14 CFR 35.38 - Lightning strike.

Code of Federal Regulations, 2011 CFR

2011-01-01

... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller has...

14 CFR 35.38 - Lightning strike.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller has...

14 CFR 35.38 - Lightning strike.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller has...

14 CFR 35.38 - Lightning strike.

Code of Federal Regulations, 2012 CFR

2012-01-01

... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller has...

14 CFR 35.38 - Lightning strike.

Code of Federal Regulations, 2014 CFR

2014-01-01

... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller has...

Bashful ballerina unveiled: Multipole analysis of the coronal magnetic field

NASA Astrophysics Data System (ADS)

Virtanen, I.; Mursula, K.

2012-12-01

Heliospheric current sheet (HCS) is the continuum of the coronal magnetic equator, dividing the heliospheric magnetic field (HMF) into two sectors (polarities). Because of its wavy structure, the HCS is often called the ballerina skirt. Several studies have proven that the HCS is southward shifted during about three years in the solar declining phase. This persistent phenomenon, called the bashful ballerina, has been verified by geomagnetic indices since 1930s, by OMNI data base since 1960s, by the WSO PFSS model since mid-1970s and by the Ulysses probe measurements during the fast latitude scans in 1994-1995 and 2007. We study here the Wilcox Solar Observatory measurements of the photospheric magnetic field and the PFSS extrapolation of the coronal magnetic field. We show that the quadrupole moment of the photospheric magnetic field, which is important for the HCS asymmetry (bashful ballerina), mainly arises from the difference between northern and southern polar field strengths. According to the WSO data the minimum time quadrupole is mainly due to the difference between the highest northern and southern latitude bins. Related studies imply that the southward shift of the HCS is related to the delayed development of southern coronal holes. We also discuss the suggested connection of the HCS asymmetry to sunspot hemispheric asymmetry.

Hemispheric asymmetry in coronal hole evolution: Cause of the bashful ballerina?

NASA Astrophysics Data System (ADS)

Mursula, K.; Tlatov, A.; Virtanen, I.

2012-12-01

The magnetic hemisphere prevalent in the solar northern hemisphere has been shown to cover a larger area than in the south for about three years in the declining phase of several solar cycles. Correspondingly, the average field intensity is weaker in the northern hemisphere and the heliospheric current sheet (HCS) is shifted southward at these times. This phenomenon, now called the bashful ballerina, has been verified using several databases and methods, including the in situ observations of the heliospheric magnetic field (HMF) at 1 AU by the OMNI data base, at about 2 AU by the Ulysses probe, and at different radial distances by the Voyager 1 and 2 and Pioneer 10 and 11 probes. The Ulysses observations show that the mean southward shift of the HCS was about 2 degrees in the declining phase of both cycle 22 and cycle 23, although the polar strengths were very different between the two cycles. The HMF observations by the Voyager and Pioneer probes show a very consistent structure of HMF sectors and HCS location in the entire heliosphere, and even beyond the termination shock. Moreover, they suggest a systematic difference in the development of northern and southern polar coronal holes. While the northern coronal holes developed very systematically during all the four solar minima since mid-1970s, the evolution of southern coronal holes was less systematic and delayed with respect to the northern hemisphere. This delay in the evolution of southern coronal holes leads to a larger extent of northern coronal holes and a southward shift of the heliospheric current sheet (the bashful ballerina phenomenon) for a few years in the declining phase of the solar cycle. Here we study direct observations of solar coronal holes and verify this difference in the evolution of coronal holes between the two solar hemispheres, which explains the bashful ballerina phenomenon.

A bird strike handbook for base-level managers

NASA Astrophysics Data System (ADS)

Payson, R. P.; Vance, J. D.

1984-09-01

To help develop more awareness about bird strikes and bird strike reduction techniques, this thesis compiled all relevant information through an extensive literature search, review of base-level documents, and personal interviews. The final product--A Bird Strike Handbook for Base-Level Managers--provides information on bird strike statistics, methods to reduce the strike hazards, and means to obtain additional assistance. The handbook is organized for use by six major base agencies: Maintenance, Civil Engineering, Operations, Air Field Management, Safety, and Air Traffic Control. An appendix follows at the end.

Storm hazards '79: F-106B operations summary

NASA Technical Reports Server (NTRS)

Fisher, B. D.; Keyser, G. L., Jr.; Deal, P. L.; Thomas, M. E.; Pitts, F. L.

1980-01-01

Preliminary flight tests with a F-106B aircraft were made on the periphery of isolated thunder cells using weather radar support. In addition to storm hazards correlation research, a direct-strike lightning measurement experiment and an atmospheric chemistry experiment were conducted. Two flights were made to close proximity to lightning generating cumulonimbus clouds; however, no direct lightning strikes were experienced. Although no discernible lightning transients were recorded, many operational techniques were identified and established.

A Study of Aircraft Fire Hazards Related to Natural Electrical Phenomena

NASA Technical Reports Server (NTRS)

Kester, Frank L.; Gerstein, Melvin; Plumer, J. A.

1960-01-01

The problems of natural electrical phenomena as a fire hazard to aircraft are evaluated. Assessment of the hazard is made over the range of low level electrical discharges, such as static sparks, to high level discharges, such as lightning strikes to aircraft. In addition, some fundamental work is presented on the problem of flame propagation in aircraft fuel vent systems. This study consists of a laboratory investigation in five parts: (1) a study of the ignition energies and flame propagation rates of kerosene-air and JP-6-air foams, (2) a study of the rate of flame propagation of n-heptane, n-octane, n-nonane, and n-decane in aircraft vent ducts, (3) a study of the damage to aluminum, titanium, and stainless steel aircraft skin materials by lightning strikes, (4) a study of fuel ignition by lightning strikes to aircraft skins, and (5) a study of lightning induced flame propagation in an aircraft vent system.

The NASA F-106B Storm Hazards Program

NASA Technical Reports Server (NTRS)

Neely, W. R., Jr.; Fisher, B. D.

1983-01-01

During the NASA LRC Storm Hazards Program, 698 thunderstorm precipitations were made from 1980 to 1983 with an F-106B aircraft in order to record direct lightning strike data and the associated flight conditions. It was found that each of the three composite fin caps tested experienced multiple lightning attachments with only minor cosmetic damage. The maximum current level was only 20 ka, which is well below the design standard of 200 ka; however, indications are that the current rate of rise standard has been approached and may be exceeded in a major strike. The peak lightning strike rate occurred at ambient temperatures between -40 and -45 C, while most previously reported strikes have occurred at or near the freezing level. No significant operational difficulties or major aircraft damage resulting from the thunderstorm penetrations have been found.

Direct-strike lightning photographs, swept-flash attachment patterns, and flight conditions for storm hazards 1982

NASA Technical Reports Server (NTRS)

Zaepfel, K. P.; Fisher, B. D.; Ott, M. S.

1985-01-01

As part of the NASA Langley Research Center Storm Hazards Program, 241 thunderstorm penetrations were made in 1982 with an F-106B airplane in order to record direct-strike lightning data and the associated flight conditions. During these penetrations, the airplane received 156 direct lightning strikes; in addition, lightning transient data were recorded from 26 nearby lightning flashes. The tests were conducted within 150 nautical miles of Hampton, Virginia, assisted by ground-based weather-radar guidance from the NASA Wallops Flight Facility. The photographs of the lightning attachments taken from two onboard 16-mm color movie cameras and the associated strike attachment patterns are presented. A table of the flight conditions recorded at the time of each lightning event, and a table in which the data are cross-referenced with the previously published lightning electromagnetic waveform data are included.

29 CFR 1910.144 - Safety color code for marking physical hazards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 5 2010-07-01 2010-07-01 false Safety color code for marking physical hazards. 1910.144... § 1910.144 Safety color code for marking physical hazards. (a) Color identification—(1) Red. Red shall be... basic color for designating caution and for marking physical hazards such as: Striking against...

Lightning attachment patterns and flight conditions for storm hazards, 1980

NASA Technical Reports Server (NTRS)

Fisher, B. D.; Keyser, G. L., Jr.; Deal, P. L.

1982-01-01

As part of the NASA Langley Research Center Storm Hazards Program, 69 thunderstorm pentrations were made in 1980 with an F-106B airplane in order to record direct strike lightning data and the associated flight conditions. Ground based weather radar measurements in conjunction with these penetrations were made by NOAA National Severe Storms Laboratory in Oklahoma and by NASA Wallops Flight Center in Virginia. In 1980, the airplane received 10 direct lightning strikes; in addition, lightning transient data were recorded from 6 nearby flashes. Following each flight, the airplane was thoroughly inspected for evidence of lightning attachment, and the individual lightning attachment points were plotted on isometric projections of the airplane to identify swept flash patterns. This report presents pilot descriptions of the direct strikes to the airplane, shows the strike attachment patterns that were found, and discusses the implications of the patterns with respect to aircraft protection design. The flight conditions are also included. Finally, the lightning strike scenarios for three U.S. Air Force F-106A airplanes which were struck during routine operations are given in the appendix to this paper.

Bashful Ballerina: The asymmetric global solar magnetic field viewed from the heliosphere

NASA Astrophysics Data System (ADS)

Mursula, Kalevi

Long-term observations of the heliospheric magnetic field (HMF) at 1 AU have depicted interesting systematic hemispheric and longitudinal asymmetries that have far-reaching implications for the understanding of solar magnetism. It has been found that the HMF sector of the northern solar hemisphere dominates the observed HMF sector occurrence in the heliosphere for about three years during the late declining to minimum phase of the solar cycle. This leads to a persistent southward shift or coning of the heliospheric current sheet at these times, which has been described by the concept of the bashful ballerina. Measurements of the solar surface fields have verified that, at these times, the average field intensity is smaller and the area larger in the northern than in the southern solar hemisphere. They have also shown that a persistent global quadrupole moment, oppositely oriented with respect to the dipole moment, appears at these times. Long-term observations of the geomagnetic field can yield information on the HMF sector structure in the pre-satellite era, and show that the ballerina was bashful at least since 1930s. In addition to the hemispheric asymmetries, the Sun is systematically asymmetric in longitude. The HMF has persistent active longitudes whose dominance depicts an oscillation with a period of about 3.2 years. Similar flip-flopping is also seen in the longitudinal distribution of sunspots and stellar observations show that this is a general pattern for sun-like cool stars. We describe these phenomena and discuss their theoretical implications.

Bashful Ballerina: The asymmetric global solar magnetic field viewed from the heliosphere

NASA Astrophysics Data System (ADS)

Mursula, K.

2008-05-01

Long-term observations of the heliospheric magnetic field (HMF) at 1 AU have depicted interesting systematic hemispheric and longitudinal asymmetries that have far-reaching implications for the understanding of solar magnetism. It has been found that the HMF sector of the northern solar hemisphere dominates the observed HMF sector occurrence in the heliosphere for about three years during the late declining to minimum phase of the solar cycle. This leads to a persistent southward shift or coning of the heliospheric current sheet at these times, which has been described by the concept of the bashful ballerina. Measurements of the solar surface fields have verified that, at these times, the average field intensity is smaller and the area larger in the northern than in the southern solar hemisphere. They have also shown that a persistent global quadrupole moment, oppositely oriented with respect to the dipole moment, appears at these times. Long-term observations of the geomagnetic field can yield information on the HMF sector structure in the pre- satellite era, and show that the ballerina was bashful at least since 1930s. In addition to the hemispheric asymmetries, the Sun is systematically asymmetric in longitude. The HMF has persistent active longitudes whose dominance depicts an oscillation with a period of about 3.2 years. Similar flip-flopping is also seen in the longitudinal distribution of sunspots and stellar observations show that this is a general pattern for sun-like cool stars. We describe these phenomena and discuss their theoretical implications.

Handbook on Bird Management and Control.

DTIC Science & Technology

1980-03-01

strike hazard ...................... 70 FIGURE 10. Sample application of sharp projections ........ 80 FIGURE 11. Plans for a low profile pigeon trap...particularly with Domestic Pigeons , Starlings, and House Sparrows, can reduce most of the hazards mentioned in this chapter. 4.2. HEALTH HAZARDS 4.2.1...damage, pest bird control, hazardous bird control, bird biology t behavior, altering the concept, altering the situation, exclusion, repulsion, removal

Ranking the risk of wildlife species hazardous to military aircraft

USGS Publications Warehouse

Zakrajsek, E.J.; Bissonette, J.A.

2005-01-01

Collisions between birds and aircraft (birdstrikes) pose a major threat to aviation safety. Different species pose different levels of threat; thus, identification of the most hazardous species can help managers identify the level of hazard and prioritize mitigation efforts. Dolbeer et al. (2000) assessed the hazard posed by birds to civilian aircraft by analyzing data from the Federal Aviation Administration's (FAA) Wildlife Strike Database to rank the hazardous species and species groups. A similar analysis has not been done for the military but would be useful and necessary. Military flight characteristics differ from those of civilian flights. During the period 1985-1998, birdstrikes cost the United States Air Force (USAF) an average of $35 million/year in damage. Using the USAF Birdstrike Database, we selected and evaluated each species or species group by the number of strikes recorded in each of 3 damage categories. We weighted damage categories to reflect extent and cost of damage. The USAF Birdstrike Database contained 25,519 records of wildlife strikes in the United States. During the period 1985-1998, 22 (mean = 1.6/year) Class-A birdstrikes (>$1,000,000 damage, loss of aircraft, loss of life, or permanent total disability) were sustained, accounting for 80% of total monetary losses caused by birds. Vultures (Cathartes aura, Coragyps atratus, Caracara cheriway) were ranked the most hazardous species group (Hazard Index Rank [HIR] = 127) to USAF aircraft, followed by geese (Branta canadensis, Chen caerulescens, HIR = 76), pelicans (Pelecanus erythrorhynchos, P. occidentalis, HIR = 47), and buteos (Buteo sp., HIR = 30). Of the smaller flocking birds, blackbirds and starlings (mostly Agelaius phoeniceus, Euphagus cyanocephalus, Molothrus ater, Sturnus vulgaris, HIR = 46), horned larks (Eremophila alpestris, HIR = 24), and swallows (Families Hirundinidae, Apodidae, HIR = 23) were species groups ranked highest. Coupling these results with local bird census data to adjust hazard rank indices to specific locations can facilitate hazard management and lead to meaningful reductions in hazards and costs associated with birdstrikes.

Stress interaction between subduction earthquakes and forearc strike-slip faults: Modeling and application to the northern Caribbean plate boundary

USGS Publications Warehouse

ten Brink, Uri S.; Lin, J.

2004-01-01

Strike-slip faults in the forearc region of a subduction zone often present significant seismic hazard because of their proximity to population centers. We explore the interaction between thrust events on the subduction interface and strike-slip faults within the forearc region using three-dimensional models of static Coulomb stress change. Model results reveal that subduction earthquakes with slip vectors subparallel to the trench axis enhance the Coulomb stress on strike-slip faults adjacent to the trench but reduce the stress on faults farther back in the forearc region. In contrast, subduction events with slip vectors perpendicular to the trench axis enhance the Coulomb stress on strike-slip faults farther back in the forearc, while reducing the stress adjacent to the trench. A significant contribution to Coulomb stress increase on strike-slip faults in the back region of the forearc comes from "unclamping" of the fault, i.e., reduction in normal stress due to thrust motion on the subduction interface. We argue that although Coulomb stress changes from individual subduction earthquakes are ephemeral, their cumulative effects on the pattern of lithosphere deformation in the forearc region are significant. We use the Coulomb stress models to explain the contrasting deformation pattern between two adjacent segments of the Caribbean subduction zone. Subduction earthquakes with slip vectors nearly perpendicular to the Caribbean trench axis is dominant in the Hispaniola segment, where the strike-slip faults are more than 60 km inland from the trench. In contrast, subduction slip motion is nearly parallel to the Caribbean trench axis along the Puerto Rico segment, where the strike-slip fault is less than 15 km from the trench. This observed jump from a strike-slip fault close to the trench axis in the Puerto Rico segment to the inland faults in Hispaniola is explained by different distributions of Coulomb stress in the forearc region of the two segments, as a result of the change from the nearly trench parallel slip on the Puerto Rico subduction interface to the more perpendicular subduction slip beneath Hispaniola. The observations and modeling suggest that subduction-induced strike-slip seismic hazard to Puerto Rico may be smaller than previously assumed but the hazard to Hispaniola remains high. Copyright 2004 by the American Geophysical Union.

The 2014 update to the National Seismic Hazard Model in California

USGS Publications Warehouse

Powers, Peter; Field, Edward H.

2015-01-01

The 2014 update to the U. S. Geological Survey National Seismic Hazard Model in California introduces a new earthquake rate model and new ground motion models (GMMs) that give rise to numerous changes to seismic hazard throughout the state. The updated earthquake rate model is the third version of the Uniform California Earthquake Rupture Forecast (UCERF3), wherein the rates of all ruptures are determined via a self-consistent inverse methodology. This approach accommodates multifault ruptures and reduces the overprediction of moderate earthquake rates exhibited by the previous model (UCERF2). UCERF3 introduces new faults, changes to slip or moment rates on existing faults, and adaptively smoothed gridded seismicity source models, all of which contribute to significant changes in hazard. New GMMs increase ground motion near large strike-slip faults and reduce hazard over dip-slip faults. The addition of very large strike-slip ruptures and decreased reverse fault rupture rates in UCERF3 further enhances these effects.

NGSANE: a lightweight production informatics framework for high-throughput data analysis.

PubMed

Buske, Fabian A; French, Hugh J; Smith, Martin A; Clark, Susan J; Bauer, Denis C

2014-05-15

The initial steps in the analysis of next-generation sequencing data can be automated by way of software 'pipelines'. However, individual components depreciate rapidly because of the evolving technology and analysis methods, often rendering entire versions of production informatics pipelines obsolete. Constructing pipelines from Linux bash commands enables the use of hot swappable modular components as opposed to the more rigid program call wrapping by higher level languages, as implemented in comparable published pipelining systems. Here we present Next Generation Sequencing ANalysis for Enterprises (NGSANE), a Linux-based, high-performance-computing-enabled framework that minimizes overhead for set up and processing of new projects, yet maintains full flexibility of custom scripting when processing raw sequence data. Ngsane is implemented in bash and publicly available under BSD (3-Clause) licence via GitHub at https://github.com/BauerLab/ngsane. Denis.Bauer@csiro.au Supplementary data are available at Bioinformatics online.

Long dance of the bashful ballerina

NASA Astrophysics Data System (ADS)

Hiltula, T.; Mursula, K.

2006-02-01

In this letter we extend our earlier analysis of the north-south asymmetry of the heliospheric current sheet (HCS) using a recent data set of heliospheric magnetic field (HMF) sector polarities extracted from ground-based magnetic observations. We find that the heliospheric current sheet is similarly southward coned or shifted during the late declining to minimum phase of the solar cycle in the early part of the studied data interval (1926-1955), as earlier found for the more recent solar cycles. Accordingly, the HCS has been southward shifted; that is, the solar ballerina has been bashful at least during the last 80 years. We also discuss solar cycle 19 which presents a period of a very curious behaviour for the HCS with an exceptionally large HMF toward sector dominance in 1957, the year of cycle 19 maximum, and an equally strong HMF away sector dominance in 1960, the time of final solar polarity reversal.

Photospheric and coronal magnetic fields in 1974 - 2015: A comparison of six magnetographs

NASA Astrophysics Data System (ADS)

Virtanen, I. I.; Mursula, K.

2015-12-01

Photospheric magnetic field has been measured since 1950s and digital synoptic data exists since 1970s. We study the long-term development of photospheric and coronal magnetic fields, using Wilcox Solar Observatory (WSO), Mount Wilson, Kitt Peak, Solis, SOHO/MDI and SDO/HMI measurements of the photospheric magnetic field and the the potential field source surface (PFSS) model. We pay particular attention to the occurrence of the hemispheric asymmetry of the coronal field. The solar and heliospheric magnetic fields are systematically north-south asymmetric. The southward shift of the heliospheric current sheet (HCS) (the so-called Bashful ballerina phenomenon) is a persistent pattern, which occurs typically for about three years during the late declining phase of solar cycle. Multipole analysis of the photospheric magnetic field has shown that the Bashful ballerina is mainly due to the g02 quadrupole term, which is oppositely signed to the dipole moment and reflects the larger magnitude of the southern polar field. The six data sets are in general in a good agreement with each other, but the different spatial resolution causes difference some in results. Moreover, there are number of deviations in different individual data sets that are not related to resolution, e.g., in WSO data and in the current version of Kitt Peak 512 channel magnetograph data. We note that the two lowest harmonic coefficients do not scale with the overall magnitude of photospheric synoptic magnetic maps. Scaling factors based on histogram techniques can be as large as 10 (from Wilcox to HMI), but the corresponding factor in dipole strength is typically less than two. Scaling also depends on the harmonic coefficient. This should be noted, e.g., when using synoptic maps as input for coronal models. We find that, despite the differences between the six different data sets, especially in the measurements at the highest latitudes, they all support the southward shift of the HCS. At the moment, polar fields have reversed and are strengthening especially in the southern hemisphere, leading to the bashful ballerina, but it is not necessary the final condition during the solar minimum after solar cycle 24. Accordingly, it seems that the Ballerina will be bashful even during cycle 24, although final conclusions must wait the later declining phase.

Hazards in the theater.

PubMed

Rossol, M; Hinkamp, D

2001-01-01

The authors offer a survey of the myriad and unique safety and health hazards faced past and present by performers and theatrical workers, from preproduction work, through the show, and during the strike (dismantling). Special emphasis is given to health hazards posed by the many new plastic resin systems and adhesives used in set, prop, and costume construction; the hazards of special-effect fogs, smokes, haze, dusts, and pyrotechnic emissions; and theatrical makeup.

Evaluating a novel endophytic grass for suppressing invertebrates that contribute to bird strike risk at airports

USDA-ARS?s Scientific Manuscript database

BACKGROUND: Tall fescue containing a selected strain of the fungal endophyte Epichlöe coenophiala purported to express high levels of bioactive alkaloids (Avanex®) was recently commercialized for reducing airport bird strike hazard. We compared bioactivity of Avanex and KY 31, a ubiquitous cultivar...

Dual Fragment Impact of PBX Charges

NASA Astrophysics Data System (ADS)

Haskins, Peter; Briggs, Richard; Leeming, David; White, Nathan; Cheese, Philip; DE&S MoD UK Team; Ordnance Test Solutions Ltd Team

2017-06-01

Fragment impact can pose a significant hazard to many systems containing explosives or propellants. Testing for this threat is most commonly carried out using a single fragment. However, it can be argued that an initial fragment strike (or strikes) could sensitise the energetic material to subsequent impacts, which may then lead to a more violent reaction than would have been predicted based upon single fragment studies. To explore this potential hazard we have developed the capability to launch 2 fragments from the same gun at a range of velocities, and achieve impacts on an acceptor charge with good control over the spatial and temporal separation of the strikes. In this paper we will describe in detail the experimental techniques we have used, both to achieve the dual fragment launch and observe the acceptor charge response. In addition, we will describe the results obtained against PBX filled explosive targets; discuss the mechanisms controlling the target response and their significance for vulnerability assessment. Results of these tests have clearly indicated the potential for detonation upon the second strike, at velocities well below those needed for shock initiation by a single fragment.

The wide skirt of the bashful ballerina: Hemispheric asymmetry of the heliospheric magnetic field in the inner and outer heliosphere

NASA Astrophysics Data System (ADS)

Mursula, K.; Virtanen, I.

2012-04-01

We reanalyze the observations of the heliospheric magnetic field (HMF) made by the Pioneer 10 and 11 and Voyager 1 and 2 heliospheric probes since 1972, and calculate the HMF sector occurrence ratios and tangential component strengths in the different regions of the heliosphere. Observations at the distant probes and at 1 AU show a very consistent picture of the HMF sector structure in the entire heliosphere, and even beyond the termination shock. Pioneer 11 and Voyager 1 show that the development of northern polar coronal holes was very systematic and active during all the four solar minima since mid-1970s. On the other hand, Voyager 2 observations show a less systematic and delayed development of southern coronal holes in 1980s, 1990s and 2000s. This delay in the evolution of southern coronal holes with respect to the rapid and systematic evolution of northern coronal holes leads to a larger extent of northern coronal holes and a southward shift of the heliospheric current sheet (the bashful ballerina phenomenon) for a few years in the late declining phase of each solar cycle. HMF observations of the probes also directly verify the HCS southward shift, supporting earlier observations at 1-2 AU by the Ulysses probe and Earth-orbiting satellites and extending them into the more distant heliosphere. Although the evidence for the connection between the temporal difference in the evolution of polar coronal holes and the bashful ballerina times is based only on three solar cycles, this may be a common pattern for solar coronal hole evolution since the southward shift of the HCS has occurred at least since solar cycle 16.

