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Laboratory Study Shows Future Generations of Fish Affected by Endocrine Disruptor Exposure

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Mar 24, 2015.

Summary: Fish exposed to the endocrine-disrupting chemicals bisphenol A (BPA) or 17a-ethinylestradiol (EE2) in a laboratory have been found to pass adverse reproductive effects onto their offspring up to three generations later, according to a new study by the U.S. Geological Survey and the University of Missouri

Contact Information:

Jennifer LaVista ( Phone: 303-202-4764 ); Donald Tillitt ( Phone: 573-876-1866 );




Fish exposed to the endocrine-disrupting chemicals bisphenol A (BPA) or 17a-ethinylestradiol (EE2) in a laboratory have been found to pass adverse reproductive effects onto their offspring up to three generations later, according to a new study by the U.S. Geological Survey and the University of Missouri.

Aquatic environments are the ultimate reservoirs for many contaminants, including chemicals that mimic the functions of natural hormones. Fish and other aquatic organisms often have the greatest exposures to such chemicals during critical periods in development or even entire life cycles.

Scientists exposed fish to either BPA or EE2 for one week during embryonic development, while subsequent generations were never exposed. Future generations showed a reduced rate of fertilization and increased embryo mortality. The full study, published in the journal Scientific Reports, is available online.

“This study shows that even though endocrine disruptors may not affect the life of the exposed fish, it may negatively affect future generations,” said USGS visiting scientist and University of Missouri Assistant Research Professor, Ramji Bhandari. “This is the first step in understanding how endocrine disruptors affect future generations, and more studies are needed to determine what happens in the natural environment.”

There were no apparent reproductive abnormalities in the first two generations of fish, except for two instances of male to female sex reversal in adults of the EE2 exposed generation. Findings show a 30 percent decrease in the fertilization rate of fish two generations after exposure, and a 20 percent reduction after three generations. If those trends continued, the potential for declines in overall population numbers might be expected in future generations. These adverse outcomes, if shown in natural populations, could have negative impacts on fish inhabiting contaminated aquatic environments.

This study examined concentrations of EE2 and BPA that are not expected to be found in most environmental situations. However, concerns remain about the possibility of passing on adverse reproductive effects to future generations at lower levels. At this time, the ability to evaluate mixtures of estrogenic chemicals working jointly is limited. 

The scientists studied BPA and EE2 because they are chemicals of environmental concern and represent different classes of endocrine disrupters. BPA is a chemical used primarily to manufacture polycarbonate plastics and epoxy resins, but is also an additive in other consumer products. Due to extensive use of these products in daily human life, the accumulation of BPA-containing waste in the environment has been a serious concern and a potential threat to public and wildlife health. EE2 is used in oral contraceptives designed for women, and about 16 – 68 percent of each dose is excreted from the body. As a result, EE2 has been found in aquatic environments downstream of wastewater treatment plants.

For more information on endocrine disruptors visit the USGS Columbia Environmental Research Center web page.

New Study Sheds Light on Mammal Declines in Everglades National Park

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Mar 20, 2015.

Summary: Nearly 80 percent of radio-tracked marsh rabbits that died in Everglades National Park in a recent study were eaten by Burmese pythons, according to a new publication by University of Florida and U.S. Geological Survey researchers

Contact Information:

Christian Quintero ( Phone: 813-352-3487 ); Robert McCleery ( Phone: 352-846-0566 );




GAINESVILLE, Fla. – – Nearly 80 percent of radio-tracked marsh rabbits that died in Everglades National Park in a recent study were eaten by Burmese pythons, according to a new publication by University of Florida and U.S. Geological Survey researchers.  

A year later, there was no sign of a rabbit population in the study area.  The study demonstrates that Burmese pythons are now the dominant predator of marsh rabbits, and likely other mid-sized animals in the park, potentially upsetting the balance of a valuable ecosystem.

The study provides the first empirical evidence that the Burmese python caused reductions in marsh rabbit populations in the park, supporting previous studies that suggested pythons were a significant factor in declines of many other mid-sized mammals since becoming established there a few decades ago.

The estimated tens of thousands of Burmese pythons now populating the greater Everglades present a low risk to people in the park, according to previous research by USGS and NPS.

Scientists know that invasive pythons prey on native Everglades mammals, but they didn’t have experimental evidence that pythons could cause population declines or local extinction of mammals, said Robert McCleery, a UF assistant professor in wildlife ecology and conservation who led the study.

While a 2012 study showed that as pythons were proliferating, mammals were declining, it did not directly link the two phenomena. “This study does just that,” said Bob Reed, a USGS research herpetologist and study co-author.

“Mammals play an important role in the Everglades ecosystem, and so recovery of mammal populations is closely tied with recovering the overall health and functionality of this ecosystem,” McCleery said.

In most Florida wetlands, it’s easy to detect marsh rabbit populations by searching for their scat, but the researchers could not find evidence of rabbits in the parts of Everglades National Park they studied during intensive surveys prior to conducting their experiment.

In 2012, a group of scientists that included researchers from Davidson College, USGS and UF compared data on mammal populations from the 1990s – before pythons became widespread in Everglades National Park ─ to results of population surveys conducted between 2003 and 2011. The 2012 study found that significant mammalian population declines coincided in space and time with the proliferation of invasive pythons in the Everglades.  

“Previous studies implicated pythons in mammal declines in the Everglades, but those studies were largely correlative,” said Reed. “This new study moves us from correlation to causation in terms of the impact of invasive pythons on native mammals.” 

To conduct the most recent study, researchers found areas outside of the park that supported large and healthy populations of marsh rabbits. They moved 31 marsh rabbits into select areas in the park in two experimental populations. They also put 15 rabbits in the Loxahatchee National Wildlife Refuge, and captured, collared and released another 49 in Fakahatchee Strand State Park, where they knew there would be few, if any, pythons ─ and used those as control sites. All of the rabbits were equipped with radio-collars so that they could be regularly located.

The researchers radio-tracked the rabbits and found that 77 percent of those that died in the Everglades were eaten by Burmese pythons, and that there was no sign of a rabbit population in the areas where they released them in the park one year later. On the other hand, rabbits remained common at the control site after the experiment. Many animals eat marsh rabbits, but outside the park, they’re most often the victims of bobcats and coyotes.

Furthermore, the warmer and wetter the weather, the more rabbits were consumed by pythons in the park. The researchers suggested this may be because higher water levels allow the pythons to easily swim long distances while searching for food and because they feed more frequently when it’s hot.

