Show this to your students and see if they can figure out what caused it. The Gallatin River joins with the Madison and the Jefferson near Three Forks, MT to form the Missouri River. To learn more about ice jams, CLICK HERE.
To view a convenient list of all the resources that have been posted on this "Earth Science Guy" blog site, CLICK HERE.
This week's resource is a "virtual field trip" to a butte located in central Montana. Crown Butte is a laccolith that formed over 70 million years ago, and has been exposed by erosion. The butte and surrounding area feature examples of the following: columnar jointing, igneous rock in layers (layered igneous complex), a beautiful porphyry, lateral dikes, and a nearby extinct volcano. The photo on the right shows the porphyry that Crown Butte is made of. The large augite crystals formed before the molten rock moved from the magma chamber into the laccolith.
For a short preview, watch the PowerPoint presentation below, and then CLICK HERE to access the "virtual field trip". Here is the WORKSHEET (pdf file) that students will do as they use the web site. Another version of the worksheet is also available on the web site.
To view a convenient list of all the resources that have been posted on this "Earth Science Guy" blog site, CLICK HERE.
Below: When it comes to greenhouse gases, methane is often overshadowed by carbon dioxide. Your students will remember methane after they see this 2-minute video. Be sure to watch the last 30 seconds!
Below: This is a segment from the documentary, "Chasing Ice", which I watched a couple weeks ago. I highly recommend that you see it on the big screen. The imagery is amazing!
To view a convenient list of all the resources that have been posted on this "Earth Science Guy" blog site, CLICK HERE.
Anyone who teaches Earth science knows that density differences play an important role in many Earth systems. This (see video above) is one of the most clever demonstration of density that I've seen in quite some time. The mystery liquid is vegetable oil. Thanks to Rick Dees of Huntley Project High School for sharing it.
Coming on Friday, February 15 . . .
(unrelated to density) An asteroid, 50 m in diameter, will pass within 21,000 miles of Earth. Watch this 4-minute NASA Science Cast video to learn about the details.
One more thing . . .
This week's NOVA looks like it might be pretty good. The two-hour special, titled Earth from Space, airs Wednesday evening, February 13 on PBS.
To view a convenient list of all the resources that have been posted on this "Earth Science Guy" blog site, CLICK HERE.
The first 3 minutes of this video show how to do the activity. The final 4 minutes are highlights of my students doing the activity. CLICK HERE to read the guidelines, and gain access to a PowerPoint and a student handout.
Hidden heat . . .
Most people understand that storms transport moisture from the oceans to continents. But, another important aspect of storms, often over-looked and not well-understood, is that they transport heat as well. It's easy to convince students that water molecules in those snow-flakes falling outside evaporated from the ocean a few days ago, however convincing them that storms transport heat is a tougher sell. Actually, the two (moisture and heat) are closely related. As water molecules evaporate from the ocean, they absorb heat in order to make the phase change. Then, as that vapor changes back into liquid droplets in a hurricane or ice crystals in a winter storm, this heat is released into the surrounding air. Called latent heat, this is the "energy" that fuels hurricanes and the warmth of Chinook winds, and it plays an important role in microbursts and other interesting things that happen in the real world.
Seeing is believing . . .
The best thing about this activity is that students actually get to watch the temperature of water rise dramatically as water freezes right before their eyes! They will use a beaker of salty slush to supercool (-5) two test tubes of water. Then they will "trigger" the freezing. As the water molecules change from liquid to ice (within seconds), they release latent heat. This causes the temperature of of thermometers in the water to rise (also within seconds). The show doesn't last long, but it is pretty cool to see the surprise on students' faces as they watch it happen.
To view a convenient list of all the resources that have been posted on this "Earth Science Guy" blog site, CLICK HERE.
This 4-minute video explains the challenges of predicting earthquakes in the short-term.
To view a convenient list of all the resources that have been posted on this "Earth Science Guy" blog site, CLICK HERE.
Many people think that sunlight reflecting off of ice at the poles causes the northern lights. This is not true! The true cause of the lights is a combination of three factors - the solar wind, Earth’s magnetic field, and the atmosphere.
The solar wind . . .
The sun is constantly emitting charged particles (electrons and positive ions). This invisible "wind" of particles, called plasma, varies in intensity depending on how active the sun has been. If there is some sort of flare or other type of "storm" on the sun, the solar wind becomes stronger.
Earth's magnetic field . . .
We are protected from the harmful effects of the solar wind by Earth's magnetic field. The magnetism of our planet forms an invisible shield represented by the blue lines (pipe cleaners) on the model above.
Earth's atmosphere . . .
As the solar wind encounters our magnetic field, the lines guide some of the charged particles down toward the Earth. As the particle enter our atmosphere, something similar to what happens in a fluorescent light bulb takes place. The charged particles "energize" gases in the atmosphere, causing them to emit light. The normal position of the auroral oval is far to the north of us. The city best positioned to see the light show may be Fairbanks, Alaska. As long as the night is dark and clear, there is a very good chance that residents of central Alaska will see the lights. A similar ring of light exists near the Magnetic South Pole (the southern lights; Aurora Australis).
So what does it take for us to see the lights in the "Lower 48"? . . .
In order for the oval to be present at lower latitudes, there must be some sort of storm on the sun. If such a storm causes a burst of solar wind (coronal mass ejection) this can disrupt Earth's magnetic field, causing those invisible lines of magnetism (blue lines on model) to enter the Earth much farther to the south of their normal position. This happens more often during a "solar maximum": a year when the sun is especially active. The last solar max occurred in 2001 and the next is expected in the Autumn of 2013.
To learn more, here are few more resources:
1. Aurora FAQs
2. Montana Earth Science Picture of the Week
3. The Solar Max is Coming!
4. Aurora Forecast Page
To view a convenient list of all the resources that have been posted on this "Earth Science Guy" blog site, CLICK HERE.
