New Simulations of 1811-1812 New Madrid Earthquakes Show Strong and Prolonged Ground Shaking in Memphis and Little Rock
Heidi Koontz ( Phone: 303-202-4763 );
Computer simulations of earthquake shaking, replicating the quakes that occurred in 1811-1812 in the New Madrid seismic zone (NMSZ), indicate that future large earthquakes there would produce major, prolonged ground shaking. The 1811-1812 events were some of the largest in the United States since its settlement by Europeans, and the NMSZ spans portions of seven states: Illinois, Indiana, Missouri, Arkansas, Kentucky, Tennessee and Mississippi.
Scientists from the Universidad Nacional Autónoma de México, the U.S. Geological Survey, San Diego State University, AECOM (formerly URS Corporation), and the University of Memphis simulated a set of 20 hypothetical, yet plausible earthquakes located along two currently active faults in the NMSZ. The hypothetical earthquake scenarios range in magnitude from 7.0 to 7.7, and consider various possible epicenters.
”Based on our simulations, were the 1811-1812 earthquakes to repeat today, more than 8 million people living and working near the New Madrid seismic zone would experience potentially damaging ground shaking at modified Mercalli intensities ranging from VI to VIII,” said Leonardo Ramirez-Guzman, lead author of the paper that appears in the July 30 edition of the Bulletin of the Seismological Society of America.
“Strong ground shaking in the greater Memphis metropolitan area could last from 30 seconds to more than 60 seconds, depending on the magnitude and epicenter of a potential seismic event,” said Ramirez-Guzman, a professor at Universidad Nacional Autónoma de México and former USGS contract scientist.
The simulations also demonstrate the importance of fault rupture directivity (seismic energy focused along the direction of faulting), especially when combined with the wave channeling effects of the Reelfoot rift, a buried, northeast-southwest trending geologic valley in the NMSZ. In particular, future large earthquakes on the approximately 80-mile long NMSZ fault show strong shaking at vibration frequencies that pose a risk for mid-rise to high-rise buildings and tall bridges. This fault is thought to be responsible for the December 16, 1811 magnitude 7-7.7 earthquake. Some of the earthquake simulations showed strong shaking focused to the northeast as far as 100-200 miles away near Paducah, Kentucky and Evansville, Indiana, and to the southwest 150 miles toward Little Rock, Arkansas. An example of this earthquake shaking focusing effect can be seen here.
While it’s not possible to know which direction a fault will rupture once an earthquake starts, knowing that there is an increased chance of strong shaking along these geologically-defined corridors is a valuable aid in better characterizing seismic hazard and minimizing earthquake risk.
Earthquakes pose a significant risk to nearly 150 million Americans. The USGS and its partners in the multi-agency National Earthquake Hazard Reduction Program are working to improve earthquake monitoring and reporting capabilities via the USGS Advanced National Seismic System (ANSS). More information about ANSS can be found on the ANSS website.Peak ground-motion variability for a magnitude 7.7 earthquake. Warmer colors indicate stronger ground motions. The stronger ground motions are extended further northeast and southwest caused by the channeling effect of the Reelfoot rift (RFR) The fault is displayed as a thick black continuous straight line, with the epicenter indicated by the triangle. (high resolution image 1.3 MB)
USGS Awards $4 Million to Support Earthquake Early Warning System in California and Pacific Northwest
RESTON, Va.— The U.S. Geological Survey has awarded approximately $4 million this week to four universities – California Institute of Technology, University of California, Berkeley, University of Washington and University of Oregon – to support transitioning the “ShakeAlert” earthquake early warning system toward a production stage. A functioning early warning system can give people a precious few seconds to stop what they are doing and take precautions before the severe shaking waves from an earthquake arrive.
The USGS has additionally spent about $1 million to purchase new sensor equipment for the EEW system. These efforts are possible because of a $5 million increase to the USGS Earthquake Hazards Program for EEW approved by Congress earlier this year.
