Atlantic storm waves, not tsunamis, lifted 50-tonne boulders along northwest coast

Boulders pictured here at Annagh Head Co Mayo, some weighing more than 50 tonnes were lifted by Atlantic storm waves, not tsunamis [Pictured: NUI Galway]

The massive boulders deposited at Annagh Head in Mayo, and possibly some other locations along the northwest coastline of Ireland were not caused by a tsunami, but by storm waves breaking on the foreshore for hundreds of years.

That’s according to research by Professor Paul Ryan from Earth and Ocean Sciences in the School of Natural Sciences at NUI Galway and the University of Oxford published in the Proceedings of the National Academy of Sciences.

“This study shows the enormous power of storm waves battering the foreshore over centuries, ripping boulders of over 50 tonnes from the cliff face, piling them 100 metres or more inland,” said Professor Ryan.

The researchers found that the huge boulders, some over 50 tonnes, which are piled at the top of a small cliff, got there due to battering from storm waves.

It had been speculated that many of the larger boulders along the west coast of Ireland had been uplifted by tsunamis, but in 2004, the late Professor Michael Williams argued that the boulders on the Atlantic cliffs of the Aran Islands were due to storm waves, not tsunamis. This thesis caused caused considerable international debate at the time.

The researchers here set out to resolve the debate as to whether the large boulders had been moved by tsunamis or storm waves.  They used computer simulations, hydrodynamic equations, as well as oceanographic, historical, and field data. These found that the boulders are a cliff-top storm deposit.

Northeast Atlantic storms can produce waves of over 60 metres, which are capable of lifting massive boulders. This knowledge is important in the context of climate change, the researchers said.

Shorelines are becoming more vulnerable and the ability to understand these piles of boulders along the west coasts will help us understand how much more vulnerable we actually are to storms, the researchers said.

 

Abrupt Climate Change; a clear and present danger to life on Earth

CLICK ABOVE to listen to discussion on the topic of abrupt climate change with Keelin Shanley on Today with Sean O’Rourke (broadcast 14th August 2015)

The Gulf Stream

The Gulf Stream is threatened by rapid melting of the West Greenland Ice Sheet, and if it was cut off, this could trigger rapid and severe global cooling (Credit: http://www.marketoracle.co.uk)

We tend to think of climate change as something which happens very slowly. perhaps over centuries, causing sea levels to rise a little perhaps or winter storms to get a little worse.

Perhaps this explains why there is no real sense of panic when stories come out about the latest appalling new threat to the stability of our global climate.

We have grown accustomed to such stories, and we don’t appear to believe that climate changes, which we all know are coming, will affect us too much in our lifetimes.

We tend to think of climate change as something which happens very slowly. perhaps over centuries, causing sea levels to rise a little perhaps or winter storms to get a little worse.

Perhaps this explains why there is no real sense of panic when stories come out about the latest appalling new threat to the stability of our global climate.

We have grown accustomed to such stories, and we don’t appear to believe that climate changes, which we all know are coming, will affect us too much in our lifetimes.

There is also confidence that human ingenuity, technology and engineering will come to the rescue to make sure that we don’t suffer too much inconvenience from any climate changes.

Yet, all this complacency is totally unwarranted, scientists believe, as there is plenty of scientific evidence to show that the Earth has gone through both rapid cooling and warming in the past; even before humans appeared on the scene.

Mammoth

Even some of the biggest creatures that ever walked the Earth have gone extinct due to very rapid climate change.

Most famously, there were the dinosaurs, but new research indicates in more recent times, rapid climate change was the primary reason behind the extinction of the Woolly Mammoth, a big, hairy elephant.

The Woolly Mammoth roamed large parts of the Earth for millions of years until its numbers declined 10,000 years ago, then disappeared about 4,000 years ago.

One of the most popular theories for why the Mammoth disappeared was because of over-hunting by hunter-gathering human societies.

However, the latest research indicates that the Mammoth, along with some bear species and cave lions went extinct due to rapid climate warming, not hunting.

