A powerful earthquake in Alaska sent towering waves up to 30 feet (9 meters) tall crashing down on Hawaii about 500 years ago, leaving behind fragments of coral, mollusk shells and coarse beach sand in a sinkhole located on the island of Kauai, new research finds.

The quake, likely a magnitude 9.0, sent the mighty waves toward Hawaii sometime between 1425 and 1665, the study found. It's possible that another large Alaskan earthquake could trigger a comparable tsunami on Hawaii's shores in the future, experts said.

The tsunami was at least three times the size of the damaging 1946 tsunami, which was driven by an 8.6-magnitude earthquake off the Aleutian Islands. Mammoth tsunamis, like the one described in the study, are rare, and likely happen once every thousand years.

There's a 0.1 percent chance it could happen in any given year, the same probability that northeastern Japan had for the 9.0-magnitude 2011 Tohoku earthquake and related tsunami, said Gerald Fryer, a geophysicist at the pacific Tsunami Warning Center in Ewa Beach, Hawaii, who was not involved in the study.

Results of the study have already prompted Honolulu officials to revise their tsunami evacuation maps, Fryer said. The new maps, which will affect nearly 1 million people who live in Honolulu County, would include more than twice the area of evacuation in some areas, Fryer said in a statement. County officials hope to distribute the new maps by the end of 2014, Fryer said.

Tutankhamun's beautiful golden mask, the embodiment of a man secure in his power, has been flattering the pharaoh for many centuries, according to the most detailed image yet of the teenage king's face and body.

In the flesh, King Tut had a club foot, a pronounced overbite and girlish hips, says a "virtual autopsy" built using more than 2,000 computerized tomography (CT) scans of the pharaoh's body.

Built for the BBC documentary, Tutankhamun: the Truth Uncovered, the shocking 3-D computer model could shed new light on the death of the boy pharaoh at the age of 19.

Previous theories suggested King Tut may have died as a result of a chariot accident, but the virtual reconstruction showed a different scenario.

"It was important to look at his ability to ride on a chariot and we concluded it would not be possible for him, especially with his partially clubbed foot, as he was unable to stand unaided," Albert Zink, head of the Institute for Mummies and Icemen in Italy, told the U.K. daily The Independent.

On October 19th, an inspector sent north from London to Sunderland reported a long-awaited arrival: the first British case of cholera. It was 1831 and as part of a second pandemic cholera had again progressed from its Bengal heartland through Europe, before reaching the Baltic ports. It was only a matter of time.

The British public, informed by newspaper reports, were acquainted with the symptoms: profuse watery diarrhoea, severe abdominal pain and often death within a matter of hours. In advance of its arrival in Russia thousands fled from the cities. In Poland it was killing one in two victims. And unlike today, where oral rehydration solution can prevent dehydration and shock, there was no effective treatment.

Cholera was (and is) caused by vibrio cholerae bacteria and spread by poor sanitation and unsafe drinking water. Although most people infected do not develop symptoms the bacteria remain present in faeces for one to two weeks after infection and contamination can go on to infect others.

In 1831, the conditions in which the second pandemic spread (there were six in total between 1817 and 1923) were little different to those in which Ebola is travelling today. And indeed there are some interesting parallels - from the developing official response, to riots and suspicion of the medical community.

The government's reaction as cholera made its way through Europe was to wait and see; although there was a greater degree of protection as an island then - with fewer travellers coming and going than we see today - a traditional quarantine policy would never have been 100% reliable. Screening ships' passengers and crews would not, as is happening with Ebola, have picked up the newly infected, although this was considered. Quarantine was seen as a greater risk to economic prosperity than the disease was to human life.

A 6,000-year-old temple holding human-like figurines and sacrificed animal remains has been discovered within a massive prehistoric settlement in Ukraine.

Built before writing was invented, the temple is about 60 by 20 meters (197 by 66 feet) in size. It was a "two-story building made of wood and clay surrounded by a galleried courtyard," the upper floor divided into five rooms, write archaeologists Nataliya Burdo and Mykhailo Videiko in a copy of a presentation they gave recently at the European Association of Archaeologists' annual meeting in Istanbul, Turkey.

Inside the temple, archaeologists found the remains of eight clay platforms, which may have been used as altars, the finds suggested. A platform on the upper floor contains "numerous burnt bones of lamb, associated with sacrifice," write Burdo and Videiko, of the Institute of Archaeology of the National Academy of Sciences of Ukraine. The floors and walls of all five rooms on the upper floor were "decorated by red paint, which created [a] ceremonial atmosphere."

The ground floor contains seven additional platforms and a courtyard riddled with animal bones and pottery fragments, the researchers found.

It was supposed to have been the definitive piece of scientific evidence that finally exposed the true identify of Jack the Ripper after he had brutally murdered at least five women on the streets of Whitechapel in the East End of London, 126 years ago.

A 23-year-old Polish immigrant barber called Aaron Kosminski was "definitely, categorically and absolutely" the man who carried out the atrocities in 1888, according to a detailed analysis of DNA extracted from a silk shawl allegedly found at the scene of one of his murders.

However, the scientist who carried out the DNA analysis has apparently made a fundamental error that fatally undermines his case against Kosminski - and once again throws open the debate over who the identity of the Ripper.