The wide skirt of the bashful ballerina: Hemispheric asymmetry of the heliospheric magnetic field in the inner and outer heliosphere

NASA Astrophysics Data System (ADS)

Mursula, K.; Virtanen, I. I.

2012-08-01

We reanalyze the observations of the heliospheric magnetic field (HMF) made by the Pioneer 10 and 11 and Voyager 1 and 2 heliospheric probes since 1972, and calculate the HMF sector occurrence ratios and tangential component strengths in the different regions of the heliosphere. Observations at the distant probes and at 1 AU show a very consistent picture of the HMF sector structure in the entire heliosphere, and even beyond the termination shock. HMF observations by the probes also support the southward shift of the heliospheric current sheet (the bashful ballerina phenomenon), which is observed earlier at 1-2 AU by the Ulysses probe and Earth-orbiting satellites, and verify the HCS shift over a wide range of radial distances until the distant heliosphere. Pioneer 11 and Voyager 1 show that the development of northern polar coronal holes was very systematic and active during all the four solar minima since mid-1970s, while Voyager 2 observations show a less systematic and delayed development of southern coronal holes in 1980s, 1990s and 2000s. This delay in the evolution of southern coronal holes with respect to the rapid and systematic evolution of northern coronal holes leads to a larger extent of northern coronal holes and the southward shift of the HCS for a few years in the late declining phase of each solar cycle. Although evidence for the connection between the different evolution of polar coronal holes and the bashful ballerina phenomenon is obtained here only for three solar cycles, this may be a common pattern for solar coronal hole evolution since the southward shift of the HCS has occurred at least since solar cycle 16.

Estimating Bird / Aircraft Collision Probabilities and Risk Utilizing Spatial Poisson Processes

DTIC Science & Technology

2012-06-10

Operations (1995-2011) ........................................... 2 Table 2 DeVault Top 15 Relative Hazard Score...dedicated bird radar (Dokter, et al. 2011). The WRS-88D is used in the Avian Hazard Advisory System which is described later in this paper. Advisory...Avian Hazard Advisory System (AHAS) is an online, near real-time, geographic information system (GIS) used for bird strike risk flight planning across

Installing and Setting Up Git Software Tool on Windows | High-Performance

Science.gov Websites

projects somewhere. In this example, we'll put our work in a "projects" folder inside the " GIT bash options. We'll also assume you'll want to start-off using the GUI. In our example, we've

Academic Success Support Groups.

ERIC Educational Resources Information Center

Halstead, Richard

1998-01-01

Describes a five-week group counseling program designed to help students adopt behaviors that can lead to greater academic success. Phases of the program are (1) institution and professor bashing; (2) member confrontation and accepting responsibility; (3) implementation of success strategies; (4) future pacing. Discusses results and implications.…

Spanish adolescents' attitudes toward transpeople: proposal and validation of a short form of the Genderism and Transphobia Scale.

PubMed

Carrera-Fernández, María Victoria; Lameiras-Fernández, María; Rodríguez-Castro, Yolanda; Vallejo-Medina, Pablo

2014-01-01

The aim of the present study was to develop and validate a short form of the Genderism and Transphobia Scale and assess adolescents' attitudes toward transpeople. A total of 800 Spanish adolescents aged between 14 and 18 years (50.70% girls, 49.30% boys) completed the Spanish version of the scale and other related questionnaires. The short form of the scale is composed of 12 items clustered into two factors (Transphobia/Genderism and Gender Bashing) that explain 54.22% of the variance. All the items showed good discriminating power, and the present scale demonstrated adequate reliability and validity. In the study, boys exhibited significantly more negative attitudes toward transpeople than girls did, both in the affective/cognitive dimension (Transphobia/Genderism) and in the behavioral dimension (Gender Bashing). Moreover, adolescents showed significantly more negative attitudes toward gender-nonconforming men than toward gender-nonconforming women. These results are discussed in terms of their relevance to the maintenance of discriminatory attitudes toward sexual diversity.

Applied Computational Chemistry for the Blind and Visually Impaired

ERIC Educational Resources Information Center

Wedler, Henry B.; Cohen, Sarah R.; Davis, Rebecca L.; Harrison, Jason G.; Siebert, Matthew R.; Willenbring, Dan; Hamann, Christian S.; Shaw, Jared T.; Tantillo, Dean J.

2012-01-01

We describe accommodations that we have made to our applied computational-theoretical chemistry laboratory to provide access for blind and visually impaired students interested in independent investigation of structure-function relationships. Our approach utilizes tactile drawings, molecular model kits, existing software, Bash and Perl scripts…

IQ: Easy to Bash, Hard to Replace.

ERIC Educational Resources Information Center

Pyryt, Michael C.

1996-01-01

This article examines psychometric analysis regarding the viability and limits of IQ testing in the context of "The Bell Curve." It discusses eyeball analysis versus item analysis, mean differences, validity coefficients, general intelligence, and IQ and gifted education, and urges a search for intrapersonal and environmental catalysts…

Lightning swept-stroke attachment patterns and flight conditions for storm hazards 1981

NASA Technical Reports Server (NTRS)

Fisher, B. D.

1984-01-01

As part of the NASA Langley Research Center Storm Hazards Program, 111 thunderstorm penetrations were made in 1981 with an F-106B airplane in order to record direct-strike lightning data and the associated flight conditions. Ground-based weather radar measurements in conjunction with these penetrations were made by NOAA National Severe Storms Laboratory in Oklahoma and by NASA Wallops Flight Facility in Virginia. In 1981, the airplane received 10 direct lightning strikes; in addition, lightning transient data were recorded from 22 nearby flashes. Following each flight, the airplane was thoroughly inspected for evidence of lightning attachment, and the individual lightning attachment points were plotted on isometric projections of the airplane to identify swept-flash patterns. This report shows the strike attachment patterns that were found, and tabulates the flight conditions at the time of each lightning event. Finally, this paper contains a table in which the data in this report are cross-referenced with the previously published electromagnetic waveform data recorded onboard the airplane.

Maintaining Your Passion for the Job

ERIC Educational Resources Information Center

McClellan, George S.

2012-01-01

There are times when passion for a job is seriously tested by the circumstances and conditions of the work. The accumulated effect of long hours, increasing demand for services, shrinking budgets, intractable issues, litigious environments, and what seems at times like incessant bashing of higher education for political purposes can lead to…

Goals 2000: What's in a Name?

ERIC Educational Resources Information Center

Ohanian, Susan

2000-01-01

Goals 2000 is the offspring of "A Nation at Risk," a 1983 teacher- and school-bashing report. IBM CEO Louis Gerstner named the problem and defined the solution, claiming the need for choice, competition, and technology, recasting students as human capital, and marketizing the teacher/community relationship. Tables summarize critics'…

Adult Daughters and Their Mothers: Harmony or Hostility? Working Paper No. 209.

ERIC Educational Resources Information Center

Barnett, Rosalind C.

This paper addresses the mother-daughter relationship from the perspective of adult daughters. The first section focuses on information and myths about adult daughter-older mother relationships, including popular images and assumptions, misunderstandings, taboos, and mother-bashing. The second section describes initial research into the nature of…

The Perennial Trashing of Bourgeois Democracy

ERIC Educational Resources Information Center

Berns, Walter

2002-01-01

What began in nineteenth-century Britain as a serious critique of the new liberal democracy became, in twentieth-century America, a contemptuous "bourgeois bashing," almost a way of life for some of campus radicals. But if not American liberal democracy, with all its vulgarity, then what? What's the alternative? Their intellectuals…

Youth Bashing Gets Old

ERIC Educational Resources Information Center

Ferguson, Christopher J.

2008-01-01

A perennial talking point of politicians and scientists, since the time of the Greeks, is to lament how American youth are sliding into moral decrepitude, lawlessness, and poor mental health. Indeed, to hear some observers talk, particularly in this election year, young people in the United States are being battered by a coarsened culture that…

Environmental Assessment for AFRL/RY Research & Development Activities & Area B Laser Test Area, Wright-Patterson AFB, Ohio

DTIC Science & Technology

2008-10-01

732) 866-2821 Hazards of Electromagnetic Radiation to Ordnance ( HERO ) Mr. Charles Denham/Rick Magrogan Naval Surface Warfare Center, Dahlgren...with a lightning strike; thus the requirements of paragraph C7.4.1 of reference (b) are met. (4) There are no electromagnetic radiation hazards to...the other hazardous material requirements of 49 CFR. This includes, but is not limited to, the packaging, electromagnetic radiation , and

Air traffic controller lightning strike.

PubMed Central

Spieth, M. E.; Kimura, R. L.; Schryer, T. D.

1994-01-01

Andersen Air Force Base in Guam boasts the tallest control tower in the Air Force. In 1986, an air traffic controller was struck by lightning as the bolt proceeded through the tower. Although he received only a backache, the lightning left a hole with surrounding scorch marks on his fatigue shirt and his undershirt. The lightning strike also ignited a portion of the field lighting panel, which caused the runway lights to go out immediately. Lack of a lightning rod is the most likely reason the controller was struck. Proper precautions against lightning strikes can prevent such occupational safety hazards. PMID:7966436

Seismic maps foster landmark legislation

USGS Publications Warehouse

Borcherdt, Roger D.; Brown, Robert B.; Page, Robert A.; Wentworth, Carl M.; Hendley, James W.

1995-01-01

When a powerful earthquake strikes an urban region, damage concentrates not only near the quake's source. Damage can also occur many miles from the source in areas of soft ground. In recent years, scientists have developed ways to identify and map these areas of high seismic hazard. This advance has spurred pioneering legislation to reduce earthquake losses in areas of greatest hazard.

Coping with volcanic hazards; a global perspective

USGS Publications Warehouse

Tilling, R.I.

1990-01-01

Compared to some other natural hazards-such as floods, storms, earthquakes, landslides- volcanic hazards strike infrequently. However, in populated areas , even very small eruptions can wreak havoc and cause widespread devastation. For example, the 13 November 1985 eruption of Nevado del Ruiz in Colombia ejected only about 3 percent of the volume of ash produced during the 18 May 1980 eruption of Mount St. Helens. Yet, the mudflows triggered by this tiny eruption killed more than 25,000 people.

Evidence-Based Practice Empowers Practitioners: A Response to Epstein

ERIC Educational Resources Information Center

Rubin, Allen

2015-01-01

Epstein makes a strong argument for the value of clinical data mining (CDM), although he minimizes some of the potential limitations in that methodology, such as attrition. Epstein's portrayal of evidence-based practice (EBP) as practitioner-bashing and treasuring intervention manuals overlooks the emphasis in the EBP process on the need for…

OHD/HL - National Weather Hydrology Laboratory

Science.gov Websites

resources and services. Design and Programming Standards and Guidelines General Programming C C++ FORTRAN Java v 2.0 updated 3/28/2008 Java v 1.9 Korn and Bash Shell Software Design Phase Guidelines OHD Design Specification Template OHD Design Specification Example Software Peer Review Guidelines and Checklists Software

Nuclear Bashing in Chernobyl Coverage: Fact or Fiction?

ERIC Educational Resources Information Center

Friedman, Sharon M.; And Others

Critics of coverage of nuclear power have charged that the media overemphasize the importance of nuclear accidents, encourage public fear, and omit information vital to public understanding of nuclear power and risk. Some also feel there is an anti-nuclear bias among reporters and editors. A study was conducted to determine if such charges were…

Media Ethics.

ERIC Educational Resources Information Center

Harrison, S. L.

A return to excellence and ethics can end the bashing of the press and earn it respect. H. L. Mencken was an outstanding press-basher. One problem he identified is that journalists see themselves as professionals, when they are no more than "hired hands" unable to control admission to the craft. A solution Mencken offered was to improve…

Bashing Positivism and Reversing a Medical Model under the Guise of Evidence

ERIC Educational Resources Information Center

Wampold, Bruce E.

2003-01-01

In her advocacy of a model to train counseling psychologists as "evidence-based practitioners," Chwalisz (2003) (this issue) criticizes research based on positivism and advocates for methodological pluralism but ironically suggests the adoption of a medical model to influence the discourse on practice. In this comment, the author examines (a)…

The Long History of Labor Bashing

ERIC Educational Resources Information Center

Lichtenstein, Nelson

2011-01-01

When he was still President Obama's chief of staff, Rahm Emanuel, now mayor-elect of Chicago, famously quipped: "Never allow a crisis to go to waste." Republican governors in Wisconsin, New Jersey, Ohio, and other states have certainly taken that advice to heart. By emphasizing, and in some cases manipulating, the red ink flowing through…

All In: Teachers' and College Faculty's Roles in Recruiting Future Physical Educators

ERIC Educational Resources Information Center

Woods, Amelia Mays; Richards, K. Andrew R.; Ayers, Suzan F.

2016-01-01

A 10-year trend of nationwide decreases in teacher preparation enrollments has been notable in physical education teacher education (PETE) programs. Many factors have been offered as an explanation for this drop, including the convenience of online options, a strained economy, political factors, and widespread "teacher bashing." This…

Exploiting Science: Enhancing the Safety Training of Pilots to Reduce the Risk of Bird Strikes

NASA Astrophysics Data System (ADS)

Mendonca, Flavio A. C.

Analysis of bird strikes to aviation in the U.S. from 1990 to 2015 indicate that the successful mitigation efforts at airports, which must be sustained, have reduced incidents with damage and a negative effect-on-flight since 2000. However, such efforts have done little to reduce strikes outside the airport jurisdiction, such as occurred with US Airways Flight 1549 in 2009. There are basically three strategies to mitigate the risk of bird strikes: standards set by aviation authorities, technology, and actions by crewmembers. Pilots play an important role as stakeholders in the prevention of bird strikes, especially outside the airport environment. Thus, safety efforts require enhanced risk management and aeronautical decision-making training for flight crews. The purpose of this study was to determine if a safety training protocol could effectively enhance CFR Part 141 general aviation pilots' knowledge and skills to reduce the risk of bird strikes to aviation. Participants were recruited from the Purdue University professional flight program and from Purdue Aviation. The researcher of this study used a pretest posttest experimental design. Additionally, qualitative data were collected through open-ended questions in the pretest, posttest, and a follow-up survey questionnaire. The participants' pretest and posttest scores were analyzed using parametric and nonparametric tests. Results indicated a significant increase in the posttest scores of the experimental group. An investigation of qualitative data showed that the topic "safety management of bird hazards by pilots" is barely covered during the ground and flight training of pilots. Furthermore, qualitative data suggest a misperception of the safety culture tenets and a poor familiarity with the safety risk management process regarding bird hazards. Finally, the researcher presented recommendations for practice and future research.

The asymmetry of the heliospheric current sheet during solar cycle 23: The last dance of the bashful ballerina?

NASA Astrophysics Data System (ADS)

Mursula, K.; Virtanen, I. I.

2010-05-01

The heliospheric magnetic field has long been hemispherically asymmetric so that the field in the northern hemisphere is weaker and the area larger than in the south. This asymmetry, also called the bashful ballerina, has existed during three-year intervals in the late declining to minimum phase of solar cycles 16-22. We study here the HMF and its hemispheric asymmetry during solar cycle 23. We find that the latitudinal ordering of HMF sectors at low latitudes is exceptional in SC 23: the normal latitudinal variation was not established in the south by Spring 2009, implying that the Rosenberg-Coleman rule is abnormally delayed or broken during this cycle. Comparing the radial field at 1AU and at the coronal source surface footpoint, we show that the HCS was southward shifted even in SC 23 but the shift is considerably smaller than in earlier cycles. We also study the HMF observations during the third perihelion pass of the Ulysses probe in 2007, and find that the northern field was some 0.2 nT stronger than the southern field and that the whole HCS region was clearly shifted southward by about 2°-5°. Accordingly, the north-south asymmetry existed even in SC 23 but was largely masked out in ecliptic observations due to the exceptionally weak polar fields, leading to an abnormally large HCS tilt angle and a wide equatorial belt region. We also note that historical evidence at the ecliptic suggests a connection between solar dipole strength and the size of north-south asymmetry observed there. Based on this, one can predict that, after the present period of weak solar activity started in SC 23, the hemispheric asymmetry will grow again with increasing activity, but the orientation of the asymmetry will be opposite. Thus, after SC 23, the solar ballerina will not be bashful for some 100-150 years.

Wildlife strike risk assessment in several Italian airports: lessons from BRI and a new methodology implementation.

PubMed

Soldatini, Cecilia; Albores-Barajas, Yuri Vladimir; Lovato, Tomas; Andreon, Adriano; Torricelli, Patrizia; Montemaggiori, Alessandro; Corsa, Cosimo; Georgalas, Vyron

2011-01-01

The presence of wildlife in airport areas poses substantial hazards to aviation. Wildlife aircraft collisions (hereafter wildlife strikes) cause losses in terms of human lives and direct monetary losses for the aviation industry. In recent years, wildlife strikes have increased in parallel with air traffic increase and species habituation to anthropic areas. In this paper, we used an ecological approach to wildlife strike risk assessment to eight Italian international airports. The main achievement is a site-specific analysis that avoids flattening wildlife strike events on a large scale while maintaining comparable airport risk assessments. This second version of the Birdstrike Risk Index (BRI2) is a sensitive tool that provides different time scale results allowing appropriate management planning. The methodology applied has been developed in accordance with the Italian Civil Aviation Authority, which recognizes it as a national standard implemented in the advisory circular ENAC APT-01B.

Wildlife Strike Risk Assessment in Several Italian Airports: Lessons from BRI and a New Methodology Implementation

PubMed Central

Soldatini, Cecilia; Albores-Barajas, Yuri Vladimir; Lovato, Tomas; Andreon, Adriano; Torricelli, Patrizia; Montemaggiori, Alessandro; Corsa, Cosimo; Georgalas, Vyron

2011-01-01

The presence of wildlife in airport areas poses substantial hazards to aviation. Wildlife aircraft collisions (hereafter wildlife strikes) cause losses in terms of human lives and direct monetary losses for the aviation industry. In recent years, wildlife strikes have increased in parallel with air traffic increase and species habituation to anthropic areas. In this paper, we used an ecological approach to wildlife strike risk assessment to eight Italian international airports. The main achievement is a site-specific analysis that avoids flattening wildlife strike events on a large scale while maintaining comparable airport risk assessments. This second version of the Birdstrike Risk Index (BRI2) is a sensitive tool that provides different time scale results allowing appropriate management planning. The methodology applied has been developed in accordance with the Italian Civil Aviation Authority, which recognizes it as a national standard implemented in the advisory circular ENAC APT-01B. PMID:22194950

Model of lightning strike to a steel reinforce structure using PSpice

NASA Astrophysics Data System (ADS)

Koone, Neil; Condren, Brian

2003-03-01

Surges and arcs from lightning can pose hazards to personnel and sensitive equipment and processes. Steel reinforcement in structures can act as a Faraday cage mitigating lightning effects. Knowing a structure's response to a lightning strike allows hazards associated with lightning to be analyzed. A model of lightning's response in a steel reinforced structure has been developed using PSpice (a commercial circuit simulation). Segments of rebar are modeled as inductors and resistors in series. A program has been written to take architectural information of a steel reinforced structure and "build" a circuit network that is analogous to the network of reinforcement in a facility. A severe current waveform (simulating a 99th percentile lightning strike), modeled as a current source, is introduced in the circuit network, and potential differences within the structure are determined using PSpice. A visual three-dimensional model of the facility displays the voltage distribution across the structure using color to indicate the potential difference relative to the floor. Clear air arcing distances can be calculated from the voltage distribution using a conservative value for the dielectric breakdown strength of air.

Using exhumation histories to constrain Main Himalayan Thrust geometry and seismic hazard in the western Nepal Himalaya

NASA Astrophysics Data System (ADS)

Harvey, J. E.; Burbank, D.

2016-12-01

The Himalaya of western Nepal present a challenge to conventional understanding of the geometry and behavior of the Main Himalayan Thrust (MHT), a major seismogenic structure which accommodates 2 cm/yr of Indo-Asian convergence. Slip along a steeper ramp in the MHT drives long-term uplift of the Greater Himalaya along >1000 km of the central range front, resulting in a conspicuous physiographic transition known as PT2. This physiographic break is seemingly absent in western Nepal, which suggests a structural geometry and/or kinematic history distinct from areas along strike. This anomaly must be investigated to clarify how seismic hazard may differ from better-understood areas along strike. The importance of this work is heightened by the recent and catastrophic Gorkha earthquake in 2015. We present a suite of 7 relief transects comprising a mix of apatite and zircon U-Th/He and muscovite Ar-Ar cooling ages. These transects were collected across the more gradual mountain front in western Nepal in an effort to clarify where uplift and exhumation have been focused over the past 10 Ma. We invert these cooling ages using the thermo-kinematic model Pecube in order to constrain exhumation histories that best fit the measured cooling ages. Results confirm that MHT geometry and kinematic history in western Nepal are far more complex than in better-studied areas along strike. Exhumation rates in the along-strike projection of PT2 are slow ( 0.1-0.2 km/Myr) compared with rates 50 km toward the hinterland ( 1.0-1.5 km/Myr), suggesting that exhumation has been more rapid in this more northerly position for the past several Ma. Although a range of kinematic scenarios could explain the anomalous cooling histories, it is likely that a recently active midcrustal ramp in the MHT sits beneath this more northerly position. If the 2015 Gorkha earthquake initiated near the up-dip end of the MHT ramp in central Nepal, it is conceivable that similarly hazardous earthquakes could trigger from an analogous structural position in western Nepal, which puts seismic hazard well north of where one would expect by simply projecting PT2 across western Nepal. In addition to clarifying the seismic hazard posed by the MHT to populations in the region, these results are especially relevant to the proposed large hydroelectric dam projects in the region.

Coming of Age, Media and the Mature Audience. Media & Values 45.

ERIC Educational Resources Information Center

Thoman, Elizabeth, Ed.; Silver, Rosalind, Ed.

1989-01-01

This issue of "Media & Values" explores the influence of mass media on the perceptions about aging in our society. The essays present various interpretations of that influence and the implications for the society. Articles in the "Awareness/Analysis" section include: (1) "Granny Bashing: New Myth Recasts Elders as Villains" (Ronald F. Pollack);…

Civility on Campus: Harassment Codes vs. Free Speech. ASHE Annual Meeting Paper.

ERIC Educational Resources Information Center

Nordin, Virginia Davis

In response to the resurgence of racial incidents and increased "gay-bashing" on higher education campuses in recent years, campus authorities have instituted harassment codes thereby giving rise to a conflicts with free speech. Similar conflicts and challenges to free speech have arisen recently in a municipal context such as a St. Paul…

Evaluating lightning hazards to building environments using explicit numerical solutions of Maxwell's equations

NASA Astrophysics Data System (ADS)

Collier, Richard S.; McKenna, Paul M.; Perala, Rodney A.

1991-08-01

The objective here is to describe the lightning hazards to buildings and their internal environments using advanced formulations of Maxwell's Equations. The method described is the Three Dimensional Finite Difference Time Domain Solution. It can be used to solve for the lightning interaction with such structures in three dimensions with the inclusion of a considerable amount of detail. Special techniques were developed for including wire, plumbing, and rebar into the model. Some buildings have provisions for lightning protection in the form of air terminals connected to a ground counterpoise system. It is shown that fields and currents within these structures can be significantly high during a lightning strike. Time lapse video presentations were made showing the electric and magnetic field distributions on selected cross sections of the buildings during a simulated lightning strike.

Evaluating lightning hazards to building environments using explicit numerical solutions of Maxwell's equations

NASA Technical Reports Server (NTRS)

Collier, Richard S.; Mckenna, Paul M.; Perala, Rodney A.

