Jon Campbell ( Phone: 703-648-4180 );
USGS collects a wide range of hydrologic data, assures the quality of these data, and makes historical and continuing records of the nation’s water resources freely available in national databases. USGS scientists have recently published two separate papers that provide national overviews of the status of USGS water resources information in the context of historical and technical developments in the last half-century.
Robert M. Hirsch and Gary T. Fisher (retired) point out in “Past, Present, and Future of Water Data Delivery from the U.S. Geological Survey” that USGS innovations, aided by rapidly improving technology, have enabled a transition in recent years from paper reports to online reports and from daily data to instantaneous data. An increasing emphasis on national and international data standards and web services makes it possible for users in the water management and research communities to quickly and easily import USGS water data into the operational and scientific software tools that they use. Further, distributing water data with applications on new mobile platforms brings value to new and nontraditional consumers of hydrologic information.
Writing in the May 2014 edition of Water Resources Impact, USGS Chief Scientist for Water Jerad D. Bales reviews (PDF) 1974 predictions of how water data would be collected in the future and notes how those predictions have been fulfilled or altered. He also describes factors, both technical and otherwise, affecting changes in water-resources data collection and management, as well as future challenges for water data collection.
Robert M. Hirsch and Gary T. Fisher. “Past, Present, and Future of Water Data Delivery from the U.S. Geological Survey” in Journal of Contemporary Water Research & Education, Universities Council on Water Resources, Issue 153, April 2014, pp. 4-15.
Jerad D. Bales. “Progress in Data Collection and Dissemination in Water Resources – 1974-2014” (PDF) in Water Resources IMPACT, May 2014, v. 16, no. 3, pp. 18-23.
Pharmaceuticals, personal-care products, and other contaminants are widespread in water that has passed through landfill waste. The samples of this liquid, also known as leachate, were collected from within each of the studied landfills. This study by the U.S. Geological Survey is the first national assessment of these chemicals of emerging concern in landfill leachate in the United States.
USGS scientists collected leachate from 19 active landfills and analyzed it for 202 chemicals across a wide range of uses, including pharmaceuticals, hygiene products, home-use chemicals, pesticides, plastics, etc. Of those 202 chemicals, 129 were found.
“This represents the first step in USGS efforts to quantify the contribution of contaminants of emerging concern in leachate from active landfills to the environment,” said Dana Kolpin, USGS, the research team leader. “Follow-up research will examine contaminant concentrations in treated and untreated leachate that is released to the environment.”
Of the chemicals found, concentrations varied. Steroid hormone concentrations generally ranged from 1 to 100’s nanograms per liter (ng/L, or parts per trillion); prescription and nonprescription pharmaceutical concentrations generally ranged from 100 to 10,000’s ng/L; and home-use and industrial chemical concentrations generally ranged from 1,000 to 1,000,000’s ng/L.
The 19 active landfills are located all across the United States and represent a snapshot of the various conditions that affect landfills.
“As expected, we found more chemicals and generally higher concentrations in landfills from wetter regions compared to those from drier regions,” said USGS scientist Jason Masoner, the primary author of this paper. “Overall, this study provides a better understanding of sources of contaminants of emerging concern in landfills.”
Chemicals commonly detected include:
- bisphenol A—detected in 95 percent of samples, used to make plastics and resins
- cotinine—detected in 95 percent of samples, a chemical formed from nicotine
- N,N-diethyltoluamide—detected in 95 percent of samples, also known as DEET
- lidocaine—detected in 89 percent of samples, used as anti-itching and local anesthetic
- camphor—detected in 84 percent of samples, used in a variety of medicines and lotions
This study is part of a long-term effort to determine the fate and effects of contaminants of emerging concern and to provide water-resource managers with objective information that assists in the development of effective water management practices.
The paper is entitled “Contaminants of Emerging Concern in Fresh Leachate from Landfills in the Conterminous United States” and has been published in Environmental Science: Processes & Impacts. More information on this study and other studies on contaminants of emerging concern can be found here. To learn more about USGS environmental health science, please visit the USGS Environmental Health website and sign up for our GeoHealth Newsletter or our Environmental Health Headlines.
Robin Fergason ( Phone: 928-556-7034 );
TEMPE, Ariz. – A heat-sensing camera designed at Arizona State University has provided data to create the most detailed global map yet of Martian surface properties. The map uses data from the Thermal Emission Imaging System (THEMIS), a nine-band visual and infrared camera on NASA’s Mars Odyssey orbiter. An online version of the map optimized for scientific researchers is also available.
The new Mars map was developed by Robin Fergason of the U.S. Geological Survey Astrogeology Science Center in Flagstaff, Arizona, in collaboration with researchers at ASU's Mars Space Flight Facility. The work reflects the close ties between space exploration efforts at Arizona universities and the USGS.
"We used more than 20,000 THEMIS nighttime temperature images to generate the highest resolution surface property map of Mars ever created," said Fergason, who earned her Ph.D. degree at ASU in 2006. "Now these data are freely available to researchers and the public alike."
Surface properties tell geologists about the physical nature of a planet or moon's surface. Is a particular area coated with dust, and if so, how thick is it likely to be? Where are the outcrops of bedrock? How loose are the sediments that fill this crater or that valley? A map of surface properties lets scientists begin to answer such questions.
The new map uses nighttime temperature images to derive the "thermal inertia" for football field-sized areas of Mars. Thermal inertia is a calculated value that represents how fast a surface heats up and cools off. As night follows day on Mars, loose fine-grain materials such as sand and dust change temperature quickly and thus have low values of thermal inertia. Bedrock has a high thermal inertia because it cools off slowly at night and warms up slowly by day.
