Category: geology

Readers’ wildlife photos

February 22, 2023 • 8:15 am

Today we have some lovely geology photos, relating to the early Earth, from reader Rodney Graetz. Rodney’s narration is indented, and you can enlarge his photos by clicking on them:

Pages from the history of planet Earth

The history of planet Earth is recorded by its rocks in the language of their composition and age, and we have only recently been able to read it.  The history is a significant component of human understanding.  It informs us about Early Earth events, such as the origin of Life, and exposes the absurdity of our creation myths.

Here are eleven Australian pages from Earth’s History.

The most interesting pages in Earth’s history are the oldest, for Deep Time is a synonym for Early Earth.  Some Australian landscapes contain old rocks, and one area, The Pilbara, has become an international focus for Early Earth research.

This is a typical Pilbara landscape looking hot and subdued by age.

At my feet was this layer-patterned rock, a fossilised stromatolite – a structure that is recognisable because living stromatolites still exist.  They are the result of a repeated sequence of sticky film-living, bacteria-like life forms being covered by fine sediment, then a new living film is generated and covered, and so on.  The age of this fossilised life is 3400 million years (My),one of the oldest, globally.  The Earth formed at 4543 (My) ago so, the Earth’s age when this stromatolite formed was (4543-3400), or1143 (My).  It took more than a billion years for Life to appear in Earth’s history.

A low conical hill at dawn, topped with an incongruous cap.  It also has that old, subdued look, and rightly so for measurements revealed the cone to be deeply weathered granite aged at 2950 (My), or Earth Age 1600 (My).  The cap rock is of a ‘young’ sandstone of ‘dinosaur’ time, 146-66 (My).

A broken block from a layer of fossilised stromatolites strikingly illustrates its structure, the repetitive layering of life activity and its burial.  Aged as 2740 (My).  Earth Age 1803 (My).

During the period 2470 – 2450 (My), the oceans ‘rusted’.  The soluble (Ferrous, green) Iron compounds were oxidized to insoluble (Ferric, red) form and precipitated out.  The proposed cause was increasing and fluctuating atmospheric oxygen known as The Great Oxidation Event.  The result was this example of Banded Iron Formation (BIF), known globally from many areas of ancient rocks, and the primary source for contemporary iron mining.  Earth’s landscapes, rocks, and soils have been ferric red ever since.  Earth Age 2073 (My).

Leaving the Pilbara, and moving to Northern Australia, this rock is uninteresting in appearance but puzzlingly isolated on a floodplain.  Its measured age is 1800 (My), Earth Age 2743 (My).  Much more interesting is that this outcrop, and the crust it is part of, was once a component of a now-dispersed supercontinent, Nuna/Columbia, located at 30° N, or approximately 5000 km (3000 mi) from where it is today.  The Earth’s crust, in action.

Now to Southern Australia, the Flinders Ranges.  A vertical-up photograph of a rubble-like rock layer overlying a totally different rock type.  The top layer of various sized boulders, gravel and sand is the unmistakable signature of glacial action, that was progressively discovered to be both massive and extensive.  Mapped globally, it was named the Cryogenian Period, 720 – 660 (My), but because it was found to be so widespread over 60 (My), it is thought the entire planet was frozen, the so-called Snowball Earth, or more correctly, Icehouse Earth.  Earth Age 3826 (My).

A ‘golden’ spike that Internationally defines the lower boundary on the geologic time scale.  In 2004, it marked the recognition of a new chapter in Earth’s history.  The beginning (rocks above the marker) of the newly-recognised Ediacaran Period, 660 – 540 (My), containing fossils never before seen.  The rocks below the marker are from the Cryogenian Period.  Earth Age 3883 (My).

The finger points to an unusual rock layer: unusual in that the particles within it are all angular and varied in size.  Interpreted only in 1986, this layer is an ejecta layer from a bolide (meteorite) impact at 590 (My), that created a 50+ kilometre wide crater (20-30 mi) now eroded to a salt lake, Lake Acraman.  This sample of the ejecta layer is about 300 kilometres (190 mi) distant from the crater.  Earth Age 3953 (My).

