Exploding Asteroid Theory Strengthened by New Evidence Located in Ohio, Indiana

Ken Tankersley
Ken Tankersley

Was the course of life on the planet altered 12,900 years ago by a giant comet exploding over Canada? New evidence found by UC Assistant Professor of Anthropology Ken Tankersley and colleagues suggests the answer is affirmative.

Geological evidence found in Ohio and Indiana in recent weeks is strengthening the case to attribute what happened 12,900 years ago in North America — when the end of the last Ice Age unexpectedly turned into a phase of extinction for animals and humans – to a cataclysmic comet or asteroid explosion over top of Canada.

A comet/asteroid theory advanced by Arizona-based geophysicist Allen West in the past two years says that an object from space exploded just above the earth’s surface at that time over modern-day Canada, sparking a massive shock wave and heat-generating event that set large parts of the northern hemisphere ablaze, setting the stage for the extinctions.

Now University of Cincinnati Assistant Professor of Anthropology Ken Tankersley, working in conjunction with Allen West and Indiana Geological Society Research Scientist Nelson R. Schaffer, has verified evidence from sites in Ohio and Indiana – including, locally, Hamilton and Clermont counties in Ohio and Brown County in Indiana – that offers the strongest support yet for the exploding comet/asteroid theory.

Samples of diamonds, gold and silver that have been found in the region have been conclusively sourced through X-ray diffractometry in the lab of UC Professor of Geology Warren Huff back to the diamond fields region of Canada.

The only plausible scenario available now for explaining their presence this far south is the kind of cataclysmic explosive event described by West’s theory. “We believe this is the strongest evidence yet indicating a comet impact in that time period,” says Tankersley.

Ironically, Tankersley had gone into the field with West believing he might be able to disprove West’s theory.

Tankersley was familiar through years of work in this area with the diamonds, gold and silver deposits, which at one point could be found in such abundance in this region that the Hopewell Indians who lived here about 2,000 years ago engaged in trade in these items.

Prevailing thought said that these deposits, which are found at a soil depth consistent with the time frame of the comet/asteroid event, had been brought south from the Great Lakes region by glaciers.

“My smoking gun to disprove (West) was going to be the gold, silver and diamonds,” Tankersley says. “But what I didn’t know at that point was a conclusion he had reached that he had not yet made public – that the likely point of impact for the comet wasn’t just anywhere over Canada, but located over Canada’s diamond-bearing fields. Instead of becoming the basis for rejecting his hypothesis, these items became the very best evidence to support it.”

Additional sourcing work is being done at the sites looking for iridium, micro-meteorites and nano-diamonds that bear the markers of the diamond-field region, which also should have been blasted by the impact into this region.

Much of the work is being done in Sheriden Cave in north-central Ohio’s Wyandot County, a rich repository of material dating back to the Ice Age.

Tankersley first came into contact with West and Schaffer when they were invited guests for interdisciplinary colloquia presented by UC’s Department of Geology this spring.

West presented on his theory that a large comet or asteroid, believed to be more than a mile in diameter, exploded just above the earth at a time when the last Ice Age appeared to be drawing to a close.

The timing attached to this theory of about 12,900 years ago is consistent with the known disappearances in North America of the wooly mammoth population and the first distinct human society to inhabit the continent, known as the Clovis civilization. At that time, climatic history suggests the Ice Age should have been drawing to a close, but a rapid change known as the Younger Dryas event, instead ushered in another 1,300 years of glacial conditions. A cataclysmic explosion consistent with West’s theory would have the potential to create the kind of atmospheric turmoil necessary to produce such conditions.

“The kind of evidence we are finding does suggest that climate change at the end of the last Ice Age was the result of a catastrophic event,” Tankersley says.

Currently, Tankersley can be seen in a new documentary airing on the National Geographic channel. The film “Asteroids” is part of that network’s “Naked Science” series.

The new discoveries made working with West and Schaffer will be incorporated into two more specials that Tankersley is currently involved with – one for the PBS series “Nova” and a second for the History Channel that will be filming Tankersley and his UC students in the field this summer. Another documentary, this one being produced by the Discovery Channel and the British public television network Channel 4, will also be following Tankersley and his students later this summer.

As more data continues to be compiled, Tankersley, West and Schaffer will be publishing about this newest twist in the search to explain the history of our planet and its climate.

Climate change is a favorite topic for Tankersley. “The ultimate importance of this kind of work is showing that we can’t control everything,” he says. “Our planet has been hit by asteroids many times throughout its history, and when that happens, it does produce climate change.”

