In the unyielding modern world there can sometimes be no respite from the relentless pace of change and continual improvement. The rapid rate of technological and sociological acceleration means that everyday we are bombarded by such large quantities of stimuli that we barely pause to recognise the wonders that are before our eyes.

There is one phenomena that continually arrests our behaviour, stopping us dead in our tracks. Irrespective of race, creed or status, the stunning nature of solar eclipses leaves a lasting impression upon us all.

What’s An Eclipse?

Eclipses are simply the Moon getting in the way of the Sun, temporarily blocking its view as the satellite continues along its orbit around the Earth.

Solar Eclipses only occur when the Moon is in the New Moon phase of its cycle. Every year there are between two and five Solar Eclipses as the Moon’s transit, either partially or totally, blocks the Sun.

The Luck Of The Draw

The reason why we get total eclipses is purely down to chance and the period of time that we now occupy. In the future total eclipses of the Sun will be a thing of the past on Earth as the Moon moves farther and farther away from us.

The Sun is roughly 400 times the diameter of the Moon. Coincidentally, the distance between the Earth and the Sun is roughly 400 times greater than the distance between the Moon and the Earth.

This quirk means that both the Sun and the Moon appear to be equal in size from the vantage point of the Earth, allowing the Moon to completely block out the Sun as it passes over it.

Types Of Eclipses

There are four types of Solar Eclipses that are dependant upon the trajectory of the Moon’s orbit around and the distance the Moon is from Earth.

Partial Eclipse

A partial eclipse occurs when the Moon only blocks a portion of the Sun. These are the most common type and can be viewed by large amounts of people as the eclipse often covers a large part of the Earth.

Total Eclipse

A total eclipse occurs when the Moon completely blocks out the Sun. Only a small portion of the population can view a total eclipse, as just a small fraction of the Earth’s surface is covered.

Annual Eclipse

Annual eclipses are almost total eclipses, however, a small ring of the Sun remains visible. These occur when the Moon is closer to its apogee cycle (when it is farthest from the Earth) and thus the Moon appears slightly smaller than the Sun from Earth.

Hybrid Eclipse

The rarest of all eclipses is the hybrid. These happen when there is a transition either from a total eclipse to an annual eclipse or vice versa. Depending upon their location, some people will see a total eclipse while others will see an annual eclipse.

Down through the ages solar eclipses have been associated with many different things, most of them bad. Some were put down to supernatural forces while others viewed them as warnings of doom.

For anyone that has had the good fortune to experience a total eclipse it is easy to see understand why they can be so frightening. One minute the earth is saturated with daylight, the next moment it becomes pitch dark as an artificial night is induced.

But we now know better. Free of superstitious beliefs we can enjoy one of the most spectacular sights in the Solar System.

http://www.youtube.com/watch?v=eOvWioz4PoQ

Highly Recommended Reading

Total Solar Eclipses And How To Observe Them gives a great account of how to photograph these awesome sights as well as a detailed explanation of why they occur.

You can obtain Total Solar Eclipses and How to Observe Them here from Amazon.

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The Power And Beauty Of The Solar Eclipse

Tides are caused by a complex interaction between water, wind, gravity, surface tension, earthquakes and the Moon.
One of the most fundamental forces on Earth, tides particular the tides caused by the Moon have been responsible for the creation of life on our planet. Yet it was until only recently that a clear understanding as to how they work has been formed.

The frequency of tides means that they have a great effect upon humanity and life on Earth. This is particularly true of people who live near the coastal areas and fishermen but it affects virtually all of us. The vast majority of goods in the 21st century are transported via ship. Tides are the increases and decreases in the height of our oceans and seas caused by Earth’s rotation, the Moon and the Sun. But at a more basic level they are the longest waves.

What Are Waves?

We often look at water rippling across ponds or waves crashing into coastlines. Waves are ubiquitous. There can be sound waves, light-waves or radio waves amongst others. Ultimately, waves are simply energy.

Waves of water are no different. The water itself does not really move, although there is a slight displacement which corrects itself. Rather the pattern of the wave is what moves – the water stays in the same position.

Water waves are a type of surface wave. Surface waves are waves that pass through two different mediums. In Earth’s case these two mediums are water and the atmosphere.

As the waves move – forces restore the water back into its original position. Two different forces are responsible for returning the water to its previous state -which one is dependant upon the size of the waves. If the wave is less than 1.7 cm (less than one inch) surface tension is the agent. While if the wave is greater than 1.7 centimetres – gravity brings the water back to rest.

Daily Tides And The Moon

The daily ebb and flow of the tide is caused by the Moon’s gravitational pull on Earth. This process is cumbersomely named the Principal Lunar Semidiurnal Constituent. These tides are caused by the Moon’s gravity causing the water to bulge on the nearside of the Earth.

However, the Moon also causes a swell of water on the far side of the planet as well because sphere when pulled on side form ellipses. This is what happens with water on the Earth and what results are the high tides.

In between the two bulges are the areas of low tide. It takes a little over 12 hours for each high tide to occur and of course the same 12 hours between low tides.

http://www.youtube.com/watch?v=rRPtNAA-9UE

Neaps And Spring Tides

The role of the Sun and the Moon becomes more evident in the cases of the twice-monthly neap and spring tides. Spring tides are caused by the Sun, Moon and Earth aligning into a straight line. This happens when the Moon is at either the full or new phase of its month cycle. Spring tides are much higher tides than normal.

Neap tides are the exact opposite. Instead of the forces of the Moon and the Sun both acting on the Earth they cancel each other out. This happens when the Sun and Moon create a right angle with the Earth. Neap tides occur twice a month when the Moon is in its first and third quarter phases. Water levels on Earth are at their lowest during neap tide.

The Big High Tides

Occasionally, every seven to eight months, or so, there is a high tide that exceeds the normal spring tide. This is caused by the Moon being in perigee. That is when it is closest to the Earth. This type of tide is called a perigean spring tide.

The tides play a vital role for navigation. Constant attention must be paid to them as they dictate when ships can enter and leave ports. Animals and plants also rely upon knowing the layouts of the tides. The tide process has directed many systems on Earth over millions of years and it will continue to do so for the conceivable future.

http://www.youtube.com/watch?v=6QXiPo1WZkU

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Waves, Tides and Shallow-Water Processes is a comprehensive book for those looking to discover the details of how waves and water works. It is both accessible and extensive in its approach to covering these fluid dynamics.

You can obtain Waves, Tides and Shallow-Water Processes here from Amazon.

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Tides: Forces We Take For Granted

Freak, monster, and killer are just some of the names attributed to rogue waves.

Ever visit a fishing harbour and notice the big trawlers that have rather large dents in their bows? Were they the result of hitting other ships? No, these dents are caused by powerful waves, rogue waves.

Rogue waves are highly dangerous. They can sink any ship almost instantly, irrespective of size. There have been several documented cases of supertankers being split in two by rogue waves  quickly sinking to the bottom of the sea.

Undoubtedly, the most frightening aspect of these monster waves is the fact that they can occur in any water irrespective of the conditions. Even if the water is dead still, rogue waves can make an appearance. Freaks waves are not the result of tsunamis, or earthquakes. They are entirely independent and many aspects of them are still a mystery.

Walls Of Water

Many people who are fortunate to survive the traumatic experience claim to see a huge wall of water. Because rogue waves contain such an enormous amount of mass, if hit directly the ship has little chance of remaining afloat. It is thought that rogues occur so frequently that perhaps one ship a week makes its way to the bottom of the ocean because of them.

There are no concrete explanations for what causes these freak waves however several theories have been postulated. Some more credible than others.

The Stuff Of Legends

Originally freak waves were confined to legend and myth. Seamen often talked about seeing mountains of water, and incredibly powerful waves. However, the scientific community still remained sceptical about the presence of these rogues. Previous to the acceptance of monster waves, scientists used linear equations which meant that the size of waves were limited by the conditions.

According to this linear model, rogue waves were not possible. The problem with the linear model, that scientists and meteorologists use, is that it vastly underestimates the frequency of these monster waves. Going by this method, the chance of freak waves occurring are so slim that they would only happen once every ten thousand years or so.

From Myth To Fact

The strongest ships are only designed to handle 15 metre waves. This foolhardy method of shipbuilding and the limitations of the linear prediction model were shown up for all to see on New Years Day, 1995. An oil rig called the Druaper Platform experienced a 25.6 metre rogue wave in a storm where the significant wave height was only 12 metres.

