Near real-time river water-quality forecasts for the Cuyahoga Valley National Park (CVNP) in northeastern Ohio are now available online.
U.S. Geological Survey scientists, in collaboration with the National Park Service, have developed a system to quickly forecast bacteria levels and estimate water-quality conditions at a site along the Cuyahoga River within the CVNP. A computer model uses current weather and environmental conditions to forecast Escherichia coli (E. coli) bacteria concentrations in the river, and results are automatically posted on the Ohio Nowcast website. This information can help recreationalists plan river trips and better inform park managers.
“Our method and model to predict water-quality could be customized for other river locations across the nation as long as unique environmental factors are considered and tested for at each location,” said Amie Brady, USGS research hydrologist.
While the predictions are available daily for the site along the river, visitors should still use caution when contacting Cuyahoga River water—especially after heavy rainfall—because storm water discharge and combined-sewer overflows from urban areas upstream of the park can result in elevated bacteria levels.
"The park has always been concerned about the water-quality of the river and the safety of our visitors," said Stan Austin, Superintendent of CVNP. "The predictive model will provide us with critical information as we move towards exploring greater recreational use of the river."
Managers issue water-quality advisories or closings in the United States when concentrations of indicator organisms, such as E. coli, exceed state-designated safety standards. Indicator organisms are present in sewage and waste, and signify the possible presence of pathogens, or disease-causing organisms.
Current methods to determine levels, or concentrations, of E. coli take at least 18 hours to complete. During this period, E. coli concentrations can change dramatically. This means that a site may be closed unnecessarily, or an advisory may not be posted on a day when the risk of pathogen exposure is high.
"Instead of waiting for E. coli to grow in the laboratory, we can quickly measure factors that explain changes in E. coli concentrations, enter them into a computer program, and obtain a prediction of recreational water-quality in near real-time," Brady said.
For the Cuyahoga River site, USGS scientists found that the best factors to estimate E. coli levels were turbidity, or cloudiness, of the water, and rainfall totals from the National Weather Service within the last 48 hours.
"With information from a water-quality monitor that was installed in 2012, we can make daily water-quality forecasts that are fully automated," said Brady. "We will maintain manual sample collection to ensure that the model continues to work well, but we will no longer have to sample every day."
The CVNP encompasses 33,000 acres along the Cuyahoga River between Cleveland and Akron, Ohio, and is managed by the National Park Service, CVNP.
For more information, please visit the USGS Ohio Water Science Center website.
SEATTLE — The spread of a highly virulent fish virus in four separate coastal Washington watersheds from 2007-2011 has been described in a new research paper by the U.S. Geological Survey. The most probable source of the virus was identified as steelhead trout originating from the Columbia River Basin.
The research, conducted with state, federal, tribal, and University of Washington partners, used genetic testing of the virus to characterize the emergence of Infectious Hematopoietic Necrosis Virus, better known as IHNV, in coastal Washington steelhead trout between 2007-2011. During that time, new steelhead-specific strains of the virus spread to seven different salmonid culture facilities in four different coastal watersheds, and caused significant mortality in juvenile steelhead trout, seriously impacting conservation programs.
In this work scientists identified the strain types for over 200 coastal virus samples and compared them with IHNV types detected previously throughout the Pacific Northwest. This revealed that there were at least two separate introductions of the steelhead-specific virus into coastal fish populations and that the most probable source of these introductions was the Columbia River Basin. These new data will help resource managers in efforts to prevent further spread of IHNV, and potentially other important fish pathogens, throughout the Pacific Northwest.
"Knowing how to detect this virus and how it moves between costal populations is extremely important in designing and implementing preventative measures to protect steelhead populations" said Ray Brunson, recently retired fish health specialist from the U.S. Fish and Wildlife Service who oversaw his agency's role from 2007-2011.
Questions remain about how the virus reached coastal fish and why the virus has not been detected in coastal watersheds since late 2011. "This work shows that transmission of IHNV cannot be wholly understood from monitoring individual rivers, so studies such as this one that look at how the virus moves throughout the interconnected Pacific Northwest are essential to support fish health programs." said Rachel Breyta, lead author from the University of Washington, working at the USGS’ Western Fisheries Research Center.
The new research will appear in an upcoming volume of the journal 'Diseases of Aquatic Organisms'. Additional information on IHNV genetic typing at the Western Fisheries Research Center is available online.
"Emergence of MD type Infectious Hematopoietic Necrosis Virus in Washington Coastal Steelhead Trout" published in the journal Diseases of Aquatic Organisms, was co-authored by scientists from the USGS Western Fisheries Research Center, in collaboration with the University of Washington, Northwest Indian Fisheries Commission, Washington Department of Fish and Wildlife and the U.S. Fish and Wildlife Service.
Standard atomic weights for chemical elements have commonly been considered as constants of nature, along with the speed of light and the attraction of gravity. Hold on to your Newtonian hat and prepare for the possibility of elementary nuances.
The International Union of Pure and Applied Chemistry (IUPAC) Commission on Isotopic Abundances and Atomic Weights has published a new table that expresses the standard atomic weights of magnesium and bromine as intervals, rather than as single standard values. In addition, improved standard atomic weights have been determined for germanium, indium, and mercury. This new table is the result of cooperative research supported by the U.S. Geological Survey, IUPAC, and other contributing Commission members and institutions.
Modern analytical techniques can measure the atomic weight of many elements with such precision that small variations in an element’s atomic weight serve as markers for certain physical, chemical, and biological processes.
"The USGS has a long history of research in this field," said acting USGS Director Suzette Kimball. "Through isotopic analysis, USGS scientists detect slight variations in atomic weights of various elements, which can be applied to a wide variety of mission-critical investigations, such as the identification of the geographic origin of materials, quantification of surface-water groundwater interaction, and understanding paleoclimatic conditions."
"We are pleased to partner with the International Union [IUPAC] in this vital work," Kimball added.
Atoms of the same element that have different masses are called "isotopes." The atomic weight of an element depends upon how many stable isotopes it has and the relative amounts of each stable isotope present in a sample containing the element.
Elements with only one stable isotope do not exhibit variations in their atomic weights. For example, the standard atomic weights for fluorine, aluminum, sodium, and gold are constant. Their values are known to better than six decimal places. Variations in atomic weight occur when an element has two or more naturally occurring stable isotopes that vary in abundance, depending on the sample.
The standard atomic weights of magnesium and bromine will now be expressed as intervals to more accurately convey this variation in atomic weight. For example, bromine commonly is considered to have a standard atomic weight of 79.904. However, its actual atomic weight can be anywhere between 79.901 and 79.907, depending on where the element is found.
IUPAC previously adjusted the standard atomic weights of the elements hydrogen, lithium, boron, carbon, nitrogen, oxygen, silicon, sulfur, chlorine and thallium as intervals to reflect variations in their atomic weights.
"For more than a century and a half, many students have been taught to use standard atomic weights — a single value — found on the inside cover of chemistry textbooks and on the periodic table of the elements," said Ty Coplen, director of the USGS Stable Isotope Laboratory in Reston, Va. "Though this change offers significant benefits in the understanding of chemistry, one can imagine the challenge now to educators and students who will have to select a single value out of an interval when doing chemistry calculations."
