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Friday, December 9, 2016

Great 15-second video of a microburst!

If you know of a better video of a microburst, let me know. This one is great! For more about microbursts CLICK HERE.

8-30-15 - Wet Microburst Chandler Arizona from Monsoon Tracker on Vimeo.

Be sure to check out my new "Montana Hiking Blog" at bigskywalker.com. I try to include some Earth Science with every hike.

Sunday, December 4, 2016

Refraction Caused by a Temperature Inversion

This photo (courtesy of bigskywalker.com) was taken from the Continental Divide trail, about 30 miles northwest of Helena, MT. The valleys were in the midst of a foggy temperature inversion, and a Fata Morgana (superior mirage) was present over the distant mountains. “Fata Morgana” is so-named because it is the Italian name for the Arthurian sorceress Morgan le Fay, and it was believed that she created these illusions of distant castles or land to lure sailors to their deaths. In reality all mirages are due to refraction (bending, redirecting) of light from distant objects - the strange shapes in the photo are the result of light waves from distant mountains being refracted as they traveled through layers of various temperatures (diagram). Apparently the temperature inversion that blanketed the area was one of the factors that allowed the sorceress to do her handiwork. For more about this hike (including many more photos), go to bigskywalker.com.

Wednesday, May 4, 2016

Shonkin Sag Laccolith - Born of Fire and Ice

This cliff in central Montana was formed by two very different events separated by tens of millions of years - a period of volcanism and an ice age. Here, ice age flows of water along the southern margin of the Laurentide Ice Sheet cut into the Shonkin Sag Laccolith, exposing the spectacular cross-section represented by the cliff. Such views of plutonic formations are rare - something normally only seen in textbook diagrams. To learn more click here (site does not open on many mobile devices).

Saturday, December 5, 2015

Time-Lapse of Meandering River (28 years)

Click on THIS LINK to watch a river in Bolivia change over a 28-year period. For more about oxbow lakes, CLICK HERE.

Photo courtesy of NASA

Wednesday, December 2, 2015

Excellent New Climate Change Resources

In response to the climate change conference currently taking place in Paris, some great new resources have appeared. Check out this slick interactive graph (www.bloomberg.com), and then watch the very good video segment below, which aired on PBS Newshour this evening (12/2/15). Here's another - featured on the NY Times site: Short Answers to Hard Questions About Climate Change.