1991-01-01

The objective here is to describe the lightning hazards to buildings and their internal environments using advanced formulations of Maxwell's Equations. The method described is the Three Dimensional Finite Difference Time Domain Solution. It can be used to solve for the lightning interaction with such structures in three dimensions with the inclusion of a considerable amount of detail. Special techniques were developed for including wire, plumbing, and rebar into the model. Some buildings have provisions for lightning protection in the form of air terminals connected to a ground counterpoise system. It is shown that fields and currents within these structures can be significantly high during a lightning strike. Time lapse video presentations were made showing the electric and magnetic field distributions on selected cross sections of the buildings during a simulated lightning strike.

Running Gaussian16 Software Jobs on the Peregrine System | High-Performance

Science.gov Websites

, parallel setup is taken care of automatically based on settings in the PBS script example below. Previous filesystem called /dev/shm. This scratch space is set automatically by the example script below. The Gaussian system. An example script for batch submission is given below. #!/bin/bash #PBS -l nodes=2 #PBS -l

Temporal variations in the position of the heliospheric equator

NASA Astrophysics Data System (ADS)

Obridko, V. N.; Shelting, B. D.

2008-08-01

It is shown that the centroid of the heliospheric equator undergoes quasi-periodic oscillations. During the minimum of the 11-year cycle, the centroid shifts southwards (the so-called bashful-ballerina effect). The direction of the shift reverses during the solar maximum. The solar quadrupole is responsible for this effect. The shift is compared with the tilt of the heliospheric current sheet.

Encore of the Bashful ballerina in solar cycle 23

NASA Astrophysics Data System (ADS)

Mursula, K.; Virtanen, I. I.

2009-04-01

The rotation averaged location of the heliospheric current sheet has been found to be shifted systematically southward for about three years in the late declining to minimum phase of the solar cycle. This behaviour, called by the concept of the Bashful ballerina, has earlier been shown to be valid at least during the active solar cycle of the last century since the late 1920s. Recently, Zhao et al have analysed the WSO observations and conclude that there is no southward coning in HCS or north-south difference in the heliospheric magnetic field during the late declining phase of solar cycle 23. In disagreement with these results, we find that there is a similar but smaller southward shift of the HCS and dominance of the northern field area as in all previous solar cycles. The present smaller asymmetry is in agreement with an earlier observation based on long-term geomagnetic activity that solar hemispheric asymmetry is larger during highly active solar cycles. Moreover, we connect the smallness of shift to the structure of the solar magnetic field with an exceptionally large tilt. We also discuss the cause of the differences between the two approaches reaching different conclusions.

Bashful ballerina: Southward shifted heliospheric current sheet

NASA Astrophysics Data System (ADS)

Mursula, K.; Hiltula, T.

2003-11-01

It is known since long [Rosenberg and Coleman, 1969] that one of the two sectors of the interplanetary magnetic field (IMF) observed at the Earth's orbit dominates at high heliographic latitudes during solar minimum times, reflecting the poloidal structure of the global solar magnetic field at these times. Here we find that while this latitudinal variation of the dominant IMF sector around the solar equator is valid for both solar hemispheres during the last four solar minima covered by direct observations, it is systematically more strongly developed in the northern heliographic hemisphere. This implies that the average heliospheric current sheet is shifted or coned southward during solar minimum times, suggesting that the temporary southward shift of the heliosheet found earlier by Ulysses observations in 1995 is a persistent pattern. This also implies that the open solar magnetic field is north-south asymmetric at these times, suggesting that the solar dynamo has an asymmetric component. Accordingly, the Sun with the heliosheet is like a bashful ballerina who is repeatedly trying to push her excessively high flaring skirt downward. However, the effective shift at 1 AU is only a few degrees, allowing the Rosenberg-Coleman rule to be valid, on an average, in both hemispheres during solar minima.

Bashful Ballerina: Southward shifted Heliospheric Current Sheet

NASA Astrophysics Data System (ADS)

Mursula, K.; Hiltula, T.

It is known since long (Rosenberg and Coleman, 1969) that one of the two sectors of the interplanetary magnetic field (IMF) observed at the Earth's orbit dominates at high heliographic latitudes during solar minimum times, reflecting the poloidal structure of the global solar magnetic field at these times. Here we find that while this latitudinal variation of the dominant IMF sector around the solar equator is valid for both solar hemispheres during the last four solar minima covered by direct observations, it is systematically more strongly developed in the northern heliographic hemisphere. This implies that the average heliospheric current sheet is shifted or coned southward during solar minimum times, suggesting that the temporary southward shift of the heliosheet found earlier by Ulysses observations in 1995 is a persistent pattern. This also implies that the open solar magnetic field is north-south asymmetric at these times, suggesting that the solar dynamo has an asymmetric component. Accordingly, the Sun with the heliosheet is like a bashful ballerina who is repeatedly trying to push her excessively high flaring skirt downward. However, the effective shift at 1 AU is only a few degrees, allowing the Rosenberg-Coleman rule to be valid, on an average, in both hemispheres during solar minima.

PSpice Model of Lightning Strike to a Steel Reinforced Structure

NASA Astrophysics Data System (ADS)

Koone, Neil; Condren, Brian

2003-12-01

Surges and arcs from lightning can pose hazards to personnel and sensitive equipment, and processes. Steel reinforcement in structures can act as a Faraday cage mitigating lightning effects. Knowing a structure's response to a lightning strike allows hazards associated with lightning to be analyzed. A model of lightning's response in a steel reinforced structure has been developed using PSpice (a commercial circuit simulation). Segments of rebar are modeled as inductors and resistors in series. A program has been written to take architectural information of a steel reinforced structure and "build" a circuit network that is analogous to the network of reinforcement in a facility. A severe current waveform (simulating a 99th percentile lightning strike), modeled as a current source, is introduced in the circuit network, and potential differences within the structure are determined using PSpice. A visual three-dimensional model of the facility displays the voltage distribution across the structure using color to indicate the potential difference relative to the floor. Clear air arcing distances can be calculated from the voltage distribution using a conservative value for the dielectric breakdown strength of air. Potential validation tests for the model will be presented.

Research in lightning swept-stroke attachment patterns and flight conditions with the NASA F-106B airplane

NASA Technical Reports Server (NTRS)

Fisher, B. D.; Brown, P. W.; Plumer, J. A.

1985-01-01

Data on 637 direct lightning strikes and 117 close flashes observed by the NASA instrumented F-106B aircraft as part of the Storm Hazards Program at NASA Langley during 1980-1984 are compiled and analyzed, updating the report of Fisher and Plumer (1983). The airborne and ground-based measurement and recording apparatus and the flight and data-reduction procedures are described, and the results are discussed in terms of lightning-strike-conducive flight conditions and lightning attachment patterns. A peak strike rate of 2.1/min is found at altitude 38,000-40,000 ft and temperature below -40 C, with very few strikes below 20,000 ft. Four categories of swept-flash attachment pattern are identified, but it is pointed out that all exterior surfaces of the F-106B are potential attachment sites.

Chemical Safety Alert: Lightning Hazard to Facilities Handling Flammable Substances

EPA Pesticide Factsheets

Raises awareness about lightning strikes, which cause more death/injury and damage than all other environmental elements combined, so industry can take proper precautions to protect equipment and storage or process vessels containing flammable materials.

Who's Bashing Teachers and Public Schools and What Can We Do about It?

ERIC Educational Resources Information Center

Karp, Stan

2011-01-01

The author has spent a large part of his adult life criticizing the flawed institutions and policies of public education as a teacher, an education activist, and a policy advocate. But these days he finds himself spending a lot of time defending the very idea of public education against those who say, sometimes literally, it should be blown up.…

Using the Parallel Computing Toolbox with MATLAB on the Peregrine System |

Science.gov Websites

parallel pool took %g seconds.\\n', toc) % "single program multiple data" spmd fprintf('Worker %d says Hello World!\\n', labindex) end delete(gcp); % close the parallel pool exit To run the script on a compute node, create the file helloWorld.sub: #!/bin/bash #PBS -l walltime=05:00 #PBS -l nodes=1 #PBS -N

Global evaluation of ammonia bidirectional exchange and livestock diurnal variation schemes

EPA Pesticide Factsheets

There is no EPA generated dataset in this study.This dataset is associated with the following publication:Zhu, L., D. Henze, J. Bash , G. Jeong, K. Cady-Pereira, M. Shephard, M. Luo, F. Poulot, and S. Capps. Global evaluation of ammonia bidirectional exchange and livestock diurnal variation schemes. Atmospheric Chemistry and Physics. Copernicus Publications, Katlenburg-Lindau, GERMANY, 15: 12823-12843, (2015).

Structure and mechanics of the Hayward-Rodgers Creek Fault step-over, San Francisco Bay, California

USGS Publications Warehouse

Parsons, T.; Sliter, R.; Geist, E.L.; Jachens, R.C.; Jaffe, B.E.; Foxgrover, A.; Hart, P.E.; McCarthy, J.

2003-01-01

A dilatational step-over between the right-lateral Hayward and Rodgers Creek faults lies beneath San Pablo Bay in the San Francisco Bay area. A key seismic hazard issue is whether an earthquake on one of the faults could rupture through the step-over, enhancing its maximum possible magnitude. If ruptures are terminated at the step-over, then another important issue is how strain transfers through the step. We developed a combined seismic reflection and refraction cross section across south San Pablo Bay and found that the Hayward and Rodgers Creek faults converge to within 4 km of one another near the surface, about 2 km closer than previously thought. Interpretation of potential field data from San Pablo Bay indicated a low likelihood of strike-slip transfer faults connecting the Hayward and Rodgers Creek faults. Numerical simulations suggest that it is possible for a rupture to jump across a 4-km fault gap, although special stressing conditions are probably required (e.g., Harris and Day, 1993, 1999). Slip on the Hayward and Rodgers Creek faults is building an extensional pull-apart basin that could contain hazardous normal faults. We investigated strain in the pull-apart using a finite-element model and calculated a ???0.02-MPa/yr differential stressing rate in the step-over on a least-principal-stress orientation nearly parallel to the strike-slip faults where they overlap. A 1- to 10-MPa stress-drop extensional earthquake is expected on normal faults oriented perpendicular to the strike-slip faults every 50-500 years. The last such earthquake might have been the 1898 M 6.0-6.5 shock in San Pablo Bay that apparently produced a small tsunami. Historical hydrographic surveys gathered before and after 1898 indicate abnormal subsidence of the bay floor within the step-over, possibly related to the earthquake. We used a hydrodynamic model to show that a dip-slip mechanism in north San Pablo Bay is the most likely 1898 rupture scenario to have caused the tsunami. While we find no strike-slip transfer fault between the Hayward and Rodgers Creek faults, a normal-fault link could enable through-going segmented rupture of both strike-slip faults and may pose an independent hazard of M ???6 earthquakes like the 1898 event.

Effectiveness of cable barriers, guardrails, and concrete barrier walls in reducing the risk of injury.

PubMed

Zou, Yaotian; Tarko, Andrew P; Chen, Erdong; Romero, Mario A

2014-11-01

Roadway departure crashes tend to be severe, especially when the roadside exposes the occupants of errant vehicles to excessive injury hazards. As a cost-effective method when the clear zone width is insufficient, road barriers are often installed to prevent errant vehicles from colliding with dangerous obstacles or traversing steep slopes. This paper focuses on the safety performance of road barriers in Indiana in reducing the risk of injury. The objective of the study presented here is to compare the risk of injury among different hazardous events faced by an occupant in a single-vehicle crash. The studied hazardous events include rolling over, striking three types of barriers (guardrails, concrete barrier walls, and cable barriers) with different barrier offsets to the edge of the travelled way, and striking various roadside objects. A total of 2124 single-vehicle crashes (3257 occupants) that occurred between 2008 and 2012 on 517 pair-matched homogeneous barrier and non-barrier segments were analyzed. A binary logistic regression model with mixed effects was estimated for vehicle occupants. The segment pairing process and the use of random effects were able to handle the commonality within the same segment pair as well as the heterogeneity across segment pairs. The modeling results revealed that hitting a barrier is associated with lower risk of injury than a high-hazard event (hitting a pole, rollover, etc.). The odds of injury are reduced by 39% for median concrete barrier walls offset 15-18ft from the travelled way, reduced by 65% for a guardrail face offset 5-55ft, reduced by 85% for near-side median cable barriers (offset between 10ft and 29ft), and reduced by 78% with far-side median cable barriers (offset at least 30ft). Comparing different types of barriers is useful where some types of barriers can be used alternatively. This study found that the odds of injury are 43% lower when striking a guardrail instead of a median concrete barrier offset 15-18ft and 65% lower when striking a median concrete barrier offset 7-14ft. The odds of injury when striking a near-side median cable barrier is 57% lower than the odds for a guardrail face. This reduction for a far side median cable barrier is 37%. Thus, a guardrail should be preferred over a concrete wall and a cable barrier should be preferred over a guardrail where the road and traffic conditions allow. In the light of the results, installing median cable barriers on both sides of the median to reduce their lateral offset is beneficial for safety. The study also found that the unexplained heterogeneity across vehicles is much larger than it was across matched segment pairs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Proceedings of the Annual RAND-China Reform Forum Conference (6th) Held in Beijing, China on August 28-29, 2003

DTIC Science & Technology

2005-01-01

47 “The Status Quo and Prospect of China’s Banking Industry ” by Wang Yuanlong...53 “China’s Financial Sector: Challenges and Repercussions” by K.C. Yeh..69 “Analysis of China’s New Path of Industrialization from a...Path of Industrialization from a Global Perspective” by John Despres..............................................................119 “Bashing China by

MDplot: Visualise Molecular Dynamics.

PubMed

Margreitter, Christian; Oostenbrink, Chris

2017-05-10

The MDplot package provides plotting functions to allow for automated visualisation of molecular dynamics simulation output. It is especially useful in cases where the plot generation is rather tedious due to complex file formats or when a large number of plots are generated. The graphs that are supported range from those which are standard, such as RMsD/RMsF (root-mean-square deviation and root-mean-square fluctuation, respectively) to less standard, such as thermodynamic integration analysis and hydrogen bond monitoring over time. All told, they address many commonly used analyses. In this article, we set out the MDplot package's functions, give examples of the function calls, and show the associated plots. Plotting and data parsing is separated in all cases, i.e. the respective functions can be used independently. Thus, data manipulation and the integration of additional file formats is fairly easy. Currently, the loading functions support GROMOS, GROMACS, and AMBER file formats. Moreover, we also provide a Bash interface that allows simple embedding of MDplot into Bash scripts as the final analysis step. The package can be obtained in the latest major version from CRAN (https://cran.r-project.org/package=MDplot) or in the most recent version from the project's GitHub page at https://github.com/MDplot/MDplot, where feedback is also most welcome. MDplot is published under the GPL-3 license.

Minority stress and sexual problems among African-American gay and bisexual men.

PubMed

Zamboni, Brian D; Crawford, Isiaah

2007-08-01

Minority stress, such as racism and gay bashing, may be associated with sexual problems, but this notion has not been examined in the literature. African-American gay/bisexual men face a unique challenge in managing a double minority status, putting them at high risk for stress and sexual problems. This investigation examined ten predictors of sexual problems among 174 African-American gay/bisexual men. Covarying for age, a forward multiple regression analysis showed that the measures of self-esteem, male gender role stress, HIV prevention self-efficacy, and lifetime experiences with racial discrimination significantly added to the prediction of sexual problems. Gay bashing, psychiatric symptoms, low life satisfaction, and low social support were significantly correlated with sexual problems, but did not add to the prediction of sexual problems in the regression analysis. Mediation analyses showed that stress predicted psychiatric symptoms, which then predicted sexual problems. Sexual problems were not significantly related to HIV status, racial/ethnic identity, or gay identity. The findings from this study showed a relationship between experiences with racial and sexual discrimination and sexual problems while also providing support for mediation to illustrate how stress might cause sexual problems. Addressing minority stress in therapy may help minimize and treat sexual difficulties among minority gay/bisexual men.

Sandy signs of a tsunami's onshore depth and speed

USGS Publications Warehouse

Huntington, K.; Bourgeois, J.; Gelfenbaum, G.; Lynett, P.; Jaffe, B.; Yeh, H.; Weiss, R.

2007-01-01

Tsunamis rank among the most devastating and unpredictable natural hazards to affect coastal areas. Just 3 years ago, in December 2004, the Indian Ocean tsunami caused more than 225,000 deaths. Like many extreme events, however, destructive tsunamis strike rarely enough that written records span too little time to quantify tsunami hazard and risk. Tsunami deposits preserved in the geologic record have been used to extend the record of tsunami occurrence but not the magnitude of past events. To quantify tsunami hazard further, we asked the following question: Can ancient deposits also provide guidance on the expectable water depths and speeds for future tsunamis?

DRAGON ROUGE: The Rescue of Hostages in the Congo

DTIC Science & Technology

1980-01-01

the colonial period. In this study the names in effect in 1964 will be used; however, the initial listings and Map 1 will contain both names. 2 OMMO...recently, in its traditionally skull-bashing manner, against unruly nationalist demonstrators. The perceived loyalty and effectiveness of the Force was... effectiveness of his expanding gendarmerie, he committed the ultimate sin for an African nationalist: he hired white mercenaries. Now, Tshombe was perceived not

Ptolemy Coding Style

DTIC Science & Technology

2014-09-05

shell script that checks Java code and prints out an alphabetical list of unrec- ognized spellings. It properly handles namesWithEmbeddedCapitalization...local/bin/ispell. To run this script, type $PTII/util/testsuite/ptspell *.java • testsuite/chkjava is a shell script for checking various other...best if the svn:native property is set. Below is how to check the values for a file named README.txt: bash-3.2$ svn proplist README.txt Properties on

Sample Batch Scripts for Running Jobs on the Peregrine System |

Science.gov Websites

script for a serial job in the debug queue #!/bin/bash #PBS -lnodes=1:ppn=1,walltime=500 #PBS -N test1 limit #PBS -l nodes=1 # one node #PBS -N test1 # Name of job #PBS -A CSC001 # project handle cd #PBS -q short # short queue #PBS -l nodes=4:ppn=24 # Number of nodes, put 24 processes on each #PBS -N

Validation Test Report for the Automated Optical Processing System (AOPS) Version 4.8

DTIC Science & Technology

2013-06-28

be familiar with UNIX; BASH shell programming; and remote sensing, particularly regarding computer processing of satellite data. The system memory ...and storage requirements are difficult to gauge. The amount of memory needed is dependent upon the amount and type of satellite data you wish to...process; the larger the area, the larger the memory requirement. For example, the entire Atlantic Ocean will require more processing power than the

Spatial Hearing, Attention and Informational Masking in Speech Identification

DTIC Science & Technology

2012-09-12

Midwinter Research Meeting of the Association for Research in Otolaryngology, and at the annual Binaural Bash conference held at Boston University...rather than traditional binaural analysis mechanisms (also related see Best et al., 2005; Allen et al., 2008). The term " binaural analysis" is often...used as a catch-all for any binaural advantage that is not a consequence of simple acoustics (i.e., differential attenuation of sounds at the two

Earthquake hypocenters and focal mechanisms in central Oklahoma reveal a complex system of reactivated subsurface strike-slip faulting

USGS Publications Warehouse

McNamara, Daniel E.; Benz, Harley M.; Herrmann, Robert B.; Bergman, Eric A.; Earle, Paul S.; Holland, Austin F.; Baldwin, Randy W.; Gassner, A.

2015-01-01

The sharp increase in seismicity over a broad region of central Oklahoma has raised concern regarding the source of the activity and its potential hazard to local communities and energy industry infrastructure. Since early 2010, numerous organizations have deployed temporary portable seismic stations in central Oklahoma in order to record the evolving seismicity. In this study, we apply a multiple-event relocation method to produce a catalog of 3,639 central Oklahoma earthquakes from late 2009 through 2014. RMT source parameters were determined for 195 of the largest and best-recorded earthquakes. Combining RMT results with relocated seismicity enabled us to determine the length, depth and style-of-faulting occurring on reactivated subsurface fault systems. Results show that the majority of earthquakes occur on near vertical, optimally oriented (NE-SW and NW-SE), strike-slip faults in the shallow crystalline basement. These are necessary first order observations required to assess the potential hazards of individual faults in Oklahoma.

Fault Imaging with High-Resolution Seismic Reflection for Earthquake Hazard and Geothermal Resource Assessment in Reno, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frary, Roxanna

2012-05-05

The Truckee Meadows basin is situated adjacent to the Sierra Nevada microplate, on the western boundary of the Walker Lane. Being in the transition zone between a range-front normal fault on the west and northwest-striking right-lateral strike slip faults to the east, there is no absence of faulting in this basin. The Reno- Sparks metropolitan area is located in this basin, and with a signi cant population living here, it is important to know where these faults are. High-resolution seismic reflection surveys are used for the imaging of these faults along the Truckee River, across which only one fault wasmore » previously mapped, and in southern Reno near and along Manzanita Lane, where a swarm of short faults has been mapped. The reflection profiles constrain the geometries of these faults, and suggest additional faults not seen before. Used in conjunction with depth to bedrock calculations and gravity measurements, the seismic reflection surveys provide de nitive locations of faults, as well as their orientations. O sets on these faults indicate how active they are, and this in turn has implications for seismic hazard in the area. In addition to seismic hazard, the faults imaged here tell us something about the conduits for geothermal fluid resources in Reno.« less

National athletic trainers' association position statement: lightning safety for athletics and recreation.

PubMed

Walsh, K M; Bennett, B; Cooper, M A; Holle, R L; Kithil, R; López, R E

2000-10-01

To educate athletic trainers and others about the dangers of lightning, provide lightning-safety guidelines, define safe structures and locations, and advocate prehospital care for lightning-strike victims. Lightning may be the most frequently encountered severe-storm hazard endangering physically active people each year. Millions of lightning flashes strike the ground annually in the United States, causing nearly 100 deaths and 400 injuries. Three quarters of all lightning casualties occur between May and September, and nearly four fifths occur between 10:00 AM and 7:00 PM, which coincides with the hours for most athletic or recreational activities. Additionally, lightning casualties from sports and recreational activities have risen alarmingly in recent decades. The National Athletic Trainers' Association recommends a proactive approach to lightning safety, including the implementation of a lightning-safety policy that identifies safe locations for shelter from the lightning hazard. Further components of this policy are monitoring local weather forecasts, designating a weather watcher, and establishing a chain of command. Additionally, a flash-to-bang count of 30 seconds or more should be used as a minimal determinant of when to suspend activities. Waiting 30 minutes or longer after the last flash of lightning or sound of thunder is recommended before athletic or recreational activities are resumed. Lightning- safety strategies include avoiding shelter under trees, avoiding open fields and spaces, and suspending the use of land-line telephones during thunderstorms. Also outlined in this document are the prehospital care guidelines for triaging and treating lightning-strike victims. It is important to evaluate victims quickly for apnea, asystole, hypothermia, shock, fractures, and burns. Cardiopulmonary resuscitation is effective in resuscitating pulseless victims of lightning strike. Maintenance of cardiopulmonary resuscitation and first-aid certification should be required of all persons involved in sports and recreational activities.

Active fault characterization throughout the Caribbean and Central America for seismic hazard modeling

NASA Astrophysics Data System (ADS)

Styron, Richard; Pagani, Marco; Garcia, Julio

2017-04-01

The region encompassing Central America and the Caribbean is tectonically complex, defined by the Caribbean plate's interactions with the North American, South American and Cocos plates. Though active deformation over much of the region has received at least cursory investigation the past 50 years, the area is chronically understudied and lacks a modern, synoptic characterization. Regardless, the level of risk in the region - as dramatically demonstrated by the 2010 Haiti earthquake - remains high because of high-vulnerability buildings and dense urban areas home to over 100 million people, who are concentrated near plate boundaries and other major structures. As part of a broader program to study seismic hazard worldwide, the Global Earthquake Model Foundation is currently working to quantify seismic hazard in the region. To this end, we are compiling a database of active faults throughout the region that will be integrated into similar models as recently done in South America. Our initial compilation hosts about 180 fault traces in the region. The faults show a wide range of characteristics, reflecting the diverse styles of plate boundary and plate-margin deformation observed. Regional deformation ranges from highly localized faulting along well-defined strike-slip faults to broad zones of distributed normal or thrust faulting, and from readily-observable yet slowly-slipping structures to inferred faults with geodetically-measured slip rates >10 mm/yr but essentially no geomorphic expression. Furthermore, primary structures such as the Motagua-Polochic Fault Zone (the strike-slip plate boundary between the North American and Caribbean plates in Guatemala) display strong along-strike slip rate gradients, and many other structures are undersea for most or all of their length. A thorough assessment of seismic hazard in the region will require the integration of a range of datasets and techniques and a comprehensive characterization of epistemic uncertainties driving the overall variability of hazard and risk results. For this reason and in order to leverage from the knowledge available in the region, datasets and the hazard model will be developed in close collaboration with local experts coherently with GEM's principles of transparency and collaboration. For what pertains active faults in shallow crust, we are currently working on assigning slip rates to structures based on geologic and geodetic strain rates, though this will be challenging in areas of sparse constraints. An additional area of ongoing work is the delineation of 3D seismic sources from disjoint fault traces; we are currently evaluating methods for this. Though work in the region is challenging, we anticipate that our results will not only lead to more robust seismic hazard and risk estimates for the region, but may serve as a template for workflows in other zones of poor or inhomogeneous data.

