Mi(ni)Geo

If any of you have wondered where the Commonwealth’s...

Mon, 20 May 2013 19:00:35 -0400

If any of you have wondered where the Commonwealth’s beautiful gray granite curbstones come from, today’s photo is the answer: The ~375 Ma (millions-of-years-old) Chelmsford granite. This aerial photo is of the Fletcher granite quarry in Westford, which has been in operation since the mid 20th century. Quarrying of the Chelmsford, and other granites, in Massachusetts has been occurring since the 1600s, according to various town histories.

What is of particular interest in this photo is how well the Chelmsford granite naturally splits at 90 degree angles— something historic granite workers immediately noticed and have taken advantage of over the centuries . The old quarry worker’s term for this is “Rift and Grain”. In New England, the rift and grain of granites, in many places, is oriented in vertically at 90 degrees to one another: in North-South and East-West striking planes: Very convenient for quarrying dimension stone.

The origin of this rift and grain is even more fascinating, and has been the subject of many academic papers over the years including ones by the famous Richard Jahns, Don Wise, and Terry Engelder. The rift and grain are parallel to regional fracture systems in the granite that occurred in response to tectonic stresses in the geologic past— the orientation of those stresses are different than the present day stress in the continental crust of New England (created by pushing from the spreading Mid-Atlantic Ridge). In order to take full advantage of the older rift and grain, quarry operators have to isolate large blocks of the granite and let them “relax” for a few decades so the present-day crustal stress can be removed from the rock. This minimizes wastage and ensures nice, 90 degree angles when the stone is quarried. Photo credit: Bing Maps. (via Massachusetts Geological Survey)

drjerque: Medium sand of the nascent lower Colorado River;...

Sun, 19 May 2013 19:07:24 -0400

drjerque:

Medium sand of the nascent lower Colorado River; early Pliocene-late Miocene(?).

Sigli and Shambe craters in perspective...

Tue, 14 May 2013 22:51:23 -0400

Sigli and Shambe craters in perspective (by europeanspaceagency)

This computer-generated perspective view was created using data obtained from the High-Resolution Stereo Camera (HRSC) on ESA’s Mars Express. Centred at around 18°S and 329°E, this image has a ground resolution of about 20 m per pixel. Sigli and Shambe dominate this image, which highlights the deep fracturing within the crater walls. The shape of the craters leads scientists to believe they were formed from the same impactor, which fragmented into two pieces just before hitting Mars.

Credits: ESA/DLR/FU Berlin (G. Neukum)

romkids: A FEW FINAL THOUGHTS ON CHRIS HADFIELD’S GIFT TO...

Mon, 13 May 2013 21:17:15 -0400

romkids:

A FEW FINAL THOUGHTS ON CHRIS HADFIELD’S GIFT TO EDUCATION, COMMUNICATION & ACCESSIBILITY

You know my love for Chris Hadfield. You can see my first post about him here, “Reasons for Chris Hadfield”.

In my opinion, he is the embodiment of the modern scientist. Someone who is not only a researcher, but a tentpole around which we can build science accessibility and education.

He went up an scientist, but he’s seemingly returned to Earth an icon of education and communication, of which the world has rarely seen.

I honestly don’t even know how I can even go to bed now without a “Tonight’s Finale” photo from Chris of the world.

And with that I want to thank Chris deeply for all that he’s given to us.

I want to also send two special shout outs

To his son, Evan Hadfield, for coordinating all these efforts, and making it possible for us to talk to an astronaut. Up in space. Forever far away, but seemingly closer than most scientists I’ve ever met. Thank you for making this a possibility.

To the Canadian Space Agency, who I could not appreciate more. Exploration of space is not just about discovering the the final fronter, but about realizing what we as humans are fully capable of. Thank you for helping us all experience this.

MEDIA

Above is Chris’ “Space Oddity” cover video which is INSTANTLY the greatest video ever made.

Below is Chris talking about Social Media, something we all know and love.

And HERE is a great article from the CBC on Chris, Evan and the Canadian Space Agency exploration of Social Media in space, and their plans for the future.

jtotheizzoe: How Tall Can Mountains Be? Another great question...

Sat, 11 May 2013 16:17:31 -0400

jtotheizzoe:

How Tall Can Mountains Be?

Another great question that you’ve probably never thought about answered by MinuteEarth.

If mountains were just solid rock on a good footing, then we could have mountains quite a bit taller than what we see on Earth.But because of pesky things like plate tectonics and erosion, we don’t get to have all the nice tall things.

koalite: San Juan, La Union

Fri, 10 May 2013 21:28:31 -0400

koalite:

San Juan, La Union

Satellite radar image from the TerraSAR-X sensor of the summit...