Scientists chose to study the pythons’ impacts on marsh rabbit populations because the high reproductive rates of rabbits mean that their populations are typically resilient to predators, McCleery said. The conclusion that pythons are capable of eliminating marsh rabbit populations in Everglades National Park led the authors to suggest that the observed declines in other mid-sized mammal species in the park could also be due to predation by pythons.

The study was published online this week in the journal Proceedings of the Royal Academy B. McCleery’s co-authors include UF graduate student Adia Sovie, as well as Robert Reed, Kristen Hart and Margaret Hunter, all research wildlife biologists with the USGS. 

Frozen Heat Features USGS Science

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Mar 16, 2015.

Summary: The Gas Hydrates Project at the U.S. Geological Survey (USGS) contributed to a four-year international effort by multiple partners, including the United Nations Environmental Programme (UNEP), to formulate a just-released report entitled, “Frozen Heat: A Global Outlook on Methane Gas Hydrates.”

New International Report on Gas Hydrates Draws Heavily from USGS Expertise

Contact Information:

William F.  Waite ( Phone: 508-457-2346 ); Alex Demas ( Phone: 703-648-4421 );




The Gas Hydrates Project at the U.S. Geological Survey (USGS) contributed to a four-year international effort by multiple partners, including the United Nations Environmental Programme (UNEP), to formulate a just-released report entitled, “Frozen Heat: A Global Outlook on Methane Gas Hydrates.”

The two-volume report reviews the state-of-the-art in science and technology related to gas hydrates, providing information in a form accessible to policy makers and stakeholders. The USGS Gas Hydrates Project contributed scientific results, editing, and reviews to assist formulation of the report.    

Gas hydrate is a frozen form of gas and water that occurs naturally at moderate pressure and low temperature. These conditions are characteristic of continuous permafrost and marine sediments at water depths greater than ~350 meters (~1150 ft).  Methane, the primary component of natural gas, is the most common gas incorporated into global gas hydrate deposits. Gas hydrate sequesters about 1600 billion metric tons (~1800 billion US tons) of carbon or up to 25% of the global budget of carbon that can move around the earth-ocean-atmosphere system.

“The USGS plays an active leadership role in gas hydrate research nationally and internationally,” said USGS Energy Resources Program Coordinator Brenda Pierce. “Having USGS experts join with other scientists to present current scientific knowledge to a broad audience in this report serves an important part of our outreach mission.” 

The first volume of the report focuses on the history of gas hydrate research and describes how and where gas hydrates form. USGS research featured prominently in this volume, as USGS scientists have studied the formation and occurrence of gas hydrates all over the world, including Alaska, the Gulf of Mexico, and internationally in countries like Japan, Korea, and India.

Volume I of the report also considers how gas hydrates interact with the environment on a small scale (for example, the link between gas hydrates and deep marine biological communities), and globally (for example, the interplay between gas hydrates and climate).  

“We were pleased to work with U.S. and international partners to contribute scientific expertise to this effort,” said Carolyn Ruppel, Chief of the USGS Gas Hydrates Project. “The report dovetails with our Project’s emphasis on gas hydrates in the natural environment and on the climate and energy resource implications of methane hydrates.”   

Volume 2 discusses gas hydrates as a potential energy resource, including consideration of the technology needed to extract gas from methane hydrates.  USGS scientists have long been active in this research area and participated in tests of methane production from natural gas hydrates in permafrost areas, such as Alaska’s North Slope.

The USGS has a globally recognized research program  studying natural gas hydrates in deepwater and permafrost settings worldwide.  USGS researchers focus on the potential of gas hydrates as an energy resource, the impact of climate change on gas hydrates, and seafloor stability issues.

International Bat Monitoring Research Group Receives

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Mar 09, 2015.

Summary: USGS bat conservation researchers and their partners are being recognized today with the U.S. Forest Service Wings Across the Americas Research Award for their contributions to the North American Bat Monitoring Program (NABat)

Contact Information:

Suzanna Soileau ( Phone: 406-994-7257 ); Catherine Puckett ( Phone: 352-377-2469 );




USGS bat conservation researchers and their partners are being recognized today with the U.S. Forest Service Wings Across the Americas Research Award for their contributions to the North American Bat Monitoring Program (NABat). 

The award will be accepted on behalf of USGS contributions to NABat by Anne Kinsinger, USGS associate director for Ecosystems, at the North American Wildlife Resources Conference in Omaha, Nebr.  USGS partners also being recognized are the U.S. Forest Service, National Park Service, U.S. Fish and Wildlife Service, Department of Defense, Environmental Protection Agency, Wildlife Conservation Society, Bat Conservation International, Bat Conservation Trust, Canadian Wildlife Service, University of California, University of Alberta and Colorado Parks and Wildlife.

“Research on bats is important not only because they are vital to the well-being of ecosystems, but also it is in the best interest of the economy due to the importance of bats for pest control and pollination of native and agricultural plants,” said Kinsinger. “USGS has focused considerable research on issues threatening the health and well being of bat populations in North America. Our participation in NABat provides valuable scientific information for bat conservation.”

Wings Across the Americas is an international program of the U.S. Forest Service that works with a wide range of partners here in the United States and overseas to conserve habitats and populations of birds, bats, butterflies and dragonflies. The award recognizes outstanding conservation work by U.S. Forest Service and partner agencies.

The novelty of the NABat program is a vision for collaborative monitoring of an imperiled species group with a sound statistical underpinning allowing for species distribution modeling across broad geographic regions. Participating USGS researchers provide specific expertise on statistical survey design, statistical analysis of bat acoustic and colony count data and database development informed by experience with many wildlife species such as bats, birds and amphibians.

NABat was developed in conjunction with specialists from other agencies, universities and NGOs in the United States, Canada, the United Kingdom and Mexico in response to growing concerns over threats to bats from continuing and emerging stressors including habitat loss and fragmentation, white-nose syndrome, wind energy development and climate change.  There are currently no national programs to monitor and track bat populations in North America, and NABat seeks to assist in development of such programs that will provide managers and policy makers with the information they need to effectively manage bat populations, detect early warning signs of population declines and estimate extinction risk.

Efforts to date include four workshops and discussions supported by the Landscape Conservation Cooperatives National Council and the National Institute for Mathematical and Biological Synthesis to develop a national monitoring program. These workshops were attended by scientists and researchers from multiple agencies including FWS, USGS, USFS, NPS, University of Calgary and the Canadian Wildlife Service.  In addition, the framework for NABat entitled “A Plan for a North American Bat Monitoring Program (NABat)” will be published in May 2015.