If the accuracy of the linear model was to be believed an event like this should only happen once every ten millennia. Scientists and meteorologists from around the world took note as this was the first time that instruments had measured a rogue wave.

The Deadly Cape Of South Africa

The hotbed of rogue waves is South Africa. Perhaps this should come as no surprise seeing as the Cape is one of the most dangerous places for ships.

All along its coast the wreckage of very large ships that have been destroyed by rogue waves is visible. Unfortunately, the Cape is in one of the busiest shipping lanes in the world with billions of euro worth of cargo. The last three decades have seen over 30 ships either sunk or heavily damaged in South Africa. All of these incidents were due to freak waves..

New Patterns And A New Model

After intensively pouring over data gathered on the South African shipwrecks. It was found that each wreck occurred on an ocean current, the Agulhas current. Scientists now had an explanation for these monster waves.

In South Africa it is thought that when this powerful current meets with wind and stormy swells head-on, freak waves are formed. Unfortunately, these conditions are very common in South Africa. But on the flip-side it meant that rogue waves could now be predicted.

It It Looks Too Good To Be True…

Other parts of the world seemed to fit into this South African model. Ships could now avoid rogue waves by plotting alternative courses.

The marine world was uprooted once more on February, 2001, on an Antarctic ship called the Caledonian Star. A huge 30 metre-high rogue wave with an equally gigantic trough smashed into the ship. The windows of the bridge were completely smashed and the navigation instruments and communication instruments were destroyed leaving the ship highly vulnerable. Luckily for the crew and passengers the ship still had its engines running.

A cruise ship, MS Bremen, at the same time and in the same location, was also hit by an unpredictable freak wave. However, unlike the Caledonian Star, the wave caused severe damage and the ship was left adrift, powerless, its side facing into the storm. Just one large wave would have been enough to sink it in this position. For two hours it rolled lifeless completely at the mercy of the ocean until repairs were successfully carried out and power was restored.

No currents that could cause rogue waves exist in the Antarctic. The simple way of predicting these waves is no longer valid.

The Search Continues

The European Space Agency satellites are being employed to scan the world’s oceans, using radar to detect rogue wave patterns. Project MaxWave is so sensitive that it can pick out individual rogue waves. However, the satellites are only there for a tiny portion of the time. In just three weeks ten waves of roughly 26 to 30 metres were recorded in the deep ocean.

Quantum Mechanics And The Non-Linear Model

Eventually, a new theory began to gain credibility and it came from an unusual source, quantum mechanics.

Using a modified version of the non-linear Schrodinger Equation, which is used to predict changes in the quantum world, it began to emerge how these monsters occur.

It is now known that deep water rogue waves occur when one wave absorbs energy from the waves in front and behind it. The rogue is unstable and feeds off the energy getting enormous while decreasing the size of the waves feeding it.

The Common Factor

Unlike normal waves, rogue waves are not smooth relatively gentle inclined slopes. Instead they are vertical walls of water which makes them very dangerous to ships as they are breaking waves. Therefore, the water is falling vertical on top of ships from a great height. Normal waves exert a force of roughly one to two tonnes per square metre, 12 metre storm waves can exerts forces in the region of six tonnes per square metre.

Rogue waves though are very different monsters. They exert huge forces of up to 100 tonnes or more per square metre. Current ships just simply cannot withstand these forces.

We know now that rogue waves can occur, with little warning in deep water away from currents. The only reasonable thing to do now is redesign ships so that they can deal with the huge forces exerted by these monsters.

http://www.youtube.com/watch?v=DUn8WQ4Y1bM

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The Power of the Sea: Tsunamis, Storm Surges, Rogue Waves, and Our Quest to Predict Disasters is an absorbing read that delves into the subjects of tsunamis and other water-based natural events and reveals the frightening effects that our increasingly warmer oceans are having on our planet.

You can obtain here The Power of the Sea: Tsunamis, Storm Surges, Rogue Waves, and Our Quest to Predict Disasters from Amazon.

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Rogue Waves: The Monster Of The Seas

Bolts of lightning can be terrifying experiences. The horrendous crash and rumbling resonance of thunder and the unmistakeable sizzle of superheated air is something that can be very intimidating. Lightning may even be the stuff of science fiction in more ways than is imaginable.

How Does Lightning Happen?

Lightning is the result of the build up of electrical charges in clouds. It occurs in cumulonimbus clouds as they allow negative and positive charges to build up separately at the top and bottom of the cloud. The positively charge ions are at the top and the negatively charged ions at the bottom. This creates huge amounts of electricity which in turn are discharged as lightning bolts.

Although we have a general idea of how lightning forms, as of yet, we do not know the specific details. It is still unclear how the positive and negative charges separate.

Twin Strikes

There are two parts to a flash of lightning. There is the first probe stroke and the second, the brighter return stroke. In other words, the probe stroke is when the electricity hits the ground or transfers to another cloud, the return stroke is seen when the electricity travels up, or returns.

There are two further types of lightning strikes. One is called inter-cloud strikes which are flashes that pass from cloud to cloud and the second are ground strikes which are the more familiar lightning bolts that pass from cloud to ground.

Confusion Between Thunder And Lightning

There is a myth that still permeates to this day that thunder and lightning are different phenomena. Thunder and lightning are the same thing. Thunder is simply the sound of lightning. It is caused by the massive heat generated by a lightning strike which results in a shockwave that is heard as thunder.

The reason why they don’t appear to be related is because sound travels far faster than light. Hence the time lag between seeing the lightning strike and hearing the thunder.

An Electrical Phenomenon

The fastest flashes of lightning travel at a speed in excess of 140,000 kilometres (87,000) miles an hour. This is fast enough to travel around the circumference of the Earth three times. Every second there are 44 lightning strikes, give or take, throughout the world. This amounts to an estimated one billion plus lightning bolts per year.

However, there are areas that are more prone to lightning than others. One obvious example is the tropics which have heavy lightning activity.

Types Of Lightning

There are several types of lightning bolts which are generally different patterns caused by slightly varied conditions. These include ribbon, staccato, forked and bead lightning.

One of the oddest types is ball lightning. This is a sphere of lightning which is said to last for up to a minute, unlike normal lightning which occurs in a fraction of a second.

So far, ball lightning has never been photographed or recorded on video. Nevertheless, scientists have managed to replicate it in experiments using silicon. It is believed that ball lightning occurs when a ground strike hits silicon in the soil.

Beyond Science Fiction

None of these types compare though to the extremely rare but stunning lightning sprites and blue jets. These occur high up well above the troposphere. Sprites are jellyfish like lightning projections of colossal energy that occur over a very large area. They can be red-orange and blue-green and have tendrils that look like jellyfish tentacles.

Blue jets form just above the troposphere and consist of long conical streaks of lightning and, as the name suggests, they are blue in appearance. Elves are another type of lightning that occur high in the mesophere. They are giant reddish discs of light. Elves stands for the very cumbersome and long-winded acronym, Emissions Of Light And Very Low Frequency Perturbations From Electromagnetic Pulse Sources.

Unlike Ball lightning, sprites and blue jets have been photographed and witnessed by countless people. While elves have been recorded by a Space Shuttle mission.

One of the strangest aspects of lightning is the bursts of gamma rays that it causes high above in the Earth’s atmosphere. These extreme high energy gamma waves has been studied with amazing findings.

The tell-tale signature of anti-matter has been detected in the atmosphere.  Anti-matter is a poorly understood phenomena that is the inverse or oppossite of all matter. It is thought to have played a fundamental role in the creation of the universe. It is also the one of the most powerful potential sources of energy in the Universe.

The Allure Of Cheap Energy

Lightning appears to have tremendous potential as a source of energy. One bolt of lightning can consist of millions of volts and tens of thousands of amps of electricity. The peak power of an average lightning  bolt is one terrawatt or a trillion watts of power or 1,000,000,000,000,000 watts. To put this in context, the most energy intensive appliance in a modern home is an electric shower which uses, on average, 9,000 watts.

Tapping into this energy source has long since being a dream of engineers and scientists. However, there are many problems to be overcome.

One of the most obvious hurdles is the ability to store such huge amounts of electricity. Currently, we have no means or doing so. Although some scientists have proposed that lightning could be used to split water in hydrogen.  The next stumbling point is the heat that bolts of lightning emit. At 20,000 to 30,000 degrees Celsius they leave the air several times hotter than the surface of the Sun. We have no current method of practically dealing with such  levels of heat.

