jump to navigation

Tsunami readiness tests for coastlines March 14, 2008

Posted by grhomeboy in Archaeology Greece, Environment, Nature, Science.
Tags: , , , , , ,
comments closed

Greece should start holding tsunami readiness tests in the southern Aegean and southern Ionian, according to Greek and Italian scientists who are creating an early warning system for the Mediterranean.

The system, being developed under the auspices of UNESCO, should be in place by the end of the year and fully functional by 2011, according to Stefano Tinti of the University of Bologna.

Already three seismograph systems are in operation, said Gerasimos Papadopoulos of the Athens Geodynmaic Institute, adding that six sea-level gauges will be set up, two in Crete and four in the Ionian.

Particular care must be taken during the tourist season, the experts said. “Local authorities will be trained in readiness exercises,” Tinti said. “Evacuating the beaches of 10 Greek islands in summer cannot be taken lightly,” he added.

UPDATED > 15 March 2008 >>> Tsunami that devastated the ancient world could return

“The sea was driven back, and its waters flowed away to such an extent that the deep sea bed was laid bare and many kinds of sea creatures could be seen,” wrote Roman historian Ammianus Marcellus, awed at a tsunami that struck the then-thriving port of Alexandria in 365 AD.

“Huge masses of water flowed back when least expected, and now overwhelmed and killed many thousands of people… Some great ships were hurled by the fury of the waves onto the rooftops, and others were thrown up to two miles (three kilometres) from the shore.”

Ancient documents show the great waves of July 21, 365 AD claimed lives from Greece, Sicily and Alexandria in Egypt to modern-day Dubrovnik in the Adriatic.

Swamped by sea water, rich Nile delta farmland was abandoned and hilltop towns became ghost-like, inhabited only by hermits. The tsunami was generated by a massive quake that occurred under the western tip of the Greek island of Crete, experts believe. Until now, the main thinking has been that this quake, as in the Indian Ocean tsunami of December 26, 2004, occurred in a so-called subduction zone.

A subduction zone is where two of the Earth’s plates meet. One plate rides over another plate which is gliding downward at an angle into the planet’s mantle. Subduction zones usually have measurable creep, of say a few centimetres (inches) a year. But as the rock becomes brittle and deformed at greater depths, these zones can also deliver titanic quakes, displacing so much land that, when the slippage occurs on the ocean floor, a killer wave is generated.

The 365 AD quake occurred at a point on the 500-kilometre (300-mile) long Hellenic subduction zone, which snakes along the Mediterranean floor in a semi-circle from southwestern Turkey to western Greece.

Researchers in Britain have taken a fresh look at this event and have come up with some worrying news. University of Cambridge professor Beth Shaw carried out a computer simulation of the quake, based especially on fieldwork in Crete where the push forced up land by as much as 10 metres (32.5 feet).

They estimate the quake to have been 8.3-8.5 magnitude and that its land displacement, of 20 metres (65 feet) on average, puts it in the same category as the 9.3 temblor that occurred off Sumatra in 2004. They conclude the slippage occurred along 100 kilometres (about 60 miles) on a previously unidentified fault that lies close to the surface, just above the subduction zone.

The quake happened at a depth of around 45 kilometres (30 miles), around 30 kilometres (20 miles) closer to the surface than would have been likely if the slip had occurred on the subduction fault itself. After the 365 AD quake, the fault is likely to remain quiet for around 5,000 years.

But if the tectonic structure along the rest of the Hellenic subduction zone is similar, a tsunami-generating quake could strike the eastern Mediterranean in roughly 800 years, the scientists estimate. The last tsunami to hit the eastern Mediterranean occurred on August 8, 1303. According to research published in 2006, a quake off Crete of about 7.8 magnitude hit Alexandria 40 minutes later with a wave nine metres (29.25 feet) high.