Practical applications of this research can be easily found in daily life. For example, precise measurements of the abundances of isotopes of carbon can be used to determine the purity and source of food products, such as vanilla and honey. Isotopic measurements of nitrogen, chlorine and other elements are used for tracing pollutants in streams and groundwater. In investigations of sports doping, performance enhancing testosterone can be identified in the human body because the atomic weight of carbon in natural human testosterone is different from that in pharmaceutical testosterone.
The importance of determining precise atomic weights has long been recognized. As far back as 1882, Frank W. Clarke, then a professor at the University of Cincinnati, prepared a table of atomic weights for use in science, industry, and trade. He carried on this work as Chief Chemist of the USGS (1883-1924). Clarke was a founder of the American Chemical Society and a member of the National Academy of Sciences. Recently, IUPAC has overseen the periodic evaluation and dissemination of atomic-weight values.
The report, published in Pure and Applied Chemistry, also includes educational material and a Periodic Table of the Isotopes illustrating the relationship between isotopes and atomic weights.
ATLANTA— Georgia's groundwater levels showed a general decline between 2010 and 2011 in response to low rainfall and increased pumping, according to a recent USGS publication.
The greatest declines in the aquifers were in the southwestern part of the state where groundwater levels dropped as much as 18 feet in the Upper Floridan aquifer, 22 feet in the Claiborne aquifer, 30 feet in the Clayton aquifer, and 17 feet in the Cretaceous aquifer system.
The U.S. Geological Survey, in cooperation with numerous local, State, and Federal agencies, operates a monitoring network to help water officials address problems related to water supply, water use, and water quality. Data from the monitoring network in Georgia indicate that groundwater levels declined in 158 of the 168 wells monitored during 2010-2011.
"Data from the USGS network are essential for water-resources assessment and management," explained John Clarke, USGS Hydrologist. "Water-level measurements from observation wells are the principal source of information about the hydrologic stresses on aquifers and how these stresses affect groundwater recharge, storage, and discharge. This information can be used to develop management plans for groundwater withdrawal in areas where problems have or may develop."
The report, written for Georgia's water resource managers, should be useful for anyone interested in the state's water quality and availability. It includes hydrographs showing monthly mean groundwater levels and trends together with maps showing groundwater-level trends during 2010–2011. In addition to continuous water-level data, the report includes maps showing groundwater levels and flow directions for the Upper Floridan aquifer in Camden, Charlton, and Ware Counties; the Brunswick-Glynn County area; and the Albany–Dougherty County area. Similar maps were also constructed for the Cretaceous aquifer system in the Augusta–Richmond County area. In general, water levels in these areas were lower during 2011 than during 2010; however, groundwater flow directions in each of the areas showed little change.
Changes were also noted in groundwater quality in the Upper Floridan aquifer in parts of the state. In the Albany area, nitrate as nitrogen concentrations monitored near a public supply well field generally decreased during 2010-2011, with most wells within U.S. Environmental Protection Agency drinking-water standards. Concentrations in two of the wells, located about half a mile from the well field, remained above the EPA drinking-water standard.
In the Savannah area, data from two wells indicate that chloride concentrations in the Upper Floridan aquifer showed little change during calendar years 2010 through 2011 and remained within drinking-water standards. In the Brunswick area, the chloride concentration in the Upper Floridan aquifer remained above the drinking-water standard in an approximately two-square-mile area; however, chloride concentrations in 2011 were lower than in 2010 in over 70 percent of the wells sampled.
Groundwater levels, permitted water use, and groundwater quality throughout Georgia were summarized in a recently released report, "Groundwater conditions in Georgia, 2010-2011" by Michael F. Peck, Debbie W. Gordon, and Jaimie A. Painter, available online.
Up-to-date data for wells included in the report are available at the Georgia groundwater website.
LARAMIE, Wyo. — The mere presence of wolves, previously shown to affect the behavior of elk in the greater Yellowstone ecosystem, is not potent enough to reduce the body condition and reproductive rates of female elk, according to new research published today.
The research, led by recent University of Wyoming Ph.D. graduate Arthur Middleton, provides the most comprehensive evidence to date refuting the idea that wolves are capable of reducing elk calf recruitment indirectly through predation risk. The findings were published in the scientific journal Ecology Letters.
"Elk respond to wolves, but less strongly and less frequently than we thought," says Middleton, who for three years closely followed the Clarks Fork elk herd west of Cody, along with the wolf packs that prey on it. "We found that wolves influence elk behavior, but the responses were subtle and -- over the course of winter -- did not reduce body fat or pregnancy. Our work indicates that the effect of wolves on elk populations is limited to direct predation and doesn't include so-called harassment, stress and fear, which have been proposed as additional indirect effects on prey populations."
Working as part of the Wyoming Cooperative Fish and Wildlife Research Unit -- a U.S. Geological Survey program housed at UW in cooperation with the Wyoming Game and Fish Department -- Middleton and colleagues used state-of-the-art GPS collars and firsthand observation to track the interactions of the Clarks Fork herd with wolves from the Sunlight, Hoodoo, Beartooth and Absaroka wolf packs in 2008, 2009 and 2010. The detailed movement data on both wolves and elk allowed the researchers to identify each time one of the collared elk encountered a collared wolf. The elk herd, one of several migratory herds in the greater Yellowstone area, spends summers in Yellowstone National Park and moves into the Sunlight Basin during winter. The researchers also recaptured GPS-collared elk at the end of winter and the end of summer each year to assess their annual fat dynamics and pregnancy rates using ultrasonography.
The research found that when wolves approached within 1 kilometer (a little over a half mile), elk increased their rates of movement, displacement and vigilance. However, the behaviors only lasted about 24 hours and didn't significantly reduce elk foraging or force elk into poor habitats. And such encounters with wolves took place at a rate of only one in nine days on average for the migratory elk in the Clarks Fork herd -- the maximum was once every four days.
The key finding of the study is that even though elk varied widely in their encounters with wolves, those that encountered wolves frequently were not less fat -- or any less likely to be pregnant -- than those that rarely bumped into the predators. This finding differs from some previous studies that indicated wolves influence elk behavior strongly enough to contribute to regionwide declines in calf production.
"Our research was unique in that we tracked wolves while also monitoring the movements, foraging behavior, body fat and pregnancy of the elk they hunted," says Middleton, who worked under Matt Kauffman, head of the Wyoming Cooperative Fish and Wildlife Research Unit working under a dual appointment with the USGS and the UW's Department of Zoology and Physiology where he is an assistant professor. "This approach, essentially connecting the dots from wolf movements all the way to elk behavior and nutrition, revealed that elk respond to wolves too weakly and too infrequently for those behaviors to carry nutritional costs."
The study casts additional doubt on the idea that wolf reintroduction has caused what scientists call a "behaviorally mediated trophic cascade" in the greater Yellowstone ecosystem -- prompting elk to alter their foraging behavior or avoid risky areas, thereby allowing aspen and willows to recover from overbrowsing. These new findings are consistent with studies by Kauffman and others showing little or no evidence for cascading effects caused by purported broad-scale shifts in elk habitat use or foraging behavior in response to wolves.