Nonetheless, the most obvious problem is that lightning only lasts for a fraction of a second, milliseconds. Therefore, the amount of energy is almost insignificant. Most scientists agree that the real power is contained in the thunderclouds and trying to harness energy from ground strikes is a futile endeavour.

Hit By Lightning

Every year hundreds of thousands of people are hit by lightning strikes. Roughly three out four people survive. It is believed that up to 24,000 people are killed by lightning while 240,000 people are injured each year.

Of those who survive being hit, roughly four-fifths will suffer injuries. Some even lose their personality and suffer other neurological damage.

There are many theories as to why some people survive while others do not. It is thought that lightning flashes over the skin of the survivors with very little of the lightning actually hitting the person. Therefore, the resistance of the skin to electricity plays an important role. It also helps if the person does not have any metal in contact with their skin while being hit.

Recent studies have also suggested that being wet also helps to prevent the huge amounts of electricity from entering the body as the electricity is conducted via the water.

One man, Roy Sullivan, a United States Park ranger, holds the record for the most lightning strikes with seven.

The Most Devastating Lightning

Lightning can be particularly devastating. In the 18th century, over 240 years ago, a lightning strike hit a church in Brescia, Italy.

Unfortunately, and rather bizarrely, the church was storing 100 tonnes of explosive gunpowder. The resulting explosion killed over 3,000 people and destroyed roughly one-sixth of the city.

1994 saw 469 people killed in Egypt as lightning hit fuel tanks. While several planes have been brought down by lightning bolts killing the passengers on board despite aeroplanes having lightning insulators.

http://www.youtube.com/watch?v=0MTz7kdFCak

Highly Recommended Get The Books Through Amazon

All About Lightning is an accessible but comprehensive book that deals with lightning. Lightning: Physics And Effects is a far more comprehensive book that is highly technical. It is one of the definitive books on Lightning and its behaviour.

You can obtain All About Lightning and Lightning: Physics and Effects here from Amazon.

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Lightning: Charged Nature

Earthquakes are one of the most devastating forces of nature. They can occur virtually anywhere on the planet but some locations are much more vulnerable than others. With more than half a million earthquakes occurring annually, roughly one/fifth of these can be felt by humans.  Earthquakes are a much more common phenomenon than people generally imagine.

According to the United States Geological Survey, there are approximately 100 earthquakes a year that are large enough to cause damage.

In Yellow Magpie’s Earthquakes: The Deadliest Of All Shockwaves, we briefly looked at the mechanisms of earthquakes . Here we will take a much closer look at shockwaves. We shall also examine why some buildings cope better than others with earthquakes and why some poorly constructed buildings still managed to remain intact.

Shockwaves

They are three main types of shockwave that are associated with earthquakes. They are P-Waves, S-Waves and  L-Waves. All earthquakes occur where there is movement between massive plates of rock.  As the plates rub off one-another, three different types of shockwaves are formed. Each one behaves differently but only one causes destruction.

P-Waves

The first wave to form is called a P-Wave which is short for primary wave. Primary waves are the first waves formed by the Earthquake. They are also the fastest. P-Waves are created by either push or pull dynamics. In other words, the rock plates moving either towards or away from one another will create P-Waves.

These types of shockwaves travel down deep into the Earth and fortunately do not cause much damage.

S-Waves

Secondary waves or S-Waves are caused by the side-to-side impacts of the rock plates. They have a distinct S-shaped or snake-like pattern. They are the second fastest type of shockwave produced by Earthquakes but they too, like P-Waves, travel down into the surface of the Earth. Because of this they are not particularly destructive either.

L-Waves

Love Waves, or L-Waves, are what causes damage. These shockwaves run along the surface of the earth and are also commonly called surface waves. L-Waves move and distort the surface in an identical manner to the wave pattern of water. They raise and lower the earth in a rolling wave motion. Although they are much slower than P-Waves and S-Waves they can be lethal in large earthquakes.

L-Waves are the last shockwaves to occur when an earthquake happens.

Minimising Property Damage

When earthquakes occur the chances are the vast majority of people will either be inside, or in the immediate vicinity of buildings. Therefore, it is critical that these buildings can stand up to earthquakes especially in areas that are prone to tremors.

Buildings design and engineering becomes critical as sub-standard materials and practices have and do cost the lives of thousands of people.

Structures that are brittle fare the worst in earthquakes – the surface waves can just tear them apart. Reinforced buildings and high specification concrete can save many lives. However, these measures are only good for moderate earthquakes up to about 6 on the Richter Scale. Above this threshold and more flexible designs have to be incorporated.

These type of buildings require foundations built on moving suspensions  and other methods to dissipate the huge forces of energy safely.

Miracle Buildings

In 2008 China experienced a devastating Earthquake that would tear apart the Sichuan Province. 65,000 people were confirmed dead, 374,000 people were injured and a further 18,000 people are still missing and believed to be dead. Furthermore, over four million were left without a home. It is now known that substandard buildings including 7,000 schools contributed greatly to the death toil.

However, what was highly peculiar to engineers were apartments that were left standing. Even though these structures were also sub-standard constructions they did not collapse and disintegrate. The engineers were puzzled so they looked at the design of the building rather than the materials that were used. They found that these apartments had more of a honeycomb structure than the buildings that had collapsed.

In essence, the smaller the rooms and the more pillars and internal walls a building has, the greater its propensity to survive an earthquake.

The Burden Of Life

Earthquakes are not going to go away anytime soon. We just have to continue to live with them as best we can. Our methods of detection and engineering mean that we are in a better position to tolerate them than our ancestors once were.

Though we certainly do not embrace them and they may cause huge loss of life, earthquakes are a sign that our planet is alive, healthy and able to sustain life.

http://www.youtube.com/watch?v=VdHofZVyalQ

Further Reading

Earthshaking Science: What We Know (And What We Don’t Know) About Earthquakes is a good book by Susan Hough. Like all good books on technical subjects it manages to be both comprehensive and readable.

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Devastating Mechanisms Behind Earthquakes And Building Safeguards

The sky darkens, from a dark grey to a deep mauve. Finally it becomes charred black, like something is rinsing the firmanent of all colour, of all life. The previous calm disappears to be replaced with increasingly fast winds. The sound of these winds is pierced only by thunderous hail as ice rocks hurl to earth, battering all in their way.

Ultimately, it arrives, a vast fury of nature. A spinning cloud like no other. It violently wrenches houses and trees from their home with gleeful abandon. The spinning destroyer looms out of the horizon and reveals itself to be a tornado.

A Whirlwind Of Speed

Tornadoes generate the fastest wind speeds out of any storm system. Speeds in excess of 450 kilometres (280 miles) per hour have been recorded in Wichita Falls in Kansas. Tornadoes spin like no other type of storm. But they can be even faster with wind speeds reaching in excess of 650 kilometres (400 miles) per hour.

A Legacy Of Destruction

Tornadoes can occur on any continent although, as of yet, none have been observed in Antarctica. Nonetheless, the one place that is synonymous with them is Tornado Alley, a region of mid-western United States. Every year between 500 and 600 tornadoes hit Tornado Alley causing hundreds of millions of dollars worth of damage and loss of life.

In 1925, a tornado killed 695 people in southern-central United States. This tornado was an abnormality in every way. Named the Tri-State Tornado, it travelled the farthest distance (352 kilometres, 219 miles), had the fastest moving speed (117 kilometres per hour, 73 miles per hour) and lasted the longest at three hours and 30 minutes.

Although a freak in many ways it was not the deadliest. This dubious honour goes to the Daultipuro-Salturia Tornado which killed 1,300 people in Balgaldesh on April 26th, 1989.

Formation, Birth And Death

Tornadoes need a special cloud formation in order to be born. This formation is a type of thunderstorm cloud called a Supercell. Supercells contain areas of air that are constantly rotating, usually several miles above the surface. Rainfall causes the rotating air to lose altitude and approach the ground. As it hits the surface the instantly recognisable funnel begins to form.

When a tornado is created the funnel will form a rotating cloud or a rotating wall cloud. This rotating wall creates powerful gusts of wind that can cause damage several hundred metres or more from the wall cloud.

A mature tornado has a steady supply of warm air which is its energy source. It can travel for over an hour and cover up to 100 kilometres (60 miles). In extreme cases, the eye can be over one kilometre (nearly a mile) across.