At the end of the last Ice Age, the planet warmed by 16 Celsius in a matter of decades, then cooled, then warmed again. The Mammoth and other species couldn’t adjust.

The scientists examined Greenland ‘ice cores’, DNA studies from the bones of extinct Mammoths and the sedimentary record, and compared all of these.

The ice cores are taken by drilling deep into Greenland ice. This provides a geological record going back thousands, even millions of years into the Earth’s past.

The cores are a bit like tree rings, in that they can show when the climate has rapidly warmed or cooled and whether a volcanic explosion was the cause, or not.

Comparative DNA studies can tell you about how quickly a species disappeared, and what other species replaced it – which gives a clue to the extent of climate change.

It was not just the Mammoth that had trouble during this period of rapid cooling and warming about 12,000 years ago, lots of other species went extinct too.

The period from 10,900 BC to 9,500 BC is called the Big Freeze, or Younger Dryas as it’s known to scientists, where the Earth became very cold and experienced drought.

The onset of the Big Freeze, scientists believe, happened extremely fast, possibly inside a decade, and the end of the event was equally fast.

The evidence for this is seen in ice and sediments, and the fossilized remains of pollen and mammals.

As well as the Mammoths, many of the large vertebrates that dominated the last Ice Age died off during the Younger Dryas abrupt climate changes.

These included the short-faced bears, saber toothed tigers, giant sloths and mastodons.

Rapid

These past climate changes had nothing to do with us, of course, but they happened very quickly, and saw enormous changes in global climate and sea levels.

Humans managed to survive the changes, probably because of their flexibility and large brains which made them better capable of finding survival solutions.

However, climate induced ‘mass extinctions’, such as the one that affected the dinosaurs, have wiped out more than half of the Earth’s life forms in the past.

It can, and will, happen again, the only questions are when? and how?

Cycle

Most agree that we are entering a period of ‘natural’ warming, but there is also little doubt that mankind is pushing the natural warming cycle which is happening.

It’s important to draw a distinction here between ‘normal’ climate change, if you like, and ‘abrupt’ climate change, which happens faster, and is a lot more dangerous.

Abrupt climate change has happened inside a decade in the Earth’s past, and there is every reason to believe why the same couldn’t happen again.

Reputable climate scientists predict that the Earth will warm by an average of between 2 Celsius and 6 Celsius by the end of this century.

There is ‘normal climate change, if you like,  which is a worry in its own right, but then there is the far more ‘clear and present danger’ of abrupt climate change.

With ‘regular’ climate change, scientists believe that sea levels may rise by 2 metres and temperatures by about 4 Celsius, globally, by the end of this century.

These kind of changes over that period of time can be contained by mankind, using engineering and technology, although it won’t be easy or with massive costs.

For example, the best current estimates are that it will cost several billion to protect the city of Dublin alone from future likely climate events.

But, this is economics and maybe a century down the road, why do we need to worry now, you might ask? Don’t people have more pressing things to worry about?

Well, the worry is that the natural cycle of warming, when ‘pushed’ by human activities could push us past a ‘tipping point’ where climate changes rapidly.

The term ‘tipping point’ which was used during the Iraq war, when the statue of Saddam was torn down in Baghdad and people lost their fear of the regime.

[The origin of the term is from Malcolm Gladwell’s book called ‘The Tipping Point; How Little Things Can Make a Big Difference’]

With climate change it is similar. There can be an accumulation of factors, perhaps small in their own right, that push the climate past a ‘tipping point’.

In climate terms, the tipping point is when abrupt climate change is triggered, and mankind cannot control it, and no-one can predict the possible final outcome.

Rapid climate change ,can also be caused ‘natural’ events which are beyond our control, such as eruptions of ‘Supervolcanoes’, or being hit by comets.

Tipping point

Well, one possible scenario was depicted in The Day After Tomorrow, a Hollywood film from 2004, starring Dennis Quaid and Jake Gyllenhaal.

This is the most likely way that humans could ‘drive’ abrupt climate change.