This fossil-filled rock was formed at 525 (My), Earth Age 4018 (My).  The fossil is an Archaeocyath, meaning ‘ancient cup’.  The circular sections are of a barrel shaped body.  The Archaeocyath are a now-extinct group of marine sponges that were important in forming the first reefs on Earth.  The location of these fossils has been recommended as a World Heritage site.

Back in Northern Australia.  This cliff bordering the Fitzroy River appears unusual in shape, colour, and layering.  Dated at 350 (My), Earth Age 4193 (My), the cliff was once part of a large, fossil-rich, reef.  Known as the Kimberley Fossil Reef, it is horseshoe-shaped and hundreds of kilometres in extent.  Nearby, there are numerous areas of high-quality, fish fossils, the first back-boned animal.  Until then, all land surfaces were lifeless, but from this time on, green (photosynthesizing) plants began invading the land and changing the colour of planet Earth.

Shark Bay, Western Australia, declared a World Heritage site to preserve a large populations of living stromatolites.  This very small sample captures their variation in area and shape, but notice the uniform height determined by tidal variation.  It is a way of living – a signature of Life – that has persisted for at least 3400 (My).  Earth age 4543 (My).

Geological Society of America adds one item to their “rubric” for the Young Scientist Award

February 5, 2023 • 11:30 am

Like many scientific societies, the Geological Society of America (GSA) gives out prizes for scientific achievement. Their awards page lists ten, including the Young Scientist Award, also called the “Donath Medal” after the family that endowed the prize. Here is what the prize is for—contributing to geologic knowledge through your research:

As you see, the criteria are that you have to be 35 or younger and have shown “outstanding achievement in contributing to geologic knowledge through original research that marks a major advance in the earth sciences.”

Apparently, though, this year they added one item to the judging “rubric” (I hate that word) used previously.  Can you guess what that item might be? Stop and think for a second before reading on.

Okay, read on:

Here are the current criteria and evaluation form for the Donath Medal from the GSA’s page. Note that scientific achievement as well a young age are the SOLE criteria for judging the award. But they tweaked “scientific achievement” a bit (bolding is mine):

Overview: Ranking of candidates will consider scientific achievement in contributing to geologic (interpreted to include all Earth science disciplines of GSA) knowledge through original research that marks a major advance in the earth sciences. Significance of scientific achievement and age (<36 yrs) shall be the sole criteria (age evaluated by GSA staff). Appropriate contributions to DEI related to scientific achievement should be considered as an essential part of advancing Earth science disciplines of GSA.

What they’ve apparently done is lumped DEI contributions with real science as a part of “scientific achievement”. You can see that in the numerical evaluation form below. I suspect that a candidate, no matter how impressive their scientific accomplishments, has no chance at the award if they don’t have a decent record of fostering DEI.  This, of course, like the many universities who require DEI statements for hiring or promotion, is a way of turning science into social engineering. Not only that, but a particular and debatable form of social engineering: the creation of equity in all fields of endeavor. And because you must express one point of view to get these prizes, you are the victim of compelled speech.

Characterizing this criterion as part of scientific achievement seems to me clearly duplicitous.  If you’re under 35 and the sole criterion for the award, besides being young, is “scientific achievement”, then you can’t just go tacking Social Justice onto that. DEI efforts, regardless of how much you value them, are not scientific achievements but sociopolitical activities meant to advance an ideological goal.

As Anna commented below (I missed this bit somehow), you can get extra DEI points by “increasing representation of underrepresented groups through their own participation as a member of a URM group. . . “. This means that if you’re a member of an underrepresented minority group, you get extra points just for being who you are. This means it’s easier to win the prize if you’re of a “minoritized” group, making it a somewhat race-based prize.

And this is now the big problem with science. Not only is it being infiltrated by woke ideology to an extent I would have thought impossible, but now that ideology is considered as an essential part of science itself. This is why activists feel empowered to tweak and change scientific truth if it doesn’t comport with their beliefs. One example of this is the pervasive insistence that animals have more than two sexes. (They don’t.) If you can’t see your ideology instantiated in nature, you must find a way to force nature into the Procrustean bed of your ideology.