"Darker areas in the map have a lower thermal inertia and likely contain fine particles, such as dust, silt or fine sand," said Fergason. “Brighter regions have higher thermal inertia surfaces, consisting perhaps of coarser sand, surface crusts, rock fragments, bedrock or combinations of these materials.”
The designer and principal investigator for the THEMIS camera is Philip Christensen, Regents' Professor of Geological Sciences in the School of Earth and Space Exploration, part of the College of Liberal Arts and Sciences on the Tempe campus. Four years ago, Christensen and ASU researchers used daytime THEMIS images to create a global Mars map depicting the planet's landforms, such as craters, volcanoes, outflow channels, landslides, lava flows and other features.
"A tremendous amount of effort has gone into this great global product, which will serve engineers, scientists and the public for many years to come," Christensen said. "This map provides data not previously available and will enable regional and global studies of surface properties. I'm eager to use it to discover new insights into the recent surface history of Mars."
Fergason noted that there's a practical side, too.
"NASA used THEMIS images to find safe landing sites for the Mars Exploration Rovers in 2004 and Curiosity, the Mars Science Laboratory rover, in 2012," she said. "THEMIS images are now helping to select a landing site for NASA's next Mars rover in 2020."
Jennifer LaVista ( Phone: 303-202-4764 );
Seasonal carbon dioxide frost, not liquid water, is the main driver in forming gullies on Mars today, according to a recent U.S. Geological Survey study that relied on NASA’s Mars Reconnaissance Orbiter’s (MRO) repeated high-resolution observations.
Martian gullies are landforms typically consisting of steep channels, usually having a recessed head, that feed into a fan of material deposited at the bottom. The discovery of active gullies was first reported in 2000, which generated excitement due to consideration that they might result from action of liquid water. Mars has water vapor and plenty of water ice, but liquid water, a necessity for all known life, has not been confirmed on modern Mars. The new report, published in the journal Icarus, is available online.
"As recently as five years ago, I thought the gullies on Mars indicated activity of liquid water," said USGS scientist Colin Dundas, lead author of the new report. "We were able to get many more observations, and as we started to see more activity and pin down the timing of gully formation and change, we saw that the activity is in winter."
A smaller type of seasonal flow seen on some slopes on Mars may involve liquid water, but is yet to be determined. These flows are called recurring slope lineae (RSL), and are sometimes found within small channels but not systematically associated with larger gullies.
Dundas and collaborators used the High Resolution Imaging Science Experiment (HiRISE) camera on MRO to examine each of 356 Martian sites with gullies at least twice, beginning in 2006. Thirty-eight of the sites showed activity, such as cutting a new channel segment or adding material to the apron-shaped deposit at the downhill end of a gully. Wherever the timing of before-and-after observations enabled determining the season of gully activity, it was a time too cold for the possibility of melting water-ice, but consistent with seasonal carbon dioxide frost.
"RSL and mass movements in Martian gullies are two distinct types of slope activity,” said Dundas “It's not hard to tell them apart in HiRISE images. The classic Martian gullies are much larger than RSL. Many of them are more the size that you'd call ravines on Earth."
Frozen carbon dioxide, commonly called dry ice, does not exist naturally on Earth, but it is plentiful on Mars. It has been linked to active processes on Mars such as geysers of carbon dioxide gas from springtime sublimation of dry ice, and blocks of dry ice that plow lines on sand dunes by sledding down dunes on cushions of sublimated gas. One mechanism for how carbon dioxide frost might drive gully flows is by gas that is sublimating from the frost, providing lubrication for dry material to flow. Another might be slides due to accumulating weight of seasonal frost buildup on steep slopes.
Work by Dundas and others has previously pointed to winter timing of gully formation on dune and non-dune slopes, with suggested involvement of seasonal changes in frozen carbon dioxide. The new report adds evidence for the changes. The findings also make a new point that the pace of gully formation that has now been documented is swift enough that all of the fresh-appearing gullies seen on Mars can be attributed to current processes. Some earlier hypotheses attributing the gullies to action of liquid water have suggested they formed thousands to millions of years ago when climate conditions were possibly more conducive to Mars having liquid water due to variations in the planet's tilt and orbit.
Dundas' co-authors on the new report are Serina Diniega of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, and Alfred McEwen of the University of Arizona, Tucson.
"Much of the information we have about gully formation and other active processes on Mars comes from the longevity of MRO and other orbiters,” said Diniega. “This enables repeated observation of sites to examine changes over time."
Data will appear in an upcoming special issue of Icarus with multiple reports about active processes on Mars, including RSL.
"I like that Mars can still surprise us," Dundas said. "Martian gullies are fascinating features where we can investigate a process that we just don't see on Earth."
HiRISE is operated by the University of Arizona. The instrument was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. The Mars Reconnaissance Orbiter Project is managed for NASA's Science Mission Directorate, Washington, by JPL.
Visit the USGS Astrogeology Center to learn more.
Visit HiRISE for more information.
Additional information about MRO is available online.These two images show changes in a gully on Mars, and illustrate that these landforms are evolving rapidly. A rubbly flow (noted by the arrows) has been deposited near the mouth of the channel between the time of the two images. Further up the slope, the channel system has been modified by both erosion and deposition. The timing of such changes is often in winter or early spring, suggesting that they are caused by the carbon dioxide frost that forms in and around most gullies every year. (High resolution image)