蘑菇短视频

Do you want to know how the world ends?

Visit Antarctica.

Travel to the southern tip of South America to the port city of Punta Arenas, Chile. Then board a small research vessel with 20 other scientists from a dozen universities across the United States and cross the perilous seas of the Drake Passage.

Go three days south through towering waves to the ice-choked waters surrounding the Antarctic Peninsula and wait there 鈥� until the wind鈥檚 finally blowing right and slowly enough.

From there, board your Zodiac. Motor to the nearest gravel shore with your colleagues, your picks and chisels in tow, and behold the sheer white cliffs of Seymour Island and the litter of fossilized ammonites and clams frozen in half-life at your feet.

Your answer is in front of you, buried there with the bones and minerals of the last extinction 鈥� if you know how to look for it.

And 蘑菇短视频 professor of geochemistry Shane Schoepfer is just such an expert.

Over his nine years teaching at 蘑菇短视频, Schoepfer has invited dozens of students to study extinction events written in stone around the globe. He鈥檚 taught summer field courses from Canada to Montana to our own Piedmont region to study minerals and sediments from throughout the geological timeline.

Schoepfer took the journey south to peak at the world 66 million years ago, and to ask how specifically the end-Cretaceous extinction transpired. His samples, now housed in 蘑菇短视频鈥檚 laboratories, will be processed and tested by current Catamounts to help answer that question and, in so doing, glance at our own future.

鈥淧aleoclimatology is understanding climates from the geological past, and since we can't go back in time and measure things like temperature or precipitation or things we could just measure directly today, a lot of that understanding comes from proxies, things we can measure indirectly in the rock record,鈥� Schoepfer said.

鈥淭here are ways of measuring temperature from shell material. You can determine the temperature that it formed at. There are ways of measuring the salinity of the sea water that sediments are deposited in. There are a lot of ways of looking at how much oxygen was dissolved in that water. So putting all of those things together and trying to understand environments from the deep past, indirectly, from the sediments that they left behind.鈥�

It鈥檚 broadly agreed upon since the 1980鈥檚, Schoepfer explains, that the extraterrestrial impact in the Yucatan Peninsula had a central role in inciting the extinction of most terrestrial and aquatic life. It鈥檚 evidenced not only by the Chicxulub crater, but by layers of the rare element iridium in sediments across the globe.

鈥淲hat's still kind of an open question,鈥� Schoepfer said, 鈥渋s around the same time at the end of the Cretaceous period, there are also massive volcanic eruptions happening in what's now India鈥�So India is not really India yet. It's a piece of Gondwana that's rifting away its own little microcontinent. And it is experiencing these flood basalt eruptions, where magma is essentially just pouring out of fissures in the earth and covering a wide area. And in India, this creates what's now called the Deccan Plateau.

鈥�When you have this type of volcanic eruption, you also typically have acidification of the shallow ocean. You have warming of the climate. You have a slowdown in ocean circulation that leads to a lot of the ocean becoming low oxygen. You have changes in rainfall patterns. And all of that by itself seems to have caused two of the major five mass extinctions in the rock record, and several of the smaller ones.鈥�

鈥淲e're interested in exploring the idea of 鈥榃ere Cretaceous ecosystems becoming stressed before that impact happened? Were they already kind of in crisis and that impact was the final straw that broke the camel's back? Or was it really that Cretaceous ecosystems were doing fine right up until the very end, and could have just kept on going if that impact had never occurred?鈥欌��

Seymour Island offers a unique opportunity to study this period of geological history, Schoepfer describes. There鈥檚 been little movement tectonically in the millions of years since the extinction, and high sediment deposition rates mean that scientists can look far into the past with a greater degree of detail.

A major difficulty in collecting and studying samples from the island is the Antarctic freeze-thaw cycle, and the way it muddles and disturbs the layered ground underfoot. Across the island there is a four-to-five-foot layer of 鈥渞ind,鈥� to use Schoepfer鈥檚 words, that isn鈥檛 associated with any particular time horizon and crosscuts the distinct bands visible at the cliffs.

Samples from this rind can only offer a blurry picture of the timeline, and to get around this Schoepfer employed two methods.

By walking along the beach and harvesting directly from the banded cliff face, which descended steadily at roughly 10 degrees, Schoepfer could sample layer after layer, millennia after millennia, simply by walking forward.

By collecting from freshly eroded sediment, Schoepfer could gather samples unaffected by the muddling typical of samples subject to the freeze-thaw cycle.

To get around the same obstacle inland, Schoepfer and his colleagues drilled 50 feet in the Earth to collect core samples. By digging trenches with shovels directly adjacent to their drill site, they hoped to compare this new method of sampling against what鈥檚 typically been done on the island.

鈥淚 think this core and these cliff samples are going to allow us to understand how environments were changing in the period leading up to the end-Cretaceous mass extinction,鈥� Schoepfer said.

鈥淲e will be able, using geochemical tools, to understand when we start seeing the impacts of volcanism, how that's affecting what fossil species are able to live in that environment, how the salinity of the environment was changing, which might reflect rainfall, how oxygen in the environment was changing. And that'll help us understand how marine environments respond to rapid change and extreme conditions.鈥�

The samples collected by Schoepfer now housed in 蘑菇短视频鈥檚 laboratories have the potential to change how we understand the Anthropocene and this sixth major mass extinction event some expert claim we鈥檙e in the midst of.   

In the month he spent aboard the R/V Sikuliaq, a vessel owned and operated by the University of Alaska on its inaugural trip to Antarctica, Schoepfer and his colleagues only had seven days where the conditions were right for sampling.

But he returned with millions of years for 蘑菇短视频 students to study, and the chance for interested Catamounts to participate in a potentially historic moment of discovery.

鈥淗aving some research experience as an undergraduate is a really great thing to have on your resume, and there's a lot of opportunities to get involved in that here,鈥� Schoepfer said.

鈥淚t's always a good opportunity to jump on that and learn from what you see because you never know when something you see in the field is going to be useful or applicable somewhere else.鈥