Recovering Soil Fertility after Forest Fires plus 11 more
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- Recovering Soil Fertility after Forest Fires
- San Francisco Bay Area Groundwater: Some Chemicals Less Prevalent at High Concentrations than Statewide
- Tsunami Preparedness Week Observed in California
- Pika Populations Affected by Climate in the Great Basin
- USGS Cancels March Public Lecture in Menlo Park
- Media Advisory: Is "The Impossible" Possible in the Pacific Northwest? - Coastal Community Tsunami Hazards and Risk
- Madera County Groundwater Quality: Fumigants Found More Often at High Concentrations than in Other Areas of California
- Lake Mead Aquatic-Science Research Documents Substantial Improvements in Ecosystem
- Media Advisory: Exploring the Earth's Crust – Seismology Uncovers Hidden Secrets Beneath Our Feet
- California Desert Groundwater Quality: More Inorganic Elements than Statewide; Other Constituents Less
- Media Advisory: Colorful South Pacific Species – New Discoveries and Looming Threats
- Media Advisory: USGS Science at AGU
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Recovering Soil Fertility after Forest Fires Posted: 03 Apr 2013 11:00 AM PDT CORVALLIS, Ore.— New scientific findings published in Ecology reveal that interactions of climate, soils, shrubs, and a natural nitrogen fertilization process affect regrowth of forests following wildfire in southern Oregon and northern California. Managers can use this information to consider post-fire management practices, including fertilization and shrub-removal. Scientists studying forests that burned in 1987 discovered an interesting pattern in a natural fertilization process. The highest levels of natural nitrogen fertilization occurred at cool, dry sites where tree growth is slow and where nitrogen for growth is needed the least. In contrast, the lowest nitrogen additions occurred at warm, moist sites where tree growth and associated nitrogen needs are greatest. This counterintuitive result occurred because natural nitrogen fertilization by nitrogen-fixing shrubs was suppressed by competition with oaks, maples, and other vegetation where tree growth was greatest, in warm, moist sites. Nitrogen, an essential nutrient for tree growth, often is lost during a forest fire. An important way to recover forest fertility is an ecological process called biological nitrogen fixation. Some common shrubs, like Ceanothus, form unique relationships with bacteria and convert inert nitrogen gas from the air into forms of nitrogen in the soil that the trees can use for growth. Free-living soil bacteria also fix nitrogen. This natural process is the main source of nitrogen fertility in forests. The scientists found that the rate at which Ceanothus shrubs added nitrogen to the system could be suppressed as tree biomass increased. Even though warm, wet sites stimulated the growth of nitrogen-fixing shrubs, these conditions stimulated the growth of other plants even more. Eventually, these changes limited the recovery of nitrogen fertility in the most productive sites. According to Stephanie Yelenik, the lead author of the study, nitrogen additions by Ceanothus shrubs and by free-living soil bacteria provided an average of 7.5 pounds of nitrogen per acre per year. Over the 22 years following the major fire when the forest’s vegetation and nitrogen burned, this added up to about 165 pounds of nitrogen per acre. Although probably insufficient to fully replace wildfire nitrogen losses on the study sites, these contributions were substantial. Yelenik was affiliated with Oregon State University at the time of the study. "There are important related results. Biological nitrogen fixation involving Ceanothus shrubs was up to 90 times greater than contributions from free-living soil microorganisms," said USGS scientist Steve Perakis, who participated in the study. "The contribution from Ceanothus would be even greater if other plants didn't compete so strongly. So ultimately competition among different plant species governed nitrogen input in the forests studied." "The loss of nitrogen to wildfire has always been of concern to managers; however, the enormity of this loss only recently has been quantified," said Tom Sensenig, a U.S. Forest Service ecologist. "This study not only informs managers about the importance of shrubs for restoring nitrogen, but identifies the dynamics among species and the specific processes influencing nitrogen fixation and recovery across differing sites. Principally, this new information will help in developing post-fire management options and plans for specific forest types in this region. For example, on drier lower-quality sites, Ceanothus, the most prevalent nitrogen-fixing shrub identified, could be retained to the greatest extent possible by only treating the minimal vegetation necessary to assure seedling survival. On wetter, higher-productivity sites, treating more competitive species at a higher intensity may be more effective for maximizing nitrogen recovery, while benefiting seedling survival as well." According to Yelenik, without additional fire or other forms of disturbance, Ceanothus largely disappears from productive sites in about 30 years as the tree canopy shades out the understory vegetation. Because Ceanothus is the major player in biological nitrogen fixation, from then on, nitrogen levels may remain consistently low in sites that have the necessary temperature and moisture conditions to promote rapid tree growth. On these sites, there may be opportunities to conduct vegetation management or to allow low-severity fires to burn as a way of encouraging the presence of nitrogen-fixing shrubs in the forest understory. The study sites were located in forested mountains of the Klamath Region. This region is prone to wildfires, and the frequency and severity of the fires shape vegetation patterns. The study occurred 20 to 22 years after fire in sites that were salvage logged in the first 2 to 3 years after fire and then planted with conifer trees. Perakis believes the results are best applied to this region, but the interactions between climate, soils, shrubs, and natural nitrogen fertilization merit study elsewhere to see if similar constraints to nitrogen fixation occur in other forests recovering from fire. The publication is Yelenik, S.G., S.S. Perakis, and D.E.Hibbs. 2013. Regional constraints to biological nitrogen fixation in post-fire forest communities. Ecology. |
