Noise-Based Monitoring of Spatiotemporal Changes in Crustal Seismic Wavespeed across Southern California

2020 ◽  
Author(s):  
Shujuan Mao ◽  
Albanne Lecointre ◽  
Qingyu Wang ◽  
Robert van der Hilst ◽  
Michel Campillo
Keyword(s):  
Los Angeles ◽  
Travel Time ◽  
Large Scale ◽  
Southern California ◽  
Mechanical Response ◽  
Time Lapse ◽  
Salton Sea ◽  
Coda Wave ◽  
Lag Times ◽  
Pressurized Fluids

<p>Monitoring temporal changes in seismic wavespeed can inform our understanding of the evolution of crustal rocks’ mechanical state caused by perturbations in stress field, damages, and fluids. Furthermore, imaging these time-lapse changes in space can help unravel the response of rocks with different elastic properties. In this study, we analyze the spatiotemporal variations of seismic wavespeed in Southern California from 2007 to 2017. We compute the Green’s functions by daily cross-correlations using ambient noise at over three hundred broadband seismic stations. Instead of calculating simply the linear regressions of travel-time shifts over lag-times, which only resolves homogeneous changes, we scrutinize the variations of travel-time shifts at different lag-times and frequencies using coda-wave sensitivity kernels, in order to probe the spatial distribution of wavespeed changes. The long-term and large-scale analysis allows us to investigate the mechanical response of different crustal materials to various transient processes. As an example we use the 2010 Mw 7.2 El Mayor-Cucapah Earthquake (EMC) and show that large coseismic wavespeed reductions occur in Salton Sea area and the Los Angeles sedimentary basin. In the latter region, the ground motion amplification and high susceptibility of sedimentary materials explain the remote signature of the earthquake. In the Salton Sea region, particularly in the geothermal area with highly pressurized fluids, the non-linear crustal response illustrated by wavespeed changes can be analyzed with regard to the high-level micro-seismicity triggered by EMC.</p>

scholarly journals A Novel Decentralized Game-Theoretic Adaptive Traffic Signal Controller: Large-Scale Testing

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2282 ◽  
Author(s):  
Hossam M. Abdelghaffar ◽  
Hesham A. Rakha
Keyword(s):  
Los Angeles ◽  
Travel Time ◽  
Cycle Length ◽  
Large Scale ◽  
Signalized Intersections ◽  
Traffic Signal ◽  
Nash Bargaining ◽  
Downtown Los Angeles ◽  
Game Theoretic ◽  
Queue Lengths

This paper presents a novel de-centralized flexible phasing scheme, cycle-free, adaptive traffic signal controller using a Nash bargaining game-theoretic framework. The Nash bargaining algorithm optimizes the traffic signal timings at each signalized intersection by modeling each phase as a player in a game, where players cooperate to reach a mutually agreeable outcome. The controller is implemented and tested in the INTEGRATION microscopic traffic assignment and simulation software, comparing its performance to that of a traditional decentralized adaptive cycle length and phase split traffic signal controller and a centralized fully-coordinated adaptive phase split, cycle length, and offset optimization controller. The comparisons are conducted in the town of Blacksburg, Virginia (38 traffic signalized intersections) and in downtown Los Angeles, California (457 signalized intersections). The results for the downtown Blacksburg evaluation show significant network-wide efficiency improvements. Specifically, there is a 23.6 % reduction in travel time, a 37.6 % reduction in queue lengths, and a 10.4 % reduction in CO 2 emissions relative to traditional adaptive traffic signal controllers. In addition, the testing on the downtown Los Angeles network produces a 35.1 % reduction in travel time on the intersection approaches, a 54.7 % reduction in queue lengths, and a 10 % reduction in CO 2 emissions compared to traditional adaptive traffic signal controllers. The results demonstrate significant potential benefits of using the proposed controller over other state-of-the-art centralized and de-centralized adaptive traffic signal controllers on large-scale networks both during uncongested and congested conditions.