And you make ideological criteria piggyback on scientific merit. I wonder if the Donath family is down with the new rules. (They’ve also added DEI statements as requirements for other GSA awards.)

Readers’ wildlife photos

July 1, 2022 • 8:00 am

I have a need, a need for photos. Send ’em if you got ’em. Thanks!

Today’s batch (and I may take a hiatus of this feature during the three-day weekend) comes from Matt Young.  His captions and IDs are indented, and you can enlarge the photos by clicking on them.

Four hours in Rocky Mountain National Park. A colleague and his wife were attending a conference in Denver and had a day off, so my wife and I went with them to the park one day in June of 2015. Not incidentally, I also had my (then) new Sony alpha-6000 with a pair of kit lenses, all of which I naturally had to try out.

Here then is the entrance to Rocky Mountain National Park. I confess to having edited out the back of a road sign:

Next, a panorama, just to see if I could do it. The camera is somewhat fussy, and I always seem to scan too fast or too slowly:

A snapshot showing terracing as a result of freeze-thaw cycles:

Glacial cirques, large bowls caused by the action of the glaciers during the Ice Age. The most prominent is on the right, but there are more in the background:

The alluvial fan caused when a dam burst in 1982, burying the town of Estes Park in mud. The fan is beginning to fill in, especially on the right side, but it would not be fair to show an earlier picture:

A yellow-bellied marmot (Marmota flaviventris) running around in the field:

An elk, or wapiti (Cervus canadensis):

Golden-mantled ground squirrel (Callospermophilus lateralis) (not a chipmunk):

Clark’s nutcracker (Nucifraga columbiana), a bird related to jays and crows:

A Clark’s nutcracker perched on a dead tree and demanding to be photographed:

And not to be outdone, a Steller’s jay (Cyanocitta stelleri) perched on a branch:

Readers’ wildlife photos

January 1, 2022 • 8:30 am

This is the second part of a two-part batch of photos by Matt Young (part 1 is here). His IDs and captions are indented, and you can click on the photos to enlarge them.

I was in the Galápagos Islands during the end of December 2005, and the beginning of January 2006, bearing my trusty Canon PowerShot S30, with 3 megapixels and a 3X zoom. I took one or two pictures through an 8X monocular, but other than that I was on my own.

Mammals. The only mammals I saw, other than bipedal, were Galápagos sea lions, Zalophus wollebaeki.

A little snack:

And a nap:

Some geological features. Landscapes.

Lava tunnel. You could have easily crawled inside.

Lava flow.

Impurity.

Stubborn little plant.

Invertebrates. Sally Lightfoot crabs, Grapsus grapsus.

Painted locust, Schistocerca melanocera.

Tourist. Not exactly an invertebrate, but looking kind of spineless at the end of a hot day.

And for good measure, Machu Picchu.

Readers’ wildlife photos

December 10, 2021 • 8:00 am

Do send in your wildlife photos, as I always can use more. Thanks!

Today geologist Robert Seidel has sent us photos of plants and their substrates. His captions and IDs are indented, and you can enlarge his photos by clicking on them.

For your consideration, I’d like to submit some photos of plants growing on geologically interesting stuff. We geologists don’t usually care much for plants since the pesky things tend to cover our outcrops, but they make for nice juxtaposition in pictures like this. I’m not a biologist and so I’m not able to identify all the species; maybe your other readers can help.

Sicilian milkvetch (Astragalus siculus), a plant endemic to the island, on young lava from Mt. Etna. It’s not really visible in the picture, but clumps like this were also crawling with grasshoppers, I assume because the thorns protect them from birds and other predators.

Ferns – I’m not quite sure about the IDs, but I think these are three different species of fern, Hart’s Tongue Fern (Asplenium scolopendrium), Maidenhair Spleenwort (Asplenium trichomanes) and Broad Beech Fern (Phegopteris connectilis) on glacial deposits of the Snowball Earth period, Islay, Scotland. This is the famous Port Askaig tillite, one of the best outcrops from this period around 720 Ma ago, when much of the Earth was frozen.