USGS recipients of the Wings Across the Americas award include FORT scientists Laura Ellison, Tom Stanley, Brian Cade, Paul Cryan and Sara Oyler-McCance; NOROCK scientists Kathryn M. Irvine and Steve Corn; UMESC scientist Wayne Thogmartin; Patuxent scientists John Sauer and Matthew Clement; NPWRC scientist Douglas Johnson; NWHC scientist Robin Russell; and CSU Cooperative Research Unit scientist William Kendall.  

 

What Happens to the Water? Assessing Water Quality in Areas with Hydraulically Fractured Oil and Gas Wells

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Mar 03, 2015.

Summary: More data and research are necessary to best understand the potential risks to water quality associated with unconventional oil and gas development in the United States, according to a recent U.S. Geological Survey study.

Contact Information:

Jennifer LaVista ( Phone: 303-202-4764 );




More data and research are necessary to best understand the potential risks to water quality associated with unconventional oil and gas development in the United States, according to a recent U.S. Geological Survey study.

“We mined the national water-quality databases from 1970 - 2010 and were able to assess long-term trends in only 16 percent of the watersheds with unconventional oil and gas resources,” said Zack Bowen, USGS scientist and principal author of the article that appears in American Geophysical Union’s Water Resources Research. “There are not enough data available to be able to assess potential effects of oil and gas development over large geographic areas.”

There is not a national water-quality monitoring program in place that focuses on oil and gas development, so existing national water-quality databases and data on hydraulic fracturing were used to assess water-quality trends in oil and gas areas. The study found no widespread and consistent trends in water quality, such as chloride and specific conductance, in areas where unconventional oil and gas wells are prevalent. The amount of water-quality samples, where they are located and the varying constituents that are measured are limiting factors in existing national databases. 

Hydraulic fracturing is presently the primary stimulation technique for oil and gas production in low-permeability, unconventional resource reservoirs. Comprehensive, published and publicly available information regarding the extent, location and character of hydraulic fracturing and potential effects on regional or national water quality in the United States is scarce. More information can be found on the USGS frequently asked questions on hydraulic fracturing.  

Wildlife Researchers to Give Public Close-Up, Real-Time View of Big Game Fieldwork

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Mar 02, 2015.

Summary: Seeking insights to help moose, elk, mule deer and bighorn sheep populations, researchers from the University of Wyoming, the Wyoming Game and Fish Department, the U.S. Geological Survey and other partners will spend much of March capturing animals on their winter ranges in western and southern Wyoming

Contact Information:

Chad Baldwin, UWYO ( Phone: 307-766-2929 ); Matthew  Kauffman, USGS ( Phone: 307-766-6404 );




LARAMIE, WY — Seeking insights to help moose, elk, mule deer and bighorn sheep populations, researchers from the University of Wyoming, the Wyoming Game and Fish Department, the U.S. Geological Survey and other partners will spend much of March capturing animals on their winter ranges in western and southern Wyoming.

Members of the public will have an opportunity to closely follow the work.

As scientists did during deer captures earlier this winter, researchers with the UW-headquartered Wyoming Migration Initiative (WMI) and personnel from Game and Fish plan to live-tweet the approximately three weeks of research activity and provide Facebook posts about the animal captures multiple times a day.

The tweets will be by WMI Director Matt Kauffman, a UW professor and U.S. Geological Survey scientist. Game and Fish biologists and wardens collaborating on these studies also will tweet from @wgfd. All updates will use the hashtags #wyodeer, #wyomoose, #wyoelk and #wyosheep. Included in the tweets will be maps and data graphics from the forthcoming “Atlas of Wildlife Migration,” a partnership effort with the University of Oregon InfoGraphics Lab cartographers. The USGS, tweeting from @usgs and @USGSCoopUnits, will help promote the discussion to a broader national audience.

WMI’s Facebook page is at www.facebook.com\migrationinitiative. Game and Fish is at www.facebook.com/WyoGFD. The photos, videos, updates and Twitter feed will be posted to a dedicated WMI webpage, www.migrationinitiative.org/capturelivetweetmarch2015.

“Capture and GPS-collar efforts are the primary tools researchers use to study these iconic animals and their movements,” Kauffman says. “Wyomingites care deeply about these herds and the habitats they occupy, so it’s a great opportunity for us to give them, and people beyond Wyoming, a closer view of how and why we are doing this research.”

“Many of these studies have been ongoing for several years in remote and hard-to-access areas of Wyoming. They are used to make important decisions about wildlife management,” says Game and Fish Communications Director Renny MacKay. “Social media allow us to give the public a new look at this valuable research.”

The eight studies that are part of this month’s field work are: 

  • Elk migrations into and out of Yellowstone National Park have been of interest for decades, and new GPS radio collar technology has advanced the mapping of these routes. The Wiggins Fork herd is the last gap in a detailed ecosystem-wide map of Yellowstone’s elk migrations. To fill that gap, researchers will capture and collar elk north of Dubois starting the week of March 2.
  • Nutrition and behavioral response of moose to beetle-killed forest in the Snowy Mountains. The mountain pine beetle epidemic has transformed forested habitats in this range, with uncertain consequences for one of Wyoming's newest moose herds. Moose will be captured and collared March 5-9 between Centennial and Saratoga to assess nutrition and population growth, and to compare current moose movements to those from a pre-beetle kill study conducted in 2004-05.
  • Researchers will capture deer March 10 near Pinedale to evaluate how habitat conditions and human disturbance affect fat levels of deer wintering on and near one of the largest natural gas fields in Wyoming.
  • The nutritional dynamics of the famous Wyoming Range mule deer herd. The March 11 deer capture near Big Piney will continue to look at how many deer this range can support. The next step will be to track fawns to measure survival and cause of mortality.
  • It is unknown how drought affects mule deer as they migrate -- and forage -- from low-elevation winter ranges to mountain summer ranges. This March 12-13 capture between Kemmerer, Cokeville and Evanston will help shed light on whether warming influences summer forage quality, and ultimately the survival and reproduction of migrants.
  • The March 14-15 capture near Rock Springs aims to help advance the understanding of the benefits of migration and guide management and conservation of a spectacular 150-mile deer migration from the Red Desert north of Rock Springs to summer ranges in northwest Wyoming.
  • This March 18 capture of elk between Baggs and Saratoga in the Sierra Madre Mountains is part of an assessment of elk movements before, during and after massive tree fall caused by mountain pine beetles.
  • The interaction of nutrition and disease in bighorn sheep. Pneumonia in bighorn sheep continues to affect their population dynamics, yet it is unknown how ecological conditions affect susceptibility to disease. The March 19-21 capture of bighorns from three herds near Jackson, Dubois and Cody will investigate how nutrition interacts with disease to affect bighorn populations.