Filipino Festivals in Southern California

2021 ◽  
Author(s):  
Mary Talusan
Keyword(s):  
United States ◽  
Los Angeles ◽  
Cultural Values ◽  
Large Scale ◽  
Southern California ◽  
The United States ◽  
The Philippines ◽  
Filipino Americans ◽  
Folk Dance ◽  
Jose Rizal

Filipino festivals (also “Philippine festivals”) in southern California are lively, dynamic events that draw multigenerational and multicultural crowds to enjoy food, partake in traditional games and crafts, buy Filipino pride gear, and watch a variety of acts that showcase the talent and creativity of Filipino Americans. Inclusive of those who identify as immigrant, U.S.-born, and transnational, Filipinos from across the region convene to express pride and promote visibility as an overlooked and marginalized ethnic group in the United States. The first public performances by Filipinos in the United States were in exhibits curated by colonial officials at the St. Louis World’s Fair in 1904 to justify colonization of the Philippines. Presented as an uncivilized people in need of American tutelage, this stereotyping of Filipinos as primitives motivated pensionados or students from the Philippines to represent themselves; they organized Rizal Day starting in 1905, which valorized national Philippine hero José Rizal, in order to highlight their identity as modern, educated people. New immigrants, who were mostly rural, single men from the northern Philippines, arrived in the 1930s and frequented taxi dance halls in which Filipino jazz musicians and dancers flourished. Yet the established Filipino community criticized these venues as places of vice that were lacking in family and traditional cultural values. Philippine folk dances were not prevalent among Filipino Americans until after the Philippine Bayanihan Folk Dance Company appeared on the Ed Sullivan Show in 1958. Due to their influence, Filipino American folk dance troupes were established across the nation, presenting Philippine cultures through stylistically diverse dances such as the Indigenous or Tribal suite, the Muslim or “Moro” suite, and the Maria Clara or Spanish-influenced suite. Folk dance performance became a hallmark of festivals such as the Philippine Folk Festival, which has been held annually in San Diego since 1979 (renamed the Philippine Cultural Arts Festival in 1996). In Los Angeles, the Festival of Philippine Arts and Culture began in 1992, attracting thousands from around the region. These large-scale public Filipino festivals in southern California offer opportunities to gain insight into the variety of ways in which Filipino Americans creatively express a range of experiences, interests, and concerns. While folk dance troupes and traditional music ensembles such as Spanish-influenced rondalla (plucked string instruments) are most visibly tied to representations of Philippine traditions, rappers, DJs, spoken word artists, hip-hop dance crews, R&B singers, and rock bands demonstrate Filipinos’ mastery of American popular forms. With origins in community celebrations since the early 1900s, Filipino festivals of the early 21st century reflect changes and continuities in California’s Filipino communities, which have adapted to internal dynamics, larger societal forces, and engagement with the homeland of the Philippines.

scholarly journals COASTAL ENVIRONMENT AND A NUCLEAR POWER PLANT

1976 ◽  
Vol 1 (15) ◽  
pp. 171
Author(s):  
Ralph A. De la Parra
Keyword(s):  
Power Plant ◽  
Los Angeles ◽  
Coastal Plain ◽  
San Diego ◽  
Large Scale ◽  
Southern California ◽  
Total Current ◽  
Sandy Bottom ◽  
Pressurized Water ◽  
Commercial Operation

