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Science  12 Sep 2003:
Vol. 301, Issue 5639, pp. 1472-1473
DOI: 10.1126/science.301.5639.1472b


Mongolian Frost Rings DEE BREGER Magnification: 35x Sample courtesy of G. Jacoby

A core sample from a Siberian pine tree in Mongolia tells a cold, dark tale. Dee Breger used a scanning electron microscope (SEM) to create this image of the tree's rings spanning the years A.D. 535 to 539. The narrow, deformed rings at the center of the image correspond to the years 536 and 537. The ruptured cells graphically record a catastrophic summer cooling that froze the tree's sap—a climate blip that has been linked to a massive eruption of a young volcano, the precursor to Krakatoa, or possibly an impact event.

Breger, who manages the SEM and X-ray Microanalysis Facility at Lamont-Doherty Earth Observatory in Palisades, New York, framed the cold season with normal tree rings for context. She colorized the image, using Adobe Photoshop, “to enhance its appeal,” she says. The hues are slightly more vibrant than pine but still look like wood.

“It's the tiniest fragment of an ancient tree, and yet it tells a story of global proportions,” says panel of judges member Thomas Lucas. “That's why it won: because it was an astonishing story encapsulated in a teeny, teeny little thing.”


Black Sea Pyrite DEE BREGER Magnification: 6400x Sample courtesy of W. Pitman, W. Ryan, and C. Major

Lamont-Doherty's Dee Breger also took the second spot with another scanning electron micrograph that has connections to ancient history. The image shows a tiny cluster of pyrite crystals forming inside a microplankton called a coccolithophorid, taken from sediments in the Black Sea. The pyrite has replaced one cell nestled among the original armoring plates that composed the plant's calcareous shell.

The chemical reaction that creates pyrite occurs when marine sediments lack oxygen. This indicates that the bottom of the Black Sea was lifeless and stagnant when the coccolithophorid was deposited thousands of years ago. The unbroken plates surrounding the pyrite also suggest that there was no life present to break them down. Such anoxic conditions may have arisen from a rush of salty Mediterranean water flooding the original freshwater “Black Sea Lake,” an event that could have been the biblical Noah's flood. The salt water would have sunk to the bottom, creating a layer of oxygen-free water.

Breger colorized a scanned darkroom print using Photoshop. “I chose to portray the realistic gold of pyrite while enhancing the shell with blue-green shadows for greater aesthetic appeal,” she says.

Breger's image is “very fine,” says panel of judges member Felice Frankel, “especially because of the story behind it.”


Buckling Nanotube With Conductivity Map MICHAEL STADERMANN

At first glance, the image could be a three-dimensional map of a pier jutting off a coastline, or some strange earthwork. But it is on an entirely different scale: a carbon nanotube, resting on a silicon dioxide surface, next to a smattering of gold atoms.

Michael Stadermann, a physicist at the University of North Carolina, Chapel Hill, made this image with an emerging technique called conductance-imaging atomic force microscopy that measures a sample's topography and conductivity simultaneously. The conductivity appears as color—the brighter the color, the higher the conductance—superimposed on the topography.

Merging the different properties of the object into one image provides clues to how they interact. Stadermann thinks the brighter spots indicate where the tube is buckling, which changes the tube's contact area with the probing tip.

Panel of judges member Donna J. Cox said that the judges gave the piece honorable mention because of Stadermann's “effort at pioneering a visualization technique in a very challenging area,” in addition to communicating two very different kinds of data sets on the same page.

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