Saturday, October 18, 2014

Climate change: Sea levels steady for 6,000 years before rapid rise in past 150 years, study reveals

Australian National University (ANU) Professor Kurt Lambeck led the research into sea levels.

By Carl Smith

Sea levels remained steady for thousands of years before recent rapid rises, a study led by the Australian National University shows.

The study looked at the fluctuation of ocean levels over the past 35,000 years, based on ice volume changes around the world.

The researchers have described the study as the most comprehensive paper of its kind looking at the period.

ANU's Professor Kurt Lambeck said sea levels were oscillating by no more than 20 centimetres over several millennia.

"In the last 6,000 years before the modern onset of sea level rise, the sea level has been quite stable," he said.

"We see no evidence for oscillations in sea level greater than say plus or minus 25 or 30 centimetres, on timescales of 100 years or longer - there's just no evidence for that."

But he said there has been a rapid upward trend accompanying global industrialisation.

"For the last 150 years we've been seeing this increase, this rising sea level, at a rate of a few milimetres per year and in our older records we do not see similar behaviour," he said.

He said comparing the historical data with recent data from tidal gauges shows an increasing rate of sea level rise in recent times.

"We really have established the background signal from say 150 years ago to 6,000 years ago, and we can compare that with the tide gauge record," Professor Lambeck said.

"What we see in the tide gauges we don't see in the past record, so there's something going on today that wasn't going on before.

"I think that is clearly the impact of rising temperatures."

He said increasing temperatures have been documented to have clear effects on sea levels.

"Both because the thermal expansion of the oceans, the oceans are warming up, that's reasonably well documented, and it's the melting primarily up until now of the mountain glacier systems, so those two contributions are probably the most important part to what's happened in the last 100 years," Professor Lambeck said.

The study will create a comprehensive historical background for sea levels so researchers can better monitor current trends.

Recent sea level rise 'unusual'


Monday, October 6, 2014

From Indonesia To Turkey New Archaeological Discoveries Uncover The Mysteries Of A Lost Civilisation


Artist's impression of Gunung Padang as it would have looked in antiquity by and courtesy of architect Pon S Purajatnika.

By Graham Hancock

"Everything we've been taught about the origins of civilization may be wrong," says Danny Natawidjaja, PhD, senior geologist with the Research Centre for Geotechnology at the Indonesian Institute of Sciences. "Old stories about Atlantis and other a great lost civilizations of prehistory, long dismissed as myths by archaeologists, look set to be proved true."

I'm climbing with Dr Natawidjaja up the steep slope of a 300-ft high step-pyramid set amidst a magical landscape of volcanoes, mountains and jungles interspersed with paddy fields and tea plantations a hundred miles from the city of Bandung in West Java, Indonesia.

The pyramid has been known to archaeology since 1914 when megalithic structures formed from blocks of columnar basalt were found scattered amongst the dense trees and undergrowth that then covered its summit. Local people held the site to be sacred and called it Gunung Padang, the name it still goes by today, which means "Mountain of Light", or "Mountain of Enlightenment", in the local Sundanese language. The summit, where the megaliths were found arranged across five terraces had been used as a place of meditation and retreat since time immemorial, archaeologists were told, and again this remains true today.

However neither the archaeologists, nor apparently the locals realized the pyramid was a pyramid. It was believed to be a natural hill, somewhat modified by human activity, until Natawidjaja and his team began a geological survey here in 2011. By then the summit had long since been cleared and the megalithic terraces recognized to be ancient and man-made, but no radiocarbon dating was ever done and the previously accepted age of the site - about 1,500 to 2,500 BC -- was based on guesswork rather than on excavations.

The first scientific radiocarbon dating was done by Natawidjaja himself on soils underlying the megaliths at or near the surface. The dates produced - around 500 to 1,500 BC - were very close to the archaeological guesswork and caused no controversy. However a surprise was in store as Natawidjaja and his team extended their investigation using tubular drills that brought up cores of earth and stone from much deeper levels.

First the drill cores contained evidence - fragments of columnar basalt - that man-made megalithic structures lay far beneath the surface. Secondly the organic materials brought up in the drill cores began to yield older and older dates - 3,000 BC to 5,000 BC, then 9,600 BC as the drills bit deeper, then around 11,000 BC, then, 15,000 BC and finally at depths of 90 feet and more an astonishing sequence of dates of 20,000 BC to 22,000 BC and earlier.

