kottke.org posts about geology
Volcanoes "scream" before they erupt. And they also have a heartbeat of sorts. Listen to these surprisingly intense sounds emitted by a volcano in Alaska before it erupted. The first recording condenses 10 minutes of audio into 10 seconds, so you can hear the pre-eruption scream:
The second recording is of 10 hours of pre-eruption mini earthquakes condensed into one minute of audio.
The pause right before the eruption is Mother Nature dropping the beat. (via @DavidGrann)
This is an Icelandic waterfall called Litlanesfoss and the naturally occurring rock formation is columnar jointed basalt.
The columns form due to stress as the lava cools. The lava contracts as it cools, forming cracks. Once the crack develops it continues to grow. The growth is perpendicular to the surface of the flow. Entablature is probably the result of cooling caused by fresh lava being covered by water. The flood basalts probably damned rivers. When the rivers returned the water seeped down the cracks in the cooling lava and caused rapid cooling from the surface downward. The division of colonnade and entablature is the result of slow cooling from the base upward and rapid cooling from the top downward.
One of the coolest things I have ever seen. Looks totally fake, like they built it for Fractal Falls in Polygon Gorge at Disneyland or something. Giants Causeway in Northern Ireland looks amazing as well. Check out several similar formations from around the world.
Danxia refers to a "type of petrographic geomorphology" found in China. What that means is you get these mountains that look as though they were decorated with crayons by a five-year-old channelling Dalí.
That shot was taken by Melinda ^..^ on Flickr...you can find dozens of her Danxia photos here. A kottke.org reader suggests that Tiny Wings creator Andreas Illiger was influenced by the Danxia landforms in developing the iconic scenery for the game.
Not a bad theory. (thx, christopher)
Using computer modeling, it's possible to take a crack at answering that question.
If the earth stood still, the oceans would gradually migrate toward the poles and cause land in the equatorial region to emerge. This would eventually result in a huge equatorial megacontinent and two large polar oceans.
Five million years ago, a flood filled the Mediterranean Sea in only two years.
In a period ranging from a few months to two years, the scientists say that 90% of the water was transferred into the basin. "This extremely abrupt flood may have involved peak rates of sea level rise in the Mediterranean of more than 10m per day," he and his colleagues wrote in the Nature paper.
BLDGBLOG has a fascinating interview with geoscientist Abraham Van Luik about how to confine nuclear waste for 1,000,000 years at the Yucca Mountain nuclear waste repository in Nevada. One of the problems is keeping people away from the site in the far future:
We have looked very closely at what WIPP is doing -- the Waste Isolation Pilot Plant in New Mexico. They did a study with futurists and other people-sociologists and language specialists. They decided to come up with markers in seven languages, basically like a Rosetta Stone, with the idea that there will always be someone in the world who studies ancient languages, even 10,000 years from now, someone who will be able to resurrect what the meanings of these stelae are. They will basically say, "This is not a place of honor, don't dig here, this is not good material," etc.
A 35-mile-long rift in Ethiopia will eventually become a new ocean.
Using newly gathered seismic data from 2005, researchers reconstructed the event to show the rift tore open along its entire 35-mile length in just days. Dabbahu, a volcano at the northern end of the rift, erupted first, then magma pushed up through the middle of the rift area and began "unzipping" the rift in both directions, the researchers explained in a statement today.
We should name it Billy. (via clusterflock)
Magnus Larsson has proposed building an ingenious structure in the Sahara Desert: a 6,000 km-long wall of sandstone made by flushing bacillus pasteurii through loose sand. The bacteria quickly solidifies the sand, thereby providing a wall to stop the advance of the desert or even structures for people to live in.
I researched different types of construction methods involving pile systems and realised that injection piles could probably be used to get the bacteria down into the sand -- a procedure that would be analogous to using an oversized 3D printer, solidifying parts of the dune as needed. The piles would be pushed through the dune surface and a first layer of bacteria spread out, solidifying an initial surface within the dune. They would then be pulled up, creating almost any conceivable (structurally sound) surface along their way, with the loose sand acting as a jig before being excavated to create the necessary voids.
This sounds more like sculpting or baking than architecture.
The 2008 election voting patterns in the southern United States followed the big cotton production areas in 1860 which in turn followed the shoreline of the shallow tropical seas that covered the southern part of the US 85 million years ago.
This is not a political blog. However, this is a story I couldn't pass up: the story of how voting patterns in the 2008 election were essentially determined 85 million years ago, in the Cretaceous Period. It's also a story about how soil science relates to political science, by way of historical chance.
Headline I'd like to see in 96 pt. type in the NY Times: Obama Elected By Rich Loamy Soils of Cretaceous Seas.
Human activities can trigger natural disasters such as earthquakes and flooding.
"Dams are the most dangerous man-made structure likely to cause quake," says David Booth of the British Geological Survey. By artificially holding a large volume of water in one place, dams increase pressure on fractures beneath the surface of the earth. What's more, water has a lubricating effect, making it easier for the fractures -- or faults -- to slip.
The sliding rocks of Racetrack Playa.
These rocks can be found on the floor of the playa with long trails behind them. Somehow these rocks slide across the playa, cutting a furrow in the sediment as they move. Some of these rocks weigh several hundred pounds. That makes the question: "How do they move?" a very challenging one.
Includes some nice photos at the end. (via clusterflock)
Geological features called chevrons could be evidence of violent comet/asteroid impacts as recently as 1000 years ago. The chevrons are formed by massive tsunamis; scientists believe one such tsunami occurred in the Indian Ocean 4,800 years ago and was 600 feet high. These impact-caused tsunamis may also be responsible for the various flood myths found in world religions. (thx, matt)
Satellites measuring the earth's gravity from orbit detected a change in gravity from the massive earthquake that caused the tsunami in the Indian Ocean. "The gravity at the earth's surface decreased by as much as about 0.0000015 percent, meaning that a 150-pound person would experience a weight loss of about one-25,000th of an ounce."
Is Taipei 101, the world's tallest building, causing earthquakes? "The considerable stress might be transferred into the upper crust due to the extremely soft sedimentary rocks beneath the Taipei basin. Deeper down this may have reopened an old earthquake fault". (thx, malatron)