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Posted: 29 Mar 2013 09:00 AM PDT SAN DIEGO, Calif. — Barium and nitrate were detected at high concentrations in 5 percent of untreated groundwater used for public-water supply in the San Francisco Bay region, while human-made organic chemical constituents were found at high concentrations in less than 1 percent. These detections are less prevalent than elsewhere in California, according to an ongoing U.S. Geological Survey study of the state's groundwater quality. This study's findings are significant because elsewhere in California, high concentrations of inorganic elements generally are found in 10 to 25 percent of the groundwater used for public supply, nitrate in 1 to 8 percent, and human-made organic chemical constituents in up to 2 percent. "High" concentrations are defined as above the Environmental Protection Agency's, or California Department of Public Health's established Maximum Contaminant Levels, or above other non-regulatory health-based levels for chemicals without MCLs. The USGS did not analyze treated tap water delivered to consumers. Groundwater is typically treated by water distributors prior to delivering it to customers to ensure compliance with water quality standards for human health. "Nitrate has the greatest potential to impact groundwater quality given its prevalence of 2 percent at high and 19 percent at moderate concentrations in the San Francisco Bay region, however, high concentrations of organic compounds and naturally occurring trace elements are less prevalent here than other study areas statewide." said Dr. Justin Kulongoski, a USGS chemist and co-author of the report prepared in collaboration with the California State Water Resources Control Board. The San Francisco Bay study was part of the Groundwater Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project, a statewide study designed to assess groundwater quality in aquifers that may be used for public water supply and to better understand the natural and human factors affecting groundwater quality. U.S. Geological Survey scientists analyze untreated groundwater from wells in the San Francisco Bay region in 2007, looking for as many as 287 chemical constituents. The San Francisco Bay study region includes the Marina, Lobos, Downtown, Islais Valley, South San Francisco, Visitacion Valley, Westside, and Santa Clara Valley groundwater basins in San Francisco, San Mateo, Santa Clara, Alameda, and Contra Costa counties. "The work done by the GAMA Priority Basin Project in the San Francisco Bay groundwater basins is important because we are providing, for the first time, a quantitative assessment of the extent to which deeper groundwater may have high concentrations of both natural and man-made constituents," said Dr. Miranda Fram, chief of the USGS GAMA program. "This information can be used by managers to insure that our drinking water supply remains safe." The volatile organic compounds (VOCs) tetrachloroethene (PCE) and methyl tert-butyl ether (MTBE) were detected at high concentrations in less than 1 percent of the San Francisco Bay aquifer system, which is similar to other areas of California. These VOCs are used for industrial purposes including cleaning during manufacturing and improving gasoline-combustion efficiency. High concentrations of barium were detected in about 3 percent of the aquifer system. Barium and other trace elements are naturally present in the minerals in rocks and soils and in the water that comes into contact with those materials. High concentrations of nitrate were detected in about 2 percent of the aquifer system, and moderate concentrations, found at greater than one-half of the MCL, in about 19 percent. Elevated concentrations of nitrate generally occur as a result of human activities, such as applying fertilizer to crops or landscaping. Septic systems, as well as livestock in concentrated numbers, also produce nitrogenous waste that can leach into groundwater. Total dissolved solids (TDS), a natural inorganic constituent that affects the aesthetic properties of water, such as taste, color, and odor, or may create scaling or staining, was detected at high concentrations in 7 percent of the primary aquifer system and at moderate concentrations in 37 percent. The USGS California Water Science Center is the technical lead for the GAMA Priority Basin Project. The USGS is monitoring and assessing water quality in 120 priority groundwater basins, and groundwater outside of basins, across California over a 10-year period. The main goals of the State Water Board’s GAMA Program are to improve comprehensive statewide groundwater monitoring and to increase the availability of groundwater-quality information to the public. The full report and the accompanying non-technical Fact Sheet are available online. |
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Tsunami Preparedness Week Observed in California Posted: 25 Mar 2013 10:30 AM PDT
SACRAMENTO, Calif. — Two years after the Tohoku earthquake and tsunami devastated Japan and caused millions of dollars in damage to California coastal communities, the state's Emergency Management Agency and the California Geological Survey continue to work with their local, state and federal partners to reduce the impacts of future tsunamis in California. During the week of March 24-30, Cal EMA and CGS will again join with the National Oceanic and Atmospheric Administration and their local and state partners to observe Tsunami Preparedness Week. Recent preparedness efforts have included testing the tsunami warning communications system, participation in table-top exercises and public education forums, and the development of brochures, videos and other materials for children, boaters and the general public. A new study published by the U.S. Geological Survey, "Community Exposure to Tsunami Hazards in California," provides first responders, emergency planners and other stakeholders, with valuable new information about the people who live in, work in, and visit tsunami hazard areas in 20 counties and 94 incorporated cities located along the state's coast. This information provides local planners with a new tool to help refine their tsunami outreach efforts, as well as emergency preparedness and response efforts during future exercises and emergencies. The USGS report builds upon tsunami inundation maps that were previously developed by Cal EMA, CGS and the University of Southern California depicting the maximum extent of tsunami inundation for all 20 coastal counties. "Even though California has the most communities designated by NOAA as 'TsunamiReady,' we are not resting on our laurels," said Cal EMA Secretary Mark Ghilarducci. "This new study by the USGS will help make California's coastal communities even better prepared by providing emergency planners, first responders and elected officials with data they can use to build on the information already provided by the tsunami inundation maps." "Having a better sense of the number and type of people that are in tsunami-prone areas of each coastal community allows emergency managers to develop tsunami outreach and preparedness strategies that are tailored to address local conditions and needs," said USGS geographer Nathan Wood, lead author of the new report. "Tsunami outreach and preparedness opportunities will vary if the at-risk population is a tight-knit community of retired residents, seasonal workers in a bustling port and harbor complex, or tourists on the beach. Although the tsunami hazards are similar, the vulnerability of each community to these hazards will vary depending on how they use tsunami-prone areas." "CGS values this study and its partnership with the USGS," said Dr. John Parrish, the State Geologist of California and head of CGS. "This product will greatly improve the generation of tsunami hazard products and the ability of state agencies to assist local communities prepare for future tsunamis events.” "Even though all levels of government continue to enhance our preparedness and response capabilities, individual preparedness remains the biggest weakness we face," said Ghilarducci. Ghilarducci noted that a 2008 study conducted by UCLA School of Public Health and Survey Research Center for the State of California indicated that only 40 percent of Californians had developed family disaster plan. Emergency officials and urged everyone who lives in, works in or visits California's coastal communities to observe Tsunami Preparedness Week by:
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Pika Populations Affected by Climate in the Great Basin Posted: 13 Mar 2013 09:38 AM PDT BOZEMAN, Mont. – Climate factors such as snowpack and precipitation are playing an increasingly important role in the abundance of American pikas in the Great Basin, according to a continuing ecological study by the U.S. Geological Survey, University of Montana and Montana State University. Pikas are diminutive herbivores that resemble hamsters and live exclusively in rocky slopes across many mountain ranges in the American West. This study contributes to a legacy of more than 100 years of pika studies in the Great Basin – the internally draining area between the Sierra Nevada and Rocky Mountains. In the Basin, researchers are recording pikas' shrinking distribution, and finding their population sizes increasingly responsive to climate change but difficult to predict. The size of pika populations did not correlate with the extent of habitat present in either the 1990s or 2000s, according to the researchers, who were revisiting sites where pikas were first recorded in historical surveys going back more than a century. Given how strongly pikas are tied to their rocky habitat, this current finding challenges the assumption that just because physically suitable habitat is present – even in remote, apparently relatively undisturbed locations – that pikas will continue to occupy those habitats. Researchers also investigated the potential impact of climate stress on pika density. The results suggested that climate change may be adding another filter for suitability of habitats. "Precipitation during June-September and amount of snowpack appeared to be the most powerful predictors of pika density in the 2000s," said USGS research ecologist Erik Beever, lead author of the study. "Precipitation appears to be important because it can influence the amount of food available for pikas in the summer, and an insulating snowpack can minimize exposure of pikas to extreme cold-stress," Beever said. Across the western United States, snow-water equivalents have been declining and temperatures have been rising since the 1930s. Perhaps the most surprising result was the direct relationship between population size and probability of future extinctions of local pika populations. "When we consider extinction risk, we intuitively think that smaller populations are at the highest risk," Beever said. "We looked at the record of extinctions up to 1999, and calculated the risk of future site-level extinction. We were surprised to find that sites with higher extinction risk in 1999 had larger populations in 2003-2008," he said. The authors suggest that this non-intuitive result may reflect changes in the rules governing abundance between the 1990s and 2000s surveys (perhaps ushered in by recent climate change), lags in response of abundance to extinction risk, or other mechanisms. Researchers revisited sites of historical (1898-1956) pika records and performed surveys of pika abundance from 1994 to 1999 and from 2003 to 2008 to understand the factors predicting pika population sizes. The study, "Understanding relationships among abundance, extinction and climate at ecoregional scales," to be published in the journal Ecology, is available online. |
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USGS Cancels March Public Lecture in Menlo Park Posted: 13 Mar 2013 09:00 AM PDT MENLO PARK, Calif. —The U.S. Geological Survey is cancelling its March 28th Evening Public Lecture "Preparing for California Climate Change," due to travel restrictions the agency has implemented because of the federal budget sequestration. The scheduled speaker had planned to travel to Menlo Park from La Jolla, Calif. to meet with USGS Menlo Park staff and give the presentation, but the new restrictions prohibit all but mission-critical travel. In addition to the travel restrictions due to the sequestration, the USGS has implemented a hiring freeze; eliminated or significantly reduced participation in all scientific conferences; cancelled all non-mandatory, non-mission critical training; directed a review of contracts and grants to determine which should be delayed, re-scoped, or terminated; and may have to furlough employees for an undetermined amount of time. Established in 1990, the USGS Evening Public Lecture Series in Menlo Park is usually held on the last Thursday of every month, and provides an opportunity for the public to meet scientists and learn first hand about USGS research and how it affects our daily lives. The lecture series provides the public with relevant, accurate, but non-technical scientific information to create a better understanding of the importance and value of "Science for a Changing World." The last time a lecture in the Menlo Park USGS series was cancelled was September 2001, immediately after the terrorist attacks. Prior to that, the USGS canceled a lecture in November 1995 when the federal government shut down and employees were furloughed. The USGS will re-evaluate the future of its public lecture series in Menlo Park as the budget picture becomes more clear. Please continue to check the USGS Evening Public Lecture website for updated information about the status of future lectures. |
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Posted: 25 Feb 2013 08:00 AM PST Free USGS Public Lecture February 28MENLO PARK, Calif. — The movie "The Impossible" graphically depicts destruction caused by the 2004 Indian Ocean tsunami which resulted in catastrophic loss of life and property – are similar, equally destructive events likely to occur in the Pacific Northwest? USGS Geographer Nathan Wood will explain which coastal communities are the greatest risk, and what can be done now to prepare for future Cascadia tsunamis. He will also explain how he provides disaster planning officials with needed information to develop effective emergency response plans.
