American Geophysical Union

Syndicate content
A Community of Earth and space science blogs
Updated: 2 hours 3 min ago

Friday fold: Four folds from VGFC

7 hours 9 min ago
Here are four folds from the Potomac Terrane (or maybe an “exotic unit” that looks like the Potomac Terrane, butted up against the Potomac Terrane) that I saw on the 2014 Virginia Geological Field Conference back in October. It was an overcast, rainy day, so I apologize for the relatively low quality of these images. Happy Friday!

The Mannen rockslide: still standing

10 hours 31 min ago
The Mannen rockslide in Norway continues to actively deform but has not, as yet, failed. There continues to be a great deal of interest in Norway in this event, putting the monitoring team under great pressure

Geomystery: what are these white lines?

Thu, 10/30/2014 - 7:00am
Esteemed readership, I’ve got a mystery for you. What are these white lines, inclined consistently at a high angle to bedding? I picked up this sample below the “Wall of Death,” on the trail from Wapta Lake below Mount Wapta, en route to the Walcott Quarry of the Burgess Shale. The “zebra-striped” rock is of the Eldon Formation of the Cambrian section in Yoho National Park. At first, I thought …

Five Things To Know About 2014 Global Temperatures

Wed, 10/29/2014 - 9:24pm
Deke Arndt at NOAA’s Climate.gov has a good Q&A that is worth sharing. Reproduced below: Five things to know about 2014 global temperatures Author: Deke Arndt Friday, October 24, 2014 Deke Arndt is Chief of the Climate Monitoring Branch at NOAA’s National Climatic Data Center, in Asheville, North Carolina. He is a frequent advisor to Climate.gov, and he’s as good at explaining climate in front of the camera as he is at …

Doppler Radar Sees Debris from Antares Explosion

Wed, 10/29/2014 - 4:25pm
The NWS Doppler radar at Wakefield,Va detected the debris from the Antares explosion Tuesday evening. Not only that, but it was able to show that this was not rain but debris in the air. Being a dual polarimetric radar it can detect the shape of the particles in the radar beam, and a product called the correlation coefficient showed that the echo was made up of particles that were of …

A beefy stylolite

Wed, 10/29/2014 - 7:56am
I saw this large, chunky stylolite this summer somewhere along the trail from Takkakaw Falls to the Walcott Quarry of the Burgess Shale (in Yoho National Park, British Columbia). I like the way weathering has highlighted its form.

Mount Mannen in Norway: an imminent large rockslide

Wed, 10/29/2014 - 2:38am
In Mount Mannen in western Norway, an apparently imminent large rockslide is attracting great media interest, including a live webcam

Antares Explodes At Wallops. Explosion Heard/Seen for 50 Miles.

Tue, 10/28/2014 - 8:08pm
Here is how the explosion looked as WBOC covered the Antares launch and explosion live. This was likely one of the largest rocket explosions ever at Wallops. The reason is that it happened with a fully fueled vehicle, carrying 5,000 pounds into orbit. Most other failures at Wallops were either non-orbital launches, or carrying much lighter payloads. The blast lit up the clouds and was seen across almost all of …

Glacial striations

Tue, 10/28/2014 - 7:53am
Today, I thought I would share some images of lovely “textbook” glacial striations from rocks I saw in the Canadian Rockies this summer…

Sound Science Battles Hysteria- Sagan Got It Right

Mon, 10/27/2014 - 9:27pm
Some politicians (Mainly the governors of NY and NJ) are taking it on the chin this Monday night for locking up a nurse returning from West Africa who was helping patients with Ebola. The treatment of Kaci Hickox has been called a hysterical over-reaction by several of this country’s top health experts, and fortunately they seem to be backing down.  When they locked up a healthy nurse who was helping …

Monday Geology Picture: Peridot at the Smithsonian

Mon, 10/27/2014 - 2:26pm
For this week’s “Monday Geology Picture” I thought that I would share another image from my recent (June 2014) trip to the Smithsonian Natural History Museum. Peridot is my favorite gemstone, and I saw some truly stunning peridot gemstones on display at the Smithsonian. Aren’t they lovely? Here’s a closer view of some of the pretty peridot gems: I’m still in the field, but when I’m back home in a few …

The IAGD: making geology accessible to all

Mon, 10/27/2014 - 9:30am
The IAGD mission is to improve access to the geosciences for individuals with disabilities and promote communities of research, instruction and student support. There is no need to wait to become a member of this organization that led its first accessible fieldtrip one week ago at GSA.

