I just got this update from a friend (via LinkedIn):
A new NSF-funded site has just launched. According to the release:
"[The site is] dedicated to cataloging best practices in media-based science education and getting the word out about--and discussing--innovative new media-based science education programs and concepts (where media includes both traditional and new media). The site is located at:
http://www.mediasciencelearning.com/
To celebrate its launch (and help get its discussion areas quickly up to critical mass), the grantees (at their own expense, not NSF's) are giving away Zingerman's gift certificates to the best (and most prolific) contributors to the site's case discussions, located at:
http://www.mediasciencelearning.com/CaseStudies
Related to this, if you know of any great media-based science education programs that ought to be highlighted by this site (or you run one yourself and are looking for feedback, publicity, collaborators, or funders), you can submit it at:
http://www.mediasciencelearning.com/addacase/
"
Showing posts with label geology. Show all posts
Showing posts with label geology. Show all posts
Thursday, January 21, 2010
Sunday, January 17, 2010
Some more useful science online resources
Scivee--share your science online!
SciNet--a new social network for scientists of all stripes, from AAAS.
Periodic Table--interactive periodic table. h/t Staten Island Academy student in ScienceOnline session. (Play with the temperature slider and see how the states of different elements change!)
Miss Baker's Biology Class--some really amazing student projects, blogs, etc.
Staten Island Academy's blog community--a great role model for student blogging.
SciNet--a new social network for scientists of all stripes, from AAAS.
Periodic Table--interactive periodic table. h/t Staten Island Academy student in ScienceOnline session. (Play with the temperature slider and see how the states of different elements change!)
Miss Baker's Biology Class--some really amazing student projects, blogs, etc.
Staten Island Academy's blog community--a great role model for student blogging.
Saturday, January 16, 2010
Some cool science and education web sites, courtesy of ScienceOnline2010
FieldTripEarth--free data, plus info from real, live research programs going on all over the world.
NESCent--the National Evolutionary Synthesis Center. More (lots more) free data, plus educational materials on cutting-edge evolution research. (I think when the speaker demonstrated this, half the room started drooling at the data that are available...)
EduWeb--a source for online/digital, educational games on science, technology, history, and art.
Dryad--another open access data depository.
PRI's The World Science--weekly science podcasts, news stories, etc.
Scitopia--a peer-reviewed-research search engine.
Fold.it--play computer games for SCIENCE!
Spot.us--donate to journalists needing funding to cover their stories.
Science for Citizens--find research projects looking for volunteers.
Pandemic II (game)--play the bad guy. Design germs, infect people, get points!
Science Cheerleaders--learn basic science facts, find citizen science projects, and take a brain makeover quiz!
NESCent--the National Evolutionary Synthesis Center. More (lots more) free data, plus educational materials on cutting-edge evolution research. (I think when the speaker demonstrated this, half the room started drooling at the data that are available...)
EduWeb--a source for online/digital, educational games on science, technology, history, and art.
Dryad--another open access data depository.
PRI's The World Science--weekly science podcasts, news stories, etc.
Scitopia--a peer-reviewed-research search engine.
Fold.it--play computer games for SCIENCE!
Spot.us--donate to journalists needing funding to cover their stories.
Science for Citizens--find research projects looking for volunteers.
Pandemic II (game)--play the bad guy. Design germs, infect people, get points!
Science Cheerleaders--learn basic science facts, find citizen science projects, and take a brain makeover quiz!
Monday, November 30, 2009
Interesting word for today: graben
According to the American Geological Institute's Glossary of Geology, 4th edition, the definition of graben is the following:
"graben (n) An elongate trough or basin, bounded on both sides by high-angle normal faults that dip toward the interior of the trough."
Breaking it down a bit:
A fault is a crack in a rock body along which the rock has moved--i.e., the rock on each side of the fault has moved relative to the rock on the other side. Most faults are tilted relative to Earth's surface--they're not perfectly vertical. Therefore, there is a body of rock "above" the fault and a body of rock "below" the fault. The rock "above" the fault is called the hanging wall. The rock "below" the fault is called the footwall:
The hanging wall and the footwall can move in two different ways. In a normal fault, the hanging wall moves down relative to the footwall. In a thrust fault, the hanging wall moves up relative to the footwall:
A graben is a valley bounded by high-angle (i.e., steep) normal faults on both sides:
Sorry about the blurry images. Blogger's thumbnails aren't that great. But you should be able to see the images in all their glory by clicking on them...
