Dinosaur Killer Chicxulub Crater To Be Drilled For First Time

An artist's image of an asteroid Impact. Image Credit: University of California Observatories/Don Davis.

All over the Earth, there is a buried layer of sediment rich in iridium called the Cretaceous Paleogene-Boundary (K-Pg.) This sediment is the global signature of the 10-km-diameter asteroid that killed off the dinosaurs—and about 50% of all other species—66 million years ago. Now, in an effort to understand how life recovered after that event, scientists are going to drill down into the site where the asteroid struck—the Chicxulub Crater off the coast of Mexico’s Yucatan Peninsula.

The end-Cretaceous extinction was a global catastrophe, and a lot is already known about it. We’ve learned a lot about the physical effects of the strike on the impact area from oil and gas drilling in the Gulf of Mexico. According to data from that drilling, released on February 5th in the Journal of Geophysical Research: Solid Earth, the asteroid that struck Earth displaced approximately 200,000 cubic km (48,000 cubic miles) of sediment. That’s enough to fill the largest of the Great Lakes—Lake Superior—17 times.

The Chicxulub impact caused earthquakes and tsunamis that first loosened debris, then swept it from nearby areas like present-day Florida and Texas into the Gulf basin itself. This layer is hundreds of meters thick, and is hundreds of kilometers wide. It covers not only the Gulf of Mexico, but also the Caribbean and the Yucatan Peninsula.

In April, a team of scientists from the University of Texas and the National University of Mexico will spend two months drilling in the area, to gain insight into how life recovered after the impact event. Research Professor Sean Gulick of the University of Texas Institute for Geophysics told CNN in an interview that the team already has a hypothesis for what they will find. “We expect to see a period of no life initially, and then life returning and getting more diverse through time.”

Scientists have been wanting to drill in the impact region for some time, but couldn’t because of commercial drilling activity. Allowing this team to study the region directly will build on what is already known: that this enormous deposit of sediment happened over a very short period of time, possibly only a matter of days. The drilling will also help paint a picture of how life recovered by looking at the types of fossils that appear. Some scientists think that the asteroid impact would have lowered the pH of the oceans, so the fossilized remains of animals that can endure greater acidity would be of particular interest.

The Chicxulub impact was a monumental event in the history of the Earth, and it was extremely powerful. It may have been a billion times more powerful than the atomic bomb dropped on Hiroshima. Other than the layer of sediment laid down near the site of the impact itself, its global effects probably included widespread forest fires, global cooling from debris in the atmosphere, and then a period of high temperatures caused by an increase in atmospheric CO2.

We already know what will happen if an asteroid this size strikes Earth again—global devastation. But drilling in the area of the impact will tell us a lot about how geological and ecological processes respond to this type of devastation.





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Extinction Alert: Stephen Hawking Says Our Technology Might Wipe Us Out

Professor Stephen Hawking enjoying a lighter moment. Image credit: Zero G

If you’re thinking of having yourself cryogenically suspended and awakened in some future paradise, you might want to set your alarm clock for no later than 1,000 years from now. According to the BBC, Stephen Hawking will be saying this much in the 2016 Reith Lectures – a series of lectures organized by the BBC that explore the big challenges faced by humanity.

In Hawking’s first lecture, which will be broadcast on February 26th on the BBC, Hawking covers the topic of black holes, whether or not they have hair, and other concepts about these baffling objects.

But at the end of the lecture, he responded to audience questions about humanity’s capacity for self destruction. Hawking said that 1,000 years might be all we have until we meet our demise at the hands of our own scientific and technological advances.

As we have become increasingly advanced both scientifically and technologically, Hawking says, we will be creating “new ways that things can go wrong.” Hawking mentioned nuclear war, global warming, and genetically engineered viruses as things that could cause our extinction.

Nuclear War

Through the Cold War, annihilation at the hands of our own nuclear weapons was a real danger. The threat of a nuclear launch in response to a real or perceived threat was real. The resulting retaliation and counter-retaliation was a risk faced by everyone on the planet. And the two superpowers had enough warheads between them to potentially wipe out life on Earth.

The USA and the USSR have reduced their stockpiles of nuclear weapons in recent decades, but there are still enough warheads around to wipe us out. The possibility of a rogue state like North Korea setting off a nuclear confrontation is still very real. By the time Hawking’s 1,000 year time-frame has passed, we’ll either have solved this problem, or we won’t be here.

Global Warming

Earth is getting warmer, and though the Earth has warmed and cooled many times in its history, this time we only have ourselves to blame. We’ve been inadvertently enriching our atmosphere with carbon since the Industrial Revolution. All that carbon is creating a nice insulating layer around Earth, as it traps heat that would normally radiate into space. If we reach some of the “tipping points” that scientists talk about, like the melting of permafrost and the subsequent release of methane, we could be in real trouble.

Different climate engineering schemes have been thought up to counteract global warming, like seeding the upper atmosphere with reflective molecules, and having fleets of ships around the equator spraying sea mist into the air to partially block out the sun. Or even extracting carbon from the atmosphere. But how realistic or effective those counter-measures might be is not clear.

Genetically Engineered Viruses

As a weapon, a virus can be cheap and effective. There’ve been programs in the past to develop biological weapons. The temptation to use genetic science to create extremely deadly viruses may prove too great.

Smallpox and Viral Hemorrhagic Fevers have been weaponized, and as our genetic manipulation abilities grow, it’s possible, or even likely, that somebody somewhere will attempt develop even more dangerous viral weapons. They may be doing it right now.

There’s a ban on viral weapons, called the Biological and Toxin Weapons Convention signed in 1972. But, not everybody has signed it.

Artificial Intelligence

Hawking never mentioned AI in his talk, but it fits in with the discussion. As our machines get smarter and smarter, will they deduce that the only chance for survival is to remove or reduce the human population? Who knows. But Hawking himself, as well as other thinkers, have been warning us that there may be a catastrophic downside to our achievements in AI.

We may love the idea of driverless cars, and computer assistants like SIRI. But as numerous science fiction stories have warned us (Skynet in the Terminator series being my favorite,) it may be a small step from very helpful AI that protects us and makes our lives easier, to AI that decides existence would be a whole lot better without us pesky humans around.

The Technological Singularity is the point at which artificially intelligent systems “wake up” and become—more or less—conscious. These AI machines would start to improve themselves recursively, or build better and smarter machines. At this point, they would be a serious danger to humanity.

Drones are super popular right now. They flew off the shelves at Christmas, and they’re great toys. But once we start seeing drones with primitive but effective AI, patrolling the property of the wealthy, it’ll be time to start getting nervous.

Extinction May Have To Wait

As our scientific and technological prowess grows, we’ll definitely face new threats, just like Hawking says. But, that same progress may also protect us, or make us more resilient. Hawking says, “We are not going to stop making progress, or reverse it, so we have to recognise the dangers and control them. I’m an optimist, and I believe we can.” So do we.

Maybe you’ll be able to hit the snooze button after all.

Original Source: BBC News

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