Longtime Denver residents well know that earthquakes here are not unheard of.
From the late 1960s to the early 1980s, small quakes in the Denver area were relatively common. The majority of those have been attributed to the injection of liquid waste into the Earth out at the Rocky Mountain Arsenal.
Similar manmade processes are believed to be the source of recent earthquake activity in Oklahoma and possibly the earthquakes seen in May and June of this year near Greeley.
Southern Colorado near Trinidad routinely sees small earthquakes. Some of the activity there may be related to mining. However the area is also home to the Northern Sangre de Christo Fault and the Southern Sawatch Fault, both of which have been sources of activity in the past.
Looking farther back, it was on November 7, 1882 that the largest known quake in the state’s history occurred. A temblor estimated at magnitude 6.6 struck near Rocky Mountain National Park. Contemporary news accounts of the day indicate damage was seen in Boulder and the quake was felt as far away as Salina, Kansas and Salt Lake City, Utah.
For four decades Landsat satellites have beamed back amazing pictures of the Earth from their perch far above the planet’s surface. The latest craft in the series was launched last month and among the first images it captured were pictures of the area around Fort Collins and the Galena Fire burn scar.
The Landsat Data Continuity Mission took to space on February 11 to continue the joint program between NASA and the USGS. This latest spacecraft has some of the highest resolution imagery devices of any Earth-observing satellite and will allow the agencies to monitor the natural and human processes taking place on the planet.
This week NASA released some of the first images from the new craft including its ‘Image of the Day’ from the Earth Observatory program on Thursday. The photos capture the northern Colorado Front Range in natural color and one showing wavelengths of light not seen by the human eye. The city of Fort Collins is clearly seen as is the Galena Fire burn scar west of Horsetooth Reservoir.
Below the images are further explanation from NASA.
Made with reflected red, green, and blue light, the image from the Landsat Data Continuity Mission shows Fort Collins as the human eye would see it. (NASA)The image from the Landsat Data Continuity Mission shows the Fort Collins area in wavelengths of light not usually visible to people. Plants are green, city areas are purple, snow is pale blue, and bare earth is tan-pink. . (NASA)
From NASA:
On March 18, 2013, the newly launched Landsat Data Continuity Mission (LDCM) began to send back images of Earth from both of its instruments—the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). This view of Fort Collins, Colorado, is among the satellite’s first images.
The images above are close-up views from the OLI sensor at its maximum resolution of 15 meters per pixel. The top image displays natural color, while the second image blends shortwave infrared, near-infrared, and green wavelengths (LDCM bands 7, 5, 3). The close-ups were cropped from larger Landsat scenes (downloadable beneath each web image) that show where the Great Plains meet the Front Range of the Rocky Mountains in Wyoming and Colorado.
“The first OLI and TIRS images look great right out of the box,” said Jim Irons, LDCM project scientist. “I have waited a long time to view the first LDCM images and I could not be more impressed with their appearance.”
Made with reflected red, green, and blue light, the top image shows Fort Collins as the human eye would see it. The city is a gray grid surrounded by the curving roads and brown yards of residential neighborhoods. White clouds cast black shadows on the ground below. Land freshly burned in the Galena fire is charcoal black—just slightly darker than the dark green coniferous forest to its west.
The second image shows Fort Collins in wavelengths of light not usually visible to people. Plants are green, city areas are purple, snow is pale blue, and bare earth is tan-pink. This combination of visible and infrared light reveals features of the landscape not otherwise visible. For example, irrigated parks, yards, and golf courses are bright green in this image, but brown in natural color. The Galena Fire burn scar is dark red and easy to distinguish from its surroundings.
The Landsat Data Continuity Mission was launched on February 11, 2013, to continue the four-decade-long Landsat record of Earth’s landscapes. LDCM represents an evolutionary advancement in technology from previous Landsat sensors, collecting more data daily and with greater fidelity. The imagers also include two new bands to improve the view of clouds and near-shore waters.
LDCM’s normal operations are scheduled to begin in late May 2013, after the instruments have been calibrated and the spacecraft has been fully checked out. At that time, NASA will hand over control of the satellite to the U.S. Geological Survey, and the satellite will be renamed Landsat 8.
Satellite imagery released by the USGS and NASA (below) shows the scar the EF3 tornado left on the earth as it ripped a path 39 miles long. The image taken by Landsat shows the path of the half-mile wide tornado as it cut through Sturbridge and beyond.
The twister first touched down near Westfield and then moved into Springfield after crossing the Connecticut River. Both areas saw extensive damage to buildings and homes as the twister moved through.
As it moved east the tornado debarked trees and struck the town of Monson where extensive damage was seen. It eventually hit Brimfield Sate Forest and then the Southbridge Airport.
When it was done, four people were killed and 200 injured. Latest estimates put the damage cost at $90 million making it the most costly natural disaster in the state’s history.
Two smaller, EF1 rated tornadoes also struck nearby on the same day. One caused a damage path 3.6 miles long and the other 1.3 miles long.
Image taken by the Landsat satellite on June 5, 2011 showing the damage path from an EF3 tornado that struck Massachusetts on June 1, 2011. Click the image for a larger version. (USGS / NASA)
A 'super storm' like one that struck California 150 years ago would flood an area hundreds of miles long. (USGS / Google Earth)
California and earthquakes go together like coffee and a cup but a new study suggests that an entirely different kind of disaster may have a bigger impact. The U.S. Geological Survey gathered 117 scientists to evaluate a hypothetical – but possible – “super storm” and its impact on the Golden State.
At the end of 1861 and into the beginning of 1862 a very wet Pacific storm inundated California with rain. This storm turned much of the Sacramento Valley into an inland sea and flooded an area hundreds of miles long.
Today, California is the United State’s most populous state and it has the equivalent of the eighth largest economy in the world. The study shows that if a similar storm were to occur today the result would be disastrous.
The implications of this disaster scenario are tremendous and stretch far beyond California’s borders. Further, one has to wonder ‘what if’ Thornton and the Denver area were presented with a similar scenario?
A magnitude 5.0 earthquake struck north of Anchorage, Alaska on Wednesday evening. (USGS)
Alaska is one of the most seismically active parts of the United States and early Thursday morning residents near Anchorage received a reminder of that fact. A magnitude 5.0 temblor stuck in the evening hours on Wednesday and was felt across the south-central area of the state.
Centered 50 miles north-northwest of Anchorage, the quake struck at 07:15pm and according to the U.S. Geological Survey (USGS) was at a depth of 12.9 miles below the surface.
The service said it had received reports of the temblor being felt as far away as Palmer and Valdez to the east and Skwentna to the west. Residents of Anchorage and Seward to the south also felt the shaking.
Being along the Pacific Ring of Fire, Alaska regularly experiences earthquakes although most are small and not felt. The boundary of the North American and Pacific tectonic plates that runs through south-central Alaska and the Aleutian Islands is where most of the activity occurs.
The Alaska Earthquake Information Center (AEIC) says that the state receives from 50 to 100 earthquakes a day. Three of the 10 largest earthquakes recorded in the world, all larger than magnitude 7.9, have been recorded in Alaska.
Also new is our Wildland Fire Activity page that shows an integrated Google Map of all recent major wildland fires in the continental United States. You can click on any incident to get more details. Below the map is the latest wildland fire news from FireHouse.com. In light of the recent fires in California, this is a timely addition. Special thanks to one of our regular visitors, David Canfield, for this suggestion.
Both items are now available under the Almanac menu item on the left.
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