,500 ft) and include the stratus clouds (dense and grey). When a stratus cloud comes into contact with the ground, it turns into fog.

Cumulus

-Cumulus cloud (Cu): Cumulus means “heap” or “pile” in Latin. These appear as fluffs of wool, and the edges are defined, i.e. you know where the cloud begins and where it ends. These are the most commonly known clouds.

Stratocumulus

-Stratocumulus cloud (Sc): This cloud can be regarded as lots of Cumulus clouds only all mushed and lumped together. This is a very big cloud, and low hanging.

Nimbostratus

-Nimbostratus cloud (Ns): this is a formless cloud which is dark grey in colour. Its name comes from the Latin ‘Nimbus’ meaning rain. It has a smooth grey appearance.

Stratus

-Stratus cloud (St): these are flat, featureless, hazy, clouds. They hang at low altitudes, and colour varies from dark gray to almost white. Weather described as ‘cloudy’ usually means a sky filled with stratus clouds, without being able the see the sun.

I will not be going into Vertical Clouds, but they are basically clouds which have a strong current driving them up. Some sorts of Cumulus clouds are a part of this group.

Did you know clouds are not exclusive to planet Earth, some moons and planets in our solar system also have different clouds of their own?

Images: http://commons.wikimedia.org/wiki/File:Cirrocumulus_to_Altocumulus.JPG, http://www.uvm.edu/~inquiryb/webquest/fa07/efilipek/Journey.html, http://www.biocrawler.com/w/images/archive/3/3b/, http://en.wikipedia.org/wiki/File:AltostratusClouds.jpg, http://cl0uds.wordpress.com/2009/02/04/14/, http://discoverscience.rutgers.edu/extras/weatherwise/clouds.html, http://www.raincalendar.com/2009/07/05/stratocumulus-clouds/, http://en.wikipedia.org/wiki/File:Nimbostratus_before_thunderstorm.jpg, http://en.wikipedia.org/wiki/File:Stratus-Opacus-Uniformis.jpg

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Weather forecast from television

Mankind has always felt the need to be able to predict the weather. As early as 650 BC, people were already looking up at the skies and stars, and recognised certain events which lead to a certain type of weather. Predicting the weather was useful back then mostly for agricultural purposes. Now, it is useful for all sorts of things. People can use it to plan picnics, weddings, the right day to wash the car, and for other various trips which require a certain weather. But forecasting isn’t just used for everyday planning, it is also for warnings of dangerous weather (hurricane, tsunami), by the military to warn officers what the conditions will be during a war, and even now, forecasting is still used for agriculture.
Weather prediction is done now-a-days by specialists with technical equipment, computers, programs, and satellite images. The forecast made by these specialists is spread using the internet, television, radio, and even by word of mouth. There are different techniques available to predict the weather, some more accurate than others. Note that the further the prediction goes, the less accurate the prediction will be, i.e. the prediction for next week is less accurate than the prediction for tomorrow.

A satellite designed to take pictures of the earth to view cloud movement.

1, Persistence: this is when you observe the weather of today to tell the weather of later on. Example, if it is sunny today with no clouds, you can assume it might be sunny tomorrow.
2, Barometer: a barometer is a scientific apparatus that can measure the atmospheric pressure. High pressure in the air indicates the clouds are way up high, meaning they are much lighter, meaning they are not gauged with rain. Low atmospheric pressure means the clouds are very low and almost always ready to let go of their burden, i.e., rain water. The barometer can measure these different types of pressure and it the pressure noticeably keeps rising, it will most probably be nice, but if the pressure drops rapidly, the rain or bad weather is almost always imminent.
3, Sky Watching: the title says it all. Merely observing the sky is a very indication of weather to come. If you notice a great big grey cloud in the distance and there some wind, it is highly possible it will be cold, drizzle, rain, or  even a thunderstorm could happen.

Satellite image.

4, Forecast Models: these are models used in meteorology (science of weather) to determine what should happen. There are models for a lot of events. Basically, a model is something saying that if this should happen, then that will follow soon after. These are used by experts in weather forecasting.
5, Analog Technique: this is what could be called ‘pattern recognition’. This means remembering an event from the past, and remembering the signs and other events that lead to it, and applying it to current events. If the signs match up, it can be assumed the big event will happen again. This is useful for hurricanes, tornadoes, etc.