"graben (n) An elongate trough or basin, bounded on both sides by high-angle normal faults that dip toward the interior of the trough."
Breaking it down a bit:
A fault is a crack in a rock body along which the rock has moved--i.e., the rock on each side of the fault has moved relative to the rock on the other side. Most faults are tilted relative to Earth's surface--they're not perfectly vertical. Therefore, there is a body of rock "above" the fault and a body of rock "below" the fault. The rock "above" the fault is called the hanging wall. The rock "below" the fault is called the footwall:
The hanging wall and the footwall can move in two different ways. In a normal fault, the hanging wall moves down relative to the footwall. In a thrust fault, the hanging wall moves up relative to the footwall:
A graben is a valley bounded by high-angle (i.e., steep) normal faults on both sides:
Sorry about the blurry images. Blogger's thumbnails aren't that great. But you should be able to see the images in all their glory by clicking on them...
Tuesday, June 16, 2009
What's the signal, and what's the noise?
As anyone who listens to the (non-satellite) radio knows, signal-to-noise ratio is an important consideration when analyzing a data set. If the ratio is too low, all you get is static. But what if that static actually contained its own signal?
The idea of useful information being "hidden" in apparent noise is nothing new--after all, cosmic background radiation was once thought to be just noise (and for many applications it still is). But in the May 22 issue of Science, Peter Bromirski outlines a rather unusual case of noise-becoming-signal: seismological evidence for climate change.
Geologists use seismographs to record the movements of the crust. Most of the time, the crust doesn't move much, aside from a background "hum" that results from Earth's natural oscillations. That hum can actually show up on seismograms; it has a period of 1-8 minutes or so. Occasionally, though, an earthquake--geologists also sometimes call it a "seism"--causes the crust to move much more emphatically.
During an earthquake, the movements of the crust cause the seismograph needle (or the digital analogue) to move in a specific way. The speed, amplitude, and duration of that motion are related to the motion that occurred to cause the earthquake, as well as to the composition and structure of the materials the resulting seismic waves passed through to get to the seismograph. By studying seismographs from around the world, geologists can infer where and when the earthquake occurred, what caused it, and how the waves it produced traveled. The background hum is just noise, and it's generally ignored.
The thing about seismographs is that, for the most part, they're terrifically sensitive. It's not unusual for them to detect trains and traffic. And, as Bromirski points out, under the right conditions they can also detect ocean waves, particularly those produced by big storms.
During a large storm over the ocean, high winds blow over the ocean's surface. The wind transfers energy to the water, which is where the big ocean waves come from. That energy can generate "microseisms" in the ocean crust. (A microseism is exactly what you'd guess from the name: a very low-amplitude vibration in the crust.) The vibrations produced by wave energy travel through Earth, just like those from an earthquake, and they can be detected on seismographs, too. Therefore, hypothetically, one could use seismogram records to determine the average storminess of the oceans over time.
The use of seismograms to study storminess has a few advantages over more common methods. For one thing, there are accurate seismograms that go back to the early 20th century--as far back as 1930, in some areas. These seismograms were all collected using pretty much the same technology and have similar precision, so they're readily comparable. This is unusual in climate science; many of the techniques commonly used to study recent climate change are fairly...well...recent, so the records don't go very far back or, if they do, they're much less precise.
Another advantage to using seismograms is that the global seismograph network (which has become more and more widespread over time) allows for comparisons between signals from different areas. This can allow scientists to infer the approximate paths and durations of storms in a region. In some cases, microseisms can give information about wave frequency and duration along specific coastline regions, data that may be hard to obtain otherwise.
Some studies using these long-term seismic records do suggest that Earth is becoming stormier: the ambient noise on the seismograms has increased over time.