Under the new cooperative agreements, the USGS and its four university partners will collaborate to improve the ShakeAlert EEW system across the west coast of the United States, and will continue to coordinate across regional centers in southern California, northern California, and the Pacific Northwest. The USGS and its university partners will continue development of scientific algorithms to rapidly detect potentially damaging earthquakes, more thoroughly test the system, and improve its performance. In addition, they will upgrade and construct approximately 150 seismic sensors to improve the speed and reliability of the warnings. They will also develop user training and education, and add additional test users. There are currently 70 organizations that are test users, from sectors such as utilities and transportation, emergency management, state and city governments, and industry.
In 2006 the USGS began funding multi-institutional, collaborative research to start the process of testing earthquake early warning algorithms on real-time seismic networks within the USGS Advanced National Seismic Network. Today, the ShakeAlert demonstration EEW system is issuing alerts to the group of test users across the U.S. west coast in California, Oregon and Washington. In California, this is a joint effort, where state legislation was passed directing the California Office of Emergency Services and USGS to partner on development of an early warning system. The new awards will expand the number of end users and is another step to improve the speed and reliability of ShakeAlert.
During the August 2014 magnitude-6.0 South Napa earthquake, an alert was issued providing a nine-second warning to the City of San Francisco. During a May 3rd, magnitude-3.8 event in Los Angeles, an alert was issued 3.3 seconds after the earthquake began, meaning the warning was sent before the secondary, or “S” waves that have the potential for the strongest shaking, had even reached the Earth’s surface. An electronic alert message that travels at the speed of light can outrun the slower earthquake S-waves, providing valuable seconds of warning. Those few seconds of warning can be enough time to stop a commuter train or an elevator, open fire-house doors, stop delicate surgery and “duck, cover, and hold on.”
The plans for ShakeAlert were evaluated by a scientifically rigorous peer-review process: a panel of experts praised the progress achieved and recommended the proposed improvements. The successes of this effective ShakeAlert collaboration among the USGS and the universities led Congress to appropriate $5 million to the USGS in fiscal year 2015 to accelerate the process of migrating towards a public EEW system. In addition to USGS and university partners, the ShakeAlert system involves the participation of state and local governments, end users, and private-sector partners.
The National Water-Quality Tool offers graphical forms of historical and current information about: water quality in the Nation's rivers and streams (top panel); nutrient loading in the tributaries of the Mississippi River (middle panel); and nitrate loads and yields in coastal rivers (bottom panel). (high resolution image)
A new USGS online tool provides graphical summaries of nutrients and sediment levels in rivers and streams across the Nation.
The online tool can be used to compare recent water-quality conditions to long-term conditions (1993-2014), download water-quality datasets (streamflow, concentrations, and loads), and evaluate nutrient loading to coastal areas and large tributaries throughout the Mississippi River Basin.
"Clean water is essential for public water supplies, fisheries, and recreation. It's vital to our health and economy,” said William Werkheiser, USGS associate director for water. “This annual release of water quality information in graphical form will provide resource managers with timely information on the quality of water in our rivers and streams and how it is changing over time.”
Graphical summaries of nutrients and sediment are available for 106 river and stream sites monitored as part of the USGS National Water-Quality Network for Rivers and Streams.
This tool was developed by the USGS National Water-Quality Assessment Program, which conducts regional and national assessments of the nation’s water quality to provide an understanding of water-quality conditions, whether conditions are getting better or worse over time, and how natural processes and human activities affect those conditions.
NORTH LITTL ROCK — Federal officials today estimated more than $6 million in disaster assistance will help fund local governments’ storm recovery from this spring’s severe weather.
That funding is in addition to nearly $2 million in federal disaster assistance to date that has helped individuals, families and businesses repair property and replace essential possessions.Language English
Several of the new US Topo quadrangles for New Hampshire and Vermont now display parts of the Appalachian National Scenic Trail (A.T.) and other selected public trails. Also, parts of the new maps for Connecticut and Massachusetts feature segments of the New England National Scenic Trail as well as sections of the A.T. Further, all of these revised New England maps, to include new US Topo maps for Rhode Island, highlight significant additions to the new quads such as map symbol redesign, enhanced railroad information and new road source data.
