Category: geology

Readers’ wildlife photgraphs

February 1, 2015 • 8:15 am

Today we’re stretching the boundaries of “wildlife” again, so that this time it includes geology.  Reader Jonathan Wallace encloses some nice photos of the English coast that give some history:

These were taken from a coastal dune system a little way north of where I live in Newcastle upon Tyne, England.  During the last ice age there was a continuous land bridge across to the continent but this was broken when sea levels rose after the ice melted and there has been continual erosion of the east coast of England since then.  The current coastline was therefore in prehistoric times some distance inland, and the erosion of the dunes at this place revealed a band of peat beneath the sand created through the infilling of a fresh water mire.  Because of the anoxic conditions in the peat, wood and other organic material falling into it were preserved and, as can be seen in the pictures, there are lots of logs and bits of tree branch embedded in the peat and eroding out.  I believe the top of the peat layer has been dated to around 800 BC so a bit less than three thousand years old and the bottom layer is considerably older.  ‘Bog oak’ is commonly dug out of peat workings in Ireland and elsewhere and is often sufficiently well preserved to permit its use as a sought after wood carving material.

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The remains of trees preserved in peat:

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Finally, if you want your ration of critters, here are some lovely photos sent in by a new contributor, Keira from Australia:

Here are ravens from Matilda Bay on the Swan River, Perth, WA [“Western Australia”]:

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A raptor:

Here is a newcomer to the neighbourhood – a hobby falcon [JAC: probably the brown falcon, Falco berigora]. It was really windy and I don’t have a fantastic zoom lens. I think he’s a juvenile looking to establish a territory around here, ’cause he’s been here on 3 occasions.  I’m in the inner city – not at all rural.

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Finally, here’s Keira’s cat, a female named Fattee Cattee,  also described on her website:

I like this portrait of my fluffy girl – she looks very serious:

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Yesterday’s spectacular eruption of Volcán de Colima in Mexico

January 22, 2015 • 10:08 am

Reader Stephen Q. Muth (Butter‘s staff) sent me a link to the Australian Broadcasting Corporation’s video and report of a big eruption of the Colima volcano (Volcán de Colima) in southwest Mexico. It’s erupted several times in the last year, and the Spanish title of the video notes that this eruption happened yesterday. The ABC’s notes:

The active but isolated volcano is located approximately 500 kilometres west of the capital Mexico City and has erupted at least 30 times since 1585.

The vision was recorded on a permanent fixed webcam operated by Webcams De Mexico, which had placed a series of cameras in the area since the volcano’s last major eruptions in 2013 and 2014.

Colima experienced several significant eruptions in the late 1990s and scientific monitoring of the site began two decades ago.

Ash fell on towns up to 25 kilometres away from the volcano, but no lives or properties were under immediate threat.

Note what appears to be a pyroclastic flow moving down the volcano’s flanks. Nothing could survive that avalanche of hot gas and debris.

I’d dearly love to see something like this. I’ve watched the red molten lava from the volcano on Hawaii’s Big Island flow into the sea, making a huge cloud of steam and building up the island, but it wasn’t nearly as dramatic as the video above.

Readers’ wildlife photographs

January 22, 2015 • 7:15 am

Posts will likely be thin on the ground today, as just this minute I’ve received the final galleys of The Albatross and must work on them pronto.  Like Maru, I’ll do my best.

Here are some photos by reader Ken Phelps, which include not just organisms but water in all its forms (except steam).  Identifications are welcome for all of the species; Ken’s comments are indented.

Some very small wildflowers I have not been able to identify. Shot on Quadra Island, B.C.. They were in an exposed mossy area, hugging the ground.

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 Some very fine dew on a rose:

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Mushrooms:

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North America on the left, Europe on the right. The divide in Iceland.

According to this site, Iceland is the only place in the world where one can see the meeting of tectonic plates above sea level.

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I didn’t realize that one could see the meeting of the European and North American tectonic plates in Iceland. You can find a bunch of cool pictures of their junction here.