Kauffman says the WMI research team -- which also includes UW’s big game nutrition expert, Kevin Monteith; Western EcoSystems Inc. researcher Hall Sawyer; and Yale University biologist Arthur Middleton -- will provide information on the objectives of each study, and what has been learned from ongoing research, through photos, short video interviews, maps and graphics. They’ll also tweet links to existing papers, reports, news articles, interviews, YouTube videos and other information relevant to each study.

Funding for these projects is made possible through extensive collaborations among state and federal managers, sportsmen’s groups, nongovernmental organizations and private foundations. Additional partner details will be shared through Twitter and Facebook as the work progresses.

The public -- and other groups interested in the research -- are encouraged to add comments via Twitter or Facebook throughout the roughly three-week research effort.

 

Science-Based Mitigation Techniques Benefit Greater Sage-Grouse

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Feb 27, 2015.

Summary: Greater sage-grouse nests found in natural gas development areas where mitigation actions were taken to minimize development impacts had slightly higher nest survival than similar areas where such actions were not taken, according to research by U.S. Geological Survey and others

Contact Information:

Carol Schuler ( Phone: 541-750-1031 ); Catherine Puckett ( Phone: 352-377-2469 );




CORVALLIS, Ore. — Greater sage-grouse nests found in natural gas development areas where mitigation actions were taken to minimize development impacts had slightly higher nest survival than similar areas where such actions were not taken, according to research by U.S. Geological Survey and others.

This site-scale study, conducted in a coal-bed methane area of the Powder River Basin in Wyoming, showed that enhanced mitigation efforts somewhat increased the probability of at least one sage-grouse egg hatching per nest in a particular nesting season.  

Mitigation techniques are actions taken to avoid, minimize or offset the impacts of human activities on an ecosystem or a species, such as minimizing sagebrush removal and using remote monitoring of wells to reduce vehicle traffic.

The article, co-authored by the Big Horn Environmental Consultants, Boise State University, and USGS and published in the journal Wildlife Biology, looks at the application of science-based on-site mitigation techniques and sage-grouse nest survival in the Intermountain West.

“High nest survival is critical to the species’ continued existence,” said USGS emeritus scientist and co-author Dr. Mark Fuller. “These are ground-nesting birds that produce on average 6-10 eggs each year. Their nests are vulnerable to predation and other factors, making it difficult for the greater sage-grouse populations to maintain numbers.”

From 2008 to 2011, scientists monitored 296 greater sage-grouse nests in a coal-bed methane development where Anadarko Petroleum Corporation, in cooperation with the Bureau of Land Management, applied mitigation measures above and beyond base mitigation measures to determine if these measures would reduce negative impacts to greater sage-grouse.  The base mitigation measures are required by the BLM in its 2003 Environmental Impact Statement for the Powder River Basin.

Over a 362-square-mile area, researchers measured nest survival in areas where the enhanced mitigation measures were applied, areas where only base techniques were used and in relatively unaltered areas without oil and gas development. Nest survival was determined by the evidence of at least one successfully hatched egg per nest, a standard measurement in avian scientific studies.  Multiple studies have shown that poor nest survival rates can dramatically limit population growth in sage-grouse. Key findings include:

  • Estimated nest survival rates were highest in unaltered areas with no oil or gas development (64 percent), next highest in areas where enhanced mitigation techniques were used (59 percent), and lowest in areas where base mitigation practices were used (54 percent).
  • Of the mitigation measures implemented, piping discharge water to a treatment facility instead of constructing an on-site reservoir for produced waters had the greatest positive benefit on sage-grouse nest survival. Retention reservoirs result in direct habitat loss, may facilitate the spread of sage-grouse predators, and increase habitat for mosquitoes carrying the West Nile virus, thus expanding sage-grouse exposure to this disease.
  • Reducing surface disturbance, particularly sagebrush removal, was also an important factor in nest success. The importance of sagebrush cover to sage-grouse nest survival is well known.

“In asking the question, does on-site mitigation reduce impacts of development on greater sage-grouse, we found that properly targeted mitigation can benefit greater sage-grouse nest survival in energy development areas,” said Chris Kirol, a research biologist with Big Horn Environmental Consultants and lead author of the study. “However, we also found that nests located in areas outside of energy development had the highest survival rates. Our results can help inform future adaptive management and greater sage-grouse conservation efforts in sagebrush habitat affected by energy development.”

Sagebrush habitat is increasingly being developed for oil and gas resources, and land managers face complex challenges in balancing energy demands with conservation measures for sagebrush-dependent species such as the greater sage-grouse. Agencies responsible for managing sagebrush habitat and greater sage-grouse populations encourage the use of adaptive management measures, such as science-based mitigation during oil and gas development and operations. Adaptive management is an approach for improving resource management by learning from and incorporating previous management outcomes into present plans.

Greater sage-grouse occur in parts of 11 U.S. states and 2 Canadian provinces in western North America.  The U.S. Fish and Wildlife Service is formally reviewing the status of greater sage-grouse to determine if the species is warranted for listing under the Endangered Species Act.

Coping with Earthquakes Induced by Fluid Injection

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Feb 19, 2015.

Summary: A paper published today in Science provides a case for increasing transparency and data collection to enable strategies for mitigating the effects of human-induced earthquakes caused by wastewater injection associated with oil and gas production in the United States

Contact Information:

Susan  Garcia ( Phone: 650-346-0998 ); Leslie  Gordon ( Phone: 650-329-4006 );




MENLO PARK, Calif.— A paper published today in Science provides a case for increasing transparency and data collection to enable strategies for mitigating the effects of human-induced earthquakes caused by wastewater injection associated with oil and gas production in the United States.  The paper is the result of a series of workshops led by scientists at the U.S. Geological Survey in collaboration with the University of Colorado, Oklahoma Geological Survey and Lawrence Berkeley National Laboratory, suggests that it is possible to reduce the hazard of induced seismicity through management of injection activities.