Regulatory requirements and social constraints make it necessary to evaluate the environmental effects of a project and to incorporate into the design features to minimize adverse environmental impacts. This paper presents a case history of efforts to meet these requirements for a coastal power plant in southern California, Southern California Edison Company and San Diego Gas & Electric Company are jointly now constructing two additional units to the existing San Onofre Nuclear Generating Station, Being added are Units 2 and 3, The site, about 84 acres (34 ha,), is located within Camp Pendleton, a United States Marine Corps Base, about halfway between San Diego and Los Angeles, Califoria, The site (See Figure 1) is situated on the edge of a narrow coastal plain that extends from the coastline to a range of low hills, two miles inland, that have a maximum elevation of 1,725 feet (525 m) above sea level. The plain terminates at the beach in a line of wave-straightened cliffs, extending 60 to 80 feet (18 to 24m) above a narrow sandy beach. Numerous ravines are cut into the cliffs as a result of erosion by storm runoff from the coastal plain, Oceanographic features at the San Onofre site include a sandy bottom which slopes gradually to a depth of 60 feet (18 m) at about 10,000 feet (3,000 m) offshore. Mean maximum summer surface water temperature is about 73°F (23°C). During the fall and winter the water column is usually thermally homogeneous with a minimum temperature of approximately 56°F (13°C). Ocean currents at the site are chiefly tidally induced, although large scale low velocity circulation patterns are generally present. Very near to the southern California coast, local currents are influenced primarily by a combination of wind, tide, and local topography. The total current is ordinarily the sum of components due to wind, tide, and perhaps large-scale ocean circulations. Speed of the total current measured at San Onofre typically ranges from 0.10 to 1,75 knots, but averages 0.2 knots. San Onofre, Units 2 and 3 are being constructed southeast of, and immediately adjacent to existing Unit 1. Both the existing and the units under construction generate electrical power by using pressurized water nuclear reactors. Unit 1 has a capacity of 450 MWe and began commercial operation in 1968, Units 2 and 3 will each have a rated electrical output of 1,100 MWe. Commercial operation of Unit 2 is scheduled to begin in October 1981, and Unit 3 in January of 1983,

By the Numbers

2014 ◽  
Vol 4 (1) ◽  
pp. 46-53
Author(s):  
David L. Ulin ◽  
Joshua Comer
Keyword(s):  
Los Angeles ◽  
Longitudinal Studies ◽  
San Francisco ◽  
Large Scale ◽  
Southern California ◽  
Corpus Analysis ◽  
Northern California ◽  
Google Books

In this article the authors explore the use of “California,” its translations, and associated phrases in the nine languages collected in the Google Books corpora since 1525. The article graphs the use across time, analyzes the data, and considers some of the reasons behind the peaks and troughs of the usage of “California” and related phrases. For those new to computational corpus analysis, this article introduces the techniques and concepts of corpus analysis, explains the strengths and weaknesses of large-scale, longitudinal studies of language, and describes the specific methods applied in this analysis. Across all languages, the frequency of “California” increases steadily until the late 1990s. The article also examine the use of the notable but infrequently used phrase “California dream.” Visualizations of the analyses accompany the article, as well as additional graphs comparing the use of Los Angeles to San Francisco and Northern California to Southern California since 1800.

The Sunland Grizzly

2014 ◽  
Vol 91 (4) ◽  
pp. 56-63
Author(s):  
Josh Sides
Keyword(s):  
Los Angeles ◽  
Los Angeles County ◽  
Southern California ◽  
Grizzly Bear ◽  
Science And Art ◽  
Founding Director

In 1916, Cornelius Birket Johnson, a Los Angeles fruit farmer, killed the last known grizzly bear in Southern California and the second-to last confirmed grizzly bear in the entire state of California. Johnson was neither a sportsman nor a glory hound; he simply hunted down the animal that had been trampling through his orchard for three nights in a row, feasting on his grape harvest and leaving big enough tracks to make him worry for the safety of his wife and two young daughters. That Johnson’s quarry was a grizzly bear made his pastoral life in Big Tujunga Canyon suddenly very complicated. It also precipitated a quagmire involving a violent Scottish taxidermist, a noted California zoologist, Los Angeles museum administrators, and the pioneering mammalogist and Smithsonian curator Clinton Hart Merriam. As Frank S. Daggett, the founding director of the Los Angeles County Museum of History, Science and Art, wrote in the midst of the controversy: “I do not recollect ever meeting a case where scientists, crooks, and laymen were so inextricably mingled.” The extermination of a species, it turned out, could bring out the worst in people.

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