“US Topo maps are the ‘gold standard’ for mapped information,” said Fred Dieffenbach, who coordinates environmental monitoring along the A.T. for the National Park Service, “And the inclusion of the Appalachian National Scenic Trail in this latest update illustrates the significance of this prized resource to the American public.”
For East Coast residents, recreationalists and visitors who want to explore the featured New England trails by biking, hiking, horseback or other means, the new trail features on the US Topo maps will be useful.
The Appalachian NST is a public footpath that traverses more than 2,100 miles of the Appalachian mountains and valleys between Katahdin, Maine (northern terminus), and Springer Mountain, Georgia (southern terminus). The Trail winds through scenic, wooded, pastoral, wild, and culturally resonant lands along this ancient mountain range. With more than 99% of the A.T.’s corridor on Federal or State land, it is the longest continuously marked, maintained, and publicly protected trail in the United States.
“The National Park Service has committed significant resources to understanding the environmental health of the lands and resources that characterize the Appalachian Trail along its entire length,” Dieffenbach continued. “It is extremely gratifying to know that its inclusion in the most recent update was a high priority, and clearly validates the efforts of all the people involved with the management of the A.T.”
The New England NST covers 215 miles from Long Island Sound across long ridges to scenic mountain summits in Connecticut and Massachusetts. The trail offers panoramic vistas and close-ups of New England’s natural and cultural landscape: trap rock ridges, historic village centers, farmlands, unfragmented forests, quiet streams, steep river valleys and waterfalls
The USGS partnered with the National Park Service, the Appalachian Trail Conservancy and other organizations to incorporate the trail data onto the updated New England US Topo maps. These two NST’s join the Ice Age National Scenic Trail, the Pacific Northwest National Scenic Trail the North Country National Scenic Trail, Pacific Crest National Scenic Trail, and the Arizona National Scenic Trail as being featured on the new US Topo quads. The USGS hopes to eventually include all National Scenic Trails in The National Map products.
Some of the other data for new trails on the maps is provided to the USGS through a nationwide “crowdsourcing” project managed by the International Mountain Biking Association (IMBA). This unique crowdsourcing venture has increased the availability of trail data available through The National Map mobile and web apps, and the revised US Topo maps.
During the past two years the IMBA, in a partnership with the MTB Project, has been building a detailed national database of trails. This activity allows local IMBA chapters, IMBA members, and the public to provide trail data and descriptions through their website. MTB Project and IMBA then verify the quality of the trail data provided, ensure accuracy and confirm the trail is legal.
These new maps replace the first edition US Topo maps for these eastern states and are available for free download from The National Map, the USGS Map Locator & Downloader website , or several other USGS applications.
To compare change over time, scans of legacy USGS topo maps, some dating back to the late 1800s, can be downloaded from the USGS Historical Topographic Map Collection
For more information on US Topo maps: http://nationalmap.gov/ustopo/Updated 2015 version of the Mount Washington, New Hampshire quadrangle with orthoimage turned on. (1:24,000 scale) (high resolution image 1.1 MB) Scan of the 1893 USGS quadrangle of the Mount Washington, New Hampshire area from the USGS Historic Topographic Map Collection(1:62,500 scale) (high resolution image 1.8 MB) Updated 2015 version of the Mount Washington, New Hampshire with orthoimage turned off to better see the various trail networks. (1:24,000 scale) (high resolution image 1.2 MB)
The National Trails System was established by Act of Congress in 1968. The Act grants the Secretary of Interior and the Secretary of Agriculture authority over the National Trails System. The Act defines four types of trails. Two of these types, the National Historic Trails and National Scenic Trails, can only be designated by Act of Congress. National scenic trails are extended trails located as to provide for maximum outdoor recreation potential and for the conservation and enjoyment of nationally significant scenic, historic, natural, and cultural qualities of the area through which such trails may pass.