Large areas of the United States that used to experience few or no earthquakes have, in recent years, experienced a remarkable increase in earthquake activity that has caused considerable public concern as well as damage to structures. This rise in seismic activity, especially in the central United States, is not the result of natural processes.

Instead, the increased seismicity is due to fluid injection associated with new technologies that enable the extraction of oil and gas from previously unproductive reservoirs. These modern extraction techniques result in large quantities of wastewater produced along with the oil and gas. The disposal of this wastewater by deep injection occasionally results in earthquakes that are large enough to be felt, and sometimes damaging. Deep injection of wastewater is the primary cause of the dramatic rise in detected earthquakes and the corresponding increase in seismic hazard in the central U.S.  

“The science of induced earthquakes is ready for application, and a main goal of our study was to motivate more cooperation among the stakeholders — including the energy resources industry, government agencies, the earth science community, and the public at large — for the common purpose of reducing the consequences of earthquakes induced by fluid injection,” said coauthor Dr. William Ellsworth, a USGS geophysicist. 

The USGS is currently collaborating with interested stakeholders to develop a hazard model for induced earthquakes in the U.S. that can be updated frequently in response to changing trends in energy production.

“In addition to determining the hazard from induced earthquakes, there are other questions that need to be answered in the course of coping with fluid-induced seismicity,” said lead author of the study, USGS geophysicist Dr. Art McGarr. “In contrast to natural earthquake hazard, over which humans have no control, the hazard from induced seismicity can be reduced. Improved seismic networks and public access to fluid injection data will allow us to detect induced earthquake problems at an early stage, when seismic events are typically very small, so as to avoid larger and potentially more damaging earthquakes later on.”

“It is important that all information of this sort be publicly accessible, because only in this way can it be used to provide the timely guidance needed to reduce the hazard and consequences of induced earthquakes,” said USGS hydrologist and co-author of the paper, Dr. Barbara Bekins.  

A Decade of Change in America's Arctic: New Land Cover Data Released for Alaska

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Feb 18, 2015.

Summary: The latest edition of the National Land Cover Dataset (NLCD 2011) for Alaska is now publicly available

Contact Information:

Jon Campbell ( Phone: 703-648-4180 ); Collin  Homer ( Phone: 605-594-2714 );




The latest edition of the National Land Cover Dataset (NLCD 2011) for Alaska is now publicly available.

The extensive NLCD database continues to add to our understanding of where land cover change has occurred across the Nation over time.  Derived from carefully calibrated, long-term observations of Landsat satellites, NLCD data are used for thousands of applications such as best practices in land management, indications of climate change, determining ecosystem status and health, and assessing spatial patterns of biodiversity.

“Recognizing that ​land cover is ​changing ​rapidl​y​ in the high latitudes of the Arctic, it is vital that we have the clearest view of ​the spatial and temporal patterns associated with those changes,” said Suzette Kimball, acting Director of the U.S. Geological Survey.  “As the Arctic becomes more accessible to human endeavors, understanding changes in land cover becomes critical in both using and preserving Alaska’s precious resources.” 

For Alaska, this database is designed to provide ten-year cyclical updating of the state's land cover and associated changes. Based on Landsat satellite imagery taken in 2011, the data describe the land cover of each 30-meter cell of land in Alaska and identifies which ones have changed since the year 2001. Nearly six such cells - each 98 feet long and wide - would fit on a football field. 

The updated information tells an objective 10-year land cover change story for Alaska. With a decade of change information available, resource managers, researchers, planners in government and industry —anyone who wishes to investigate the topic — can better understand the trajectory of land cover change patterns and gain insight about land cover change processes.

By far the greatest Alaska change across this decade has been the conversion of forests to shrub and grasslands, primarily as a result of wild land fire. Other land cover categories that have experienced losses from 2001-2011 include perennial ice and snow and wetlands.

NLCD is constructed by the 10-member federal interagency Multi‑Resolution Land Characteristics Consortium (MRLC). This on-going 20 year collaboration of MRLC demonstrates an exemplary model of cooperation among government entities that combine resources to efficiently provide digital land cover for the Nation.  Their teamwork in producing the NLCD not only significantly advances land cover science and data, but saves taxpayer money.

Land cover is broadly defined as the biophysical pattern of natural vegetation, agriculture, and urban areas. It is shaped by both natural processes and human influences. NLCD 2011 products provide 20 classes of land cover in Alaska and also define the degree of surface imperviousness in urban areas (usually composed of concrete, asphalt, stone, and metal — widely recognized as a key indicator of environmental quality in urban areas).

The range and spatial accuracy of this information have made it essential to thousands of users,  enabling managers of public and private lands, urban planners, agricultural experts, and scientists with many different interests (for instance, climate, invasive species or hydrogeography) to identify critical characteristics of the land and patterns of land cover change. The data informs many fields of environmental investigation, from monitoring forests to modeling water runoff in urban areas.

NLCD 2011 products were released for the conterminous U.S. last year; products for Hawaii and Puerto Rico will be released later this year. NLCD data can be downloaded free of charge at the MRLC website

Learn more

Multi-Resolution Land Characteristics Consortium (MRLC)

USGS Land Change Science

USGS Land Cover Institute

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These three panels from the National Land Cover Database depict land cover change in the vicinity of Fairbanks, AK, from 2001 to 2011. The left panel shows the status of the land cover in 2001 (forests in green, shrublands in brown, wetlands in blue and urban in red) The middle panel shows the updated land cover in 2011 and the right panel shows areas where change occurred over this 10 years. This change was caused by a wildfire which converted large areas of forests to shrub and grasslands (shades of light brown in the right panel). Approximately one million acres burn across Alaska each year. (High resolution image)

Conowingo Dam Above 90 Percent Capacity For Sediment Storage

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Feb 18, 2015.

Summary: The Conowingo Dam on the Susquehanna River is at about 92 percent capacity for sediment storage according to new U.S. Geological Survey research

Contact Information:

Michael Langland ( Phone: 717-730-6953 ); Hannah Hamilton ( Phone: 703-648-4356 );




The full report is available online

The Conowingo Dam on the Susquehanna River is at about 92 percent capacity for sediment storage according to new U.S. Geological Survey research.

Since the dam’s construction in 1929, sediment and nutrients have been building up behind it, being released periodically downriver and into the Chesapeake Bay, especially during high flow events.

