Forces that Shape Planets

Rain (and Erosion) is One of Them

Back in graduate school I took some geology and planetary science classes where were studied the forces that shape the planets as we see them today—in particular the rocky ones. Every geology student learns that volcanism, tectonism, and weathering are major processes that sculpt planetary surfaces. Volcanism is volcanic action. It expresses itself from volcanoes, like those we see in Hawai’i or Washington, Japan, Indonesia and other hotspots on our planet. Tectonism is most easily thought of as the process that builds mountains, moves plates of material around, and creates fractions in the rocky mantle of our world. Weathering is the process by which water and wind shape the surface. Wind erosion is called aeolian weathering.  Water erosion takes place through the action of running water over a surface.

My area of the world has been subject to the most intense water weathering the past few days and the results are truly disastrous. The Front Range of Colorado (so named because it lies along the front range of the Rocky Mountains) has received upwards of 14 or so inches of rain in only about 2-3 day’s time. To put that into perspective, this is just under our YEARLY expected total of ALL moisture (including snow).  To get it in the space of a few days is truly amazing. And, when you get that much water all at once, devastation occurs.

Experts estimated that the Boulder, Colorado area received about 4 BILLION gallons of water in a very short time. That includes the mountain areas.  Where does all that water go?  In the mountain, it goes downhill. As it does, it picks up speed, plus debris. And by debris, I mean trees, telephone poles, cars, branches, houses, and big boulders—whatever happens to get in the way of the wall of water-borne debris. The destructive power of water moving down the  mountains has torn up roads, homes, towns, and highways. It has upended people’s lives. And it has taken some of those lives.

As I type this, estimates of the missing and unaccounted for people in the towns of Boulder, Estes Park, Lyons, Jamestown, Salina, Big Thompson Canyon, Longmont, and many other communities is up to around 1,200. These may include people who just haven’t had a chance to call and tell someone they’re save, but at least four people HAVE died in this disaster. There will likely be more.

The scenes of devastation, like the one above, are just unbelievable. They include houses hanging over crevasses, cars buried in mud and upended like toys. Scenes of flooded fields greet people on the plains east of Boulder, Greeley, Fort Collins and Longmont. In Denver, there are images of cars left abandoned in flooded intersections, flooded yards and neighborhoods, and debris everywhere. (You can see more images at on the Denver Post’s Web site).

Living on an active planet is not always easy. People who live with volcanoes know this very well. If you live in a seismically active area, such as along the San Andreas Fault in California, you know what it’s like to live with the knowledge the next big quake is coming. People who more regularly live with monsoon rainstorms know what it’s like to endure flooding. And now, people in Colorado know what it’s like to have the same very unseasonal monsoons hit our region. These floods are being called 100-year and 500-year floods, so named for the statistical frequency with which they can happen. Clearly they dont’ happen every year. The last big floods I recall were in the 1960s, but even those were not as destructive as the past few days have shown us. And, prior to these latest rains, our area had been getting higher than normal rain fall–unusual for a region that normally gets 15-20 inches a year. So, why did this happen?

There is already knowledgeable talk of climate change playing a role in bringing these rains to our region. As our climate changes, weather extremes become more… extreme. Weather that was once rare in a region is now becoming more commonplace (such as the Arctic warming destroying the sea ice). Warm rains this late in Colorado are not the norm. Scientists are now seeking to understand why we got them. There is an excellent discussion of this very topic, called Inside the Colorado Deluge, published on the blog of the National Center for Atmospheric Research in Boulder, and worthy of reading.

One thing I do know is that these rains and floods are not part of divine retribution or magical spells or anything that smacks of the occult or weird or because there’s gay marriage or women’s lib or atheists or or whatever it is that short-sighted and ignorant people like to blame these things on.

These floods happened because we got a lot of rain, and rainwater does what it does under the force of gravity on a rocky planet with an atmosphere and weather. There are scientific explanations for what has happened.  And, there are psychological reasons why us humans and our animals are devastated by what has happened and we seek to understand and cope with such disasters. Knowing the science behind these happenings helps me, at least, to cope with them. I hope it does for others, although I know that such knowledge will in NO way bring back a lost loved one, a lifestyle, a home, a pet, or a livelihood.

We live on an active planet, in every sense of the word. Lava, earthquakes, rain, snow, and unseasonal weather are part of the gig here. We humans get too comfortable sometimes and forget that our friendly, life-giving planet also presents us with challenges and tests. And how we survive those challenges and tests are part of the lesson we learn as we live here.

Please keep those who have lost their lives, homes, and livelihoods in this disaster in your thoughts. And, if you can send along help, the Red Cross and regional blood banks will be happy to talk to you. The Denver Post has a story about how people can help; check it out.