In this film, which was based on real science, we see breaking off of a piece of the Larsen Ice Shelf, which is part of the Antarctic landmass.

At the same time, ice in the North pole floods into the North Atlantic, cutting off the North Atlantic Current, and disrupting other sub ocean currents.

In the real word, many scientists believe that the melting of the West Greenland Ice Sheet, which is underway, could also cut off this current.

The North Atlantic Current, is an extension of the Gulf Stream, which keeps Ireland ice-free, and without it, Europe and North America would become a tundra.

Allied to this, there are superstorms, which may believe would arise in this scenario, and the whole global weather pattern is thrown into chaos.

Many of the great cities of North America and Europe, – in the film – are buried under snow and ice, and US refugees, ironically, try to gain access to Mexico.

It’s Hollywood, it’s a film, but it’s based on real world climate ‘modeling’ scenarios, and the result was only parts of the globe remain habitable for human beings.

This is all largely down to mankind ‘pushing’ the climate cycle, by releasing carbon dioxide ‘greenhouse gas’ into the atmosphere and causing ice at the two poles to melt. However, tipping points have been reached in the past too ‘naturally’.

Lake Toba Location

The location of Lake Toba where the most recent Supervolcanic eruption took place. The emerging humans only survived in small numbers

Supervolcanoes

The biggest threat, in the ‘uncontrollable’ category, by far, is of an eruption by a ‘Supervolcano’ – of which there are about six in the world.

The two most famous, which people may have seen on National Geographic or Discovery are the ones at Yellowstone in the US, and at Lake Toba, Indonesia.

If either of these went off, and there are others, like I said, we’d be in enormous trouble; all of us, not just those living in close proximity to the eruption.

A supervolcano is one which has an enormous amount of magma in its chamber and has the ability to cause devastation to a wide area and change global weather.

Let’s take Lake Toba. The last time it erupted was 74,000 years ago. Its impact was so colossal it caused a ‘volcanic winter’, with huge, and rapid cooling of the Earth.

This led to ‘mass extinctions’ of the majority of plant and animal species alive at the time, and early humans were one of the fortunate species to survive the event.

A Supervolcano is totally different to anything most people understand about volcanic eruptions, even the worst of them, going back hundreds of years.

For example, the eruption of Krakatoa in 1883, also in what is now Indonesia, killed 36,000 people – at least, and its explosion was heard 4,500 km away in Perth.

That famous eruption, caused a drop in global temperatures of 1.2 Celsius and a general cooling of the Earth’s climate for at least 15 years afterwards.

Consider this then:

Krakatoa expelled 45 cubic km of volcanic material. Toba expelled 2,800 cubic km, making it vastly more powerful and bigger than Krakatoa.

Frighteningly, Krakatoa’s eruption, which was tiny compared to Toba, was estimated to have the force of 200 mega tonnes of TNT explosive, compared to 20 mega tonnes for the Hiroshima bomb.

Toba, it has been estimated had 10,000 times the explosive force of Mount St. Helen’s which some might remember erupting in 1980, flattening all around it.

Scientists have linked the Toba eruption to a ‘Volcanic Winter’ which caused the planet to rapidly cool by 5 Celsius and to be plunged into a 1,000 year Ice Age.

The rapid cooling of the planet had an immediate and almost life-ending impact on early humans.

Scientists have reported that evidence from DNA studies has shown that the numbers of humans dwindled to a tiny number in the aftermath of Toba.

Researchers finally found an answer to the mystery of the ‘evolutionary bottleneck’ where the diversity of the human species shrank dramatically 74,000 years ago.

These kind of super eruptions are not as rare as we’d like to think.

Scientists have recorded at least 4 major Toba eruptions, and there are at least five other known Supervolcanoes; Long Valley, California; west of Santa Fe, New Mexico; Taupo Caldera, New Zealand; and Aira Caldera, Southern Japan.

Sun

The Sun is another element that has an important role, scientists believe, to play in climate change; even rapid climate change.