Its death occurs when the very thing that breathed it life, the rotating wall cloud, starts to choke it. The wall cloud closes in and cuts off the supply of warm air causing the tornado to dissipate.

The Forefront Of Tornado Detection

Humanity, as of yet, lacks both the resources and the knowledge to prevent tornadoes. The only thing we can currently do is get better at tornado detection. We have come a long way from a time when the only method of identifying tornadoes was through spotters

Today, two primary methods of detection are used. Radar and satellites. Radar, in particular Doppler weather radar stations, is used to identify patterns that may indicate the presence of tornadoes. High above the skies satellites such as the Geostationary Operational Environmental Satellites (GOES) are used.

While tornado spotting is not the only method of detection the part they play in verifying local tornadoes is still critical to preventing loss of life.

Safety And Myths

Tornadoes are deadly forces of nature and they are not to be taken lightly. Unfortunately, there are many myths and misconceptions that surround them. One of the most common mistaken beliefs is the notion that underpass bridges provide protection. In fact, the opposite is true as underpasses can increase their speed and fling fire debris in the path of people who squat under them for safety.

The other great myth is that large cityscapes with their tall, high-rise buildings provide protection. This is simply not the case at all and tornadoes can strike anywhere irrespective of how tall the buildings are or how solid they appear.

The only known place that greatly increases the chances of survival are storm bunkers located in basements.

Tornado Fascination

The awe-inspiring power of tornadoes and our knowledge of what they can do means that they hold a deep fascination to us. They are an interface between the raw and brutal forces of nature and our own humanity.

People travel thousands of miles and cross continents just to get a glimpse of their funnels. Some people get addicted to chasing them. As we learn more and more about our world – our fascination with nature and all it encompasses deepens.

http://www.youtube.com/watch?v=Dx1pG1Eo8X4

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Check out Yellow Magpie’s Hurricanes: Nature’s Most Devastating Storms for insight into another force of nature.

For those looking at an interesting and entertaining read on the subject of hurricanes, look no further than Into the Storm: Violent Tornadoes, Killer Hurricanes, and Death-Defying Adventures in Extreme Weather. This book by Storm Chasers’ Reed Timmer truly captures the visceral experience of hurricanes and high speed winds.

You can obtain Into the Storm: Violent Tornadoes, Killer Hurricanes, and Death-defying Adventures in Extreme Weather here from Amazon.

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For people living in Ireland or the United Kingdom you can access Into the Storm here.

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For those living in Canada you can obtain Into The Storm from here.

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For Germany: Into the Storm.

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For France: Into the Storm.

Tornadoes: A Force Of Nature Like No Other

They are one of the scariest sights in nature. An immense wall of water, far more powerful than concrete or any human- made structure. They can approach transonic speeds and can kill hundreds of thousands of people. Tsunamis are some of the most powerful forces found on Earth.

Earthquakes And Tsunami

A twin force, tsunamis and earthquakes are interlinked. With the exceptions of landslides and volcanoes, earthquakes are generally necessary to form tsunamis. Check out Yellow Magpie’s Earthquakes: The Deadliest Of All Shockwaves for further insight.

In 2004, the tsunami that devastated Sri Lanka, India, Thailand, the Maldives and Africa’s east coast, brought the power and threat of these monster waves to our attention. The Japanese tsunami that followed the massive 9.0 magnitude quake once again opened our eyes to the power of nature.

Normal Waves Versus Tsunami Waves

The difference between ordinary waves and tsunami waves is not dictated to by their size or strength. Rather it is governed by the distance between the crests of the waves. Normal waves are usually separated by roughly 100 to 200 metres. In a tsunami wave, the sea floor gets disturbed and enormous volumes of water are displaced causing the wave patterns in turn to be interfered with. This causes the distance between the waves to be increased. The largest tsunamis can have wave crests that are over 300 miles apart.

Tsunamis In Action

Tsunami waves are only one metre in height out to sea. However, the wave is travelling at tremendous speeds which sometimes exceed 600 miles per hour. The peak or the trough of the wave hits the land first. If the trough of the wave hits first it appears to be like a sudden low tide with the water sucked out to sea. If the peak appears first, it looks like an enormous sudden swell with the typical huge wave.

As the wave comes closer inland the depth of the water decreases. This also causes the wave to lose its speed but the energy must be dissipated and so the wave increases in height. Some of the largest tsunamis can have waves as high as 40 metres which travel inland for several miles.

This initial wave can be followed by a second wave which can actually be more destructive than the first.

Hawaii And Tsunami Detection

Hawaii is one of the most common regions hit by tsunamis. To try and minimise loss of life, Hawaii has one of the most sophisticated early warning systems in the world. The stations monitor seismometers which are placed all over the Earth.

Large Earthquakes are noted and the speed of a tsunami can be calculated based on the depth of water. Therefore, scientists can work out how much time citizens have before the tsunami hits.

In all probability another large Earthquake measuring a 9.0 on the Richter Scale is likely, with the Pacific region being the most prone area.

The Japanese Tsunami

With 8,000 times more energy than the earthquake that devastated Christchurch in New Zealand in 2011 , the earthquake that hit Japan was monstrously powerful. The earthquake’s epicentre was so close to land, at just 72 kilometres (45 miles), that people had very little time to evacuate the area when the tsunami hit.

The Tsunami in Japan was so big that its wave rippled right across the entire pacific hitting continents and returning back to Japan. Pretty much like a giant ripple in a pond.

The tsunamis in 2004 helped scientists to prepare and minimise the damage. Within three minutes of the earthquake occurring, scientists in Hawaii had issued a tsunami warning. Unfortunately, the tsunami struck the coast of Japan just nine minutes after the warning and people struggled to reach safety in time.

The Future And Tsunamis

It is clear that tsunamis will occur periodically. Small tsunamis occur at least twice a year. Larger tsunamis generally occur every 15 years. It has also become clear that there is absolutely nothing that we can do to prevent them.

The one thing we can do is have better detection and early warning systems. We already have made great strives in this area and there is strong evidence to back this up.

Although the Japanese Tsunami claimed the lives of over 11,000 people, without an early warning system the casualties could have reach catastrophic proportions.  The 2004 tsunami that stuck the Indian Ocean killed over 230,000 people. So progress is being made. All we can do is to keep improving our detection systems and hope for the best.

http://www.youtube.com/watch?v=Fzm49fUSCPk

Highly Recommended Get The Book Through Amazon

The Power of the Sea: Tsunamis, Storm Surges, Rogue Waves, and Our Quest to Predict Disasters is an absorbing read that delves into the subjects of tsunamis and other water-based natural events and reveals the frightening effects that our increasingly warmer oceans are having on our planet.

You can obtain here The Power of the Sea: Tsunamis, Storm Surges, Rogue Waves, and Our Quest to Predict Disasters from Amazon.

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For people living in Ireland or the United Kingdom you can access The Power of the Sea: Tsunamis, Storm Surges, Rogue Waves, and Our Quest to Predict Disasters here.

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For Germany: The Power of the Sea: Tsunamis, Storm Surges, Rogue Waves, and Our Quest to Predict Disasters.

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For France: The Power of the Sea: Tsunamis, Storm Surges, Rogue Waves, and Our Quest to Predict Disasters.

Tsunamis: Terrors Of The Oceans

All around the world, a slow destructive drip is turning into a torrent. As humans irrevocably change our landscape, the massive ice sheets are starting to disappear. With this  comes untold devastation and an impact that will be felt by more than one-third of the world’s population.

Many scientists are now coming to the conclusion that these changes cannot be reversed and that we have now become passengers in a run-away behemoth of our own creation.

No Longer Slow-Moving

The normal preconceptions that surround ice-sheets and glaciers are that they are almost immeasurably slow-moving, glacial, after all, is a well-known adjective. Sadly, recently this slow-moving notion has been firmly dispelled. These harsh, seemingly desolate ice-worlds are places that are constantly in flux, during the summer when huge melt-water lakes appear and  suddenly disappear within minutes.

The thing that is most concerning is the rapid acceleration of change within the last decade or so.
These changing rates have been catalogued and we now have accurate projections of what will happen. Timescales have been drawn up but they could well be too conservative.

Human Activity

Changes in the ice have always been part of the life-cycles of the Earth. But what is different is that humans, for the first time, appear to be the drivers of climate change. The ultimate cause of this temperature rises is the burning of fossil fuels.