Images from: nº 1, nº2, nº3.

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The earth is partly made up with rocks. There are many different sorts of rocks that can differ in colour, texture, density, and hardness. All these can be classified into three, big main groups: Igneous, Sedimentary, and Metamorphic rocks.

Igneous Rocks:

This type of rock is a rock that is from cooled down lava. There are two types of rock within this igneous group. There are Intrusive and Extrusive rocks.

Lump of Granite

Intrusive: This is a rock that is solid (cooled down) lava, but it was cooled under ground. The fact that it was under ground and most probably surrounded by more rock caused it to cool extra slowly. The rock had time to create very big crystals before fully cooling. This causes hard, rough and coarse rocks to form. An example of this Intrusive rock would be Granite. Granite is a multi-coloured, coarse rock that can be found in the Wicklow Mountains (Ireland) and are desirable for their durability and colour diversity. It was used along with limestone to build the Great Pyramid by the Egyptians.

Basalt at the Giant's Causeway

Extrusive: This is still cooled down lava, but only this time it was cooled near or on the surface of the ground. This rock is usually much ‘smoother’ because it cools much more quickly and less crystals have the time to form. An example of Extrusive rock would be Basalt. Basalt is a heavy, black, smooth rock. It forms the Giant’s Causeway. Crushed Basalt is used to make asphalt pavement, cement, and sometimes it is found in the foundations of old italian buildings and also used for the slabs of rock in cobbled streets.

Lump of Basalt

Sedimentary Rocks:

This rock was formed with the sediments of dead plants and animals (sometimes sand) at the bottom of the sea bed.

Lump of Sandstone

With the water pressure pushing all these sediments down, a rocky substance starts to form. An example of this rock is Sandstone or Limestone. Sandstone is mainly made from compressed sand under the sea. Sandstone is coarse and red-ish/brown in colour. It is commonly used as building material because of it’s resistance to weathering, and yet easy to handle.

Metamorphic Rocks:

Lump of Marble

Metamorphic rocks are rocks that were formerly one of the two above, but after constant heat and pressure, the rock ‘morphed’ into a new kind of rock. An example of this changement would be Marble. Marble is formerly Limestone, but after receiving constant heat and grinding pressure, a newer (more expensive) rock is formed. Metamorphic Rocks are usually more expensive because they are rarer. It takes more time to create them. First the actual time to create the first rock and then the time for that rock to change.

Reference: Granite image, Giant’s Causeway image, Basalt image, Sandstone image, Marble image.

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Ocean currents are continuous, directed movements of ocean water. These smooth movements of water follow a specific course; they proceed either in a cyclical pattern or as a continuous stream. These movements can be caused by the gravitational pull of the moon, sun, the wind, the temperature, salinity, and the Coriolis force. The Coriolis effect is what happens with the wind because the earth is rotating. The wind in the Northern Hemisphere turns clockwise and the wind in the Southern Hemisphere turns anti-clockwise. There are different types of ocean currents.

Main Surface Currents

Surface ocean currents are created by the wind. A current moving in the top 400 metres of the ocean is considered as a surface ocean current. The Gulf Stream is an example of a surface ocean current. Not all these currents are the same, some are wide and slow, while others are fast and narrow. Some carry heat, and others are cold. The currents are heated at the equator by the sun and then the heat is transported to higher latitudes.

Deep Ocean Currents

Deep ocean currents are like great big rivers on the ocean bed. These use thermohaline circulation. This is when the current passes by Greenland or Antartica and they fill up with cold water. In those cold regions, ice is always being made, but the salt in the water cannot come into the ice, so it stays in the water. When the current passes, it picks up cold, extremely salty water, making it more dense, and it therefore sinks. As it moves along, it loses it cold salty water and starts to come back up. This is called upwelling. Of course it still stays under the ocean surface, because by the time it upwells, it passes by Antartica and fills up with the cold, salty water again and it downwells, the opposite of upwelling.
The Great Conveyer Belt is all the ocean currents (surface and deep) merged together to create a main current to show the general direction of currents.

