USGS Newsroom

New Insight on Gas Hydrates in Gulf of Mexico

OC_Web@usgs.gov (Office of Communications and Publishing) — Tue, 14 May 2013 10:00:00 EDT

Research is Part of a Long-Standing, Interagency Collaboration

Scientists have returned from a 15‑day research expedition in the northern Gulf of Mexico with the best high-resolution seismic data and imagery ever obtained of sediments with high gas hydrate saturations.

The expedition and the data and imagery collected resulted from long-standing cooperation between the U.S. Department of the Interior's U.S. Geological Survey (USGS) and Bureau of Ocean Energy Management (BOEM) and the U.S. Department of Energy (DOE). This collaboration aims to advance scientific understanding of gas hydrates, an important potential future energy resource.

Gas hydrates are ice-like substances formed when certain gases combine with water at specific pressures and temperatures. Deposits of gas hydrates are widespread in marine sediments beneath the ocean floor and in sediments within and beneath permafrost areas, where pressure-temperature conditions keep the gas trapped in the hydrate structure. Methane is the gas most often trapped in these deposits, making gas hydrates a potentially significant source for natural gas around the world.

"This expedition represents a significant milestone," said USGS Energy Resources Program Coordinator Brenda Pierce. "The data and imagery provide insight into the entire petroleum system at each location, including the source of gas, the migration pathways for the gas, the distribution of hydrate-bearing sediments, and the traps that hold the hydrate and free gas in place. The USGS has a globally recognized research effort studying gas hydrates in settings around the world, and this project combines our unique expertise with that of other agencies to advance research on this potential future energy resource."

The recently completed expedition was planned jointly by USGS, DOE, and BOEM, and was executed by USGS. Using low-energy seismic sources, USGS scientists collected details about the nature of the gas hydrate reservoirs and about geologic features of the sediment between the reservoirs and the seafloor. The new data also provide information about how much gas hydrate exists in a much broader area than can be determined from using standard industry seismic data, which is typically designed to image much deeper geologic units.

"Understanding the nature and setting of deepwater gas hydrates is central to the National Methane Hydrates R&D Program, which is led by DOE and managed by Fossil Energy's National Energy Technology Laboratory," said Christopher Smith, DOE’s Acting Assistant Secretary for Fossil Energy. "Over the past 8 years, research carried out under this program has resulted in significant advances in our understanding of methane hydrates, their role in nature, and their potential as a future energy resource. This success is largely due to an unprecedented level of cooperation among federal agencies, industry, national laboratories, and academic institutions."

"The high-resolution nature of the data acquired through this interagency project will uniquely inform the BOEM effort to assess the resource potential of gas hydrates on the U.S. Outer Continental Shelf," said Renee Orr, Chief, Strategic Resources Office, BOEM.

The data were collected at two locations in the Gulf of Mexico where the three federal agencies partnered with an industry consortium to conduct a drilling expedition in 2009. That expedition discovered gas hydrate filling between 50 and 90 percent of the available pore space between sediment grains in sandy layers in the subsurface. These reservoirs are expected to be representative of the 6,700 trillion cubic feet of gas that BOEM estimates is housed in gas hydrates in sand-rich reservoirs in the northern Gulf of Mexico.

The new data are being used to refine estimates of the nature, distribution, and concentration of gas hydrate in the vicinity of the 2009 drill sites. This will help assess how useful specialized seismic data may be to estimating hydrate saturations in deepwater sediments.

In coming years, the three agencies will continue their collaborative investigation of gas hydrates in the northern Gulf of Mexico and other locations across the world.

Learn more about USGS research on gas hydrates and energy at locations around the world.

Stars show the locations of seismic surveys conducted to image previously-identified deepwater gas hydrate deposits in the northern Gulf of Mexico on the research ship Pelican during a cruise in April and May 2013. (Larger image)

This high-resolution image was collected during a seismic cruise to study locations with high concentrations of gas hydrate in the northern Gulf of Mexico in April and May 2013. The data were collected at the Walker Ridge location, where 2009 drilling at the site of the well (shown in red revealed) the distribution of gas hydrates and methane gas in the sediments. The water depth at the well is 6562 feet, and the red and blue colors shown within the image correspond to sediment layers, which mostly dip westward. Sand layers with high concentrations of gas hydrate are marked, but hydrate also occurs elsewhere in this sedimentary section. (Larger image)

Texas and New York New Maps Posted

OC_Web@usgs.gov (Office of Communications and Publishing) — Tue, 9 Apr 2013 8:00:00 EDT

The release of new maps covering Texas and New York continues the US Topo revisions, updates and product improvement

The newest sets of US Topo maps cover the states of Texas and New York. The 4,309 quadrangles for Texas and 972 quads covering New York replace the existing US Topo maps for those states, and will be added to the USGS Historical Topographic Map Collection. All of these maps are available for free download from The National Map and the USGS Map Store website.

Last September the USGS marked the important milestone of completing the initial round of US Topo map production for the 48 contiguous states. The agency is continuing to improve the US Topo map product, moving into the next round of national map revisions. Hawaii is currently in production and Alaska production will start later this year.

"The US Topo program is a dynamic product and the new maps over Texas and New York demonstrate our commitment to a very aggressive three year revision cycle while at the same time adding new content", said Mike Cooley, the US Topo Project Manager. "I encourage you to take a look at these maps and drop us a comment on how we are doing via our drop box, as your input is important to us."

New feature additions and improvements on the updated US Topo maps include:

Woodland tint derived from the National Land Cover Dataset
Fire stations
Hospitals
State and county boundaries
Forest service boundaries
Commercial roads in lieu of census roads
Forest Service roads and road numbers

US Topos are derived from key layers of geographic data found in The National Map, which delivers visible content such as high resolution aerial photography, which was not available on older paper-based topographic maps. The new US Topo maps provide modern technical advantages that support wider and faster public distribution and on-screen geographic analysis tools for users.

Future enhancements to the US Topo are scheduled to include additional tools and map content such as a shaded relief layer, updated structures, enhanced transportation, additional federal boundaries and Forest Service trails. Wyoming, which was added in the fall of 2012, also featured Public Land Survey System (PLSS). The USGS expects to produce more than 18,500 revised quadrangles annually. US Topo maps are updated every three years.

The new digital electronic topographic maps are delivered in GeoPDF image software format and may be viewed using Adobe Reader, available as a no cost download.

