Wednesday, October 26, 2005

NM Tech grad earns national award

Award honors women who make an impact on geoscience

Argen Duncan El Defensor Chieftain Reporter

A New Mexico Tech graduate didn't come up dry after researching the behavior of water in the desert ground while earning her doctorate degree.

U.S. Geological Survey research hydrologist Michelle Walvoord, who earned her doctorate in earth and environmental science from Tech in 2002, not only discovered a previously unknown reservoir of nitrogen and noted desert plants' tendency to hamper replenishment of the groundwater supply, but also recently won a national award for the work.

The Geological Society of America honored Walvoord with the 2005 Subaru Outstanding Woman in Science award at the group's annual meeting Saturday, Oct. 15, in Salt Lake City.

Walvoord, who also has a master's degree in hydrology from Tech, said she was thrilled to receive the award.

"It was nice to be honored by a society that advocates student research and encourages women and minorities in science," she said.

According to a USGS press release, the award honors women who made an important impact on geoscience with their doctoral research. They are eligible for the award up to three years after they earn the degree.

"Michelle Walvoord's dissertation research on water movement in desert soils resulted in the discovery of unexpectedly large concentrations of nitrate in subsurface soils," wrote award selection committee chairman Jean Bahr. "This result, published in (the scientific journal) "Science," in 2003, has caused a major rethinking of the nitrogen budget for desert environments with important implications for understanding desert ecosystems and predicting the response of these systems to global climate change or human activities such as irrigation."

Bahr wrote that Walvoord's dissertation research sparked other articles, and added that she served as the first author in several pieces and is a National Research Council postdoctoral scholar, as well as a USGS researcher.

For her doctoral research, Walvoord worked in the Mojave and Chihuahuan deserts under the direction of Tech hydrology professor Fred Phillips.

She studied movement of water in the area between the ground's surface and the water table. She found that desert plants use all available water on a yearly basis, meaning those areas don't provide dependable groundwater recharge.

This has been happening for up to 10,000 to 15,000 years, she said.

During the research, Walvoord found a large, previously unaccounted for reservoir of nitrogen in the form of nitrates in the soil, a discovery that caused a stir in her field.

Scientists thought lack of nitrogen limited desert plants, but the vegetation at her research sites was not using what was available and may have allowed it accumulate over a long period of time.

If all of Earth's deserts contain such a reservoir, Walvoord said, nitrogen in these areas could constitute a large portion of the planet's nitrogen supply, though the atmosphere is the biggest reservoir.

Also, she said an environmental change, such as in climate or human action, could flush the nitrates into groundwater, causing health concerns.

Now, Walvoord does computer modeling of the region between the surface and the water table.

Although she lives in Golden, Colo., she is working to quantify the amount of groundwater that flows into the Yukon River in Alaska.

"It ties into a study that's looking at how carbon exports from the Yukon River Basin to the Bering Sea are changing over time due to climate change," she said.

Walvoord said she chose her career field because of a long-time interest.

"I've always been interested in water resources, particularly in areas where the water availability is low," she said.

Walvoord also said she is "curious about how the earth works."

aduncan@dchieftain.com

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