I’m sorry I did not update last week, I was in the hospital because of food poisoning..On a lighter note I’m sure that everyone remembers superstorm Sandy from last October, well there is some new interesting news about her! Researchers at the University of Utah found that Sandy was seismologically detected. Sandy and other hurricanes can produce micro-seisms ,which are about a 2 or 3 on the seismic scale. There is no actual magnitude scale because storms sit and take many hours while earthquakes strike.
The shaking of the coast was caused by the waves hitting the coast and standing waves that reach the seafloor. One can imagine standing waves as two ripple waves that intersected. Earthquakes arent the only cause of seismic waves. Construction, meteor events, mining, and tornadoes can disrupt the earth enough to do so. Now keep in mind these are seismic waves not earthquakes (which have a whole ‘nother cause). Hurricane Katrina was also recored as far as California!
Scientists have found that they can also track the storms using seismometers. A foundation known as Earthscope has 500 portable seismometers that have been in California since 2004. The purpose of these is to make images of the earths crust and upper Mantle beneath North America. Earthscope has shown evidence of Hurricane Sandy’s presence.
I think this is incredible! Scientists are making amazing progress with seismic technology. We are learning so much more about tsunamis , sinkholes, earthquakes , past events , and soon events! Seismic technology is groundbreaking, well not literally haha.
source and image source:
Image from http://www.sciencedaily.com/releases/2013/04/130403141402.htm
The Rocky Mountain are a western North American mountain range that have distinct crustal blocks. Scientist have been baffled at what was the cause of these 200 million year old blocks. Some scientists believed that the Farallon plate must have acted as a belt that brought fragments towards the American Plate’s margin. The Farallon plate must have subducted underneath the crustal fragments. Scientists debunked that theory because it was not shown on the western coast of South America, since this is a subduction zone where oceanic crust meats a continental plate.
Scientists are not exactly sure what the original and precise source of the blocks could be. Some scientists theorize that they came from volcanic island groups. Scientists Siglock and Mihalynuk have combined findings that were obtained from seismic topography. Siesmic topography allows one to view the earths interior down to the lower mantle. This process was done so that Sigloch and Mihalynuk could analyze how seismic waves are created. Doing this they have created a comprehensive picture of how the accretion process worked.This method shows remnants of ancient techtonic plates and the ocean floor that subducted into the mantle.
Sigloch and Mihalynuk found that the Farrallon plate was small and collided and subducted under the mystery plate. They also found deep sea trenches that outline subduction points. There also is evidence that the former volcanoes created the new material which formed arcs , these arcs explain the blocks.
The American plate moved west and overtook the unknown plate ; that is shown by patterns in the seafloor and can be detected seismologically under the east coast! Amazing! We were on the move and crushing island arcs like a boss! Sorry, I’m a bit too excited..
In 2011 there was a 5.7 magnitude earthquake near Prague, Oklahoma. This is an unusual earthquake because it is linked to wastewater injections instead of techtonic movement. This earthquake was the biggest ever in the state and was felt 800 miles away. The quake destroyed 14 homes and caused damage to US highway 62.
The quake was preceded by a 5.0 magnitude shocks and thousands of aftershocks. Researchers believe that areas were wastewater replenished are filling with oil. Along with that the Wilzetta fault could not sustain the pressure.
With the amount of United States energy production more wastewater is released. This water is used for getting petroleum out of oil wells and a process called hydrofracking. Hydrofracking is a process which cracks rocks to allow them to release natural gases. These methods uses large amounts of water that is contaminated with chemicals and brine and is later pumped back into the ground. Honestly I don’t think that is a wise idea.
These quakes have been found in areas of ground injection in “calm” states such are Ohio and Texas. Scientists say that these midwestern quakes have jumped 11 fold from three decades before! This still has not stopped the processes that cause the quakes . The National Academy of Sciences pleaded for more research to “understand , limit and respond” to these events.
This is a long, yet interesting and compelling article. I implore my fellow classmates to read more and give awareness to this topic..
I chose this topic because of the recent sinkhole in Florida.” A sinkhole is a depression underground that has no natural source of external drainage.” They are usually caused by underground rock that has been dissolved by groundwater. This creates spaces underground .These are softer rocks and salt domes. Other soluble rocks include, gypsum, and limestone and other carbonate rock, this is known as “karst terrain”. Florida’s underground areas are mainly limestone and therefore the state is at a high risk for sinkholes. The hollow land beneath the soil will eventually cave in because it cannot support the land above it. Rainstorms can accelerate the caving in of the land.”