For more information, go to: http://nationalmap.gov/ustopo/

New USGS Report Updates Decline of High Plains Aquifer Groundwater Levels

OC_Web@usgs.gov (Office of Communications and Publishing) — Fri, 22 Feb 2013 7:48:52 EDT

The U.S. Geological Survey has released a new report detailing changes of groundwater levels in the High Plains Aquifer. The report presents water-level change data in the aquifer in two separate periods: from 1950–the time prior to significant groundwater irrigation development–to 2011, and 2009 to 2011.

In 2011, the total water stored in the aquifer was about 2.96 billion acre-feet, an overall decline of about 246 million acre-feet (or 8 percent) since pre-development. Change in water in storage from 2009 to 2011 was an overall decline of 2.8 million acre-feet. The overall average water-level decline in the aquifer was 14.2 feet from pre-development to 2011, and 0.1 foot from 2009 to 2011.

The study used water-level measurements from 3,322 wells for pre-development to 2011 and 7,376 wells for 2009 to 2011.

The High Plains Aquifer, also known as the Ogallala Aquifer, underlies about 112 million acres (175,000 square miles) in parts of eight states Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The USGS, at the request of the U.S. Congress, has published reports on water-level changes in the High Plains Aquifer since 1988. Congress requested these reports in response to substantial water-level declines in large areas of the aquifer.

This multi-state, groundwater-level monitoring program has allowed water-level changes in all eight states to be tracked over time and has provided data critical to evaluating different options for groundwater management. This level of coordinated groundwater-level monitoring is unique among major, multi-state regional aquifers in the country.

The report "Water-Level and Storage Changes in the High Plains Aquifer, Predevelopment to 2011 and 2009–11" is available online.

Gulf Coast Vulnerable to Extreme Erosion in Category 1 Hurricanes: New Model to Help Community Planners, Emergency Managers

OC_Web@usgs.gov (Office of Communications and Publishing) — Wed, 30 May 2012 8:30:00 EDT

Seventy percent of the Gulf of Mexico shoreline is vulnerable to extreme erosion during even the weakest hurricanes, according to a new report by the U.S. Geological Survey released just prior to the start of the 2012 hurricane season.

USGS scientists used state-of-the-art modeling to determine the probabilities of erosion, overwash and inundation during direct hurricane landfall for sandy beaches along the entire U.S. Gulf Coast shoreline.

The research is expected to help emergency managers at local, state and federal levels as they prepare for hurricane events in this and future seasons. Planners will be able to determine how different categories of hurricanes would impact their beaches and surrounding communities, helping them better protect lives and property. The report also includes an interactive map that allows users to focus on different parts of the Gulf Coast shoreline to view how the probability of erosion, caused by waves and storm surge, will vary depending on hurricane intensity.

"The Gulf Coast's beaches provide abundant recreational opportunities, contribute substantially to the local economy, and demand the highest real estate values," said USGS Director Marcia McNutt. "This important research raises awareness on the specific nature of the vulnerability of these beautiful beaches to impacts from even Cat-1 hurricanes so that property damage can be minimized through proper planning."

In a storm, high waves and storm surge can act together to erode beaches and inundate low-lying lands; during hurricane landfall, these changes can sometimes be catastrophic.

"Beaches along the Gulf of Mexico are extremely vulnerable to erosion during hurricanes, in part, because of low elevations along the coast," said Hilary Stockdon, a USGS research oceanographer and lead author of the study. "For example, the average elevation of sand dunes on the west coast of Florida is eight feet. On Florida’s Atlantic coast, the average is 15 feet."

During the landfall of a category-1 storm, where winds are between 75 and 94 miles per hour, overwash is very likely for 70 percent of Gulf Coast beaches. Overwash occurs when waves and storm surge overtop dunes and transport sand landward. Overwash is likely at these locations because of increased water levels at the shoreline. During category-1 hurricane events on the Gulf Coast, wave height and storm surge combine to increase water levels at the shoreline by 14 and a half feet higher than their normal levels.

"People continue to build communities in coastal areas that shift and move with each passing storm," said Stockdon. "This model helps us predict the potential impact of future storms and allows us to identify where the most vulnerable areas are located along the coast."

Additional findings from the report show that during a category-1 storm landfall, 27 percent of sandy beaches along the U.S. Gulf of Mexico are projected to be inundated, which occurs when increased water levels completely submerge beaches and dunes. If category-5 storms occur, where winds are 157 miles per hour or higher, 89 percent of these beaches are likely to be inundated during a direct landfall.

USGS scientists used methodology developed from a decade of USGS research on storm-driven coastal change hazards as the basis for these calculations. Observational data were combined with sophisticated hydrodynamic modeling to predict the coastal changes provided in the report. As new data and storm predictions become available, the report's analysis will be updated to describe how coastal vulnerability may change in the future.

Key findings and the full report are available online.

A similar report detailing erosion hazards along the east coast is planned later this year. This report will provide an assessment of vulnerability for east coast barrier island communities.

A Big Day for Science: Citizens Have Contributed One Million Observations to Top Nature Database

OC_Web@usgs.gov (Office of Communications and Publishing) — Thu, 3 May 2012 9:00:00 EDT

RESTON, Va. — Thanks to citizen-scientists around the country, the USA National Phenology Network hit a major milestone this week by reaching its one millionth nature observation.

The millionth observation was done by Lucille Tower, a citizen-scientist in Portland, Ore., who entered a record about seeing maple vines flowering. Her data, like all of the entries, came in through USA-NPN’s online observation program, Nature's Notebook, which engages more than 4,000 volunteers across the country to observe and record phenology – the timing of the recurring life events of plants and animals such as when cherry trees or lilacs blossom, when robins build their nests, when salmon swim upstream to spawn or when leaves turn colors in the fall.

Each record not only represents a single data point — the status of a specific life stage of an individual plant or animal on one day – but also benefits both science and society by helping researchers understand how plants and animals are responding to climate change and, in turn, how those responses are affecting people and ecological systems.

"My dream is that through the wonders of modern technology and the National Phenology Network we could turn the more than six billion people on the planet into components of our scientific observing system," said USGS Director Marcia McNutt. "We could make giant leaps in science education, improve the spatial and temporal coverage of the planet, lower the cost of scientific data collection, and all while making ordinary citizens feel a part of the scientific process."

Jake Weltzin, a U.S. Geological Survey scientist and the executive director of USA-NPN, concurs. "Hitting the one millionth observation is exciting because researchers and decision-makers need more information to understand and respond to our rapidly changing planet. More information means better-informed decisions that ensure the continued vitality of our natural areas that we all depend on and enjoy."

