Near-Field Strong Ground Motions from GPS-Derived Velocities for 2020 Intermountain Western United States Earthquakes

2021 ◽  
Author(s):  
Brendan W. Crowell
Keyword(s):  
United States ◽  
Salt Lake ◽  
Near Field ◽  
Salt Lake City ◽  
Strong Motion ◽  
High Rate ◽  
Western United States ◽  
Peak Ground Velocity ◽  
Strong Positive Correlation ◽  
Owens Valley

Abstract In early 2020, four moderate sized earthquakes occurred in the Intermountain region of the western United States, two M 6.5 events in Challis, Idaho, and Monte Cristo Range, Nevada; an M 5.7 in Magna, Utah, within the Salt Lake City metropolitan area; and an M 5.8 in the Owens Valley of California. Although the Magna and Owens Valley earthquakes were well recorded in the near field with an array of seismic instrumentation, the Challis and Monte Cristo events were not densely recorded. All of the events, however, have reasonable coverage with high rate Global Positioning System (GPS) stations in the near field. Here, I report on strong-motion observations recorded at 19 regional GPS stations at 5 Hz. I compare these observations with seismic recordings where available and ShakeMap estimations of peak ground velocity to find good agreement with a natural-log residual of ±0.5. Furthermore, I compute the correlation between collocated stations and show a strong positive correlation >0.65. This study highlights the utility of high-rate GPS velocity observations to strong-motion seismology.

Horizontal particle velocity and its relation to magnitude in the Western United States

1979 ◽  
Vol 69 (6) ◽  
pp. 2037-2061
Author(s):  
A. F. Espinosa
Keyword(s):  
United States ◽  
Data Base ◽  
San Francisco ◽  
Seismic Waves ◽  
Scaling Law ◽  
Direct Determination ◽  
Strong Motion ◽  
Western United States ◽  
Short Period ◽  
Horizontal Particle

abstract A magnitude (ML) scaling law has been derived from the strong-motion data base of the San Fernando earthquake of February 9, 1971, and the results have been compared with other strong-motion recordings obtained from 62 earthquakes in the Western United States. The relationship derived is ML = 3.21 + 1.35 log10Δ + log10v. An excellent agreement was obtained between the determined ML values in this study and those evaluated by Kanamori and Jennings (1978). This scaling law is applicable to the collected data from 63 earthquakes whose local magnitudes range from about 4.0 to 7.2, recorded at epicentral distances between about 5 to 300 km, and with short-period seismic waves in the range of 0.2 to 3.0 sec. The Long Beach earthquake of 1933, with an ML = 6.3 (PAS) and an ML = 6.43 ± 0.36 as determined by Kanamori and Jennings is in agreement with an ML = 6.49 ± 0.32 obtained in this study. The Imperial Valley earthquake of 1940, with an ML = 6.5 (PAS), compares well with an ML = 6.5 as determined in this study. The Kern County earthquake of 1952, with an ML = 7.2 (BRK), is in fairly good agreement with the ML = 7.0 ± 0.2 obtained in this investigation. This value is significantly lower than the commonly quoted 7.7 value for this event. The San Francisco earthquake of 1957, with an ML = 5.3 (BRK), agrees very well with an ML = 5.3 ± 0.1 as determined in this study. The Parkfield earthquake of 1966 has an ML = 5.8 ± 0.3, which is consistent with the 5.6 (PAS). The procedure developed here is applied to the data base obtained from the Western United States strong-motion recordings. The procedure allows the evaluation of ML for moderate and larger earthquakes from the first integration of the strong-motion accelerograms and allows the direct determination of ML from the scaled amplitudes in a rapid, economical, and accurate manner. It also has allowed for the extension of the trend of the attenuation curve for horizontal particle velocities at distances less than 5 km for different size events.