Introduction to Python for CMF Authority Users

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pritchett-Sheats, Lori A.

This talk is a very broad over view of Python that highlights key features in the language used in the Common Model Framework (CMF). I assume that the audience has some programming experience in a shell scripting language (C shell, Bash, PERL) or other high level language (C/C++/ Fortran). The talk will cover Python data types, classes (objects) and basic programming constructs. The talk concludes with slides describing how I developed the basic classes for a TITANS homework assignment.

MDplot: Visualise Molecular Dynamics

PubMed Central

Margreitter, Christian; Oostenbrink, Chris

2017-01-01

The MDplot package provides plotting functions to allow for automated visualisation of molecular dynamics simulation output. It is especially useful in cases where the plot generation is rather tedious due to complex file formats or when a large number of plots are generated. The graphs that are supported range from those which are standard, such as RMsD/RMsF (root-mean-square deviation and root-mean-square fluctuation, respectively) to less standard, such as thermodynamic integration analysis and hydrogen bond monitoring over time. All told, they address many commonly used analyses. In this article, we set out the MDplot package′s functions, give examples of the function calls, and show the associated plots. Plotting and data parsing is separated in all cases, i.e. the respective functions can be used independently. Thus, data manipulation and the integration of additional file formats is fairly easy. Currently, the loading functions support GROMOS, GROMACS, and AMBER file formats. Moreover, we also provide a Bash interface that allows simple embedding of MDplot into Bash scripts as the final analysis step. Availability The package can be obtained in the latest major version from CRAN (https://cran.r-project.org/package=MDplot) or in the most recent version from the project′s GitHub page at https://github.com/MDplot/MDplot, where feedback is also most welcome. MDplot is published under the GPL-3 license. PMID:28845302

Improving tsunami resiliency: California's Tsunami Policy Working Group

USGS Publications Warehouse

Real, Charles R.; Johnson, Laurie; Jones, Lucile M.; Ross, Stephanie L.; Kontar, Y.A.; Santiago-Fandiño, V.; Takahashi, T.

2014-01-01

California has established a Tsunami Policy Working Group to facilitate development of policy recommendations for tsunami hazard mitigation. The Tsunami Policy Working Group brings together government and industry specialists from diverse fields including tsunami, seismic, and flood hazards, local and regional planning, structural engineering, natural hazard policy, and coastal engineering. The group is acting on findings from two parallel efforts: The USGS SAFRR Tsunami Scenario project, a comprehensive impact analysis of a large credible tsunami originating from an M 9.1 earthquake in the Aleutian Islands Subduction Zone striking California’s coastline, and the State’s Tsunami Preparedness and Hazard Mitigation Program. The unique dual-track approach provides a comprehensive assessment of vulnerability and risk within which the policy group can identify gaps and issues in current tsunami hazard mitigation and risk reduction, make recommendations that will help eliminate these impediments, and provide advice that will assist development and implementation of effective tsunami hazard risk communication products to improve community resiliency.

An Evaluation of the Bird/Aircraft Strike Hazard at Hill AFB, Utah (AFLC).

DTIC Science & Technology

1979-01-01

the departure end of Runway 14. During the survey, flocks of Rock Doves ( Columba Livia ) and American Avocets (Recurvjrostra americana) were observed...cyaneus Red—winged Blackbird A~elaius phoeniceusBlack—billed Magpie Pica pica Common Flicker Colaptes auratus Rock Dove Co].umba livia American Avocet

78 FR 23628 - Agency Information Collection Activities; Requests for Comments; Clearance of Renewed Approval of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-19

...In accordance with the Paperwork Reduction Act of 1995, FAA invites public comments about our intention to request the Office of Management and Budget (OMB) approval to renew an information collection. Wildlife strike data are collected to develop standards and monitor hazards to aviation.

Effects of Strike-Slip Fault Segmentation on Earthquake Energy and Seismic Hazard

NASA Astrophysics Data System (ADS)

Madden, E. H.; Cooke, M. L.; Savage, H. M.; McBeck, J.

2014-12-01

Many major strike-slip faults are segmented along strike, including those along plate boundaries in California and Turkey. Failure of distinct fault segments at depth may be the source of multiple pulses of seismic radiation observed for single earthquakes. However, how and when segmentation affects fault behavior and energy release is the basis of many outstanding questions related to the physics of faulting and seismic hazard. These include the probability for a single earthquake to rupture multiple fault segments and the effects of segmentation on earthquake magnitude, radiated seismic energy, and ground motions. Using numerical models, we quantify components of the earthquake energy budget, including the tectonic work acting externally on the system, the energy of internal rock strain, the energy required to overcome fault strength and initiate slip, the energy required to overcome frictional resistance during slip, and the radiated seismic energy. We compare the energy budgets of systems of two en echelon fault segments with various spacing that include both releasing and restraining steps. First, we allow the fault segments to fail simultaneously and capture the effects of segmentation geometry on the earthquake energy budget and on the efficiency with which applied displacement is accommodated. Assuming that higher efficiency correlates with higher probability for a single, larger earthquake, this approach has utility for assessing the seismic hazard of segmented faults. Second, we nucleate slip along a weak portion of one fault segment and let the quasi-static rupture propagate across the system. Allowing fractures to form near faults in these models shows that damage develops within releasing steps and promotes slip along the second fault, while damage develops outside of restraining steps and can prohibit slip along the second fault. Work is consumed in both the propagation of and frictional slip along these new fractures, impacting the energy available for further slip and for subsequent earthquakes. This suite of models reveals that efficiency may be a useful tool for determining the relative seismic hazard of different segmented fault systems, while accounting for coseismic damage zone production is critical in assessing fault interactions and the associated energy budgets of specific systems.

Earthquakes in Hawai‘i—an underappreciated but serious hazard

USGS Publications Warehouse

Okubo, Paul G.; Nakata, Jennifer S.

2011-01-01

The State of Hawaii has a history of damaging earthquakes. Earthquakes in the State are primarily the result of active volcanism and related geologic processes. It is not a question of "if" a devastating quake will strike Hawai‘i but rather "when." Tsunamis generated by both distant and local quakes are also an associated threat and have caused many deaths in the State. The U.S. Geological Survey (USGS) and its cooperators monitor seismic activity in the State and are providing crucial information needed to help better prepare emergency managers and residents of Hawai‘i for the quakes that are certain to strike in the future.

The 2002 Denali fault earthquake, Alaska: A large magnitude, slip-partitioned event

USGS Publications Warehouse

Eberhart-Phillips, D.; Haeussler, Peter J.; Freymueller, J.T.; Frankel, A.D.; Rubin, C.M.; Craw, P.; Ratchkovski, N.A.; Anderson, G.; Carver, G.A.; Crone, A.J.; Dawson, T.E.; Fletcher, H.; Hansen, R.; Harp, E.L.; Harris, R.A.; Hill, D.P.; Hreinsdottir, S.; Jibson, R.W.; Jones, L.M.; Kayen, R.; Keefer, D.K.; Larsen, C.F.; Moran, S.C.; Personius, S.F.; Plafker, G.; Sherrod, B.; Sieh, K.; Sitar, N.; Wallace, W.K.

2003-01-01

The MW (moment magnitude) 7.9 Denali fault earthquake on 3 November 2002 was associated with 340 kilometers of surface rupture and was the largest strike-slip earthquake in North America in almost 150 years. It illuminates earthquake mechanics and hazards of large strike-slip faults. It began with thrusting on the previously unrecognized Susitna Glacier fault, continued with right-slip on the Denali fault, then took a right step and continued with right-slip on the Totschunda fault. There is good correlation between geologically observed and geophysically inferred moment release. The earthquake produced unusually strong distal effects in the rupture propagation direction, including triggered seismicity.

Expansion and Automation of the Energy Conserving Orientational Force for Calculation of Grain Boundary Mobility

DTIC Science & Technology

2018-02-21

change. Approved for public release; distribution is unlimited. 18 A.1 ThermalData.py import numpy import math import os from submit_maker...numpy import math import os from submit_maker import * import time from decimal import * #NOTE: ThermalData.py for the given material and...8217/’+Orientation+’/Submitfiles/submit_excal_’+r epr(temp)+’K_’+repr(u)+’eV.bash’) A.3 submit_maker.py import math import os def

The Prospect of Increased Japanese Military Burdensharing

DTIC Science & Technology

1988-03-30

defense issues, the understanding of Japan’s future will be a key asset in formulating an effective negotiation strategy. 5 I,~ SOME COMMON MISPERCEPTIONS...entire Warsaw Pact nations and the Soviet Union together. 3 A Rand Corporation study also concluded that Asia’s economy will play a larger part in a...military roles in the area, they warfi that Japan will steal our technologies for other uses. Bashing a key friend and ally in this manner is, to say

PARTICLE PHYSICS: CERN Gives Higgs Hunters Extra Month to Collect Data.

PubMed

Morton, O

2000-09-22

After 11 years of banging electrons and positrons together at higher energies than any other machine in the world, CERN, the European laboratory for particle physics, had decided to shut down the Large Electron-Positron collider (LEP) and install a new machine, the Large Hadron Collider (LHC), in its 27-kilometer tunnel. In 2005, the LHC will start bashing protons together at even higher energies. But tantalizing hints of a long-sought fundamental particle have forced CERN managers to grant LEP a month's reprieve.

High tsunami frequency as a result of combined strike-slip faulting and coastal landslides

USGS Publications Warehouse

Hornbach, Matthew J.; Braudy, Nicole; Briggs, Richard W.; Cormier, Marie-Helene; Davis, Marcy B.; Diebold, John B.; Dieudonne, Nicole; Douilly, Roby; Frohlich, Cliff; Gulick, Sean P.S.; Johnson, Harold E.; Mann, Paul; McHugh, Cecilia; Ryan-Mishkin, Katherine; Prentice, Carol S.; Seeber, Leonardo; Sorlien, Christopher C.; Steckler, Michael S.; Symithe, Steeve Julien; Taylor, Frederick W.; Templeton, John

2010-01-01

Earthquakes on strike-slip faults can produce devastating natural hazards. However, because they consist predominantly of lateral motion, these faults are rarely associated with significant uplift or tsunami generation. And although submarine slides can generate tsunami, only a few per cent of all tsunami are believed to be triggered in this way. The 12 January Mw 7.0 Haiti earthquake exhibited primarily strike-slip motion but nevertheless generated a tsunami. Here we present data from a comprehensive field survey that covered the onshore and offshore area around the epicentre to document that modest uplift together with slope failure caused tsunamigenesis. Submarine landslides caused the most severe tsunami locally. Our analysis suggests that slide-generated tsunami occur an order-of-magnitude more frequently along the Gonave microplate than global estimates predict. Uplift was generated because of the earthquake's location, where the Caribbean and Gonave microplates collide obliquely. The earthquake also caused liquefaction at several river deltas that prograde rapidly and are prone to failure. We conclude that coastal strike-slip fault systems such as the Enriquillo-Plantain Garden fault produce relief conducive to rapid sedimentation, erosion and slope failure, so that even modest predominantly strike-slip earthquakes can cause potentially catastrophic slide-generated tsunami - a risk that is underestimated at present.

The effect of directivity in a PSHA framework

NASA Astrophysics Data System (ADS)

Spagnuolo, E.; Herrero, A.; Cultrera, G.

2012-09-01

We propose a method to introduce a refined representation of the ground motion in the framework of the Probabilistic Seismic Hazard Analysis (PSHA). This study is especially oriented to the incorporation of a priori information about source parameters, by focusing on the directivity effect and its influence on seismic hazard maps. Two strategies have been followed. One considers the seismic source as an extended source, and it is valid when the PSHA seismogenetic sources are represented as fault segments. We show that the incorporation of variables related to the directivity effect can lead to variations up to 20 per cent of the hazard level in case of dip-slip faults with uniform distribution of hypocentre location, in terms of spectral acceleration response at 5 s, exceeding probability of 10 per cent in 50 yr. The second one concerns the more general problem of the seismogenetic areas, where each point is a seismogenetic source having the same chance of enucleate a seismic event. In our proposition the point source is associated to the rupture-related parameters, defined using a statistical description. As an example, we consider a source point of an area characterized by strike-slip faulting style. With the introduction of the directivity correction the modulation of the hazard map reaches values up to 100 per cent (for strike-slip, unilateral faults). The introduction of directivity does not increase uniformly the hazard level, but acts more like a redistribution of the estimation that is consistent with the fault orientation. A general increase appears only when no a priori information is available. However, nowadays good a priori knowledge exists on style of faulting, dip and orientation of faults associated to the majority of the seismogenetic zones of the present seismic hazard maps. The percentage of variation obtained is strongly dependent on the type of model chosen to represent analytically the directivity effect. Therefore, it is our aim to emphasize more on the methodology following which, all the information collected may be easily converted to obtain a more comprehensive and meaningful probabilistic seismic hazard formulation.

Health and housing collaboration at LAST: the Philadelphia Lead Abatement Strike Team.

PubMed Central

Campbell, Carla; Himmelsbach, Robert; Palermo, Peter; Tobin, Richard

2005-01-01

The Lead Abatement Strike Team (LAST) was developed in 2002 by the Philadelphia Department of Public Health (PDPH) in response to community concern about management of children with elevated blood lead levels (EBLLs). Fourteen hundred backlog properties (housing at least one child with EBLLs) were identified through inspection as having housing-based lead hazards for which no satisfactory environmental remediation (control of lead hazards) had been achieved. In the first two years of LAST, 834 new housing cases also were identified. The heightened awareness of this problem, sparked in part by community advocacy efforts, led to the appropriation of 1.5 million dollars for environmental remediation. A collaborative group of health, housing, and other officials was convened. Enforcement for remediation of properties with lead hazards was strengthened with the development of the Lead Court, a special judicial court devoted exclusively to hearing cases where owners had violated local lead poisoning prevention laws. Identifying a group of Pennsylvania-certified lead abatement contractors, expanding the health department's abatement team, creating temporary relocation capacity, and providing funding for basic housing system repair work were crucial to obtaining rapid remediation of homes. In the first two years of the LAST program, 1,037 properties (both backlog and new properties) that housed 1,476 children were remediated, representing a significant increase in remediation capacity. PMID:16134560

Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada

NASA Astrophysics Data System (ADS)

Eisses, A.; Kell, A. M.; Kent, G.; Driscoll, N. W.; Karlin, R. E.; Baskin, R. L.; Louie, J. N.; Smith, K. D.; Pullammanappallil, S.

2011-12-01

Preliminary slip rates measured across the East Pyramid Lake fault, or the Lake Range fault, help provide new estimates of extension across the Pyramid Lake basin. Multiple stratigraphic horizons spanning 48 ka were tracked throughout the lake, with layer offsets measured across all significant faults in the basin. A chronstratigraphic framework acquired from four sediment cores allows slip rates of the Lake Range and other faults to be calculated accurately. This region of the northern Walker Lake, strategically placed between the right-lateral strike-slip faults of Honey and Eagle Lakes to the north, and the normal fault bounded basins to the southwest (e.g., Tahoe, Carson), is critical in understanding the underlying structural complexity that is not only necessary for geothermal exploration, but also earthquake hazard assessment due to the proximity of the Reno-Sparks metropolitan area. In addition, our seismic CHIRP imaging with submeter resolution allows the construction of the first fault map of Pyramid Lake. The Lake Range fault can be obviously traced west of Anahoe Island extending north along the east end of the lake in numerous CHIRP lines. Initial drafts of the fault map reveal active transtension through a series of numerous, small, northwest striking, oblique-slip faults in the north end of the lake. A previously field mapped northwest striking fault near Sutcliff can be extended into the west end of Pyramid Lake. This fault map, along with the calculated slip rate of the Lake Range, and potentially multiple other faults, gives a clearer picture into understanding the geothermal potential, tectonic regime and earthquake hazards in the Pyramid Lake basin and the northern Walker Lane. These new results have also been merged with seismicity maps, along with focal mechanisms for the larger events to begin to extend our fault map in depth.

Seismic survey probes urban earthquake hazards in Pacific Northwest

USGS Publications Warehouse

Fisher, M.A.; Brocher, T.M.; Hyndman, R.D.; Trehu, A.M.; Weaver, C.S.; Creager, K.C.; Crosson, R.S.; Parsons, T.; Cooper, A. K.; Mosher, D.; Spence, G.; Zelt, B.C.; Hammer, P.T.; Childs, J. R.; Cochrane, G.R.; Chopra, S.; Walia, R.

1999-01-01

A multidisciplinary seismic survey earlier this year in the Pacific Northwest is expected to reveal much new information about the earthquake threat to U.S. and Canadian urban areas there. A disastrous earthquake is a very real possibility in the region. The survey, known as the Seismic Hazards Investigation in Puget Sound (SHIPS), engendered close cooperation among geologists, biologists, environmental groups, and government agencies. It also succeeded in striking a fine balance between the need to prepare for a great earthquake and the requirement to protect a coveted marine environment while operating a large airgun array.

Food poisoning as an in-flight safety hazard.

PubMed

Beers, K N; Mohler, S R

1985-06-01

The leading cause by far of airline pilot incapacitations is gastrointestinal illness resulting from "food poisoning". This potentially hazardous condition is inadequately dealt with by the airlines today and strikes equally in all pilot age groups. Sufficient incidents are occurring to justify more stringent aircrew meal standards and regulations. Aircrew heart attack and stroke concerns pale into insignificance relative to the far more common food poisoning incapacitations. Specific regulations on aircrew feeding should be promulgated by the Federal Aviation Administration and the regulatory authorities in other countries to preclude simultaneous-onset in-flight incapacitations due to common-source food poisoning.

Rebirth of the Bashful ballerina

NASA Astrophysics Data System (ADS)

Mursula, Kalevi; Virtanen, Ilpo

2016-04-01

Heliospheric current sheet (HCS) is the continuation of the coronal magnetic equator into space, dividing the heliospheric magnetic field (HMF) into two sectors. Because of its wavy structure, the HCS is also called the ballerina skirt. Several recent studies have proven that the HCS is southward shifted during about three years in the solar declining to minimum phase. This persistent phenomenon, now called the Bashful ballerina, has been seen in geomagnetic indices since 1930s, OMNI data since 1960s, WSO data since mid-1970s and in Ulysses probe measurements during the fast latitude scans in 1994-1995 and 2007. Here we study the long-term evolution of photospheric and coronal magnetic fields and the heliospheric current sheet since 1975 using synoptic maps from six observatories (WSO, MWO, Kitt Peak, SOLIS, SOHO/MDI and SDO/HMI). All data sets depict a fairly similar long-term evolution of magnetic fields and the heliospheric current sheet, and agree on the southward shift of the heliospheric current sheet during all the five included cycles. We show that during solar cycles 20 -- 22, the southward shift of the HCS is due to the axial quadrupole term, reflecting the stronger magnetic field intensity at the southern pole during these times. During cycle 23 the asymmetry is less persistent and due to higher harmonics than the quadrupole term. Currently, in the early declining phase of cycle 24, the HCS is also shifted southward and is, again, due to the axial quadrupole, repeating the pattern of most previous cycles.

Bashful ballerina: Multi-instrument verification and recent behaviour

NASA Astrophysics Data System (ADS)

Mursula, Kalevi; Virtanen, Ilpo

2016-07-01

Heliospheric current sheet (HCS) is the continuation of the coronal magnetic equator into space, dividing the heliospheric magnetic field (HMF) into two sectors. Because of its wavy structure, the HCS is also called the ballerina skirt. Several recent studies have proven that the HCS is southward shifted during about three years in the solar declining to minimum phase. This persistent phenomenon, now called the Bashful ballerina, has been seen in geomagnetic indices since 1930s, OMNI data since 1960s, WSO data since mid-1970s and in Ulysses probe measurements during the fast latitude scans in 1994-1995 and 2007. Here we study the long-term evolution of photospheric and coronal magnetic fields and the heliospheric current sheet since 1975 using synoptic maps from six observatories (WSO, MWO, Kitt Peak, SOLIS, SOHO/MDI and SDO/HMI). All data sets depict a fairly similar long-term evolution of magnetic fields and the heliospheric current sheet, and agree on the southward shift of the heliospheric current sheet during all the five included cycles. We show that during solar cycles 20 -- 22, the southward shift of the HCS is due to the axial quadrupole term, reflecting the stronger magnetic field intensity at the southern pole during these times. During cycle 23 the asymmetry is less persistent and due to higher harmonics than the quadrupole term. Currently, in the early declining phase of cycle 24, the HCS is also shifted southward and is, again, due to the axial quadrupole, repeating the pattern of most previous cycles.

Hemispherical and Longitudinal Asymmetries in the Heliospheric Magnetic Field: Flip-flops of a Bashful Ballerina

NASA Astrophysics Data System (ADS)

Hiltula, T.; Mursula, K.

2004-12-01

Several studies during many decennia have studied possible longitudinal and hemispherical asymmetries in various forms of solar activity. E.g., there are well known periods when one of the solar hemispheres has dominated the other in sunspot numbers, flare occurrence or some other form of solar activity. However, the solar asymmetries have not been found to be very conclusive, or to form any clear systematical patterns (e.g., relation to solar cycle). On the contrary, recent studies of similar longitudinal and hemispherical asymmetries in the heliospheric magnetic field have shown a very clear and systematic behaviour. E.g., it was found recently that the dominance of the two HMF sectors experiences an oscillation with a period of about 3.2 years. This new flip-flop periodicity in the heliospheric magnetic field is most likely related to a similar periodicity recently found in sunspots. Also, it has recently been found that the HMF sector coming from the northern solar hemisphere systematically dominates at 1AU during solar minimum times. This leads to a persistent southward shift or coning of the heliospheric current sheet at these times that can be picturesquely described by the concept of a Bashful Ballerina. This result also implies that the Sun has a large-scale quadrupole magnetic moment. Here we review these recent developments concerning the longitudinal and hemispherical asymmetries in the heliospheric magnetic field and study their inter-connection.

The last dance of the bashful ballerina?

NASA Astrophysics Data System (ADS)

Mursula, K.; Virtanen, I.

