Posts

March 27, 2015

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12:42 PM | Beautiful meteorites hold clues to solar system’s violent start
What was happening (geologically speaking) on Earth way back when it was a mere babe and being showered with meteorites? Until a time machine is […] The post Beautiful meteorites hold clues to solar system’s violent start appeared first on Smithsonian Science News.

March 26, 2015

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2:00 PM | Tsunami Preparedness Week: Building a Network of Awareness
Tsunamis are a worldwide menace with specific local threats. It pays to learn your local situation and keep the knowledge fresh in your community.
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1:17 AM | Geo 1095: March 25, Day 814: Ignimbrite!
About nine days ago, @Volcanologist tweeted, "A mini erosive scour at the base of the Fasnia Ignimbrite, Tajao, Tenerife." (Click here to see accompanying photo.) If you take a look at that picture, you can see numerous similarities to the above and previous post. In the above photo, the lens cap is in the same spot as in the previous post, and I've just moved the frame a bit to the right, and come in a little closer. @Volcanologist confirmed that this looked like an ignimbrite, too, though I […]

March 25, 2015

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7:05 PM | Geo 1095: March 24, Day 813: Dim, Not Bright
...is how this rock made me feel. I recognized the parts, but had no idea of how it could have happened.Now, to non-geology types, that may not make a whole lot of sense. Here's the thing: all geology is about change. Something changed, or that rock (or land form, or what have you) wouldn't be there, or in that form. What geology struggles to do is to tell stories about what changed, how, and maybe why ("why" in terms of causal mechanisms). Just eyeballing this rock, I roughly estimate the […]

March 24, 2015

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10:23 PM | Earth Has A Layer No One Knew About
Our perspective of Earth tends to be very shallow--literally. Everything we experience, from the deepest depths of the ocean to the highest mountain peaks, only skims the…
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9:30 PM | This Lost Map Changed How We Saw the World
In 1815 William Smith drew a map of the United Kingdom which transformed the scientific landscape: It laid the foundations for modern geology, and identified natural resources which would beget the Industrial Revolution. But up until last year, this first-edition copy was considered to be lost forever.Read more...
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4:40 PM | Aussie Scientists Say This Is The Largest Asteroid Impact Area On Earth
Measuring 250 miles (400 km) wide, the now-buried crater in Australia was ground zero for a cataclysmic impact that occurred some 300 million years ago. But is it really the largest on Earth?Read more...
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1:09 PM | Geologists Discover New Layer in Earth’s Mantle
New research led by Dr Hauke Marquardt of the University of Bayreuth, Germany, suggests the existence of a previously unknown superviscous layer inside our planet: part of the lower mantle where the rock gets 3 times stiffer. Such a layer may explain why tectonic plate slabs seem to pool at 930 miles (1,500 km) under [...]
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3:09 AM | To Ski…Or Not To Ski?
Spring has sprung at last, but it seems as though it has been here for months already. Usually, snow can linger well into summer, up on the high plateaus of southern Utah. Several weeks ago, two friends and I hoped it would last at least through the middle of March. We wanted to ski, and we wanted to ski at Bryce Canyon. To ski you need snow, and there has been a noticeable lack of it this winter. Temperatures have been higher than average here in Utah, with conditions great for hiking but […]