Yamnuska

Mon, 10/27/2014 - 8:46am
Driving west from Calgary, your first evidence of entering the Canadian Rockies’ Front Ranges is the startling sheer cliff of Yamnuska, north of the Trans-Canada Highway: Yamnuska’s shape is a function of differential weathering of the two rock units that make up the mountain: Cambrian Eldon Formation limestone, and Cretaceous shales of the Brazeau Formation. The Cambrian is the uppermost of the two, which is a violation of superposition, considering …

Bedding / cleavage relations in the Stephen Formation, Yoho NP

Sun, 10/26/2014 - 12:43pm
Good afternoon! Here are a few photos, both plain and annotated, showing the relationship between primary sedimentary bedding and tectonic cleavage in the “tectonised Stephen” Formation atop the Cathedral Escarpment (in Yoho National Park), just northeast of the Walcott Quarry where the (thicker, basinward) Stephen Formation hosts the Burgess Shale. Weathering exploits both these planes of weakness… Here, the cleavage is more planar at the bottom of the sample, and …

GSA and the Biggs Award

Sat, 10/25/2014 - 11:24am
The recently-concluded Geological Society of America meeting in Vancouver, British Columbia, was one of my best meetings ever. I gave two talks and a digital poster, supervised three student digital posters and one student group regular poster, attended and contributed to meetings on a variety of subjects, met new colleagues, reunited with old friends, and even attended some stimulating science talks. Plans were hatched, ideas refined, projects discussed. Tuesday was …

Circumzenithal Arc over Maryland

Fri, 10/24/2014 - 5:34pm
The halo near the sun is at 22 degrees, and the bright spot to the left is a sundog (or more technically a Parahelia). Now, Look at the top of the pic, and you see something rather more rare: a CIRCUMZENITHAL ARC. I took the picture (with my newly arrived iPhone 6) just before 5 PM EDT (21 GMT) this Friday evening here in Salisbury,Maryland. The image below from Les …

Friday fold: Three more from the Chancellor Slate

Fri, 10/24/2014 - 11:33am
Remember our examination of buckle folding versus passive folding in the Chancellor Slate (cleaved limy mudrock) of eastern British Columbia? Well, here’s another example: There’s so much awesomeness going on in that image, it’s hard to know where to start. The prominent black thin layers are buckled in a very boxy, asymmetric way. In places, the layer is discontinuous, suggesting faulting or shortening via pressure solution. Note how the cleavage …

Hurricane Sandy restoration saves shorebirds, ‘living fossils’ they rely on

Fri, 10/24/2014 - 9:40am
When Hurricane Sandy hit the U.S. East Coast two years ago, it threatened the survival of a 400-million-year-old crab species and about a million shorebirds that rely on the crabs’ eggs for nourishment during long migrations. Retreating storm waters took with them 60 to 90 centimeters (two to three feet) of sand from the Delaware Bay beaches where horseshoe crabs lay eggs and left behind piles of debris, destroying 70 percent of the crab’s prime nesting zones in the area.

California quake aftermath seen from above

Fri, 10/24/2014 - 9:05am
As Northern Californians picked up the pieces and cooled their nerves on the afternoon of August 24th, just hours after being jostled or lurched from bed by the 3:20am magnitude 6.0 South Napa quake, a satellite an aircraft whizzing by overhead snapped a shot of the scene. Check out some of these remarkable scenes within it that show damage, response, and recovery. The image is now visible in Google Earth, and in Google Maps on …

Riverbank collapse: a fascinating new video

Thu, 10/23/2014 - 3:42am
A nice new video has appeared on Youtube showing a progressive riverbank collapse event, although the location is not certain