The Thistle Landslide

I was recently invited to attend the MYRES 2012 meeting. MYRES stands for “Meeting of Young Researchers in Earth Sciences” This is a “community building effort dedicated to young scientists in Earth Sciences. The effort is centered on a biannual meeting during which various interdisciplinary approaches are presented to try to solve a common geological or geophysical problem.” This year’s theme was “The Sedimentary Record of Landscape Dynamics” and it was organized by a group of very smart/cool/young scientists working for a variety of academic, governmental and private institutions. The meeting was hosted by the University of Utah in Salt Lake City where we spent several days listening to presentations and brainstorming about the future of our respective disciplines. We also spent a lot of time talking about community efforts and how to integrate sub-disciplines to try to solve the ‘bigger questions’ of the source-to-sink conundrum (I’ll be posting more about this later). At the end of the week, we embarked into a wonderful field trip through Utah and my summarizing comment is “there are a lot of exposed rocks in that part of the world.” We were looking at the stratigraphy as well as to modern surface processes and since I have a special passion for all things mass-wasted, I’ll start by sharing with you information about the “Thistle Landslide”.

Thistle landslide, August 2012 (Photo by Lorena Moscardelli)

According to the Utah Geological Survey, the Thistle Landslide was the most costly landslide in U.S. history (at least before 2005): “Record-breaking precipitation in the fall of 1982, followed by a deep winter snow pack, then warm spring temperatures and rapid snowmelt in 1983 set the stage for the Thistle landslide. Once triggered, the slide reached a maximum speed of 3.5 feet per hour and dammed Spanish Fork River within a few days.” You can read more about this landslide here. It’s a really fascinating story since it allows us to appreciate the real impact of geological process in a very human time scale! The other thing that I think is fascinating is the fact that in the equivalent time of “less than a second” (geologic time scale!) this particular process generated a deep scar on the landscape and a deposit that has a good chance of preservation (maybe? partial preservation?). It makes you wonder, how much of the geologic record is dominated by short-termed lived catastrophic processes? I am a catastrophist by nature but I am just saying… 

  

If you want to see more of the geology of Utah download this plug-in for GoogleEarth!

Update:

After I posted this entry, I saw a video of a mudflow that took place last week in Austria - click here to watch video. You will see that the nature of this event is more catastrophic than the Thistle Landslide since the last one only traveled at maximum speeds of 3.5 feet per hour. The original rheology of the failing material has a great deal to do with these differences. Really amazing!