“Storage capacity in Conowingo Reservoir continues to decrease, and ultimately that means more nutrients and sediment will flow into the Bay,” says Mike Langland, a USGS scientist and author of the study. “Understanding the sediments and nutrients flowing into the Bay from the Susquehanna River is critical to monitoring and managing the health of the Bay.”

Previous research has shown that having excess nutrients in the Bay depletes the water of oxygen needed to maintain healthy populations of fish, crabs, and oysters.  Additionally, the nutrients, along with sediment, cloud the water, disturbing the habitat of underwater plants crucial for aquatic life and waterfowl.

At full sediment-storage capacity, the Conowingo Reservoir will be about one-half filled with sediment, with the remainder--about 49 billion gallons--flowing water.  That amount of sediment could fill approximately 265,000 rail cars, which if lined up would stretch more than 4,000 miles.

The Susquehanna River is the largest tributary to Chesapeake Bay and transports about half of the total freshwater input to the Bay, along with substantial amounts of sediment, nitrogen and phosphorus.

Measuring the capacity of the dam to hold sediments and nutrients contributes to an improved understanding of factors that influence the health of the Chesapeake Bay.

Three hydroelectric dams and their associated reservoirs on the lower Susquehanna River have been impacting sediment and nutrient transport since construction in the early 1900’s. Previous USGS studies have shown the two upstream reservoirs have reached their sediment storage capacity and the most downstream dam and reservoir, the Conowingo, was also losing its ability to trap nutrients and sediment from reaching the Chesapeake Bay. A 2012 USGS report revealed that, even though the Conowingo reservoir had not yet reached its maximum storage capacity, it had begun to lose its phosphorus and sediment-trapping ability, with increasing amounts going into the Bay.

Due to the concerns about increasing nutrient and sediments loads flowing into the Bay, the U.S. Army Corps of Engineers, working with several partners, will soon be releasing ,the Lower Susquehanna River Watershed Assessment. The study suggests several sediment-management options for the reservoirs on the Lower Susquehanna River and indicated additional monitoring and research are needed to support management decisions.

The long-term analysis (1900-2012) conducted for this new USGS study reported here revealed how past practices affected sediment transport in the Susquehanna River Basin.

The USGS study, in addition to providing the current estimate of sediment capacity also provides a longer-term (100 years) analysis of sediment flowing into the reservoirs.

Sediment loads transported over the past 100 years in the Susquehanna River into the reservoirs have decreased from 8.7 million tons per year in the early part of the 20th century to the current level of about 3.5 million tons. The declines of sediment into the reservoirs since the 1950s are most likely related to introduction of soil conservation practices, land reverting back to forest, and better management of stockpiled coal piles.

Since construction of Conowingo Dam was completed in 1929, an average 70 percent of the transported sediment reaching the upper Chesapeake Bay is from the Susquehanna watershed. The additional 30 percent of the sediment is being scoured, or removed from sediment deposited in the reservoirs.

From 1929 through 2012, approximately 470 million tons of sediment was transported down the Susquehanna River into the reservoir system.  Of that number, approximately 290 million tons were trapped behind dams in the reservoirs, and approximately 180 million tons were transported to Chesapeake Bay. The reservoirs are continuously losing their ability to trap sediment and more is flowing into the Bay.

Information from this report and new partner studies will be used by the U.S. Environmental Protection Agency Chesapeake Bay Program and the state partners in considering options to reduce nutrient and sediment loads to help meet the requirements of the Chesapeake Bay Total Maximum Daily Load.

The study, Sediment Transport and Capacity Change in Three Reservoirs, Lower Susquehanna River Basin, Pennsylvania and Maryland, 1900–2012 Open-File Report 2014-1235 is available online.

Additional information on USGS Susquehanna results and Chesapeake Studies can be found online.

Show Me New Data for Show-Me State Maps

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Feb 18, 2015.

Summary: Newly released US Topo maps for Missouri now feature selected trails and other substantial updates. The data for the trails is provided to the USGS through a nation-wide “crowdsourcing” project managed by the International Mountain Biking Association (IMBA)

Contact Information:

Mark Newell, APR ( Phone: 573-308-3850 ); Larry Moore ( Phone: 303-202-4019 );




Newly released US Topo maps for Missouri now feature selected trails and other substantial updates. The data for the trails is provided to the USGS through a nation-wide “crowdsourcing” project managed by the International Mountain Biking Association (IMBA). Several of the 1,196 new US Topo quadrangles for the state now display public trails along with additional improved data layers such as public land survey information, map symbol redesign and new road source data.

"The US Topo maps are widely used and appreciated by many state and local agencies," said Shelley Silch, The National Map liaison for Missouri and Illinois. "The addition of numerous trials to the new state US Topo quadrangles is a great advancement, as Missouri has been named the 'best trails state" by American Trails." 

For Missouri residents and visitors who want to explore the rolling Ozark landscape on a bicycle seat or by hiking, the new trail features on the US Topo maps will come in handy. During the past two years the IMBA, in a partnership with the MTB Project, has been building a detailed national database of mountain bike 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.  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.

Another important addition to the new Missouri US Topo maps is the inclusion of Public Land Survey System data. PLSS is a way of subdividing and describing land in the US. All lands in the public domain are subject to subdivision by this rectangular system of surveys, which is regulated by the U.S. Department of the Interior.

These new maps replace the first edition US Topo maps for Missouri 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/

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Updated 2015 version of the Weldon Spring, Missouri quadrangle with orthoimage turned on. (1:24,000 scale) (high resolution image 2.5 MB) Vintage 1903 quadrangle covering the O’Fallon, Missouri area from the USGS Historic Topographic Map Collection. 1:25,000 scale (high resolution image 3.3 MB) Updated 2015 version of Weldon Spring quadrangle with orthoimage turned off to better see the trail network. (1:24,000 scale) (high resolution image 1.8 MB)

Largest Dam Removal in U.S. History Scientifically Characterized

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Feb 17, 2015.