Both Middleton and Kauffman have pointed out in their studies that the wide-ranging hunting strategy of wolves, which differs from the tactics of a stalking predator, might be the reason that elk responses are too weak and inconsistent to alter their foraging patterns or nutritional gain.
"A key factor in the ability of predators to cause these sorts of cascading effects is the ways in which they hunt and kill their prey," says Kauffman, who initiated the study in 2006 along with Game and Fish Department wildlife biologist Doug McWhirter and U.S. Fish and Wildlife Service wolf manager Mike Jimenez. "Wolves are coursing predators that chase down their prey, as opposed to stalking predators that lurk in concealed areas. We are learning that coursing predators are less likely to induce strong behavioral responses in their prey, and this new work suggests that the coursing hunting mode of wolves may constrain both their ability to influence prey condition and cause cascading ecological effects on plants."
Kauffman adds that the concept of non-consumptive effects of predators on prey has been well tested in small, well-controlled environments -- often involving insect predators and prey -- but that researchers are still sorting out how it all works in the large landscapes occupied by species such as wolves and elk.
Calf production has been declining among migratory elk herds in the greater Yellowstone area, but wolves may not be the primary culprit, Middleton says. For the Clarks Fork herd at least, other recent research findings point to high rates of bear predation and reduced habitat quality due to drought -- both on summer ranges largely inside Yellowstone -- as being the more likely cause of declines in elk calf numbers.
"The recovery of large carnivores, particularly grizzly bears, has brought major increases in predation on newborn elk during early summer," wrote Middleton, who added that the region has experienced severe drought and warmer temperatures in recent years. "These effects of drought and predation could largely explain both low pregnancy and declining calf production among elk of the Yellowstone region."
Kauffman, a USGS scientist, is one of the co-authors of the report published today -- along with a collaborative team of researchers from the Game and Fish Department, the Fish and Wildlife Service, the National Council for Air and Stream Improvement, Yellowstone National Park and UW.
The article summarizing the research in Ecology Letters is available online.
TACOMA, Wash. — USGS scientists took high-tech sensors typically found in devices such as smart phones and embedded them into a new method to monitor riverbed movements that can help protect spawning habitat for endangered salmon. Developed in cooperation with Seattle Public Utilities for the Cedar River, the new method is published in the Journal of Hydrology.
Seattle Public Utilities manages the Cedar River for about 70 percent of Seattle's drinking water, limited flood control, and to provide beneficial conditions for instream resources including spawning habitat for several species of salmon and trout. During spawning, female fish dig depressions in the gravel, called "redds," where they lay their eggs to incubate and hatch. Several species lay eggs around the fall-winter flood season. To protect the water supply, endangered Chinook salmon, steelhead trout, bull trout and 80 other species, the City of Seattle is implementing the 50-year, Cedar River Watershed Habitat Conservation Plan. As part of the plan, Seattle works with the interagency Cedar River Instream Flow Commission to provide beneficial stream flows in the 35 miles of river downstream of Chester Morse Reservoir.
High-tech sensors called "accelerometers" are used in smart phones, for example, to detect a change in phone movement, such as turning it to get a wider view. Scientists took accelerometers, coupled with data-logging circuits, and placed them in tubes that were then buried in the Cedar River's gravel in 26 salmon-spawning locations, at about the same depth in the gravel as salmon bury their eggs. During the 2010-11 flood season, when Cedar River high flows began moving gravel, the accelerometers tilted as the river moved them, too. The accelerometers automatically recorded the time of tilt, which scientists could relate to how much flow was in the river then, based on recorded USGS streamflow data.
"This is a great method to capture hard-to-get data that is so important to river management," said Andy Gendaszek, USGS hydrologist and lead author of the journal article. "From this study, we learned at what flow the river begins to scour, or move gravel. We found that most scour occurs at or before the peak of a flood."
The journal article, "The timing of scour and fill in a gravel-bedded river measured with buried accelerometers," by Andrew S. Gendaszek, Christopher S. Magirl, Christiana R. Czuba, and Christopher P. Konrad, is published in the Journal of Hydrology, and available online. It is available as a PDF file and printed copies will be available in July 2013.
LARAMIE, Wyo. — Migratory elk are coming back from Yellowstone National Park with fewer calves due to drought and increased numbers of big predators – two landscape-level changes that are reducing the benefits of migration with broader implications for conservation of migratory animals, according to a new study published in the journal Ecology.
The new study by the Wyoming Cooperative Fish and Wildlife Research Unit – a joint program involving U.S. Geological Survey, the University of Wyoming, and the Wyoming Game and Fish Department, describes a long-term decline in the number of calves produced annually by the Clarks Fork herd, a population of about 4000 elk whose migrants travel annually between winter ranges near Cody, Wyoming and summer ranges within Yellowstone National Park. Migratory elk experienced a 19 percent depression in rates of pregnancy over the four years of the study and a 70 percent decline in calf production over 21 years of monitoring by the WGFD, while the elk that did not migrate, known as resident elk, in the same herd experienced high pregnancy and calf production and are expanding their numbers and range into private lands outside of the park.
"This is one of North America's wildest and best-protected landscapes, where elk and other ungulates still retain their long-distance seasonal migrations – and yet it is the migratory elk that are struggling while their resident counterparts thrive in the foothills," said Arthur Middleton, who led this work as a University of Wyoming doctoral student and is now a postdoctoral fellow at the Yale School of Forestry and Environmental Studies.
A key finding of the study was that only 70 percent of migratory elk were pregnant, compared to 90 percent of residents – a rate more typical of Rocky Mountain elk. The study shows that the hotter and dryer summer conditions of the last two decades, coincident with the long-term drought widely affecting the West, has reduced the duration of the spring period when tender new grasses are available to elk. This makes it harder for female migratory elk to find the forage they need to both nurse a calf and breed. Though elk typically bear a calf every year, migratory elk that nursed a calf had only a 23 percent chance of becoming pregnant again in the following year.
Another likely cause of the declining calf numbers among migrants was predation. Migrants share their range with four times as many grizzly bears and wolves than resident elk, and both predators are well known to prey on young elk calves. Resident elk get a break from high levels of predation in part because when predators kill livestock on the resident range, they are often lethally removed by wildlife managers and ranchers.
"A lower pregnancy rate reduces the number of calves that are born in the first place, then predation seems to reduce the number of migratory calves that survive the first few months of life," said Matthew Kauffman a research wildlife biologist with the USGS and Assistant Professor at the University of Wyoming. Kauffman goes on to explain that resident elk numbers are growing in the foothills not because migrants are choosing to stay behind, but rather because irrigated fields and lower predator numbers are allowing residents to raise more calves to adulthood.
Globally, wildlife migration is a dwindling phenomenon. Research and management often focus on conspicuous barriers like fences, roads, and other kinds of development that can physically impede migration corridors. While those are important, this study suggests that even in a landscape as well-protected as the Greater Yellowstone Ecosystem, subtler changes in predator management and forage quality on the seasonal ranges of migratory animals will also play an important role. Migration is conventionally understood as a strategy to gain better forage quality while also reducing exposure to denning predators, but in this case, it seems those benefits are instead being realized by the residents.