Invisible Waves Shape Continental Slope, Researcher Says

A class of powerful, invisible waves hidden beneath the surface of the ocean can shape the underwater edges of continents and contribute to ocean mixing and climate, researchers from The University of Texas at Austin have found.

The scientists simulated ocean conditions in a laboratory aquarium and found that “internal waves” generate intense currents when traveling at the same angle as that of the continental slope. The continental slope is the region where the relatively shallow continental shelf slants down to meet the deep ocean floor.

They suspect that these intense currents, called boundary flows, lift sediments as the waves push into the continental slope, maintaining the angle of the slope through erosion. The action of the internal waves could also mix layers of colder and warmer water.

“Surprisingly little is known about how internal waves are generated and how they could lead to the mixing of the deep ocean, but it’s very important,” said physicist Hepeng Zhang. “Understanding ocean mixing is crucial for us to know whether changes in ocean circulation are the result of climate change or just variability.”

Zhang said that as long as there is tidal motion that generates internal waves traveling along the continental slope, intense boundary flow will be produced.

“Twenty-four hours a day, seven days a week over a long geological time scale, and this will maintain the angle of the continental slope,” he said.

He published his research with colleagues Harry Swinney and Benjamin King in Physical Review Letters.

Zhang studied internal waves using a simple saltwater aquarium equipped with a sloping bottom simulating the continental slope. Water in the tank increased in density from top to bottom, just as water is denser on the ocean floor. Thousands of very small particles, 10 microns or smaller, were suspended in the water.

As Zhang generated waves in the tank, he took photographs and video footage of the particles and then analyzed the particles’ direction of flow and velocity.

Particle motion revealed intense boundary flows when the angle of the bottom matched the angle at which internal waves can travel.

Oceanic continental slopes could theoretically reach angles of 15 to 20 degrees as sediments continually pour down from the continents, but Zhang said that the internal waves are limiting the angle to around three degrees, the average angle of continental slopes.

The internal waves could also play a role in larger ocean currents by bringing cold water up from the deep ocean to the surface at the equator.

Ocean currents form closed loops, with warm surface water, like the Gulf Stream, moving toward the poles and cold water circulating back toward the equator at depth. The warm surface water heated at the equator is largely driven to the poles by wind. At the poles, this water is cooled by the cold air and mixes with cold water from melting glaciers and ice. Although fresh water is less dense than sea water, the cooling effect wins out and the density increases until the water sinks.

Zhang found that the internal waves could help bring this cold water closer to the surface when the boundary flow pushes heavier, colder water over warmer lighter water on the continental slope. This results in the internal wave breaking and mixing on the slope, just as a surface wave breaks on the shore.

“How exactly this will contribute to ocean circulation, I really don’t know,” said Zhang. “But it is definitely a step we have to understand before we can understand global ocean circulation.”

Geologists show China quake was rare event

The mountains near the Min River south of Wenchuan City, close to the epicenter of the recent earthquake in China that has killed more than 65,000 people to date. - Photo Credi: Kristen Cook, MIT
The mountains near the Min River south of Wenchuan City, close to the epicenter of the recent earthquake in China that has killed more than 65,000 people to date. – Photo Credi: Kristen Cook, MIT

A new analysis of the setting for last month’s devastating earthquake in China by a team of geoscientists at MIT shows that the quake resulted from faults with little seismic activity, and that similar events in that area occur only once in every 2,000 to 10,000 years, on average.

However, the researchers caution that because earthquakes can sometimes occur in clusters, people should still be wary of another possible large-scale earthquake.

The magnitude 7.9 quake struck Sichuan province on May 12 at around noontime, which may have increased the human death toll because many people were at school, and the school buildings turned out to be especially vulnerable to collapse because of poor construction. More than 69,000 people have been confirmed dead so far, and more than 374,000 injured, with fears of further casualties because several lakes created by rockfall dams may give way and cause sudden flooding.

Clark Burchfiel, Schlumberger Professor of Geology, and Leigh Royden, professor of geology and geophysics in the Department of Earth, Atmospheric and Planetary Sciences at MIT, have been doing extensive research in that region of China and the Tibetan plateau for more than two decades, but had found no hints that suggested such a large earthquake might strike the area. They and several colleagues, including MIT’s Robert D. van der Hilst and Bradford H. Hager, who are both Cecil and Ida Green Professors of Earth Sciences, have published a paper analyzing the causes of the quake that appears in the July issue of GSA Today, a publication of the Geological Society of America.