Some of the most extreme changes can be seen off the west coast of Alaska. Over the four preceding decades temperatures have soared by two degrees Celsius. This is twice the rate of the global average. These rises in temperature  are having a dramatic effect on glaciers and huge chunks or ice are falling into the sea, calving, at an unprecedented rate. The increase in calving is the main contributor to rising sea levels.

Columbia Glacier

One of the most famous glaciers is the Columbia in Alaska. Since the 1980′s the glacier has been losing more ice than is being replaced by snowfall. Scientists have been measuring the speed of the glacier over several years and they have discovered that it has sped up from a rate of 2 metres per day in the 1980′s to its current rate of 16 metres per day.

The Columbia has receded over 16 kilometres during the last three decades. From May 2007 to May 2008, the Columbia Glacier was reduced by over one kilometre.

The Root Cause

Using earthquake monitoring equipment scientists have discovered that water is the main cause of the increased calving. Increased melting on top of the glacier caused the water to rush into the ice, splitting and fracturing it. The water also provides lubrication increasing the speed of the glaciers movement towards the open water.

Some scientists believe that the Columbia Glacier has no future and has long since reached its tipping point, a place of no-return.

What Will No Glaciers Mean?

The destruction of the Columbia Glacier is being echoed all across the world. It is now conservatively estimated that all the world’s glaciers will disappear within the next 50 years. Thus rising sea levels by 30 centimetres. Just this small loss will be devasting to low-lying island communities. But the true cost will be the lack of water for well over one billion people scattered across continental Europe and Asia. People who depend on glaciers for the supply of water. In Asia-alone, one billion people will be directly affected.

The Ice Sheets

However, the real problems are centred on the huge ice sheets of Antarctica, the Artic and Greenland. To put their size in context, if these colasal ice-sheets were to completely melt, the world’s sea levels would rise by an truly apocalyptic 60 metres. Previously, scientists thought that these sheets were simply too large to melt. However, this belief has taken a battering recently as a growing body of evidence suggests otherwise.

Larsen B And Greenland

In 2002, a huge portion of the ice sheet in Antarctica, dubbed Larsen B, completely tore its self from the main sheet. The piece was the size of Luxembourg.

Despite this extraordinary precedence it would not be the only collapse either, as huge portions of the ice shelves would become separated from the main sheet. Thus  thescientific estimates that it would take thousands of years for the ice sheets to melt were turned instantly on their head.

Greenland has also borne the brunt of global warming. In the last decade alone, the country has experienced temperature rises of three degrees. Summers in Greenland are odd times. The hot sun melts the top of the ice sheets causing huge lakes to appear. These meltwater lakes pour through the ice drilling their way through until they reach the bedrock, hundreds of metres below the top of the sheet. The water that gathers from the meltwater lakes acts as a lubricant increasing the speed at which the ice enters the open waters.

The Earth’s Ice History

Ice core samples confirm the cycles of ice ages. These cores provide clear links between rises in greenhouse gases such as CO2 and increasing rises in global temperatures. These reach peaks every 100,000 years or so. At every peak between both CO2 and temperature levels, rises in sea levels followed. The last melting of the ice sheets occured roughly 125,000 years ago. During this period the entire southern portion of Greenland melted and sea levels rose by three metres.

What’s clear though, is that the levels of greenhouse gases have never been as high as they are now. This is a firm indication that the temperature rises are caused by humans.

It is believed that Greenland lost muich of its ice over a period of several centuries if not one thousand years. The next loss however is promising to be very different.

Disappearing Before Our Very Eyes

These highly dynamic systems are best observed through the use of time-lapse cameras. Jakobshavn in Greenland. Jakobshavn is moving at 40 metres per day nearly twice as fast as one decade ago. This is during the melt phase in summer.  Greenland is experiencing a net lose of 150 billion tonnes of ice a year.

In 2008, the largest calving event ever filmed was recorded by David Balog as a section of Glacier, the size of Manhattan Island in New York, tore away from the ice.

http://www.youtube.com/watch?v=LhD7Pz21HBU

How Is The Ice Disappearing?

The melting lakes and water is providing roughly ten per cent of the loss of ice. The other 90 per cent can be attributed to jumps in coastal water temperatures.

In 1997 there was a jump of 1.7 degrees in coastal temperatures which also coincided with the increasing speed in ice calving.

Scientists have discovered that it is the interplay between the cold ice face and the warmer sea waters that is providing the mechanism for the increased ice calving. Near the surface, the water temperature is at its coldest, however, as you go deeper below the surface, the water temperature starts to rise.

Scientists, such as Dr. Ian Howat, now believe that the increased water temperature is providing a convection current. Howat believes that the freezing ice that hits the water’s surface upon calving causes a continuous feedback system. The interaction between the cold and warm water creates a conveyor belt effect that sucks warm water under the base of the ice face, causing it to calve dropping more ice into the water and the cycle endlessly repeats until there is no more ice left.

So, Where Does This Leave Us?

So what does that mean? Conservative estimates state that within 100 years water levels will have risen by 30 centimetres through the lose of our glaciers, a further 30 centimetres through heat causing the oceans to expand and another 30 centimetres through the loss of vast portions of the ice sheets. Fortunately, scientists agree that the polar regions will not melt completely but rather retreat.

With the water almost one metre higher by the year 2100, one billion people’s homes will be under threat from the rising sea levels. Several trillion dollars will be spent on providing sea defences and low-lying regions such as Florida, and Bangladesh will be destroyed. Island communities will entirely disappear.

This scenario could already be certain, the only question that remains is what will people do? Perhaps our greatest challenge will be to adjust our mindset. In future the illusion that we are in control will be well and truly shattered.

http://www.youtube.com/watch?v=et4KEGFIuFQ

Highly Recommended Get The Film Through Amazon

The Truth About Climate Change is a highly polished and accessible film series narrated by the highly accomplished David Attenborough.

Unfortunately, it is not yet available in North America.

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The Melting Ice: The Harsh Reality Of Global Warming

They are one of the most destructive forces found in nature. They can engulf entire countries and kill millions. Yet, we still don’t know what their function is, if they have a function at all. These beasts of nature are hurricanes.

A hurricane or tropical storm system consists of a massive low-pressure center in its eye and thunderstorms that produce strong winds. They rotate counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. They orignate in the doldrums roughly ten degrees north and south of the equator.

‘Typhoon and hurricane are regionally specific words for a tropical cyclone’ according to the author G.J. Holland. Developing over large bodies of warm water, if they go on land they quickly lose their strength and die out.

How Hurricanes Are Formed

Hurricanes are generally found north and south of the doldrums, a place where northern and southern winds meet. They occur because warm air heats the equator causing it to rise. As the warm air rises, cold air takes it place. This zone of cold, low air pressure, can create huge storm fronts.

Meanwhile the hot air travels both north and south to the horse latitudes which are the tropic of Cancer and Capricorn. Once the warm air reaches the horse latitudes it starts to sink back in an area of high pressure. As the air gets colder due to sinking some of it is diverted between the north and south. The cold air returning to the equator becomes the doldrums and so the cycle is repeated endlessly.

These cycles of cold and hot air also provide ideal hurricane conditions.

How Hurricanes Are Classed

Hurricanes are often classified according to the Saffir-Simpson Hurricane Wind Scale. The scale is divided into escalating categories with increasing wind speeds.

• Category one has a wind speed of 119 to 153 kilometres (74 to 95 miles) per hour.
• Category two is between 154 and 177 kilometres (96 to 110 miles) per hour.
• Category three is 178 to 209 kilometres (111 to 130 miles) per hour.
• Category four is 210 to 249 kilometres (131 to 155 miles) per hour.
• Finally category five are winds that exceed 249 kilometres (155 miles) per hour.

The Famous Eye

A large area of sinking air forms the eye of a hurricane. The size of the eye can vary from just a couple of kilometres to over 350 kilometres (220 miles) across.

As the hurricane increases windspeed, the eye becomes smaller. When hurricanes reach the peak of their intensity, the eye walls enclose and the eye can measure less than 30 kilometres (17 miles) in diameter.

The Most Destructive Hurricane

The worst hurricane on record hit Bangladesh in November, 1970. Over one million people were killed due to flooding caused by the storm system.

Hurricanes’ vast size and high winds, which can reach over 300km/hr make them one of the most destructive forces of nature. When hurricanes strike land, they drag high levels of water with them, this is known as a storm surge. The storm surge often causes great flooding and damage to homes.

