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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 109 records · Page 6Linked to original sources
USGS1978

Lower Tertiary coal bed distribution and coal resources of the Reno Junction-Antelope Creek area, Campbell, Converse, Niobrara, and Weston counties, Wyoming

The Powder River Basin of Wyoming and Montana contains some of the world's most extensive deposits of low sulfur subbituminous coal. The major coal beds occur in the upper part of the Fort Union and lower part of the Wasatch Formations of early Tertiary age (deposited about 60 to 50 million years ago). Most of the coal beds have been given informal names by local workers; names used in the Reno Junction-Antelope Creek area are shown on the fence diagram and on the sample well logs (fig. 1). Conditions leading to the formation of these coal deposits in the geologic past are discussed by R. W. Brown (1958, 1962).

Wyoming↗
USGS2005

SEGY to ASCII Conversion and Plotting Program 2.0

INTRODUCTION SEGY has long been a standard format for storing seismic data and header information. Almost every seismic processing package can read and write seismic data in SEGY format. In the data processing world, however, ASCII format is the 'universal' standard format. Very few general-purpose plotting or computation programs will accept data in SEGY format. The software presented in this report, referred to as SEGY to ASCII (SAC), converts seismic data written in SEGY format (Barry et al., 1975) to an ASCII data file, and then creates a postscript file of the seismic data using a general plotting package (GMT, Wessel and Smith, 1995). The resulting postscript file may be plotted by any standard postscript plotting program. There are two versions of SAC: one version for plotting a SEGY file that contains a single gather, such as a stacked CDP or migrated section, and a second version for plotting multiple gathers from a SEGY file containing more than one gather, such as a collection of shot gathers. Note that if a SEGY file has multiple gathers, then each gather must have the same number of traces per gather, and each trace must have the same sample interval and number of samples per trace. SAC will read several common standards of SEGY data, including SEGY files with sample values written in either IBM or IEEE floating-point format. In addition, utility programs are present to convert non-standard Seismic Unix (.sux) SEGY files and PASSCAL (.rsy) SEGY files to standard SEGY files. SAC allows complete user control over all plotting parameters including label size and font, tick mark intervals, trace scaling, and the inclusion of a title and descriptive text. SAC shell scripts create a postscript image of the seismic data in vector rather than bitmap format, using GMT's pswiggle command. Although this can produce a very large postscript file, the image quality is generally superior to that of a bitmap image, and commercial programs such as Adobe Illustrator? can manipulate the image more efficiently.

Open-File Report↗
USGS2009

Evaluation of Ground-Motion Modeling Techniques for Use in Global ShakeMap - A Critique of Instrumental Ground-Motion Prediction Equations, Peak Ground Motion to Macroseismic Intensity Conversions, and Macroseismic Intensity Predictions in Different Tectonic Settings

Regional differences in ground-motion attenuation have long been thought to add uncertainty in the prediction of ground motion. However, a growing body of evidence suggests that regional differences in ground-motion attenuation may not be as significant as previously thought and that the key differences between regions may be a consequence of limitations in ground-motion datasets over incomplete magnitude and distance ranges. Undoubtedly, regional differences in attenuation can exist owing to differences in crustal structure and tectonic setting, and these can contribute to differences in ground-motion attenuation at larger source-receiver distances. Herein, we examine the use of a variety of techniques for the prediction of several ground-motion metrics (peak ground acceleration and velocity, response spectral ordinates, and macroseismic intensity) and compare them against a global dataset of instrumental ground-motion recordings and intensity assignments. The primary goal of this study is to determine whether existing ground-motion prediction techniques are applicable for use in the U.S. Geological Survey's Global ShakeMap and Prompt Assessment of Global Earthquakes for Response (PAGER). We seek the most appropriate ground-motion predictive technique, or techniques, for each of the tectonic regimes considered: shallow active crust, subduction zone, and stable continental region.