Mythologizing Memories: A Critique of the Utah Korean War Memorial

2012 ◽  
Vol 34 (1) ◽  
pp. 61-82 ◽  
Author(s):  
Suhi Choi
Keyword(s):  
United States ◽  
Korean War ◽  
Salt Lake ◽  
Salt Lake City ◽  
The United States ◽  
Fiftieth Anniversary ◽  
Collective Memories ◽  
The Korean War ◽  
Lake City

Abstract Since its fiftieth anniversary, memorialization of the Korean War has taken place in towns and cities across the United States. As a case study of this belated memory boom, this essay looks at the Utah Korean War Memorial, erected by local veterans in 2003 at Memory Grove Park, Salt Lake City. Situated in both the local and national contexts of remembrance, the memorial resonates largely with three mythical scripts, with themes of resilience, local pride, and the good war, all of which have allowed veterans to negotiate tensions between individual and collective memories. This case study reveals in particular how the official commemoration of the war has shifted local veterans' rhetorical positions from potential witnesses of subversive realities of the war to uncritical negotiators whose legitimization of the very process of mythologizing memories has ultimately alienated them from their own experiences during and after the war.

scholarly journals Coherence between the Great Salt Lake Level and the Pacific Quasi-Decadal Oscillation

2010 ◽  
Vol 23 (8) ◽  
pp. 2161-2177 ◽  
Author(s):  
Shih-Yu Wang ◽  
Robert R. Gillies ◽  
Jiming Jin ◽  
Lawrence E. Hipps
Keyword(s):  
United States ◽  
Great Basin ◽  
Lake Level ◽  
Salt Lake ◽  
Western United States ◽  
Water Vapor Flux ◽  
Vapor Flux ◽  
The Pacific ◽  
Circulation Patterns ◽  
Precipitation Variation

Abstract The lake level elevation of the Great Salt Lake (GSL), a large closed basin lake in the arid western United States, is characterized by a pronounced quasi-decadal oscillation (QDO). The variation of the GSL elevation is very coherent with the QDO of sea surface temperature anomalies in the tropical central Pacific (also known as the Pacific QDO). However, such coherence denies any direct association between the precipitation in the GSL watershed and the Pacific QDO because, in a given frequency, the precipitation variation always leads the GSL elevation variation. Therefore, the precipitation variation is phase shifted from the Pacific QDO. This study investigates the physical mechanism forming the coherence between the GSL elevation and the Pacific QDO. Pronounced and coherent quasi-decadal signals in precipitation, streamflow, water vapor flux, and drought conditions are found throughout the Great Basin. Recurrent atmospheric circulation patterns develop over the Gulf of Alaska during the warm-to-cool and cool-to-warm transition phases of the Pacific QDO. These circulation patterns modulate the water vapor flux associated with synoptic transient activities over the western United States and, in turn, lead to the QDO in the hydrological cycle of the Great Basin. As the GSL integrates the hydrological responses in the Great Basin, the hydrological QDO is then transferred to the GSL elevation. Because the GSL elevation consistently lags the precipitation by a quarter-phase (about 3 yr in the quasi-decadal time scale), these processes take an average of 6 yr for the GSL elevation to eventually respond to the Pacific QDO. This creates a half-phase delay of the GSL elevation from the Pacific QDO, thereby forming the inverse, yet coherent, relationship between them. Tree-ring reconstructed precipitation records confirm that the quasi-decadal signal in precipitation is a prominent feature in this region.

Geology of Salt Lake City, Utah, United States of America

1990 ◽  
Vol xxvii (4) ◽  
pp. 391-478
Author(s):  
W. R. LUND ◽  
G. E. CHRISTENSON ◽  
K. M. HARTY ◽  
S. HECKER ◽  
G. ATWOOD ◽  
...  
Keyword(s):  
United States ◽  
United States Of America ◽  
Salt Lake ◽  
Salt Lake City ◽  
Lake City

The 18 March 2020 M 5.7 Magna, Utah, Earthquake: Strong-Motion Data and Implications for Seismic Hazard in the Salt Lake Valley