The study's authors note that their work does not predict that migratory elk will disappear, but rather that there could be a long-term shift underway in the relative abundance of migratory versus resident elk in the system. The study also highlights the perils of characterizing Yellowstone wolf re-introduction as a "natural experiment." Other key factors have changed since wolves were re-introduced, including growth in grizzly bears numbers and recurrent long-term drought associated with reduced snowpack and hotter summers. The authors caution that such factors should be taken into account in the effort to understand ongoing ecological changes in Yellowstone.
Middleton also points out that this work highlights the complex challenges facing regional wildlife managers and other stakeholders as they continue to adapt to the reintroduction and recovery of large carnivores, and severe drought that some studies suggest is linked to longer-term climate change. "Most immediately, these trends have meant lost hunting opportunity in the backcountry areas frequented by migratory elk, and increasing crop damage and forage competition with domestic livestock in the frontcountry areas where resident elk are expanding," said Middleton.
This work was a collaboration among the USGS’s Wyoming Cooperative Fish and Wildlife Research Unit, the WGFD, and the U.S. Fish and Wildlife Service, with cooperation from YNP and other agencies. Primary funders include the WGFD, the Rocky Mountain Elk Foundation, the Wyoming Animal Damage Management Board, the Wyoming Governor’s Big Game License Coalition, and USGS, among others.
The study is featured in a Forum section of Ecology, with a series of commentaries from other ecologists who study wildlife migration and predator-prey interactions.
Funding from the USGS National Climate Change and Wildlife Science Center contributed to this study.
A unique deposit of heavy rare earth elements at Alaska's Bokan Mountain could help scientists understand how rare earth element deposits form, according to new research by geologists from Saint Mary's University in Halifax and the U.S. Geological Survey. Rare earth elements are important, but scarce, elements used in components in many cutting edge electronic and defense technologies.
Currently, very little is known about the geologic setting in which REE deposits form. Understanding these geologic settings and how they come to be is a crucial step to being able to determine where mineable concentrations of REE might be found.
REE are made up of 17 elements, including Yttrium, Scandium, and the 15 members of the Lanthanide series. They are divided into light and heavy REE, depending on their atomic weights. Light REE are more commonly dominant in REE deposits, which is why HREE-enriched deposits at Bokan Mountain are noteworthy.
HREE are very valuable for producing tiny high-grade magnets used in smart phones and tablets, and for increasing the ability of engines and transmissions to operate at higher temperatures. Bokan Mountain is one of the few known deposits where heavy rare earth elements are concentrated and can be more efficiently produced.
"Our work in southeastern Alaska has demonstrated the potential for a viable, world-class supply of heavy rare earths from a domestic source. The collaboration between the USGS, universities and Ucore Rare Metals is an excellent example of how public-private partnerships can directly succeed in assisting significant economic growth," said lead author Dr. Jaroslav Dostal, with Saint Mary's University in Halifax, Nova Scotia.
To determine how these deposits formed at Bokan Mountain, Dostal analyzed the granite using geochemistry and isotopic analysis, and then compared his results to other granites.
He found that the granite of Bokan Mountain is similar to granites that formed in what is known as a "rift setting," in which the Earth's crust splits apart and magma wells up from below. This magma then cools to form a distinctive type of granite.
USGS geologist Susan Karl mapped the structures in the Bokan Mountain granite and the rocks that the granite intruded. Her studies indicate the granite magma was emplaced on active structures associated with rifting.
"This research contributes to more efficient exploration for REE deposits," said Karl, who is located at the USGS Alaska Science Center in Anchorage. "By knowing more about how REE deposits form, scientists and mining companies can more accurately target rocks that might contain mineable concentrations of these critical minerals."
In 2010, USGS completed a report characterizing the principal REE deposits in the United States, including Bokan Mountain, AK and Mountain Pass, CA, which is the largest known deposit of REE in the United States. At the present time, the United States obtains its REE raw materials from foreign sources, almost exclusively from China. Import dependence upon a single country raises serious issues of supply security. This study will help to define domestic supply in the United States.
The USGS Mineral Resources External Research Program funded this research in 2009 with a grant to Saint Mary's University where Dostal is a professor emeritus. The USGS MRERP grant program is designed to support academic studies of topics such as the genesis of certain types of mineral deposits and make the information available to the general public, including the resource community and land stewards.
The USGS Mineral Resources Program delivers unbiased science and information to understand mineral resource potential, production, consumption, and how minerals interact with the environment.
In addition to his long career on the faculty at Saint Mary's University, Dostal also sits on the board of UCORE, the company that is currently developing the property at Bokan Mountain.
The report "Bokan Mountain peralkaline granitic complex, Alexander terrane (southeastern Alaska): Evidence for Early Jurassic rifting prior to accretion with North America" has been published in the Canadian Journal of Earth Sciences.
For more on this report and other USGS research on rare earth elements, please visit the USGS Rare Earths page. For more information on USGS mineral research, please visit the USGS Mineral Resources Program.
LITTLE ROCK, Ark. -- Intense rainfall in western Arkansas early Friday morning resulted in the Fourche LaFave River near Gravelly reaching record levels. The river level caused by the flooding – 32.6 feet – was the highest peak the streamgage at this site has measured since the U.S. Geological Survey began recording water-level stages and flow at this site in 1939. Prior to the rain the river was measuring 2.34 feet at that location.
"Engineers on my staff have calculated that there was less than a one percent chance of a flood of this magnitude occurring in a given year, and the probability may have been as low as 0.2 percent, putting this in the realm of a 500-year flood at this specific site near Gravelly, Arkansas," stated David Freiwald, Director of the USGS Arkansas Water Science Center in Little Rock. A "500-year flood" event does not necessarily occur once every 500 years, rather each year there is a 0.2 percent chance of a flood of this magnitude occurring.
The USGS sent crews out to measure flow and collect water samples in other parts of western and central Arkansas throughout the weekend. "We had as many as five crews out this weekend sampling the water quality of runoff and measuring storm flow," said Bill Baldwin, USGS chief at the Little Rock Field Office. "We began sampling and measuring early Friday morning on the smaller tributaries and will wind down later this week as the flow makes its way down the Arkansas and White rivers."
The USGS monitors stage and flow in more than 160 locations in Arkansas and collects water-quality samples at many of these locations. Some of the stations provide pertinent information to the National Weather Service and are used as part of a flood-warning information system. "The stations that serve as flood warning stations, such as the network of gages in Hot Springs, are the highest priority for USGS crews," noted Baldwin. "Where these gages are located, we have crews nearby so that if a station goes down from lightning or flooding, we can get it up and running as quickly as possible," he added.
Easily understandable near real-time stage and streamflow information is updated via satellite every hour, and occurs even more frequently for flood warning information gages – this information is available on the USGS Arkansas Water Science Center’s home page. The USGS uses data from its more than 160 streamgaging stations in Arkansas to operate several flood warning information systems. These systems are in operation in Hot Springs, Hardy, Benton and Batesville and are funded in cooperation with local and federal agencies. Most of these flood warning systems automatically call emergency management officials, including the National Weather Service, when certain rainfall amounts or water levels are reached, information that can help save lives and property.
Residents interested in signing up to receive email or text alerts when a streamgage reaches a predetermined parameter, such as water height, can subscribe to WaterAlert, a free service from the USGS.
