A5013838085- Hydrology and Sediment Transport Processes
- Soil erosion and sediment transport
- Geology and Paleoclimatology Research
- Hydrology and Watershed Management Studies
- Geological formations and processes
- Evolution and Paleontology Studies
- Marine Biology and Ecology Research
- Paleontology and Stratigraphy of Fossils
- Marine and environmental studies
- Geological and Geochemical Analysis
- Aeolian processes and effects
- Cephalopods and Marine Biology
- Water Quality and Resources Studies
- Flood Risk Assessment and Management
- Archaeology and Natural History
- Archaeology and ancient environmental studies
- Pacific and Southeast Asian Studies
- Subterranean biodiversity and taxonomy
- Hydrocarbon exploration and reservoir analysis
- Morphological variations and asymmetry
- Marine and coastal plant biology
- Remote Sensing and LiDAR Applications
- Isotope Analysis in Ecology
- Fish Ecology and Management Studies
- Fire effects on ecosystems
Northern Arizona University
2001-2022
UCLA Health
2014
Louisiana State University
1988-1995
Kanazawa University
1992
United States Geological Survey
1969-1988
Louisiana State University Agricultural Center
1963
Uranium-series dating of corals from marine deposits the U.S. Atlantic Coastal Plain coupled with paleoclimatic reconstructions based on ostracode (marine) and pollen (continent) data document at least five relatively warm intervals during last 500,000 years. On basis multiple paleoenvironmental criteria, we determined relative sea level positions intervals, to present mean level, were 7 +/- 5 meters 188,000 years ago, 7.5 1.5 120,000 6.5 3.5 94,000 3 72,000 ago. The composite chronology for...
Ostracodes were identified from 236 bottom samples taken in the region Nova Scotia to Long Island. There is a distinctive difference between assemblages northern and southern parts of this region. Many sublittoral cryophilic species are not present south Cape Cod or Northeast Channel, several thermophilic a.re .found north Georges Bank. The ostracode part cold-temperate Scotian province mixture amphiatlantic endemic, mainly species; European forms make up approximately 50 percent species....
Research Article| November 01, 1970 Binary Coefficients and Clustering in Biostratigraphy JOSEPH E HAZEL U.S. Geological Survey, E-501 National Museum, Washington, D.C. 20242 Search for other works by this author on: GSW Google Scholar Author Article Information Publisher: Society of America Received: 24 Apr Revision 25 Jun First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print 0016-7606 Copyright © 1970, The America, Inc. is not claimed on any material prepared government employees within...
Abstract Measurements of morphologic change are often used to infer sediment mass balance. Such measurements may, however, result in gross errors when changes over short reaches extrapolated predict balance for long river segments. This issue is investigated by examination and influx efflux a 100 km segment the Colorado River Grand Canyon, Arizona. For each four monitoring intervals within 7 year study period, direction sand‐storage response was consistent with flux‐based sand Both budgeting...
The 1996 controlled flood released from Glen Canyon Dam into the Colorado River was a small magnitude, short duration event compared to pre-dam floods. of lesser magnitude than 1.25-yr recurrence, and only 10% spring snowmelt floods during period 1922–1962 were lower magnitude. occurred unusually early: 36–38 d prior any previous annual since 1922. stage difference between flood's peak recessional baseflow smaller in those years similar or volume. However, large perspective post-dam regime....
Glen Canyon Dam has caused a fundamental change in the distribution of fine sediment storage 99‐km reach Colorado River Marble Canyon, Grand National Park, Arizona. The two major sites for (i.e., sand and finer material) this canyon river are lateral recirculation eddies main‐channel bed. We use combination methods, including direct measurement change, measurements flux, comparison grain size found different relative to supply that transport, order evaluate both volume location storage....
Q-mode dendrogram and trellis diagram based on calculation of Dice similarity coefficients._____________________3. Chart showing suggested biostratigraphic position Yorktown samples used in analysis.__.-____--_.____4. R-mode for 80 ostracode species that occur five or more samples.-______--__-__--___-_-.-________ 5. Map location containing brackish-water elements_______-_-
Abstract Effects of riparian vegetation on fluvial sediment dynamics depend morphological traits the constituent species. Determining effects different guilds sedimentation rates, as influenced by multiple aspects dam operations, can help identify viable strategies for streamflow and management to achieve resource goals. Plants increasing size branching density or complexity have been found greater in free‐flowing systems; however, this relationship could differ regulated rivers. We tested...
Impact-glass microspherules occur at numerous localities in rocks that can be dated as late Eocene. There is debate to whether the discovered microspherule layers are result of two or three impact events. Standard biostratigraphic techniques have been employed date layers. However, analysis available data indicates zonal biostratigraphy has insufficient for task, particularly if practiced with only one taxonomic group. A chronostratigraphic framework model constructed using Graphic...
A 60-hour release of water at 1,203 cubic meters per second (m3/s) from Glen Canyon Dam in March 2008 provided an opportunity to analyze channel-margin response discharge levels above the normal, diurnally fluctuating releases for hydropower plant operations. We compare measurements sandbars and associated campsites along mainstem Colorado River, downstream Dam, 57 locations Marble Grand Canyons. Sandbar main-channel high-flow experiment (2008 HFE) was documented by measuring bar bed...
Abstract Morphological change in river channels is frequently evaluated the context of mass balance sediment budgets. In a closed budget, measurements influx and efflux are coupled with measured changes channel topography to provide both spatial temporal resolution, independent estimates balance. For budgets constructed over long segments (~10 2 widths or greater) periods (~2 years longer), accumulation measurement uncertainty, compounded by inadequate sampling frequency coverage, may...