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Articles 1 - 21 of 21

Full-Text Articles in Geology

Island Arcs, Accretionary Terranes And Midcontinent Structure New Understandings Of The Geologic Architecture Of The U.S. Midcontinent, Marvin P. Carlson Oct 2001

Island Arcs, Accretionary Terranes And Midcontinent Structure New Understandings Of The Geologic Architecture Of The U.S. Midcontinent, Marvin P. Carlson

Conservation and Survey Division

A data base collected over the last 100 years, containing both surface and subsurface information, has allowed us to begin to understand the physical framework of Nebraska. We have learned that even in the stable Midcontinent region of North America, there has been an active geologic history. This framework has been deciphered by our programs of surface geologic mapping and by the study of rock samples from both water wells and those deeper test wells for oil and gas. Determining the major structural features across the state (figure 1) has allowed us to better understand both the occurrences of its …


Environmental Change And The Central Great Plains, Carbon Sequestration, Mark A. Mesarch Aug 2001

Environmental Change And The Central Great Plains, Carbon Sequestration, Mark A. Mesarch

Conservation and Survey Division

No abstract provided.


Environmental Change And The Central Great Plains, David Gosselin Apr 2001

Environmental Change And The Central Great Plains, David Gosselin

Conservation and Survey Division

No abstract provided.


Environmental Change And The Central Great Plain, Water Resources, David Gosselin Apr 2001

Environmental Change And The Central Great Plain, Water Resources, David Gosselin

Conservation and Survey Division

No abstract provided.


Agricultural Management Practices And The Groundwater System Of Northern Holt County, Nebraska, With A Focus On The Holt County Groundwater Education Project, Susan Olafsen Lackey, Charles Shapiro, William Kranz Apr 2001

Agricultural Management Practices And The Groundwater System Of Northern Holt County, Nebraska, With A Focus On The Holt County Groundwater Education Project, Susan Olafsen Lackey, Charles Shapiro, William Kranz

Conservation and Survey Division

No abstract provided.


Nebraska's Test-Hole Drilling Program And Records, Duane R. Mohlman, Charles A. Flowerday Mar 2001

Nebraska's Test-Hole Drilling Program And Records, Duane R. Mohlman, Charles A. Flowerday

Conservation and Survey Division

No abstract provided.


Geology Of Pioneers Park, Lancaster County, Nebraska, Roger K. Pabian Mar 2001

Geology Of Pioneers Park, Lancaster County, Nebraska, Roger K. Pabian

Conservation and Survey Division

No abstract provided.


In-Cave Dye Tracing And Drainage Basin Divides In The Mammoth Cave Karst Aquifer, Kentucky, Chris Groves, Joe Meiman, Shannon Herstein Feb 2001

In-Cave Dye Tracing And Drainage Basin Divides In The Mammoth Cave Karst Aquifer, Kentucky, Chris Groves, Joe Meiman, Shannon Herstein

Earth, Environmental, and Atmospheric Sciences Faculty Publications

Karst ground-water basin divides are generally depicted as two-dimensional lines on maps, but they are better considered as three-dimensional surfaces within the subsurface. Dye traces are necessary to map out these surfaces and to locate conduits inaccessible to cave surveyors, and are indispensable for understanding the geometry of the complex networks of flow paths through the aquifer. A key reason why the Mammoth Cave System is the world's longest known cave is that its passages extend over several major ground-water basins. The divides between these basins define the drainage system geometry and precise location of them is critical for understanding …


In-Cave Dye Tracing And Drainage Basin Divides In The Mammoth Cave Karst Aquifer, Kentucky, Chris Groves, Joe Meiman, Shannon Herstein Feb 2001

In-Cave Dye Tracing And Drainage Basin Divides In The Mammoth Cave Karst Aquifer, Kentucky, Chris Groves, Joe Meiman, Shannon Herstein

Chris Groves

Karst ground-water basin divides are generally depicted as two-dimensional lines on maps, but they are better considered as three-dimensional surfaces within the subsurface. Dye traces are necessary to map out these surfaces and to locate conduits inaccessible to cave surveyors, and are indispensable for understanding the geometry of the complex networks of flow paths through the aquifer. A key reason why the Mammoth Cave System is the world's longest known cave is that its passages extend over several major ground-water basins. The divides between these basins define the drainage system geometry and precise location of them is critical for understanding …


Refined Kinematics Of The Eastern California Shear Zone From Gps Observations, 1993-1998, M. Meghan Miller, Timothy H. Dixon, Roy K. Dokka Feb 2001

Refined Kinematics Of The Eastern California Shear Zone From Gps Observations, 1993-1998, M. Meghan Miller, Timothy H. Dixon, Roy K. Dokka

All Faculty Scholarship for the College of the Sciences

Global Positioning System (GPS) results from networks spanning the Eastern California shear zone and adjacent Sierra Nevada block, occupied annually between 1993 and 1998, constrain plate margin kinematics. We use an elastic block model to relate GPS station velocities to long‐term fault slip rate estimates. The model accounts for elastic strain accumulation on the San Andreas fault, as well as faults of the Eastern California shear zone. South of the Garlock fault, 14 mm/yr of dextral shear is distributed across the Eastern California shear zone. Some of this slip penetrates eastward into the Basin and Range, and a collective budget …


Long Recurrence Records From The Wasatch Fault Zone, Utah, James P. Mccalpin Jan 2001