Landscape change in Pennsylvania's Fayette and Lycoming counties resulting from construction of well pads, new roads and pipelines for natural gas and coalbed methane exploration is being documented to help determine the potential consequences for ecosystems and wildlife, according to a U.S. Geological Survey report released today.
Using geospatial data and high resolution aerial imagery from 2004-2010, USGS researchers documented spatially explicit patterns of disturbance, or land use, related to natural gas resource development, such as hydraulic fracturing, particularly disturbance patterns related to well pads, roads and pipeline construction.
Spatially explicit data on the level of landscape disturbance -- which is geographic information systems data, mapped to a high degree of spatial accuracy -- is critically important to the long-term study of the potential impacts of natural gas development on human and ecological health.
Through programs such as the National Land Cover Database, and Land Cover Trends, USGS has a long record of studying the consequences of land-use and land-cover changes. The current level of natural gas development in much of the country, and its effects on the landscape, is an important contemporary land-use/land-cover issue.
"Large-scale landscape disturbance can have a significant impact on ecological resources and the services they provide. This study provides a quantitative look at the levels of disturbance, forest loss and other changes to land use and land cover," said Terry Slonecker, lead author of the research.
Data from this report will be used to assess the effects of disturbance and land-cover change on wildlife, water quality, invasive species and socioeconomic impacts, among other investigations.
The study found that in Fayette County, 1297 natural gas extraction sites resulted in more than 1765.1 hectares of disturbance, including 466.9 kilometers (290 miles) of new roads and 3.7 kilometers (2 miles) of new pipelines. Disturbance in Fayette County occurs on the western side of the county.
In Lycoming County, 83 natural gas extraction sites resulted in more than 421 hectares of disturbance, including 37 kilometers (22 miles) of new roads and 73.7 kilometers (45 miles) of new pipelines. Disturbance in Lycoming County is scattered with most of it occurring in clusters in the eastern and western edges of the county.
The study, "Landscape consequences of natural gas extraction in Fayette and Lycoming Counties, Pennsylvania, 2004-2010," by E.T. Slonecker, L.E. Milheim, C.M. Roig-Silva, A.R. Malizia, and B.H. Gillenwater Open File Report 2013-1119, is the fourth of a series planned relating to natural gas landscape disturbance and is available online.
A Baseline Environmental Report (BER) newly released by the U.S. Geological Survey will provide a consistent set of information about the Greater Sage-Grouse. The report is one of a suite of documents that will help guide the Bureau of Land Management (BLM) and the U.S. Forest Service (USFS) in their joint efforts to conserve Greater Sage-Grouse.
"This report summarizes several decades of work on sage-grouse populations and sagebrush habitat. It will serve as a useful tool for land and wildlife managers and provides a needed range-wide perspective," said Suzette Kimball, Acting Director of the USGS.
The BLM and the USFS are preparing Environmental Impact Statements to address the effects of implementing proposed Greater Sage-Grouse conservation measures on the lands they manage. The agencies will use the BER in summarizing the effect of their joint planning efforts intended to help conserve the bird and its sagebrush habitat across its range in the western United States.
The report, assembled, peer reviewed and published by the USGS, is intended to provide a framework for considering potential implications and management options, and demonstrate a regional context and perspective needed for local planning and decision-making.
The BER looks at each of the threats to Greater Sage-Grouse identified in the U.S. Fish and Wildlife Service’s (FWS) "warranted but precluded" finding for listing the species under the Endangered Species Act. For these threats, the report summarizes the current scientific understanding of various impacts to Greater Sage-Grouse populations and habitats. The report also covers the location, magnitude, and extent of each threat. The BER does not provide management options.
The data for this report were gathered from BLM, USFS, and other sources. All data, both internal and external, were the "best available" at the range-wide scale at the time collected. At the conclusion of the 2012 fire season, the BER’s wildland-fire statistics were updated.
The BER report joins two other key documents being used by the agencies to prepare and evaluate their conservation plans, the BLM’s National Technical Team Report (NTT report) and the FWS's Conservation Objectives Team (COT) report. The NTT report provides habitat management recommendations for species across its entire range with detailed input by management zone, from State and local experts. The COT Report identifies conservation objectives and measures for each of the habitat threats assessed. For some threats, the team identified examples of actions that could be used to help attain the conservation objectives.
WASHINGTON -- NASA transferred operational control Thursday of the Landsat 8 satellite to the U.S. Geological Survey (USGS) in a ceremony in Sioux Falls, S.D.
The event marks the beginning of the satellite's mission to extend an unparalleled four-decade record of monitoring Earth's landscape from space. Landsat 8 is the latest in the Landsat series of remote-sensing satellites, which have been providing global coverage of landscape changes on Earth since 1972. The Landsat program is a joint effort between NASA and USGS.
NASA launched the satellite Feb. 11 as the Landsat Data Continuity Mission (LDCM). Since then, NASA mission engineers and scientists, with USGS collaboration, have been putting the satellite through its paces -- steering it into its orbit, calibrating the detectors, and collecting test images. Now fully mission-certified, the satellite is under USGS operational control.
"Landsat is a centerpiece of NASA's Earth Science program," said NASA Administrator Charles Bolden in Washington. "Landsat 8 carries on a long tradition of Landsat satellites that for more than 40 years have helped us to learn how Earth works, to understand how humans are affecting it and to make wiser decisions as stewards of this planet."
Beginning Thursday, USGS specialists will collect at least 400 Landsat 8 scenes every day from around the world to be processed and archived at the USGS Earth Resources Observation and Science Center in Sioux Falls. The newest satellite joins Landsat 7, which launched in 1999 and continues to collect images. Since 2008, USGS has provided more than 11 million current and historical Landsat images free of charge to users over the Internet.
"We are very pleased to work with NASA for the good of science and the American people," said U.S. Interior Secretary Sally Jewell in Washington. "The Landsat program allows us all to have a common, easily accessible view of our planet. We are especially proud that Landsat images have not only been the starting points for some of the world’s best commercial innovations in earth imagery, but also are available free of charge."
Remote-sensing satellites such as the Landsat series help scientists observe the world beyond the power of human sight, monitor changes to the land that may have natural or human causes, and detect critical trends in the conditions of natural resources.
The 41-year Landsat record provides global coverage at a scale that impartially documents natural processes such as volcanic eruptions, glacial retreat and forest fires and shows large-scale human activities such as expanding cities, crop irrigation and forest clear-cuts. The Landsat Program is a sustained effort by the United States to provide direct societal benefits across a wide range of human endeavors including human and environmental health, energy and water management, urban planning, disaster recovery, and agriculture.
With Landsat 8 circling Earth 14 times a day, and in combination with Landsat 7, researchers will be able to use an improved frequency of data from both satellites. The two observation instruments aboard Landsat 8 feature improvements over their earlier counterparts while collecting information that is compatible with 41 years of land images from previous Landsat satellites.
Multiple sources of Alaskan geochemical information have united into one online resource.
Alaska Geochemical Database Version 2.0 (AGDB2)—Including "Best Value" Data Compilations for Rock, Sediment, Soil, Mineral, and Concentrate Sample Media, is now available, and is the first database of its kind in the United States.