2011-01-01

Aims: The heliospheric magnetic field (HMF) has long been hemispherically asymmetric so that the field in the northern hemisphere is weaker and the area larger than in the south. This asymmetry, also called the bashful ballerina, has existed during roughly three-year intervals of the late declining to minimum phase of solar cycles 16-22. We study the HMF and its hemispheric asymmetry during the exceptional solar cycle 23. Methods: We use NASA National Space Science Data Center OMNI database, which contains all solar wind and HMF observations at the Earth's orbit, and coronal field predictions by Wilcox Solar Observatory. We present a new method to study the global hemispheric asymmetry by using the power n of the radial decrease of the radial field from the coronal source surface to 1 AU. Results: We find that the HMF is exceptional at low latitudes in solar cycle 23: while the typical latitudinal variation was attained in the north in 2008, it did not take place in the south until Spring 2009. Thus, the Rosenberg-Coleman rule is abnormally delayed or broken for the first time in 50 years. The n-values verify the clear northern dominance in cycles 21-22. However, the low-latitude observations depict a considerably smaller asymmetry in cycle 23, although Ulysses observations at high latitudes show an equally large asymmetry in 2007 and in 1994-1995. We argue that the weak low-latitude visibility of the asymmetry in cycle 23 is due to the exceptionally weak polar fields, leading to large tilt angle and a wide current sheet. Conclusions: We note that the exceptional properties of cycle 23 (weak dynamo, large tilt, small asymmetry) agree with the long-term evolution of hemispheric asymmetry viewed at the Earth. The active Sun is seen as more asymmetric at the Earth than the quiet Sun because the polar coronal holes with unipolar fields extend closer to the equator, allowing their asymmetry to be viewed even at low latitudes. We suggest that, after the period of weak activity and small asymmetry at 1 AU that started with cycle 23, the hemispheric asymmetry will again, with the increasingly active cycles, become better visible at 1 AU but the asymmetry will be oppositely oriented, including a northward shifted current sheet, and larger areas but weaker intensities in the south. Thus, the ballerina should no longer be systematically bashful for some 100-150 years. Figure 4 is only available in electronic form at http://www.aanda.org

The Path to the Professoriate

ERIC Educational Resources Information Center

Diverse: Issues in Higher Education, 2008

2008-01-01

Three letters are known to strike terror into the hearts of all soon-to-be Ph.D.s in English, French, Spanish, Italian and the other languages. They are M, L and A--the acronym for the Modern Language Association, which holds its annual conference and a job fair, whose hazards are legend, every year just days after Christmas. This article…

Effects of lightning on operations of aerospace vehicles

NASA Technical Reports Server (NTRS)

Fisher, Bruce D.

1989-01-01

Traditionally, aircraft lightning strikes were a major aviation safety issue. However, the increasing use of composite materials and the use of digital avionics for flight critical systems will require that more specific lightning protection measures be incorporated in the design of such aircraft in order to maintain the excellent lightning safety record presently enjoyed by transport aircraft. In addition, several recent lightning mishaps, most notably the loss of the Atlas/Centaur-67 vehicle at Cape Canaveral Air Force Station, Florida in March 1987, have shown the susceptibility of aircraft and launch vehicles to the phenomenon of vehicle-triggered lightning. The recent findings of the NASA Storm Hazards Program were reviewed as they pertain to the atmospheric conditions conducive to aircraft lightning strikes. These data are then compared to recent summaries of lightning strikes to operational aircraft fleets. Finally, the new launch commit criteria for triggered lightning being used by NASA and the U.S. Defense Department are summarized. The NASA Research data show that the greatest probability of a direct strike in a thunderstorm occurs at ambient temperatures of about -40 C. Relative precipitation and turbulence levels were characterized as negligible to light for these conditions. However, operational fleet data have shown that most aircraft lightning strikes in routine operations occur at temperatures near the freezing level in non-cumulonimbus clouds. The non-thunderstorm environment was not the subject of dedicated airborne lightning research.

High tsunami frequency as a result of combined strike-slip faulting and coastal landslides

USGS Publications Warehouse

Hornbach, M.J.; Braudy, N.; Briggs, R.W.; Cormier, M.-H.; Davis, M.B.; Diebold, J.B.; Dieudonne, N.; Douilly, R.; Frohlich, C.; Gulick, S.P.S.; Johnson, H. E.; Mann, P.; McHugh, C.; Ryan-Mishkin, K.; Prentice, C.S.; Seeber, L.; Sorlien, C.C.; Steckler, M.S.; Symithe, S.J.; Taylor, F.W.; Templeton, J.

2010-01-01

Earthquakes on strike-slip faults can produce devastating natural hazards. However, because they consist predominantly of lateral motion, these faults are rarely associated with significant uplift or tsunami generation. And although submarine slides can generate tsunami, only a few per cent of all tsunami are believed to be triggered in this way. The 12 January Mw 7.0 Haiti earthquake exhibited primarily strike-slip motion but nevertheless generated a tsunami. Here we present data from a comprehensive field survey that covered the onshore and offshore area around the epicentre to document that modest uplift together with slope failure caused tsunamigenesis. Submarine landslides caused the most severe tsunami locally. Our analysis suggests that slide-generated tsunami occur an order-of-magnitude more frequently along the Gonave microplate than global estimates predict. Uplift was generated because of the earthquake?s location, where the Caribbean and Gonave microplates collide obliquely. The earthquake also caused liquefaction at several river deltas that prograde rapidly and are prone to failure. We conclude that coastal strike-slip fault systems such as the Enriquillog-Plantain Garden fault produce relief conducive to rapid sedimentation, erosion and slope failure, so that even modest predominantly strike-slip earthquakes can cause potentially catastrophic slide-generated tsunamig-a risk that is underestimated at present. ?? 2010 Macmillan Publishers Limited. All rights reserved.

National Athletic Trainers' Association Position Statement: Lightning Safety for Athletics and Recreation

PubMed Central

Walsh, Katie M.; Bennett, Brian; Cooper, Mary Ann; Holle, Ronald L.; Kithil, Richard; López, Raul E.

2000-01-01

Objective: To educate athletic trainers and others about the dangers of lightning, provide lightning-safety guidelines, define safe structures and locations, and advocate prehospital care for lightning-strike victims. Background: Lightning may be the most frequently encountered severe-storm hazard endangering physically active people each year. Millions of lightning flashes strike the ground annually in the United States, causing nearly 100 deaths and 400 injuries. Three quarters of all lightning casualties occur between May and September, and nearly four fifths occur between 10:00 AM and 7:00 PM, which coincides with the hours for most athletic or recreational activities. Additionally, lightning casualties from sports and recreational activities have risen alarmingly in recent decades. Recommendations: The National Athletic Trainers' Association recommends a proactive approach to lightning safety, including the implementation of a lightning-safety policy that identifies safe locations for shelter from the lightning hazard. Further components of this policy are monitoring local weather forecasts, designating a weather watcher, and establishing a chain of command. Additionally, a flash-to-bang count of 30 seconds or more should be used as a minimal determinant of when to suspend activities. Waiting 30 minutes or longer after the last flash of lightning or sound of thunder is recommended before athletic or recreational activities are resumed. Lightning- safety strategies include avoiding shelter under trees, avoiding open fields and spaces, and suspending the use of land-line telephones during thunderstorms. Also outlined in this document are the prehospital care guidelines for triaging and treating lightning-strike victims. It is important to evaluate victims quickly for apnea, asystole, hypothermia, shock, fractures, and burns. Cardiopulmonary resuscitation is effective in resuscitating pulseless victims of lightning strike. Maintenance of cardiopulmonary resuscitation and first-aid certification should be required of all persons involved in sports and recreational activities. PMID:16558665

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, Jonathan R.; Burnett, Damon J.

Sandia National Laboratories operates the Scaled Wind Farm Technology Facility (SWiFT) on behalf of the Department of Energy Wind and Water Power Technologies Office. An analysis was performed to evaluate the hazards associated with debris thrown from one of SWiFT’s operating wind turbines, assuming a catastrophic failure. A Monte Carlo analysis was conducted to assess the complex variable space associated with debris throw hazards that included wind speed, wind direction, azimuth and pitch angles of the blade, and percentage of the blade that was separated. In addition, a set of high fidelity explicit dynamic finite element simulations were performed tomore » determine the threshold impact energy envelope for the turbine control building located on-site. Assuming that all of the layered, independent, passive and active engineered safety systems and administrative procedures failed (a 100% failure rate of the safety systems), the likelihood of the control building being struck was calculated to be less than 5/10,000 and ballistic simulations showed that the control building would not provide passive protection for the majority of impact scenarios. Although options exist to improve the ballistic resistance of the control building, the recommendation is not to pursue them because there is a low probability of strike and there is an equal likelihood personnel could be located at similar distances in other areas of the SWiFT facility which are not passively protected, while the turbines are operating. A fenced exclusion area has been created around the turbines which restricts access to the boundary of the 1/100 strike probability. The overall recommendation is to neither relocate nor improve passive protection of the control building as the turbine safety systems have been improved to have no less than two independent, redundant, high quality engineered safety systems. Considering this, in combination with a control building strike probability of less than 5/10,000, the overall probability of turbine debris striking the control building is less than 1/1,000,000.« less

Final results of the NASA storm hazards program

NASA Technical Reports Server (NTRS)

Fisher, Bruce D.; Brown, Philip W.; Plumer, J. Anderson; Wunschel, Alfred J., Jr.

1988-01-01

Lightning swept-flash attachment patterns and the associated flight conditions were recorded from 1980-1986 during 1496 thunderstorm penetrations and 714 direct strikes with a NASA F-1068 research airplane. These data were studied with an emphasis on lightning avoidance by aircraft and on aircraft protection design. The individual lightning attachment spots, along with crew comments and on-board photographic data were used to identify lightning swept-flash attachment patterns and the orientations of the lightning channels with respect to the airplane. The full-scale in-flight data were compared to results from scale-model arc-attachment tests. The airborne and scale-model data showed that any exterior surface of this airplane may be susceptible to direct lightning attachment. In addition, the altitudes, ambient temperatures, and the relative turbulence and precipitation levels at which the strikes occurred in thunderstorms are summarized and discussed. It was found that the peak strike rate occurred at pressure altitudes betwen 38,000 ft and 40,000 ft, corresponding to ambient temperatures colder than -40 C.

Triggering of destructive earthquakes in El Salvador

NASA Astrophysics Data System (ADS)

Martínez-Díaz, José J.; Álvarez-Gómez, José A.; Benito, Belén; Hernández, Douglas

2004-01-01

We investigate the existence of a mechanism of static stress triggering driven by the interaction of normal faults in the Middle American subduction zone and strike-slip faults in the El Salvador volcanic arc. The local geology points to a large strike-slip fault zone, the El Salvador fault zone, as the source of several destructive earthquakes in El Salvador along the volcanic arc. We modeled the Coulomb failure stress (CFS) change produced by the June 1982 and January 2001 subduction events on planes parallel to the El Salvador fault zone. The results have broad implications for future risk management in the region, as they suggest a causative relationship between the position of the normal-slip events in the subduction zone and the strike-slip events in the volcanic arc. After the February 2001 event, an important area of the El Salvador fault zone was loaded with a positive change in Coulomb failure stress (>0.15 MPa). This scenario must be considered in the seismic hazard assessment studies that will be carried out in this area.

Designing Out the Play: Accessibility and Playfulness in Inclusive Play.

PubMed

Holt, Raymond; Beckett, Angharad

2017-01-01

Play is an important part of child development, yet disabled children are often excluded from the opportunity to play, either due to lack of accessible toys and games, or social pressures. This paper presents a case study reflecting on the development of Button Bash: a switch accessible game intended to encourage inclusive play between disabled and non-disabled children. In particular, the paper focuses on how changes intended to make the game more accessible tended to make it less playful, and reflects on the relationship between playfulness and accessibility.

Commentary on interstellar matter associated with 18 open clusters

NASA Technical Reports Server (NTRS)

Leisawitz, David

1989-01-01

Information supplementary to that contained in Section 4 of an article entitled, A CO Survey of Regions Around 34 Open Clusters, (Leisawitz, Bash, and Thaddeus) published in the Astrophysical Journal Supplement Series, Volume 70, Number 4, August 1989 is summarized. The information presented here, which describes the interstellar environments of young clusters and some cluster physical characteristics, comes from observations published in the astronomical literature and the author's carbon monoxide (CO) emission line survey, and may help clarify our understanding of the interaction of massive stars with the interstellar medium.

Evaluation of improved land use data and canopy representation in BEIS with biogenic VOC measurements in California

EPA Pesticide Factsheets

The link provided access to all the datasets and metadata used in this manuscript for the model development and evaluation per Geoscientific Model Development's publication guidelines with the exception of the model output due to its size. This dataset is associated with the following publication:Bash , J., K. Baker , and M. Beaver. Evaluation of improved land use and canopy representation in BEIS v3.61 with biogenic VOC measurements in California. Geoscientific Model Development. Copernicus Publications, Katlenburg-Lindau, GERMANY, 9: 2191-2207, (2016).

New Methodology for First Principle Calculations of Electrical Levels for Radiation Induced Defects in Silicates

DTIC Science & Technology

2005-02-22

1993). 72 U. Itoh, Y. Toyoshima, H . Onuki , N. Washida, and T. Ibuki, J. Chem. Phys. 85, 4867 (1986). 73 M. J. Field, P. A. Bash, and M. Karplus, J...the following publi- cations: 1. V. B. Sulimov, P. V. Sushko, A. H . Edwards, A. L. Shluger, and A. M. Stoneham, ”Asymmetry and log-range character of...lattice deformation by neu- tral oxygen vacancy in alpha-quartz”, Physical Re- view B, 66, p. 024108, (2002). 2. A. H . Edwards, P. V. Sushko, A. L

Neo-Deterministic Seismic Hazard Assessment at Watts Bar Nuclear Power Plant Site, Tennessee, USA

NASA Astrophysics Data System (ADS)

Brandmayr, E.; Cameron, C.; Vaccari, F.; Fasan, M.; Romanelli, F.; Magrin, A.; Vlahovic, G.

2017-12-01

Watts Bar Nuclear Power Plant (WBNPP) is located within the Eastern Tennessee Seismic Zone (ETSZ), the second most naturally active seismic zone in the US east of the Rocky Mountains. The largest instrumental earthquakes in the ETSZ are M 4.6, although paleoseismic evidence supports events of M≥6.5. Events are mainly strike-slip and occur on steeply dipping planes at an average depth of 13 km. In this work, we apply the neo-deterministic seismic hazard assessment to estimate the potential seismic input at the plant site, which has been recently targeted by the Nuclear Regulatory Commission for a seismic hazard reevaluation. First, we perform a parametric test on some seismic source characteristics (i.e. distance, depth, strike, dip and rake) using a one-dimensional regional bedrock model to define the most conservative scenario earthquakes. Then, for the selected scenario earthquakes, the estimate of the ground motion input at WBNPP is refined using a two-dimensional local structural model (based on the plant's operator documentation) with topography, thus looking for site amplification and different possible rupture processes at the source. WBNNP features a safe shutdown earthquake (SSE) design with PGA of 0.18 g and maximum spectral amplification (SA, 5% damped) of 0.46 g (at periods between 0.15 and 0.5 s). Our results suggest that, although for most of the considered scenarios the PGA is relatively low, SSE values can be reached and exceeded in the case of the most conservative scenario earthquakes.

Helping coastal communities at risk from tsunamis: the role of U.S. Geological Survey research

USGS Publications Warehouse

Geist, Eric L.; Gelfenbaum, Guy R.; Jaffe, Bruce E.; Reid, Jane A.

2000-01-01

In 1946, 1960, and 1964, major tsunamis (giant sea waves usually caused by earthquakes or submarine landslides) struck coastal areas of the Pacific Ocean. In the U.S. alone, these tsunamis killed hundreds of people and caused many tens of millions of dollars in damage. Recent events in Papua New Guinea (1998) and elsewhere are reminders that a catastrophic tsunami could strike U.S. coasts at any time. The USGS, working closely with NOAA and other partners in the National Tsunami Hazard Mitigation Program, is helping to reduce losses from tsunamis through increased hazard assessment and improved real-time warning systems.

Use it or lose it--the hazards of bed rest and inactivity.

PubMed Central

Corcoran, P. J.

1991-01-01

Professional experience and lay wisdom teach us the benefits of exercise and the hazards of idleness. Yet the myth persists that "bed rest is good for you" when ill or convalescing. Abundant scientific evidence in the past 50 years has demonstrated the specific damage done to each of the body's organ systems by inactivity. Both aging and inactivity lead to strikingly similar kinds of deterioration. I summarize the data from military and veterans' hospitals, rehabilitation experience, aerospace research, and gerontology and review the physiologic and metabolic changes of aging and inactivity, along with strategies to help prevent the iatrogenic complications of bed rest. PMID:1866946

Maritime Standards for Compliance Safety and Health Officers (Instructor Manual). Volume 3

DTIC Science & Technology

1981-03-01

and striking tools "o Hamers "o Sledge hsmers "o Riveting hamners. 7. Hazards and health effects associated with the use of hand tools o Loss of eyes...lettered starting at the keel, A-B-C, etc. Strakes are classified inner skin, outer or cover, clinker or in and out, forefoot , shoe, boss, sheer, and

Environmental Assessment for the Removal of a Flightline Bird Air Strike Hazard, Eielson Air Force Base, Alaska

DTIC Science & Technology

2007-01-01

periphery of the lake grows emergent aquatic vegetation such as typhus and different sedge varieties. 3.2.2 Aquatic/Fishery Resources 3.2.2.1...that 98.1 percent of Eielson native wetlands are of low quality. Most of these wetlands are classified as black spruce or alder/willow scrub /shrub

North-South Asymmetric Solar Cycle Evolution: Signatures in the Photosphere and Consequences in the Corona

NASA Astrophysics Data System (ADS)

Virtanen, I. I.; Mursula, K.

2014-02-01

The heliospheric current sheet is the continuum of the coronal magnetic equator that divides the heliospheric magnetic field into two sectors (polarities). Several recent studies have shown that the heliospheric current sheet is southward shifted during approximately 3 years in the solar declining phase (the so-called bashful ballerina phenomenon). In this article we study the hemispherical asymmetry in the photospheric and coronal magnetic fields using Wilcox Solar Observatory measurements of the photospheric magnetic field since 1976 as well as the potential field source surface model. Multipole analysis of the photospheric magnetic field shows that during the late declining phase of solar cycles since the 1970s, the "bashful ballerina phenomenon" is a consequence of the g^{0}_{2} quadrupole term, signed oppositely to the dipole moment. Surges of new flux transport magnetic field from low latitudes to the poles, thus leading to a systematically varying contribution to the g^{0}_{2}-term from different latitudes. In the case of a north-south asymmetric flux production, this is seen as a quadrupole contribution traveling toward higher latitudes. When the quadrupole term is largest, the main contribution comes from the polar latitudes. At least during the four recent solar cycles, the g^{0}_{2}-term arises because the magnitude of the southern polar field is larger than the magnitude found in the north in the declining phase of the cycle. In the heliosphere this hemispheric asymmetry of the coronal fields is seen as a southward shift of the heliospheric current sheet by about 2°.

North south asymmetry in the coronal and photospheric magnetic fields

NASA Astrophysics Data System (ADS)

Virtanen, I.; Mursula, K.

2013-12-01

Several recent studies have shown that the Heliospheric current sheet (HCS) is southward shifted during about three years in the solar declining phase (the so-called bashful ballerina phenomenon). We study the hemispherical asymmetry in the photospheric and coronal magnetic fields using Wilcox Solar Observatory (WSO) measurements of the photospheric magnetic field since 1976 and the potential field source surface (PFSS) model. Multipole analysis of the photospheric magnetic field shows that during the late declining phase of solar cycles since 1970s, bashful ballerina phenomenon is a consequence of g02 quadrupole term, signed oppositely to the dipole moment. Surges of new flux transport magnetic field from low latitudes to the poles, thus leading to a systematically varying contribution to the g02-term from different latitudes. In the case of a north-south asymmetric flux production this is seen as a quadrupole contribution traveling towards higher latitudes. When the quadrupole term is largest the main contribution comes from the polar latitudes. At least during the four recent solar cycles the g02-term arises because the magnitude of the southern polar field is larger than in the north in the declining phase of the cycle. Magnetic flux is transported polewards by the meridional flow and it is most likely that besides the north-south asymmetric production of the magnetic flux, also the asymmetric transportation may significantly contribute to the observed asymmetry of polar field intensities. The overall activity during solar cycle is not significantly different in the northern and southern hemispheres, but hemispheres tend to develop in a different phase.

Coulomb stress transfer and accumulation on the Sagaing Fault, Myanmar, over the past 110 years and its implications for seismic hazard

NASA Astrophysics Data System (ADS)

Xiong, X.; Shan, B.; Zhou, Y. M.; Wei, S. J.; Li, Y. D.; Wang, R. J.; Zheng, Y.

2017-05-01

Myanmar is drawing rapidly increasing attention from the world for its seismic hazard. The Sagaing Fault (SF), an active right-lateral strike-slip fault passing through Myanmar, has been being the source of serious seismic damage of the country. Thus, awareness of seismic hazard assessment of this region is of pivotal significance by taking into account the interaction and migration of earthquakes with respect to time and space. We investigated a seismic series comprising10 earthquakes with M > 6.5 that occurred along the SF since 1906. The Coulomb failure stress modeling exhibits significant interactions among the earthquakes. After the 1906 earthquake, eight out of nine earthquakes occurred in the positively stress-enhanced zone of the preceding earthquakes, verifying that the hypothesis of earthquake triggering is applicable on the SF. Moreover, we identified three visible positively stressed earthquake gaps on the central and southern SF, on which seismic hazard is increased.

Coseismic displacement caused by the Mw 6.1 Mashhad earthquake in NE Iran from Sentinel-1A TOPS radar images

NASA Astrophysics Data System (ADS)

Su, Z.; Hu, J. C.; Talebian, M.

2017-12-01

Determining the relationship between crustal movement and associated slip partitioning is essential for understanding earthquake source and addressing the proposed models of a potential earthquake hazard. An Mw 6.1 earthquake struck the southeastern margin of the Mashhad valley in the northeast of Iran on 5 April 2017. In this study, we use both the ascending and descending mode of Sentinel-1A TOPS satellite data to characterize coseismic deformation pattern and to inverse the coseismic slip distribution on the fault patches. The best fitting model predicts that the coseismic rupture occurs along a fault plane with strike of 324.4º and dip of 28.1ºE. Our results show the fault tip does not propagate to the ground surface, and the predicted coseismic slip on the surface is about 0.11 m located on the hanging wall of the fault. Significant slip is concentrated on the fault patches at depth of 4-8 km and an along-strike distance of 10 km with varying slip magnitude from 0.1 m to 0.9 m. The fault slip is composed by thrusting with right-lateral strike slip, which is consistent with the focal mechanism solution. The over-thrusting was occurred from the depth of 14 km and terminated at the 4 km depth. While the right-lateral strike slip was only concentrated at a shallower depth of 4 to 8 km depth with the maximum slip of 0.9 m. The seismic moment release of our preferred fault model is 1.71×1018 Nm, equivalent to Mw 6.16 event. The Coulomb failure stress (CFS) calculated by the preferred fault model predicts significant positive CFS change on the three paralleled subsidiary faults of the southernmost Mashhad and Kashafrud fault, the Tus, Sorkhdeh and Natu faults. Consequently, these segments should be considered to have increasing of risk for future seismic hazard. Although most of the northward motion of the Lut and Central Iranian Blocks have been absorbed by the crustal shortening (e.g. thrusting and folding along the Binalud and Kopeh Dagh), simple strike-slip faulting also play an important role in the slip partitioning from the north to the south in NE Iran.

Hazardous substances releases associated with Hurricanes Katrina and Rita in industrial settings, Louisiana and Texas.

PubMed

Ruckart, Perri Zeitz; Orr, Maureen F; Lanier, Kenneth; Koehler, Allison

2008-11-15

The scientific literature concerning the public health response to the unprecedented hurricanes striking the Gulf Coast in August and September 2005 has focused mainly on assessing health-related needs and surveillance of injuries, infectious diseases, and other illnesses. However, the hurricanes also resulted in unintended hazardous substances releases in the affected states. Data from two states (Louisiana and Texas) participating in the Hazardous Substances Emergency Events Surveillance (HSEES) system were analyzed to describe the characteristics of hazardous substances releases in industrial settings associated with Hurricanes Katrina and Rita. HSEES is an active multi-state Web-based surveillance system maintained by the Agency for Toxic Substances and Disease Registry (ATSDR). In 2005, 166 hurricane-related hazardous substances events in industrial settings in Louisiana and Texas were reported. Most (72.3%) releases were due to emergency shut downs in preparation for the hurricanes and start-ups after the hurricanes. Emphasis is given to the contributing causal factors, hazardous substances released, and event scenarios. Recommendations are made to prevent or minimize acute releases of hazardous substances during future hurricanes, including installing backup power generation, securing equipment and piping to withstand high winds, establishing procedures to shutdown process operations safely, following established and up-to-date start-up procedures and checklists, and carefully performing pre-start-up safety reviews.