Long Recurrence Records From The Wasatch Fault Zone, Utah, James P. Mccalpin

James P. McCalpin

The Wasatch fault "megatrench" was excavated in September 1999 across two fault scarps totaling 18 meters high on the Salt Lake City segment of the Wasatch fault zone (WFZ). The purpose of the megatrench was to date a long series of consecutive earthquakes (8-12 events?) on the WFZ and measure the variability of recurrence times between the events.This variability could then be used in calculating the future probability of large earthquakes on the WFZ. The trench was located 1 km north of the mouth of Little Cottonwood Canyon, at an elevation of 1525 m, between the Bonneville highstand (ca. 17.5 …


Paleoseismicity Of Quaternary Faults Near Albuquerque, New Mexico: The Zia Fault, James P. Mccalpin Jan 2001

Paleoseismicity Of Quaternary Faults Near Albuquerque, New Mexico: The Zia Fault, James P. Mccalpin

James P. McCalpin

This study continues USGS-funded efforts to assess the activity and earthquake hazard potential of Quaternary faults in the Albuquerque metropolitan region. Our target in 2000 was the Zia fault, a 37 km-long normal fault that trends N-S in northern Llano de Albuquerque (LdA). The Zia fault is one of three major east-dipping normal faults that define the western margin of the Rio Grande rift in the northern Albuquerque basin, the other faults being the Calabacillas fault (to the west of the Zia fault) and the County Dump fault (to the east of the Zia fault) (Machette et al., 1998). In …


Population Characteristics And Food Habitats Of White Perch (Morone Americana) In Branched Oak, Nebraska, Cara Hodking Jan 2001

Population Characteristics And Food Habitats Of White Perch (Morone Americana) In Branched Oak, Nebraska, Cara Hodking

Conservation and Survey Division

No abstract provided.


Ecoregions Of Nebraska And Kansas, Robert F. Diffendal Jr. Jan 2001

Ecoregions Of Nebraska And Kansas, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources; they are designed to serve as a spatial framework for the research, assessment, management, and monitoring of ecosystems and ecosystem components. Ecoregions are directly applicable to the immediate needs of state agencies, including the development of biological criteria and water quality standards, and the establishment of management goals for nonpoint-source pollution. They are also relevant to integrated ecosystem management, an ultimate goal of most federal and state resource management agencies. The approach used to compile this map is based on the premise …


At-Satellite Reflectance: A First Order Normalization Of Landsat 7 Etm+ Images, Chengquan Huang, Limin Yang, Collin Homer, Bruce K. Wylie, James E. Vogelmann, Thomas Defelice Jan 2001

At-Satellite Reflectance: A First Order Normalization Of Landsat 7 Etm+ Images, Chengquan Huang, Limin Yang, Collin Homer, Bruce K. Wylie, James E. Vogelmann, Thomas Defelice

Publications of the US Geological Survey

Regional Landsat applications often rely on clear and near cloud-free images. With the spectral value being represented by digital number (DN), however, such images contain substantial noises. A significant proportion of such noises can be normalized by converting the DN to at-satellite reflectance value. Being physically based and ready to automate, the conversion method can serve as a first order normalization of Landsat 7 images, making it possible to derive land surface information from such images more consistently.


A Strategy For Estimating Tree Canopy Density Using Landsat 7 Etm+ And High Resolution Images Over Large Areas, C. Huang, Limin Yang, Bruce K. Wylie, Collin Homer Jan 2001

A Strategy For Estimating Tree Canopy Density Using Landsat 7 Etm+ And High Resolution Images Over Large Areas, C. Huang, Limin Yang, Bruce K. Wylie, Collin Homer

Publications of the US Geological Survey

INTRODUCTION

The Multi-Resolution Land Characteristics (MRLC) consortium was initiated in early 1990s to address the need for consistently developed national and regional land cover data (Loveland and Shaw, 1996). Through this consortium, a 1992-vintage National Land Cover Dataset (NLCD) was developed for the conterminous United States (Vogelmann et al., 2001), and a second generation National Land Cover Dataset (NLCD 2000) will be developed using 2000-vintage Landsat 7 Enhanced Thematic Mapper Plus (ETM+) images and ancillary data. The 2000 NLCD will consist of a suite of data layers relevant to many applications, including a tree canopy density layer describing percentage of …


Field Trip Guide (For The Nebraska Well Drillers Association) Western Nebraska Geology, J. Cannia, D. Weinert, D. Brost, C. Miller, D. Carlson Jan 2001

Field Trip Guide (For The Nebraska Well Drillers Association) Western Nebraska Geology, J. Cannia, D. Weinert, D. Brost, C. Miller, D. Carlson

Conservation and Survey Division

No abstract provided.


Resource Notes-Academic Year 2000-01 Jan 2001

Resource Notes-Academic Year 2000-01

Conservation and Survey Division

No abstract provided.


Adams County Test Hole Logs, Perry B. Wigley Jan 2001

Adams County Test Hole Logs, Perry B. Wigley

Conservation and Survey Division

No abstract provided.


Logan County Test Hole Logs, Perry B. Wigley Jan 2001

Logan County Test Hole Logs, Perry B. Wigley

Conservation and Survey Division

No abstract provided.


Saunders County Test Hole Logs, Raymond R. Burchett, Scott E. Summerside Jan 2001

Saunders County Test Hole Logs, Raymond R. Burchett, Scott E. Summerside

Conservation and Survey Division

No abstract provided.