March 23, 2015

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11:55 PM | Geo 1095: March 23, Day 812: Baffling Bedrock
There is talus raveling down the small gullies to the left and upper right, and the base of a larger talus cone in the lower right. Note that most of the plants are rooted in that talus, which can hold small amounts of moisture later into the dry season. In the lower middle of the photo, there are some angular, larger cobbles of rock, which I suspect have fallen from the overlying lahar deposits. The remainder of what is seen here is a fairly light rock, overall, but with many much darker small […]
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7:36 PM | A History of Geological Maps: I. From Outcrop to the first Map
March 23, 1769 marks the birthday of pioneering stratigrapher William Smith, who is also credited as author of the first modern geological map, however like many other great accomplishments also Smith’s idea of depicting the distribution of rocks on a topographic map didn’t materialize out of nowhere.The German mining engineer Georgius Agricola (1494-1555) dedicated in his “De re metallica” (1556) -  an early  textbook on mining technologies – an entire […]
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5:51 PM | Ancient Doomsday Asteroid Impact Found in Australia
Two vast underground domes are buried under central Australia that researchers have realized are the scars of the biggest and most powerful asteroid impact yet found on Earth.
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5:38 PM | Giant Asteroid Impact Basin Found in Australia
A 400 km-wide (250 mile-wide) impact basin from a massive asteroid that broke in two moments before it slammed into our planet has been found in north-eastern South Australia by a team of scientists, led by Dr Andrew Glikson of the Australian National University’s Planetary Science Institute. The twin scars of the impacts – the [...]
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5:30 PM | Just Discovered In Australia: The Largest Asteroid Impact Ever
A long time ago, a huge meteorite entered the earth's atmosphere in a screaming fireball. In its last violent moments, it split into two massive pieces, each at least 6…
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4:20 AM | Holocene
To follow up on my post about the Anthropocene, check out this excellent song by Bon Iver named after our current geologic period.
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12:08 AM | Geo 1095: March 22, Day 811: Badlands Close-Up
Here we have a closer look at how the lower unit has weathered and eroded into an (albeit small-scale) example of badlands morphology (described in more detail a few posts back). It was about this point I realized this rock was not what I expected it to be, which was a more or less homogenous, uniformly composed, ash bed. Having driven by this outcrop probably nearly a hundred times, I was assuming an unwarranted degree of familiarity. Pro-tip: Never make assumptions about rock you haven't […]

March 22, 2015

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3:08 PM | Montgomery and Wartman: Invest in Landslide Mapping
How to Make Landslides Less Deadly (Montgomery and Wartman in NY Times)Alas they were word limited - but point out the need for a modest investment in developing landslide maps.
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2:00 PM | The Mystery Of The Canyon With Two Mouths
One canyon on Earth has two mouths - but that is not the only mystery.First formally documented by western explorers mapping the Colorado Territory in the 1800s, Unaweep Canyon is a puzzling landscape and so it has inspired numerous scientific hypotheses for its origin. A new paper published in Geosphere by Gerilyn S. Soreghan and colleagues brings together old and new geologic data of this region to further the hypothesis that Unaweep Canyon was formed in multiple stages.read more
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12:24 AM | Geo 1095: March 21, Day 810: Dana for Scale
Getting a close look at interesting exposures are often difficult or impossible, contrary to expectations at first glance. I'd have loved to get a closer look at the tentative contacts in the upper unit, but it wasn't to happen. The talus cones above the ditch (Dana is standing at the left base of one of them) are at the angle of repose, which basically means they're as steep as they can be without collapsing under their own weight. Put another way, if you add weight to them, they collapse […]

March 21, 2015

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10:29 PM | Geo 1095: March 20, Day 809: Contact(s)!
There is one very distinct contact in the photo above, between what I've been referring to as the upper unit (lahar deposits), and the lower unit, which, at the time I took the photo, I was assuming were ash deposits of some kind. Turns out, they kind of are, but it's more complicated than I thought, and I only reached a satisfying conclusion a few days ago as to the nature of how they formed.While I would describe the "upper unit" as poorly sorted overall, there do appear to be several other, […]
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9:44 PM | Geo 1095: March 19, Day 808: Miniature Badlands
"Badlands" are a type of landscape that are characterized by deep incision and densely-packed drainage paths. This is a sweet little example, from above the car across to the right side of the photo. First and foremost, what this tells you is that water doesn't percolate into this unit well; it almost entirely runs off. This was established in the previous post, but here we're seeing another consequence of that fact. And since water doesn't get into that unit, it doesn't hold water in such a […]
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6:12 AM | A Time of Our Own: Defining the Anthropocene
In one of the most memorable sequences of his TV show Cosmos, Carl Sagan mapped the entire history of the universe onto a “cosmic calendar.” On this 12-month scale, it took until September for the Earth to be formed, and… Continue reading →