"We welcome the release of the second version of the Alaska Geochemical Database (AGDB2). The incorporation of the "best value" data compilation will be a great asset to all users," said Melanie Werdon, Geological Scientist, Mineral Resources, Alaska Division of Geological & Geophysical Surveys. "The determination by the USGS of which geochemical analysis is most quantitatively accurate, for each sample with multiple analyses, will save database users significant time, money, and effort,"
The database contains all USGS geochemical data for more than 264,000 samples collected between 1962 and 2009 from the State of Alaska. Each sample has one "best value" determination for each analyzed species, greatly improving speed and efficiency of use for this ArcGIS-friendly database.
"The "best value" feature is what makes the AGDB2 such an advancement over the AGDB of 2011. We are currently using the AGDB2 to map in ArcGIS over 35 elements for the entire State of Alaska," said Matthew Granitto, USGS scientist and primary author.
Contaminants such as polycyclic aromatic hydrocarbons (PAHs) found at low concentrations in southeast Wisconsin streams may be harmful to aquatic life, according to a study published today by the U.S. Geological Survey.
Scientists with the USGS and the Milwaukee Metropolitan Sewerage District (MMSD) detected 64 organic waste compounds, or micropollutants—including PAHs, fire retardants, fuels, herbicides, insecticides, antimicrobial disinfectants, detergent byproducts, flavors/fragrances, and non-prescription human drugs—in stream sediment, stream water, and harbor water samples collected in and around Milwaukee, Wisc., between 2006 and 2009.
“In general, concentrations were low and similar to those found in other studies around the U.S.,” said Austin Baldwin, USGS scientist and lead author of the study. “However, samples from some sites had concentrations high enough to potentially affect aquatic organisms.”
One or more of the compounds were detected in all 196 samples collected, with most samples having 12 or more. The Kinnickinnic River had the highest detection rates and concentrations of compounds of all the 17 sampled sites, while the Milwaukee River near Cedarburg and the Outer Milwaukee Harbor had the lowest. The study found that, overall, urban stream samples were more contaminated than rural samples in the Milwaukee area.
The most common and highly concentrated compounds detected in the study were PAHs. In sediment samples from several streams, and in water samples collected during runoff periods from several streams, PAH concentrations were shown to be greater than levels considered harmful to aquatic life.
Common sources of PAHs include coal-tar-based pavement sealants, coal-fired power plants, wood burning, and vehicle emissions. The USGS and MMSD are planning a follow-up study focused on identifying the major sources of PAHs to streams to help guide future watershed management decisions.
The MMSD has been funding the monitoring of micropollutants in area waterways since 2004, and has taken a number of steps to minimize them, including sponsoring household hazardous waste and medicine collection programs. Since the inception of these two programs, over 7,000 tons of household hazardous waste and 21 tons of unused medicine have been collected and properly disposed.
Chemicals used in agriculture, industry, and households—including those detected in the USGS study—make their way into surface waters through stormwater runoff, atmospheric deposition, leaking sanitary-conveyance systems, improperly functioning septic systems, regulated and unregulated discharges, combined sewer overflows, and improper disposal such as people dumping oil down storm sewers.
Many of these compounds are toxic at elevated concentrations and known to have endocrine-disrupting potential, which means that they could interfere with animals’ hormone systems and potentially cause cancer, birth defects, or other disorders.
The study also analyzed sediment and water samples for 27 known or suspected endocrine-disrupting chemicals. All but three of the chemicals were detected at least once, with most samples containing four or more.
Other compounds with high detection rates and/or concentrations included caffeine; the herbicides Atrazine and Dichlorophenyl isocyanate; the insecticide Carbazole; Anthraquinone, which is a pigment; Tris (2-butoxyethyl) phosphate, a fire retardant; and Nonylphenol, which may come from a number of sources including detergents.
For more information, please visit the USGS Wisconsin Water Science Center website.
Turtles dine in waters affected by oil spills, fishing and oxygen depletion
CORPUS CHRISTI, Texas – The favored feeding grounds of the endangered Kemp’s ridley sea turtle coincide with some Gulf of Mexico waters that are subject to oil spills, extensive commercial fishing and oxygen depletion.
These first-of-their kind details on foraging locations and migration patterns of the Kemp’s ridley sea turtle are from a new National Park Service and U.S. Geological Survey study, providing resource managers new information on how best to manage the species.
Scientists do not know why the turtles feed where they do, how human influences may affect turtle health or behavior, or whether human impacts on their chosen feeding areas might change their future foraging behavior.
The researchers identified the feeding grounds of the Kemp’s ridley, considered the most endangered and smallest hard-shelled sea turtle in the world, by analyzing 13 years of satellite-tracking data. The researchers tagged turtles at nesting sites between 1998 and 2011 and tracked them as they went on to foraging locations throughout the Gulf. Turtles from two major nesting sites in the study fed at specific locations off the coasts of Louisiana and Mississippi and at other locations in the Gulf.
Donna Shaver, chief of the National Park Service’s Sea Turtle Science and Recovery Division at Padre Island National Seashore, said, “Protecting feeding grounds for adult female sea turtles is important for the recovery of the species and this new information is important for future planning and restoration decisions.”
Cooperative efforts between Mexico and several U.S. agencies have helped increase the population of this species of sea turtle. Species support includes protection of nesting turtles and their eggs on nesting beaches and reducing threats from fishing. The number of Kemp’s ridleys nesting in the region has increased from 702 nests in 1985 to about 22,000 in 2012.
The research, in which dozens of adult female sea turtles were tagged after they nested on the beach at Padre Island National Seashore offers a “first glimpse” of how and when the turtles feed, said Kristen Hart, a research ecologist for the USGS Southeast Ecological Science Center. “We were able to decipher Kemp’s ridleys foraging behavior in space and time using a combination of satellite telemetry and new statistical techniques.”
Previous tracking studies generally showed Kemp’s ridley migration from nesting beaches along the Gulf of Mexico coastline to northern Texas and Louisiana with some turtles migrating as far as peninsular Florida. Until the current study, it was not known whether turtles displayed movement behavior indicative of foraging or migration at a particular location. The modeling done as part of the study has allowed scientists to pinpoint where these turtles may be feeding, a key finding in terms of identifying important at-sea habitats for these imperiled turtles.
In addition to tagging turtles at Padre Island, Shaver said the researchers tagged turtles at nesting sites in Rancho Nuevo, Mexico, about 200 miles south of Padre Island. Shaver added, “This is the first time we’ve tracked the Mexican turtles to habitats in the Northern Gulf of Mexico.”
The feeding habitat discovery came when scientists differentiated time the sea turtles spent in feeding or breeding mode from the time spent migrating. Once scientists located when and where the turtles were feeding, they were also able to coarsely profile what type of habitat offered the best feeding grounds for Kemp’s ridleys.
“We have a lot more to learn about how and why Kemp’s ridleys use their foraging sites,” Hart said. “We don’t know enough about individual turtles yet to draw conclusions about their behavioral responses to conditions at foraging grounds, and we are just beginning to understand differences among different sea turtles species. For example, Kemp’s ridleys appear to migrate, then feed, and then migrate to a final feeding destination. Loggerheads, in contrast, seem to head straight for feeding hotpots.”