Environmental Review for the CV-22 Beddown at Yokota Air Base, Japan

DTIC Science & Technology

2015-02-24

3-7 (U) Figure 3-5. Low-Frequency Noise Effects Thresholds Developed by the Okinawa...Strike Hazard (U) Bgs below ground surface (U) BMPs Best Management Practices (U) BOD Biochemical Oxygen Demand (U) BOE Board of Education. (U) BWC...Noise Equivalent Level (U) CO carbon monoxide (U) CONUS Continental United States (U) CTIT Turbine Inlet Temperature , in degrees Celsius (U) CVW-5

Preliminary Earthquake Hazard Map of Afghanistan

USGS Publications Warehouse

Boyd, Oliver S.; Mueller, Charles S.; Rukstales, Kenneth S.

2007-01-01

Introduction Earthquakes represent a serious threat to the people and institutions of Afghanistan. As part of a United States Agency for International Development (USAID) effort to assess the resource potential and seismic hazards of Afghanistan, the Seismic Hazard Mapping group of the United States Geological Survey (USGS) has prepared a series of probabilistic seismic hazard maps that help quantify the expected frequency and strength of ground shaking nationwide. To construct the maps, we do a complete hazard analysis for each of ~35,000 sites in the study area. We use a probabilistic methodology that accounts for all potential seismic sources and their rates of earthquake activity, and we incorporate modeling uncertainty by using logic trees for source and ground-motion parameters. See the Appendix for an explanation of probabilistic seismic hazard analysis and discussion of seismic risk. Afghanistan occupies a southward-projecting, relatively stable promontory of the Eurasian tectonic plate (Ambraseys and Bilham, 2003; Wheeler and others, 2005). Active plate boundaries, however, surround Afghanistan on the west, south, and east. To the west, the Arabian plate moves northward relative to Eurasia at about 3 cm/yr. The active plate boundary trends northwestward through the Zagros region of southwestern Iran. Deformation is accommodated throughout the territory of Iran; major structures include several north-south-trending, right-lateral strike-slip fault systems in the east and, farther to the north, a series of east-west-trending reverse- and strike-slip faults. This deformation apparently does not cross the border into relatively stable western Afghanistan. In the east, the Indian plate moves northward relative to Eurasia at a rate of about 4 cm/yr. A broad, transpressional plate-boundary zone extends into eastern Afghanistan, trending southwestward from the Hindu Kush in northeast Afghanistan, through Kabul, and along the Afghanistan-Pakistan border. Deformation here is expressed as a belt of major, north-northeast-trending, left-lateral strike-slip faults and abundant seismicity. The seismicity intensifies farther to the northeast and includes a prominent zone of deep earthquakes associated with northward subduction of the Indian plate beneath Eurasia that extends beneath the Hindu Kush and Pamirs Mountains. Production of the seismic hazard maps is challenging because the geological and seismological data required to produce a seismic hazard model are limited. The data that are available for this project include historical seismicity and poorly constrained slip rates on only a few of the many active faults in the country. Much of the hazard is derived from a new catalog of historical earthquakes: from 1964 to the present, with magnitude equal to or greater than about 4.5, and with depth between 0 and 250 kilometers. We also include four specific faults in the model: the Chaman fault with an assigned slip rate of 10 mm/yr, the Central Badakhshan fault with an assigned slip rate of 12 mm/yr, the Darvaz fault with an assigned slip rate of 7 mm/yr, and the Hari Rud fault with an assigned slip rate of 2 mm/yr. For these faults and for shallow seismicity less than 50 km deep, we incorporate published ground-motion estimates from tectonically active regions of western North America, Europe, and the Middle East. Ground-motion estimates for deeper seismicity are derived from data in subduction environments. We apply estimates derived for tectonic regions where subduction is the main tectonic process for intermediate-depth seismicity between 50- and 250-km depth. Within the framework of these limitations, we have developed a preliminary probabilistic seismic-hazard assessment of Afghanistan, the type of analysis that underpins the seismic components of modern building codes in the United States. The assessment includes maps of estimated peak ground-acceleration (PGA), 0.2-second spectral acceleration (SA), and 1.0-secon

The 2016 Mihoub (north-central Algeria) earthquake sequence: Seismological and tectonic aspects

NASA Astrophysics Data System (ADS)

Khelif, M. F.; Yelles-Chaouche, A.; Benaissa, Z.; Semmane, F.; Beldjoudi, H.; Haned, A.; Issaadi, A.; Chami, A.; Chimouni, R.; Harbi, A.; Maouche, S.; Dabbouz, G.; Aidi, C.; Kherroubi, A.

2018-06-01

On 28 May 2016 at 23:54 (UTC), an Mw5.4 earthquake occurred in Mihoub village, Algeria, 60 km southeast of Algiers. This earthquake was the largest event in a sequence recorded from 10 April to 15 July 2016. In addition to the permanent national network, a temporary network was installed in the epicentral region after this shock. Recorded event locations allow us to give a general overview of the sequence and reveal the existence of two main fault segments. The first segment, on which the first event in the sequence was located, is near-vertical and trends E-W. The second fault plane, on which the largest event of the sequence was located, dips to the southeast and strikes NE-SW. A total of 46 well-constrained focal mechanisms were calculated. The events located on the E-W-striking fault segment show mainly right-lateral strike-slip (strike N70°E, dip 77° to the SSE, rake 150°). The events located on the NE-SW-striking segment show mainly reverse faulting (strike N60°E, dip 70° to the SE, rake 130°). We calculated the static stress change caused by the first event (Md4.9) of the sequence; the result shows that the fault plane of the largest event in the sequence (Mw5.4) and most of the aftershocks occurred within an area of increased Coulomb stress. Moreover, using the focal mechanisms calculated in this work, we estimated the orientations of the main axes of the local stress tensor ellipsoid. The results confirm previous findings that the general stress field in this area shows orientations aligned NNW-SSE to NW-SE. The 2016 Mihoub earthquake sequence study thus improves our understanding of seismic hazard in north-central Algeria.

Coseismic rupturing stopped by Aso volcano during the 2016 Mw 7.1 Kumamoto earthquake, Japan.

PubMed

Lin, A; Satsukawa, T; Wang, M; Mohammadi Asl, Z; Fueta, R; Nakajima, F

2016-11-18

Field investigations and seismic data show that the 16 April 2016 moment magnitude (M w ) 7.1 Kumamoto earthquake produced a ~40-kilometer-long surface rupture zone along the northeast-southwest-striking Hinagu-Futagawa strike-slip fault zone and newly identified faults on the western side of Aso caldera, Kyushu Island, Japan. The coseismic surface ruptures cut Aso caldera, including two volcanic cones inside it, but terminate therein. The data show that northeastward propagation of coseismic rupturing terminated in Aso caldera because of the presence of magma beneath the Aso volcanic cluster. The seismogenic faults of the 2016 Kumamoto earthquake may require reassessment of the volcanic hazard in the vicinity of Aso volcano. Copyright © 2016, American Association for the Advancement of Science.

Integration and Testing of LCS Software

NASA Technical Reports Server (NTRS)

Wang, John

2014-01-01

Kennedy Space Center is in the midst of developing a command and control system for the launch of the next generation manned space vehicle. The Space Launch System (SLS) will launch using the new Spaceport Command and Control System (SCCS). As a member of the Software Integration and Test (SWIT) Team, command scripts, and bash scripts were written to assist in integration and testing of the Launch Control System (LCS), which is a component of SCCS. The short term and midterm tasks are for the most part completed. The long term tasks if time permits will require a presentation and demonstration.

Updating sea spray aerosol emissions in the Community Multiscale Air Quality (CMAQ) model version 5.0.2

EPA Pesticide Factsheets

The uploaded data consists of the BRACE Na aerosol observations paired with CMAQ model output, the updated model's parameterization of sea salt aerosol emission size distribution, and the model's parameterization of the sea salt emission factor as a function of sea surface temperature. This dataset is associated with the following publication:Gantt , B., J. Kelly , and J. Bash. Updating sea spray aerosol emissions in the Community Multiscale Air Quality (CMAQ) model version 5.0.2. Geoscientific Model Development. Copernicus Publications, Katlenburg-Lindau, GERMANY, 8: 3733-3746, (2015).

compuGUT: An in silico platform for simulating intestinal fermentation

NASA Astrophysics Data System (ADS)

Moorthy, Arun S.; Eberl, Hermann J.

The microbiota inhabiting the colon and its effect on health is a topic of significant interest. In this paper, we describe the compuGUT - a simulation tool developed to assist in exploring interactions between intestinal microbiota and their environment. The primary numerical machinery is implemented in C, and the accessory scripts for loading and visualization are prepared in bash (LINUX) and R. SUNDIALS libraries are employed for numerical integration, and googleVis API for interactive visualization. Supplementary material includes a concise description of the underlying mathematical model, and detailed characterization of numerical errors and computing times associated with implementation parameters.

1957 Gobi-Altay, Mongolia, earthquake as a prototype for southern California's most devastating earthquake

USGS Publications Warehouse

Bayarsayhan, C.; Bayasgalan, A.; Enhtuvshin, B.; Hudnut, K.W.; Kurushin, R.A.; Molnar, P.; Olziybat, M.

1996-01-01

The 1957 Gobi-Altay earthquake was associated with both strike-slip and thrust faulting, processes similar to those along the San Andreas fault and the faults bounding the San Gabriel Mountains just north of Los Angeles, California. Clearly, a major rupture either on the San Andreas fault north of Los Angeles or on the thrust faults bounding the Los Angeles basin poses a serious hazard to inhabitants of that area. By analogy with the Gobi-Altay earthquake, we suggest that simultaneous rupturing of both the San Andreas fault and the thrust faults nearer Los Angeles is a real possibility that amplifies the hazard posed by ruptures on either fault system separately.

Tsunami Hazards - A National Threat

USGS Publications Warehouse

,

2006-01-01

In December 2004, when a tsunami killed more than 200,000 people in 11 countries around the Indian Ocean, the United States was reminded of its own tsunami risks. In fact, devastating tsunamis have struck North America before and are sure to strike again. Especially vulnerable are the five Pacific States--Hawaii, Alaska, Washington, Oregon, and California--and the U.S. Caribbean islands. In the wake of the Indian Ocean disaster, the United States is redoubling its efforts to assess the Nation's tsunami hazards, provide tsunami education, and improve its system for tsunami warning. The U.S. Geological Survey (USGS) is helping to meet these needs, in partnership with the National Oceanic and Atmospheric Administration (NOAA) and with coastal States and counties.

Ring discharge on the backsurface of a composite skin with ohmic anisotropy in response to frontal high current injection

NASA Astrophysics Data System (ADS)

Lee, T. S.; Robb, J. D.

The ring discharge hazard to a carbon-reinforced-composites fuel tank skin under lightning strike conditions is investigated. A model of anisotropy in electric conductivity is adopted whereby longitudinal conductivity and transverse conductivity are considered separately. It is concluded that the current flow pattern contains a stagnation-dominated near-field region and a geometry-dominated far-field decaying region. While this pattern is unaltered by anisotropy in conductivity, the accompanying nonliner electrical field pattern is greatly distorted. It is noted that conclusions applicable to the ignition hazard which were derived from the model of a uniform scalar conductivity for the skin still remain intact.

Comparison of the KSC-ER Cloud-to-Ground Lightning Surveillance System (CGLSS) and the U.S. National Lightning Detection Network (NLDN)

NASA Technical Reports Server (NTRS)

Ward, Jennifer G.; Cummins, Kenneth L.; Krider, E. Philip

2008-01-01

The NASA Kennedy Space Center (KSC) and Air Force Eastern Range (ER) are located in a region of Florida that experiences the highest area density of lightning strikes to ground in the United States, with values approaching 16 fl/km 2/yr when accumulated in 10x10 km (100 sq km) grids (see Figure 1). Consequently, the KSC-ER use data derived from two cloud-to-ground (CG) lightning detection networks to detect hazardous weather, the "Cloud-to-Ground Lightning Surveillance System" (CGLSS) that is owned and operated by the Air Force and the U.S. National Lightning Detection Network (NLDN) that is owned and operated by Vaisala, Inc. These systems are used to provide lightning warnings for ground operations and to insure mission safety during space launches at the KSC-ER. In order to protect the rocket and shuttle fleets, NASA and the Air Force follow a set of lightning safety guidelines that are called the Lightning Launch Commit Criteria (LLCC). These rules are designed to insure that vehicles are not exposed to the hazards of natural or triggered lightning that would in any way jeopardize a mission or cause harm to the shuttle astronauts. Also, if any CG lightning strikes too close to a vehicle on a launch pad, it can cause time-consuming mission delays due to the extensive retests that are often required for vehicles and/or payloads when this occurs. If any CG lightning strike is missed or mis-located by even a small amount, the result could have significant safety implications, require expensive retests, or create unnecessary delays or scrubs in launches. Therefore, it is important to understand the performance of each lightning detection system in considerable detail.

New seismic hazard maps for Puerto Rico and the U.S. Virgin Islands

USGS Publications Warehouse

Mueller, C.; Frankel, A.; Petersen, M.; Leyendecker, E.

2010-01-01

The probabilistic methodology developed by the U.S. Geological Survey is applied to a new seismic hazard assessment for Puerto Rico and the U.S. Virgin Islands. Modeled seismic sources include gridded historical seismicity, subduction-interface and strike-slip faults with known slip rates, and two broad zones of crustal extension with seismicity rates constrained by GPS geodesy. We use attenuation relations from western North American and worldwide data, as well as a Caribbean-specific relation. Results are presented as maps of peak ground acceleration and 0.2- and 1.0-second spectral response acceleration for 2% and 10% probabilities of exceedance in 50 years (return periods of about 2,500 and 500 years, respectively). This paper describes the hazard model and maps that were balloted by the Building Seismic Safety Council and recommended for the 2003 NEHRP Provisions and the 2006 International Building Code. ?? 2010, Earthquake Engineering Research Institute.

New constraints shed light on strike-slip faulting beneath the southern Apennines (Italy): The 21 August 1962 Irpinia multiple earthquake

NASA Astrophysics Data System (ADS)

Vannoli, Paola; Bernardi, Fabrizio; Palombo, Barbara; Vannucci, Gianfranco; Console, Rodolfo; Ferrari, Graziano

2016-11-01

On 21 August 1962 an earthquake sequence set off near the city of Benevento, in Italy's southern Apennines. Three earthquakes, the largest having Mw 6.1, struck virtually the same area in less than 40 min (at 18:09, 18:19 and 18:44 UTC, respectively). Several historical earthquakes hit this region, and its seismic hazard is accordingly among the highest countrywide. Although poorly understood in the past, the seismotectonics of this region can be revealed by the 1962 sequence, being the only significant earthquake in the area for which modern seismograms are available. We determine location, magnitude, and nodal planes of the first event (18:09 UTC) of the sequence. The focal mechanism exhibits dominant strike-slip rupture along a north-dipping, E-W striking plane or along a west-dipping, N-S striking plane. Either of these solutions is significantly different from the kinematics of the typical large earthquakes occurring along the crest of the Southern Apennines, such as the 23 November 1980 Irpinia earthquake (Mw 6.9), caused by predominant normal faulting along NW-SE-striking planes. The epicentre of the 21 August 1962, 18:09 event is located immediately east of the chain axis, near one of the three north-dipping, E-W striking oblique-slip sources thought to have caused one of the three main events of the December 1456 sequence (Io XI MCS), the most destructive events in the southern Apennines known to date. We maintain that the 21 August 1962, 18:09 earthquake occurred along the E-W striking fault system responsible for the southernmost event of the 1456 sequence and for two smaller but instrumentally documented events that occurred on 6 May 1971 (Mw 5.0) and 27 September 2012 (Mw 4.6), further suggesting that normal faulting is not the dominant tectonic style in this portion of the Italian peninsula.

Near-shore Evaluation of Holocene Faulting and Earthquake Hazard in the New York City Metropolitan Region

NASA Astrophysics Data System (ADS)

Cormier, M. H.; King, J. W.; Seeber, L.; Heil, C. W., Jr.; Caccioppoli, B.

2016-12-01

During its relatively short historic period, the Atlantic Seaboard of North America has experienced a few M6+ earthquakes. These events raise the specter of a similar earthquake occurring anywhere along the eastern seaboard, including in the greater New York City (NYC) metropolitan area. Indeed, the NYC Seismic Zone is one of several concentrations of earthquake activity that stand out in the field of epicenters over eastern North America. Various lines of evidence point to a maximum magnitude in the M7 range for metropolitan NYC - a dramatic scenario that is counterbalanced by the low probability of such an event. Several faults mapped near NYC strike NW, sub-normal to the NE-striking structural trends of the Appalachians, and all earthquake sequences with well-established fault sources in the NYC seismic zone originate from NW-striking faults. With funding from the USGS Earthquake Hazard Program, we recently (July 2016) collected 85 km of high-resolution sub-bottom (CHIRP) profiles along the north shore of western Long Island Sound, immediately adjacent to metropolitan NYC. This survey area is characterized by a smooth, 15.5 kyr-old erosional surface and overlying strata with small original relief. CHIRP sonar profiles of these reflectors are expected to resolve fault or fold-related vertical relief (if present) greater than 50 cm. They would also resolve horizontal fault displacements with similar resolution, as may be expressed by offsets of either sedimentary or geomorphic features. No sedimentary cover on the land portion of the metro area offers such ideal reference surfaces, which are continuous in both time and space. Seismic profiles have a spacing of 200 m and have been acquired mostly perpendicular to the NW-striking faults mapped on land. These new data will be analyzed systematically for all resolvable features and then interpreted, distinguishing sedimentary, geomorphic, and tectonic features. The absence of evidence of post-glacial tectonic deformation would be a reliable negative result with implications regarding the lateral dimensions and southeastward continuity of the brittle faults mapped on land, and their potential for generation of large earthquakes with surface ruptures.

Interaction Potency of Single-Walled Carbon Nanotubes with DNAs: A Novel Assay for Assessment of Hazard Risk

PubMed Central

Yao, Chunhe; Carlisi, Cristina; Li, Yuning; Chen, Da; Ding, Jianfu; Feng, Yong-Lai

2016-01-01

Increasing use of single-walled carbon nanotubes (SWCNTs) necessitates a novel method for hazard risk assessment. In this work, we investigated the interaction of several types of commercial SWCNTs with single-stranded (ss) and double-stranded (ds) DNA oligonucleotides (20-mer and 20 bp). Based on the results achieved, we proposed a novel assay that employed the DNA interaction potency to assess the hazard risk of SWCNTs. It was found that SWCNTs in different sizes or different batches of the same product number of SWCNTs showed dramatically different potency of interaction with DNAs. In addition, the same SWCNTs also exerted strikingly different interaction potency with ss- versus ds- DNAs. The interaction rates of SWCNTs with DNAs were investigated, which could be utilized as the indicator of potential hazard for acute exposure. Compared to solid SWCNTs, the SWCNTs dispersed in liquid medium (2% sodium cholate solution) exhibited dramatically different interaction potency with DNAs. This indicates that the exposure medium may greatly influence the subsequent toxicity and hazard risk produced by SWCNTs. Based on the findings of dose-dependences and time-dependences from the interactions between SWCNTs and DNAs, a new chemistry based assay for hazard risk assessment of nanomaterials including SWCNTs has been presented. PMID:27936089

Interaction Potency of Single-Walled Carbon Nanotubes with DNAs: A Novel Assay for Assessment of Hazard Risk.

PubMed

Yao, Chunhe; Carlisi, Cristina; Li, Yuning; Chen, Da; Ding, Jianfu; Feng, Yong-Lai

2016-01-01

Increasing use of single-walled carbon nanotubes (SWCNTs) necessitates a novel method for hazard risk assessment. In this work, we investigated the interaction of several types of commercial SWCNTs with single-stranded (ss) and double-stranded (ds) DNA oligonucleotides (20-mer and 20 bp). Based on the results achieved, we proposed a novel assay that employed the DNA interaction potency to assess the hazard risk of SWCNTs. It was found that SWCNTs in different sizes or different batches of the same product number of SWCNTs showed dramatically different potency of interaction with DNAs. In addition, the same SWCNTs also exerted strikingly different interaction potency with ss- versus ds- DNAs. The interaction rates of SWCNTs with DNAs were investigated, which could be utilized as the indicator of potential hazard for acute exposure. Compared to solid SWCNTs, the SWCNTs dispersed in liquid medium (2% sodium cholate solution) exhibited dramatically different interaction potency with DNAs. This indicates that the exposure medium may greatly influence the subsequent toxicity and hazard risk produced by SWCNTs. Based on the findings of dose-dependences and time-dependences from the interactions between SWCNTs and DNAs, a new chemistry based assay for hazard risk assessment of nanomaterials including SWCNTs has been presented.

Photospheric and coronal magnetic fields in six magnetographs. I. Consistent evolution of the bashful ballerina

NASA Astrophysics Data System (ADS)

Virtanen, Ilpo; Mursula, Kalevi

2016-06-01

Aims: We study the long-term evolution of photospheric and coronal magnetic fields and the heliospheric current sheet (HCS), especially its north-south asymmetry. Special attention is paid to the reliability of the six data sets used in this study and to the consistency of the results based on these data sets. Methods: We use synoptic maps constructed from Wilcox Solar Observatory (WSO), Mount Wilson Observatory (MWO), Kitt Peak (KP), SOLIS, SOHO/MDI, and SDO/HMI measurements of the photospheric field and the potential field source surface (PFSS) model. Results: The six data sets depict a fairly similar long-term evolution of magnetic fields and the heliospheric current sheet, including polarity reversals and hemispheric asymmetry. However, there are time intervals of several years long, when first KP measurements in the 1970s and 1980s, and later WSO measurements in the 1990s and early 2000s, significantly deviate from the other simultaneous data sets, reflecting likely errors at these times. All of the six magnetographs agree on the southward shift of the heliospheric current sheet (the so-called bashful ballerina phenomenon) in the declining to minimum phase of the solar cycle during a few years of the five included cycles. We show that during solar cycles 20-22, the southward shift of the HCS is mainly due to the axial quadrupole term, reflecting the stronger magnetic field intensity at the southern pole during these times. During cycle 23 the asymmetry is less persistent and mainly due to higher harmonics than the quadrupole term. Currently, in the early declining phase of cycle 24, the HCS is also shifted southward and is mainly due to the axial quadrupole as for most earlier cycles. This further emphasizes the special character of the global solar field during cycle 23.

Comparing the solar magnetic field in the corona and in the inner heliosphere during solar cycles 21-23

NASA Astrophysics Data System (ADS)

Virtanen, I. I.; Mursula, K.

2009-04-01

We compare the open solar magnetic field estimated by the PFSS model based on the WSO photospheric field observations, with the inner heliospheric magnetic field. We trace the observed radial HMF into the coronal PFSS boundary at 2.5 solar radii using the observed solar wind velocity, and determine the PFSS model field at the line-of-sight footpoint. Comparing the two field values, we calculate the power n of the apparent decrease of the radial field. According to expectations based on Maxwell's equations, also reproduced by Parker's HMF model, the radial HMF field should decrease with n=2. However, comparison gives considerably lower values of n, indicating the effect of HCS in the PFSS model and the possible superexpansion. The n values vary with solar cycle, being roughly 1.3-1.4 at minima and about 1.7 at maxima. Interestingly, the n values for the two HMF sectors show systematic differences in the late declining to minimum phase, with smaller n values for the HMF sector dominant in the northern hemisphere. This is in agreement with the smaller field value in the northern hemisphere and the southward shifted HCS, summarized by the concept of the bashful ballerina. We also find that the values of n during the recent years, in the late declining phase of solar cycle 23, are significantly larger than during the same phase of the previous cycles. This agrees with the exceptionally large tilt of the solar dipole at the end of cycle 23. We also find that the bashful ballerina appears even during SC 23 but the related hemispheric differences are smaller than during the previous cycles.

Atmospheric electrical modeling in support of the NASA F106 Storm Hazards Project

NASA Technical Reports Server (NTRS)

Helsdon, J. H.

1986-01-01

With the use of composite (non-metallic) and microelectronics becoming more prevalent in the construction of both military and commercial aircraft, the control systems have become more susceptible to damage or failure from electromagnetic transients. One source of such transients is the lightning discharge. In order to study the effects of the lightning discharge on the vital components of an aircraft, NASA Langley Research Center has undertaken a Storm Hazards Program in which a specially instrumented F106B jet aircraft is flown into active thunderstorms with the intention of being struck by lightning. One of the specific purposes of the program is to quantify the environmental conditions which are conductive to aircraft lightning strikes.