There are 11 National Scenic Trails:
- Appalachian National Scenic Trail
- Pacific Crest National Scenic Trail
- Continental Divide National Scenic Trail
- North Country National Scenic Trail
- Ice Age National Scenic Trail
- Potomac Heritage National Scenic Trail
- Natchez Trace National Scenic Trail
- Florida National Scenic Trail
- Arizona National Scenic Trail
- New England National Scenic Trail
- Pacific Northwest National Scenic Trail
Following is a summary of key federal disaster aid programs that can be made available as needed and warranted under President Obama's disaster declaration issued for the State of Vermont.
Assistance for the State and Affected Local Governments Can Include as Required:Language English
WASHINGTON, D.C. – The U.S. Department of Homeland Security's Federal Emergency Management Agency announced that federal disaster aid has been made available to the State of Vermont to supplement state and local recovery efforts in the area affected by a severe storm and flooding on June 9, 2015.Language English
Advice on Preventing Damage from Future Storms Offered at Home Improvement Store in Bastrop County, Texas
AUSTIN, Texas – As Texans rebuild or repair their homes damaged by the May 4 through June 22 storms, the Federal Emergency Management Agency and local home improvement stores have teamed up to provide free information, tips and literature on making homes stronger and safer.
FEMA specialists will be on hand in Bastrop County at in-store information centers to answer questions and offer home improvement tips and proven methods to prevent and lessen damage from future disasters. Most of the information is geared for do-it-yourself work and general contractors.Language English
NORTH LITTLE ROCK – There are only a few days left to meet with FEMA specialsts at select home building supply stores and learn how to lessen the impact of disaster-related property damage.
The experts are available at the stores to talk to any Arkansas resident interested in building or remodeling their property to better withstand heavy rain, wind, and flooding.Language English
NORTH LITTLE ROCK – The disaster recovery center in Howard County will close at the end of the business day on Wednesday, Aug. 5, 2015.
Located at the Carter Day Training Center, 200 Lake Nichols Drive in Nashville, the center was opened to provide help to those whose homes or businesses were affected by the severe storms May 7 to June 15, 2015.
The center is open Monday through Friday, from 9 a.m. to 5 p.m. through Aug. 5. After the center closes, help is still be available online or by a toll-free call.Language English
Disaster Recovery Center in Crawford County to Close Aug. 7; Deadline to Register is Aug. 25.
NORTH LITTLE ROCK – Hours at the disaster recovery center in Crawford County changed this week and officials announced the center will close at the end of the business day on Friday, Aug. 7.
Located at the Arkansas Valley Electric Cooperative Building, 615 E. Pointer Trail in Van Buren, the center provides help to those whose homes or businesses were affected by the severe spring storms, May 7 to June 15, 2015.Language English
Commercial conch waterman arrested for felony tampering reckless endangering numerous fisheries charges
Anti-public lewdness campaign by Parks & Recreation Natural Resources Police nets 12 arrests at Wolfe Neck parking area
Villagers in Kerauja, Nepal standing below a large rock slide that resulted in one fatality. (high resolution image 8.7 MB)
MENLO PARK, Calif. — A new report from the U.S. Geological Survey provides critical landslide-hazard expertise to Nepalese agencies and villages affected by the April 25, magnitude 7.8 earthquake that shook much of central Nepal. The earthquake and its aftershocks triggered thousands of landslides in the steep topography of Nepal, and caused nearly 8,900 fatalities. Hundreds of those deaths were due to landslides, which also blocked vital road and trail lifeline routes to affected villages.
Landslides caused by the earthquakes continue to pose both immediate and long-term hazards to villages and infrastructure within the affected region. Several landslides blocked rivers, creating temporary dams, which were a major concern for villages located downstream. The report provides a rapid assessment of landslide hazards for use by Nepalese agencies during this current monsoon season.