The most damage from sinkholes tends to occur in Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania. It can be difficult for someone to know if they live on suseptible areas. It is recommended that people check their home foundation for cracks and check state or county offices to see what kind of rock they live on.
There are two types of sinkholes; cover-collapse sinkholes and cover-subsidence sinkholes. Cover-subsidence sinkhole form slowly over time when the ground subsides or deflates . These types of events can be less noticeable and go undetected for long periods. Cover- Collapse sinkholes are the most devastating and can develop quickly.
“Sinkhole collapses can range in size and severity. Sinkholes can vary from a few feet to hundreds of acres and from less than one to more than 100 feet deep.” Sinkholes are especially devastating in urban areas. “They can contaminate water resources and have been seen to swallow up swimming pools, parts of roadways, and even buildings.” The visual concept does not leave a pretty image.
People can actually cause sinkholes from leaky faucets to sewer collapse to groundwater pumping. It is very important that we employ proper methods from a small scale to large scale, because the consequences can be deadly.
Here’s a video!
Image From: http://news.nationalgeographic.com/news/2011/11/111111-vikings-sunstones-crystals-navigation-science/
I became interested in this topic because of show called Vikings that premiered on the History channel. This crystal may have been used to help Vikings navigate. This stone is also known as “sunstone” and may have helped locate the sun’s position on cloudy days when a sundial would not have worked. This stone uses polarization which causes the rays to gather in a certain orientation. A piece of the spar was found aboard a British ship that sunk in 1592 named, Alderney.
A physicist named Guy Ropars used a laser light to measure how the crystal seperates polarized light from unpolarized light and found theres only one point where the two beams can be equally strong. Ropars’ team found that the crystal can be used with great precision.
The crystal is a transparent calcite, occurs in cleavable crystals, and has the ability to achieve double refraction. Calcite has a wide variety of color, white streak, vitreous lusters, rhomboidal or perfect cleavage, a hardness of 3 and effervesces when in contact with cold dilute, HCl..Icelandic spar can tell the distance of something and is used in polarizing microscopes. If this was found here imaging what a hiker can do if they get lost! Pretty cool!
Mount Etna is located in Sicily, Italy. Mount Etna is the tallest volcano in Europe and is one of the worlds most active volcanoes. On February 19th the volcano had its first eruption of the year. The volcano is constantly spewing gas or lava but this time the flashes were spotted from space! The ash plumes also went as high as 30,000 feet over the volcano. Etna has also shown shown pyroclastic flows, lahars, and lava.
You can also watch eruptions live at http://www.radiostudio7.it/webcam.asp?web=1&id=1
The NASA Earth Observatory posted an infared image where you can see the lava flow. Images were taken of the summit of Bocca Nuova crater. On February 21st Etna had its fourth paroxysm(short, explosive, and violent bursts ). The crater Bocca Nuova also had is 5th event of the year. The Osservatorio Etneo reports simultaneous activity during eruptions from 1995-2001. This is something to keep in mind, history can repeat itself.
Image from: http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=80479
I chose this topic because it is very interesting and yet no one is talking about it , in fact I hear more about the “Harlem Shake videos”. There is actual footage of this amazing event all over the internet.
On Friday February 15th a meteor exploded over the city of Chelyabinsk, Russia. NASA scientists estimated that the meteor was 55 feet with a 500-kiloton explosion. The rock weighed about 10,000 tons and was traveling at 40,000 mph when it exploded. New estimates were created using infrasound stations that detect bolides, the low frequency sound waves that exploding meteors generate. The meteor entered out atmosphere at 10:20 and outshined the sun. Hours earlier an 150 ft wide asteroid named 2012 DA14 also flew by earth but was not a direct threat. Since the asteroids had different trajectories they were unrelated events. Another fireball occurred February 16th at 7:45 PST near the San Francisco Bay Area.
Scientists have stated that the Russian meteor event is a much more rare occurence. Is 1908 a space rock exploded over Siberia and literally flattened 835 square miled of forest. Scientist Paul Chodas of NASA’s Near-Earth Object Program Office at JPL said “We would expact an event of this magnitude to occur once every 100 years on average. When you have a fireball of this size we would expect a large number of meteorites to reach the surface and in this case there were probably some large ones.”
The meteorite did cause damage by causing a shockwave and raining fireballs. 1,200 people were injured along with smashed windows and damaged buildings. The white trail left behind could be seen as far as 125 miles away. Witnesses say the sound was explosive and the night sky was light as if it were day. The power of the kilotons is similar to a small nuclear weapon explosion.
This Image was also taken from the Reuters website.