For example, said Weltzin, the data in Nature's Notebook are already being used to benefit society, including the development of more accurate indicators of spring, forecasting the onset of allergy seasons or the chances of western wildfires, managing wildlife and invasive plants, and setting goals for habitat restoration. Ultimately, such information can be used for better managing water resources, wildlife and ecosystem management, and even help farmers and ranchers across the nation.

Changes in phenology are among the most sensitive biological indicators of global change. Across the world, many springtime events are occurring earlier — and fall events happening later — than in the past. These changes are happening quickly for some species and more slowly, or not at all, for others, altering relationships and processes that have been dynamically stable for thousands of years. Some wildlife —like caribou and butterflies — are becoming mismatched from their plant food resources, which are responding differently. Migrations for some birds are changing too, as they can now overwinter instead of moving south for the winter, or as they fly north more quickly to keep pace with an advancing front of spring flowering.

Because of this, said Weltzin, scientists need more and better information about the pace and pattern of nature — locally to nationally — to answer important scientific and societal questions, and to build the tools and models needed to help people understand and adapt to the changes.

"So much of our improved understanding about global environmental changes is driven by varied and valuable sources of information that include networks of citizen-scientists," said John Wingfield, National Science Foundation’s assistant director for biological sciences. "The public at large has played an important role collecting observations and data for a hundred years and more. Knowledge and data gained from their work will continue to have a lasting effect on how we understand regularly recurring biological phenomena for hundreds of plant and animal species and contribute to the policy arena."

Gwen Lundburg in Seattle is one citizen-scientist who has contributed hundreds of entries into Nature’s Notebook. "Just noticing small changes like tiny purple lilac buds suddenly turning green has taught me to look more closely at my plants," Lundburg said. "I see things in my garden I never saw before."

With the help of citizen-scientist volunteers, working in concert with professionals, the USA-NPN, which was established in 2007, collects, stores and freely shares phenological data on more than 800 species of plants and animals. The Nature’s Notebook observing program has been in operation since 2009. The coordinating office of the organization is located at 1955 E. 6^th St., Tucson, Ariz., 85721. For more information, visit the USA National Phenology Network, or contact Jake Weltzin at 520-626-3821 or jweltzin@usgs.gov.

Rise in Asian Tiger Shrimp Sightings Prompts Scientific Look at Invasion Concerns

OC_Web@usgs.gov (Office of Communications and Publishing) — Thu, 26 Apr 2012 11:00:00 EDT

Additional Contact: Keeley Belva, NOAA 301-713-3066 Keeley.Belva@noaa.gov

Content updated - 4/26/2012 6:48 pm

GAINESVILLE, Fla. – The recent rise in sightings of non-native Asian tiger shrimp off the U.S. Atlantic and Gulf of Mexico coasts has government scientists working to determine the cause of the increase and the possible consequences for native fish and seafood in those waters.

Researchers from the U.S. Geological Survey and National Oceanic and Atmospheric Administration are working with state agencies from North Carolina to Texas to look into how this transplanted species from Indo-Pacific, Asian and Australian waters reached U.S. waters, and what the increase in sightings means for native species.

"We can confirm there was nearly a tenfold jump in reports of Asian tiger shrimp in 2011," explained Pam Fuller, the USGS biologist who runs the agency's Nonindigenous Aquatic Species database. "And they are probably even more prevalent than reports suggest, because the more fisherman and other locals become accustomed to seeing them, the less likely they are to report them."

NOAA scientists are launching a research effort to understand more about the biology of these shrimp and how they may affect the ecology of native fisheries and coastal ecosystems. As with all non-native species, there are concerns over the potential for novel avenues of disease transmission and competition with native shrimp stocks, especially given the high growth rates and spawning rates compared with other species.

"The Asian tiger shrimp represents yet another potential marine invader capable of altering fragile marine ecosystems," said NOAA marine ecologist James Morris. "Our efforts will include assessments of the biology and ecology of this non-native species and attempts to predict impacts to economically and ecologically important species of the Atlantic and Gulf of Mexico."

The cause of the rapid increase in sightings remains uncertain, Fuller added. The non-native shrimp species may have escaped from aquaculture facilities, although there are no longer any known Asian tiger shrimp farms presently in operation in the United States. It may have been transported in ballast water from ships or possibly arrived on ocean currents from wild populations in the Caribbean or other locations.

Fuller's team at USGS has been tracking reports of Asian tiger shrimp since they first came to the attention of marine scientists and resource managers in 1988, when nearly 300 of them were collected off the coasts of South Carolina, Georgia and Florida within three months. Scientists tracked the cause back to an isolated incident that accidentally caused an estimated 2,000 animals to be released from an aquaculture facility operating at that time in South Carolina.

It was not until 18 years later that reports of the non-native shrimp resurfaced. In 2006, a commercial shrimp fisherman caught a single adult male in Mississippi Sound near Dauphin Island, Ala. Within months, additional specimens were noted in North Carolina’s Pamlico Sound, Louisiana’s Vermilion Bay and other parts of Florida and the Carolinas. The species was later reported off the coasts of Georgia, Mississippi and Texas in 2008, 2009 and 2011, respectively.

Scientists have not yet officially deemed the Asian tiger shrimp "established" in U.S. waters, and no one is certain what triggered the recent round of sightings. With so many alternative theories about where these shrimp are coming from and only a handful of juveniles reported, it is hard for scientists to conclude whether they are breeding or simply being carried in by currents.

To look for answers, USGS and NOAA scientists are examining shrimp collected from the Gulf and Atlantic coasts to look for subtle differences in their DNA, information that could offer valuable clues to their origins. This is the first look at the genetics of wild caught Asian tiger shrimp populations found in this part of the U.S., and may shed light on whether there are multiple sources.

"We're going to start by searching for subtle differences in the DNA of Asian tiger shrimp found here – outside their native range –to see if we can learn more about how they got here," said USGS geneticist Margaret Hunter, "If we find differences, the next step will be to fine-tune the analysis to determine whether they are breeding here, have multiple populations, or are carried in from outside areas."

Anyone who sees one or more shrimp suspected to be an Asian tiger shrimp is asked to note the location and report the sighting to the USGS NAS database. If possible, freeze a specimen to help confirm the identity and contribute to a tissue repository maintained by NOAA.