An average of 11 hurricanes a year hits North America each year and know one needs to be reminded about the devasting effects of Hurricane Katrina.

We may still not know how to stop hurricanes. Or what their role in nature is, but even if we have the knowledge to both understand and stop hurricanes it is unlikely that our fascination with the most destructive storm found in nature will ever diminish.

http://www.youtube.com/watch?v=4f45jA5UxB0

Highly Recommended Get The Book Through Amazon

Check out Yellow Magpie’s Tornadoes: A Force Of Nature Like No Other for insight into an awesome force of nature.

For those looking at an interesting and entertaining read on the subject of hurricanes, look no further than Into the Storm: Violent Tornadoes, Killer Hurricanes, and Death-Defying Adventures in Extreme Weather. This book by storm chasers Reed Timmer truly captures the visceral experience of hurricanes and high speed winds.

You can obtain Into the Storm: Violent Tornadoes, Killer Hurricanes, and Death-defying Adventures in Extreme Weather here from Amazon.

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For people living in Ireland or the United Kingdom you can access Into the Storm here.

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For those living in Canada you can obtain Into The Storm from here.

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For Germany: Into the Storm.

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For France: Into the Storm.

http://www.youtube.com/watch?v=HJydFJORWf4

Hurricanes: Nature’s Most Devastating Storms

A sea of red almost as bright as the Sun bubbles and gurgles in a huge melting cauldron. When the time is right the cauldron will get too heavy, too full. Too much pressure.

A noise that would deafen the sound of 100 Super Jumbos casts its mighty roar. The heavens open, a giant explosion rips through the surface of the Earth sending masses of material into the sky. And then…darkness engulfs the day.

Volcanoes are one of the most powerful forces of nature on Earth. They can cause islands to appear out of the ocean and can also do the exact opposite, force them to disappear into the sea. One of the most awe-inspiring of sights, they can cause great catastrophes and induce mass panic.

Creation Of Volcanoes

Volcanoes are created by ruptures in the Earth’s crust. Fuelled by pockets of molten rock deep underneath the surface called magma, volcanoes allow lava and ash to escape from deep underground in powerful explosions. Magma that manages to break the surface is known as lava.

Volcanoes are generally found where there is tectonic activity. Typically, this activity is a result of either diverging (moving apart) or (converging moving towards) plates. The Mid-Atlantic Ridge is an example of diverging plates while the formation of the Pacific Ring of Fire is a result of converging activity.

Thinning of the Earth’s crust can also result in the formation of volcanoes as in the case of the African Rift Valley.

http://www.youtube.com/watch?v=Bf4iJvrAv-M

Largest Known Eruption

The Greek Island of Santorini erupted with five times the power of Krakatoa in 1470 BC. The entire island was completely destroyed due to the tremendous force of the explosion. A gigantic tidal wave that was created in the aftermath of the eruption caused havoc to the neighbouring island of Crete.

Explosive And Non-Explosive Volcanoes

There are two main types of volcanoes in terms of impact. Explosive and non-explosive.

Explosive volcanoes tend to be highly dramatic and cause a great deal of damage. While non-explosive volcanoes are generally deemed to be safer and less dangerous. The key difference between the two lies in the composition of the magma. Magma that is thin and lacks viscosity is unlikely to explosively erupt. These types of volcanoes typically erupt on a regular basis. There are generally believed to have a low concentration of silica.

Explosive volcanoes on the other hand, are generally the result of underground activity and the collision of tectonic plates. Magma in these types of volcanoes is thick and has large quantities of silica in its composition.

Magma that contains silicates have a tendency to be viscous. The viscous magma thereby plugs the volcano vent. Over time pressure builds and once the magma plug cannot hold the force, the volcano erupts with explosive consequences.

Explosive volcanoes send out masses of lava bursting from the vent and emitting ash and toxic gases into the air in a lethal pyroclastic flow.

Deadly Ash

Volcanic ash is also deadly killer. Ash, which is created by the tremendous heat and force of an eruption, gets sucked up into the atmosphere where it can rain down many kilometres away from the crater. This was largely responsible for the death of the people of Pompeii in Italy.

Benefits Of Volcanoes

Although the exact role of volcanoes is not fully understood, their destructive aspect is countered by the many benefits that they also bring. Volcanic activity has resulted in new land masses forming where previously there was only water and sea.

In November, 1963, a volcanic eruption off the coast of Iceland created a new island called Sertsey. All of Hawaii was created by the same processes.

The reason why people inhabit land so close to volcanoes is because of the fertile nature of the soil. Lava and ash-based soil makes excellent land for agricultural purposes.

Snowball Earth And Volcanoes

It is believed that the Earth was covered in an all-enveloping layer of snow millions of years ago.

‘Snow-Ball’ Earth, as the phenomenon is coined, is a theory that the Earth was completely ice encrusted between 650 to 750 million years ago. It is thought that a series of volcanic eruptions freed the Earth from its icy tomb and allowed life to flourish.

After volcanoes freed the Earth an unrivalled period of growth and life began on Earth. For the first time, complex, multi-cellular organisms emerged from their single-celled offspring. Life would never be the same again.

Largest Active Volcano

The largest known active volcano is Mauna Loa in Hawaii. With a crater 3.5 kilometres (2 miles) in diameter, its latest activity was in 1984. As there is a lack of silica present, the lava has little viscosity and flows like a fluid liquid. Because of this and the low profile of its sides it is known as a shield volcano.

Supervolcanoes

Supervolcanoes are large volcanoes that have the potential to cause enormous devastation on a large if not global scale. Their huge size poses potential difficulties for people and wildlife on Earth.

If such volcanoes did erupt, large amounts of sulphur and ash would penetrate the atmosphere causing the sun’s rays to be blocked. Yellowstone National Park is said to be home to a Supervolcano with the potential to obscure sunlight across the world if it does erupt.

http://www.youtube.com/watch?v=Ap_YUwdiy8I

Toba The Last Supervolcanic Eruption

One of the great mysteries that puzzled scientists and geneticists for years was the relative lack of diversity in the Indian population dating back to roughly 74,000 years ago. The only other race that had such low diversity was the Native Americans and this could be explained by the fact that were cut off from the rest of humanity by the American Continent.

However, India had no such geographical restrictions and the mystery deepened.

Finally, it emerged that a Supervolcano of a similar size as Yellowstone’s erupted 74,000 years ago in Indonesia.

This eruption was enormous. Vast clouds of ash and dust breached the Earth’s atmosphere and some even made it as far as Outer Space. All of this ash travelled west raining down upon India covering much of the land  in a carpet of ash.

This layer of ash caused much turmoil and the Indian people would have faced grave starvation.

http://www.youtube.com/watch?v=-ZDbSZTCix4

Volcano Classification In The Popular Imagination

There is a widespread belief that volcanoes can be easily classified as active, dormant and extinct by their frequency of eruption. Active volcanoes are deemed to be active if they have erupted regularly in the past.

Dormant ones are those who have erupted in recorded times. Extinct volcanoes are ones which not erupted in recorded times.

However, these models are not accurate and have shown to be wrong on more than one occasion.

The Reality Of Volcanoes

In reality, volcanologists consider extinct volcanoes to be ones which have either exhausted or do not have a sufficient lava supply. As a result these types of volcano are deemed unlikely to erupt.

However, even extinct volcanoes can become active by regaining a supply of lava which is possible due to constant changes in the Earth itself. As volcanoes can remain dormant for millions of years, scientists find it difficult to distinguish between these and active volcanoes. Previously-thought-to-be-dormant volcanoes have erupted back into life.

One such example is Soufriere Hills, Montserrat, Bermuda, which became active in 1995. Fourpeaked Mountain, Alaska, is another notable volcano which was long thought to be extinct but which erupted in September, 2006, after nearly 10,000 years of dormancy.

Iceland’s Eyjafjallajökull Volcano

On March 20, 2010, after months of geological activity (including several small earthquakes) Eyjafjallajokull (pronounced AY-yah-fyah-lah-YOH-kuul) erupted. This initial eruption was quite small and caused minimal disturbance.

However, worse was to follow and on April 14, 2010, a more serious eruption resulted melting a large ice-covered glacier. The meltwater which emanated from the glacier in turn caused flooding which led to over 800 people evacuating their homes.

Much of Northern Europe was and continues to be affected by the eruption as thousands of tonnes of volcanic ash is pumped into the air resulting in a giant plume of ash hovering over Europe.