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Posted: 11 Feb 2013 08:00 AM PST SACRAMENTO, Calif. — Arsenic, uranium, fumigants and nitrate were detected at high concentrations in untreated groundwater at depths in the aquifer system typically used for public water supply in the Madera County region of California’s San Joaquin Valley. High concentrations of fumigants were detected in about 10 percent of the aquifer system. High concentrations of fumigants have been found in other parts of the San Joaquin Valley, in addition to the Madera County region; however, in other areas of California, high concentrations of fumigants were found in less than 1 percent of the aquifer system used for public water supply. The Madera County study was part of a statewide study designed to assess groundwater quality in aquifers that may be used for public water supply and to better understand the natural and human factors affecting groundwater quality. U.S. Geological Survey scientists analyze untreated groundwater from wells, not tap water delivered to consumers. Groundwater is typically treated by water distributors prior to delivering it to customers to ensure compliance with the U.S. Environmental Protection Agency’s and the California Department of Public Health's water quality standards for human health. The Madera County region consists of the Madera and Chowchilla groundwater aquifer subbasins and also includes small parts of Fresno and Merced counties. "Over a 10-year period, the USGS is characterizing groundwater quality in 120 groundwater basins and other areas that supply about 95 percent of public groundwater supplies," explained USGS Director Marcia McNutt. "The new results for the Madera and Chowchilla subbasins show where, what, and how much contamination is in the groundwater, focusing attention on improving water quality where it is needed." "High" concentrations are defined as above the California Department of Public Health"s established Maximum Contaminant Levels (MCLs) or other health-based levels for chemical constituents or elements not having state-established MCLs. The fumigant detected at highest concentrations, DBCP, was used historically to control nematodes in vineyards and orchards, but has not been used in California since 1977. "The DBCP we detected is not new to the aquifer system. It has taken time for the DBCP to move from the land surface to the aquifer depths tapped by public supply wells," said Jennifer Shelton, a USGS hydrologist and author of the report prepared in collaboration with the California State Water Resources Control Board. High concentrations of uranium and arsenic, above the state's maximum contaminant levels, were detected in about 17 percent and 13 percent of the aquifer system respectively. Uranium and arsenic are naturally present in rocks and soils and in the water that comes in contact with those materials. High concentrations of arsenic in the Madera and Chowchilla aquifer system can be attributed to natural processes, whereas high concentrations of uranium are due to both natural processes and human activities. Nitrate was detected at high concentrations, above the MCL, in about 7 percent of the aquifer system, and at moderate concentrations in about 20 percent. High and moderate concentrations of nitrate generally occur as a result of human activities. Sources of nitrate include fertilizers applied to crops and landscaping, seepage from septic systems, and human and animal waste. "Local water distributors, and regional, state, and federal agencies, as well as the USEPA, are aware of the presence of uranium, nitrate, arsenic and fumigants in groundwater in Madera, Merced, and Fresno counties, and are actively working to manage local groundwater resources," said Dr. Miranda Fram, chief of the USGS Groundwater Ambient Monitoring and Assessment Program. The USGS California Water Science Center is the technical lead for the State Water Resources Control Board GAMA Program’s Priority Basin Project. The USGS is monitoring and assessing water quality in 120 priority groundwater basins, and groundwater outside of basins, across California over a 10-year period. The main goals of the State Water Board’s GAMA Program are to improve comprehensive statewide groundwater monitoring and to increase the availability of groundwater-quality information to the public. The full report and the accompanying nontechnical Fact Sheet are available online. |
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Lake Mead Aquatic-Science Research Documents Substantial Improvements in Ecosystem Posted: 29 Jan 2013 01:41 PM PST Additional Partnerships: University of Nevada, Reno and University of Nevada, Las Vegas Additional Contacts: Dan Balduini, USFWS, 702-515-5480, daniel_balduini@xxxxxxx and Peter Soeth, Reclamation, 303-445-3615, psoeth@xxxxxxxx LAS VEGAS, Nev. — Lake Mead National Recreation Area's water quality is good, the sport fish populations are sufficient, and the lakes provide important habitat for an increasing number of birds. This positive trend is documented in a new report published today that leads to a better understanding of the natural resources of Lake Mead and Lake Mohave, and the issues that may affect natural resource management of Lake Mead NRA. "While the Lake Mead ecosystem is generally healthy and robust, the minor problems documented in the report are all being addressed by the appropriate agencies, and are showing substantial improvement since the mid 1990's," said U.S. Geological Survey hydrologist, Michael Rosen, the lead scientist for the report. "This is thanks to proactive enhancements to wastewater treatment facilities for the Las Vegas Metropolitan area, the installation of wetlands in Las Vegas Wash, and the treatment of legacy pollutants from industrial areas near Las Vegas Wash." Lake Mead provides significant benefits that have contributed to the modern development of the southwestern United States. The lake provides important aquatic habitat for a wide variety of wildlife including endangered species, and a diversity of world-class water-based recreational opportunities for more than 8 million visitors annually. It supplies critical storage of water supplies for more than 25 million people in three western states (California, Arizona, and Nevada). Storage within Lake Mead supplies drinking water and provides for the generation of hydropower to deliver electricity for major cities including Las Vegas, Phoenix, Los Angeles, Tucson, and San Diego. It also provides water for irrigation of more than 2.5 million acres (almost 4000 square miles or more than twice the size of the state of Delaware) of croplands. Major findings detailed in the report include the following:
The report was prepared cooperatively by the U.S. Geological Survey, National Park Service, U.S. Fish and Wildlife Service, Bureau of Reclamation, Nevada Department of Wildlife, Southern Nevada Water Authority, BIO-WEST, University of Nevada, Reno, and University of Nevada, Las Vegas. The full report, USGS Circular 1381, "A synthesis of aquatic science for management of Lakes Mead and Mohave," is available online. Note to editors: B-roll available from USGS upon request. |
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Media Advisory: Exploring the Earth's Crust – Seismology Uncovers Hidden Secrets Beneath Our Feet Posted: 18 Jan 2013 08:00 AM PST Free USGS Public Lecture January 24MENLO PARK, Calif. —A century of scientific creativity and innovation has allowed seismologists to "see" into the outer layers of our planet, revealing the deep properties of the Earth's crust. U.S. Geological Survey geophysicist Walter Mooney will explain how field measurements from the Tibetan plateau, the Pacific Ocean, and beyond have provided new insights and clues about processes that have been shaping the Earth for millions of years.