March 20, 2015

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10:06 PM | Iron rain fell on early Earth, new Z machine data supports
Physical tests reveal that, at pressures rivaling those when worlds collide, iron vaporizes at far lower pressures than assumed by theoreticians, explaining why the element is distributed in Earth’s mantle […]
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8:32 PM | Animated Life: Pangea
http://www.nytimes.com/2015/02/17/opinion/animated-life-pangaea.htmlI bet very few people grew up hearing about Alfred Wegener, the man who discovered continental drift. As the son of a geologist, I got to hear the story many times, and he was a huge figure — the man who came to a surprising conclusion that no one believed. I was delighted, therefore, to see him featured in this new piece by Flora Lichtman and Sharon Shattuck for the New York Times Op-Docs series.We’ve picked […]
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5:30 PM | Lava Poured on Ice
I have been a bit heavy on field work and other obligations so a bit short on brilliant content: but this video is way cool. If anything it shows the remarkable insulation ability of basalt. I would note further that the experiment was by Syracuse University - a school I have always been fond of. Syracuse made a nice offer to me to for graduate school. I instead decided to head back to the Washington State landscapes and went to Western Washington University.
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3:45 PM | Leading Theory Of What Causes Ice Ages Cast Into Doubt
The leading theory of what causes ice ages around the world -- changes in the way the Earth orbits the sun- has been cast into doubt by a new study. The study raises questions about the Milankovitch theory of climate, which says the expansion and contraction of Northern Hemisphere continental ice sheets are influenced by cyclic fluctuations in solar radiation intensity due to wobbles in the Earth's orbit; those orbital fluctuations should have an opposite effect on Southern Hemisphere […]

March 19, 2015

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9:36 PM | Kids' Lab at the University of Basel Explores River Science
Dr. Nikolaus Kuhn and Brigitte Kuhn work with students at the Kid's Lab. Photo by Debora Haller.The University of Basel’s Kids’ Lab illustrates the world of natural science to children between 6 and 12 years of age by engaging them in hands-on exploration.Debora Haller is the head of the Kids' Lab. The Physical Geography and Environmental Change Research Group of the University of Basel supports the lab, including Dr. Nikolaus Kuhn, Dr. Wolfgang Fister and Brigitte Kuhn.The […]
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8:40 PM | Subterranean Lava Tubes Should Be Stable Enough For Future Moon Bases
Scientists speculate that massive underground cavities may exist under the lunar surface. And it turns out these so-called "lava tubes" should also be safe enough for a future moon base, according researchers presenting at this week's 46th Lunary and Planetary Conference in Texas. Read more...
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4:38 PM | Field Photos: Landscapes And People Goriganga Valley Kumaon Himalayas
Staggering!... is the word that comes to mind with view of sheer rock faces like this one.The northerly dipping rocks are not sedimentary, but are amphibolite and higher grade metamorphic rocks of the Greater Himalayan Crystalline series (some workers call it the High Himalayan Crystalline series) which make up the hanging wall of the Main Central  Thrust. I hiked through the lower portions of the thrust sheet a couple of weeks ago. The main rock types I encountered were augen gniess, […]
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4:18 PM | How chemistry affects the evolution of life | @GrrlScientist
In this fascinating video, Professor Ros Rickaby from Oxford chats with Professor Simon Conway-Morris at Cambridge about how Earth’s changing chemistry has affected evolution, and how this can sometimes lead to evolutionary convergenceA feature of natural selection, or “survival of the fittest”, is that context defines what is “fittest”. Traits that are “fittest” in one habitat can become liabilities in others. This was observed first-hand across […]
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