An Appalachian geologist studies past climate trends to better understand the effects of today’s global warming

By Linda Coutant and William Purcell

Like many North Carolinians, geologist Ellen Cowan travels with her family to the beach each summer. She loves the wind-sculpted sands and blue waters that make up North Carolina’s coastline, especially the Outer Banks. She takes her Appalachian State University geology students there, too, to study first hand the changing form of land and sea.

The trips are bittersweet for Cowan, whose climate change research in other parts of the world leads her to believe that the Outer Banks will eventually disappear.

“The thought of losing our coastal areas is unbearable,” said Cowan, a professor in Appalachian’s Department of Geology. “But I don’t believe my children will be able to enjoy it the way I have in my life.”

Cowan has witnessed dramatic change in the Alaskan and Antarctic landscapes, where giant glaciers are melting into the sea.

“I’m sad,” admits Cowan, who studied glaciers in Alaska for 20 years and recently returned from a three-month, multi-national research project in Antarctica. “I’ve been a witness to huge sections of glaciers shrinking. The ice recedes leaving bare rock, and vegetation flourishes where ice once stood.”

Information from the ocean floor

What induces sadness also offers new knowledge. An expert in marine glacial sedimentation, Cowan’s research in Alaska and Antarctica reveals Earth’s climate past – and provides clues to its future.

“Sediment is really a sensitive recorder of climate change,” she said. “We can read this rock record and tell how climate has changed in the past. It’s really interesting to look at the variability in climate and try to think what caused it.”

In Antarctica, the multi-national ANDRILL project – which stands for ANtarctic geological DRILLing – pulled up core samples reaching back almost 10 million years. That is the longest ever recorded. Cowan was one of four sedimentologists on hand as the long, skinny cores were brought to the surface. Their job was to describe the sediment in detail, log the information graphically and post it on the Internet so other ANDRILL scientists can use it in their research.

“The work we did allows all the other scientists to know what’s there,” Cowan explained. “There’s a whole group of other specialists, like paleontologists, paleomagnetists and geochemists, who will work on this core. For them to select what part of the core they’re interested in and what samples they want all comes back to our descriptions made in the field.”

Cowan was selected to participate based on her expertise in Alaska. Her research there was funded by the National Science Foundation and examined cores dating back about 12,000 years.

Deciphering Earth’s history

Scientists know there are times in the Earth’s history where there was no ice at all. So, how did this transfer of ice into the ocean raise the sea level? How did that affect life? “These are the questions we want to answer,” Cowan said.

In deciphering clues left in the mud, Cowan’s team looks at composition, grain size, microfossils and vegetation. These microscopic details reveal how life responded to warming and cooling temperatures.

They can determine how fast the change will come – centuries or decades. Though 100 years is a blink of an eye in geological time, Cowan warns that the Earth may be on the edge of a 21st-century climatological disaster.

“If it has happened in the Earth’s past, it can happen again,” said Cowan. “There are definite periods in our planet’s history where the climate changed dramatically in just decades, not centuries.”

If that happens, Cowan said, expect “a rapid rise in water – and by rapid I mean 30, 20 or even 10 years.” Pacific islanders would be affected first. “It is not flooding that will hit first, but rather a fight for fresh water as the salt water rises, mixes into the fresh and contaminates the water supply. We’re talking about the displacement and relocation of millions of people because no fresh water will be available,” she said.

Cowan says the United States won’t notice the rise in sea level until the country is hit by major storms. “If the sea level is just a bit higher, the damage from hurricanes and other storms will be more catastrophic.” She estimates that the Outer Banks will be the first to go, and cities near coastal areas would be in jeopardy because just a half-meter rise in water levels would go very far inland.

“The Earth went through this rapid glacial melting and water rising in the past, so it would be neglectful for us as geologists not to look at what happened,” she said.

“I hope there is still time to take action and turn this climate warming around,” Cowan said. “If we can reduce the output of carbon dioxide emissions, we do have a chance. You can’t do it quickly on a dime, but with small adjustments over time you can get it going in a different direction.”

Expert scientist, devoted teacher

Cowan believes strongly in providing research opportunities for students in Appalachian’s Department of Geology, which only has undergraduates. She has taken students on her trips to Alaska to conduct field work, and welcomed their help in Appalachian’s labs where she examines the core samples more closely.

“It is a unique experience for undergraduate students to be aboard major research vessels out at sea and to go on hiking expeditions on glaciers. These are things not many people will get a chance to see,” Cowan said.

“We’ve had enjoyable times traveling in the field together, but it’s also a way for them to recognize the challenges of doing scientific research – the fact that you pose questions that you may not always find the answers to. It’s much different from reading a textbook and thinking that everything is always known. In our research, we’re always finding out new things.”

Graduates of Appalachian’s Department of Geology have gone on to careers as teachers and geologists, and have entered programs for master’s and doctoral degrees.