Hart added, “We plan to continue fleshing out the major scientific gaps that managers need addressed in order to develop long-term survival and recovery plans for Kemp’s ridleys.”
Read the study, “Foraging area fidelity for Kemp’s ridleys in the Gulf of Mexico,” in the journal Ecology and Evolution.
About Kemp’s Ridley sea turtles
The Kemp''s ridley turtles are considered the smallest sea turtle in the world, with adults reaching about 2 feet long and weighing up to 100 pounds. They are found in the Gulf of Mexico and the Atlantic seaboard and feed primarily on crab species living on the sea floor (or benthos) of shallow waters. Their name comes from a fisherman named Richard Kemp of Key West, Florida, who provided the specimen used to describe the species in 1880. They are related to olive ridleys, another small sea turtle found around the world.
Kemp’s ridley sea turtles are listed in the U.S. and internationally as endangered throughout their range due to dramatic population declines in the 20th century. The vast majority of Kemp’s ridleys converge on three major sites in the state of Tamaulipas, Mexico every year to nest. In the early 1960s, a film was discovered that showed an estimated 40,000 females nesting at one particular site – Rancho Nuevo – on one day.
Threats to Kemp’s ridleys once included egg collection, overhunting, and unintentional capture during fisheries operations. Today, most of their nesting occurs on protected lands. Nonetheless, nesting habitat is still sometimes disturbed by natural and human events such as hurricanes, oil spills, or erosion. Also, activities that affect the seafloor (what scientists call benthic habitat) can disturb their feeding habitat. This includes bottom trawling and dredging. Another known threat is incidental capture, or unintentional by-catch, in fishing gear.
Although conservation efforts began in the 1960s, the number of nesting females continued to decline. By 1978, the U.S. and Mexico started a multi-agency effort to safeguard Kemp’s ridleys from extinction by encouraging nesting at Padre Island National Seashore in Texas. Biologists have since been monitoring nesting activity, and there has been an increase in the number of nests since 1985.
About the National Park Service: More than 20,000 National Park Service employees care for America’s 401 national parks and work with communities across the nation to help preserve local history and create close-to-home recreational opportunities. Learn more at www.nps.gov.
North America's largest vulture, the California condor, once graced the skies of the Pacific Northwest from northern California to British Columbia and was deeply woven into the fabric of many Native American cultures. A new book by two federal scientists documents the condors history in the region, from prehistoric times to the early 20th century.
The book, "California Condors in the Pacific Northwest," was written by Jesse D'Elia, a wildlife biologist in the Endangered Species Division of the U.S. Fish and Wildlife Service, and Susan Haig, a wildlife ecologist with the U.S. Geological Survey, and is published by Oregon State University Press.
The authors explore the ancient fossil and modern living records, as well as the cultural relationships between Native American tribes and condors. They evaluate the probable causes of regional extinction, explore the likelihood that condors once bred in the region, and assess factors that might be considered in determining if condors could be reintroduced in the Pacific Northwest.
"The California condor is an iconic endangered species and one that captures our collective imagination," said D'Elia. "Reading through the first-hand accounts of early explorers encountering condors, it isn't hard to envision these giant birds once soaring through the skies of the Pacific Northwest in numbers. In addition to stirring our imagination, evaluating the history of condors in the region helps us understand where condors once occurred, how common they were, and why they disappeared. This is all crucial information for devising a science-based recovery strategy."
Haig said, "It was heartening to learn that condors were widely distributed in the Pacific Northwest and probably disappeared for reasons other than habitat loss – most likely their decline was caused by secondary poisoning. This underscores the importance of ongoing research about the availability of habitat and uncontaminated food sources in the modern Pacific Northwest landscape as conservation partners evaluate the role this region might play in condor recovery."
In the foreword to the book, wildlife ecologist Noel Snyder writes, "The re-creation of a viable population of condors in the Northwest would constitute an achievement of substantial importance. This book goes a long way toward justifying such an effort." Snyder was the U.S. Fish and Wildlife Service biologist in charge of condor research in the 1980s when the entire population numbered less than 30 birds.
The California condor is still one of the most endangered birds in the world, although efforts by the U.S. Fish and Wildlife Service and conservation partners to breed condors in captivity and release them have resulted in 234 wild condors living in California, Arizona, and Baja California, Mexico. Another 170 condors live in zoos and other captive situations. They remain absent from the northern half of their historic range.
While the U.S. Fish and Wildlife Service has no immediate plans to reintroduce condors to the Pacific Northwest, the agency is working with conservation partners to assess the feasibility and need for a California condor-release site in the region.
Copies of the book can be ordered online or by calling 1-800-621-2736.
The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. We are both a leader and trusted partner in fish and wildlife conservation, known for our scientific excellence, stewardship of lands and natural resources, dedicated professionals, and commitment to public service. For more information on our work and the people who make it happen, visit us online. Connect with USWF's Facebook page, follow their tweets, watch their YouTube Channel and download photos from their Flickr page.
COOK, Wash. — The Columbia River Gorge Commission and the United States Geological Survey have initiated an agreement that will put the Columbia River Gorge National Scenic Area in the vanguard locally and nationally with an innovative multi-agency resource management and community development partnership. The collaboration is focused on establishing a regional support system designed to help local, regional and federal decision makers better understand the overall economic, environmental, and cultural health of the Columbia River Gorge. It will also advance regional policy, improve resource management and guide community development. The Gorge Commission and USGS anticipate the system of objective, fact-based information will be a significant asset to every community in the Gorge.
When USGS top scientists working in the Columbia River Research Laboratory approached the Gorge Commission to discuss opportunities to partner on a project to strengthen the National Scenic Area's Vital Signs Indicators project, executive director Darren Nichols recognized its value. "The Vital Signs Indicators Project is a successful regional collaboration designed to measure the overall health of National Scenic Area resources and the Gorge economy. This partnership with scientists from the USGS and Northwest universities offers the region a tremendous opportunity to use the VSI for effective, efficient public decisions that will support and enhance the successful future of the Gorge," Nichols said.
In the beginning the partnership will work on building a high level "conceptual model" of the decision support framework. The initial model will be further developed and built into a fully functioning analytical decision tool for the National Scenic Area's resources and economy. In essence, the agencies envision a tool similar to the classic video game SimCity, where citizens, policy makers, elected officials and citizens can explore a variety of scenarios for the future of the Columbia Gorge and the types of decisions that will support a preferred future.
CRGC and USGS staff expect to have the first conceptual model developed this summer and will quickly seek funding and additional partners to work on the functional tools. Department directors and faculty of Washington State University, Portland State University, and Oregon State University have contributed to the scoping and planning of the effort and are expected to continue providing expertise to the model development process.
"USGS expertise in designing and implementing monitoring programs, coupled with our experience developing Decision Support Systems will enable us, and our academic partners, to make a significant contribution to this collaboration with the CRGC," said Steve Waste, director of the USGS Columbia River Research Laboratory, "The Commission is to be commended for initiating an innovative program relevant to both the region, and the nation."
Urban Seismic Studies to Begin in East San Francisco Bay Area
About 30 seismic sensors are seeking a place to hang out for up to three years in the greater Pleasanton/Dublin/San Ramon, Calif., area.
