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Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

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At least 181 records · Page 10Linked to original sources
USGS2006

Major improvements in progress for Southern California Earthquake Monitoring

Major improvements in seismic and strong-motion monitoring networks are being implemented in southern California to better meet the needs of emergency response personnel, structural engineers, and the research community in promoting earthquake hazard reduction. Known as the TriNet project, the improvements are being coordinated by the California Institute of Technology (Caltech), the U.S. Geological Survey (USGS), and the California Division of Mines and Geology (CDMG) of the state's Department of Conservation. Already the ambitious instrument and system development project has started to record and disseminate ground motions from a spatially dense and robust network of high quality seismographs.

Eos, Transactions, American Geophysical Union↗
USGS2006

Satellite radar interferometry measures deformation at Okmok Volcano

The center of the Okmok caldera in Alaska subsided 140 cm as a result of its February– April 1997 eruption, according to satellite data from ERS-1 and ERS-2 synthetic aperture radar (SAR) interferometry. The inferred deflationary source was located 2.7 km beneath the approximate center of the caldera using a point source deflation model. Researchers believe this source is a magma chamber about 5 km from the eruptive source vent. During the 3 years before the eruption, the center of the caldera uplifted by about 23 cm, which researchers believe was a pre-emptive inflation of the magma chamber. Scientists say such measurements demonstrate that radar interferometry is a promising spaceborne technique for monitoring remote volcanoes. Frequent, routine acquisition of images with SAR interferometry could make near realtime monitoring at such volcanoes the rule, aiding in eruption forecasting.

Eos, Transactions, American Geophysical Union↗
USGS2011

Seismic survey probes urban earthquake hazards in Pacific Northwest

A multidisciplinary seismic survey earlier this year in the Pacific Northwest is expected to reveal much new information about the earthquake threat to U.S. and Canadian urban areas there. A disastrous earthquake is a very real possibility in the region. The survey, known as the Seismic Hazards Investigation in Puget Sound (SHIPS), engendered close cooperation among geologists, biologists, environmental groups, and government agencies. It also succeeded in striking a fine balance between the need to prepare for a great earthquake and the requirement to protect a coveted marine environment while operating a large airgun array.

Washington↗
USGS2011

Debating complexity in modeling

Complexity in modeling would seem to be an issue of universal importance throughout the geosciences, perhaps throughout all science, if the debate last year among groundwater modelers is any indication. During the discussion the following questions and observations made up the heart of the debate. As scientists trying to understand the natural world, how should our effort be apportioned? We know that the natural world is characterized by complex and interrelated processes. Yet do we need to explicitly incorporate these intricacies to perform the tasks we are charged with? In this era of expanding computer power and development of sophisticated preprocessors and postprocessors, are bigger machines making better models? Put another way, do we understand the natural world better now with all these advancements in our simulation ability? Today the public's patience for long-term projects producing indeterminate results is wearing thin. This increases pressure on the investigator to use the appropriate technology efficiently. On the other hand, bringing scientific results into the legal arena opens up a new dimension to the issue: to the layperson, a tool that includes more of the complexity known to exist in the real world is expected to provide the more scientifically valid answer.

Eos, Transactions, American Geophysical Union↗
USGS2011

Airborne laser study quantifies El Niño-induced coastal change

Winter storms during the 1997–1998 El Niño caused extensive changes to the beaches and cliffs of the west coast of the United States, a NASA-NOAA-USGS investigation using a scanning airborne laser has found. For example, near Pacifica in central California, the cliff eroded locally as much as 10–13 m landward during the El Niño winter, at least 40 times the long term average erosion rate. However, only several hundred meters away the cliff was stable. This variability in cliff response may be related to differences in local beach changes where an accreting beach protected part of the cliff and an eroding beach exposed another part to attack by waves.

Pacific Coast↗
USGS2011

The U.S. Geological Survey's gravity program in the Rocky Mountain and Basin Range areas

Most of the gravity surveys of the U.S. Geological Survey have been support programs in connection with regional geologic structural studies, ground-water investigations, and heavy-metals exploration. Many of the studies were undertaken in conjunction with geological mapping and mineral investigations by the Survey's project geologists. Gravity data often complement aeromagnetic surveys to identify the sources of potential-field anomalies; other gravity data have been used to supplement high-resolution seismic and electrical investigations [ Mattick , 1967]. Geochemical follow-up has been fruitful in western Montana [ Mudge et al, 1967].

Arizona, Colorado, Idaho, Montana, Nevada, New Mex↗
USGS2011

IASH Commission of Snow and Ice meeting: Paris, France, September 3-5, 1969

The IASH Commission of Snow and Ice met jointly with the Working Group on Glaciology of the Special Committee on Antarctic Research (SCAR). Five technical guides have been prepared by the Commission of Snow and Ice for major IHD projects and have been in press at Unesco for more than a year and a half. They should be published by December 1969. A sixth guide, on Sea, Lake and River Ice, was approved for publication, and two other guides (Avalanche Classification and Part 2 of Combined Heat, Ice, and Water Balances) have been distributed in first or second draft form. They should be ready for approval by the next meeting of the officers of the Commission. Even though these guides have not yet been officially published, they have served as instruction and coordination media for a large number of glacier and seasonal snow cover projects in many nations during the first part of the International Hydrological Decade.

Eos, Transactions, American Geophysical Union↗
USGS2011

A progress report: Water conservation by removal of phreatophytes

Evapotranspiration from the flood plain of a major river depletes the water contributed from upstream areas of the watershed. This depletion can be significant in arid regions where water supplies are inadequate. Phreatophyte control offers a method of reducing the evapotranspiration and thus increases the water available to downstream users. This control is achieved by removing the woody phreatophytes and replacing them with grasses having a lower consumptive use.