“That there has been only one other such event… in the past 1,650 years should focus our attention on the modern-day tsunami hazard in the eastern Mediterranean,” the new study, published in the journal Nature Geoscience, warns. “Repetition of such an event would have catastrophic consequences for today’s densely-populated Mediterranean coastal regions.”

The UN Educational, Scientific and Cultural Organisation (UNESCO) is setting up a tsunami alert system for the Mediterranean as part of a global network established after the 2004 Indian Ocean disaster.

Advertisement

Greek scientists blaze way in solving Internet questions November 1, 2007

Posted by grhomeboy in Internet & Web, Science, Technology.
Tags: , , ,
comments closed

Experts at i-sieve are developing content-filtering technology > Researchers Giorgos Paliouras, Vangelis Karkaletsis, Thomas Biziliotis, Timos Kouloumbis, Constantinos Spyropoulos and Costas Handrinos.

In a tiny office with just a couple of computers and a coffee machine, the firm known as i-sieve, set up in 2004 by a group of researchers at the National Center for Scientific Research (NCSR) called “Democritos,” the fate of a Hollywood director has been decided, a Mexican advertising campaign for a deodorant has been changed and the discovery made that Adidas wasted 200 million dollars at the World Cup soccer tournament in Germany.

The firm, i-sieve technologies, is a Democritos spin-off company whose researchers have developed content-filtering technology to tune into the opinions of millions of people from all corners of the earth who use the Internet for everything from products and services to candidates for the leadership of political party.

The job assigned to i-sieve is to use artificial intelligence to analyze the content of websites. These online media analysis methods are based on an innovative system of thematically organizing Internet content developed at the Software and Knowledge Engineering Laboratory at Democritos.

“In effect, this is an algorithm which we train to search the Web for what interests us and to classify it,” explained Costas Handrinos, the Director of i-sieve. A typical project is their input to MedIEQ, which reviews and controls the accredited or filtered medical websites.

“About 80 percent of Internet users around the world visit medical sites and 40 percent of these people say the information they obtain affects their final decisions regarding their treatment,” said Evangelos Karkaletsis, one of the co-founders of i-sieve. “As a result, the information they get from the Internet is important; someone has to guarantee the reliability of these pages. The data that is valid now could, in the next few seconds, change as the content of the site changes. This is where we come in. We have developed specialized engines to search for the medical content of websites on the basis of specifications set by doctors. The objective is cooperation between search engines so that the results are linked to the credibility of a site.”

The company’s biggest customers are foreign advertising firms, mostly members of the multinational Interpublic Group, that interpret prevailing trends among Internet users for corporate clients and advertising campaigns.

“The system can provide a real-time view of various aspects of the Internet, special interest sites, blogs, forums, chat rooms and so on, and pinpoint references of interest to each search and to classify them automatically, for example, positive, negative, neutral,” explained Giorgos Paliouras, a Democritos researcher and co-founder of i-sieve.

It is something like a passive opinion poll, as on these sites users express their views spontaneously and these are monitored by the algorithm.

One job was for a major Hollywood studio. “We investigated trends regarding a top director’s latest film. We found that users blamed him because the film had flopped. There was a very negative buzz about him on the Internet. The data we collected persuaded the studio to stop working with the director.”

Before the World Cup in Germany in 2006, Adidas had spent 200 million dollars for exclusive television advertising, no other firm would be linked to this major sporting event. At that time the ratio of Internet searches on Adidas and Nike was 3:10. When the tournament was over, it was up to 7:10. “Was it worth 200 million dollars? Considering that Nike swept the Internet with just one videoclip of Ronaldinho, without paying even a cent, probably not,” said Thomas Biziliotis, an Internet advertising analyst.

Ancient Elephas Cypriotes and Phanourios Minutis fount in Cyprus October 8, 2007

Posted by grhomeboy in Archaeology Cyprus, Science.
Tags: , , ,
comments closed

Cyprus > once home to the dwarf elephants and pygmy hippos > An excavation in the Famagusta [Ammochostos] district has unearthed animal remains including tiny elephants and hippopotamuses dating back some 250,000 years.