Environmental Assessment (EA) for Construct Base Civil Engineering Complex at McConnell AFB

DTIC Science & Technology

2003-07-14

Engineer Squadron (22 CES/ CEVA ),53000 Hutchinson Street, Suite 109,McConnell AFB,KS,67221-3617 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING...Command Air Refueling Group Air Refueling Squadron Air Refueling Wing Bird Aircraft Strike Hazard Base Civil Engineer Best Management Practices...1991, in an "Economic Analysis", performed by Wilson and Company , dated 14 October 1993, and a repeat "Economic Analysis", dated 10 February 2000

GAS DISCHARGE DEVICES

DOEpatents

Arrol, W.J.; Jefferson, S.

1957-08-27

The construction of gas discharge devices where the object is to provide a gas discharge device having a high dark current and stabilized striking voltage is described. The inventors have discovered that the introduction of tritium gas into a discharge device with a subsequent electrical discharge in the device will deposit tritium on the inside of the chamber. The tritium acts to emit beta rays amd is an effective and non-hazardous way of improving the abovementioned discharge tube characteristics

International Students and Gender-Based Violence.

PubMed

Forbes-Mewett, Helen; McCulloch, Jude

2016-03-01

Headlines such as "Man Jailed for Train Station Attack on Indian Student," "Fatal Stabbing Hits Indian Student Hopes," and "Indian Student Bashings on the Rise in Sydney" highlight violent crimes against male international students by strangers in public spaces. The media reports run contrary to the perceptions of our interviewees who suggest that violence against female international students by known perpetrators in private spaces is common. We argue that intersecting inequalities relating to gender, race, and class are often compounded by the status of "international student." Discussions focus on various forms of gender-based violence and gender violence education and support programs in Australia and the United States. © The Author(s) 2015.

Variations in community exposure to lahar hazards from multiple volcanoes in Washington State (USA)

USGS Publications Warehouse

Diefenbach, Angela K.; Wood, Nathan J.; Ewert, John W.

2015-01-01

Understanding how communities are vulnerable to lahar hazards provides critical input for effective design and implementation of volcano hazard preparedness and mitigation strategies. Past vulnerability assessments have focused largely on hazards posed by a single volcano, even though communities and officials in many parts of the world must plan for and contend with hazards associated with multiple volcanoes. To better understand community vulnerability in regions with multiple volcanic threats, we characterize and compare variations in community exposure to lahar hazards associated with five active volcanoes in Washington State, USA—Mount Baker, Glacier Peak, Mount Rainier, Mount Adams and Mount St. Helens—each having the potential to generate catastrophic lahars that could strike communities tens of kilometers downstream. We use geospatial datasets that represent various population indicators (e.g., land cover, residents, employees, tourists) along with mapped lahar-hazard boundaries at each volcano to determine the distributions of populations within communities that occupy lahar-prone areas. We estimate that Washington lahar-hazard zones collectively contain 191,555 residents, 108,719 employees, 433 public venues that attract visitors, and 354 dependent-care facilities that house individuals that will need assistance to evacuate. We find that population exposure varies considerably across the State both in type (e.g., residential, tourist, employee) and distribution of people (e.g., urban to rural). We develop composite lahar-exposure indices to identify communities most at-risk and communities throughout the State who share common issues of vulnerability to lahar-hazards. We find that although lahars are a regional hazard that will impact communities in different ways there are commonalities in community exposure across multiple volcanoes. Results will aid emergency managers, local officials, and the public in educating at-risk populations and developing preparedness, mitigation, and recovery plans within and across communities.

Hazards and accessibility: combining and visualizing threat and open infrastructure data for disaster management

NASA Astrophysics Data System (ADS)

Tost, Jordi; Ehmel, Fabian; Heidmann, Frank; Olen, Stephanie M.; Bookhagen, Bodo

2018-05-01

The assessment of natural hazards and risk has traditionally been built upon the estimation of threat maps, which are used to depict potential danger posed by a particular hazard throughout a given area. But when a hazard event strikes, infrastructure is a significant factor that can determine if the situation becomes a disaster. The vulnerability of the population in a region does not only depend on the area's local threat, but also on the geographical accessibility of the area. This makes threat maps by themselves insufficient for supporting real-time decision-making, especially for those tasks that involve the use of the road network, such as management of relief operations, aid distribution, or planning of evacuation routes, among others. To overcome this problem, this paper proposes a multidisciplinary approach divided in two parts. First, data fusion of satellite-based threat data and open infrastructure data from OpenStreetMap, introducing a threat-based routing service. Second, the visualization of this data through cartographic generalization and schematization. This emphasizes critical areas along roads in a simple way and allows users to visually evaluate the impact natural hazards may have on infrastructure. We develop and illustrate this methodology with a case study of landslide threat for an area in Colombia.

Evolution of regional stress state based on faulting and folding near the pit river, Shasta county, California

NASA Astrophysics Data System (ADS)

Austin, Lauren Jean

We investigate the evolution of the regional stress state near the Pit River, northern California, in order to understand the faulting style in a tectonic transition zone and to inform the hazard analysis of Fault 3432 near the Pit 3 Dam. By analyzing faults and folds preserved in and adjacent to a diatomite mine north of the Pit River, we have determined principal stress directions preserved during the past million years. We find that the stress state has evolved from predominantly normal to strike slip and most recently to reverse, which is consistent with regional structures such as the extensional Hat Creek Fault to the south and the compressional folding of Mushroom Rock to the north. South of the Pit River, we still observe normal and strike slip faults, suggesting that changes in stress state are moving from north to south through time.

Spatial analysis of geologic and hydrologic features relating to sinkhole occurrence in Jefferson County, West Virginia

USGS Publications Warehouse

Doctor, Daniel H.; Doctor, Katarina Z.

2012-01-01

In this study the influence of geologic features related to sinkhole susceptibility was analyzed and the results were mapped for the region of Jefferson County, West Virginia. A model of sinkhole density was constructed using Geographically Weighted Regression (GWR) that estimated the relations among discrete geologic or hydrologic features and sinkhole density at each sinkhole location. Nine conditioning factors on sinkhole occurrence were considered as independent variables: distance to faults, fold axes, fracture traces oriented along bedrock strike, fracture traces oriented across bedrock strike, ponds, streams, springs, quarries, and interpolated depth to groundwater. GWR model parameter estimates for each variable were evaluated for significance, and the results were mapped. The results provide visual insight into the influence of these variables on localized sinkhole density, and can be used to provide an objective means of weighting conditioning factors in models of sinkhole susceptibility or hazard risk.

Radiated energy and the rupture process of the Denali fault earthquake sequence of 2002 from broadband teleseismic body waves

USGS Publications Warehouse

Choy, G.L.; Boatwright, J.

2004-01-01

Displacement, velocity, and velocity-squared records of P and SH body waves recorded at teleseismic distances are analyzed to determine the rupture characteristics of the Denali fault, Alaska, earthquake of 3 November 2002 (MW 7.9, Me 8.1). Three episodes of rupture can be identified from broadband (???0.1-5.0 Hz) waveforms. The Denali fault earthquake started as a MW 7.3 thrust event. Subsequent right-lateral strike-slip rupture events with centroid depths of 9 km occurred about 22 and 49 sec later. The teleseismic P waves are dominated by energy at intermediate frequencies (0.1-1 Hz) radiated by the thrust event, while the SH waves are dominated by energy at lower frequencies (0.05-0.2 Hz) radiated by the strike-slip events. The strike-slip events exhibit strong directivity in the teleseismic SH waves. Correcting the recorded P-wave acceleration spectra for the effect of the free surface yields an estimate of 2.8 ?? 1015 N m for the energy radiated by the thrust event. Correcting the recorded SH-wave acceleration spectra similarly yields an estimate of 3.3 ?? 10 16 N m for the energy radiated by the two strike-slip events. The average rupture velocity for the strike-slip rupture process is 1.1??-1.2??. The strike-slip events were located 90 and 188 km east of the epicenter. The rupture length over which significant or resolvable energy is radiated is, thus, far shorter than the 340-km fault length over which surface displacements were observed. However, the seismic moment released by these three events, 4 ?? 1020 N m, was approximately half the seismic moment determined from very low-frequency analyses of the earthquake. The difference in seismic moment can be reasonably attributed to slip on fault segments that did not radiate significant or coherent seismic energy. These results suggest that very large and great strike-slip earthquakes can generate stress pulses that rapidly produce substantial slip with negligible stress drop and little discernible radiated energy on fault segments distant from the initial point of nucleation. The existence of this energy-deficient rupture mode has important implications for the evaluation of the seismic hazard of very large strike-slip earthquakes.

Experimental evidence links volcanic particle characteristics to pyroclastic flow hazard

NASA Astrophysics Data System (ADS)

Dellino, Pierfrancesco; Büttner, Ralf; Dioguardi, Fabio; Doronzo, Domenico M.; La Volpe, Luigi; Mele, Daniela; Sonder, Ingo; Sulpizio, Roberto; Zimanowski, Bernd

2010-06-01

Pyroclastic flows represent the most hazardous events of explosive volcanism, one striking example being the famous historical eruption of Vesuvius that destroyed Pompeii (AD 79). Much of our knowledge of the mechanics of pyroclastic flows comes from theoretical models and numerical simulations. Valuable data are also stored in the geological record of past eruptions, including the particles contained in pyroclastic deposits, but the deposit characteristics are rarely used for quantifying the destructive potential of pyroclastic flows. By means of experiments, we validate a model that is based on data from pyroclastic deposits. The model allows the reconstruction of the current's fluid-dynamic behaviour. Model results are consistent with measured values of dynamic pressure in the experiments, and allow the quantification of the damage potential of pyroclastic flows.

The Implications of Strike-Slip Earthquake Source Properties on the Transform Boundary Development Process

NASA Astrophysics Data System (ADS)

Neely, J. S.; Huang, Y.; Furlong, K.

2017-12-01

Subduction-Transform Edge Propagator (STEP) faults, produced by the tearing of a subducting plate, allow us to study the development of a transform plate boundary and improve our understanding of both long-term geologic processes and short-term seismic hazards. The 280 km long San Cristobal Trough (SCT), formed by the tearing of the Australia plate as it subducts under the Pacific plate near the Solomon and Vanuatu subduction zones, shows along-strike variations in earthquake behaviors. The segment of the SCT closest to the tear rarely hosts earthquakes > Mw 6, whereas the SCT sections more than 80 - 100 km from the tear experience Mw7 earthquakes with repeated rupture along the same segments. To understand the effect of cumulative displacement on SCT seismicity, we analyze b-values, centroid-time delays and corner frequencies of the SCT earthquakes. We use the spectral ratio method based on Empirical Green's Functions (eGfs) to isolate source effects from propagation and site effects. We find high b-values along the SCT closest to the tear with values decreasing with distance before finally increasing again towards the far end of the SCT. Centroid time-delays for the Mw 7 strike-slip earthquakes increase with distance from the tear, but corner frequency estimates for a recent sequence of Mw 7 earthquakes are approximately equal, indicating a growing complexity in earthquake behavior with distance from the tear due to a displacement-driven transform boundary development process (see figure). The increasing complexity possibly stems from the earthquakes along the eastern SCT rupturing through multiple asperities resulting in multiple moment pulses. If not for the bounding Vanuatu subduction zone at the far end of the SCT, the eastern SCT section, which has experienced the most displacement, might be capable of hosting larger earthquakes. When assessing the seismic hazard of other STEP faults, cumulative fault displacement should be considered a key input in determining potential earthquake size.

Potential earthquake faults offshore Southern California, from the eastern Santa Barbara Channel south to Dana Point

USGS Publications Warehouse

Fisher, M.A.; Sorlien, C.C.; Sliter, R.W.

2009-01-01

Urban areas in Southern California are at risk from major earthquakes, not only quakes generated by long-recognized onshore faults but also ones that occur along poorly understood offshore faults. We summarize recent research findings concerning these lesser known faults. Research by the U.S. Geological Survey during the past five years indicates that these faults from the eastern Santa Barbara Channel south to Dana Point pose a potential earthquake threat. Historical seismicity in this area indicates that, in general, offshore faults can unleash earthquakes having at least moderate (M 5-6) magnitude. Estimating the earthquake hazard in Southern California is complicated by strain partitioning and by inheritance of structures from early tectonic episodes. The three main episodes are Mesozoic through early Miocene subduction, early Miocene crustal extension coeval with rotation of the Western Transverse Ranges, and Pliocene and younger transpression related to plate-boundary motion along the San Andreas Fault. Additional complication in the analysis of earthquake hazards derives from the partitioning of tectonic strain into strike-slip and thrust components along separate but kinematically related faults. The eastern Santa Barbara Basin is deformed by large active reverse and thrust faults, and this area appears to be underlain regionally by the north-dipping Channel Islands thrust fault. These faults could produce moderate to strong earthquakes and destructive tsunamis. On the Malibu coast, earthquakes along offshore faults could have left-lateral-oblique focal mechanisms, and the Santa Monica Mountains thrust fault, which underlies the oblique faults, could give rise to large (M ??7) earthquakes. Offshore faults near Santa Monica Bay and the San Pedro shelf are likely to produce both strike-slip and thrust earthquakes along northwest-striking faults. In all areas, transverse structures, such as lateral ramps and tear faults, which crosscut the main faults, could segment earthquake rupture zones. ?? 2009 The Geological Society of America.

The Sparta Fault, Southern Greece: From segmentation and tectonic geomorphology to seismic hazard mapping and time dependent probabilities

NASA Astrophysics Data System (ADS)

Papanikolaοu, Ioannis D.; Roberts, Gerald P.; Deligiannakis, Georgios; Sakellariou, Athina; Vassilakis, Emmanuel

2013-06-01

The Sparta Fault system is a major structure approximately 64 km long that bounds the eastern flank of the Taygetos Mountain front (2407 m) and shapes the present-day Sparta basin. It was activated in 464 B.C., devastating the city of Sparta. This fault is examined and described in terms of its geometry, segmentation, drainage pattern and post-glacial throw, emphasising how these parameters vary along strike. Qualitative analysis of long profile catchments shows a significant difference in longitudinal convexity between the central and both the south and north parts of the fault system, leading to the conclusion of varying uplift rate along strike. Catchments are sensitive in differential uplift as it is observed by the calculated differences of the steepness index ksn between the outer (ksn < 83) and central parts (121 < ksn < 138) of the Sparta Fault along strike the fault system. Based on fault throw-rates and the bedrock geology a seismic hazard map has been constructed that extracts a locality specific long-term earthquake recurrence record. Based on this map the town of Sparta would experience a destructive event similar to that in 464 B.C. approximately every 1792 ± 458 years. Since no other major earthquake M ~ 7.0 has been generated by this system since 464 B.C., a future event could be imminent. As a result, not only time-independent but also time-dependent probabilities, which incorporate the concept of the seismic cycle, have been calculated for the town of Sparta, showing a considerably higher time-dependent probability of 3.0 ± 1.5% over the next 30 years compared to the time-independent probability of 1.66%. Half of the hanging wall area of the Sparta Fault can experience intensities ≥ IX, but belongs to the lowest category of seismic risk of the national seismic building code. On view of these relatively high calculated probabilities, a reassessment of the building code might be necessary.

The Sparta Fault, Southern Greece: From Segmentation and Tectonic Geomorphology to Seismic Hazard Mapping and Time Dependent Probabilities

NASA Astrophysics Data System (ADS)

Papanikolaou, Ioannis; Roberts, Gerald; Deligiannakis, Georgios; Sakellariou, Athina; Vassilakis, Emmanuel

2013-04-01

The Sparta Fault system is a major structure approximately 64 km long that bounds the eastern flank of the Taygetos Mountain front (2.407 m) and shapes the present-day Sparta basin. It was activated in 464 B.C., devastating the city of Sparta. This fault is examined and described in terms of its geometry, segmentation, drainage pattern and postglacial throw, emphasizing how these parameters vary along strike. Qualitative analysis of long profile catchments shows a significant difference in longitudinal convexity between the central and both the south and north parts of the fault system, leading to the conclusion of varying uplift rate along strike. Catchments are sensitive in differential uplift as it is observed by the calculated differences of the steepness index ksn between the outer (ksn<83) and central parts (121

Structural geology of the proposed site area for a high-level radioactive waste repository, Yucca Mountain, Nevada

USGS Publications Warehouse

Potter, C.J.; Day, W.C.; Sweetkind, D.S.; Dickerson, R.P.

2004-01-01

Geologic mapping and fracture studies have documented the fundamental patterns of joints and faults in the thick sequence of rhyolite tuffs at Yucca Mountain, Nevada, the proposed site of an underground repository for high-level radioactive waste. The largest structures are north-striking, block-bounding normal faults (with a subordinate left-lateral component) that divide the mountain into numerous 1-4-km-wide panels of gently east-dipping strata. Block-bounding faults, which underwent Quaternary movement as well as earlier Neogene movement, are linked by dominantly northwest-striking relay faults, especially in the more extended southern part of Yucca Mountain. Intrablock faults are commonly short and discontinuous, except those on the more intensely deformed margins of the blocks. Lithologic properties of the local tuff stratigraphy strongly control the mesoscale fracture network, and locally the fracture network has a strong influence on the nature of intrablock faulting. The least faulted part of Yucca Mountain is the north-central part, the site of the proposed repository. Although bounded by complex normal-fault systems, the 4-km-wide central block contains only sparse intrablock faults. Locally intense jointing appears to be strata-bound. The complexity of deformation and the magnitude of extension increase in all directions away from the proposed repository volume, especially in the southern part of the mountain where the intensity of deformation and the amount of vertical-axis rotation increase markedly. Block-bounding faults were active at Yucca Mountain during and after eruption of the 12.8-12.7 Ma Paintbrush Group, and significant motion on these faults postdated the 11.6 Ma Rainier Mesa Tuff. Diminished fault activity continued into Quaternary time. Roughly half of the stratal tilting in the site area occurred after 11.6 Ma, probably synchronous with the main pulse of vertical-axis rotation, which occurred between 11.6 and 11.45 Ma. Studies of sequential formation of tectonic joints, in the context of regional paleostress studies, indicate that north- and northwest-striking joint sets formed coevally with the main faulting episode during regional east-northeast-west-southwest extension and that a prominent northeast-striking joint set formed later, probably after 9 Ma. These structural analyses contribute to the understanding of several important issues at Yucca Mountain, including potential hydrologic pathways, seismic hazards, and fault-displacement hazards. ?? 2004 Geological Society of America.

78 FR 40264 - Agency Information Collection Activities: Requests for Comments; Clearance of Renewed Approval of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-03

...In accordance with the Paperwork Reduction Act of 1995, FAA invites public comments about our intention to request the Office of Management and Budget (OMB) approval to renew an information collection. The Federal Register Notice with a 60-day comment period soliciting comments on the following collection of information was published on April 19, 2013, vol. 78, no. 76, pages 23628-23629. Wildlife strike data are collected to develop standards and monitor hazards to aviation.

Geological-Seismological Evaluation of Earthquake Hazards at Franklin Falls Damsite, New Hampshire.

DTIC Science & Technology

1986-09-01

8217 the Corps records have been analyzed by Chang (1983) , Toksoz (1982) and Sauber (in press) (Table" 3, Fig. 6). The instrument at Seabrook was just...and others, 1983, Sauber , in press). A strike-slip motion was interpreted from the *. data, although two stations did not fit. The attitudes given by...the two possible solutions given by Sauber (in press) and using her dips are north 230 east, 680 southeast dip, left-lateral motion and north 700 west

FELIX-1.0: A finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation

NASA Astrophysics Data System (ADS)

Regnier, D.; Verrière, M.; Dubray, N.; Schunck, N.

2016-03-01

We describe the software package FELIX that solves the equations of the time-dependent generator coordinate method (TDGCM) in N-dimensions (N ≥ 1) under the Gaussian overlap approximation. The numerical resolution is based on the Galerkin finite element discretization of the collective space and the Crank-Nicolson scheme for time integration. The TDGCM solver is implemented entirely in C++. Several additional tools written in C++, Python or bash scripting language are also included for convenience. In this paper, the solver is tested with a series of benchmarks calculations. We also demonstrate the ability of our code to handle a realistic calculation of fission dynamics.

Charming Users into Scripting CIAO with Python

NASA Astrophysics Data System (ADS)

Burke, D. J.

2011-07-01

The Science Data Systems group of the Chandra X-ray Center provides a number of scripts and Python modules that extend the capabilities of CIAO. Experience in converting the existing scripts—written in a variety of languages such as bash, csh/tcsh, Perl and S-Lang—to Python, and conversations with users, led to the development of the ciao_contrib.runtool module. This allows users to easily run CIAO tools from Python scripts, and utilizes the metadata provided by the parameter-file system to create an API that provides the flexibility and safety guarantees of the command-line. The module is provided to the user community and is being used within our group to create new scripts.

Film at Fall Meeting: Do-it-yourself flicks, Richard Alley preview

NASA Astrophysics Data System (ADS)

Adams, Mary Catherine

2011-11-01

Have you ever wished science had Hollywood star power? On Tuesday evening, 6 December, watch short science films and hear Hollywood filmmakers give advice to AGU scientists about these short films. Oceanographer-turned-filmmaker Randy Olson will host AGU's "The S Factor" video workshop along with screenwriter Sean Hood, cowriter of Halloween: Resurrection and the 2011 remake ofConan the Barbarian, and Jason Ensler, co-producer-director of TNT's Franklin & Bash. Olson is writer-director of the documentaries Flock of Dodos and Sizzle: A Global Warming Comedy and author of Don't Be Such a Scientist: Talking Substance in an Age of Style. The workshop starts at 7:00 P.M. in Moscone South, Room 300.

Comparing Data from the Poisons Information Centre with Employers' Accident Reports Reveal Under-Recognized Hazards at the Workplace.

PubMed

Schenk, Linda; Öberg, Mattias

2018-05-28

Records of injuries and incidents provide an important basis for injury prevention related to hazardous substances at the workplace. The present study aimed to review available data on injuries and incidents involving hazardous substances and investigate how data from the Poisons Information Centre could complement the records of the Swedish Work Environment Authority. We found two major obstacles for using injury/incident data based on employers' mandatory reporting. First, it was not possible to quickly and reliably identify injuries caused by hazardous substances, and second, data identifying substances or products are not systematically included. For two out of five investigated injuries with lost working days likely due to chemical injuries, we could not identify substances and/or products involved. The records based on calls to the Poisons Information Centre allow better understanding of chemical hazards and products. Besides the large share of unidentified chemical hazards in the injury statistics, the most striking difference was found for cleaning agents. Cleaning agents were implicated in one-third of the occupational cases that the consulting Poisons Information Centre expert judged to pose a major risk and in need of immediate healthcare. Only one in 10 injuries with lost days reported by employers was related to this type of product. The identification of exposures and symptoms by the Poisons Information Centre allow recognition of chemicals with problematic occupational uses. Hence, these records may serve as an important complement to official injury statistics related to incidents with hazardous substances at work.

A recent Mw 4.3 earthquake proving activity of a shallow strike-slip fault in the northern part of the Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Ezzelarab, Mohamed; Ebraheem, Mohamed O.; Zahradník, Jiří

2018-03-01

The Mw 4.3 earthquake of September 2015 is the first felt earthquake since 1900 A.D in the northern part of the Western Desert, Egypt, south of the El-Alamein City. The available waveform data observed at epicentral distances 52-391 km was collected and carefully evaluated. Nine broad-band stations were selected to invert full waveforms for the centroid position (horizontal and vertical) and for the focal mechanism solution. The first-arrival travel times, polarities and low-frequency full waveforms (0.03-0.08 Hz) are consistently explained in this paper as caused by a shallow source of the strike-slip mechanism. This finding indicates causal relation of this earthquake to the W-E trending South El-Alamein fault, which developed in Late Cretaceous as dextral strike slip fault. Recent activity of this fault, proven by the studied rare earthquake, is of fundamental importance for future seismic hazard evaluations, underlined by proximity (∼65 km) of the source zone to the first nuclear power plant planned site in Egypt. Safe exploration and possible future exploitation of hydrocarbon reserves, reported around El-Alamein fault in the last decade, cannot be made without considering the seismic potential of this fault.