"This was not at all what my colleagues in the world of archaeology expected or wanted to hear" says Natawidjaja, who earned his PhD at Cal Tech in the United States and who, it becomes apparent, regards archaeology as a thoroughly unscientific discipline.

The problem is that those dates from 9,600 BC and earlier belong to the period that archaeologists call the "Upper Palaeolithic" and take us back deep into the last Ice Age when Indonesia was not a series of islands as it is today but was part of a vast southeast Asian continent dubbed "Sundaland" by geologists.

Sea level was 400 feet lower then because huge ice caps two miles deep covered most of Europe and North America. But as the ice caps began to melt all the water stored in them returned to the oceans and sea-level rose, submerging many parts of the world where humans had previously lived. Thus Britain was joined to Europe during the Ice Age (there was no English Channel or North Sea).

Likewise there was no Red Sea, no Persian Gulf, Sri Lanka was joined to southern India, Siberia was joined to Alaska, Australia was joined to New Guinea - and so on and so forth. It was during this epoch of sea-level rise, sometimes slow and continuous, sometimes rapid and cataclysmic, that the Ice Age continent of Sundaland was submerged with only the Malaysian Peninsula and the Indonesian islands as we know them today high enough to remain above water.

The established archaeological view of the state of human civilization until the end of the last Ice Age about 9,600 BC was that our ancestors were primitive hunter gatherers incapable of any form of civilization or architectural feats. In the following millennia settled agriculture was very gradually developed and perfected. Around 4,000 BC the increasing sophistication of economic and social structures, and growing organizational abilities, made possible the creation of the earliest megalithic sites (such as Gigantija on the Maltese island of Gozo for example) while the first true cities emerged around 3500 BC in Mesopotamia and soon afterwards in Egypt. In the British Isles Callanish in the Outer Hebrides and Avebury in southwest England, both dated to around 3,000 BC, are the oldest examples of true megalithic sites. The megalithic phase of Stonehenge is thought to have begun around 2,400 BC and to have continued to around 1,800 BC.

Within this well worked out and long-established chronology there is no place for any prehistoric civilization such as Atlantis. But interestingly the Greek philosopher Plato, whose dialogue of Timias and Critias contains the earliest surviving mention of the fabled sunken kingdom, dates the catastrophic destruction and submergence of Atlantis by floods and earthquakes to "9,000 years before the time of Solon" - i.e. to 9,600 BC, the end of the last Ice Age. Since the Greeks had no access to modern scientific knowledge about the Ice Age and its rapidly rising sea levels (often accompanied by cataclysmic earthquakes as the weight of the melting ice caps was removed from the continental landmasses) the date Plato gives is, to say the least, an uncanny coincidence.

In Danny Natawidjaja's view, however, it is no coincidence at all. His research at Gunung Padang has convinced him that Plato was right about the existence of a high civilization in the depths of the last Ice Age - a civilization that was indeed brought to a cataclysmic end involving floods and earthquakes in an epoch of great global instability between 10,900 BC and 9,600 BC.

This epoch, which geologists call the "Younger Dryas" has long been recognized as mysterious and tumultuous. In 10,900 BC, when it began, the earth had been emerging from the Ice Age for roughly 10,000 years, global temperatures were rising steadily and the ice caps were melting. Then there was a sudden dramatic return to colder conditions - even colder than at the peak of the Ice Age 21,000 years ago. This short, sharp deep freeze lasted for 1,300 years until 9,600 BC when the warming trend resumed, global temperatures shot up again and the remaining ice caps melted very suddenly dumping all the water they contained into the oceans.

"It is difficult," Natawidjaja says, "for us to imagine what life on earth must have been like during the Younger Dryas. It was a truly cataclysmic period of immense climate instability and terrible, indeed terrifying, global conditions. It's not surprising that many large animal species, such as the mammoths, went extinct during this precise time and of course it had huge effects on our ancestors, not just those 'primitive' hunter gatherers the archaeologists speak of but also, I believe, a high civilization that was wiped from the historical record by the upheavals of the Younger Dryas."