The scientist, Jari Louhelainen, is said to have made an "error of nomenclature" when using a DNA database to calculate the chances of a genetic match. If true, it would mean his calculations were wrong and that virtually anyone could have left the DNA that he insisted came from the Ripper's victim.

The apparent error, first noticed by crime enthusiasts in Australia blogging on the casebook.org website, has been highlighted by four experts with intimate knowledge of DNA analysis - including Professor Sir Alec Jeffreys, the inventor of genetic fingerprinting - who found that Dr Louhelainen made a basic mistake in analysing the DNA extracted from a shawl supposedly found near the badly disfigured body of Ripper victim Catherine Eddowes.

The imposing mosaic unearthed in the burial mound complex at Amphipolis in northern Greece might contain the best-ever portrait of Alexander the Great as a young man, according to a new interpretation of the stunning artwork, which depicts the abduction of Persephone.

It might also confirm previous speculation that the tomb belongs to Olympias, the mother of Alexander the Great.

The mosaic portrays the soul-escorting Hermes, Hades and Persephone. In reality, the mosaic most likely has human counterparts represented in the guise of the three mythological characters, said Andrew Chugg, author of The Quest for the Tomb of Alexander the Great.

"I am thinking very much that Persephone should be an image of the occupant of the tomb being driven into the Underworld," Chugg told Discovery News.

"That means an important queen of Macedon that died between 325-300 B.C. possibly at Amphipolis. So we are exactly where we always were: Olympias or Roxane," Chugg said.

Scientists, examining Britain's greatest Anglo-Saxon gold treasure collection, have discovered that it isn't quite as golden as they thought.

Tests on the famous Staffordshire Anglo-Saxon treasure, a vast gold and silver hoard found by a metal detectorist five years ago, have now revealed that the 7th century Anglo-Saxon goldsmiths used sophisticated techniques to make 12-18 karat gold look like 21-23 karat material.

Scientific research, carried out over the past two years on behalf of Birmingham City and Stoke-on-Trent City councils, which jointly own the hoard, has revealed that the Anglo-Saxon goldsmiths had discovered an ingenious way of, metallurgically, dressing mutton up as a lamb. It appears that they deliberately used a weak acid solution - almost certainly ferric chloride - to remove silver and other non-gold impurities from the top few microns of the surfaces of gold artefacts, thus increasing the surfaces' percentage gold content and therefore improving its appearance. This piece of Anglo-Saxon high tech deception turned the surfaces of relatively low karat, slightly greenish pale yellow gold/silver alloys into high karat, rich deep yellow, apparently high purity gold.

Archaeologists had never previously realised that Anglo-Saxon goldsmiths had developed such technology.

They had faces like rabbits and some were 2 metres tall. But now it seems that an extinct giant kangaroo didn't hop - it walked.

Known as "short-faced giant kangaroos", sthenurines roamed Australia for 12.5 million years before being wiped out 30,000 years ago. No one knows what killed off these relatives of modern kangaroos, although they may have struggled as Australia's climate grew more arid.

Unlike kangaroos today, these ancient giants walked just like us. "All our evidence fits with these animals leaning on one leg at a time, like humans," says Christine Janis of Brown University in Providence, Rhode Island.

She and her team took hundreds of measurements of the bones of 66 living species of the kangaroo family and 78 extinct species, including 71 from sthenurines, to calculate the likely size and function of each animal's bones and muscles.

They found that the ill-fated sthenurines had bone structures resembling those of animals that move by shifting weight from one foot to the other, like humans and apes (PLOS One, DOI). A flange at the base of their shin bones, similar to those found in horses and humans, would have prevented their feet from collapsing sideways under the weight of their body.

Quite a bit of what Matt Stirn, Rebecca Sgouros and a crew of volunteers found in the high Tetons remains to be told.

Partly because archaeology is a science, and the bits of data they found over two two-week expeditions on the west slope of the Teton Range still need to undergo intense study before any conclusions can be drawn.

And partly because the locations of these heretofore unknown, and unexplored, high-elevation archaeological sites are secret.

"At a few sites we found very little," said Stirn, who with Sgouros runs the Jackson Hole Historical Society and Museum's new archaeology program. "They were picked over. ... Mountain archaeology is so fragile as it is, because of the environment, we really need as much information as we can gather. When artifacts are taken, that prevents us from answering questions."

But the very fact that there are sites - some picked over, some yielding troves of evidence about Native American use and habitation of the high country dating back perhaps as early as 11,000 years ago - is exciting news.

Not that long ago archaeologists thought indigenous people of the region made short visits and spotty use of resources above 10,000 feet. The harsh conditions and unpredictable weather, it was assumed, would have mostly discouraged humans from all but brief visits to forage or for spiritual purposes.

Dozens of rock art sites in southern New Mexico, recently documented for the first time, are revealing unexpected botanical clues that archaeologists say may help unlock the meaning of the ancient abstract paintings.

Over a swath of the Chihuahuan Desert stretching from Carlsbad to Las Cruces, at least 24 rock art panels have been found bearing the same distinctive pictographs: repeated series of triangles painted in combinations of red, yellow, and black.

And at each of these sites, archaeologists have noticed similarities not just on the rock, but in the ground.

Hallucinogenic plants were found growing beneath the triangle designs, including a particularly potent species of wild tobacco and the potentially deadly psychedelic known as datura.