Summary: The effects of dam removal are better known as a result of several new studies released this week by government, tribal and university researchers. The scientists worked together to characterize the effects of the largest dam removal project in U.S. history occurring on the Elwha River of Washington State

Contact Information:

Jonathan Warrick ( Phone: 831-460-7569 ); Paul Laustsen ( Phone: 650-329-4046 );




Aerial photos of the Elwha River mouth before and during dam removal. Photos show (A) the river mouth wetlands before dam removal, (B) the turbid coastal plume that occurred during much of the dam removal project, and (C) the expansion of the river mouth delta by sediment deposition. Photos provided by Ian Miller of Washington Sea Grant, Jonathan Felis of USGS, and Neal and Linda Chism of LightHawk.
Aerial photos of the Elwha River mouth before and during dam removal. Photos show (A) the river mouth wetlands before dam removal, (B) the turbid coastal plume that occurred during much of the dam removal project, and (C) the expansion of the river mouth delta by sediment deposition. Photos provided by Ian Miller of Washington Sea Grant, Jonathan Felis of USGS, and Neal and Linda Chism of LightHawk. (High resolution image)

SEATTLE — The effects of dam removal are better known as a result of several new studies released this week by government, tribal and university researchers. The scientists worked together to characterize the effects of the largest dam removal project in U.S. history occurring on the Elwha River of Washington State. New findings suggest that dam removal can change landscape features of river and coasts, which have ecological implications downstream of former dam sites.

“These studies not only give us a better understanding of the effects of dam removal, but show the importance of collaborative science across disciplines and institutions,” said Suzette Kimball, acting director of the U.S. Geological Survey.

Five peer-reviewed papers, with authors from the U.S. Geological Survey, Reclamation, National Park Service, Washington Sea Grant, NOAA Fisheries, the Lower Elwha Klallam Tribe, and the University of Washington, provide detailed observations and insights about the changes in the river’s landforms, waters and coastal zone during the first two years of dam removal. During this time, massive amounts of sediment were eroded from the drained reservoirs and transported downstream through the river and to the coast. 

One finding that intrigued scientists was how efficiently the river eroded and moved sediment from the former reservoirs; over a third of the 27 million cubic yards of reservoir sediment, equivalent to about 3000 Olympic swimming pools filled with sediment, was eroded into the river during the first two years even though the river’s water discharge and peak flows were moderate compared to historical gaging records. 

This sediment release altered the river’s clarity and reshaped the river channel while adding new habitats in the river and at the coast. In fact, the vast majority of the new sediment was discharged into the coastal waters of the Strait of Juan de Fuca, where the river mouth delta expanded seaward by hundreds of feet. 

“The expansion of the river mouth delta is very exciting, because we are seeing the rebuilding of an estuary and coast that were rapidly eroding prior to dam removal,” said USGS research scientist and lead author of the synthesis paper, Dr. Jonathan Warrick. 

Although the primary goal of the dam removal project is to reintroduce spawning salmon runs to the pristine upper reaches of the Elwha River within Olympic National Park, the new studies suggest that dam removal can also have ecological implications downstream of the former dam sites. These implications include a renewal of the sand, gravel and wood supplies to the river and to the coast, restoring critical processes for maintaining salmon habitat to river, estuarine and coastal ecosystems.

“These changes to sediment and wood supplies are important to understand because they affect the river channel form, and the channel form provides important habitat to numerous species of the region,” stated USGS research scientist and river study lead author, Dr. Amy East.

The final stages of dam removal occurred during the summer of 2014. Some sediment erosion from the former reservoirs will likely continue. The Elwha Project and research teams are continuing to monitor how quickly the river returns to its long-term restored condition.

“We look forward to seeing when the sediment supplies approach background levels,” said Reclamation engineer and co-author, Jennifer Bountry, “because this will help us understand the length of time that dam removal effects will occur.” 

The five new papers can be found in Elsevier’s peer-reviewed journal, Geomorphology, and they focus on the following topics of the large-scale dam removal on the Elwha River, Washington (web-based publication links using digital object identifiers, doi, are provided in parentheses): 

New Maps for Nevada Include Trails

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Feb 11, 2015.

Summary: Newly released US Topo maps for Nevada now feature selected trails. The data for the trails is provided to the USGS through a nation-wide “crowdsourcing” project managed by the International Mountain Biking Association (IMBA)

Contact Information:

Mark Newell, APR ( Phone: 573-308-3850 ); Larry Moore ( Phone: 303-202-4019 );




Newly released US Topo maps for Nevada now feature selected trails. The data for the trails is provided to the USGS through a nation-wide “crowdsourcing” project managed by the International Mountain Biking Association (IMBA). Several of the 1,785 new US Topo quadrangles for the state now display public trails along with other improved data layers such as land survey information (PLSS), map symbol redesign and new road source data.

"Users of the US Topo maps in our state are excited about the release of these new versions," said Carol Ostergren, The National Map Liaison for Nevada. "Nevada features numerous trails, so the addition of several mountain bike trails will increase the use of the new US Topo maps. Also, adding PLSS will assist many of our users who have been asking for that data for a long time."

For Nevada residents and visitors who want to explore the stunning desert landscape on a bicycle seat or hiking shoes, the new trail features on the US Topo maps will come in handy. During the past two years the IMBA, in a partnership with the MTB Project, has been building a detailed national database of mountain bike 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 and ensure accuracy and confirm that the trail is legal.  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.

Another important addition to the new Nevada US Topo maps is the inclusion of Public Land Survey System data. PLSS is a way of subdividing and describing land in the United States. All lands in the public domain are subject to subdivision by this rectangular system of surveys, which is regulated by the U.S. Department of the Interior.

These new maps replace the first edition US Topo maps for Nevada 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/

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Updated 2015 version of Boulder City, Nevada quadrangle with orthoimage turned on. (1:24,000 scale. (high resolution image 1.1 MB) Vintage 1886 quadrangle covering the Boulder City, Nevada and Camp Majove, Arizona area from the USGS Historic Topographic Map Collection. 1:25,000 scale. (high resolution image 1.6 MB) Updated 2015 version of Boulder City, Nevada quadrangle with orthoimage turned off to better see the trail network. (1:24,000 scale) (high resolution image 610 KB)

Predicting Plant Responses to Drought

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Feb 10, 2015.

Summary: A new U.S. Geological Survey study shows how plants’ vulnerability to drought varies across the landscape; factors such as plant structure and soil type where the plant is growing can either make them more vulnerable or protect them from declines

Long-term Research to Help Protect Drylands

Contact Information:

Seth Munson ( Phone: 928-523-7740 ); Marisa Lubeck ( Phone: 303-526-6694 );




A new U.S. Geological Survey study shows how plants’ vulnerability to drought varies across the landscape; factors such as plant structure and soil type where the plant is growing can either make them more vulnerable or protect them from declines.