What has brought Natawidjaja to this radical view is the evidence he and his team have uncovered at Gunung Padang. When their drill cores began to yield very ancient carbon dates from clays filling the gaps between worked stones they expanded their investigation using geophysical equipment - ground penetrating radar, seismic tomography and electrical resistivity - to get a picture of what lay under the ground. The results were stunning, showing layers of massive construction using the same megalithic elements of columnar basalt that are found on the surface but with courses of huge basaltic rocks beneath them extending down to 100 feet and more beneath the surface. At those depths the carbon dates indicate that the megaliths were put in place more than 10,000 years ago and in some cases as far back as 24,000 years ago.

Columnar basalt does form naturally - the famous Giant's Causeway in Northern Ireland is an example - but at Gunung Padang it has been used as a building material and is laid out in a form never found in nature.

"The geophysical evidence is unambiguous," Natawidjaja says. "Gunung Padang is not a natural hill but a man-made pyramid and the origins of construction here go back long before the end of the last Ice Age. Since the work is massive even at the deepest levels, and bears witness to the kinds of sophisticated construction skills that were deployed to build the pyramids of Egypt or the largest megalithic sites of Europe, I can only conclude that we're looking at the work of a lost civilization and a fairly advanced one."

"The archaeologists won't like that," I point out.

"They don't!" Natawidjaja agrees with a rueful smile. "I've already got myself into a lot of hot water with this. My case is a solid one, based on good scientific evidence, but it's not an easy one. I'm up against deeply entrenched beliefs."

The next step will be a full-scale archaeological excavation. "We have to excavate in order to interrogate our remote sensing data and our carbon dating sequences and either to confirm or deny what we believe we've found here," says Natawidjaja, "but unfortunately there's a lot of obstacles in our way."

When I ask what he means by obstacles he replies that some senior Indonesian archaeologists are lobbying the government in Jakarta to prevent him from doing any further work at Gunung Padang on the grounds that they "know" the site is less than 5,000 years old and see no justification for disturbing it.

"I don't deny that the megaliths at the surface are less than 5,000 years old," Natawidjaja hastens to add, "but I suggest they were put here because Gunung Padang has been recognized as a sacred place since time immemorial. It's the deepest layers of the structure at between 12,000 and more than 20,000 years old that are the most important. They have potentially revolutionary implications for our understanding of history and I think it's vital that we be allowed to investigate them properly."

Gunung Padang is not the only ancient site that raises huge question marks over the story archaeologists tell us about our past. On the other side of the world, in southeastern Turkey, another man-made hill has been excavated during the past decade, this time by Professor Klaus Schmidt of the German Archaeological Institute. The site, called Gobekli Tepe (which means "Potbellied Hill" in the local Kurdish language) consists of a series of immense megalithic stone circles on the scale of Stonehenge and was deliberately buried (creating the appearance of a hill) around 8,000 BC by the mysterious ancient people who made it. The circles themselves date back to 9,600 BC, however, with the oldest work being the best. At least twenty further circles on a similar scale, identified by ground penetrating radar, are still deeply buried. Some of these, Klaus Schmidt told me when I visited Gobekli Tepe in September 2013, are likely to be much older than those already excavated.

At 7,000 or more years older than Stonehenge the megaliths of Gobekli Tepe, like the deeply buried megaliths of Gunung Padang mean that the timeline of history taught in our schools and universities for the best part of the last hundred years can no longer stand. It is beginning to look as though civilization, as I argued in my controversial 1995 bestseller Fingerprints of the Gods, is indeed much older and much more mysterious than we thought.

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Monday, August 11, 2014

Mystery of giant holes in Siberia



Huge holes have been discovered in a Siberian region nicknamed "the end of the world," reports the 'Siberian Times.' First a 260-foot-wide crater caught the world's attention in early July, and now researchers and reindeer herders have uncovered two more: one with a diameter of around 50 feet, and another — which nearly swallowed the herders who stumbled across it — with a diameter of only about 13 feet but an estimated depth of up to 328 feet, 'Gizmodo' reports.


This frame grab made on July 16, 2014, shows a crater discovered recently in the Yamal Peninsula in Yamalo-Nenets Autonomous Okrug, Russia.

Huge, mysterious gaping holes in Northern Siberia may not be such a mystery anymore. One scientist has pinned down a cause and, spoiler alert, it's not aliens or weapons testing, as had been theorized.
The first hole discovered in the Yamal Peninsula, which is 260 feet wide, is likely a sinkhole caused by melting ice or permafrost, University of Alaska geophysicist Vladimir Romanovsky tells LiveScience.

