Underground again today

glass plate

Posting will be light today, as I am joining University of Arizona PhD student Sarah Trube and several other Arizona cavers on a cave trip to collect water samples in a southern Arizona cave. This is in connection with research Sarah is doing to analyze the chemistry of cave dripwater and how it leads to the formation of cave speleothems. Moreover, she is tracking water flow and attempting to link it to climate and weather variations over time.

I noticed Sarah’s water collection equipment on my first Tucson-area cave trip back last January. In one case she had attached a tube to the bottom of a stalactite which fed the dripwater into a bottle. In another case she placed glass plates on top of stalagmites to allow the dripwater to drip onto the plate and then evaporate. Last month I joined her on one of her collection trips, where she gathered glass plates for later analysis in the lab. Though the plates had not been in cave more than a few months, you could easily see a thin layer of calcite deposit on their surface.

Below the fold is an image of Sarah gathering dripwater during an earlier trip.
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What is this stuff?

What is this stuff?

The uncertainty of science: In this week’s release of images from Mars Reconnaissance Orbiter, the science team posted the image on the right and asked, “What is this stuff?”

Here’s a hypothetical geologic history that might explain this scene: layered sediments were deposited by water or airfall (including volcanic pyroclastics). A crudely polygonal patterned ground was created by stresses in the sediments, and groundwater followed the fractures and deposited minerals that cemented the sediments. This was followed by perhaps billions of years of erosion by the wind, leaving the cemented fractures as high-standing ridges.

Of course, this story is almost certainly incomplete if not totally wrong.

Click here to see the close-up subimage from which I cropped the image on the right.

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A big sideways slip on Mars

Mars Reconnaissance Orbiter today released an image of a really spectacular transform fault on Mars, a spot where the ground cracked and two sections moved sideways to each other. In this case, the sideways movement was about 300 feet. The image is posted below the fold.

Compare that with the Japanese magnitude 9 earthquake on March 11, which only shifted the seabed sideways 165 feet while raising it 33 feet. The quake that moved these two pieces of Martian bedrock sideways must have been quite a ride.
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The trial of seven Italian earthquake experts facing manslaughter charges for not correctly predicting an earthquake continued this week.

The trial of seven Italian earthquake experts facing manslaughter charges for not correctly predicting a deadly earthquake continued this week.

The prosecution’s argument that the experts had underplayed the possible occurrence of a major quake was bolstered by testimony from Daniela Stati, the former civil protection officer for Abruzzo, who took an active role in the March 31 meeting. Stati confirmed what she had previously told prosecutors in 2010, that one of the indicted said during the meeting that the continuing tremors represented a “favorable signal” because there was a continuous discharge of energy that made stronger tremors less likely. In fact, scientific evidence suggests that groups of small earthquakes tend instead to increase the chances of a major earthquake nearby, even though the absolute probability of such a quake remains low. Stati said that nobody within the commission objected to this statement. She also underlined that the “reassuring message” given to the press by her, L’Aquila Mayor Massimo Cialente, and two of the indicted, Franco Barberi and Bernardo De Bernardinis, was based on comments made at the meeting.

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On the way to its winter haven, Opportunity found more evidence of water on Mars

On the way to its winter haven, Opportunity found more evidence of liquid water that once flowed on Mars, specifically a geological vein that they think might be gypsum.

The vein examined most closely by Opportunity is about the width of a human thumb (0.4 to 0.8 inch, or 1 to 2 centimeters), 16 to 20 inches (40 to 50 centimeters) long, and protrudes slightly higher than the bedrock on either side of it. Observations by the durable rover reveal this vein and others like it within an apron surrounding a segment of the rim of Endeavour Crater. None like it were seen in the 20 miles (33 kilometers) of crater-pocked plains that Opportunity explored for 90 months before it reached Endeavour, nor in the higher ground of the rim.

According to what project scientist Steve Squyres said at a press conference today at the AGU meeting, “This is the single most significant piece of evidence that liquid water once flowed on Mars.”

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The explosive Kilauea volcano

At a press conference just completed at the American Geophysical Union meeting in San Francisco, geologist Don Swanson of the U.S. Geological Hawaiian Volcano Observatory revealed that the Kilauea volcano on the Big Island of Hawaii has been in an explosive mode about sixty percent of the time in the past 2500 years. “Kilauea is not the gentle volcano that most people assume,” noted Swanson.
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Colorful Vesta

False color of Vesta

Tonight’s press conference at the American Geophysical Union conference focused on the latest results from Dawn, orbiting the giant asteroid Vesta. Or to put it as scientist Vishnu Reddy put it, “Vesta is the most colorful asteroid in the solar system.”

At least, in geological terms. To our human eye the asteroid wouldn’t be so spectacular. However, the false color images released by the scientists show the global geological diversity of Vesta. From the press release:
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