May 24, 2013, 12:19 pm
David Ferguson and his colleague Sebastian Watt (above) learned a lot from Chilean road cuts, some striated with layers of basaltic scoria.
If there’s a lesson David Ferguson has learned in his early years as a volcanologist, it’s this: Always carry a big hammer.
“You just have to pound away, smash as much rock as you can,” said Ferguson, a postdoc at Columbia University’s Lamont-Doherty Earth Observatory. “There’s nothing more frustrating than having gone all that way and then you discover your hammer isn’t big enough.”
He will need that persistence as he taps away at one of the most vexing problems in volcanology: Does the rock hold evidence that climate changes have, over time, caused a surge of volcanic eruptions?
The idea does sound implausible, Ferguson acknowledged during a visit I made to his…
April 30, 2013, 5:19 pm
Above all else, Charles D. Keeling was fastidious with his data.
A couple of years ago, I found myself on assignment at Mauna Loa Observatory, the U.S. weather station perched just below the summit of a Hawaiian volcano. Spurred by Keeling, a longtime climate scientist at the Scripps Institution of Oceanography, this lab—still not much more than a bunch of prefab white containers sited below lava breaks—has measured the accretion of heat-trapping carbon dioxide in the atmosphere for 55 years. When Keeling began, those concentrations sat at 315 parts per million. That’s an idyllic level by today’s standards.
Indeed, as you may have heard, the CO2 monitors at Mauna Loa will soon reach—if temporarily—400 parts per million. They’ve already touched 400 ppm for at least an hour, and it’s likely that a daily average will top that level as well this month. (Stations in the A…
February 26, 2013, 11:14 am
The Soufrière Hills eruption in Montserrat in 1995
Scientific outlines of global warming have remained relatively unchanged for decades. Climate scientists, however, armed with better satellites and long-term data, continue to refine their understanding of the jogs up and down that typify the planet’s surface temperature, which can remain flat for years at a time before rising again. There are many pieces to this puzzle, and for more than a decade, one mystery has been centered high in the sky, in the freezing stratosphere.
Given its height, many miles above sea level, the stratosphere is typically a barren place. Suspended above the weather, this dry atmospheric layer rarely houses anything more tangible than gases. Occasionally a vast volcanic eruption—like Mount Pinatubo, in 1991—might inject a load of…
February 20, 2013, 1:33 pm
Ancient rice paddies released significant amounts of methane into the atmosphere, but scientists disagree on whether they helped trigger a change in climate.
When did the Epoch of Man begin?
In recent years, it’s become common to hear that the earth has entered the Anthropocene, a new geological time dominated by humanity. The term, very much a meme, unifies a host of environmental concerns—climate change, biodiversity loss, pollution. It’s so influential that the body governing geological time is now studying, as I detailed last year, whether to consider the Anthropocene as a formal epoch—like the Pleistocene or Miocene—to the chagrin of some stratigraphers, the fastidious adherents to the discipline that judges such things.
If we are to enter a new epoch, though, geologists will have to decide when…
November 8, 2012, 3:44 pm
In one of Dr. Seuss’s better-known tales of jealousy and prejudice, the Sneetches with stars on their bellies are considered superior to those without.
Now there’s more evidence that journals’ impact factors are similarly misleading.
A study published by three Canadian researchers has identified a two-decade-long trend in which the world’s top-ranked scientific journals are slowly losing their share of the most-cited articles.
The study, published in the November issue of the Journal of the American Society for Information Science and Technology, found that in 1990, 45 percent of the top 5 percent of the most cited articles were published in journals whose impact factor was in the top 5 percent—publications like Cell, Nature, Science, and the Journal of the American Medical Association. By 2009, that rate had fallen to 36 percent, the authors found.
August 2, 2012, 5:51 pm
ChemCam in action, in an artist’s view.
Early on Monday, after a tricky parachute descent, a hovering spacecraft will lower the new Mars rover, Curiosity, to the planet’s surface with long cables. If the nail-biting, never-before-tried maneuver works, the remote-controlled vehicle will begin searching for signs of water—and life. Bethany Ehlmann, an assistant professor at Caltech, will play a key role. From a control room in Pasadena, Calif., she will blow holes in rocks with a laser on the rover, creating clouds of atoms that could hold evidence of water. She spoke with The Chronicle about the quest.
Q. This sounds like a point-and-shoot game, something in a video arcade.
A. I can see that. This is the first time …
July 23, 2012, 1:50 pm
Forty years ago today, NASA launched its first Earth-observation satellite, Landsat. Data from the program, now on its eighth orbiter, have been used in climate-change studies, in ecology, and to show the effects of population growth.
Scientists have also noticed that some images are just visually amazing. (Particularly when the researchers add color to the pixels.)
Here are two of the most popular, voted on by 14,000 members of the public. The first contrasts the graceful oxbow bends of the Mississippi with the blocklike parcels of land that surround it. The second highlights one of the largest—and least-seen—river deltas in the world: the Yukon Delta in southwest Alaska, featuring a multitude of ponds, sloughs, and other water-forms.
(Credit: NASA’s Goddard Space Flight Center/USGS)