scholarly journals Reconnaissance field investigation of the Landers earthquake (Ms 7.5) of June 28, 1992,
 San Bernadino County, California, USA

1992 ◽  
Vol 25 (3) ◽  
pp. 230-241
Author(s):  
Kelvin Berryman
Keyword(s):  
Los Angeles ◽  
Field Investigation ◽  
Fault Rupture ◽  
Epicentral Area ◽  
Landers Earthquake ◽  
Rupture Length ◽  
California Institute Of Technology ◽  
Institute Of Technology ◽  
Relationship Of ◽  
The Relationship

The Landers earthquake (Ms 7.5) occurred at 4.58 am local time, and was located about 10 km north of the town of Yucca Valley, close to the small town of Landers, and about 170 km ENE of Los Angeles (Fig. 1). At the time the author was in Reno, Nevada, involved in a field study of the 1915 rupture of the Pleasant Valley fault. Fieldwork was completed on July 8, and on July 9 the author drove with a Reno-based colleague, Dr. Steven Wesnousky, firstly to Los Angeles to consult with seismologists and geologists at U. S. Geological Survey (Pasadena) and California Institute of Technology (Caltech), and then to Yucca Valley to inspect surface faulting and damage in the epicentral area. We reached Yucca Valley at about 6 pm on July 10, and remained in the area until the evening of July 14. Some objectives in inspecting the fault rupture were to look at the distribution of slip along the length of the fault break; the relationship of faulting to pre-existing traces; and the relationship of the fault rupture to the total length of each of the faults that ruptured. The earthquake magnitude and total rupture length are similar to what has been proposed for the segment of the Wellington fault that runs through the Wellington metropolitan area.

scholarly journals Modeling of energy amplification recorded within Greater Los Angeles using irregular structure

1994 ◽  
Vol 84 (1) ◽  
pp. 47-61 ◽  
Author(s):  
Chandan K. Saikia ◽  
Douglas S. Dreger ◽  
Donald V. Helmberger
Keyword(s):  
Los Angeles ◽  
Surface Waves ◽  
Transfer Functions ◽  
Long Beach ◽  
Low Velocity ◽  
Time Duration ◽  
California Institute Of Technology ◽  
Downtown Los Angeles ◽  
Institute Of Technology ◽  
Energy Amplification

Abstract We have investigated energy amplification observed within Greater Los Angeles basin by analyzing regional waveforms recorded from several Nevada Test Site (NTS) nuclear explosions. Although the stations are located nearly at the same azimuth (distances ranging from 350 to 400 km), the seismograms recorded in Compton (the central part of the basin), Long Beach (the southern edge of the basin), and downtown Los Angeles are remarkably different, even for a common explosion. Following the onset of Lg waves, the Long Beach sites have recorded surface waves for more than 100 sec. From one explosion, the sites within downtown Los Angeles have recorded seismograms with strong 3-sec surface waves. These waves are not observed on the seismograms recorded in the neighboring hard-rock site California Institute of Technology (CIT) station. Thus, they must have been generated by local wave guides. Numerically, we modeled these 3-sec waves by convolving the CIT seismogram with the response of a sedimentary strata dipping gently (about 6°) from CIT toward downtown. We also examined the irregular basin effect by analyzing the variation of cumulative temporal energy across the basin relative to the energy recorded at CIT from the same explosion. Variation up to a factor of 30 was observed. To model the energy variation that is caused by extended surface waves in the Long Beach area, we used numerically simulated site transfer functions (STF) from a NNE-SSW oriented two-dimensional basin structure extending from Montebello to Palos Verdes that included low-velocity sedimentary material in the uppermost layers. These STFs were convolved with the CIT seismogram recorded from the MAST explosion. To simulate elongated duration of surface waves, we introduced in the upper sedimentary structure some discontinuous microbasin structures of varying size, each microbasin delaying the seismic waves propagating through them. Consequently, the surface-reflected phases through these structures are delayed and reflected into the upper medium by the underlying interfaces. This mechanism helps delayed energy to appear at a later time and result in a longer time duration at sites located at southern edge of the basin.