But rather than swallowing the earth as it opened up, he speculates, the hole "actually erupted outside," tossing dirt around the rim. (One caveat: Romanovsky hasn't seen the holes himself, but he has spoken to Russian colleagues who have, notes PRI.)

He suspects natural gas caused pressure to build as the water collected in an underground cavity, and the dirt—which is reportedly piled more than 3 feet high around the edge of the crater — was eventually expelled.

Plants around the crater suggests the hole is several years old, but closer inspection is needed to determine the exact age. Romanovsky thinks climate change played a role, which means "we will probably see this happen more often now," he says. But questions remain, notes LiveScience: Where did the natural gas come from, and why is the hole so even and round?

Friday, August 8, 2014

Early Earth could have been habitable


Hell on Earth: Despite being bombarded by 1000-kilometre wide asteroids, the environment of Earth could have been suitable for life, say researchers (Simone Marchi )

Stuart Gary
ABC


Isolated pockets of liquid water may have existed on the infant Earth even while it was being smashed by giant asteroids that boiled the oceans and created vast seas of magma, a new study suggests.

This means there could have been habitable regions on the Earth during its violent early period, say the authors in today's issue of the journal Nature.

But, they add, any life emerging during Earth's first half billion years would need to have been resistant to extreme conditions, and capable of spreading from the few stable niches existing at that time.

The constant mixing and burial of the Earth's crust by the unrelenting bombardment of asteroids, comets and meteors, during this Hadean epoch, means the geological history of this time -- and whether life existed then -- is poorly understood.

Dr Simone Marchi of the Southwest Research Institute, in Boulder Colorado, and colleagues, have developed a computer model that provides the most detailed picture yet of the Hadean epoch.
Some simulations show up to four large impacts involving 1000-kilometre wide asteroids capable of causing global sterilisation of any life existing at the time.

The simulations also found up to seven asteroids over 500 kilometres wide would have collided with the Earth, each capable of causing global ocean vaporisation, producing a steam atmosphere, and magma oceans, with the most recent occurring four billion years ago.

The researchers found every major part of the Earth would have been affected at one point or another.
Despite all this, the researchers say, there is evidence that there could have been habitable environments at the time.

"We found that the magma oceans were likely to be regional events, so at any given time there were some locations that were calm," says Marchi.

"That means liquid water could have existed in one place or another throughout the 500 million years of the Hadean period."

Marchi says the bombardment by 1000-kilometre wide asteroids would have completely wiped out any life existing at the time and, if that was the case, then life must have started over again after those large collisions.

Moon craters

Marchi and colleagues found the peak bombardment of the early Earth occurred soon after the formation of the Moon and gradually tapered off until the simulation ended 3.5 billion years ago, by which time the number of impacts was negligible.

They determined Earth's early impact history by examining the heavily cratered surface of the Moon which provides a record of the number of impact events and the size of the objects that caused them.

"The moon's surface is on average much older than the surface of the Earth, because the Moon is basically a dead body in which geological evolution is reduced to a minimal level," says Marchi.

"We found the populations of different sized impactors hitting the Moon is very similar to the size distribution of asteroids in the main asteroid belt today. This was also true for Mercury and the oldest surfaces on Mars."

Tuesday, July 8, 2014

Fossil of biggest-known flying seabird found


The bird's wings were twice as long as the biggest modern-day seabird, the royal albatross, say scientists (Source: Liz Bradford)

AFP

Fossilised bird bones uncovered in the US represent the largest flying bird in history, with a wingspan of 6.4 metres, say researchers.

Their findings, published this week in the Proceedings of the National Academy of Sciences, show the bird's wings were twice as long as the biggest modern-day seabird, the royal albatross.

Coupled with its long beak and sharp bony teeth, Pelagornis sandersi's enormous wings likely helped the bird master long periods of gliding over water in search of seafood some 25 to 28 million years ago.

However, the bird might have needed some help getting airborne, given that its wings were simply too long to flap easily from the ground.

Scientists believe it may have made a running start downhill, or used air gusts - much like a hang glider - to make its way aloft.

Once in the air, the bird could probably soar for miles without ever flapping its wings, says study author Dan Ksepka of the National Evolutionary Synthesis Center in Durham, North Carolina.
"That's important in the ocean, where food is patchy," he says.

P. sandersi lived after the dinosaurs became extinct but before the first humans are known to have inhabited North America.