Tue, 07 May 2013 22:15:53 -0400

Satellite radar image from the TerraSAR-X sensor of the summit of Cleveland Volcano showing the summit crater and growth of the lava dome. The summit crater is about 200 meters across. Note that satellite radar images have some inherent topographic distortion due to the manner in which they are collected. Picture Date: August 29, 2011. Credit: Dave Schneider, Zhong Lu, AVO/USGS. (via AVO)

odditiesoflife: Glass Beach, Northern California From 1950 to...

Mon, 06 May 2013 02:49:35 -0400

odditiesoflife:

Glass Beach, Northern California

From 1950 to 1967, residents of Fort Bragg, California chose to dispose of their waste by hurling it off the cliffs above a beach. No object was too toxic or too large such as household appliances, automobiles, and all matter of trash were tossed into the crashing waves below, eventually earning it the name The Dumps. Then in 1967, city leaders closed and reclaimed the beach. Various cleanup programs were undertaken.

Over the next several decades, the pounding waves cleaned the beach by breaking down everything but glass turning the sand into a sparkling, multicolored bed of smooth glass stones. The California Department of Parks and Recreation purchased the land and incorporated it into MacKerricher State Park in 2002.

abcstarstuff: JFAST scientists retrieve temperature data from...

Sat, 04 May 2013 12:33:12 -0400

abcstarstuff:

JFAST scientists retrieve temperature data from Japan Trench observatory

Data will reveal frictional heat generated by fault slip during the Tohoku earthquake

With the successful retrieval of a string of instruments from deep beneath the seafloor, an international team of scientists has completed an unprecedented series of operations to obtain crucial temperature measurements of the fault that caused the devastating Tohoku earthquake and tsunami in March 2011.

Emily Brodsky, a professor of Earth and planetary sciences at UC Santa Cruz, helped organize the Japan Trench Fast Drilling Project (JFAST), which successfully drilled across the Tohoku earthquake fault last year and installed a borehole observatory nearly 7 kilometers beneath the ocean surface. UCSC research scientist Patrick Fulton was on board the research vessel Kairei, operated by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), for the retrieval of the string of pressure and temperature sensors that was installed across the fault zone at about 800 meters beneath the seafloor.

This was the last phase of operations for JFAST, designed to investigate the huge slip (50 meters or more) on the shallow portion of the plate boundary fault that was largely responsible for the Tohoku earthquake and tsunami. The data recovered from the sensors provide a very high-precision record of temperature at 55 different depths across the plate boundary. Many of the sensors also recorded water pressure.

“We will be analyzing the data to characterize the amount of frictional heat on the fault during the Tohoku earthquake,” Fulton said. “We’ll also be closely investigating the effects of other processes within the subsurface, such as groundwater flow and seafloor movement due to aftershocks. It is exciting to finally have this amazing data in hand.”

According to Brodsky, the entire project was unprecedented on many levels. “Nobody had done rapid-response drilling in the ocean, nobody had drilled anything substantial under 7 kilometers of water, nobody had placed an observatory in a fault that deep, and nobody had retrieved a string of instruments from that deep,” she said.

The scientific drilling vessel Chikyu installed the observatory in a dedicated borehole that penetrated 855 meters below the seafloor in a water depth of 6897.5 meters during the Integrated Ocean Drilling Program (IODP) Expedition 343/343T, April-July 2012. Brodsky said the team was very worried after an earthquake occurred in the area in December, raising the possibility of an undersea landslide that could have buried the wellhead of the observatory. So it was a great relief when the instrument string was successfully recovered on April 26, 2013.

The recovered sensors provide data that will be used to determine the frictional heat generated by fault slip during the Tohoku earthquake. Scientists will infer the forces on the fault during the earthquake from these measurements of dissipated energy. The new data are critical to understanding the causes of the large, shallow displacements during earthquakes that can generate devastating tsunamis. The JFAST observatory provides the first temperature measurements at a subduction plate boundary fault immediately after an earthquake.

Fulton described the recovery operation in an email from aboard the Kairei: “Everyone was overjoyed in the Kaiko ROV control room as we started to faintly see the observatory come into view and the words ‘wa suranai 3.11’ we had painted on the side of the observatory, which means: ‘Never forget 3.11,’ the day of the earthquake and tsunami. We then used the ROV robot arms to grab the sensor string and then pull the sensors out of the hole. It was a tense moment and I was extremely uneasy. There was a very strong possibility that the fault may have continued to move, [trapping] our sensor string. It was a few very long seconds until we realized that everything was coming out smoothly and we had probably recovered everything. A few hours later, under a starry night with a lightning storm brewing on the horizon, we had pulled the sensor string onto the boat and confirmed we had all 55 sensors.”