Types and Areal Distribution of Ground Failure Associated with the 2019 Ridgecrest, California, Earthquake Sequence

2020 ◽  
Vol 110 (4) ◽  
pp. 1567-1578 ◽  
Author(s):  
Randall W. Jibson
Keyword(s):  
Epicentral Distance ◽  
Wide Band ◽  
Field Investigation ◽  
Earthquake Sequence ◽  
Lateral Spread ◽  
Fault Rupture ◽  
Rock Falls ◽  
Epicentral Area ◽  
Ground Failure ◽  
Almost All

ABSTRACT The July 2019 Ridgecrest, California, earthquake sequence included the largest earthquake (M 7.1) to strike the conterminous United States in the past 20 yr. To characterize the types, numbers, and areal distributions of different types of ground failure (landslides, liquefaction, and ground cracking), I conducted a field investigation of ground failure triggered by the sequence around the periphery of the epicentral area (which had limited access). The earthquake sequence triggered sparse and widely scattered landslides over an area of ∼22,000  km2 and at a maximum epicentral distance of 114 km; these metrics are within the upper bounds as compared with global averages for earthquakes of similar size. Some rock falls blocked primary and secondary roads, but no other landslide damage was reported. Almost all of the landslides in the peripheral area were small rock falls (∼1–10  m3), but a few larger (∼100  m3) rock slides also occurred. Though there are only informal reports about ground failure in the immediate epicentral area and we lack a detailed survey there, the small number (hundreds) and size of the landslides still seems to be far below global averages for M 7.1. This could be a result of the arid landscape and lack of a deeply weathered zone of soil and regolith. Liquefaction occurred along part of the western margin of Searles Valley. One large (∼0.4  km2) lateral spread caused by liquefaction severely damaged parts of Trona. Minor liquefaction also occurred in a ∼100-m-wide band along the fault-rupture zone in some places.

Effect of Focusing Status on Dimension Measurement Accuracy in Micro Measurement System Based on CCD

2008 ◽  
Vol 392-394 ◽  
pp. 435-438
Author(s):  
Hua Guo ◽  
L. Bai ◽  
J. Liu ◽  
Y. Shi
Keyword(s):  
Measurement System ◽  
Measurement Accuracy ◽  
Experimental Result ◽  
Evaluation Function ◽  
Dimension Measurement ◽  
Special Software ◽  
Institute Of Technology ◽  
Relationship Of ◽  
The Relationship ◽  
Automatic Focusing

This paper adopted the photoelectric micro measurement system based on CCD which was independently developed by Laboratory of Process Automatic and Detection Harbin Institute of Technology to detect dimension of the small precise parts. Under the various focusing status, it was discovered that articulation of focusing has huge effect on the measurement of measurand. According to the characteristics of measurand, we adopted the entropy function as the evaluation function of automatic focusing, developed a special software to process entropy value of the picked images, and obtained the relationship of focusing evaluation function and measurement error through a large number of experiments. The experimental result effectively verified the effect of articulation of focusing on dimension measurement.

scholarly journals CO2 Transport, Variability, and Budget over the Southern California Air Basin Using the High-Resolution WRF-VPRM Model during the CalNex 2010 Campaign

2018 ◽  
Vol 57 (6) ◽  
pp. 1337-1352 ◽  
Author(s):  
Changhyoun Park ◽  
Christoph Gerbig ◽  
Sally Newman ◽  
Ravan Ahmadov ◽  
Sha Feng ◽  
...  
Keyword(s):  
Los Angeles ◽  
Southern California ◽  
Regional Scale ◽  
Wrf Model ◽  
Net Ecosystem Exchange ◽  
Weather Research And Forecasting ◽  
California Institute Of Technology ◽  
Vegetation Class ◽  
Institute Of Technology ◽  
Photosynthesis And Respiration

AbstractTo study regional-scale carbon dioxide (CO2) transport, temporal variability, and budget over the Southern California Air Basin (SoCAB) during the California Research at the Nexus of Air Quality and Climate Change (CalNex) 2010 campaign period, a model that couples the Weather Research and Forecasting (WRF) Model with the Vegetation Photosynthesis and Respiration Model (VPRM) has been used. Our numerical simulations use anthropogenic CO2 emissions of the Hestia Project 2010 fossil-fuel CO2 emissions data products along with optimized VPRM parameters at “FLUXNET” sites, for biospheric CO2 fluxes over SoCAB. The simulated meteorological conditions have been validated with ground and aircraft observations, as well as with background CO2 concentrations from the coastal Palos Verdes site. The model captures the temporal pattern of CO2 concentrations at the ground site at the California Institute of Technology in Pasadena, but it overestimates the magnitude in early daytime. Analysis of CO2 by wind directions reveals the overestimate is due to advection from the south and southwest, where downtown Los Angeles is located. The model also captures the vertical profile of CO2 concentrations along with the flight tracks. The optimized VPRM parameters have significantly improved simulated net ecosystem exchange at each vegetation-class site and thus the regional CO2 budget. The total biospheric contribution ranges approximately from −24% to −20% (daytime) of the total anthropogenic CO2 emissions during the study period.