The Great Conveyor Belt

Images from: http://science.nasa.gov/,http://www.ocean-expeditions.com/,https://fretzreview.wikispaces.com/

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The ‘Columbus Monument’, or the ‘Monument a Colom’ in Catalan, or the ‘Mirador de
Colón’ in Spanish, is a monument to Christopher Columbus (Christopher Colón in Spanish) in Barcelona. This 60m (197 ft) tall monument was constructed in Barcelona for the Exposición Universal de Barcelona (1888). It was placed in Barcelona as a reminder that it was where Columbus first reported back to Queen Isabella and King Ferdinand after his first trip to new found continent.

The idea to build a big monument came from Antoni Fages i Ferrer, who thought it would be cool if the entire thing was built by Catalans. For sixteen years no one liked his idea, until finally, in 1872, it was accepted by the mayor of Barcelona, Francesc Rius i Taulet, and after nine years, the city finally began plans for the construction, in 1881. For the design of the monument, a big contest exclusively for Spaniards was held and the design submitted by Gaietà Buigas i Monravà (a Catalan) was chosen. All of the funding was from Spanish sources, and most of it was privately raised. Also, the entire construction, labor and materials, was done by Catalans, just as the original person who had the idea wanted it to be. The construction began in 1882 and finished six years later in 1888.

This monument has a statue of Columbus on the top. This statue, 7.2m tall (24 ft), was sculpted from bronze by Rafael Atché. Columbus was meant to be pointing towards the New World, while holding a

scroll in the other hand, but when it was placed on top of a big column to make the monument, he was placed in a different way. He is said to be either pointing out to the sea where he landed to report to Queen Isabella and King Ferdinand, or it could be pointing further out towards his home town, Genoa.

There are many other smaller statues representing people related to Columbus, and there are stairs at the base, with four sort of ‘indents’ or entrances, each one flanked by two lions, some standing, others in some sort of crouching/sitting position. There is supposed to be a lift inside the monument which can take up into a viewing platform

just underneath Christopher Columbus, but when I went to see this monument, I didn’t see any open entrances that would lead to a lift. And the column seems pretty thin for an elevator.

Reference:http://en.wikipedia.org/wiki/Columbus_Monument,_Barcelona,

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The greenhouse effect is an effect that happens in the atmosphere with the sun’s heat radiations. The sun projects heat onto the earth and it tries to enter our atmosphere. When the heat comes into contact with the earth, the earth sends it back up. Greenhouse gases trap the hot air and send it back down to earth. Greenhouse gases are mainly Carbon Dioxide, Methane, Water Vapour, Nitrous Oxide and Ozone to name but a few. Carbon Dioxide comes from car exhaust, and us. Methane is a gas that comes from decomposing natural farm wastes such as manure or dead leaves. Water Vapour is basically the clouds. Nitrous Oxide is a relatively unknown gas. Not much is known about it. It is produced naturally and some studies may show that the excessive use of nitrogen fertilizer in farms may increase it. Ozone is not created by human resources but with natural resources. Some hot air does not get caught by the greenhouse gases and it is sent back into outer space. This keeps the earth warm but the warmth is controlled.

However, with the increase in greenhouse gases, more heat gets trapped, causing global warming, and with global warming more water is evaporated creating more clouds (water vapour) even more enhancing this now dangerous effect. This increase is caused by the burning of fossil fuels, leaving waste to rot, or even driving a car.

Although it is named after a greenhouse, this effect does not operate quite exactly the same way. In a greenhouse, the heat is allowed in but not out. In the greenhouse effect, the heat is mostly allowed in and most of that heat is allowed back out. Although now, with more greenhouse gases, less hot air is let out and if we continue, soon this atmospheric effect will live up to it’s name and our world will truly be a greenhouse, leaving no heat escape.

Reference: http://en.wikipedia.org/wiki/Greenhouse_effect,http://earthguide.ucsd.edu/earthguide/diagrams/greenhouse/

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