Dangers Of Ash To Aircraft

The ash plume represents severe danger to airplane jets for several different reasons:

• The ash can sandblast both the windows and landing lights of the plane hindering landing and reducing visibility.
• It can interfere with the plane’s navigational instruments such as radio and air speed indicators.
• Volcanic ash can also cause engine failure as it has a tendency to stick to the engines causing them to malfunction.

As the ash plume is ejected by the volcano at a high altitude, the very same altitudes that jets cruise at, it represents a significant threat to flying.

Eyjafjallajokull’s Disruptions

Eyjafjalljakull has caused severe disruption to the aviation industry in Europe. As it is  incredibly dangerous to fly in such conditions, much of the flights have been grounded as a result. The worst affected have been Ireland and Great Britain, while aircraft in Northern Europe and parts of Spain and Portugal have also been forced to remain on the ground.

http://www.youtube.com/watch?v=n6dDesUPkMo

Ireland and Great Britain

Although there are no volcanoes that are considered to be active in the United Kingdom there are several extinct ones. Most notable is Croghan Hill, near Tullamore, County Offaly in Ireland. The remains of an extinct volcano, it is over 26 acres in area and rises some 234 metres (767 feet) in height.

Given what we know about volcanoes it is unlikely that those we consider extinct will continue to be so in the millennia ahead.

http://www.youtube.com/watch?v=DWKWdfJtNl0

Further Reading

Peter Francis and Clive Oppenheimer’s Volcanoes is a comprehensive read, at over 500 pages, on the subject. It lists some of the controversial theories on the functions of volcanoes and the potential impact into the future as well as providing fascinating accounts of how eruptions occur.

Managing to explain the current knowledge of the inner workings of volcanoes in an easy to understand manner without ever resorting to condescension is difficult but Oppenheimer and Francis pull this off marvelously well.

Fisher, Heiken and Hulen’sVolcanoes: Crucibles of Change provides a shorter read at just over 300 pages but covers all the bases in this offering from the volcanologists.

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Volcanoes: Force Of Nature And Wonder

Majestic, dignified and crucial to the planet in which we live, trees are the lungs of the Earth. Acting as giant filters absorbing pollutants from the air, they give us back clean, fresh oxygen to breathe.
Trees are one of the most underestimated and undervalued of natural resources in the world.

Trees accommodate us with shade from the sun and shelter from the rain. They are home to birds, squirrels, monkeys, insects and any other animal or human that wishes to reside in their leafy branches.

In addition, they provide us with medicines, fruits and oils. Trees are one of the most precious gifts nature has bestowed on us. But regrettably,  most of us take trees for granted and many governments and logging companies chop them down indiscriminately. They do so without any thought, or knowledge, of the damage they are causing to the atmosphere and the delicate ecosystems living and depending on the trees for their survival.

The First Trees

The first trees date back to the Devonian period and were more like large primitive ferns than trees. They pollinated through spores instead of seeds. These were known as Archaeopteris and often grew to be over 20 metres (70 feet) high.

When they eventually died, they went back into the ground and helped form the coal , gas and oil we use today. So even in death they continue to give to the Earth.

There are thousands of tree species in the world but sadly, because of the constant felling of trees, we are losing a valuable and fundamental resource. For example, rainforests used to cover 14% of the Earth’s surface, today just 6% remains.

Rainforests provide 20% of the world’s oxygen and many believe that the last remaining rainforests will have disappeared in 40 years’ time.

With the destruction of the rainforests comes not only the catastrophic loss of the trees themselves but also the disappearance of animals, insects and the tribes who live among the rainforests. With the dispersal of these tribes, in particular, the Amazonian peoples, comes the extinction of thousands of years of knowledge of trees and their medicinal properties.

Tree’s Use In Medicine

Trees have been valued for years for their curative qualities. Many of today’s medicines are procured from trees, for example, Taxol, which is used in the chemotherapy treatment of Breast Cancer, is derived from the  Yew Tree. Meanwhile, the bark of the Willow Tree contains salicin which is similar to aspirin and can be used in the treatment of pains. The Eucalyptus Tree is the source of the antiseptic oil used in aromatherapy, while Pine Nuts and Pine Needles are renowned for treating breathing problems. There are countless other examples of medicines coming from trees.

Other species of trees produce luscious fruits, like apples, oranges, plumbs, coconuts, bananas…the list goes on. Just what is inside a tree that can produce such succulent fruits is a mystery, but yet from this massive plant comes delicate colourful health-giving fruits, complete with skin and juicy contents, giving us nourishment and vital vitamins and minerals.

The Oldest Living Tree

Trees have been on the Earth long before humans and often live to be thousands of years old. Even in old age, trees can still remain strong and sturdy, with their ageless character and vim intact.

‘Methuselah’ is said to be the oldest living tree in the world. Methuselah is a Great Basin Bristlecone Pine almost 5000 years old. It is located in California.

Scientists can tell the age of a tree through dendrochronology. From studying a tree, they can learn about insect activity. They can even tell if a tree was damaged by storms or even if it survived a forest fire.

They can do this by examining fallen trees nearby of the same type and size. Another way is to count the rings (called dendrochronology) on the trunk of a cut tree. Each ring pattern represents a year in the life of the tree. The different colours correspond to springwood and summerwood. The lighter coloured wood is normally the springwood with the darker being summerwood.

From The Tallest To The Smallest

Some of the most impressive trees in the world in terms of height are the Californian Coast Redwood trees. Indeed among them is said to be the tallest tree in the world measuring 115.55 metres (378 feet 9 inches).

In contrast, the pygmy forests, which are also situated in California, in the Gulch State Park, North of San Francisco, are among the smallest in the world. The soil in the park has stunted the growth and some of the trees are only 15 centimetres (6 inches) high.

‘Trees are the wellsprings from which pour forth life, breath and health. Ignore them and they will still be generous but chop them down and we cut short our own mortality.

http://www.youtube.com/watch?v=iTtjXfc9HJY

Recommended

‘Meetings With Remarkable Trees‘ by Thomas Pakenham is a wonderful book. Full of vivid pictures, it is an excellent accompaniment for anyone with an interest in life-preserving trees.

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Trees: A Vital Resource To Be Treasured

The Altamira Cave, is located near Santillana del Mar, Santander, Spain. The cave is famous for its paleolithic cave paintings of wild animals in red, charcoal and ochre and is frequently described as the Sistine Chapel of Palaeolithic Art. What is astonishing about the paintings is that they look like modern art yet they are between 14 and 18,000 years old.

The Cave measures 270 metres long and is made up of various rooms and passages in an S shape. With the main chamber measuring 18m by 9m.

Discovery

In 1879 María Justina, the nine year old daughter of amateur archaeologist Marcelinon Sanz de Sautuola, discovered a series of drawings and paintings on the roof of the cave. Her father had been searching for artifacts in the cave when his daughter cried out ‘Look, Papa, oxen’. The paintings and drawings depicted wild animals including bison, red deer, boar and horses along with paintings of human hands.

Sautuola and archaeologist Juan Vilanovoy Piera from the University of Madrid, together excavated the cave. And in 1880 they publicised their findings in Braves apuntes alaunos objetos prehistoricas de la provincial de Santander, in which they concluded the paintings dated to the Paleolithic Period.

Thought To Be Forgeries

The findings of Sautola and Piera were dismissed by French specialists Gabriel de Mortilet and Emile Cartailhac, and at the 1880 Prehistorical Congress in Lisbon, their hypothesis was loudly rejected as nonsense.

The Catholic Church also became involved and was anxious to discredit the paintings for fear it might focus on evolution and put into question the omnipresence of God.

At one point, because of the well preserved nature of the paintings, Sautuola was even accused of forgery by a fellow country man who suggested Sautuola had hired someone to produce the paintings.

Marcelinon’s Vindication

In 1902 a number of other prehistoric paintings were discovered which served to convince experts that the Altamira paintings were indeed genuine.

That same year Emile Cartailhac admitted he had been wrong in his condemnation of the findings of Sautuola and published an article in the journal L’Anthropologie, entitled ‘Mea culpa d’une sceptique’.

However, his apology came too late for Sautuola who didn’t live to see his good name restored or his conclusions vindicated, as he had died 14 years earlier.

Artifacts have been found in the cave that date from as early as the 18,500 years ago and as early as 14,000 years ago covering the Upper Solutrean and Lower Magdalenean Periods. It appears that a rockfall had sealed off the cave roughly 13,000 years ago.