Is Coca Paste Currently a Drug of Abuse among High School Students?

1981 ◽  
Vol 11 (3) ◽  
pp. 205-212
Author(s):  
George J. Huba ◽  
Marilyn S. Alkin ◽  
Peter M. Bentler
Keyword(s):  
High School ◽  
High School Students ◽  
Longitudinal Study ◽  
Los Angeles ◽  
Drug Use ◽  
School Students ◽  
Drug Of Abuse ◽  
Twelfth Grade ◽  
Relationship Of ◽  
The Relationship

During the spring of 1980 we included items about the use of coca paste in an ongoing longitudinal study of high school students in greater Los Angeles. Of 228 eleventh and twelfth grade males, four (1.8%) claimed to have used coca paste in the previous six months. Of 460 eleventh and twelfth grade females, five (1.1%) reported using coca paste during the six month period. We examine the usage rates in relationship to those for other drugs like liquor, marijuana, PCP, and cocaine. We also studied the relationship of the knowledge of coca paste, having friends who use the drug, and attitudes about the substance to other forms of drug use.

Booker T. Washington Goes West

2016 ◽  
Author(s):  
Marne L. Campbell
Keyword(s):  
African American ◽  
Los Angeles ◽  
The West ◽  
Late 19Th Century ◽  
Local Leadership ◽  
Black Experience ◽  
Relative Gains ◽  
African American Leaders ◽  
Relationship Of ◽  
The Relationship

Finally, Chapter 6, “Mr.Washington Goes West,” examines the two visits by Booker T. Washington, first in 1903, and again in 1914 and investigates whether his national platform was something Black Angelenos wanted for their community, given the relative gains they made during the late 19th century. This chapter also considers the Washington’s relationship with the local leadership while drawing comparisons with Du Bois’s role in early Black Los Angeles history. This chapter also places the black experience in the West within the context of the national experience by considering the relationship of these two African American leaders with Black Angelenos.

Abstract 5025: Transition to Menopause and Preclinical Atherosclerosis in Women: A Report from the Los Angeles Atherosclerosis Study (LAAS)

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
B Delia Johnson ◽  
Kathleen Dwyer ◽  
Maura Paul-Labrador ◽  
Frank Stanczyk ◽  
Vera Bittner ◽  
...  
Keyword(s):  
Los Angeles ◽  
Menopausal Status ◽  
Menopausal Transition ◽  
Progression Rate ◽  
Atherosclerosis Progression ◽  
Edge Tracking ◽  
Rate Of Progression ◽  
Relationship Of ◽  
The Relationship ◽  
Preclinical Atherosclerosis

While the relation between the onset of menopause and accelerated cardiovascular risk has been extensively studied, little information exists on the relationship of the menopausal transition and the development of preclinical atherosclerosis in women. We hypothesized that transition to menopause would be associated with a higher rate of progression of preclinical atherosclerosis. Methods: We evaluated 203 women (131 postmenopausal, 20 perimenopausal, and 52 premenopausal at entry) undergoing carotid intimal-media thickness (cIMT) measurement in the LAAS study, a prospective cohort study that included women aged 45– 60 years at entry without diagnosed cardiovascular disease who underwent three measurements (baseline, 1.5 and 3 year followup). cIMT was measured bilaterally in two body positions (lateral and supine), and average thickness over a 1 cm segment of the distal wall 25 mm proximal to the bulb was measured using automated edge-tracking software. Results: The mean age was 52±4 years, mean body mass index was 27.2±5.8, and 49% were non-white. At entry, 53% had hypertension, 3% diabetes, 16% were current smokers. Age-adjusted cIMT progression rate was similar among pre-, peri- and postmenopausal women (9±15 μ/yr) at entry, and similar among women who remained premenopausal (n=21) compared to those that transitioned to menopause (n=51) and to those who remained postmenopausal (n=131) during the observation period. Of the 51 transitioning women, age was not related to rate of cIMT progression. However, the rapidity of menopausal transition was related to the rate of IMT progression: women transitioning from pre to postmenopause within the 3 year period had a higher rate of cIMT progression compared to women with a slower transition (progressing from pre- to perimenopause, or from peri- to postmenopause, p=0.03). Additional adjustment of these results for systolic blood pressure and BMI did not alter the results. Conclusions: Among women undergoing repeated cIMT measurement in the LAAS, a more rapid menopausal transition (from pre- to postmenopause within 3 years) was associated with a higher rate of preclinical atherosclerosis progression; alternatively, menopausal status itself did not appear to be associated with rate of progression.