Brodsky and Fulton will be busy analyzing the data over the next few weeks in preparation for the Japan Geoscience Union Meeting, May 19 to 24, when they will present some of the initial results.

TOP IMAGE….Figure shows the drilling site of IODP Expedition 343/343T.

CENTRE IMAGE….Figure shows the temperature sensor assembly in the borehole. Total 55 temperature sensing loggers were installed and successfully retrieved after about nine-month measurement.

LOWER IMAGE….Underwater image shows the top of installed temperature observatory in the borehole on deep seafloor. Image was taken by the KAIKO 7000-II on 26 April 2013.

3-D model of topographic map in northern White Rock Canyon....

Thu, 02 May 2013 23:33:44 -0400

3-D model of topographic map in northern White Rock Canyon. Source: Lite Geology, Number 32, Fall 2012

andrezel: Field map of volcanic regions outside of Flagstaff....

Sun, 28 Apr 2013 01:07:46 -0400

andrezel:

Field map of volcanic regions outside of Flagstaff. This map was compiled from satellite data and is in no way accurate… the idea was to understand how difficult it is to map planets without being on the ground. But pretty, none-the-less.

Pyroxene gabbro (by jvanne) Pyrokseenigabro

Wed, 24 Apr 2013 17:03:41 -0400

Pyroxene gabbro (by jvanne)

Pyrokseenigabro

dazzlingagony: Natural Salt, Precambrian age, mined between the...

Sun, 21 Apr 2013 16:34:42 -0400

dazzlingagony:

Natural Salt, Precambrian age, mined between the valleys of the Indus, in the northern part of the Punjab region of Pakistan.

Aerial view of the San Andreas Fault, Mecca Hills, California...

Wed, 17 Apr 2013 22:46:31 -0400

Aerial view of the San Andreas Fault, Mecca Hills, California (by cocoi_m)

Aerial photograph of the San Andreas Fault near Painted Canyon (at top of image), Mecca Hills, Riverside County, California.

Though less frequent, earthquakes on the East Coast can...

Wed, 20 Mar 2013 21:57:20 -0400

Though less frequent, earthquakes on the East Coast can typically be felt over a much larger area than those with a similar magnitude on the West Coast. The bedrock in California, for example, is fractured, causing seismic waves that travel through it to dissipate faster. In the eastern half of the United States, the bedrock is less fractured and stronger, allowing earthquake energy to travel farther. (via NYTimes)

siwela: Mouse that died in a Russian copper mine and was over...

Fri, 15 Mar 2013 19:54:16 -0400

siwela:

Mouse that died in a Russian copper mine and was over time replaced by Atacamite.

So weird, so cool at the same time.

Desert Roses 2 (by cobalt123) IPhone close-up of a massive chunk...

Wed, 13 Mar 2013 22:28:37 -0400

Desert Roses 2 (by cobalt123)

IPhone close-up of a massive chunk of desert rose, seen at the Flagg Mineral Show in Mesa, Arizona.

ruineshumaines: Paintings by carlybird.

Sat, 09 Mar 2013 01:34:09 -0300

ruineshumaines:

Paintings by carlybird.

themineralogist: Scorodite - Field of view is 10 mm.

Fri, 01 Mar 2013 20:43:10 -0300

themineralogist:

Scorodite - Field of view is 10 mm.

This was the view out the International Space Station’s cupola...

Thu, 28 Feb 2013 21:08:00 -0300

This was the view out the International Space Station’s cupola on Jan. 1, 2013, around 09:37 UTC, looking nearly straight down the gullet of Italy’s Mt. Vesuvius. Perhaps you’ve heard of it? Just a little more than 1,900 years ago, it blew its top in the most famous volcanic eruption in recorded history. About 16,000 people lost their lives that day due to pyroclastic flow—searing hot ash blasting outward from the stratovolcano’s maw.

The volcano has erupted many times since then, including in the 20th century. Got that? It’s still active. Now take another look at that photo, and let the volcano’s surroundings settle in to your mind. It sits just a few kilometers from Naples, and more than half a million people live in the volcano’s red zone—where destruction from a big eruption would be swift and brutal.

That’s why volcanologists consider it the world’s most dangerous volcano. Given all we’ve learned about volcanoes in the past few decades, I hope scientists would be able to give people a few days’ warning about an eruption. Science, after all, saves lives. (via Bad Astronomy)