Thyme – Wild thyme (probably; Thymus serpyllum) on conglomerate from the time of the Messinian salinity crisis, Southern Spain. This was a period ~ 5 to 6 million years ago when the Mediterranean dried up and became a giant salt pan.

Unknown 1 – Unidentified species on gypsum evaporite, also from the Messianian.

Unknown 2 and 3 – Two unidentified species growing on peridotite (an exposed section of the Earth’s mantle) of the Semail ophiolite, Oman.

Lagniappe – quite a few years ago, you posted a recipe for sour cherry pie by your friends Andrzej and Malgorzata. Sour cherries are a bit hard to come by in the UK, but I found that damsons make a good substitute. So many thanks for sharing this recipe, it was delicious!

JAC: If you want Malgorzata’s cherry pie recipe, I can ask her again.

 

Readers’ wildlife photos.

November 24, 2021 • 8:00 am

You know what to do: send ’em in! Thank you.

Today we feature photos of Mount Etna in Sicily taken by Richard Bond. His captions are indented, and you can enlarge the photos by clicking on them.

My photos near the top of Mount Etna might be of interest, though not all of nature is colorful or beautiful or both.

Anyway, from a service complex at 1,900 metres one can take a cable car to 2,500 metres. Previous iterations went higher, but were repeatedly damaged by lava flows, so now a fleet of rather specialised buses goes to nearly 3,000 metres.

The first photo shows one of these: its large wheels, long suspension travel, high ground clearance, and 4WD testify to the difficulty of the terrain. There are no fixed tracks, as new lava keeps changing the upper route.

This shows a fairly recent flow in the foreground with the top of the mountain above it. That bit of white halfway up to the left is steam issuing from a vent. The peaks are a little hazy owing, I think, to dust emitted along with the steam.

This is a close-up of the lava. The whitish inclusions are limestone, carried up from around sea level.

A general view of a crater at about 3,000 metres. It seems to be a complex of one main crater about 300 metres across containing some subsidiary ones. I walked anticlockwise right round this crater, and the next photo looks back to its lowest lip.

The next three photos are of various vents in the sides of the crater, and the fourth one is a mini crater inside the main one.

Mini crater:

This was taken near the highest point of the crater rim. The serpentine track of the bus gives some idea of the steepness and difficulty of the route.

This shows the then highest peak of Etna, 300-400 metres higher, taken as I was walking down from the crater rim. I did not have enough time to walk to the peak. There is a rather neat small crater in the middle ground. Pity about the dusty haze.

Here is one of the numerous boulders scattered around and in the crater, showing embedded limestone. This one was a bit bigger than a rugby ball.

About 30 kilometres from the peak is the delightful town of Taormina. Its main feature is a Greek theatre, which seems to have been deliberately set to have Etna as a backdrop. My photo of it below is most disappointing: I had to use a wide-angle lens setting to include all of the theatre. That not only shrunk Etna but also seemed to exacerbate the obscuring effect of the dust. I include it mainly because I wonder if any of the accomplished photographers among WEIT readers could suggest how I could have done better.

This was taken the following day at Syracuse and shows part of the quarry in which the Athenian troops who surrendered in 413 BCE were worked and starved to death. The rock is limestone, presumably part of the bed that lies under Etna and which is the source of the limestone inclusions.

Readers’ wildlife photos and video

May 22, 2021 • 8:00 am

We have a Saturday potpourri of videos and photos today, with all contributors’ captions indented. Click on the photos to enlarge.

First, a bunneh from Graham Martin-Royle:

As you’re getting short of photos I thought I’d send this one in. Prey animals quite often freeze when they think they’re in danger in the hope that they don’t get spotted (I know you know this, I’m just trying to explain this photo). This rabbit saw my friend and I approaching in this dry gulley in southern Utah, back in 2018 and froze, allowing us to get up pretty close.

Can you spot the rabbit?

Visiting foxes from Randy Schenck:

First, an adult in April:

Jerry,  Foxes in the front yard about 7 am. today.  There were three all together, two adults and one about half grown.  Wish I could have gotten a picture of all three but no luck.  Not a good window looking out front for photos.