2021 ◽  
Author(s):  
Ivan Wong ◽  
Qimin Wu ◽  
James C. Pechmann
Keyword(s):  
Seismic Hazard ◽  
Fault Zone ◽  
Salt Lake ◽  
Salt Lake City ◽  
Strong Motion ◽  
Ground Shaking ◽  
Fault Segment ◽  
Salt Lake Valley ◽  
Lake City ◽  
Wasatch Fault

Abstract The 2020 oblique normal-faulting M 5.7 Magna mainshock has provided the best dataset of recorded strong ground motions for an earthquake within the Wasatch Front region, Utah, and the larger Basin and Range Province. We performed a preliminary evaluation of the strong motion and broadband data from this earthquake and compared the data with the Next Generation Attenuation - West2 Project (NGA-West2) ground-motion models (GMMs). The highest horizontal peak ground acceleration (PGA) recorded was 0.43g (geometric mean of the two horizontal components) at a station located above the rupture plane at a rupture distance of 8 km. Eleven stations recorded PGAs >0.20g. Most of these stations are located on the deep sedimentary deposits within the Salt Lake Valley, and all are at rupture distances <20  km. The data compare favorably with the NGA-West2 GMMs, although the expected variability was observed. PGAs exceed the GMM predictions at the closest distances for the source model that we used. The area of the strongest ground shaking encompassed the town of Magna, where some of the heaviest damage occurred. A significant implication of the 2020 Magna earthquake for seismic hazards in the Salt Lake Valley arises from the possibility that this earthquake occurred on the Salt Lake City segment of the Wasatch fault. If so, then the dip of this fault segment must decrease with depth to ≤30°–35°, as proposed by Pang et al. (2020)—at least along the northern part of the segment where the earthquake occurred. Because of the lack of information about the subsurface geometry of the Wasatch fault zone, modeling of this fault zone in seismic hazard analyses has assumed a moderate dip of 50°±15°. Assuming a more shallowly dipping fault results in higher estimates of ground shaking in future large earthquakes on this fault. Alternative interpretations of the Magna earthquake are that it occurred (1) on an auxiliary fault within the Wasatch fault zone or (2) on a listric section of the northern Salt Lake City segment that is not representative of the geometry of the whole fault segment.

SOLVENT SNIFFING

PEDIATRICS ◽  
1967 ◽  
Vol 39 (3) ◽  
pp. 451-461
Author(s):  
Edward Press ◽  
Alan K. Done
Keyword(s):  
United States ◽  
Salt Lake ◽  
Salt Lake City ◽  
Detailed Comparison ◽  
The United States ◽  
Toxic Effects ◽  
Behavioral Difficulties ◽  
Sources Of Information ◽  
Volatile Organic ◽  
Lake City

THOUSANDS of adolescents and teen-aged youngsters in many cities throughout the United States and other countries are deliberately inhaling vapors of a wide variety of volatile organic solvents in order to induce repeated states of inebriation. Although the practice itself is not new, its occurrence in epidemic proportions in many areas and the passage of legislation prohibiting the act in many cities and states in the United States have brought the problem into nationwide prominence. Some of the solvents used (such as carbon tetrachloride, trichlorethane, benzene, and acetone) have been implicated in previous industrial exposures as the cause of serious toxic effects, including fatalities. The possibility of similar ill effects from these and other solvents when used in much higher concentrations at shorter, but frequently repeated intervals as currently practiced, is one that has been raised repeatedly. Consequently, the Panel on Household and Economic Chemicals of the American Medical Association's Section on Adverse Reactions (Council on Drugs) invited this appraisal of the problem. Included is an assessment of the potential problem from the standpoints of incidence, acute effects, behavioral difficulties, possible chronic or cumulative toxic effects, and possible remedial measures. SOURCES OF INFORMATION This report summarizes the authors' investigations of the problem over the period of the last several years. In addition, it includes a review of published reports, the results of extensive discussions and correspondence with medical and law enforcement personnel in many areas of the United States, Sweden, and elsewhere. Also direct medical and hospital studies of a sample of habitual sniffers by one of us (A.K.D.) in Salt Lake City, Utah, and a detailed comparison of four other similar studies and a personal experiment on simultaneous electroencephalographic tracings and blood level measurements during inhalation by the other (E.P.).