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NOAA Center for Coastal Fisheries and Habitat Research Invasive Species

Satellite Tracking Reveals Sea Turtle Feeding Hotspots

OC_Web@usgs.gov (Office of Communications and Publishing) — Wed, 1 Feb 2012 15:00:00 EDT

Study Offers Clues to Loggerheads' Elusive Habits at Sea

GAINESVILLE, Fla. – Satellite tracking of threatened loggerhead sea turtles has revealed two previously unknown feeding ‘hotspots’ in the Gulf of Mexico that are providing important habitat for at least three separate populations of the turtles, according to a study published recently in the journal Biological Conservation.

The two sites, located in the open waters off the coast of Southwest Florida and the northern tip of the Yucatan Peninsula, were found by a team of scientists when they compiled and analyzed loggerhead tracking data.

The researchers' goal was to synthesize tracking data from three genetically distinct loggerhead populations to learn more about how they use the Gulf of Mexico. By identifying the specific location of regularly used habitat, the results provide invaluable information for marine planning and management for this species, whose populations in the Gulf of Mexico are well below historic levels and in recent years have continued to decline drastically in some areas.

The maritime feeding grounds also hold the first clues about how loggerhead sea turtles spend time at sea – which is, in essence, most of their lives.

"Up until now, management actions that affect loggerheads have often focused on their limited time at nesting beaches, or on fisheries regulations," said Kristen Hart, Ph.D., the U.S. Geological Survey research ecologist who led the synthesis. "Our findings open up important new options for marine habitat conservation, and provide valuable geographic data that can be used to strategically locate marine reserves based on the best available science, as called for in the new National Ocean Policy."

"The use of satellite tags for tracking marine animals has opened our eyes to the secret lives of some of nature's most elusive creatures," said USGS director Marcia McNutt, "At first a scientific tool to understand the life cycle of animals, such as white sharks and leatherback turtles, who rarely come into contact with humans, these tags may now be the main hope for understanding what we can do, or what we should stop doing, in order to bring them back from the road to extinction."

Researchers intercepted female loggerheads after their nesting forays to beaches and outfitted them with satellite tags at study sites in the Florida Panhandle, Casey Key in southwest Florida, and Dry Tortugas National Park. They then tracked the females’ migrations and used a new method to determine precisely when they had arrived at "hotspot" foraging areas, in two geographically different locations.

Seven female turtles migrated to foraging sites off Southwest Florida, while the other three took up residence at foraging sites at the Yucatan site. Once the researchers applied the new method for synthesizing their satellite-tracking data, it became clear that these loggerhead turtles from all three populations consistently converged around two common sites. This confirmed a hunch that the researchers had developed after years of tracking turtles.

At both of the feeding hotspots, turtles selected individual sites where they foraged in shallow or nearshore waters less than fifty meters deep. Turtles appeared to prefer their own distinct territories, where they tended to remain resident. This suggests that it may be possible to accurately predict where sea turtles will feed, information that will prove vital for managers looking to focus conservation efforts on prime foraging habitat.

Researchers don't yet know what attracts loggerheads from around the Gulf to these specific feeding areas, although generally, loggerheads forage on the bottom of the sea floor for crustaceans such as crabs, lobsters, clams or conchs.

"The logical next step is to investigate what makes these particular sites 'prime' foraging grounds by mapping and sampling the habitat types found on the sea floor," explained Hart. "It would also be useful to tag loggerheads at these foraging sites to confirm how long they reside in these areas, or alternatively to see where they go next."

Irrigation Causing Declines in the High Plains Aquifer

OC_Web@usgs.gov (Office of Communications and Publishing) — Wed, 1 Feb 2012 14:15:40 EDT

Groundwater withdrawals for crop irrigation have increased to over 16 million acre-feet per year in the High Plains Aquifer, according to a recent U.S. Geological Survey study.

The USGS study shows that recharge, or the amount of water entering the aquifer, is less than the amount of groundwater being withdrawn, causing groundwater losses in this already diminished natural resource. Crop irrigation is the largest use of groundwater in the aquifer, and, over the past 60 years, has caused severe water-level declines of up to 100 feet in some areas. The new USGS findings address concerns about the long-term sustainability of the aquifer.

"The High Plains Aquifer is Nature's nearly perfect water storage system: self-recharging, safe from natural disasters, readily accessed over a broad area, and with copious capacity," said USGS Director Marcia McNutt. "And yet in less than 100 years we are seriously depleting what took Nature more than 10,000 years to fill."

The High Plains aquifer underlies about 175,000 square miles in parts of eight states – Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming – and is a major source of groundwater irrigation in the region. The High Plains region supplies approximately one-fourth of the nation’s agricultural production.

"Because groundwater losses are greater than recharge, water levels in many parts of the aquifer are currently declining," said Jennifer Stanton, USGS scientist and an author of the report. "Such information can inform groundwater management decisions made by state and local agencies."

The new USGS study also compares previously published data with new methods for estimating recharge and groundwater withdrawals and provides an assessment of the strengths and weaknesses of those methods.

This USGS report is part of a larger study to evaluate groundwater availability of the High Plains Aquifer. The study is being conducted through the USGS Groundwater Resources Program to assist state and local groundwater management agencies and to assess the status of groundwater resources from a national perspective.

Click here to access the full report on line.

Severe Declines in Everglades Mammals Linked to Pythons

OC_Web@usgs.gov (Office of Communications and Publishing) — Mon, 30 Jan 2012 14:52:18 EDT

Additional Partnerships:


State Museum of Pennsylvania	Denison University

Constrictor Snakes (B-roll): Video footage (B-roll) of Everglades National Park biologists hunting and capturing a Burmese Python in Florida.

Editors: For frequently asked questions about this study and Burmese pythons, please visit the Fort Collins Science Center, Giant Constrictor Snakes in Florida website.

HOMESTEAD, Fla. -- Precipitous declines in formerly common mammals in Everglades National Park have been linked to the presence of invasive Burmese pythons, according to a study published today in the Proceedings of the National Academy of Sciences.

The study, the first to document the ecological impacts of this invasive species, strongly supports that animal communities in this 1.5-million-acre park have been markedly altered by the introduction of pythons within 11 years of their establishment as an invasive species. Mid-sized mammals are the most dramatically affected.

Bobcats are one of the predators that may be negatively affected by pythons, which both compete with them for prey and prey on them. Photo copyrighted by Christopher Gillette, Florida International University. This photo may be used by media and others in association with the Burmese pythons and Everglades press release. (High resolution image)

Once-common opossums are now rarely seen in Everglades National Park, likely because of being preyed upon by Burmese pythons. Photo copyrighted by Christopher Gillette, Florida International University. This photo may be used by media and others in association with the Burmese pythons and Everglades press release. (High resolution image)

The most severe declines, including a nearly complete disappearance of raccoons, rabbits and opossums, have occurred in the remote southernmost regions of the park, where pythons have been established the longest. In this area, populations of raccoons dropped 99.3 percent, opossums 98.9 percent and bobcats 87.5 percent. Marsh and cottontail rabbits, as well as foxes, were not seen at all.