There is a solar cycle every 11 years during which there is a solar maximum when the Sun’s activity peaks and a solar minimum when it troughs.

There are also bigger solar cycles that go across centuries of time.

The simple way to measure solar activity is to look at its sunspots. The more sunspots the more solar activity, the less there are, then the less activity there is.

The “Maunder Minimum’ refers to a time when Sunspots almost disappear, and the sun’s activity is very low. Two Irish astronomers, Annie and William Maunder spotted this when looking at historical records, and their own observations.

Between 1645 and 1715 there was a Maunder Minimum when Sunspots disappeared, and the Earth cooled to the extent it has been called ‘The Little Ice AGe.

In London, for example, the Thames froze over in winter far more often than today, and a tradition of Frost Fairs grew up, which lasted into the 19th century.

As well as people doing business of all sorts on the ice, there were even ‘Ice Taxis’ to transport well-oiled revellers to and from their social engagements on the ice.

The Irish climate during this time, was like that of south western Iceland today, with average temperature year round of 6.8 Celsius compared to about 10 Celsius today.

Some business interests have tried to link all climate change, big or small, fast or slow, to solar cycles, and they deny the impact of mankind on it whatsoever.

Impacts

Asteroids and comets impacting Earth are another thing to consider in this.

The biggest asteroid  impact to be recorded by geologists is the one which hit the Yucatan peninsula in Mexico 65 or 66 million.

This is called the Chicxulub impact crater.

This was large enough to cause mega-tsunamis, global firestorms, and trigger earthquakes and volcanoes, but also to cause rapid climate change.

A lot of carbon dioxide ‘greenhouse gas’ would have been released into the atmosphere from the breakdown of carbonate asteroid rocks like calcite.

This caused a very quick warming of the Earth, of a couple of degrees C, followed by a longer term cooling, as the dust from the impact blocked out the sun.

The dinosaurs, and most of the life then on Earth, couldn’t cope and went extinct.

The impact crater measures 180 km in diameter and is about 20 km deep.  That’s about the distance from Maynooth to Galway city diametre-wise.

The idea of an asteroid impact killing the dinosaurs was first proposed by Luis and Walter Alvarez in 1980, and it has since stood up to rigorous testing.

The impact resulted in the extinction of three-quarters of the other species of plants and animals on the Earth in one of the most famous ‘mass extinction’ events.

This wipe out opened the door to new species, mammals and ultimately to ourselves, as new creatures, better adapted to new conditions, began to thrive.

The extinction of most of life on Earth leaves opportunities for the few that survive.

What can we do?

Well, one thing we can certainly do is to reduce emissions of carbon dioxide before we push our climate past its ‘tipping point’.

I suspect, however, that it would take a colossal, rapid change in our climate for politicians and many people to wake up to the threat.

Unfortunately, that would be too late. It would be like trying to give someone a new cancer treatment when the disease has spread to all major organs of the body.

I would ask people to think again, and realise that abrupt climate is a real possibility and that if it is allowed to happen, no technology on Earth could reverse it.

In terms of the Sun and the impact of its cycles on global climate, there is not too much we can do, but we are getting better at predicting long term Solar cycles.

However, even if we face a Little Ice Age, as caused by the sun a few centuries ago, I’d be confident that we’d have the ability to survive it, although it wouldn’t be pleasant.

On comet and asteroid impacts. Again, scientists are getting very good at developing methods of warning us well in advance of something that could hit Earth.

I’d be confident here too, as, if we are faced with an asteroid about to hit us inside a few years or decades we will use our ingenuity to develop a way to divert it.

This could be by using lasers, or something else to nudge it slightly off its path, so that it swings by us.

The big threat, as with so many other things, to us from abrupt climate change is from our own activities, and this is where I worry about inaction.