scholarly journals Higher levels of self-efficacy and readiness for a future career among Spanish-speaking physician assistant students after their volunteer work at a student-run free clinic in the United States

2019 ◽  
Vol 16 ◽  
pp. 27
Author(s):  
Shannon Weaver ◽  
Zainub Hussaini ◽  
Virginia Lynn Valentin ◽  
Samin Panahi ◽  
Sarah Elizabeth Levitt ◽  
...  
Keyword(s):  
United States ◽  
Self Efficacy ◽  
Salt Lake ◽  
Physician Assistant ◽  
Salt Lake City ◽  
The United States ◽  
Free Clinic ◽  
Future Career ◽  
The Usa ◽  
Lake City

Volunteering at a free clinic may influence career choice among health profession students. The purpose of this study was to explore knowledge, skills, attitudes, self-efficacy, interest in future work with the underserved, and interest in primary care among physician assistant (PA) students through an analysis of demographic characteristics of PA students at a student-run free clinic in the United States. Data were collected from 56 PA students through a quantitative survey in October 2018 after their participation at a student-run free clinic in Salt Lake City, Utah, in the intermountain west region of the USA. Out of the 3 sub-scales (attitudes, effect, and readiness), students responded most positively to items exploring the effect of their experiences of volunteering at the free clinic. Students who spoke Spanish showed higher levels of self-efficacy and readiness for a future career than non-Spanish speakers.

Self-reports of prescription opioid abuse and diversion among recreational opioid users in a Canadian and a United States city

2015 ◽  
Vol 11 (6) ◽  
pp. 463 ◽  
Author(s):  
Beatrice Setnik, PhD ◽  
Carl L. Roland, PharmD, MS ◽  
Veeraindar Goli, MD ◽  
Glenn C. Pixton, MS ◽  
Naama Levy-Cooperman, PhD ◽  
...  
Keyword(s):  
United States ◽  
Salt Lake ◽  
Salt Lake City ◽  
The United States ◽  
Opioid Abuse ◽  
Prescription Opioid ◽  
Prescription Opioids ◽  
The Us ◽  
Opioid Users ◽  
Prescription Opioid Abuse

Objective: To explore behaviors related to prescription opioid abuse and diversion in individuals who self-reported past recreational (nonmedical) opioid use.Design: A questionnaire was developed and included in two abuse potential clinical studies conducted in Canada (Toronto, ON, August 2010 to January, 2011) and the United States (Salt Lake City, UT, February-May 2011).Participants: Recreational opioid users.Main outcome measure(s): Self-reported behaviors related to prescription opioid abuse and diversion.Results: The questionnaire was completed by 174 participants in the Canadian study and 80 participants in the US study. Most participants reported that they used prescription opioids for nonmedical purposes a few times a month. Most had taken their first prescription opioid between the ages of 12 and 24 years and the two most common reasons were to treat pain or to feel high/stoned. When asked about specific opioids taken for nonmedical purposes in the past year, oxycodone, acetaminophen with codeine, and morphine were commonly used by both cohorts, whereas hydrocodone use was substantially greater in the US cohort versus the Canadian cohort. Participants reported various tampering methods and routes of administration, with swallowed whole, crushed and snorted, and chewed/crushed and swallowed as the most prevalent. Most participants indicated taking other drugs with prescription opioids to get high, most commonly marijuana and alcohol. The most common sources for obtaining prescription opioids were family/friends. Conclusions: Two cohorts of recreational opioid users from Canada and the United States reported similar experiences with various prescription opioids and indicated a predominance of diversion from family/friends.

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