"Pythons are wreaking havoc on one of America's most beautiful, treasured and naturally bountiful ecosystems," said U.S. Geological Survey Director Marcia McNutt. "Right now, the only hope to halt further python invasion into new areas is swift, decisive and deliberate human action."

The researchers collected their information via repeated systematic night-time road surveys within the park, counting both live and road-killed animals. Over the period of the study, researchers traveled a total of nearly 39,000 miles from 2003 to 2011 and compared their findings with similar surveys conducted in 1996 and 1997 along the same roadways before pythons were recognized as established in Everglades National Park.

The scientists who authored the paper noted that the timing and geographic patterns of the documented mammal declines are consistent with the timing and geographic spread of pythons.

The authors also conducted surveys in ecologically similar areas north of the park where pythons have not yet been discovered. In those areas, mammal abundances were similar to those in the park before pythons proliferated. At sites where pythons have only recently been documented, however, mammal populations were reduced, though not to the dramatic extent observed within the park where pythons are well established.

"The magnitude of these declines underscores the apparent incredible density of pythons in Everglades National Park and justifies the argument for more intensive investigation into their ecological effects, as well as the development of effective control methods," said Michael Dorcas, lead author of the study, a professor at Davidson College in North Carolina, and author of the book Invasive Pythons in the United States. "Such severe declines in easily seen mammals bode poorly for the many species of conservation concern that are more difficult to sample but that may also be vulnerable to python predation."

The mammals that have declined most significantly have been regularly found in the stomachs of Burmese pythons removed from Everglades National Park and elsewhere in Florida. The authors noted that raccoons and opossums often forage for food near the water's edge, a habitat frequented by pythons in search of prey.

The authors suggested that one reason for such dramatic declines in such a short time is that these prey species are “naïve” – that is, they not used to being preyed upon by pythons since such large snakes have not existed in the eastern United States for millions of years. Burmese pythons over 16 feet long have been found in the Everglades. In addition, some of the declining species could be both victims of being eaten by pythons and of having to compete with pythons for food.

"It took 30 years for the brown treesnake to be implicated in the nearly complete disappearance of mammals and birds on Guam; it has apparently taken only 11 years since pythons were recognized as being established in the Everglades for researchers to implicate pythons in the same kind of severe mammal declines," said Robert Reed, a USGS scientist and co-author of the paper. "It is possible that other mammal species, including at-risk ones, have declined as well because of python predation, but at this time, the status of those species is unknown."

The scientists noted that in their native range in Asia, pythons have been documented to consume leopards. Consequently, even large animals, including top predators, are susceptible to python predation. For example, pythons have been documented consuming full-grown deer and alligators. Likewise, the authors state that birds, including highly secretive birds such as rails, make up about a fourth of the diet of Everglades pythons, and declines in these species could be occurring without managers realizing it.

"Our research adds to the increasing evidence that predators, whether native or exotic, exert major influence on the structure of animal communities," said John Willson, a study co-author, a research scientist at Virginia Tech University and author of the book Invasive Pythons in the United States. "The effects of declining mammal populations on the overall Everglades ecosystem, which extends well beyond the national park boundaries, are likely profound, but are probably complex and difficult to predict. Studies examining such effects are sorely needed to more fully understand the impacts pythons are having on one of our most unique and valued national parks."

The authors found little support for alternative explanations for the mammal declines, such as disease or changes in habitat structure or water management regimes.

"This severe decline in mammals is of significant concern to the overall health of the Park's large and complex ecosystem," said Everglades National Park superintendent Dan Kimball. "We will continue to enhance our efforts to control and manage the non-native python and to better understand the impacts on the Park. No incidents involving visitor safety and pythons have occurred in the Park. Encounters with pythons are very rare; that said visitors should be vigilant and report all python sightings to park rangers," Kimball said.

On Jan. 23, 2012, the U.S. Fish and Wildlife Service published a rule in the Federal Register that will ban the importation and interstate transportation of four non-native constrictor snakes (Burmese python, northern and southern African pythons, and the yellow anaconda) that threaten the Everglades and other sensitive ecosystems. These snakes are being listed as injurious species under the Lacey Act. In addition, the FWS will continue to consider listing as injurious five other species of nonnative snakes: the reticulated python, boa constrictor, DeSchauensee’s anaconda, green anaconda and Beni anaconda.

The paper, Severe mammal declines coincide with proliferation of invasive Burmese pythons in Everglades National Park, was published online on Jan. 30, 2012, in the Proceedings of the National Academy of Sciences. The authors are Michael E. Dorcas, Davidson College; John D. Willson, Virginia Tech University; Robert N. Reed, USGS; Ray W. Snow, NPS; Michael R. Rochford, University of Florida; Melissa A. Miller, Auburn University; Walter E. Meshaka, Jr., State Museum of Pennsylvania; Paul T. Andreadis, Denison University; Frank J. Mazzotti, University of Florida; Christina M. Romagosa, Auburn University; and Kristen M. Hart, USGS.

USGS Announces Mineral Research Grants for 2012

OC_Web@usgs.gov (Office of Communications and Publishing) — Tue, 24 Jan 2012 13:54:41 EDT

New research on mineral resources important to our economy, national security, and land-use decisions has been funded by more than $260,000 in grants from the U.S. Geological Survey.

Recipients of the 2012 USGS Mineral Resources External Research Program (MRERP) grants will study rare earth elements (REE), niobium, and tellurium. The principal investigators and a brief description of each of the successful proposals are provided below.

"Although the US is currently dependent on foreign imports for our supply of rare earths and other critical elements that are essential for the high tech industry, our nation is actually rich in deposits of these valuable minerals," explained USGS Director Marcia McNutt. "The Mineral Research Grants help provide the basic research foundation to better develop our domestic resources and thus become less dependent on foreign imports."

Rare Earth Elements (REE) in Metamorphic Rocks of California
The University of California, Santa Barbara will focus on determining the origin of REE-bearing phosphate minerals in metamorphic rocks of the Music Valley region of California. This research is expected to provide a better understanding of how these phosphate minerals originally formed and provide insight on new geologic environments to target for REE exploration. The work is expected to help formulate better genetic models for REE-bearing mineral deposits and will decrease uncertainty in future assessments for these deposit types. The lead UC Santa Barbara scientist for this research is John Cottle.