These sensors will help U.S. Geological Survey scientists conduct the next step in vital research to better understand how earthquakes behave in and around the East San Francisco Bay.
USGS scientists have been operating a number of urban seismic arrays in the East San Francisco Bay area since 1999. The sensors in these surveys are strong motion instruments, designed to trigger when signals from a nearby earthquake are detected. Arrays are currently operating in private homes and businesses in San Lorenzo, San Leandro, Niles and Pleasanton.
Bay Area residents may be acquainted with USGS NetQuakes – a program to increase the number of seismic stations to augment permanent regional seismograph networks in major cities such as San Francisco. In contrast to NetQuakes stations, the instrumentation in the urban arrays for this current study are not designed to connect to a communication system in order to transmit to the USGS National Earthquake Information Center for real-time earthquake monitoring; rather, triggered data is collected and stored on a local disk and retrieved by scientists during maintenance visits twice a year.
The placement of stations in the urban arrays are carefully planned to answer specific seismic hazards research questions. The distance between stations 'tunes' the array to detect particular seismic waves in a manner similar to the way radios detect different stations by changing the frequency of the signal receiver. The pattern or distribution of stations is designed to capture the spatial variability in ground motion or site response.
The urban array sensors are set to trigger at specific sensitivities that increase the likelihood that acquired data will be earthquake signals rather than other noise sources. Like the NetQuakes stations, scientists hope to capture earthquake data for events as small as magnitude 2.0. Site response observed from small events can help predict ground motion behavior in larger events.
USGS scientists will be in the area during the month of June 2013 to meet with interested hosts and answer any questions they may have prior to deployment of the instruments in August.
Interested parties may visit the Volunteer Monitoring website for more detailed information and images about the project as well as contacts.
CORVALLIS, Ore. — The first-ever estimate of how fast frogs, toads and salamanders in the United States are disappearing from their habitats reveals they are vanishing at an alarming and rapid rate.
According to the study released today in the scientific journal PLOS ONE, even the species of amphibians presumed to be relatively stable and widespread are declining. And these declines are occurring in amphibian populations everywhere, from the swamps in Louisiana and Florida to the high mountains of the Sierras and the Rockies.
The study by USGS scientists and collaborators concluded that U.S. amphibian declines may be more widespread and severe than previously realized, and that significant declines are notably occurring even in protected national parks and wildlife refuges.
"Amphibians have been a constant presence in our planet's ponds, streams, lakes and rivers for 350 million years or so, surviving countless changes that caused many other groups of animals to go extinct," said USGS Director Suzette Kimball. "This is why the findings of this study are so noteworthy; they demonstrate that the pressures amphibians now face exceed the ability of many of these survivors to cope."
On average, populations of all amphibians examined vanished from habitats at a rate of 3.7 percent each year. If the rate observed is representative and remains unchanged, these species would disappear from half of the habitats they currently occupy in about 20 years. The more threatened species, considered "Red-Listed" in an assessment by the global organization International Union for Conservation of Nature, disappeared from their studied habitats at a rate of 11.6 percent each year. If the rate observed is representative and remains unchanged, these Red-Listed species would disappear from half of the habitats they currently occupy in about six years.
"Even though these declines seem small on the surface, they are not," said USGS ecologist Michael Adams, the lead author of the study. "Small numbers build up to dramatic declines with time. We knew there was a big problem with amphibians, but these numbers are both surprising and of significant concern."
For nine years, researchers looked at the rate of change in the number of ponds, lakes and other habitat features that amphibians occupied. In lay terms, this means that scientists documented how fast clusters of amphibians are disappearing across the landscape.
In all, scientists analyzed nine years of data from 34 sites spanning 48 species. The analysis did not evaluate causes of declines.
The research was done under the auspices of the USGS Amphibian Research and Monitoring Initiative, which studies amphibian trends and causes of decline. This unique program, known as ARMI, conducts research to address local information needs in a way that can be compared across studies to provide analyses of regional and national trends.
Brian Gratwicke, amphibian conservation biologist with the Smithsonian Conservation Biology Institute, said, "This is the culmination of an incredible sampling effort and cutting-edge analysis pioneered by the USGS, but it is very bad news for amphibians. Now, more than ever, we need to confront amphibian declines in the U.S. and take actions to conserve our incredible frog and salamander biodiversity."
The study offered other surprising insights. For example, declines occurred even in lands managed for conservation of natural resources, such as national parks and national wildlife refuges.
"The declines of amphibians in these protected areas are particularly worrisome because they suggest that some stressors – such as diseases, contaminants and drought – transcend landscapes," Adams said. "The fact that amphibian declines are occurring in our most protected areas adds weight to the hypothesis that this is a global phenomenon with implications for managers of all kinds of landscapes, even protected ones."
Amphibians seem to be experiencing the worst declines documented among vertebrates, but all major groups of animals associated with freshwater are having problems, according to Adams. While habitat loss is a factor in some areas, other research suggests that things like disease, invasive species, contaminants and perhaps other unknown factors are related to declines in protected areas.
"This study," said Adams, "gives us a point of reference that will enable us to track what's happening in a way that wasn’t possible before."
The publication, Trends in amphibian occupancy in the United States, is authored by Adams, M.J., Miller, D.A., Muths, E., Corn, P.S., Campbell Grant, E.H., Bailey, L., Fellers, G.M., Fisher, R.N., Sadinski, W.J., Waddle, H., and Walls, S.C., and is available to the public.
Measuring the Forces Generated by Erosive Debris Flows
Diving deep into the mechanics of bedrock incision caused by debris flows, scientists now have a better understanding of the erosive forces responsible for cutting valleys into mountainous terrain, according to recently published research in the Journal of Geophysical Research-Earth Surface.
"Our field-based measurements shed new light on what is happening beneath fast-moving debris flows," said U.S. Geological Survey scientist Jeff Coe. "Debris flows carry large rocks and impacts from those rocks make the flows very efficient at carving bedrock from valleys bottoms."
Debris flows are fast-moving landslides that occur in a wide variety of environments throughout the world. They are particularly dangerous to life and property because they move quickly, destroy objects in their paths, and often strike without warning.
The new research provides an improved understanding of how mountain valleys are formed and a better idea of the rate of formation given the frequency of debris flows in the current climate.
"A possible extension of this work would be to incorporate the results into quantitative landscape evolution models that predict how landforms evolve through time given static, or changing climatic conditions. Improved knowledge of how landforms evolve is useful for hazard assessments and possibly for long-term, land use planning," said Coe.
For four years, scientists from the University of Colorado and USGS used specialized instruments installed at the Chalk Cliffs Natural Debris Flow Laboratory near Buena Vista, Colo. to monitor 11 naturally-occurring debris flows. During that time, they found that downward-directed impact forces beneath the flows caused about 30-60 millimeters (1.2 to 2.4 inches) of bedrock erosion.
The group observed the mechanisms by which the bedrock was removed by passing debris flows and determined the statistical distribution that best characterized the impact forces.
"We also found that a thin layer of sediment shielded the bedrock surface from debris-flow impacts and erosion," said Scott McCoy, lead author from the University of Colorado, now at the Massachusetts Institute of Technology. "Our measurements and statistical analyses provide a foundation for linking impact forces that cause erosion to easily measured debris flow properties."