Aerial images (collected by USDA and USGS) through time illustrate land use changes and are particularly interesting in areas of urban growth. Additionally, USGS geological information can be overlain to understand the type of rock of sediment in a particular area. The Fish Creek Glacier carved and deposited sediment in the Mountain-area of Steamboat Springs. Morainal Ridges (or depositional push-deposits) can be interpreted from aerial images and ground-truth-ed geology maps. For example, the Anglers neighborhood was built upon glacial push-moraine ridges. Moraines are glacial deposits that are typically hard and unsorted (contain mud-, silt-,sand-gravel- to boulder- sized) sediment that was transported and deposited at the base of the glacial. Push ridges are deposited by episodically surging and retreating glaciers. They can give an indication of the glacial/ climate conditions of that time.

Glacial Geology Maps
Maps illustrating the underlying geology/substrate and development from 1953 to 2017.

On December 11, 2018, the area around Glenwood Springs, CO experienced several earthquakes that ranged from 3.2 to 3.6 magnitude.  According to the USGS and Magnitude – Intensity Comparison, Earthquakes that are in the 3.0 to 3.9 magnitude range area:  “Felt quite noticeably by persons indoors, especially on upper floors of buildings. Many people do not recognize it as an earthquake. Standing motor cars may rock slightly. Vibrations similar to the passing of a truck. Duration estimated.”

A bit about background of earthquakes.  Earthquakes are caused by movements along areas of weakness in the crust called faults.  Earthquakes can be triggered by natural and/or man-made stresses.    Small earthquakes are relatively common in Colorado although Colorado is situated in the interior of the North American Plate.  Earthquakes are most common along the boundaries of Earth’s crustal plates, but can also occur along ancient zones of weakness in the interior of a plate or in areas with active volcanic activity. They can also be induced by human activities such as groundwater/wastewater pumping.  According to the USGS (2010 to 2015 earthquake data) Colorado is ranked 15th of all the states for number of earthquakes with Alaska, Oklahoma, and California ranking, 1,2,3, respectively.  Earthquakes can trigger mass movements and rock falls.

Note in the map, several inferred faults (Grand Hogback monocline) occur in the area of the earthquakes as well as a geologically-active volcano called the Dotsero volcano.  Map of Earthquake Data

 

useful links

As the snow falls and the winter wonderland surrounds the region, thoughts of glaciers come easily to mind.  The North Park Range nestles numerous glacier-carved valleys.  Around Steamboat, Fish Creek, Soda Creek, and Mad Creek are familiar.  For a bit more information see:  http://emerald-mtn-geo.com/steamboat-springs-geology-tidbits/fish-creek-falls-steamboat-and-north-park-mountain-range-glacial-topography/

Happy Winter!

Names Glacial Valleys of the North Park Mountain Range (from Atwood, 1937).