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Posted: 09 Jan 2013 09:15 AM PST SACRAMENTO, Calif. — Inorganic elements - arsenic, boron, fluoride, and five other inorganic elements - were detected at high concentrations in 35 percent of untreated groundwater used for public water supply in the desert region of southern California. In contrast, human-made organic chemical constituents and nitrate were found at high concentrations in less than 1 percent of the desert region’s aquifers. This study's findings are important, in part, because elsewhere in California, high concentrations of inorganic elements generally are found in 10 to 25 percent of the aquifer system used for public supply, nitrate in 1 to 8 percent, and human-made organic chemical constituents in up to 2 percent. "High" concentrations are defined as above the Environmental Protection Agency's or California Department of Public Health's established Maximum Contaminant Levels or other non-regulatory health-based levels for chemical constituents or elements not having MCLs. The U.S. Geological Survey did not analyze treated tap water. Water distributors typically treat water supplies prior to delivering it to customers to ensure compliance with water quality standards for human health. As part of a statewide study assessing groundwater quality, USGS scientists analyzed untreated groundwater from wells in the desert region between 2006 and 2008, looking for as many as 207 chemical constituents. California's desert region includes Antelope Valley, Coachella Valley, Indian Wells Valley, Owens Valley, Mojave River area, and the Colorado River basin. "Over a ten-year period, the USGS is characterizing groundwater quality in 120 groundwater basins and other areas that supply about 95 percent of public groundwater supplies," explained USGS director Marcia McNutt. "The new results for the desert region show where, what, and how much contamination is in the groundwater, focusing attention on improving water quality where it is needed." Naturally occurring inorganic elements were found in high concentrations in 22% of Owens Valley, 30% of Antelope Valley, 28% of the Mojave area, 42% of Coachella Valley, 45% of Colorado River basins, and 62% of Indian Wells Valley. In these areas with high concentrations, one or more of the following eight inorganic elements was found at high concentrations: arsenic, boron, fluoride, gross-alpha radioactivity, molybdenum, strontium, vanadium, and uranium. These elements are naturally present in rocks and soils, and the water that comes in contact with those materials. High concentrations generally are the result of natural processes, but human activities may have some influence. An additional 28 percent of the aquifer systems had moderate concentrations, greater than one-half the comparison level, of at least one inorganic constituent. In contrast, high concentrations of organic constituents (such as solvents, gasoline components, and pesticides) and nitrate were found in less than 1 percent of the desert region's aquifers. Perchlorate was found at high concentrations in 10% of Coachella Valley aquifers and was not found at high concentrations in any of the other areas. High concentrations of organic constituents, nitrate, and perchlorate are typically associated with human activity. "Local water distributors and regional, state, and federal agencies, as well as the US EPA, are aware of the presence of arsenic, fluoride, uranium, and other inorganic constituents in groundwater in the desert region, and are actively working to manage local groundwater resources and assure that water delivered to consumers meets water-quality standards," said Dr. Miranda Fram, chief of the USGS Groundwater Ambient Monitoring and Assessment program. "One of the most interesting results of this study was the contrast between the relatively large percentage of groundwater with high concentrations of inorganic elements and the small percentage with high concentrations of human-made organic constituents; this contrast is much larger in the desert region than in other parts of California," said Barbara Dawson, a USGS hydrologist and author of the report prepared in collaboration with the California State Water Resources Control Board. The USGS California Water Science Center is the technical lead for the State Water Resources Control Board GAMA Program's Priority Basin Project. The USGS is monitoring and assessing water quality in 120 priority groundwater basins, and groundwater outside of basins, across California over a ten-year period. The main goals of the State Water Board’s GAMA Program Priority Basin Project are to improve comprehensive statewide groundwater monitoring and to increase the availability of groundwater-quality information to the public. The full report and six accompanying non-technical Fact Sheets are available online:
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Media Advisory: Colorful South Pacific Species – New Discoveries and Looming Threats Posted: 10 Dec 2012 08:00 AM PST Free USGS Public Lecture December 13MENLO PARK, Calif. — Exciting discoveries are spurring research to uncover hidden secrets deep within South Pacific tropical forests. USGS Research Biologist Robert Fisher will be making an engaging presentation detailing new discoveries and emerging threats to wildlife and ecosystems. Join us on December 13th, to hear Fisher's stories from the tropical forests of Papua New Guinea and hear him detail his discovery of a new species dubbed the "bumblebee" gecko, and what he and other herpetologists are finding while studying Pacific lizard biodiversity.
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Media Advisory: USGS Science at AGU Posted: 30 Nov 2012 03:08 PM PST USGS Science at AGU SAN FRANCISCO — From over well over 500 abstracts by USGS presenters at this year’s American Geophysical Union conference, we’ve selected some of the newest, most exciting topics that USGS scientists will explore at AGU. Tips are presented in topic areas, chronologically with room numbers, session numbers and a summary. The AGU conference is held Dec. 3-7 at the Moscone Convention Center in San Francisco. News media representatives are invited to visit the USGS booth in the AGU Exhibit Hall. This is an easy place to connect with USGS and the staff working at the booth will have data, publications, and information.
News Conferences - Moscone West, Room 3000 Improving forecasts of “Pineapple Expresses” Monday, 12/3 at 1:30 p.m. – USGS’s Michael Dettinger and NOAA
Superstorm Sandy, Black Swan cyclones and the economic toll to come Monday, 12/3 at 4 p.m. – USGS’s Hilary Stockdon
Natural or man-made? Triggers and limits to induced earthquakes Wednesday, 12/5 at 1:30 p.m. USGS’s Art McGarr
How much carbon gets stored in western U.S. ecosystems? Wednesday, 12/5 at 2:30 p.m. – USGS Director Marcia McNutt and Ben Sleeter
SF Bay Area landslides Wednesday, 12/5, 4:45 p.m., MS 304 Landslide triggering: Monitoring and modeling conditions for regional shallow landslide initiation in the San Francisco Bay Area USGS scientist: Brian Collins NH34A-04/Oral presentation Pre-storm precipitation thresholds are not always sufficient to predict when and under what conditions landslides may occur. We installed subsurface monitoring stations at four landslide-prone San Francisco Bay area locations, measured soil moisture and positive pore water pressure directly, and are integrating these measurements into predictive analyses.
SF Bay-Delta Tuesday, 12/4, 1:40 p.m., MS Poster Hall Effect of microclimates on evapotranspiration rates, energy balance and water use estimation in the Sacramento-San Joaquin Delta USGS scientist: Frank Anderson B23E-0499/Poster This research focuses on the unique summer microclimate of the Sacramento-San Joaquin Delta region, which is often cool and moist compared to the surrounding area. As a result, our findings indicate that evapotranspiration rates in the Delta are lower than for similar crops grown outside the region. Our intention is to update resource models to reflect these reduced ET rates and generate more accurate water-use maps for this region of statewide hydrologic importance.
Monday, 12/3, 8 a.m., MS Poster Hall Tidal marsh accretion processes in the San Francisco Bay-Delta – are our models underestimating the historic and future importance of plant-mediated organic accretion? USGS scientist: Lisamarie Windham-Myers PP11D-2055/Poster Peat-accreting coastal wetlands can potentially keep pace with sea-level rise, mitigating expected rises in atmospheric greenhouse gases. Profiles of plant biomass and fossil remnants in active and past brackish-to-fresh peat deposits of the Bay-Delta suggest that potential rates of organic, as opposed to mineral, accretion may be underestimated, and that plant physiology is a significant factor in development of coastal peatlands. As suspended sediment concentrations are now decreasing in the area, organic accretion may be enhanced or sufficient for sustaining marsh elevations.