Excavations Continue

Excavations continued from 1902 to 1904 by Hermilio Alcalde del Rio and by the German Hugo Obermaier from 1924 to 1925 and finally by Joaquin Gonzalez Echegaray in 1981.

In 1985 the cave was enrolled into the UNESCO’s World Heritage List.

During the 1960s and 1970s the paintings were becoming badly damaged by the carbon dioxide emitted from the breath of the crowds of people who flocked to see the historic chambers. So in 1977, the cave was closed to the public. It was reopened in 1982 but with very limited access. Finally in 2001 a replica cave was opened and the original cave was closed completely.

The replica is described as a faithful reproduction of the original with the colours and pigments fashioned from similar powders used in the original.

Altamira’s Powerful Impact

Following a visit to the cave Picasso is quoted as saying ‘Beyone Altamira all is decadence’.

In 1999 the rock group Steely Dan188 released their song in honour of the caves, called ‘The Caves of Altamira’.

http://www.youtube.com/watch?v=HmD6Lo9-l3s

Further Reading

The Cave of Altamira is the definitive book on the subject and shows just how modern these ancient peoples’ art really was.

Cave Paintings and The Human Spirit is a cheaper book which covers many known cave paintings including Altamira.

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The Cave Of Altamira: Modern Art Happened 18,000 Years Ago

A room suddenly grows dark, ripped of its man-made supply of electricity. The walls of the room start to emit faint groans as plaster dust is deposited from an ever-cracking ceiling.

A claustrophobic sense of dread grips the occupants as they try in vain to nobly suppress their rising panic. The denial of mortality is firmly cast aside as they realise that they caught up in nature’s true fury, an Earthquake.

Few acts of nature are as a powerful or awesome as earthquakes. Caused by shockwaves from deep inside the Earth’s crust, they have the potential to decimate skyscrapers and cause great upheavals in landmasses. Some are so powerful that they can be felt from the other side of the planet.

What Causes Earthquakes?

The word earthquake is used to describe a seismic event. So under this definition, an earthquake can be a natural event or caused by people’s actions.

Earthquakes can be caused by a multitude of different sources such as volcanic eruptions. However, the vast majority of them occur because of movement in tectonic plates which are faults in the Earth’s crust. These seismic waves travel through the ground at speeds of up to 20 times faster than the speed of sound. If a sufficiently large earthquake occurs out at sea, a tsunami or tidal wave may result. Earthquakes can also bring about landslides and volcanic eruptions.

The focus of an earthquake is known as the hypocentre. The epicentre is the area of ground directly above the hypocentre this is where an earthquake’s power is greatest. An earthquake’s power diminishes the farther away the wave travels.

http://www.youtube.com/watch?v=P53OJd_lxew

Most Destructive Earthquake

The most destructive earthquake on record in terms of human fatalities happened in 1556 in the Shensi Province in China. As many as 800,000 people lost their lives.

A more recent earthquake in 1976 is said to have caused nearly as many deaths in Tangshan, China. However, the exact amount is not known as the Chinese authorities have not revealed the true number of fatalities.

Earthquakes can also induce mass panic and fear. People often die in the panic that ensues when an earthquake hits a highly populated area.

http://www.youtube.com/watch?v=CtBXTvtFaCU

Richter Scale

The most widely used method of measuring the size of an earthquake is the Richter Scale. The height of the recorded waves on a seisometer, which measures underground vibrations, are used to indicate the magnitude of the earthquake. The intensity of an earthquake is recorded by the Mercalli scale.

However, not all earthquakes of similar magnitude do the same amount of damage. There are many other variables to take into account such as ground conditions (whether the ground is hard or soft) and how far the hypocentre is below the surface.

The Three Faults

Earthquakes occur along three major types of faults. Strike-slip reverse and faults. Areas where the crust is being extended such as when techtonic plates are separating, give rise to normal faulting. Reverse faults occur when techtonic plates are colliding. In such casese the Earth’s crust is being shortened. Slip-faults are when landmasses or plates rub off one another in a horizontal fashion. One of the most famous areas of Earthquake activity is the San Andreas fault. It is an example of a strike slip fault.

Aftershocks

Aftershocks are earthquakes that occur after the initial event called the mainshock. They are always of a smaller magnitude than the first earthquake. If an aftershock does exceed the magnitude of the first shock then it is reclassified as being the mainshock and the previous shock is called a foreshock. Aftershocks are the result of the Earth’s crust readjusting to the effects of the main shock.

Earthquakes have many different effects. Violent shaking can often destroy buildings that are close to the epicentre of an earthquake. The ground can also visibly rupture and can have devastating impact on buildings and structures.

Earthquake Prediction

Scientist are getting better at predicting where an earthquake is likely to strike. So-called earthquake storms are proving to be key to forecasting future quakes.

Similar to aftershocks, earthquake storms take place years apart. There haa even been a successful prediction in Izmit, Turkey, which went unheeded killing between 20 and 30 thousand people. It has now emerged that there is a fault running through Turkey that is the equivalent of the San Andres in the United States.

However, a serious earthquake in Turkey would have much more devastating consequences than its equivalent in the US due to type of buildings in Turkey.

Although it isn’t possible to forecast when an earthquake will happen, it is possible to indicate where it is likely to strike. There has been a great improvement in constructing bulidings which are able to counter the seismic effects of earthquakes and reduce fatalities.

http://www.youtube.com/watch?v=e8aEA-xI1gg

Earthquakes And Threat Of Fire

Because earthquakes often brake gas and electric powerlines there is a high risk of fires breaking out when ever an earthquake occurs. In 1906, San Francisco was reduced to a smouldering rubble after fires destroyed it in the wake of an earthquake.

Soil Liquefaction

Soil liquefaction occurs in sandy, granular material which temporalily lose their strength at a molecular level due to extreme vibrations. When combined with water in an earthquake these materials act as a liquid rather than a solid. Buildings and other structures can fall victim to liquefaction and sink into the temporarily liquid ground.

Earthquakes And Tsunamis

Earthquakes at sea often cause tsunamis or tidal waves. However, not all earthquakes will result in a tsunami or tidal wave. Generally, it takes an earthquake greater than magnitude 7 to cause a tsunami. Vibrations and sudden ruptures cause masses of water to become displaced. Waves can reach heights as great as 500 metres (1,700 feet) as was the case in Lituya Bay, Alaska, in July 9, 1958. Lituya Bay is home to the largest known tidal wave.

Earthquakes often bring floods and case cause widespread disease as they leave unsanitary living conditions caused by ruptured sewerage services and lack of food due to crop damage. They are often linked to volcanic activity, this is especially true of the Mount St Helens eruption in 1980.

Check out Yellow Magpie’s Tsunamis: Terrors Of The Oceans for further insight.

Earthquake Prevalence

It is thought that much of the world is built on tiny faults in the Earth’s crust. Places that were deemed to be unaffected by earthquakes are also at risk. There are constant earth tremors that are seldom felt by people.

Even Ireland or Great Britain experience tremors from time to time. In 1984 an earthquake in Wales was felt in Ireland. Measuring 5.4 on the Richter Scale, it originated at North Lyn, in Northern Wales and was the largest recorded in over 100 years.

Some animals sensitivity to earthquakes is well-documented. They probably detect small warning tremors that are a signal of a eminent eruption. There have been countless cases of animals saving people because of their keen senses. One such animal that is said to have a close relationship with earthquakes according to legend is the catfish.

http://www.youtube.com/watch?v=VdHofZVyalQ

Further Reading

Check out Yellow Magpie’s Devastating Mechanisms Behind Earthquakes And Building Safeguards for closer look at shockwaves and earthquake buildings.

Earthshaking Science: What We Know (And What We Don’t Know) About Earthquakes is a good book by Susan Hough. Like all good books on technical subjects it manages to be both comprehensive and readable.

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For people living in Ireland or the United Kingdom you can access Earthshaking Science: What We Know (And What We Don’t Know) About Earthquakes here:

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For those living in Canada you can obtain Earthshaking Science: What We Know (And What We Don’t Know) About Earthquakes from here.

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For Germany: Earthshaking Science: What We Know (And What We Don’t Know) About Earthquakes.

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For France: Earthshaking Science: What We Know (And What We Don’t Know) About Earthquakes.

Earthquakes: The Deadliest Of All Shockwaves