The Rare Earth Element (REE) Potential of Igneous Rocks in Southern New Mexico
The New Mexico Bureau of Geology and Mineral Resources and the New Mexico Institute of Mining and Technology will conduct detailed mapping and geochemical studies in southern New Mexico to evaluate the potential for undiscovered thorium-REE-uranium vein deposits in the Caballo and Burro Mountains. The collection of new field data and laboratory analyses will help to fully assess the REE mineral resource potential of the rocks and associated veins in the region. The principal scientists on this research for the New Mexico Bureau of Geology and Mineral Resources, and the New Mexico Institute of Mining and Technology will be Virginia McLemore and Nelia Dunbar.

A Buried Rare Earth Element (REE ) and Niobium Deposit in Southeast Nebraska
The University of Colorado and the University of Nebraska-Lincoln will conduct a collaborative research project to examine the age and origin of the REE resources of the Elk Creek deposit in southeastern Nebraska by investigating previously collected drilling core. The Elk Creek REE deposit is found in a rare carbonate-rich igneous rock known as carbonatite. In addition to REEs, the Elk Creek carbonatite may comprise the largest niobium resource in the United States. Niobium is primarily used as an alloying element in steels and superalloys, such as materials used in high performance aircraft. This research is expected to yield data and information that will advance exploration and assessment models for similar REE deposits. The principal scientists for this research will be Lang Farmer of the University of Colorado and Matt Joeckel and Richard Kettler of the University of Nebraska-Lincoln.

Understanding How Rare Earth Elements (REE) Migrate in the Weathering Environment
The University of Texas at El Paso will investigate the distribution of REE in shales of different climatic zones and characterize the chemical controls on the release and transport of REE during the weathering process. This work is expected to help evaluate the fate and transport of REEs during the weathering of continental shale and advance our understanding of the formation of REE-bearing sediments in oceans and rivers, as potential new REE resources to explore and assess. The principal scientists on this research for the University of Texas at El Paso will be Lixin Jin and Lin Ma.

Understanding Tellurium (Te) as a Critical Mineral Commodity
Iowa State University will conduct detailed laboratory analysis to improve our understanding on the formation of tellurium-bearing minerals, evaluate the effectiveness of current tellurium extraction procedures, and determine the weathering pattern of tellurium-bearing mineral phases, to help assess mineral environmental impact of tellurium resource development. Tellurium is a rare metal most often used in steel alloys, as well as cadmium-telluride solar cells. This research is expected to advance our understanding of tellurium-bearing mineral deposits and provide more robust genetic and mineral environmental models for the assessment of undiscovered tellurium-bearing resources. The principal scientist on this research for Iowa State University is Paul Spry.

The MRERP invited research proposals that will expand its efforts in critical minerals research on commodities that are of increasing importance to economic and national security and may be subject to disruption in supply. Proposals were accepted from academia, State agencies, industry, or other private sector organizations and scientists. For more information about the USGS Mineral Resources External Research Program, visit our website.

Interior Releases First-of-its-Kind Regional Study as Part of National Assessment of Carbon Storage in U.S. Ecosystems

OC_Web@usgs.gov (Office of Communications and Publishing) — Mon, 5 Dec 2011 18:39:22 EDT

WASHINGTON, D.C. -- The Department of the Interior today released the first in a series of regional studies measuring the amount of carbon stored in U.S. ecosystems. Published by Interior's U.S. Geological Survey (USGS), the study examines the current and projected future carbon storage in the Great Plains region, as part of a nation-wide assessment.

Interior Releases First-of-its-Kind Regional Study as Part of National Assessment of Carbon Storage in U.S. Ecosystems

New Map of Big Bend National Park Bridges Past and Present Along the Texas/Mexico Border

OC_Web@usgs.gov (Office of Communications and Publishing) — Wed, 21 Sep 2011 17:25:51 EDT

More than 40 years ago, release of the original geologic map of Big Bend National Park drew nature enthusiasts, scientists, historians and adventurers to this diverse and desolate terrain along the Texas/Mexico border. Fast-forward to present day, and an updated U.S. Geological Survey map of Big Bend National Park provides a modern, digital picture of the 8^th largest park in the contiguous United States.

The "Geologic map of Big Bend National Park, Texas", may be found at online, and printed copies will be available for purchase through the USGS map store.

Big Bend National Park serves more than 350,000 visitors each year, and is renowned for its spectacular geology and protected Chihuahuan desert ecosystems. Intersected by the Rio Grande River, archaeologists have discovered artifacts estimated to be 9,000 years old, and historic buildings and other notable cultural resources offer a unique glimpse of life along the international border in the 19^th century.

The USGS map highlights greatly improved geology of the young sediments of the1252 square-mile park and updates its volcanic history. The map also shows the geology of the recently acquired Harte Ranch section in the northern part of the park.

"The National Park Service is pleased to receive this updated version," said Superintendent William Wellman. "Research techniques and theories have advanced greatly in the past 50 years, and the new map presents the updated information in a more detailed, modern format that can be used for scientific analysis for natural resource and ecosystem management. Geology has a profound influence on other park resources, and the information in this map will be used by park managers and researchers to help understand topics such as soils, plant communities, springs, ground water, and human history in the area."

Production of the map was a cooperative effort involving USGS, NPS, university professors and students, and Texas Bureau of Economic Geology.

Magnitude 5.3 Earthquake Rattles Southern Colorado

OC_Web@usgs.gov (Office of Communications and Publishing) — Tue, 23 Aug 2011 12:28:23 EDT

A magnitude-5.3 earthquake rattled southern Colorado Monday, August 22, at 11:46PM MDT, causing strong shaking, but minor damage, and was felt throughout the state of Colorado and neighboring states. The USGS Prompt Assessment of Global Earthquakes for Response (PAGER) system issued a Green Alert, indicating a low probability for fatalities or significant economic losses.

The earthquake occurred approximately nine miles southwest of Trinidad, Colo.

This was the largest earthquake in Colorado since a M5.3 in August, 1967 at Rocky Mountain Arsenal. The largest earthquake in Colorado history was Nov 7th, 1882, near Rocky Mountain National Park; estimates vary but it was about a Magnitude 6.5.

Yesterday's M5.3 had three detected foreshocks (M4.6, 3.0 and 2.9), and there have been many recorded aftershocks.

Citizens who felt the earthquake can go online and report their observations on the USGS Did You Feel It? website. Over 1,000 reports of felt shaking have already been received from more than 200 zip codes in six states.