Hosgri-shoreline faults Thursday, 12/6, 1:40 p.m., MS Poster Hall Influence of fault trend, fault bends, and fault convergence on shallow structure, geomorphology, and hazards in the Hosgri strike-slip fault, offshore central California USGS scientist: Samuel Johnson OS43C-1841/Poster USGS mapped a portion of the right-lateral Hosgri Fault Zone from Point Sal to Piedras Blancas, creating perhaps the most comprehensive survey of the shallow structure of an active strike-slip fault. USGS estimates a lateral slip rate of 2-4 mm/yr and conclude that earthquake hazard assessments should incorporate a minimum rupture length of 110 km in this central California fault zone.
Tropical storms Press conference: Monday, 12/3 at 4 pm. Tuesday, 12/4, 4:33 p.m., MW 2022-2024 A nationally consistent method for assessing coastal vulnerability to hurricane-induced erosion USGS scientist: Hilary Stockdon OS24C-04/Oral presentation USGS combined beach morphology data with hydrodynamic models to predict likely response of beaches along the U.S Gulf of Mexico and Southeast coasts to direct landfall of tropical storms. USGS found that even the lowest category hurricane was very likely to inundate the Gulf, while Southeast beaches were higher in elevation and a bit less vulnerable. Changes to barrier islands will affect beaches’ vulnerability to future storms.
Volcano monitoring & forecasting Wednesday, 12/5, 1:40 p.m., MS Poster Hall Technology and geologic mapping at Newberry Volcano, Ore. USGS scientist: Julie Donnelly-Nolan V33B-2855/Poster Technological advances have provided powerful new tools for geologic mapping, including hand-held GPS receivers, digital map compilation, lidar land surface imagery and tablet computers. However, the technology cannot replace direct observations by the field geologist or critical data from argon chronology, paleomagnetism, petrology, geochemistry, and geophysics.
Volcanology, geochemistry and petrology Tuesday, 12/4, 2:10 p.m., MS 310 The application of unmanned aerial systems in geophysical investigations of geothermal systems USGS scientist: Jonathan Glen V23F-03/Oral presentation USGS and NASA researchers are developing unmanned aerial systems to collect magnetic data to map subsurface structures controlling geothermal fluids beneath northern California’s Surprise Valley. Onboard computers analyze sensor data and autonomously optimize flight paths to investigate regions of interest, allowing researchers to obtain uniform, high-resolution targeted data.
Tuesday, 12/4, 8 a.m., MS 310 Sorting out the magmatic from the hydrothermal: An example from Yellowstone USGS scientist: Jacob Lowenstern V21D-01/Oral presentation Magmatic heat and volatiles spur growth of hydrothermal systems and incorporate crustal and meteoric components as they evolve. At Yellowstone, some sites yield magmatic volatiles nearly unaffected by crust. At others, we see radiogenic helium released primarily from billion-year-old crust. The 2-million-year old Yellowstone magma-hydrothermal system is actively purging helium from crustal rocks that had accumulated radiogenic gas for much of Earth’s history.
Tuesday, 12/4, 8 a.m., MS Poster Hall A survey of Alaskan volcanoes using satellite and airborne thermal infrared USGS scientist: Rick Wessels V21B-2766/Poster ASTER acquires several images per year at every volcano on Earth to describe baseline thermal behavior and detect future volcanic unrest or eruption precursors. ASTER data has retrospectively revealed subtle variations in thermal activity at several Alaskan volcanoes. Temperatures slowly increased at Pavlof Volcano before the August 2007 eruption. ASTER data from the Redoubt Volcano summit area reveals a gradual increase in both the area and temperature of small gaps in the ice nearly 16 months before the 2009 eruption.
Water quality Wednesday, 12/5, 8 a.m., MS Poster Hall Global change and water availability and quality: Challenges ahead USGS scientist: Matthew Larsen H31I-1273/Poster America’s population growth rate in its most water-scarce states, its expansion of irrigated agriculture and its dispersal of record-high volumes of pharmaceutical and personal care products into surface and groundwater through treatment facilities not designed to treat them: All these constitute a continental-scale, multi-year water-resources experiment in which society has not defined testable hypotheses or set the duration and scope of the experiment. What are we doing? How can we change?
Extreme geophysical events, global disasters Wednesday, 12/5, 11:20 a.m., MS 300 Credible occurrence probabilities for extreme geophysical events USGS scientist: Jeffrey Love NG32A-01/Oral presentation Very few very large earthquakes, explosive volcanic eruptions, magnetic storms, and other extreme events have occurred in recorded history. How well can we predict their occurrence in the future based upon their rare occurrence in the past? We provide a means for confidently estimating the 10-year occurrence probabilities of extreme events in the future.
Natural hazards Monday, 12/3, 5:45p.m., MS 104 Quantifying the impacts of global disasters USGS scientist: Lucy Jones NH14A-08/Oral presentation Like the earlier ShakeOut and ARkStorm disaster scenarios, the Next Wave Tsunami Scenario applies science to quantify the impacts of a distant tsunami on the coast and ports of California so decision makers may reduce the potential for loss.
Tuesday, 12/4, 9:45 a.m., MW 3011 New imaging of submarine landslides near Whittier, Alaska, from the 1964 earthquake and a comparison to other 1964 failures in Alaskan fjords USGS Scientist: Peter J. Haeussler OS21G-08/Oral Presentation The largest cause of deaths in the M9.2 1964 Alaska earthquake was from local tsunamis caused by submarine landslides. We collected multibeam bathymetry and sparker seismic data in Passage Canal, near Whittier, to document what happened in 1964. We find evidence the neoglacial period likely brought abundant sediment to the fjords, causing this earthquake to produce especially large and numerous submarine landslides.
Special lecture: Tuesday, 12/4, 11:30 a.m., MS 103 “Defeating Earthquakes,” the Gilbert F. White Distinguished Award Lecture (a non-technical presentation with a weak/strong building demonstration) USGS scientist: Ross Stein NH22B-02/Oral presentation Close to a million people died in earthquakes during the past decade, but no one will take actions to construct strong buildings and strengthen weak ones unless they are convinced they are at risk. The Global Earthquake Model is a public-private partnership formed to address that need: It will produce the world’s first seismic risk model in 2014 so that everyone will understand their risk.