Carolyn Hove

2020 ◽  
pp. 73-85
Author(s):  
Michele Fiala
Keyword(s):  
Los Angeles ◽  
Early Life ◽  
English Horn ◽  
Relationship Of ◽  
The Relationship

Carolyn Hove has been the solo English horn player in the Los Angeles Philharmonic since 1988. This chapter contains information on her early life and career, becoming an English horn player, and her teaching. She also shares her ideas on vibrato, fundamentals, and the differences between oboe and English horn. She discusses wellness and the relationship of exercise to performance. She talks about her most memorable performances, artists who inspire her, and ensemble skills.

scholarly journals The Relationship of Menopausal Status and Rapid Menopausal Transition with Carotid Intima-Media Thickness Progression in Women: A Report from the Los Angeles Atherosclerosis Study

2010 ◽  
Vol 95 (9) ◽  
pp. 4432-4440 ◽  
Author(s):  
B. Delia Johnson ◽  
Kathleen M. Dwyer ◽  
Frank Z. Stanczyk ◽  
Vera Bittner ◽  
Sarah L. Berga ◽  
...  
Keyword(s):  
Los Angeles ◽  
Menopausal Status ◽  
Intima Media Thickness ◽  
Carotid Intima Media Thickness ◽  
Repeated Measurements ◽  
Menopausal Transition ◽  
Community Based ◽  
Media Thickness ◽  
Relationship Of ◽  
The Relationship

Context: The onset of menopause has been associated with an increase in cardiovascular risk factors. However, little information is available about the rapidity of the menopausal transition and its relationship to the development of preclinical cardiovascular disease (CVD). Objective: Our objective was to assess whether the rate of carotid intima-media thickness (cIMT) progression over time differs according to 1) menopausal status and 2) rapidity of the menopausal transition. Design: We evaluated 203 community-based women aged 45–60 yr without previously diagnosed CVD who underwent three repeated measurements of cIMT as a measure of preclinical CVD over 3 yr. Menopausal status was ascertained at each visit based on menstrual cycle parameters and reproductive hormone profiles. Of these, 21 remained premenopausal, 51 transitioned, and 131 were postmenopausal throughout the observation period. Results: Age-adjusted cIMT progression rates were similar among premenopausal, transitioning, and postmenopausal women. In the 51 transitioning women, age was not related to rate of cIMT progression. However, the rapidity of menopausal transition was related to cIMT progression: women transitioning from pre- to postmenopause within the 3-yr period had a higher rate of cIMT progression compared with women with a slower transition. Statistical adjustments for the significant covariates of systolic blood pressure, body mass index, race, cigarette smoking, or hormone therapy use did not alter the findings. Conclusions: Among healthy women undergoing repeated cIMT measurement, a more rapid menopausal transition was associated with a higher rate of preclinical CVD progression measured by cIMT. Further work is needed to explore potential mechanisms of this effect.

scholarly journals Toward an Infrastructural Sublime: Narrating Interdependency in Karen Tei Yamashita’s Los Angeles

MELUS ◽  
2020 ◽  
Vol 45 (2) ◽  
pp. 1-24
Author(s):  
Jina B Kim
Keyword(s):  
Los Angeles ◽  
American Literature ◽  
Public Infrastructure ◽  
Aesthetic Value ◽  
The Public ◽  
Self Sufficiency ◽  
Distribution Of Resources ◽  
Labor Networks ◽  
Relationship Of ◽  
The Relationship

Abstract This article examines the vibrant city infrastructures of Karen Tei Yamashita's 1997 novel Tropic of Orange in order to highlight interdependency as political and aesthetic value. The novel's emphasis on urban support systems—the oft-unnoticed roads, pipes, wires, and labor networks that allow the city to function—positions infrastructure as itself a critical lens, one that can reassess the relationship of ethnic American literature and subjectivity to the values of self-ownership, protest, and independence. By amplifying the overlooked support networks that underpin fictions of self-sufficiency, Yamashita's Tropic of Orange diverges from the narrative of self-ownership as liberatory endpoint. Instead, it recuperates the much-maligned category of dependency, positioning dependency as a vital site of aesthetic and political possibility within anti-racist and anti-capitalist struggle. This recuperation proves particularly significant in light of pernicious and persistent dependency mythologies, such as the “illegal immigrant,” that frame racialized subjects as drains on the public. Infrastructure, as an often unseen entity nonetheless central to the operation of cities and the global distribution of resources, represents a key vehicle in Tropic of Orange for thinking about contemporary ecologies of assistance, power, and provision, and for mapping the global imbalances of power that render certain dependencies hypervisible while erasing others.

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