Arizona↗
USGS2011

International symposium on hydrometry

Approximately 520 engineers and scientists from 55 countries attended the International Symposium on Hydrometry held at Koblenz, Federal Republic of Germany, from September 13 through 22, 1970. The symposium was convened by Unesco and organized in cooperation with the World Meteorological Organizations (WMO), Unesco, the National Committee for the International Hydrological Decade of the Federal Republic of Germany, and the International Association of Scientific Hydrology (IASH). The symposium was organized within the framework of the International Hydrological Decade (IHD). After a welcoming speech by J. Wallner, Chairman of the Organizing Committee, the opening address was presented by S. Dumitrescu, the representative of Unesco. Introductory statements were then delivered by T. Palas, the representative of WMO; by L.J. Tison, the representative of IASH; and by K. Wittock, the representative of the Government of the Federal Republic of Germany.

Eos, Transactions, American Geophysical Union↗
USGS2012

Geochemistry of water

The quadrennium 1967–1970 has been a productive period in the field of water geochemistry. Field studies, laboratory investigations, and theoretical considerations have led to significant advances in our knowledge of the chemical behavior of natural waters and of the solid earth materials that contain them. A symposium on trace inorganics in water, sponsored by the American Chemical Society, was held in Miami, Florida, in 1967. The proceedings of this conference were published in 1968 in the Advances in Chemistry Series 73. This volume deals with the occurrence, behavior, and analysis of inorganic constituents in natural waters.

Eos, Transactions, American Geophysical Union↗
USGS2012

The problem of groundwater discharge into the seas

Introductory Note: The dynamic equilibrium of the various factors involved in the world water balance or budget is the central scientific problem of the International Hydrological Decade. One of the potentially vital elements of the balance is groundwater discharge to the oceans. To paraphrase the authors of the following Russian publication, the world water budget can't be properly balanced, statically or dynamically, until there are improved values for the amount of groundwater that is discharged directly to oceans, seas, and enclosed lakes. The following report, with its bibliography, presents some Russian approaches to the problem and provides a few bits of numerical information. The report was translated by Frank W. Trainer of the U.S. Geological Survey. The text has been slightly reduced in the interests of saving space but the bibliography is given in full and has been transcribed into more or less standard U.S. Geological Survey bibliographical style. ©1971. American Geophysical Union. All Rights Reserved.

Eos, Transactions, American Geophysical Union↗
USGS2011

Water projects design with inadequate data: Madrid, Spain June 4-9, 1973

The Symposium on the Design of Water Resources Projects with Inadequate Data drew 300 participants, representing more than 60 countries. The symposium was planned within the framework of the International Hydrological Decade and was convened by Unesco and WMO. Organization of the symposium was carried out by Unesco and the Spanish National Committee for the IHD in cooperation with WMO and the IAHS. These organizations are to be commended for their efforts toward ensuring the success of the symposium. The efforts of the Spanish National Committee, which handled the many local arrangements, are especially appreciated.

Madrid↗
USGS2011

Earthquake mechanism and displacement fields close to fault zones: Report on the Sixth GEOP Research Conference

The Sixth Geodesy/Solid Earth and Ocean Physics (GEOP) Research Conwas held on February 4–5, 1974, at the Institute of Geophysics and Planetary Physics, University of California, San Diego, in La Jolla, California. It was attended by about 100 persons. James N. Brune, program chairman, opened the conference and delivered the introductory address, a somewhat extended version of which is printed elsewhere in this issue. Brune's paper and the following summaries of the sessions constitute a report of the conference.

Eos, Transactions, American Geophysical Union↗
USGS2011

Ocean margin drilling - a multifaceted picture

While many in the oceanographic community enthusiastically look forward to the Ocean Margin Drilling (OMD) program, others are not sure that the science to be gained will be worth the commitment to such an expensive, technology-intensive venture. The program was 7 years in the planning at the National Science Foundation (NSF), calls for a total cost of about $700 million over the next decade, and is to last through 1989. OMD was envisioned at the NSF as the next step after the enormously successful Glomar Challenger Deep-Sea Drilling Project (DSDP). Now winding down, DSDP is scheduled to continue through 1981 and taper off in 1982. A proposal has been submitted that would extend Challenger operations through 1983.

Eos, Transactions, American Geophysical Union↗
USGS2011

Water resources of the People's Republic of China

At the invitation of the Society of Hydraulic Engineers of the People's Republic of China (PRC), a delegation of U.S. hydrologists and hydraulic engineers visited the PRC in the fall of 1978.* From discussions with officials of both the Society and the Ministry of Water Conservancy and Power (MWCP), and from visits to research and academic institutions and water projects, the delegation gained a general understanding of the country's surface water resources. The reported statistics, supplemented with others from published sources, provide a quantitative description of the PRC's water resources in relation to those of the United States.

Eos, Transactions, American Geophysical Union↗
USGS2011

Hydrology comes of age: Impact of the International Hydrological Decade

The IHD (International Hydrological Decade), 1965 to 1974, was conceived as a concerted international effort to bring into focus the badly fragmented subdiscipline of hydrology, to evolve a global perspective on water, and to provide global information on water. Until the last decade or so, hydrology was a laggard science. The science was also fragmented among surface‐water hydrology, agricultural hydrology, groundwater hydrology, oceanology, hydrometeorology, and hydrogeochemistry. All these disciplines were bona fide members of the hydrological family, but there was little interchange, so there was no central focus for the science as a whole. ©1980. American Geophysical Union. All Rights Reserved.

Eos, Transactions, American Geophysical Union↗