Earthquakes cannot be predicted. This area in Colorado has a history of earthquakes, notably a swarm that occurred in 2001, with earthquake magnitudes between M2.9 and 4.6. A USGS report on those earthquakes is available at the USGS Earthquake Hazards Program website.

For more information on earthquake and other hazards, please visit the USGS Natural Hazards website. The USGS operates a 24/7 National Earthquake Information Center in Golden, Colo., that can be reached for more information at (303) 273-8500.

Biofuels, Beetles, and Buffelgrass: A Changing World Takes Root in Austin

OC_Web@usgs.gov (Office of Communications and Publishing) — Fri, 5 Aug 2011 15:26:09 EDT

Media may arrange interviews by contacting Marisa Lubeck via the information provided above.

From northward-creeping invasive vines to man-made mangroves, U.S. Geological Survey ecosystem research will be presented at an Austin meeting next week.

USGS scientists will join ecologists from around the world at the annual Ecological Society of America (ESA) meeting from August 7 - 12 at the Austin Convention Center in Austin, Tex. This year, USGS scientists will focus on topics such as invasive species and habitat changes.

This USGS “tip sheet” highlights some of the newest, most exciting USGS presentations open to media at the ESA meeting. Information on news media attendance can be accessed on the 2011 ESA conference website.

Anne Kinsinger, USGS Associate Director for Ecosystems, will be available to discuss these and other USGS ecological research projects at the USGS Meet and Greet on Tuesday, August 9, from 6:30 – 8 p.m. in the Austin Convention Center Ballroom E.

Media are also encouraged to visit the USGS booth in the Austin Convention Center Exhibition Hall 4.

As the Mouse Goes: Where Do Joshua Tree Seeds End Up?
Tuesday, August 9, Exhibit Hall 3

It has adorned rock album covers and decorated movie backdrops, but the iconic Joshua tree (Yucca brevifolia) is a difficult species to manage and conserve because conditions favorable to its regeneration and spread are very infrequent. This poster offers a primer on the many odds Joshua tree seeds must face in order persist and successfully grow into a seedling. By simulating rodent seed caches at Mojave Desert field sites, USGS ecologists investigated emergence and survival of Joshua Tree seeds in relation to microclimate, season of planting, and predation on seedling emergence and survival. This poster is titled Germination and establishment of the Joshua tree (Yucca brevifolia) in the northeast Mojave Desert: Implications for management of an iconic species.

A Plan for Managing Species Invasions
Tuesday, August 9, 8:40 a.m., Room 12A

Preventing invasive species introductions is optimal for controlling their spread, but, should an invasion still occur, early detection and rapid response is an effective course of action. If invasive species become established, then the plan calls for control and management of further spread and for the restoration of high-valued ecosystems. Dr. David Pyke will present a review of these defenses in combating introduction and spread of invasive species in grasslands, shrublands, and savannas. He will discuss whether adaptation or coexistence may be the ultimate fate with certain problematic species, and the gap in research on management for coexistence. This review is titled Managing species invasions: eradication, patience, or adaptation?.

Endangered Salamanders Further Threatened by Climate Change
Tuesday, August 9, 3:20 p.m., Room 8

Limited to three mountaintops, the Shenandoah salamander is already endangered – and this vulnerable species is likely to suffer even greater population loss to climate change. According to a USGS study that used models to predict possible futures for the salamander, climate change will further threaten the Shenandoah salamander in the years to come. Predicted dramatic differences in high elevation habitats because of climate change are risky to any species reliant on the high elevation communities for survival. Decision makers at Shenandoah National Park will be able to use the study to guide decisions to restore salamander population growth rates, and the study has implications for managing and mitigating the effects of climate change on the high elevation communities where the salamanders (a sentinel species) live. This study is titled Managing for climate change in the mountains, the Shenandoah salamander.

Destroying Fields of Gold: Restoring Mojave Desert Shrubland
Tuesday, August 9, 3:20 p.m., Ballroom F

The golden grasslands seen in many Mojave Desert landscapes today are unnatural, the result of massive swaths of invasive, nonnative brome grasses which greatly heighten wildfire risks in the Mojave and pose a threat to many native plant and animal species. However, USGS ecologists found that a regimen of invasive suppression, native plant seeding, and management of soil-seed reserves is a promising strategy for helping burned desert habitats recover. The USGS worked with resource managers in Arizona to test invasive grass removal methods to determine the successes of using herbicide application to impede invasive grass growth, and determining negative impacts to native plants dispersed in the same area. This talk is titled The role of a pre-emergent herbicide to suppress non-native annuals and facilitate the recovery of a burned Mojave Desert shrubland.

Mountain Pine Beetle Alters Carbon Cycling and Species Composition
Tuesday, August 9, 4:30 p.m., Exhibit Hall 3, Board 157

The outbreak of the mountain pine beetle in the Rocky Mountain lodgepole pine could cause short and long term changes to carbon cycling and species composition, according to a recent USGS study. Forest ecosystems as a whole hold 60 percent of all terrestrial carbon globally, acting as a sink for atmospheric carbon. Landscape level disturbances, such as the mountain pine beetle outbreak may alter the amount of carbon that can be sequestered over time. The simulation estimated that after 40 years, the carbon distribution would go back to the levels standard before the beetle outbreak, but that the composition and structure of the vegetation were changed significantly for the long haul. Large insect disturbances may introduce greater uncertainty in evaluating and managing forested ecosystems and understanding how they offset greenhouse gas emissions. This study is titled Changes in forest vegetation and carbon storage following mountain pine beetle disturbance in the Southern Rocky Mountains.

Biofuel Production in the Southwestern U.S. Could be a Hot Option
Wednesday, August 10, 1:30 p.m., Room 18D

In the southwestern U.S., lots of light and land are conducive to the production of biofuels like switchgrass and canola. While most of the raw crop that is turned into biofuel in the U.S. is grown on productive agricultural lands, thus sparking fears about food security, this USGS study found that the marginal lands unsuited for agriculture could support some of the crops necessary for biofuel. These biofuels are accustomed to a hot and dry climate, and may have simultaneous benefits for restoration or fire prevention. While the impacts of biofuel production on southwest ecosystems aren’t fully understood, many states have set mandated alternative energy benchmarks that they must meet within the upcoming decades. This study is titled Biofuel production potential in the southwestern U.S.