The recent findings in an area close to Ayia Napa revealed the skeletal remains of dwarf elephants (Elephas Cypriotes) and pygmy hippos (Phanourios Minutis) as well as remains of ancient rats and bats. Other remains include fossilised flesh of animals and remains of now extinct birds. Similar remains have also been discovered in other Mediterranean islands such as Sardinia and Crete.

In the past, similar findings from the Epipalaeolithic age were made with the most intriguing remains unearthed in areas close to Pentadaktylos and Xylotymbou. This is the fourth such dig to take place in six years with the first dig taking place in October 2001, the second between May and June 2002 and the third in October 2002.

According to scientists, Cyprus was not settled in the Old Stone Age, which led to the survival of numerous dwarf forms, such as the dwarf elephants and pygmy hippos. These animals are thought to have arrived on the island as a result of being swept out to sea while swimming off the coast of what is now Egypt. During the Epipalaeolithic age, it is believed that Cyprus was far closer to Egypt, with some estimating the distance as no more than 30 kilometres.

The extinction of the pygmy hippos and dwarf elephants has been linked to the earliest arrival of Homo sapiens on the island. Piles of burned bones discovered in the caves of the first humans in Cyprus is further evidence that the first Cypriots may simply have gobbled them up. The caves were discovered on the southern coasts of the island.

The pygmy hippo, which measured 1.5 metres in length and 0.75 metres in height, became extinct between 11,000 and 9,000 years ago. The dwarf elephants were around one metre tall.

The reason behind the dwarfing of many animals in Cyprus came about through the process of insular dwarfism which is caused by gene pools limited to a small environment.
The skeletal remains discovered at the recent dig in Xylotymbou have been sent to the Geology and Paleontology Department, which operates under the wing of the University of Athens.

Greek scientists using art paintings to study climate’s change October 1, 2007

Posted by grhomeboy in Arts Events Greece, Environment, Science.
Tags: , , , ,
comments closed

Greek scientists study art paintings for information about global warming

Scientists at Greece’s National Observatory of Athens are using artists’ renditions of sunsets to glean information about the effects of climate change, The Guardian reports.

The team is looking at 554 works dating from 1500 to 1900 and painted by 181 artists, including Rubens, Rembrandt, Gainsborough, and Hogarth to estimate how much natural pollution was released into the skies following historical volcanic eruptions such as that of Mount Krakatoa in 1883. By studying the colors in skies painted before and after such eruptions, researchers say they can calculate how much material was in the sky at the time.

The scientists are also speaking with the Tate in London about repeating the study with 40 paintings from the 20th century in order to study the effects of pollution on sunsets since the Industrial Revolution.

Satellite pinpoints burnt Greek land September 27, 2007

Posted by grhomeboy in Environment, Greece News, Nature, Science, Technology.
Tags: , , , , , ,
comments closed

Satellite images of the 182,305 hectares of land burnt across Greece by this summer’s fires in the Peloponnese and Mount Parnitha, north of Athens, will help authorities better prepare reforestation plans and anti-flood projects, according to Thessaloniki’s Aristotle University.

The Thessaloniki University has obtained the images of the burnt land from the British satellite DMC that will be handed over to authorities to facilitate delineation of the scorched forests. It is only the second time satellite images will be used to identify burnt areas in the country after the forest fires in Cassandra, northern Greece, last year.

“This system was launched with funding from European programs and has been operating since 2003,” said Ioannis Gitas, lecturer at Thessaloniki’s Aristotle University.

“Its operation is supported by algorithms so that credible statistical data are produced. The analysis of data from satellite images is done with precision of up to 1 meter,” he added.

Climate pledge signed in Athens September 27, 2007

Posted by grhomeboy in Environment, Nature, Science.
Tags: , , , ,
comments closed

A group of 200 Greek and foreign scientists, including the three Nobel Prize winners who discovered the hole in the ozone layer, yesterday signed a declaration calling on governments and industries to take bolder steps to protect the environment and prevent further damage being wreaked by climate change.

