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A Bright Moon Impact

Fri, 17 May 2013 17:11:30 +0000

On 17 March 2013, NASA cameras captured the brightest impact on the Moon seen in eight years of monitoring. It lasted only a fraction of a second, but at the brightness of a fourth-magnitude star it could have been seen by anyone with binoculars and possibly with the naked eye. Six of the 17 frames are shown here. NASA calculates that a boulder 30 to 40 centimeters across, traveling at 25 kilometers per second, was responsible.

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Camels Often Sit Down Painfully . . .

Wed, 15 May 2013 14:53:06 +0000

When I went to geology school, I was already so advanced that I never used mnemonics—those anagram sentences that help students keep track of the names of the geologic time periods. A reader in the Forum has been using the good old sentence "camels often sit down carefully, perhaps their joints creak terribly" to remember the sequence Cambrian-Ordovician-Silurian-Devonian-Carboniferous-Permian-Triassic-Jurassic-Cretaceous-Tertiary. That marks her as both (1) a UK resident and (2) a bit behind the times. On the first point, American students memorize Mississippian and Pennsylvanian instead of the Carboniferous (although that puts us behind the times). On the second, the Tertiary period has been deprecated by the geologic time authorities (although many still find it useful) while the Quaternary period has been formalized. So the perfect mnemonic should end with three words after "creak" to mark the Paleogene, Neogene and Quaternary periods.

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This Week's Geo-Quiz: Micro Geology

Sun, 12 May 2013 14:15:13 +0000

Geology takes in subjects of all sizes from planets to molecules. Many of these have a micro component—that's not to stipulate that they're microscopic, or even minuscule, just, well, hey take the quiz now and you'll see. The quiz is definitely not about minutia, and if you can get through all 12 questions without seeing the WRONG! page, yours is a mighty jumbo-sized knowledge base indeed.

Geologists' New Pastime: Google Earth Engine

Fri, 10 May 2013 15:01:30 +0000

The people at Google Earth have unveiled a new feature of Earth Engine: time-lapse views of anywhere on Earth using satellite imagery back to 1984. My colleagues on Twitter have been exclaiming all morning:

@rschott: "The Evolving Earth: Meanders & Dunes & Shorelines Oh my!"

@kwinkunks: "Witness Alberta's oil sands development in Google's 100% awesome time-lapse Earth Engine"

@highlyanne: "Watch Oregon Inlet move sediment on the NC Outer Banks on Google Earth Engine

@davidmpyle: "Here's the whole #eruption of #Montserrat in Google Earth Engine"

@Allochthonous: "Mount Etna timelapse. Clearest new lava flows in NE around the 1999/2000 mark bit.ly/179ybKN"

@dukeofhazards: Wax Lake delta buildup

And it just goes on. These visualizations are wonderful ways to get us closer to the geologist's deep present by compressing time. As geo-tweeter @kwinkunks put it, "Just imagine how useful this will be in 10 million years. Can't wait... Oh, damn."

For my part, I've picked a few things for you to visit:

Movement of Malaspina Glacier, Alaska's largest piedmont glacier

The notorious Lusi mud volcano, Indonesia

Western Sumatra before and after the 2004 tsunami

Mouth of the Yellow River, world's largest sediment input to the ocean (corrected)

Feel free to post your own worthy spectacles.

Granitic Seafloor Reported Off Brazil

Wed, 08 May 2013 18:56:56 +0000

It's exciting in a geeky way to learn that the deep-sea plateau called the Rio Grande Rise appears to contain granitic rocks. Dredging two years ago brought up samples, and this week the "video evidence" from a submersible dive to the Rise was cited as further proof. That doesn't seem like much evidence, and nothing has been published yet, and the video I've seen doesn't look at all granite-y, but I'll go with it. Granite is a big deal, because the Rio Grande Rise is supposed to be a hotspot track created by a "mantle plume," and mantle plumes are not supposed to create granites.

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Famous (Former) Geologists: Andrei Tarkovsky

Mon, 06 May 2013 17:05:28 +0000

My last few weekends have been an introduction to the remarkable work of the Soviet filmmaker Andrei Tarkovsky (1932-86). He was a cinematic genius with rare gifts of vision, intellect and perseverance, but my ears especially lit up during disk 2 of the "Stalker" set, when his longtime set designer Rashit Safiullin mentioned that Tarkovsky had been a geologist before entering film school. He hinted that Tarkovsky's fieldwork in Siberia had influenced his vision.

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This Week's Geo-Quiz: Geology in Space!

Sat, 04 May 2013 14:15:24 +0000

No doubt most you are ready to stop thinking about Earth, this globally warming vale of tears, this stage mobbed with grunting masses and their incessant talk of fears and threats, this scene of fracking frissons and landslide wreckage and internecine warfare. Cast your minds skyward, then, and contemplate the clean, cold heights of outer space. Consider your knowledge of Earth above the ground and Earth's planetary siblings. Now pit your knowledge against this Geo-Whiz Quiz about space geology. If you feel a bit breathless, take your time.

The Glacier Picture Gallery

Fri, 03 May 2013 14:26:18 +0000

It's a hot day where I am. What could be better for that than a photo glossary devoted to glaciers and related features. Now you can bond with a bergschrund, get familiar with a fjord, recognize a roche moutonnée or spot a serac.
_{Iceberg — courtesy natalielucier via Creative Commons}

A Winning Geo-Poem on Faulting

Thu, 02 May 2013 16:50:35 +0000

The Zócalo Public Square website does all sorts of cultural things, among which is an annual contest for the poem that "best explores people's connection to place." Today they published the winning poem "Fault," by Southern Californian Jia-Riu Chong Cook, which takes as a theme the San Andreas fault. In "Fault," plate tectonics is a nimble metaphor for the precarious state of human relationships. I approve this message.

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First There Is a Hill, Then There Is a Mountain

Tue, 30 Apr 2013 22:19:40 +0000

What makes a hill a mountain? In my definition in the gallery of erosional landforms, I cite a criterion of 300 meters, a thousand feet. In Britain, the Ordnance Survey defines a mountain at twice that height. Hillclimbing is such a popular pastime there that it makes a real difference if you can claim that your local peak is a bona fide mountain, even if it's just a few centimeters higher than the 600 m cutoff. Today on the GIS Lounge, Caitlin Dempsey reports on the efforts of a couple of guys who have been re-surveying the hilltops of Britain, using high-grade GPS equipment, to make sure that every mountain shall be exalted. Thack Moor, their latest certified triumph, is now England's 254th mountain.