This is urban Wichita, Kansas.

So all three foxes were back today, May 1, 2021.  Arrived about 7 am and stayed maybe ½ hour.  This is probably because we put out some food (five big dog biscuits) for the foxes.  The first two photos are of the pup or smaller fox.  The second photo also shows he is carrying one of the dog biscuits.  Having the food out there really did the trick and we will probably try again tomorrow.

A balancing rock from Bryan Lepore:

I am sharing a photo of Balance Rock in Pittsfield State Forest, MA (easy to read about on the Internet). I am sharing this because the rock is amazing, and also because photos I found on the internet are rather weak :

And from Bryan Tarr: a mother and ducklings in Poland. This warms my heart; I wish only that my own ducklings were so well behaved. I count ten.

I had the good fortune to see a mother with her ducklings recently, this time in Radzyń Podlaski near a small stream. I managed to grab my phone just in time to catch the second half of their hurried journey past me.

How tall is Mount Everest?

October 1, 2020 • 1:30 pm

If you asked me the height of Mount Everest, I could tell you without missing a beat: 29,029 feet (I don’t know it by heart in meters, but it’s 8,848 m).  That’s been the accepted height since the 1954 Survey Of India, which established the height using a number of observation stations and triangulation (trigonometry). Since then, there have been a few other measurements, all yielding heights close to the 1954 data: a 1999 National Geographic measurement gave 29,035 feet (seven feet higher), while a 2005 Chinese survey yielded 29,017 (that was the rock height, neglecting the roughly ten feet of ice and snow covering the summit).

There’s no doubt that Everest’s summit is the highest spot on earth measured from sea level (Chimborazo in Ecuador, however, is the highest mountain measured from the Earth’s center), but people want an exact figure. This article in the new National Geographic (click on screenshot) shows the difficulty of actually getting that figure.

First of all, the height of Everest keeps changing, both rapidly and slowly. Slowly because it’s still rising as the Indian tectonic plate collides with the Asian one—the event that created the Himalayas to begin with. That rise is about 0.5 centimeters per year. The more rapid changes are due to earthquakes: one in 1934 is supposed to have lowered the mountain by two feet. Then there’s the decision about whether to count the ice and snow blanketing the peak in its total height, for that blanket can be up to ten feet thick. (Triangulation of course includes that.)

Finally, there’s the tough decision about the baseline, taken as “sea level.” The problem is that calculating “sea level” is hard because it varies from place to place and time to time due to irregularities in the Earth’s shape, and so what they’d like is “what the sea level would be under Mount Everest if there were sea under Mount Everest”.  That involves making two models, as depicted in the figure below from the article, and it’s apparently the sum of the geoid height and the ellipsoid height is the mountain’s height. (It’s a bit complicated, and I can’t say I understand it fully, because sometimes the geoid height looks to be negative.)

The first of two recent sets of measurements were taken by a Nepalese survey team that climbed Everest in 2019, summiting in the middle of the night to avoid the rush of climbers.  Laser trigonometry as well as GPS technology established the summit height. They also used a method to determine the thickness of ice and snow on the summit. That “official” height is now known but hasn’t been revealed, for the Chinese get a say as well: the border between China and Nepal runs right through the summit, and so this spring, when all expeditions were canceled because of the pandemic, the Chinese used a combination of climbers and a surveying plane to get their own height (see below).

And politics are involved as well:

“There’s a lot of history here,” says Ed Douglas, a respected Everest historian who recently published a history of the Himalaya. Douglas notes that, like Nepal, China has long used Everest as a symbol of national identity. In 1960, Mao Zedong ordered a large state-run expedition of Everest. That team made the first successful ascent from the Tibet side of the mountain. During the 2008 Beijing Olympics, China imposed restrictions on climbers on the Tibet side of the mountain so that an official expedition could carry the Olympic torch to the top without incident.

Nepal, one of the poorest nations in Asia, has numerous reasons to keep its wealthy and powerful neighbor happy. During the last fiscal year, some 90 percent of foreign direct investment in the nation came from China, and during his state visit, Xi pledged $500 million in financial aid. This comes in addition to the millions of dollars China has invested in Nepali infrastructure projects, including new airports, railways, and hydropower plants.