«An understanding of the interaction between the ozone layer and climate change is critical to ensure the ozone is protected,» according to the «Athens Declaration.» The pact also called for «the improvement of systems for monitoring the ozone layer, from Earth and space.»

Scientists agreed that fighting climate change was a key prerequisite for protecting the ozone. «It is essentially the same issue but we need new approaches and new research,» the President of the International Ozone Commission, Ivar Isaksen, said.

Scientists expressed fears of cuts in the funding for research. «We have seen a trend of cancellations of research programs for the stratosphere, both by the EU and the USA,» Professor William M. Cirillo of NASA said.

The Athens Declaration was signed on the 20th anniversary of the Montreal Protocol, internationally recognized for having saved the ozone layer. But the President of Athens’ National Observatory, Christos Zerefos, warned against complacency. «We have had successes but the battle is not over,» he said.

An ongoing study of the ozone layer should be conducted alongside intensive research into climate change, Zerefos said. He also stressed the importance of businesses taking a more responsible stance toward the environment. «It is the obligation of the industrial sector to take urgent action in this direction,» he said.

The geography of surface water pollution in Greece September 24, 2007

Posted by grhomeboy in Environment, Nature, Science.
Tags: , , , ,
comments closed

Non-coastal Epirus has cleanest lakes and rivers in Europe > The waters of the Pindus ranges are as clear as they look. Water quality in Epirus, excepting its coastal areas, is exceptionally good.

  Pictured is the Aspropotamos (White) River.

The quality of lake and river water in Greece varies widely. Typically, bodies of water that have been subject to human activity, chiefly in the form of industry and agriculture, but also in the form of urban waste, have poor quality water. By contrast, surface waters in the Pindus region and throughout Epirus, apart from its coast, are considered to be the cleanest in Europe.

The basic cause of pollution of surface water “is not the lack of legislation so much as the lack of monitoring compliance with it,” George Zalidis, director of the Applied Soil Science laboratory at Aristotle University in Thessaloniki, said. Moreover, local government, which is responsible for inspections, is vulnerable to pressure from local communities.

Hence there are cases such as that of Lake Koroneia, where once again scores of dead birds were found in the past few days. That lake receives unprocessed urban effluent from the Municipality of Langada, around 10,000 inhabitants, because the waste processing plant installed 10 years ago is not in operation.

Applying the European Union directive on water quality (2000/60), Aristotle University studied five physical and chemical parameters to measure water quality in rivers and lakes, using data collected by the Agriculture Ministry.

The first parameter they examined was the electrical conductivity of the water, which depends on the degree of salinity. As Zalidis explained, salinity comes from sea water entering bodies of fresh water (in estuaries, for example), but also from human activity. In Koroneia, large amounts of salt used by dyeing firms enter the lake. A more serious problem affects water in eastern and central Macedonia, due to pollutants from both Greece and neighboring countries.

The second parameter examined was the increase in the water’s pH, which is a common phenomenon in Koroneia. The rise in pH stems from substances that enter the lake as a result of industrial activity. “Fish and other organisms cannot tolerate these sudden changes and they die,” said Zalidis. The same applies to the third parameter, the concentration of dissolved oxygen. When the oxygen in water falls below a certain level, life cannot survive in the water and mass deaths ensue.

The levels of nitrates and phosphorus in the water rise as a result of farming and the use of fertilizers, as well as due to industrial outflow which overloads lakes and rivers with organic substances. In terms of geography, the highest levels of nitrates appear in rivers such as the Nestos, Evros and Axios that also cross other states.

High concentrations also occur in areas with intensive farming, such as the plain of Thessaly with the Pineios river, the Serres plain (Strymonas) and Appollonia (Axios). High levels of phosphorus appear in the Evros and Axios rivers, and the lakes of Petres, Heimaitidia, Zazari, Koronia and Ioannina.