The team operated an array of 25 broadband seismograph stations in this region of western Sichuan for more than a year. “Nobody was thinking there would be a major seismological event” in that area, Royden says. “This earthquake was quite unusual,” and may have involved a simultaneous rupture of two separate but contiguous faults, she continued.

The region is extremely unusual geologically, Royden says, because of the very steep slopes at the boundary between the Sichuan Basin to the east and the Tibetan plateau to the west. The elevation rises sharply by about 3,500 meters (more than two miles) over a span of only about 50 kilometers (about 30 miles).

The area where the quake occurred is part of the boundary between two of the Earth’s tectonic plates, where the Indian and Asian plates converge in an ongoing collision that has created the Himalayan mountains and the Tibetan plateau. But in central and eastern Tibet, unlike most other areas of continental collision, much of the movement of crust is hidden from view. Instead of thickening the entire crust by folding and faulting, the surface of the eastern Tibetan plateau is undeformed and is being lifted upward by thickening of a weak crustal layer more than 15 km below the surface.

The crust in this deep weak layer is flowing eastward away from central Tibet to escape from the area directly north of the Indian plate. But, in the area where the earthquake occurred, this rapidly flowing material is obstructed by a major obstacle, the Sichuan Basin. “The crust and mantle beneath the basin appears to form a hard, cold knot” that extends to 250 km depth, Royden says, that forces the flow to “wrap around the knot.” The huge elevation difference between the surface of the plateau and the Sichuan Basin provides the underlying stress that led to the quake, she says.

As the surface of the eastern plateau has risen, it has become increasingly incised by rivers. Four of the world’s 10 largest rivers, including the Yangtze, flow through the region, Royden says. “There are gorges two and a half to three kilometers deep, and hundreds of kilometers long–they dwarf the Grand Canyon,” she says.

The steep slopes within the river gorges make the region especially vulnerable when earthquakes occur, she says. “When you shake those valleys, everything just slides down into the river gorges and eventually washes out to sea,” she says.

Because of the extreme geological environment of this region, Royden says, it may be possible to learn about mechanisms taking place there that may also occur, at a smaller scale, in other places. In this way, it may reveal processes that are also relevant in other parts of the world but that would be much harder to discover in these other locations because they would be more subtly expressed.

The research was funded by the National Science Foundation. The MIT scientists are currently collaborating with geophysicists of the China Seismological Bureau (in Beijing and Chengdu, Sichuan) on a study of the structure and seismic hazard of the region.

Landslide buries climate change link

The dark curvy ridge running across the picture is the Waiho Loop moraine, dated to originate from the Younger Dryas cold event
The dark curvy ridge running across the picture is the Waiho Loop moraine, dated to originate from the Younger Dryas cold event

New findings by three University of Canterbury researchers could pour cold water on evidence that climate change is happening simultaneously around the world.

The discovery has been made as a result of a study of the Waiho Loop glacial moraine on the plain between Franz Josef township and the sea, and is described by co-author Professor Jamie Shulmeister as throwing “a cat among the paleoclimate pigeons”.

A moraine is a ridge which marks the end of an earlier glacier limit. Scientists have believed the Waiho Loop moraine was created during a brief cold snap about 13,000 years ago that also affected Europe and North America, and inspired the Hollywood blockbuster movie The Day After Tomorrow.

The Waiho Loop moraine is widely used as evidence for direct inter-hemispheric linkage in climate change. But these new findings suggest the loop – which sits near the South Island’s Alpine fault line – was the result of a landslide, not climate change.

Professor Shulmeister, who worked on the research with Associate Professor Tim Davies and honours student Daniel Tovar, says there has been a huge scientific debate on the climatic implications of the Waiho Loop. But no one had ever studied its sediments.

“When graduate student Dan Tovar had a look he discovered to our surprise that it was mainly made up of a rock type known as greywacke which is different to the rocks that make up all the other moraines in front of the Franz Josef glacier.

“This rock type occurs about 13 kilometres up the valley from the Loop. All the other moraines are predominantly composed of schist which outcrops near Franz Josef township. The greywacke was also rather more angular than the rocks in the other moraines, suggesting it had not been transported in water or at the base of a glacier.”

As a result of its findings, Professor Shulmeister’s team believes a large landslide dumped a huge volume of rock on top of the glacier causing it to advance and, when the advance stopped, the moraine was created.

The findings will be published this week in the prestigious international science journal, Nature Geoscience.