Battling Buffelgrass
Thursday, August 11, Exhibit Hall 3

Buffelgrass (Pennisetum ciliare), an aggressive, invasive plant spreading throughout the southwestern U.S., creates a fire risk that threatens the native ecosystems and human properties that are poorly adapted to it. However, USGS research suggests that a large upfront investment in the control of buffelgrass could substantially reduce spread and overall management costs in the long run. Spatial simulations showed that without treatment, areas that started with as few as 80 hectares of buffelgrass could spread to more than 6,000 hectares by the year 2060 if left unchecked. In contrast, applying unlimited resources could limit 2060 infestation levels to a mere 50 hectares. The key is to identify the current presence and distribution (inventory) of this grass so that treatments can be applied. USGS scientists and collaborators created a model for the wildland-urban interface north of Tucson, Ariz., to address the level and allocation of resources that would be required to stem its spread. This study is titled A decision support model for buffelgrass management in southern Arizona.

Invasive Kudzu Vine Creeping toward Canada?
Thursday, August 11, 8:00 a.m., Ballroom C

Invasive species are spreading into new territories at unprecedented rates, with the highly aggressive vine kudzu (Pueraria montana) being a prime example. But could kudzu, associated with southeastern U.S. environments, reach Canada? It’s possible. According to USGS models, kudzu could increase its distribution with climate change, particularly in the Northeastern U.S. and potentially into vulnerable locations in Canada. USGS scientists used existing global climate datasets to project potential climate change into the future and associated kudzu proliferation in the U.S. After creating habitat suitability maps for kudzu under current climatic conditions, investigators projected these models geographically into Canada and up to 30 years into the future using potential average conditions. Managers can use this information to create watch lists of invaders at the leading edges of invasion to prevent them from spreading across borders. This study is titled Predicting kudzu in the US and Canada in response to climate change and other factors.

Removal of Invasive Tamarisks Affects Native Grasses, Birds
Friday, August 12, 9:00 a.m., Room 16A

Saltcedar or tamarisk (Tamarix spp.), an invasive shrub or small tree that was deliberately introduced to America in the late 1800's, has since altered native ecosystems in the western U.S. This USGS study considered the short-term response of vegetation, birds, and associated habitats to saltcedar removal at sites along the Virgin River in Nevada and Arizona, and found that sites without saltcedar removal had higher densities of native grasses, higher abundance of birds (including seven species of concern), and a greater availability of bird habitat when compared against sites with saltcedar removal. The findings underscore the need for careful consideration of short-term ecosystem responses for invasive species removal operations. This study is titled Plant and bird community response to saltcedar removal along the Virgin River: Considerations for riparian restoration.

Created Mangroves Second to Nature?
Friday, August 12, 10:10 a.m., Room 16A

Exactly how similar are natural and created mangroves? Created coastal mangroves, used more and more to mitigate the loss of declining natural mangroves, do have significant differences from their natural counterparts: A USGS and U.S. Environmental Protection Agency study of 18 sites in the Tampa Bay region of Florida found that natural sites had mangroves that were larger and denser with different soil properties than the created mangrove sites. However, older created mangrove sites were beginning to develop the soil quality and carbon-storing potential of the natural mangrove sites, indicating that some of the shortcomings of the created mangroves could lessen over time. While mangroves can stabilize coastal lands and store large amounts of carbon, they are also sheltered nursery areas for marine life and play a vital role in the marine food web. This study is titled Ecosystem development after mangrove creation: Plant-soil change across a twenty-year chronosequence.

Bringing the Cows Home: Long-term ecosystem responses to livestock removal in the Mojave Desert
Friday, August 12, 10:50 a.m., Room 16A

Heavy livestock grazing, common across the arid western U.S., can degrade ecosystems and habitats, affecting species in the Mojave Desert such as the federally threatened desert tortoise (Gopherus agassizii). USGS research suggests that ecosystem recovery following livestock removal occurs very slowly: The effects of historic livestock grazing are still apparent for Mojave soils and native perennial vegetation seven years after livestock removal. USGS scientists investigated properties of soils and plant communities immediately following and seven years post-livestock removal in previously grazed desert scrub of the Mojave National Preserve. The results suggest that further active restoration efforts (beyond livestock removal) may be necessary to achieve ecosystem recovery. This study is titled Long-term ecosystem responses to livestock removal in the Mojave Desert.

Along the 100th Meridian

OC_Web@usgs.gov (Office of Communications and Publishing) — Wed, 6 Jul 2011 16:20:10 EDT

Historical Extremes in Water

Record flooding along the Souris River near Minot, N.D. and record drought at O.C. Fisher Lake near San Angelo, Texas have more than their contrasting water conditions in common.

These places, nearly 1,000 miles apart, are situated almost exactly north and south of each other near the100^thmeridian of longitude. On average they have similar amounts of precipitation. Minot typically receives 17.5 inches per year while San Angelo customarily tallies 22.5 inches annually.

"The upper Souris Basin has been quite moist since last fall," said Steve Robinson from the U.S. Geological Survey North Dakota Water Science Center. "An above normal winter snowpack in addition to much above normal precipitation in May and June led to the record flooding along the Souris River."

Meanwhile, Texas is experiencing near record drought conditions four states south of North Dakota. Jason Johnson of the National Weather Service in San Angelo said that this is the driest nine-month period in Texas since record collection began more than 100 years ago.

Cary Carman of the USGS office in San Angelo grew up in west Texas where many of his relatives still recall the historic drought of the 1950s. Carman said that although O.C. Fisher Lake has been dry before, he has not seen such parched conditions.

"It is a challenge to keep streamgaging instrumentation working properly because many streams and reservoirs are so low," said Carman.

In the late nineteenth century, the 100th meridian, one hundred degrees of longitude west of Greenwich, England, emerged as a widely-recognized line that represented the boundary in the central United States between the moist east and the arid west. In his 1878 "Report on the Lands of the Arid Region of the United States," John Wesley Powell, the second Director of the USGS, noted the boundary that has resonated to this day.

The 100^th meridian was not solely selected for its neat round number; it actually approximates the north-south line of twenty inches of annual average precipitation. When an area receives more than twenty inches of precipitation, irrigation is often not necessary. Thus, this line of longitude marks the approximate boundary between the non-irrigated east and the irrigation-needed west.

Log in to the USGS WaterWatch site to stay apprised of both floods and drought across the country. WaterWatch displays maps, graphs, and tables that describe real-time, recent, and past streamflow conditions for the United States. The real-time information generally is updated on an hourly basis.

Detailed statistics of the water extremes described here may be viewed online in real-time. Click here for Minot, N.D. and here for O.C. Fisher Lake, San Angelo, Texas.

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