End of reading glasses; social media ‘unsocial’; making human organs; Icelandic volcano threat

Discussion of some of the week’s’ top science news stories on East Coast FM’s The Morning Show with Declan Meehan (broadcast on 28th August 2014) 

 

World expert in tsunamis to speak in Dublin

Lisbon Earthquake

The Great Lisbon Earthquake of 1755 devastated the city and the resulting tsunami hit southwest Ireland

A world expert on earthquakes and tsunamis will be in Dublin in February to discuss the latest research into how these events can be more reliably anticipated and planned for.

Dr Yoshiyuki Kaneda, of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) will give a talk at the Dublin Institute for Advanced Studies on Monday, 3rd February.

The mega-quake of 11th March 2011 that hit Japan, killed 16,000 people and resulted in €24 billion of damage.

In response, Japanese scientists have just installed a network of some 30 high-tech observatories on the deep ocean floor. Packed with sensors, these stations send real-time information back to shore, monitoring the Earth’s plates as they slip, shift and buckle.

Ireland tsunami threat 

It would be wrong for Irish people to assume that mega-quakes and tsunamis are things that happen in far-flung lands, and have no direct impact on us. The historical and geological record demonstrates that Ireland has been hit by two tsunamis in 1755 and 1761, when buildings were damaged along the south coast.

The tsunami in 1755 was caused by the Great Lisbon Earthquake. A similar quake today could trigger another tsunami endangering the Irish south coast in particular. Ireland is also at the risk of a tsunami from submarine landslides, as happened off Canada in 1929, or a volcanic eruption on the Canary Islands or Caribbean.

Dr Kaneda leads Japan’s Earthquake and Tsunami Research Project for Disaster Prevention at JAMSTEC.

His talk is a joint initiative of the Embassy of Japan in Ireland and the Dublin Institute for Advanced Studies (DIAS), a centre for seismic research which runs the Irish National Seismic Network (INSN), and is open to the public and all interested parties.

As seating capacity is limited, registration is essential at the Embassy of Japan on 01-202 8305 or cultural@ir.mofa.go.jp between 20 and 30 January.

Dr Kaneda is also giving an expert workshop for young researchers on the morning of 3 February.

VIDEOS:

The Great Lisbon Earthquake of 1755 resulted in a tsunami that hit the Irish southwest coast:

JAMSTEC video of the remotely operated vehicle “Hyper dolphin” burying and installing the DONET (Dense Ocean floor Network system for Earthquakes and Tsunamis) observation devices deep under the ocean:

http://www.jamstec.go.jp/donet/e/about/news/20110

Oil & Gas in the offshore: Has Ireland’s ship finally come in?

The prospects for further major finds of oil and gas in the Irish offshore are good [Credit: Providence Resources]

News that a commercially viable oil field has been found off the southwest coast of Ireland made headlines at home and abroad at the end of July and begged the question; how much oil and gas can be exploited in the large Irish offshore?

The potential of the Ballyroe field ( see image on the right) licensed to Providence Resources had been known about for years, but what was significant about the recent news was that the company said the find was far larger than had been previously thought.

The difficult, deep waters off the Irish coast are not the easiest places to search for oil, but with oil prices surging, and a lack of major new finds worldwide, it seems that Ireland’s oil and gas ‘ship’ might finally have come in.

Unlike in times past, exploration companies have the technology and the motivation to exploit Irish hydrocarbon reserves. So, what might they find? We asked Dr Andrew Wheeler, Head of Geology at University College Cork.

LISTEN: Interview with Dr Andrew Wheeler

Broadcast on 09.08.2012 on Science Spinning on 103.2 Dublin City FM

When rocks start ‘talking’: The science of geo-chemical fingerprinting

Geochemistry can get rocks to ‘talk’ about how they were formed, and when (credit: http://www.crsbooks.net)

We have all heard of DNA fingerprinting, where the DNA in a person’s blood is identified, for example, at the scene of a crime, or on a victim, leading to a criminal prosecution.

But, what exactly is a geochemical fingerprint? Well, the same principle applies, but this time it concerns rocks. The geochemistry of a rock can provide information about how it formed, when, and what has happened to it since.

It can also be used for a variety of non-geological purposes, such as, for example, determining where a neo-lithic person lived from the examination of the carbon and oxygen isotopes in their teeth enamel.