Excavation

The bird's wing and leg bones along with its complete skull were first discovered in 1983 near Charleston, South Carolina, during excavation work for a new international airport.

"The upper wing bone alone was longer than my arm," says Ksepka, recalling that a backhoe was called in to help unearth the bones.

The bone measurements suggest that the bird's wingspan was between 6.06 and 7.38 metres, according to the researchers.

The previous size record holder was an extinct, 6-million-year-old bird found in Argentina, named Argentavis magnificens. Its wingspan was estimated at about 6.4 metres.

The fossils of the P. sandersi shed light on the flying ability of a remarkable bird, but also raise new questions about the group of bony toothed seabirds known as pelagornithids, which disappeared some 2.5 million years ago.

These ancient birds were "remarkably efficient fliers" that were found across all seven continents, making "the cause of their ultimate extinction all of the more mysterious," say Ksepka and colleauges.

Saturday, May 3, 2014

'Earth-like' planet Kepler-186f discovered by NASA scientists


Scientists have found an Earth-sized world orbiting in a life-friendly zone around a distant star for the first time.

The discovery, announced on Thursday, is the closest scientists have come so far to finding a true Earth twin.

The star, known as Kepler-186 and located about 500 light years away in the constellation Cygnus, is smaller and redder than the sun.

The star's outermost planet, designated Kepler-186f, receives about one-third the radiation from its parent star as Earth gets from the sun, meaning that high noon on this world would be roughly akin to Earth an hour before sunset, said astronomer Thomas Barclay from NASA's Ames Research Centre.
The planet is the right distance from its host star for water - if any exists - to be liquid on the surface, a condition that scientists suspect is necessary for life.

"This planet is an Earth cousin, not an Earth twin," said Mr Barclay, who is among a team of scientists reporting on the discovery in the journal Science this week.

NASA launched its Kepler space telescope in 2009 to search about 150,000 target stars for signs of any planets passing by, or transiting, relative to the telescope's point of view.

Analysis of archived Kepler data continues. From Kepler's observational perch, a planet about the size and location of Earth orbiting a sun-like star would blot out only about 80 to 100 photons out of every million as it transits.

The pattern is repeated every 365 days and at least three transits would be needed to rule out other possibilities, so the search takes time.

"It's very challenging to find Earth analogs," Mr Barclay said.

"Most candidates don't pan out, but things change as we get more measurements."

Scientists do not know anything about the atmosphere of Kepler-186f, but it will be a target for future telescopes that can scan for telltale chemicals that may be linked to life.

"This planet is in the habitable zone, but that's doesn't mean it is habitable," Mr Barclay said.
So far, scientists have found nearly 1,800 planets beyond the solar system.

"The past year has seen a lot of progress in the search for Earth-like planets," astronomer David Charbonneau from the Harvard-Smithsonian Centre for Astrophysics wrote in an email.

"Kepler-168f is significant because it is the first exoplanet that is the same temperature and is (almost) the same size as Earth.

"For me the impact is to prove that yes, such planets really do exist. Now we can point to a star and say: 'There lies an Earth-like planet'."

Reuters

Monday, April 28, 2014

Jerusalem: 2,700 year old inscription discovered


In Antiquities Authority excavations in the city of David clay crockery dated to the 8th and 7th centuries BC were discovered. One is possibly inscribed with the name a biblical character.

Rina Feingold

In excavations performed by the Antiquities Authority in the area of the Gihon Spring a layer filled with exciting findings was uncovered – in which are thousands of broken pieces of clay crockery, clay candles and figurines. The experts estimate that they are from the end of the first temple period.

One of the most significant discoveries is a clay bowl with an incomplete inscription on it. According to estimations, the name closest to the partial one found on the bowl is Zechariah Ben Benayah.

Due to the lack of some of the letters, the archeologists can’t determine with certainty whether the object belong to the biblical character mentioned in Chronicles. 
 
Antiquities Authority archeologists Joe Uziel and Nachshon Zanton, who discovered the bowl, date the letters inscribed in the clay to the 7-8th century BC, and attribute the bowl to the time between the monarchy of Hezekiah to the destruction of Jerusalem in the days of king Zedekiah.

The purpose of the inscription is not clear, but the archeologists claim that the bowl could have contained an offering, and it is probable that it carried the name of the he who was offering, or he who was receiving the offering.