Recent elevated temperatures and prolonged droughts in many already water-limited regions throughout the world, including the southwestern U.S., are likely to intensify according to future climate model projections. This warming and drying can negatively affect vegetation and could lead to the degradation of wildlife habitat and ecosystems. It is critical for resource managers and other decision-makers to understand where on the landscape vegetation will be affected so they can prioritize restoration and conservation efforts, and plan for the future.

To better understand the potential detrimental effects of climate change, USGS scientists developed a model to evaluate how plant species will respond to increases in temperature and drought. The model integrates knowledge about how plant responses are modified by landscape, soil and plant attributes that are integral to water availability and use. The model was tested using fifty years of repeat measurements of long-living, or perennial, plant species cover in large permanent plots across the Mojave Desert, one of the most water-limited ecosystems in North America. The report, published in the Journal of Ecology, is available online

“The impacts of drought are not going away, and sound science to understand how water-limited ecosystems will respond is important for managers to plan climate adaptation strategies,” said Seth Munson, USGS scientist and lead author of the study. “By using monitoring results that scientists and managers have diligently reported for the last several decades, our study helps forecast the future state of drylands.” 

Results show that plants respond to climate differently based on the physical attributes of where they are growing in the Mojave Desert. For example, deep-rooted plants were not as vulnerable to drought on soils that allowed for deep-water flow. Also, shallow-rooted plants were better buffered from drought on soils that promoted water retention near the surface. This information may be helpful for resource managers to minimize disturbance in areas that are likely vulnerable to water shortages. 

Water moves horizontally and vertically through the landscape, which affects the amount of water plants can take up through their roots. There is more to plant water availability and use than the precipitation that falls out of the sky. Understanding how water moves through ecosystems is critical in regions that already have marginal water available for plant growth. Predicting climate change impacts in these areas requires more than an understanding of climate alone.

This study was done in cooperation with the University of Arizona, the Fort Irwin Directorate of Public Works, Utah State University, University of Nevada, California Polytechnic State University, Ohio State University, California State University and the National Park Service. 

Virginia Earthquake Aftershocks Identify Previously Unknown Fault Zone

By OC_Web@usgs.gov (Office of Communications and Publishing) from USGS Newsroom. Published on Feb 10, 2015.

Summary: Aftershocks from the 2011 Virginia earthquake have helped scientists identify the previously unknown fault zone on which the earthquake occurred

New Quake Research Brings This, Other Discoveries to Public

Contact Information:

Wright Horton ( Phone: 703-648-6933 ); Christian Quintero ( Phone: 813-498-5019 );




RESTON, Va.-- Aftershocks from the 2011 Virginia earthquake have helped scientists identify the previously unknown fault zone on which the earthquake occurred. The research marked one of the few times in the Eastern United States that a fault zone on which a magnitude-5-or-more earthquake occurred was clearly delineated by aftershocks, and is just one finding in a 23-chapter book with new information on the Virginia earthquake and eastern seismic hazards.

Research by the U.S. Geological Survey along with its partners and collaborators defined the newly recognized fault zone, which has been named the “Quail” fault zone. USGS and others worked cooperatively in an effort to capture the accurate locations of hundreds of aftershocks by deploying portable seismic instruments after the earthquake. Most of these aftershocks were in the Quail fault zone, and outlying clusters of shallow aftershocks helped researchers to identify and locate other active faults. Knowing where to look for the active faults helped to focus geologic mapping, geophysical imaging and other technologies to better understand earthquakes in the Central Virginia Seismic Zone and Eastern U.S.

The book includes contributions by Virginia Tech, the Virginia Department of Mines, Minerals, and Energy and the U.S. Nuclear Regulatory Commission among many others.

“Studies of the Virginia earthquake have improved our understanding of earthquakes and seismic hazards in Eastern North America,” said USGS geologist Wright Horton. “The Virginia earthquake served as a ‘wakeup call’ for many residents of the Eastern U.S., where the probability of major earthquakes is fairly low, but many buildings are vulnerable to damage during earthquakes.”  

The new book, “The 2011 Mineral, Virginia, Earthquake, and Its Significance for Seismic Hazards in Eastern North America”, is a collection of articles that covers a broad range of subjects relating to the 2011 earthquake. Highlights from the book include:

  • Earthquake shaking and its effects, such as widespread changes in groundwater levels, occurred at greater distances from the source in this and other Eastern U.S. earthquakes as opposed to those of comparable magnitude on the West Coast
  • Shaking intensities and related damage were more severe along the northeast trend of the Appalachians than in northwestward directions across this trend
  • Evidence that the earthquake ground motion was amplified in parts of D.C. and other areas around the Chesapeake Bay with thicker coastal plain sediments or artificial fill is stimulating further studies to determine how much seismic shaking is amplified by local geological conditions
  • Analysis of data on residential property damage in the epicentral area delineates a “bulls eye” distribution of shaking intensities and also confirms that damage is influenced by the age and construction of homes
  • Damage to unreinforced masonry buildings in D.C., as far as 80 miles from the epicenter, highlights the seismic risk to buildings in Eastern North American cities. Ground motions occur at farther distances from the epicenter on the East Coast than other parts of the U.S., and buildings are not as well designed to sustain these motions as in other locations 
  • Seismic reflection imaging—which is similar to medical sonograms—and geophysical flight surveys of the Earth’s magnetic and gravity fields were used to image geologic structures down to about 5 miles underground where the earthquake occurred
  • Airborne laser swath mapping using lidar, and radiometric flight surveys—which mapped radioactive elements in rocks and soils within a few feet of the land surface—identified and accurately located preexisting linear features including faults associated with aftershock clusters for detailed surface geologic mapping and trenching studies
  • New geologic mapping and trenching reveal previously unknown faults and evidence that the faults were active more than once in the past
  • Recorded ground motions from the Virginia earthquake were consistent with previous USGS estimates for the region, and they are helping to improve the assessments of potential earthquake ground motions used to design buildings that will be better able to withstand strong earthquakes

Earthquakes in Eastern North America are not as frequent or as well understood as those along Earth's tectonic plate boundaries, such as on the West Coast. The magnitude 5.8 Virginia earthquake was the largest to occur in the eastern U.S. since the 1886 earthquake near Charleston, South Carolina, and it may have been felt by more people than any other earthquake in U.S. history. It was felt over much of the Eastern U.S. and Southeastern Canada, triggered the automatic safe shutdown of a nuclear power plant and caused significant damage from Central Virginia to the National Capital Region. The earthquake provided a wealth of modern scientific and engineering data to better understand earthquakes and seismic hazards in Eastern North America.

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