Radar imagery reveal late May thunderstorms blooming along a southwest to northeast line southwest of Fort Collins on the afternoon of May 25. Time lapse imagery facing south captures the drama of north and westerly flow- a bit unusual as most summer storms track east and northeast from the mountains to the plains. Late spring in northern Colorado has brought a lot of moisture- with the threat of stream flooding now and in the days to come. Snowpack in the mountains is still about half melted so a string of warm weather could add to river discharge here and downstream.
If only the rocks could talk…er.. could play a symphony, this is what it would sound like. In honor of the Geological Society of America’s 125th Anniversary, Boulder based-composer and geologist Jeffrey Nytch was commissioned to compose a new symphonic work called ‘Formations’. Mr. Nytch expresses his deep passion for Colorado’s geology as the inspiration for his work in 4 movements. You can read more about this amazing intersection of inspiration, music, and earth science at the Boulder Philharmonic’s website. I owe a debt of thanks to artists like Jeffrey for expressing our natural world in new and exciting ways.
High clouds obscure the lowest path of the sun during this year’s winter solstice. Looking forward to the companion video on June 21.
The NASA satellite AQUA captured this October image of eastern Pennsylvania and its rusty brown-colored ridgelines of the Appalachian Mountains. The NASA website also shows a comparision with the same view from the more ‘summery’ September. Here in in the Colorado Rockies, we enjoy similar October colors at ground level- albeit with less color diversity than our Appalachian counterparts. Aside from the season, what ties both images together are the nature of the ridges- parts of folded mountain belts of different ages. The vegetation here in the foothills of the Rockies flanks the sandstone ridges. In Eastern Pennsylvania, hues of gold, yellow and red deciduous trees cover the ridges. Now to totally confound it all, the age of the Colorado rocks are Pennsylvanian in age.
The video of road damage along Highway 34 from Loveland to Estes Park is amazing. The road was reinforced after a deadly flood in the summer of 1976 that killed 143 people in this canyon. Now, almost a week after the 2013 flood, river waters are receding to reveal destruction among 17 counties- both in the mountains and on the high plains. So far nearly 19,000 homes have been damaged, and over 1,500 have been destroyed. The Colorado Department of Transportation estimates that at least 30 state highway bridges have been destroyed and an additional 20 are seriously damaged, with repairs for damaged bridges and roads expected to cost many millions of dollars. Canyon cutting in the age of human settlement is expensive and deadly.
A few observations about our current Front Range flooding. First, the rain is welcome as the area is still in a moderate drought condition but wow, enough is enough! I measured well over 4.5 inches at my house but south of here- in the Boulder-Longmont area, a few observers reported in excess of 14 inches over the duration of the storm. Second, all the rain was accompanied by mild temperatures and little or very light winds. Not much in the way of downed power lines- though power and cell service were knocked out in many places. Folks from the East or Gulf Coasts who are used to September tropical storms must think it a bit strange. Third, and most meaningful to me are the violent bursts of water rushing down our mountain-front canyons, doing exactly what they do (geologically speaking)—vigorously eroding the land. Unlike historic flood events I can remember, this storm is quite regional, impacting the entire Front Range of Colorado, a corridor of about 150 miles.
Big erosional events like these make me appreciate the power of moving water. The origin of canyons, such as those along the Front Range, are easier to understand if you do the math…. 1 meter of erosion every 1000 years (if this is a true 1000 year storm) in a million years equates to roughly 1,000 meters or more than 3,000 feet of downcutting. Of course, downcutting is an everyday event combined with the fact that the Rockies are still slowly rising albeit at a much slower rate. And, if you’re wondering, the Grand Canyon is about 6 million years old.
Debris flows are a type of landslide where a liquified jumble of earth and plant materials form a fast moving mixture following a rain event, dam breach or rapid snow or glacier melting ( from a volcanic eruption, for example). Here, people anticipated the flow along a dry creek bed and essentially ‘chased’ the event down as a storm chaser would track down severe weather such as an outbreak of tornadoes. Is this safe?…not at all! but what’s so eerie is the way the flow occurs well after the rain storm. This reminds me of the way tsunami waves devastate coastal areas, many hours after large submarine earthquakes generate their initial jolt.
It may not be apparent to many that the first of day of summer (and winter) are truly astronomical events of the highest magnitude. It is the longest (or shortest) day of the year and where the sun’s rays are at their highest angle in the Northern Hemisphere. For many cultures the summer (and corresponding) winter solstice mark either the a start of season or mid-season celebration One interesting observance is from the Atacama cultures in northern Chile where they celebrate the occasion with a ‘take the Sun back’ festival. The cultural reference, in scientific terms, is the apparent reversal of the Sun’s march north and its regression to the South after the Solstice. All of these movements, of course, are a consequence of the earth’s upper (northern) hemisphere tilted toward the sun on June 21– away from the Sun on December 21.
In this way, facing due west at the same spot on my street 6 months later, you can see the sun’s light emanating from its northernmost position (Summer) and its southernmost position (Winter).
Oh my! A new subduction zone is discovered off the coast of Portugal. What does this mean? For fans of Plate Tectonics you can expect the Atlantic Ocean to close- bringing together the North American and European Plates. Don’t hold your breath…the process would take 200 million years.
PBS’s NOVA reports on tornadoes in the wake of the recent deadly storms that devastated Moore Oklahoma and surrounding areas. Why are almost three fourths of the world’s tornadoes located in the US? The unique climatologic and geographic conditions found in the North American midwest account for a great deal of it. The other reason, they offer, is many countries mis-report or don’t report these storms as tornadoes at all. Check it out.