Some researchers are also studying ways to use storm-driven microseisms to study more than storms. An important use of earthquake seismogram data is the study of Earth's interior. It's similar to the use of ultrasound to see inside the body: just as the path of a sound wave through your body depends on the density and structure of the organs below the skin, so the path of a seismic wave depends on the composition, temperature, and structure of the rock within Earth. Typically, seismologists use earthquake-generated seismic waves to study Earth's interior, because they're very high amplitude and generate strong signals. However, earthquakes are relatively rare and unpredictable. "Background" microseisms produced by storms and wave activity may provide a more long-term and consistent energy source for the study of Earth's interior.
Bromirski, Peter D., 2009. "Earth Vibrations." Science 324: 1026-1027. doi: 10.1126/science.1171839.
The idea of useful information being "hidden" in apparent noise is nothing new--after all, cosmic background radiation was once thought to be just noise (and for many applications it still is). But in the May 22 issue of Science, Peter Bromirski outlines a rather unusual case of noise-becoming-signal: seismological evidence for climate change.
Geologists use seismographs to record the movements of the crust. Most of the time, the crust doesn't move much, aside from a background "hum" that results from Earth's natural oscillations. That hum can actually show up on seismograms; it has a period of 1-8 minutes or so. Occasionally, though, an earthquake--geologists also sometimes call it a "seism"--causes the crust to move much more emphatically.
During an earthquake, the movements of the crust cause the seismograph needle (or the digital analogue) to move in a specific way. The speed, amplitude, and duration of that motion are related to the motion that occurred to cause the earthquake, as well as to the composition and structure of the materials the resulting seismic waves passed through to get to the seismograph. By studying seismographs from around the world, geologists can infer where and when the earthquake occurred, what caused it, and how the waves it produced traveled. The background hum is just noise, and it's generally ignored.
The thing about seismographs is that, for the most part, they're terrifically sensitive. It's not unusual for them to detect trains and traffic. And, as Bromirski points out, under the right conditions they can also detect ocean waves, particularly those produced by big storms.
During a large storm over the ocean, high winds blow over the ocean's surface. The wind transfers energy to the water, which is where the big ocean waves come from. That energy can generate "microseisms" in the ocean crust. (A microseism is exactly what you'd guess from the name: a very low-amplitude vibration in the crust.) The vibrations produced by wave energy travel through Earth, just like those from an earthquake, and they can be detected on seismographs, too. Therefore, hypothetically, one could use seismogram records to determine the average storminess of the oceans over time.
The use of seismograms to study storminess has a few advantages over more common methods. For one thing, there are accurate seismograms that go back to the early 20th century--as far back as 1930, in some areas. These seismograms were all collected using pretty much the same technology and have similar precision, so they're readily comparable. This is unusual in climate science; many of the techniques commonly used to study recent climate change are fairly...well...recent, so the records don't go very far back or, if they do, they're much less precise.
Another advantage to using seismograms is that the global seismograph network (which has become more and more widespread over time) allows for comparisons between signals from different areas. This can allow scientists to infer the approximate paths and durations of storms in a region. In some cases, microseisms can give information about wave frequency and duration along specific coastline regions, data that may be hard to obtain otherwise.
Some studies using these long-term seismic records do suggest that Earth is becoming stormier: the ambient noise on the seismograms has increased over time.
Some researchers are also studying ways to use storm-driven microseisms to study more than storms. An important use of earthquake seismogram data is the study of Earth's interior. It's similar to the use of ultrasound to see inside the body: just as the path of a sound wave through your body depends on the density and structure of the organs below the skin, so the path of a seismic wave depends on the composition, temperature, and structure of the rock within Earth. Typically, seismologists use earthquake-generated seismic waves to study Earth's interior, because they're very high amplitude and generate strong signals. However, earthquakes are relatively rare and unpredictable. "Background" microseisms produced by storms and wave activity may provide a more long-term and consistent energy source for the study of Earth's interior.
Bromirski, Peter D., 2009. "Earth Vibrations." Science 324: 1026-1027. doi: 10.1126/science.1171839.
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