With support from the U.S. Agency for International Development’s Office of U.S. Foreign Disaster Assistance, and in collaboration with earthquake-hazard organizations from both the United States and Nepal, the USGS responded to this landslide crisis by providing expertise to Nepalese agencies and affected villages. In addition to collaborating with an international group of remote-sensing scientists to document the extent and spatial distribution of landsliding in the first few weeks following the earthquake, the USGS conducted in-country landslide hazard assessments for 10 days in May and June. Much of the information obtained by the USGS in Nepal was conveyed directly to affected villages and government agencies as opportunities arose. Upon return to the United States, data organization, interpretation and synthesis immediately began in order to publish a final report.
This new report provides a detailed account of the assessments performed in May and June, with a particular focus on valley-blocking landslides because they have the potential to pose considerable hazard to many villages in Nepal. The results include an overview of the extent of landsliding, a presentation of 74 valley-blocking landslides identified during the work, and a description of helicopter-based video resources that provide over 11 hours of high resolution footage of approximately 1,000 km (621 miles) of river valleys and surrounding areas affected by the earthquakes. A description of site-specific landslide-hazard assessments conducted while in Nepal and detailed descriptions of five noteworthy case studies are also included. The report ends with an assessment of the expectation for additional landslide hazards in the summer monsoon season following the earthquakes.
The full report, USGS OFR 2015-1142, “Assessment of Existing and Potential Landslide Hazards Resulting from the April 25, 2015 Gorkha, Nepal Earthquake Sequence” is available online, as well as the video footage collected during the research.Aerial photographs showing landslides triggered by the April and May 2015 Gorkha earthquake sequence in central Nepal. A, Widespread ridgetop landsliding in Gorkha district. The Kerauja rock slide (cover image of report) is wide scar on ridge visible in photograph background (arrow). B, Partially breached Gogane landslide dam in Rasuwa district of Nepal. Top of scarp below village (arrow) is approximately 400 m above river level. C, Rock falls in the Urkin Kangari Valley, Sindhupalchok district. Image shows approximately 1,200 m relief between top of foreground cliffs and valley floor. (high resolution image 3 MB) Photographs showing the Langtang, Nepal debris avalanche, which destroyed the entire village of Langtang. An estimated 200 people were killed in this single event. A, Oblique northwest view of deposit with cliff in which the debris became airborne. Homes in foreground were pushed over by the ensuing airblast. B, Aerial view of debris avalanche deposit showing location of the Langtang River tunnel through ice and debris. (high resolution image 2.2 MB)
WASHINGTON — As part of the U.S. Department of Homeland Security’s (DHS) ongoing efforts to support state, local, tribal, and territorial partners, Secretary Jeh Johnson today announced final allocations for eight Fiscal Year 2015 DHS preparedness grant programs, including the Homeland Security Grant Program. These allocations total more than $1.6 billion to assist states, urban areas, tribal and territorial governments, non-profit agencies, and the private sector with their preparedness efforts.Language English
OKLAHOMA CITY – Farmers and ranchers affected by the May 5 to June 22 storms, tornadoes, flooding and straight-line winds could be eligible for assistance from several agencies.
The Oklahoma Department of Emergency Management and the Federal Emergency Management Agency can assist survivors who are farmers and ranchers with some immediate needs including grants to pay for:
• Temporary housing and minor home repairs;
• Replacement of personal property, including clothing; and
• Serious immediate needs not covered by insurance.
NORTH LITTLE ROCK – Businesses and nonprofit organizations are discovering a low-interest disaster loan from the U.S. Small Business Administration is smart business.
Disaster loans provide funding for private sector recovery and are being used to:
Repair or replace buildings and business assets, such as equipment and inventory;
Meet payroll and lease obligations during business downtime caused by the disaster;
Refinance existing liens; and
Make improvements to protect against future damage.