Open-File Report↗
USGS2010

Unintended consequences of biofuels production?The effects of large-scale crop conversion on water quality and quantity

In the search for renewable fuel alternatives, biofuels have gained strong political momentum. In the last decade, extensive mandates, policies, and subsidies have been adopted to foster the development of a biofuels industry in the United States. The Biofuels Initiative in the Mississippi Delta resulted in a 47-percent decrease in cotton acreage with a concurrent 288-percent increase in corn acreage in 2007. Because corn uses 80 percent more water for irrigation than cotton, and more nitrogen fertilizer is recommended for corn cultivation than for cotton, this widespread shift in crop type has implications for water quantity and water quality in the Delta. Increased water use for corn is accelerating water-level declines in the Mississippi River Valley alluvial aquifer at a time when conservation is being encouraged because of concerns about sustainability of the groundwater resource. Results from a mathematical model calibrated to existing conditions in the Delta indicate that increased fertilizer application on corn also likely will increase the extent of nitrate-nitrogen movement into the alluvial aquifer. Preliminary estimates based on surface-water modeling results indicate that higher application rates of nitrogen increase the nitrogen exported from the Yazoo River Basin to the Mississippi River by about 7 percent. Thus, the shift from cotton to corn may further contribute to hypoxic (low dissolved oxygen) conditions in the Gulf of Mexico.

Open-File Report↗
USGS2017

Conversing with Pelehonuamea: A workshop combining 1,000+ years of traditional Hawaiian knowledge with 200 years of scientific thought on Kīlauea volcanism

The events surrounding volcanic eruptions and damaging earthquakes in Hawai‘i have often been described in journals, letters, and newspapers articles in the English language; however, the Hawaiian nation was among the most literate of countries in the 19th century, and many Hawaiian-language newspapers were in circulation through all but the earliest decades of the 19th century. Any modern reconstruction of the history of Hawaiian eruptions or earthquakes should take advantage of all available sources, and so we seek to add the Hawaiian-language newspaper articles, journals, stories, and chants to the volcano and earthquake literature. These sources have been used in many recent volcanological studies. Another aspect to the mix of science and traditional Hawaiian values is that many of the volcanic summits in Hawaiʻi are considered sacred to Hawaiians. Hawaiian travelers brought the first Western missionary team to the summit of Kīlauea and advised them of the proper protocols and behaviors while in this sacred area. The missionaries dismissed this advice as native superstition and they began a campaign of aggressively stamping out customs and protocols related to the Hawaiian volcano goddess Pelehonuamea. What has survived as native knowledge of the volcanoes is a few phrases from native guides included in some of the missionaries’ journals, and a few stories. Pualani and Ku ʻ ulei Kanahele provide excellent introductions to the Pelehonuamea chants. In the 21st century, amid a reawakening of Hawaiian culture, modern Hawaiians are demanding protection of their sacred areas, and scientists must be aware of these interests. At the very least, scientists should show respect to Hawaiian values when working in these areas, and should try to minimize disruptions caused by their work. Kaeo Duarte, Peter Mills, and Scott Rowland describe taking this approach in their field work. Traditional knowledge is also contained in place names. It is important not only to preserve old place names and to recover those no longer used, but also to preserve the stories of those places. Bobby Camara talks about the joys and frustrations of getting information on and recovering Hawaiian place names. Finally, we hope that a broader interest in Hawaiian views about locations in Hawaiʻi where physical scientific work is done will be as beneficial to physical scientists as it has been to life scientists investigating Hawaiian lifeforms on land and in the ocean, and that both studies will continue to benefit the native peoples of Hawaiʻi. Note that these proceedings are transcripts of oral presentations illustrated with PowerPoint presentations or charts. Although every effort has been made to assure the accuracy of the oral presentations, there are some gaps where words are not discernible in the voice recordings and are so noted. In other places, bracketed words were added to clarify the speaker’s meaning.

Hawaii↗