This provides clues as to what they ate, and what water they drank.

LISTEN: Interview with Professor Balz Kamber

Broadcast on Science Spinning on 103.2 Dublin City FM on 12-04-2012

‘Fracking’ can end Ireland’s dangerous reliance on imported natural gas

Ireland is dangerously dependent on imports of natural gas. Bringing home-grown gas ashore and retrieving onshore reserves under western and northwestern counties can end this reliance and transform Ireland into a natural gas exporter.

For more, read ‘Think Tank’ article published in The Sunday Times, below, on 11.03.2012

Robert Mallet – the earthquake detective

The first photographs ever taken of the aftermath of an earthquake were taken of the Great Neopolitan Quake of 1857, which destroyed the village of Pertosa, pictured here, and many other towns and villages in southern Italy. The pictures were taken by a Frenchman called Grellier, and commissioned by Irish scientist and Dubliner Robert Mallet who was the first to determine what caused earthquakes such as this one [Credit: Dublin Institute for Advanced Studies].

Listen here to the story of Robert Mallet

First broadcast on East Coast FM in December 2017 as part of the Irish Scientists series produced by Red Hare Media.

The science of seismology, which studies the power and energy unleashed by earthquakes, began life on a south Dublin beach in 1849 with an ingenious experiment carried out by one of Ireland’s greatest scientists. That scientist was Robert Mallett – a Dubliner widely recognized as the ‘father of seismology’. Widely recognised that is, outside Ireland, where he remains largely an unknown figure outside the scientific community.

A true blue Dub you might say, Robert Mallett was born on Capel Street, on the banks of the Liffey, on the 3rd June 1810. His father owned a successful iron foundry business. The legacy of this foundry’s success can still be seen today, on the iron railings around Trinity College, which are inscribed with the name R&J Mallett.

From an incredibly early age, Robert was interested in science, and in particular chemistry. From the age of perhaps two, or three, he had his own small laboratory set up in the family house, where he played with chemicals. Such was Robert’s enthusiasm for spending time in the lab, the story goes, that his parents used to lock him out of the lab in order to punish him for some misdeed.

Later, in his teenage years, he went down the road to TCD to study science. The science course at TCD at that time – the early part of the 19th century – was more like what we would recognise as engineering today – very technical. After his studies were complete he went back to work in the family business. He continued to have a fascination with all things science, and began to conduct experiments on how sound or energy moved through sand and rock.

KILLINEY

In October 1849, aged 39, Robert, and his son John, who was a chemistry student at TCD, decided to carry out a remarkable experiment on Killiney Beach. They wanted to prove that energy moved through sand and rock in waves that could be measured, and they designed a ‘controlled’ experiment to prove this was so.

The two Malletts buried a keg of gunpowder in the ground, and detonated it. They measured the energy wave that traveled through the sand at a distance of half a mile away, with a seismoscope. The experiment worked, and a seismic reading was generated that showed clearly, energy moved through sand in waves.

Robert also worked closely with William Rowan Hamilton, another great Irish scientist and mathematician. William had suggested to Robert that he might apply the laws of physics, as they apply to light, in order to describe how the energy generated by the explosion would pass through sand and rock (for the rock measurements he set up a seismoscope on nearby rocky Dalkey Island, rather than the sandy beach). Robert took William’s advice and Robert’s report on his experiment became the foundation of modern seismology.

ITALY

Robert is not well known in Ireland, except amongst the small community of geologists and earth scientists that would appreciate his importance in the advancement of our understanding of earthquakes.

However, in southern Italy Robert is well known, due to his role in studying the after affects of the ‘Great Neapolitan Earthquake of 1857’. This earthquake – which was the third biggest in recorded history at the time – struck in deadly fashion on the 16th December, and killed in the region of 20,000 people.

Robert reacted quickly and wanted to go to the earthquake zone and record the devastation, using the new technology of photography. Two powerful friends, Charles Lyle, a famous English geologist, and Charles Darwin, helped Robert to get a grant from the Royal Society to travel to Italy and carry out this work.

