90-year-old still studying ancient pollen

90-year-old still studying ancient pollen

Linda Heusser turns 90 on April 12, and the only birthday present she really wants is another sediment core to study.

Adjunct researchers at Columbia University’s Lamont-Doherty Earth Observatory analyzed pollen in marine sediments to better understand climate trends dating back 2.3 million years. For decades, she worked at Lamont on and off.

Her desk in Lamont’s old Geochemistry Building faces a wall of windows that look out onto the green campus. It’s covered in newspaper, surrounded by old books on geology and palynology (the study of pollen), and boxes full of microscope slides.

Heusser finds it difficult to walk, but she still has a sharp mind and a passion for her work.

The work starts with an ocean core—a long tube of mud drawn from the seafloor, whose sediment layers get older and older as you go down. She sifted the sediment through a nylon mesh to extract pollen grains, which ranged in size from 10 to 150 microns, or about the width of a human hair. This process may take several hours. She then processes the extracted material to remove other organic materials. “Pollen can survive hydrofluoric acid and all these nasty chemicals,” she says admiringly.

After the pollen was isolated, she placed the samples on glass slides, counted 300 pollen grains on each slide, starting with the nearest top layer, and counted which tree they came from. Each slide may take 2 or 3 hours. For Heusser, it’s a pleasure to look back in depth.

“It’s always exciting to get to the core and see how it’s developing, what’s going on,” she said.

When Heusser became a geologist, women didn’t really do that—especially mothers.

“It was very difficult to find women who were working and raising children at the time,” explains her colleague Dorothy Peteet, director of the paleoecology unit at the new core laboratory at the Doherty Earth Observatory in Lamont. “Linda was her own pioneer. She was my role model.”

Heusser collects samples on the Olympic Peninsula.

Heusser originally intended to be a social worker, just as her mother wanted. She studied psychology at Wellesley College in Massachusetts.

There are pros and cons to attending an all-female university. “You’re not being put down by men in chemistry or otherwise,” she said. “I didn’t know women were not equally accepted in grad school or in the workplace. I was so naive.”

She married her first husband during her senior year at Wellesley, completed her bachelor’s degree, and left academia for nine years to start a family. Then, one day, her husband brought home a book on historical geology. She remembers the excitement she felt when she read it. That’s when she knew she wanted to be a geologist.

“I never took a geology class. I never thought looking at a rock would tell me. But that book on historical geology did. It was god from the machine,” she says.

She spent a year taking as many geology courses as she could at Columbia University’s School of General Studies—while caring for her three children. She was then able to pursue a master’s degree program in geology at Columbia University. There is only one other woman.

Heusser is much older than the other students, so she doesn’t have much interaction. But during the project, she shared an office with paleontologist, evolutionary biologist and science writer Stephen Jay Gould. She earned a master’s degree in 1969 and then wanted to enroll in a doctoral program at Columbia University.

“I wanted the excitement of exploration,” Heusser explained. “I was told, ‘You can’t get a PhD because you’re a woman.’ That really happened. I was devastated. But there was NYU. So I went to NYU and they gave me a scholarship,” she laughs say.

“It was a time when Columbia geology needed white people, Ivy League schools and male students,” she said, sketching every feature on her fingers, “and that’s it.”

She received her Ph.D. in 1971. paper, she analyzed pollen and spores to reconstruct geological events over the past 48,000 years or so on the Olympic Peninsula in western Washington. She enjoys doing fieldwork there and taking samples along sea cliffs.

In her doctoral dissertation, Heusser reconstructed geological events along the sea cliffs on the Olympic Peninsula in western Washington.

“When I found the Pacific Northwest, sun-drenched, these evergreen forests, oceans? Oh wow.” To this day, her favorite pollen to come across on the slide is the hemlock, as she compares it to the Olympic Peninsula .

Heusser’s second husband, Calvin Heusser, a full-fledged palynologist, worked together. So when it came time to submit her paper for publication, “someone asked, ‘Well, did she write it, or did Heusser write it?’ So I knew I needed a separate field, and studying pollen in the ocean core was a new field. .”