Wednesday, 12/5, 1:40 p.m., MS Poster Hall The 2001-present triggered seismicity sequence in the Raton Basin of southern Colorado/northern New Mexico USGS scientist: Justin Rubinstein S34A-02/Poster Examining the location, depth and regional tectonic regime of the Aug. 23, 2011 earthquake swarm in the Raton Basin of northern New Mexico and southern Colorado, we conclude that most if not all the seismicity since then has been triggered by the deep injection of wastewater related to the production of natural gas from the nearby coal-bed methane field.
Wednesday, 12/5, 1:40 p.m., MS Poster Hall USGS SAFRR Tsunami Scenario: Potential impacts to the U.S. West Coast from a plausible M9 earthquake near the Alaska Peninsula USGS scientist: Stephanie Ross NH33A-1639/Oral presentation Geologic similarities support the argument that an event similar to 2011’s Tohoku event is plausible in Alaska. The USGS Science Application for Risk Reduction (SAFRR) project, in collaboration with the California Geological Survey, the California Emergency Management Agency, NOAA and others is developing the Next Wave Tsunami Scenario to depict a hypothetical but plausible large tsunami originating from a M9 earthquake in the eastern Aleutians and its many impacts to the California coast.
Wednesday, 12/5, 3:10 p.m., MS 306 The 8 February 1843 Lesser Antilles earthquake: A “missing” great earthquake USGS scientist: Susan Hough T33H-07/Oral presentation The study sheds new light on the seismic potential of the Lesser Antilles subduction zone, suggesting it is capable of producing larger earthquakes than those experienced during the ~500-year historical period. The study further reveals how conventional analysis can significantly underestimate the size of great earthquakes prior to the start of the instrumental era in seismology (roughly 1900).
Thursday, 12/6, 8 a.m., MS Poster Hall Geologic evidence for a tsunami source along the trench northeast of Puerto Rico USGS scientist: Brian Atwater T41A-2566/Poster From comparison with the traces of storms and tsunamis of the past 200-350 years, we conclude that the curious reef corals now scattered on an island east-northeast of Puerto Rico were not deposited by a storm surge, or by the famous 1755 Lisbon tsunami, but instead by a tsunami of nearby origin that probably took place in the last centuries before Columbus.
Thursday, 12/6, 12:05 p.m., MS 304 Stakeholder-driven geospatial modeling for assessing tsunami vertical-evacuation strategies in the U.S. Pacific Northwest USGS scientist: Nathan Wood NH42A-08/Oral presentation Vertical-evacuation options are berms or structures that aid evacuations during natural disasters. Looking at communities along the southwest coast of Washington state that are threatened by tsunami hazards generated by Cascadia subduction-zone earthquakes, we developed geospatial tools to automate parts of the pedestrian-evacuation models and indicate where VE options might be placed.
Mercury Tuesday, 12/4, 1:40 p.m., MW 2003 Toward a unified understanding of mercury and methylated mercury from the world’s oceans USGS scientists: USGS Director Marcia McNutt, David Krabbenhoft B23K-01/Oral presentation Marine fish and shellfish are the main sources of toxic methylmercury exposure for humans, although understanding its distribution across ocean basins has remained elusive. Seawater profiles (surface to 1000 m) from the Pacific, Indian and Antarctic oceans provide insights into the processes controlling the production and distribution of methylmercury. This information is used to develop a marine methylmercury production model, which reveals relative differences in methylmercury concentrations across the world’s oceans.
Tuesday, 12/4, 2:40 p.m., MW 2003 Watershed responses to changes in mercury loading: Results from the terrestrial aspects of the METAALICUS project USGS scientist: David Krabbenhoft B23K-05/Oral presentation The Mercury Experiment to Assess Atmospheric Loadings in Canada and the US (METAALICUS) project addresses concerns that ubiquitous mercury contamination may render emission regulations ineffective by deliberately adding enriched mercury isotopes to an entire watershed at the Experimental Lakes Area in northwest Ontario, Canada, from 2001 to 2006. Two years after loading ceased, isotope levels in canopy and emission fluxes were negligible and about half the total isotope load was found in soils, where it remains steady. Isotope levels in runoff gradually increased during the loading phase and continued to do so for 1-2 years after loading ceased, suggesting significant translocation from compartments above the forest floor.
Tuesday, 12/4, 9:40 a.m., MW 2006 Implications for ecosystem services of watershed processes that affect the transport and transformations of mercury in an Adirondack stream basin USGS scientist: Douglas Burns B21H-07/Oral presentation Five years of data collection of stream water, groundwater, invertebrates and fish in the upper Hudson River basin indicate that factors such as watershed geomorphology, seasonal variations in discharge and air temperature, and the location and connection of riparian wetlands to streams are the strongest factors that affect stream MeHg concentrations and therefore, the potential ecosystem services provided by fish and other wildlife in the Adirondack region.
Thursday, 12/6, 10:35 a.m., MW 2018 Relative influence of aquatic and terrestrial processes on methylmercury transport in river basins USGS scientist: Douglas Burns H42D-02/Oral presentation Most MeHg in small river basins originates at the interface of the terrestrial and aquatic ecosystem in zones with anaerobic conditions and abundant organic matter. Its transport into food webs is influenced by subsurface hydraulic conductivity and water-table depth, while open-water bodies are sources for MeHg loss. Burns will discuss how these factors affect aquatic MeHg concentrations in river basins in New York’s Adirondack Mountains and the coastal plain of South Carolina, and model seasonally varying buildup of MeHg in riparian soils.
Human interest/Diversity in the workforce It’s the 21st century. Are women’s issues still relevant in the workplace?
Monday, 12/3, 1:40 p.m., MS Poster Hall Recipe for an eclectic life as research scientist and mom USGS scientist: Jennifer Harden ED13A-0769/Poster A soils scientist and veteran USGS researcher gives tips for success in grad school, locating mentors, career decisions, the work-family balance and other whole-life choices. Hint: Choose profs and mentors “whose lifestyles seem like good examples.” See also Oral portion of the session ED11D
Monday, 12/3, 6:15 p.m., MW 2002 Exploring solutions for diverse science workforce USGS scientists: USGS Director Marcia McNutt, Jennifer Harden TH15A/Oral presentation We discuss potential solutions and gather input from AGU members on how organizations can nurture excellence and personal success for women in all stages of their science careers.