There is precedent for Nepal and China coordinating on the issue of Everest’s height. After the Chinese completed their 2005 survey, Nepal and China announced a joint agreement to recognize both the new Chinese survey of the highest point of rock and the 1954 Survey of India elevation, which included the snowcap.

So we’ll have at least two new heights, and they’re very unlikely to be identical. But it doesn’t really matter, as Everest will remain the highest spot on Earth—calculated from an estimated sea level. That’s why I trekked in to see it twice, and why so many have tried, and many have died, trying to stand on the roof of the Earth. It’s a beautiful place to visit, and an excellent trek, and I’m content to not have climbed it. Seeing it was enough, for, believe me, you may think you’ve seen high mountains, but, like Crocodile Dundee’s knife, this is a mountain! I wish I could embed some of the photos I took on my trips, which are on 35 mm Kodachrome slides.

Here are two photos from recent measurement efforts. Photos and captions are from National Geographic:

In 1999 an American expedition put a GPS receiver on the summit of Mount Everest to calculate a new elevation. PHOTOGRAPH BY TRIMBLE

From the recent Chinese expedition:

A member of a Chinese survey team sets up a marker on the summit of Mount Everest on May 27, 2020. With the mountain closed to virtually all other climbers due to COVID-19 during the spring of 2020, China sent an expedition to remeasure the mountain, which is known to Tibetans as Qomolangma. PHOTOGRAPH BY XINHUA, ALAMY

Below is an informative but scary chart from the Encyclopedia Brittanica, showing the peril of trying to climb it. Even I got cerebral edema climbing the small peak next to it, Kala Patthar, which is only 18,519 feet (5,644 m). That, and not base camp, is where you get the view of Everest in all its glory. (You can’t see anything from base camp.)

I made it up and down Kala Patthar on both treks, but the second time I got cerebral edema, wanted to lie down and sleep (my companion stopped me from that, knowing I’d die) and I repeatedly stumbled trying descend. I stopped at the Trekker’s Aid Post nearby for a checkup, and they told me what I had and that it would go away when I descended. (A doctor inhabits a quonset hut during the trekking season.)  I hiked down to 15,000 feet, and then I was fine.

Here, from Wikipedia, is the view of Everest from Kala Patthar. On both days I climbed the small mountain, it was perfectly clear like this, and the view was stupendous. (There was also plume of snow from Everest’s summit, showing high winds.)

h/t: Andrew Berry, a fellow Everestphile

Stunning volcanic eruptions filmed in real time

September 12, 2020 • 2:30 pm

Here we have some pretty amazing shots of the Ecuadorian volcano Reventador erupting between January 5 and 7 of this year, and filmed by Martin Rietze. It’s quite active, and there are two sites reporting the activity (here, and a better one here).  The curious thing is that, as the second site reports, January 2020 wasn’t a particularly active time—even though there were daily explosions! From the second site:

Volcanism in January 2020 was relatively low compared to the other months of this reporting period. Explosions continued on a nearly daily basis early in the month, ranging from 20 to 51. During 5-7 January incandescent material ejected from the summit vent moved as block avalanches downslope and multiple gas-and-steam and ash plumes were produced (figures 120, 121, and 122). After 9 January the number of explosions decreased to 0-16 per day. Ash plumes rose between 4.6 and 5.8 km altitude, according to the Washington VAAC.

Here’s the location:

 

. . . and the YouTube notes, showing it in real time, but during several periods. The noise is amazing, as are the lava flows. At 45 seconds in, you can see the shock wave spreading through the atmosphere before the big blow.

Reventador volcano, Ecuador. Activity documented between 5.-7.Jan.2020. Filming in real time (including nighttime with near full moon). Rare highres material showing vulcanian and strombolian with volcanic lightning and shockwave. Now with real sound! Filmed from observation point in 4,5km distance east of the main summit cone.

If you film it, it’s about 11 seconds from the visible explosion to the sound, or a bit less than 4 km of distance, comporting with the description, though the sound probably started before the large eruption.