Arthropod and mollusk (you do know that barnacles are arthropods [crustaceans], right?):

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Ken likes to photograph ice and water, especially waves:

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One of my favorite waves.  A bit of pareidolia in there too. The real thing was about 6″ high, more of a wavelet. Either Fraser or Capilano River water in English Bay, Vancouver, giving it its color.
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A rare video of an exploding volcano

September 7, 2014 • 1:43 pm

Over at Bad Astronomy, Phil Plait has posted a stunning video of a volcano exploding, and gives some background. The eruption was of Mount Tavurvur on the island of New Britain in Papua, New Guinea, and it occurred on August 29th. It was captured on video by Phil McNamara, and is now on YouTube.

Phil’s take:

Holy yikes! The video was taken by Phil McNamara, and posted on his wife Linda’s Facebook page. The volcano has been pretty active historically and has caused a lot of damage; it’s killed many people, and buried the nearby town of Rabaul in ash in 1994. Rabual used to be the provincial capital of the island of New Britain, but after that eruption the capital was moved to another location.

This eruption was smaller in comparison, but holy cow. It was still amazing. In the video you can see lava blasting upward hundreds of meters, falling apparently slowly due to distance. Given the timing delay of the shock wave — 13 seconds or so — so the folks on the boat were just over 4 km away (2.5 miles).

You can see the shock wave traveling down the volcano slope at 00:13, and then ramming the air above the volcano a few seconds later. The sudden compression condensed the water vapor in the air, so you can see ephemeral clouds forming in a rough circle above the explosion. I looked carefully but saw no sign of it traveling across the water.

When you watch the video, enlarge it to full screen for maximum effect.

This video was posted two days ago, and already has more than 3 million views. No surprise!

Here are before and after photos from NASA’s Earth Observatory website: notice all the green that has disappeared. The site also gives a lot more information about the eruption.

Before:

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After:

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h/t: Marcel

The oldest known bit of Earth

February 25, 2014 • 2:09 pm

The Earth is 4.54 billion years old. We know that not from radiometric dating of rocks on our planet, as the oldest rocks haven’t yet been found, but from dating meteorites that fall on earth from the solar system, which formed around the time Earth did.

But of course that’s not fodder for creationist, for we also have old homegrown rocks, clearly showing that the earth is far older than, say, 10,000 years.

And now we’ve found the oldest bit of Earth yet. As ZME Science and a new paper reported yesterday, it’s a zircon crystal from Australia dated at 4.37 billion years.  The paper with the original report is in Nature Geoscience (reference and link below; free download [I think]).

Here it is.

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Photo: University of Wisconsin

And it’s not big:

The geological relic indicates, for one, that Earth’s crust formed shortly after the planet stabilized and formed. John Valley, a University of Wisconsin geoscience professor who led the research, said the findings suggest that the early Earth was not as harsh a place as many scientists have thought.

No doubt, this is an extraordinary find, however, the untrained eye would have surely missed it. Measuring about  200 by 400 microns, or roughly two times the width of a human hair, the tiny gem was luckily retrieved by geologists in 2001 from a rock outcrop in Australia’s Jack Hills region.

The researchers used two ways to check the date: radiometric uranium-lead dating and atom-probe tomography, which uses the actual position of individual atoms in the crystal to check the accuracy of the U/Pb method. I’ll let the readers enlighten us about how this method works, as I don’t fully understand it myself; but the upshot is that the APT dates comport with the uranium lead dates, making hash of the creationist objection that dating methods are unreliable, even in the hands of experts.

The APT was used because of worries that U-Pb dating might be off because lead might have moved within the crystal.  This shows that scientists do know the ways that dating could be off, and have checks for them. And APT showed no evidence of such movement. I’ll show that by simply posting part of the paper’s abstract:

Here we use atom-probe tomography to identify and map individual atoms in the oldest concordant grain from Earth, a 4.4-Gyr-old Hadean zircon with a high-temperature overgrowth that formed about 1 Gyr after the mineral’s core. Isolated nanoclusters, measuring about 10 nm and spaced 10–50 nm apart, are enriched in incompatible elements including radiogenic Pb with unusually high 207Pb/206Pb ratios. We demonstrate that the length scales of these clusters make U–Pb age biasing impossible, and that they formed during the later reheating event. Our tomography data thereby confirm that any mixing event of the silicate Earth must have occurred before 4.4 Gyr ago, consistent with magma ocean formation by an early moon-forming impact about 4.5 Gyr ago

h/t: Ant

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Valley, J. W. et al. 2014. Hadean age for a post-magma-ocean confirmed by atom-probe tomography. Nature Geoscience. doi:10.1038/ngeo2075

Volcanic eruption in Ecuador

February 2, 2014 • 6:43 am

Reader Lou Jost, a biologist who works and lives in Ecuador, sent me a note with some pictures of a huge volcanic eruption that’s occurred near his home. The eruption of Tungurahua is reported at Wired, but Lou sent pictures he took himself, a brief report, and the link to a YouTube video (below). Lou’s comments are indented:

A terrifying sunset yesterday due to a huge earth-shaking eruption of my volcano, Tungurahua. It filled the sky above me. I never saw an eruption this big before. From here in my yard, at 2100m on the volcano itself, it was hard to grasp the size of the ash cloud; it went up 47000 ft! Sulfur dioxide gas made parts of the cloud turn yellow-orange, coupled with pinks from the sunset and gray-black from the dense ash. It looked like a Hollywood movie. I kept expecting Charlton Heston to walk down from the mountain in front of me. I’m so glad I got back from Wisconsin yesterday, just in time to see this. The attached night picture is taken from inside my house near my desk, through a skylight I designed so that I could see the volcano above me.

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A shaky video made by a kid in a city maybe 50km from the volcano, with cute narration:

I don’t speak Spanish, so perhaps a reader can produce a brief translation.

When you see stuff like this, you realize that although humans can do a lot of bad things to this planet, the planet can also do things over which we have no control.

Global warming in action: World’s largest observed glacial calving

February 8, 2013 • 3:39 pm

A “glacial calving” event occurs when a large hunk of a glacier breaks off into the sea. This is normal when glaciers near the ocean move into the warmer waters, but it’s increased dramatically with anthropogenic global warming. Greenland is one of the places that is shrinking rapidly as the glaciers retreat.

Here is a five-minute video showing the largest calving event even seen by humans, and it’s both stunning and saddening. As Slate reports:

Scientists know that Greenland is melting as the earth warms. Studies show that the island has been shedding ice at an incredible pace of 142 billion tons per year—five times faster than the rate as recently as the 1990s. But big numbers in scientific studies about far-off lands don’t always resonate in the public mind, and somehow a substantial portion of the U.S. population still doesn’t believe that the earth is getting hotter.

Over the years, the award-winning nature photographer James Balog grew so frustrated by that disconnect that he decided to dedicate his life to visually documenting the impact of climate change on the world’s glaciers. The documentary Chasing Ice, released in the United States last month, follows his relentless and at-times harrowing quest, which began in 2007 and continues today. The results are breathtaking. Perhaps the film’s greatest achievement is an enormous record of time-lapse images from multiple continents, which allow you to witness glaciers that are hundreds of thousands of years old disappearing from the earth before your eyes.

You can see more about the film “Chasing Ice” here, including a trailer, but have a look at this calving event. The scale of the event isn’t evident until the end, when they impose an image of Manhattan on the ice at about 3:30. But do watch the entire video.

The excerpt above shows the largest glacier-calving ever caught on film. Two young members of Balog’s team camped out for weeks in hopes of catching sight of exactly this. To climate scientists, the colossal event shown above is less persuasive evidence of global warming than the ever-mounting reams of data from ice cores, satellite altimetry, and so forth. After all, icebergs calving from glaciers is a natural process that would happen even if the earth’s temperature were holding steady.

But Balog recognizes that, for most people, believing requires seeing. And here his team succeeded in capturing the awesome effects of climate change in a way that papers published in Science just can’t.

Yep, we’re in huge trouble, and my only consolation is that I won’t be alive to see the real horrors beginning. But the next generation will.

h/t: S.