scholarly journals Characteristics of mantle fabrics beneath the south-central United States: Constraints from shear-wave splitting measurements

Geosphere ◽  
2008 ◽  
Vol 4 (2) ◽  
pp. 411 ◽  
Author(s):  
Stephen S. Gao ◽  
Kelly H. Liu ◽  
Robert J. Stern ◽  
G. Randy Keller ◽  
John P. Hogan ◽  
...  
Keyword(s):  
United States ◽  
Shear Wave ◽  
Shear Wave Splitting ◽  
The South ◽  
South Central ◽  
Wave Splitting ◽  
Central United States

A Uniform Database of Teleseismic Shear‐Wave Splitting Measurements for the Western and Central United States: December 2014 Update

2016 ◽  
Vol 87 (2A) ◽  
pp. 295-300 ◽  
Author(s):  
Bin B. Yang ◽  
Kelly H. Liu ◽  
Haider H. Dahm ◽  
Stephen S. Gao
Keyword(s):  
United States ◽  
Shear Wave ◽  
Shear Wave Splitting ◽  
Wave Splitting ◽  
Central United States

scholarly journals A uniform database of teleseismic shear wave splitting measurements for the western and central United States

2014 ◽  
Vol 15 (5) ◽  
pp. 2075-2085 ◽  
Author(s):  
Kelly H. Liu ◽  
Ahmed Elsheikh ◽  
Awad Lemnifi ◽  
Uranbaigal Purevsuren ◽  
Melissa Ray ◽  
...  
Keyword(s):  
United States ◽  
Shear Wave ◽  
Shear Wave Splitting ◽  
Wave Splitting ◽  
Central United States

scholarly journals Flow plane orientation in the upper mantle under the Western/Central United States from SKS shear-wave splitting observations

2020 ◽  
Vol 221 (2) ◽  
pp. 1125-1137
Author(s):  
Eric Löberich ◽  
Götz Bokelmann
Keyword(s):  
United States ◽  
Shear Wave ◽  
Upper Mantle ◽  
Seismic Anisotropy ◽  
Shear Wave Splitting ◽  
Azimuthal Dependence ◽  
Additional Information ◽  
Wave Splitting ◽  
Central United States ◽  
Flow Plane

SUMMARY The causes of seismic anisotropy are still under debate. In particular, it is important to understand the extent to which seismic anisotropy is due to more recent geodynamic activities in the asthenosphere, or to frozen-in deformation in the lithosphere. We show that these two endmember cases can in principle be distinguished using shear-wave splitting observations from SKS waves. This is illustrated by the simple example of pure olivine with horizontal a-axis, and differing orientations of the other two axes, namely, vertical b and vertical c. The azimuthal dependence of shear-wave splitting measurements is described by two parameters, which can provide additional information about subsurface deformation. In particular, the oscillation parameter d1 constrains the orientation of foliation. We demonstrate that shear-wave splitting in the Western and Central United States indeed shows the predicted azimuthal dependence, related to a mainly subhorizontally oriented flow plane of deformation in the upper mantle. This has important implications for asthenospheric flow.

Community Resilience to Drought Hazard in the South-Central United States

2017 ◽  
Vol 108 (3) ◽  
pp. 739-755 ◽  
Author(s):  
Volodymyr V. Mihunov ◽  
Nina S. N. Lam ◽  
Lei Zou ◽  
Robert V. Rohli ◽  
Nazla Bushra ◽  
...  
Keyword(s):  
United States ◽  
Community Resilience ◽  
The South ◽  
Drought Hazard ◽  
South Central ◽  
Central United States

scholarly journals Aeroallergens and Climate Change in Tulsa, Oklahoma: Long-Term Trends in the South Central United States

2021 ◽  
Vol 2 ◽  
Author(s):  
Estelle Levetin
Keyword(s):  
Climate Change ◽  
United States ◽  
Pollen Season ◽  
Maximum Temperature ◽  
The South ◽  
South Central ◽  
Pollen Types ◽  
Central United States ◽  
Total Pollen

Climate change is having a significant effect on many allergenic plants resulting in increased pollen production and shifts in plant phenology. Although these effects have been well-studied in some areas of the world, few studies have focused on long-term changes in allergenic pollen in the South Central United States. This study examined airborne pollen, temperature, and precipitation in Tulsa, Oklahoma over 25 to 34 years. Pollen was monitored with a Hirst-type spore trap on the roof of a building at the University of Tulsa and meteorology data were obtained from the National Weather Service. Changes in total pollen intensity were examined along with detailed analyses of the eight most abundant pollen types in the Tulsa atmosphere. In addition to pollen intensity, changes in pollen season start date, end date, peak date and season duration were also analyzed. Results show a trend to increasing temperatures with a significant increase in annual maximum temperature. There was a non-significant trend toward increasing total pollen and a significant increase in tree pollen over time. Several individual taxa showed significant increases in pollen intensity over the study period including spring Cupressaceae and Quercus pollen, while Ambrosia pollen showed a significant decrease. Data from the current study also indicated that the pollen season started earlier for spring pollinating trees and Poaceae. Significant correlations with preseason temperature may explain the earlier pollen season start dates along with a trend toward increasing March temperatures. More research is needed to understand the global impact of climate change on allergenic species, especially from other regions that have not been studied.

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