Robert arrived in Italy and worked right through Christmas and into the New Year, diligently recording the devastation along with a French photographer. This was the first time ever that photography had been used to take images of the after affects of an earthquake. It was a revolutionary approach at the time.

Robert’s report entitled ‘Great Neapolitan Earthquake of 1857: The First Principles of Observational Seismology’ was published by the Royal Society in 1862. It remains as ‘seminal research’ into seismic hazard and seismic risk, said Tom Blake, experimental officer in the geophysics section of the Dublin Institute for Advanced Studies (DIAS).

The bicentenary of the birth of Robert Mallett was held in 2010 and the DIAS and the Royal Dublin Society had joint celebrations. This was done, said Tom Blake at the time, “so that, at least, once and for all, Irish people will understand, and know, that the father of controlled-source seismology is an Irishman – Robert Mallett”.

SEISMIC SCIENTISTS

In 132 AD, in China, a man called Zhang Heng, invented the world’s first seismometer – an instrument capable of measuring ground movements due to earthquakes. The machine Zhang invented enabled him to determine the direction and occurrence of the epicenter of an earthquake. For example, his device could pinpoint an earthquake occurring at a location 400 miles away, long before horse-bound messengers could bring the Emperor the bad news. This enabled the Emperor to quickly dispatch help to the afflicted area.

The west was far behind China in seismic studies. As late as 1755, more than 1,600 years after China had invented the first seismometer, people believed that the Great Lisbon Earthquake of that year, which killed 70,000 with an accompanying tsunami, was God’s punishment for the sins of mankind.

Not everyone in the west believed in the ‘God’ explanation for earthquakes in the 18th century. One of those was John Mitchell, a clergyman, and academic at Cambridge University. Mitchell proposed that earthquakes caused by energy waves originated below ground. At the time, his theory was largely ignored.

In 1795, Ascanio Filomarino devised a seismograph similar to the one Zhang had invented centuries before. It had a part that would stay stationary while the rest of the instrument would shake when an earthquake was occurring, and ring bells and set off a clock. Poor Ascanio was murdered on Mt Vesuvius by an angry mob that didn’t like his work. They also burned his workshop and destroyed his seismograph.

Another early ‘seismograph’ was developed by Luigi Palmieri, in 1855. Palmieri was the director of an observatory near Vesuvius. An instrument, designed by Palmieri, could measure small tremblings in the ground around Vesuvius, and recorded such movements on a paper strip – like later seismographs.

The big contribution of Robert Mallett to this emerging field came in 1857 when he examined the damage caused by the earthquake in Italy of that year. He generated isoseismal maps, which displayed contours of damage intensity. He also published a world map that revealed the clustering of earthquake incidences in specific locations around the planet. Thus, Mallett, was the first to see the ‘big picture’ with regard to earthquakes.

First published in the September-October 2009 edition of Science Spin

The Irish Gold Frenzy

Famously, there have been gold rushes in California, Alaska, Australia and even Brazil. But, Ireland also had its own gold rush, in 1795, just before the United Irishman rebellion, following the chance discovery of a nugget in County Wicklow.

Peader McArdle, the recently retired director of the Geological Survey of Ireland, has written  ‘Gold Frenzy’ a book which charts the many aspects of the gold rush story in Ireland, in the years before rebellion set Wicklow’s  heather blazing.
LISTEN:  The Wicklow ‘Gold Frenzy’ —Peader McArdle, author of Gold Frenzy, interviewed on Science Spinning on 103.2 Dublin City FM (broadcast 27th October 2011).
This book is as much about geology as it is about great characters, the use of Ireland’s national resources, and the role of powerful politicians such as Charles Stewart Parnell, whose lands in Avoca lay in the heart of Wicklow gold.
Gold Frenzy is highly recommended and  is available from Dubray bookshop in Bray, the Geological Survey of Ireland, and other bookshops. It can also be ordered on line from the Science Spin website store.