A colleague at OSU proposed that she study pollen in long sediment cores drilled from the seafloor. Nick ShackletonAs one of the founders of paleoclimatology, he will study the same core by analyzing isotopes in the shells of marine-dwelling single-celled organisms called foraminifera, which record sea surface temperatures.

During the ice age, all the pollen in the samples from this area came from conifers. During warm interglacial periods, pollen became more diverse, including deciduous species.

“As I went through about a hundred slides, all of a sudden I came to alder, and I knew — that was the last interglacial,” she said.

Meanwhile, in England, Shackleton is looking for an isotopic phase known as 5e, the last interglacial period before today, which ended 116,000 years ago. He came to visit Brown University, where Heusser met with him and compared the results.

“He put his chart on the blackboard, I put mine on the blackboard, and it was there – 5e is Alder Peak. This is the first time a land record has been linked to a marine record from the last interglacial .” In other words, this is the first time anyone has been able to show that the oceans are changing at the same time that vegetation is responding to global climate change.

Linking ocean and terrestrial records is an important advance in paleoclimatology.

Being able to use the ocean core to understand what happened on land could help reveal the nature, duration and age of the last interglacial. For example, the presence of redwood, oak and Douglas fir pollen suggests that the last interglacial in the Pacific Northwest had vegetation similar to today.

Calvin Heusser’s friend Shackleton came to their home in Tuxedo, New York to write down the results. She remembered that Shackleton was still in operation when he was in Cambridge, so he would sleep until around noon and stay up in the middle of the night. Heusser was an early bird, so they only had time to write papers in the afternoon. They completed the paper in about three days.it is Published in Science 1979.

Since then, Heusser has analyzed pollen in ocean cores from around the world, including Southern California, Japan, New Zealand and Chile, establishing the first direct correlations between land and ocean records in these regions. Her work helps shed light on how Earth has responded to climate change since the Miocene epoch, about 2.3 to 5 million years ago. For example, her work documented the collapse of the California Current, which brought cold, nutrient-rich water to the West Coast during the past 550,000-year ice age.

Heusser works at Lamont’s core lab with the CLIMAP team, which is studying the core in the ocean to understand Earth during the last ice age. Heusser contributed through her pollen research on the California and Washington coasts and her dissertation with Shackleton. “It’s been a dynamic time, a very exciting time,” she said.

Heusser hiking in Chile during field research.

At the same time, she is struggling to balance work and family. She laughed at the thought of when she taught at NYU and Newark and had to run to pick up her daughter from ballet school at Lincoln Center in Manhattan.

Because she’s a working mother, Heusser can’t take months-long research cruises to retrieve sediment cores. But she does manage to go field work every now and then. For one, her husband works in Chile, and she will come as his field assistant. The Heussers also spent several springs at Clare Hall at the University of Cambridge, UK, where they became tenured fellows.

Heusser left her studies in 2004 to care for her then ailing husband. After his death in 2006, she began volunteering at a nearby mental health facility. “So I became the authority on teenage anxiety,” Heusser said with a laugh. At the time, she was in her 70s.

In 2010, at Pitt’s invitation, she returned to Lamont. “She jumped right back, and she’s been publishing ever since,” Peteet said. “She’s a fierce, hard worker. She’s very productive. In the lab, she does 24 samples at a time. I can never get more than 12.”

Heusser (top right) on a field trip to southern South America. Dorothy Peteet was third from the left. The tour was organised by Wally Broecker, third from the right in the back row.

Today, Heusser is analyzing cores Peteet has collected locally with the aim of improving sea-level models. She is also studying a deep-water core off the coast of San Diego that should provide the first detailed record of Southern California’s climate and vegetation since the last interglacial. Because of the region’s very dry climate, ocean records are critical. No lake can core.

A few weeks ago, Heusser celebrated her 90th birthday with her children and grandchildren.

“In terms of birthday gifts, the exciting thing about Dot [Peteet] Just told me, ‘Oh my God, we have a long core from Pyrmont [NY],’ “She’s done all the large fossils – would I be interested?”

Has she thought about retirement? “What would I do?” she asked. She’d rather stare into the microscope, explore the past, and wonder what she’ll find next.