Post-dam river restoration (with or without removing the dam) Monday, 12/3, 1:40 p.m., MS Poster Hall Evolution of a dammed river: Trajectories of geomorphic change on the Trinity River, Calif. USGS scientist: Jennifer Curtis EP13A-0821/Poster Beginning in 2001, the Trinity River Restoration Program implemented a combination of flow releases, gravel augmentation, bank rehabilitation and watershed restoration to promote dynamic channel processes. To inform the restoration work, we digitized a series of geomorphic maps and quantified the nature, extent and rates of geomorphic change during five post-dam time periods. The systemwide perspective reveals three distinct phases of evolving geomorphic features, channel changes and reactivation of alluvial units initiated by natural flow events and restoration actions.
Friday, 12/7, 8:45 a.m., MW 2008 Hydraulics of embankment-dam breaching USGS scientist: Joseph Walder EP51D-04/Oral presentation To better understand hazards from overtopping failure of earthen dams, we are conducting experiments at the USGS debris-flow flume with dams built from beach sand, with the hydraulics and breach evolution characterized by sensor arrays within the dams and cameras both overhead and submerged. Results challenge assumptions made in mathematical models that are commonly used for hazards assessment.
Elwha: Rebirth of a river The removal in 2011 of the Glines Canyon and Elwha dams represented one of the largest such projects in North America. USGS and partners characterized baseline conditions before the dams’ removal and will continue to study the watershed during its ongoing restoration.
Monday, 12/3, 1:40 p.m., MS Poster Hall Sedimentary deposits and processes in the lower Elwha River, Wash., USA, during dam removal USGS scientist: Amy Draut EP13E-0886/Poster This session discusses new fine sediment and organic matter between gravel and cobble grains that could have substantial ecosystem effects. New sediment deposits were evident throughout the lower river in spring 2012 of a much finer grain size than before dam removal began.
Monday, 12/3, 1:40 p.m., MS Poster Hall The turbid coastal plume of the Elwha River during dam removal USGS scientist: Jonathan Warrick EP13E-0888/Poster Hydrology: We characterize the river, estuarine and coastal turbidity caused by this unprecedented project using remote sensing imagery, time-lapse photography, moored instrumentation and sampling directly within the plume that extends into the Strait of Juan de Fuca.
Friday, 12/7, 4:45 p.m., MW 2003 Initial coastal morphologic response to dam removal on the Elwha River, Wash. USGS scientist: Guy Gelfenbaum EP54C-04/Oral Presentation Geomorphology: We investigate the initial morphologic response of the submarine delta to increased sediment delivery using a combination of field measurements of morphological change in combination with numerical modeling.
Monday, 12/3, 1:40 p.m., MS Poster Hall Suspended-sediment load in the lower Elwha River, Wash., during early stages of dam decommissioning USGS scientist: Christopher Magirl EP13E-0890/Poster Sedimentation: More than 500,000 metric tons of sediment flowed down the Elwha in the first nine months of the dams’ decommissioning. We characterize the suspended-sediment load and compare it to expected levels.
Friday, 12/7, 4:30 p.m., MW 2003 First-year dam removal activities in the Elwha River – dam removal, sediment dispersal, and fish relocations USGS scientist: Jeffrey Duda EP54C-03/Oral Presentation Fisheries: Our data show that Pacific steelhead and salmon are already beginning to recolonize the Elwha watershed, historically a rich habitat for native anadromous species.
Monday, 12/3, 1:40 p.m., MS Poster Hall Elwha River riparian vegetation response to dams and dam removal EP13E-0891/Poster USGS scientist: Patrick Shafroth Geomorphology and vegetation: We characterize the pioneer plant communities taking root on newly exposed reaches downstream from the dam sites.
Subsidence Wednesday, 12/5, 8 a.m., MS Poster Hall Refurbished extensometer sites improve the quality and frequency of aquifer-system compaction and groundwater-level measurements, San Joaquin Valley USGS scientist: Michelle Sneed NH31A-1591/Poster Importing groundwater into the San Joaquin Valley since the 1960s has helped to mitigate extensive land subsidence and aquifer compaction. But surface-water availability has been reduced, leading to more groundwater pumping, lowered water levels, renewed compaction and subsidence and reduced capacity of important canals. The USGS science team refurbished four 1960s extensometers along the Delta-Mendota Canal and California Aqueduct to identify subsidence, improve compaction measurements and ultimately help calculate aquifer storage properties. Since future stresses on the system are likely, continued monitoring will assist managers of water conveyance systems and water-banking strategies.
Climate change Friday, 12/7, 2:25 p.m., MW 2006 Monitoring global food security with new remote sensing products and tools USGS scientist: Michael E Budde B53H-04/Poster In recent years, it has become apparent that FEWS NET requires the ability to apply monitoring and modeling frameworks at a global scale to assess potential impacts of foreign production and markets on food security at regional, national, and local levels. We present early warning monitoring tools, and show advancements in existing ones, namely, the Early Warning eXplorer and interactive rainfall and NDVI time series viewers.
Tuesday, 12/4, 11:20 a.m., MW 3008 Sharing the rivers: Balancing the needs of people and fish against the backdrop of heavy sediment loads downstream from Mount Rainier, Wash. USGS scientist: Christopher Magirl GC22C-05/Oral presentation Pronounced glacier retreat on Mount Rainier coupled with large floods have produced dynamic, sediment-laden rivers that impact people. Some data indicate floods and sedimentation may be increasing in magnitude, although other data sets indicate that Pacific Ocean sea-surface temperature more strongly influences Mount Rainier hydrology in decadal time scales than does global climate change.
Monday, 12/3, 8:00 a.m., MS Poster Hall Timing is everything: Using near-surface and remote sensing to monitor vegetation phenology in sagebrush steppe USGS scientist: Geneva Chong B11C-0441/Poster Near-surface, fine-scale measurements of vegetation greenness are used to monitor plant phenology as an indicator of sagebrush vegetation condition and the effectiveness of management actions including cheatgrass herbicide treatments and sagebrush disturbance and restoration. |
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