scholarly journals Long-term fault slip rates, distributed deformation rates, and forecast of seismicity in the western United States from joint fitting of community geologic, geodetic, and stress direction data sets

2009 ◽  
Vol 114 (B11) ◽  
Author(s):  
Peter Bird
Keyword(s):  
United States ◽  
Fault Slip ◽  
Western United States ◽  
Data Sets ◽  
Slip Rates ◽  
Stress Direction ◽  
Fault Slip Rates

scholarly journals Long term fault slip rates, distributed deformation rates and forecast of seismicity in the Iranian Plateau

Tectonics ◽  
2015 ◽  
Vol 34 (10) ◽  
pp. 2190-2220 ◽  
Author(s):  
A. Khodaverdian ◽  
H. Zafarani ◽  
M. Rahimian
Keyword(s):  
Fault Slip ◽  
Iranian Plateau ◽  
Slip Rates ◽  
Fault Slip Rates

An investigation on possibilty of creep on the Makran subduction zone based on deformation data

2020 ◽  
Author(s):  
Homa Ghadimi Moghaddam ◽  
Alireza Khodaverdian ◽  
Hamid Zafarani
Keyword(s):  
Subduction Zone ◽  
Weighted Least Squares ◽  
Element Model ◽  
Fault Slip ◽  
Deformation Model ◽  
Slip Rates ◽  
Makran Subduction Zone ◽  
Fault Slip Rates ◽  
Seismic Deformation

<p>Long term crustal flow of the Makran subduction zone is computed with a kinematic finite element model based on iterated weighted least squares fits to data. Data include 91 fault traces, 56 fault offset rates, 76 geodetic velocities, 1962 principal stress azimuths, and velocity boundary conditions. Model provides long-term fault slip rates, velocity, and distributed permanent strain rates between faults in the Makran region from all available kinematic data. Due to low seismicity of western Makran compared to its eastern part we defined two models to evaluate the possibility of creep in the Iranian Makran subduction. One model assumes that geodetic velocities measured adjacent to the Makran subduction zone reflect a temporarily locked subduction zone will be referred to as the “seismic deformation model”. In contrast, another model called the “half creeping deformation model” assumes that the western part of Makran may creep smoothly without any locking. In order to verify the models, the estimates of fault slip rates are compared to slip rates from merely analysing geodetic benchmark velocities or paleoseismological studies or published geological rates which have not been used in the model. Our estimated rates are all in the range of geodetic rates and are even more consistent with geological rates than previous GPS-based estimates. Another verification for the model is comparison of the computed interseismic velocities at GPS benchmarks to GPS measurements. While neither model accurately predicts these interseismic velocities at benchmarks, the half creeping deformation model is more accurate for Chabahar station than the seismic deformation model. These results have important earthquake and tsunami hazard implications. For example, Fault slip rates are the main component of time-dependent seismic hazard studies and can be used to estimate activity rates for more sophisticated earthquake models.</p>

Asian Americans and Pacific Islanders: Employment Issues in the United States

2011 ◽  
Vol 9 (1-2) ◽  
pp. 58-69
Author(s):  
Marlene Kim
Keyword(s):  
United States ◽  
Asian Americans ◽  
The United States ◽  
Current Data ◽  
Pacific Islanders ◽  
Native Hawaiians ◽  
Data Sets ◽  
High Poverty ◽  
Unemployment Rates

Asian Americans and Pacific Islanders (AAPIs) in the United States face problems of discrimination, the glass ceiling, and very high long-term unemployment rates. As a diverse population, although some Asian Americans are more successful than average, others, like those from Southeast Asia and Native Hawaiians and Pacific Islanders (NHPIs), work in low-paying jobs and suffer from high poverty rates, high unemployment rates, and low earnings. Collecting more detailed and additional data from employers, oversampling AAPIs in current data sets, making administrative data available to researchers, providing more resources for research on AAPIs, and enforcing nondiscrimination laws and affirmative action mandates would assist this population.

Warming is Driving Decreases in Snow Fractions While Runoff Efficiency Remains Mostly Unchanged in Snow-Covered Areas of the Western United States

2018 ◽  
Vol 19 (5) ◽  
pp. 803-814 ◽  
Author(s):  
Gregory J. McCabe ◽  
David M. Wolock ◽  
Melissa Valentin
Keyword(s):  
United States ◽  
Time Series ◽  
Winter Precipitation ◽  
Western United States ◽  
Balance Model ◽  
Winter Temperatures ◽  
Long Term Trends ◽  
Monthly Water Balance ◽  
Surface Water Supply

Abstract Winter snowfall and accumulation is an important component of the surface water supply in the western United States. In these areas, increasing winter temperatures T associated with global warming can influence the amount of winter precipitation P that falls as snow S. In this study we examine long-term trends in the fraction of winter P that falls as S (Sfrac) for 175 hydrologic units (HUs) in snow-covered areas of the western United States for the period 1951–2014. Because S is a substantial contributor to runoff R across most of the western United States, we also examine long-term trends in water-year runoff efficiency [computed as water-year R/water-year P (Reff)] for the same 175 HUs. In that most S records are short in length, we use model-simulated S and R from a monthly water balance model. Results for Sfrac indicate long-term negative trends for most of the 175 HUs, with negative trends for 139 (~79%) of the HUs being statistically significant at a 95% confidence level (p = 0.05). Additionally, results indicate that the long-term negative trends in Sfrac have been largely driven by increases in T. In contrast, time series of Reff for the 175 HUs indicate a mix of positive and negative long-term trends, with few trends being statistically significant (at p = 0.05). Although there has been a notable shift in the timing of R to earlier in the year for most HUs, there have not been substantial decreases in water-year R for the 175 HUs.

Sign in / Sign up

Export Citation Format

Share Document