Preparing for radiological assessments in the event of a tornado strike at Argonne National Lab. -East

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goodkind, M.E.; Klimczak, C.A.; Munyon, W.J.

1993-01-01

Argonne National Laboratory-East (ANL) is a Department of Energy (DOE)-owned, contractor-operated national laboratory located 22 miles southwest of downtown Chicago on a wooded, 1700-acre site. The principal nuclear facilities at ANL include a large fast neutron source (Intense Pulse Neutron Source) in which high-energy protons strike a uranium target to produce neutrons for research studies; [sup 60]Co irradiation sources; chemical and metallurgical plutonium laboratories, some of which are currently being decommissioned; several large hot cell facilities designed for work with multicurie quantities of actinide elements and irradiated reactor fuel materials; a few small research reactors currently in different phases ofmore » being decommissioned; and a variety of research laboratories handling many different sources in various chemical and physical forms. The hazards analysis for the ANL site shows that tornado strikes are a serious threat. The site has been struck twice in the past 20 yr, receiving only minor building damage and no release of radioactivity to the environment. Although radioactive materials in general are handled in areas that provide good tornado protection, ANL is prepared to address the problems that would occur should there be a loss of control of radioactive materials due to severe building damage.« less

The flow structure of pyroclastic density currents: evidence from particle models and large-scale experiments

NASA Astrophysics Data System (ADS)

Dellino, Pierfrancesco; Büttner, Ralf; Dioguardi, Fabio; Doronzo, Domenico Maria; La Volpe, Luigi; Mele, Daniela; Sonder, Ingo; Sulpizio, Roberto; Zimanowski, Bernd

2010-05-01

Pyroclastic flows are ground hugging, hot, gas-particle flows. They represent the most hazardous events of explosive volcanism, one striking example being the famous historical eruption of Pompeii (AD 79) at Vesuvius. Much of our knowledge on the mechanics of pyroclastic flows comes from theoretical models and numerical simulations. Valuable data are also stored in the geological record of past eruptions, i.e. the particles contained in pyroclastic deposits, but they are rarely used for quantifying the destructive potential of pyroclastic flows. In this paper, by means of experiments, we validate a model that is based on data from pyroclastic deposits. It allows the reconstruction of the current's fluid-dynamic behaviour. We show that our model results in likely values of dynamic pressure and particle volumetric concentration, and allows quantifying the hazard potential of pyroclastic flows.

North south asymmetry in the photospheric and coronal magnetic fields observed by different instruments

NASA Astrophysics Data System (ADS)

Virtanen, Ilpo; Mursula, Kalevi

2015-04-01

Several recent studies have shown that the solar and heliospheric magnetic fields are north-south asymmetric. The southward shift of the Heliospheric current sheet (HCS) (the so-called bashful ballerina phenomenon) is a persistent pattern, which occurs typically for about three years during the late declining phase of solar cycle. We study here the hemispherical asymmetry in the photospheric and coronal magnetic fields using Wilcox Solar Observatory (WSO), Mount Wilson, Kitt Peak, Solis, SOHO/MDI and SDO/HMI measurements of the photospheric magnetic field since the 1970s and the potential field source surface (PFSS) model.Multipole analysis of the photospheric magnetic field has shown that the bashful ballerina phenomenon is a consequence of g20 quadrupole term, which is oppositely signed to the dipole moment. We find that, at least during the four recent solar cycles, the g20 reflects the larger magnitude of the southern polar field during a few years in the declining phase of the cycle. Although the overall magnetic activity during the full solar cycle is not very different in the two hemispheres, the temporal distribution of activity is different, contributing to the asymmetry. The used data sets are in general in a good agreement with each other, but there are some significant deviations, especially in WSO data. Also, the data from Kitt Peak 512 channel magnetograph is known to suffer from zero level errors.We also note that the lowest harmonic coefficients do not scale with the overall magnitude in photospheric synoptic magnetic maps. Scaling factors based on histogram techniques can be as large as 10 (from Wilcox to HMI), but the corresponding difference in dipole strength is typically less than two. This is because the polar field has a dominant contribution to the dipole and quadrupole components. This should be noted, e.g., when using synoptic maps as input for coronal models.

Ground-penetrating radar investigation of active faults along the Dead Sea Transform and implications for seismic hazards within the city of Aqaba, Jordan

NASA Astrophysics Data System (ADS)

Slater, Lee; Niemi, Tina M.

2003-06-01

Ground-penetrating radar (GPR) was used in an effort to locate a major active fault that traverses Aqaba City, Jordan. Measurements over an exposed (trenched) cross fault outside of the city identify a radar signature consisting of linear events and horizontal offset/flexured reflectors both showing a geometric correlation with two known faults at a control site. The asymmetric linear events are consistent with dipping planar reflectors matching the known direction of dip of the faults. However, other observations regarding this radar signature render the mechanism generating these events more complex and uncertain. GPR measurements in Aqaba City were limited to vacant lots. Seven GPR profiles were conducted approximately perpendicular to the assumed strike of the fault zone, based on regional geological evidence. A radar response very similar to that obtained over the cross fault was observed on five of the profiles in Aqaba City, although the response is weaker than that obtained at the control site. The positions of the identified responses form a near straight line with a strike of 45°. Although subsurface verification of the fault by trenching within the city is needed, the geophysical evidence for fault zone location is strong. The location of the interpreted fault zone relative to emergency services, military bases, commercial properties, and residential areas is defined to within a few meters. This study has significant implications for seismic hazard analysis in this tectonically active and heavily populated region.

Using expert opinion surveys to rank threats to endangered species: a case study with sea turtles.

PubMed

Donlan, C Josh; Wingfield, Dana K; Crowder, Larry B; Wilcox, Chris

2010-12-01

Little is known about how specific anthropogenic hazards affect the biology of organisms. Quantifying the effect of regional hazards is particularly challenging for species such as sea turtles because they are migratory, difficult to study, long lived, and face multiple anthropogenic threats. Expert elicitation, a technique used to synthesize opinions of experts while assessing uncertainty around those views, has been in use for several decades in the social science and risk assessment sectors. We conducted an internet-based survey to quantify expert opinion on the relative magnitude of anthropogenic hazards to sea turtle populations at the regional level. Fisheries bycatch and coastal development were most often ranked as the top hazards to sea turtle species in a geographic region. Nest predation and direct take followed as the second and third greatest threats, respectively. Survey results suggest most experts believe sea turtles are threatened by multiple factors, including substantial at-sea threats such as fisheries bycatch. Resources invested by the sea turtle community, however, appear biased toward terrestrial-based impacts. Results from the survey are useful for conservation planning because they provide estimates of relative impacts of hazards on sea turtles and a measure of consensus on the magnitude of those impacts among researchers and practitioners. Our survey results also revealed patterns of expert bias, which we controlled for in our analysis. Respondents with no experience with respect to a sea turtle species tended to rank hazards affecting that sea turtle species higher than respondents with experience. A more-striking pattern was with hazard-based expertise: the more experience a respondent had with a specific hazard, the higher the respondent scored the impact of that hazard on sea turtle populations. Bias-controlled expert opinion surveys focused on threatened species and their hazards can help guide and expedite species recovery plans. © 2010 Society for Conservation Biology.

Atmospheric Electrical Modeling in Support of the NASA F-106 Storm Hazards Project

NASA Technical Reports Server (NTRS)

Helsdon, John H., Jr.

1988-01-01

A recently developed storm electrification model (SEM) is used to investigate the operating environment of the F-106 airplane during the NASA Storm Hazards Project. The model is 2-D, time dependent and uses a bulkwater microphysical parameterization scheme. Electric charges and fields are included, and the model is fully coupled dynamically, microphysically and electrically. One flight showed that a high electric field was developed at the aircraft's operating altitude (28 kft) and that a strong electric field would also be found below 20 kft; however, this low-altitude, high-field region was associated with the presence of small hail, posing a hazard to the aircraft. An operational procedure to increase the frequency of low-altitude lightning strikes was suggested. To further the understanding of lightning within the cloud environment, a parameterization of the lightning process was included in the SEM. It accounted for the initiation, propagation, termination, and charge redistribution associated with an intracloud discharge. Finally, a randomized lightning propagation scheme was developed, and the effects of cloud particles on the initiation of lightning investigated.

Study on the Evaluation Method for Fault Displacement: Probabilistic Approach Based on Japanese Earthquake Rupture Data - Principal fault displacements -

NASA Astrophysics Data System (ADS)

Kitada, N.; Inoue, N.; Tonagi, M.

2016-12-01

The purpose of Probabilistic Fault Displacement Hazard Analysis (PFDHA) is estimate fault displacement values and its extent of the impact. There are two types of fault displacement related to the earthquake fault: principal fault displacement and distributed fault displacement. Distributed fault displacement should be evaluated in important facilities, such as Nuclear Installations. PFDHA estimates principal fault and distributed fault displacement. For estimation, PFDHA uses distance-displacement functions, which are constructed from field measurement data. We constructed slip distance relation of principal fault displacement based on Japanese strike and reverse slip earthquakes in order to apply to Japan area that of subduction field. However, observed displacement data are sparse, especially reverse faults. Takao et al. (2013) tried to estimate the relation using all type fault systems (reverse fault and strike slip fault). After Takao et al. (2013), several inland earthquakes were occurred in Japan, so in this time, we try to estimate distance-displacement functions each strike slip fault type and reverse fault type especially add new fault displacement data set. To normalized slip function data, several criteria were provided by several researchers. We normalized principal fault displacement data based on several methods and compared slip-distance functions. The normalized by total length of Japanese reverse fault data did not show particular trend slip distance relation. In the case of segmented data, the slip-distance relationship indicated similar trend as strike slip faults. We will also discuss the relation between principal fault displacement distributions with source fault character. According to slip distribution function (Petersen et al., 2011), strike slip fault type shows the ratio of normalized displacement are decreased toward to the edge of fault. However, the data set of Japanese strike slip fault data not so decrease in the end of the fault. This result indicates that the fault displacement is difficult to appear at the edge of the fault displacement in Japan. This research was part of the 2014-2015 research project `Development of evaluating method for fault displacement` by the Secretariat of Nuclear Regulation Authority (NRA), Japan.

Industrial accidents triggered by lightning.

PubMed

Renni, Elisabetta; Krausmann, Elisabeth; Cozzani, Valerio

2010-12-15

Natural disasters can cause major accidents in chemical facilities where they can lead to the release of hazardous materials which in turn can result in fires, explosions or toxic dispersion. Lightning strikes are the most frequent cause of major accidents triggered by natural events. In order to contribute towards the development of a quantitative approach for assessing lightning risk at industrial facilities, lightning-triggered accident case histories were retrieved from the major industrial accident databases and analysed to extract information on types of vulnerable equipment, failure dynamics and damage states, as well as on the final consequences of the event. The most vulnerable category of equipment is storage tanks. Lightning damage is incurred by immediate ignition, electrical and electronic systems failure or structural damage with subsequent release. Toxic releases and tank fires tend to be the most common scenarios associated with lightning strikes. Oil, diesel and gasoline are the substances most frequently released during lightning-triggered Natech accidents. Copyright © 2010 Elsevier B.V. All rights reserved.

Stress changes from the 2008 Wenchuan earthquake and increased hazard in the Sichuan basin

USGS Publications Warehouse

Parsons, T.; Ji, C.; Kirby, E.

2008-01-01

On 12 May 2008, the devastating magnitude 7.9 (Wenchuan) earthquake struck the eastern edge of the Tibetan plateau, collapsing buildings and killing thousands in major cities aligned along the western Sichuan basin in China. After such a large-magnitude earthquake, rearrangement of stresses in the crust commonly leads to subsequent damaging earthquakes. The mainshock of the 12 May earthquake ruptured with as much as 9 m of slip along the boundary between the Longmen Shan and Sichuan basin, and demonstrated the complex strike-slip and thrust motion that characterizes the region. The Sichuan basin and surroundings are also crossed by other active strike-slip and thrust faults. Here we present calculations of the coseismic stress changes that resulted from the 12 May event using models of those faults, and show that many indicate significant stress increases. Rapid mapping of such stress changes can help to locate fault sections with relatively higher odds of producing large aftershocks. ??2008 Macmillan Publishers Limited. All rights reserved.

Three-armed rifts or masked radial pattern of eruptive fissures? The intriguing case of El Hierro volcano (Canary Islands)

NASA Astrophysics Data System (ADS)

Becerril, L.; Galindo, I.; Martí, J.; Gudmundsson, A.

2015-04-01

Using new surface structural data as well as subsurface structural data obtained from seventeen water galleries, we provide a comprehensive model of the volcano-tectonic evolution of El Hierro (Canary Islands). We have identified, measured and analysed more than 1700 volcano-structural elements including vents, eruptive fissures, dykes and faults. The new data provide important information on the main structural patterns of the island and on its stress and strain fields, all of which are crucial for reliable hazard assessments. We conducted temporal and spatial analyses of the main structural elements, focusing on their relative age and association with the three main cycles in the construction of the island: the Tiñor Edifice, the El Golfo-Las Playas Edifice, and the Rift Volcanism. A radial strike distribution, which can be related to constructive episodes, is observed in the on-land structures. A similar strike distribution is seen in the submarine eruptive fissures, which are radial with respect to the centre of the island. However, the volcano-structural elements identified onshore and reflecting the entire volcano-tectonic evolution of the island also show a predominant NE-SW strike, which coincides with the main regional trend of the Canary archipelago as a whole. Two other dominant directions of structural elements, N-S and WNW-ESE, are evident from the establishment of the El Golfo-Las Playas edifice, during the second constructive cycle. We suggest that the radial-striking structures reflect comparatively uniform stress fields during the constructive episodes, mainly conditioned by the combination of overburden pressure, gravitational spreading, and magma-induced stresses in each of the volcanic edifices. By contrast, in the shallower parts of the edifice the NE-SW, N-S and WNW-ESE-striking structures reflect local stress fields related to the formation of mega-landslides and masking the general and regional radial patterns.

The enigma of the Arthur's Pass, New Zealand, earthquake 1. Reconciling a variety of data for an unusual earthquake sequence

USGS Publications Warehouse

Abercrombie, R.E.; Webb, T.H.; Robinson, R.; McGinty, P.J.; Mori, J.J.; Beavan, R.J.

2000-01-01

The 1994 Arthur's Pass earthquake (Mw6.7) is the largest in a recent sequence of earthquakes in the central South Island, New Zealand. No surface rupture was observed the aftershock distribution was complex, and routine methods of obtaining the faulting orientation of this earthquake proved contradictory. We use a range of data and techniques to obtain our preferred solution, which has a centroid depth of 5 km, Mo=1.3??1019 N m, and a strike, dip, and rake of 221??, 47??, 112??, respectively. Discrepancies between this solution and the Harvard centroid moment tensor, together with the Global Positioning System (GPS) observations and unusual aftershock distribution, suggest that the rupture may not have occurred on a planar fault. A second, strike slip, subevent on a more northerly striking plane is suggested by these data but neither the body wave modeling nor regional broadband recordings show any complexity or late subevents. We relocate the aftershocks using both one-dimensional and three-dimensional velocity inversions. The depth range of the aftershocks (1-10 km) agrees well with the preferred mainshock centroid depth. The aftershocks near the hypocenter suggest a structure dipping toward the NW, which we interpret to be the mainshock fault plane. This structure and the Harper fault, ???15 km to the south appear to have acted as boundaries to the extensive aftershock zone trending NNW-SSE Most of the ML???5 aftershocks, including the two largest (ML6.1 and ML5.7), clustered near the Harper fault and have strike slip mechanisms consistent with motion on this fault and its conjugates. Forward modeling of the GPS data suggests that a reverse slip mainshock, combined with strike slip aftershock faulting in the south, is able to match the observed displacements. The occurrence of this earthquake sequence implies that the level of seismic hazard in the central South Island is greater than previous estimates. Copyright 2000 by the American Geophysical Union.

Bermuda earthquake of March 24, 1978: A significant oceanic intraplate event

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stewart, G.S.; Helmberger, D.V.

1981-08-10

The Bremuda earthquake (Mapprox.6) occured near the westerly extension of the Kane Fracture Zone roughly 370 km southwest of the island of Bermuda. It is one of the largest oceanic intraplate earthquakes to occur off the eastern coast of North America. Because of its size and location, it has provided an excellent set of WWSSN body waves. They can be used to infer its depth and faulting parameters by waveform modeling techniques. The results indicate a north-northwest striking thrust mechanism (strike = N20 /sup 0/W, dip = 42 /sup 0/NE, rake = 90/sup 0/) with the hypocenter located at amore » depth of 11 km, which for an oceanic crust places it predominantly in the mantle. The event had a seismic moment of 3.4 x 10/sup 25/ dyne cm, and its time history was modeled with a symmetric trapezoidal time function 3 s in duration. The north-northwest strike of the event is in good agreement with the bathymetry of the area, the epicenter being close to the southwestern edge of the Bermuda Rise. The strike of the event is also close to that of the inferred extensions of the present ridge fracture zones in the region. The strike of the event is also close to that of the inferred extensions of the present ridge fracture zones in the region. The presence of fracture zones is indicative of local weak zones in the lithosphere. The Bermuda earthquake most likely is associated with one of these zones of weakness and is the result of the application of present day stress imposed on the region by the North American plate in the direction of its absolute motion. This is an important event in terms of understanding and estimating seismic hazard on the eastern seaboard of North America.« less

A first hazard analysis of the Harrat Ash Shamah volcanic field, Syria-Jordan Borderline

NASA Astrophysics Data System (ADS)

Cagnan, Zehra; Akkar, Sinan; Moghimi, Saed

2017-04-01

The northernmost part of the Saudi Cenozoic Volcanic Fields, the 100,000 km2 Harrat Ash Shamah has hosted some of the most recent volcanic eruptions along the Syria-Jordan borderline. With rapid growth of the cities in this region, exposure to any potential renewed volcanism increased considerably. We present here a first-order probabilistic hazard analysis related to new vent formation and subsequent lava flow from Harrat Ash Shamah. The 733 visible eruption vent sites were utilized to develop a probability density function for new eruption sites using Gaussian kernel smoothing. This revealed a NNW striking zone of high spatial hazard surrounding the cities Amman and Irbid in Jordan. The temporal eruption recurrence rate is estimated to be approximately one vent per 3500 years, but the temporal record of the field is so poorly constrained that the lower and upper bounds for the recurrence interval are 17,700 yrs and 70 yrs, respectively. A Poisson temporal model is employed within the scope of this study. In order to treat the uncertainties associated with the spatio-temporal models as well as size of the area affected by the lava flow, the logic tree approach is adopted. For the Syria-Jordan borderline, the spatial variation of volcanic hazard is computed as well as uncertainty associated with these estimates.

ROSSTEP v1.3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allevato, Adam

2016-07-21

ROSSTEP is a system for sequentially running roslaunch, rosnode, and bash scripts automatically, for use in Robot Operating System (ROS) applications. The system consists of YAML files which define actions and conditions. A python file parses the code and runs actions sequentially using the sys and subprocess python modules. Between actions, it uses various ROS-based code to check conditions required to proceed, and only moves on to the next action when all the necessary conditions have been met. Included is rosstep-creator, a QT application designed to create the YAML files required for ROSSTEP. It has a nearly one-to-one mapping frommore » interface elements to YAML output, and serves as a convenient GUI for working with the ROSSTEP system.« less

FELIX-1.0: A finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation

DOE PAGES

Regnier, D.; Verriere, M.; Dubray, N.; ...

2015-11-30

In this study, we describe the software package FELIX that solves the equations of the time-dependent generator coordinate method (TDGCM) in NN-dimensions (N ≥ 1) under the Gaussian overlap approximation. The numerical resolution is based on the Galerkin finite element discretization of the collective space and the Crank–Nicolson scheme for time integration. The TDGCM solver is implemented entirely in C++. Several additional tools written in C++, Python or bash scripting language are also included for convenience. In this paper, the solver is tested with a series of benchmarks calculations. We also demonstrate the ability of our code to handle amore » realistic calculation of fission dynamics.« less

BaHaMAS A Bash Handler to Monitor and Administrate Simulations

NASA Astrophysics Data System (ADS)

Sciarra, Alessandro

2018-03-01

Numerical QCD is often extremely resource demanding and it is not rare to run hundreds of simulations at the same time. Each of these can last for days or even months and it typically requires a job-script file as well as an input file with the physical parameters for the application to be run. Moreover, some monitoring operations (i.e. copying, moving, deleting or modifying files, resume crashed jobs, etc.) are often required to guarantee that the final statistics is correctly accumulated. Proceeding manually in handling simulations is probably the most error-prone way and it is deadly uncomfortable and inefficient! BaHaMAS was developed and successfully used in the last years as a tool to automatically monitor and administrate simulations.

Research and Development of Energetic Ionic Liquids. Next Generation Energetic Materials Striking a Balance between Performance, Insensitivity, and Environmental Sustainability

DTIC Science & Technology

2011-12-01

thermal and catalytic ignition flight qualified and flown (PRISMA) Distribution A: Public Release, Distribution unlimited. AF - M315E is US Air Force IL...for Space Propulsion, Noordwijk, The Netherlands, 20-22 June 2001. 6 Toxicity Assessment of AF - M315E Toxicity Testing Results PROPERTY AF - M315E ...Distribution Unlimited. 8 Much Effort Required in Small- Scale Safety/Hazard Evaluations Propellant AF - M315E * LMP-103S** Unconfined Burn Test 1 and 3: No

The meteorite impact-induced tsunami hazard.

PubMed

Wünnemann, K; Weiss, R

2015-10-28

When a cosmic object strikes the Earth, it most probably falls into an ocean. Depending on the impact energy and the depth of the ocean, a large amount of water is displaced, forming a temporary crater in the water column. Large tsunami-like waves originate from the collapse of the cavity in the water and the ejecta splash. Because of the far-reaching destructive consequences of such waves, an oceanic impact has been suggested to be more severe than a similar-sized impact on land; in other words, oceanic impacts may punch over their weight. This review paper summarizes the process of impact-induced wave generation and subsequent propagation, whether the wave characteristic differs from tsunamis generated by other classical mechanisms, and what methods have been applied to quantify the consequences of an oceanic impact. Finally, the impact-induced tsunami hazard will be evaluated by means of the Eltanin impact event. © 2015 The Author(s).

Infrasonic crackle and supersonic jet noise from the eruption of Nabro Volcano, Eritrea

NASA Astrophysics Data System (ADS)

Fee, David; Matoza, Robin S.; Gee, Kent L.; Neilsen, Tracianne B.; Ogden, Darcy E.

2013-08-01

The lowermost portion of an explosive volcanic eruption column is considered a momentum-driven jet. Understanding volcanic jets is critical for determining eruption column dynamics and mitigating volcanic hazards; however, volcanic jets are inherently difficult to observe due to their violence and opacity. Infrasound from the 2011 eruption of Nabro Volcano, Eritrea has waveform features highly similar to the "crackle" phenomenon uniquely produced by man-made supersonic jet engines and rockets and is characterized by repeated asymmetric compressions followed by weaker, gradual rarefactions. This infrasonic crackle indicates that infrasound source mechanisms in sustained volcanic eruptions are strikingly similar to jet noise sources from heated, supersonic jet engines and rockets, suggesting that volcanologists can utilize the modeling and physical understandings of man-made jets to understand volcanic jets. The unique, distinctive infrasonic crackle from Nabro highlights the use of infrasound to remotely detect and characterize hazardous eruptions and its potential to determine volcanic jet parameters.

Flooding: A unique year

USGS Publications Warehouse

Putnam, A.L.

1984-01-01

Floods have been and continue to be one of the most destructive hazards facing the people of the United States. Of all the natural hazards, floods are the most widespread and the most ruinous to life and property. Today, floods are a greater menace to our welfare than ever before because we live in large numbers near water and have developed a complex reliance upon it. From large rivers to country creeks, from mountain rills to the trickles that occasionally dampen otherwise arid wastelands, every stream in the United States is subject to flooding at some time. Floods strike in myriad forms, including sea surges driven by wild winds or tsunamis churned into fury by seismic activity. By far the most frequent, however, standing in a class by themselves, are the inland, freshwater floods that are caused by rain, by melting snow and ice, or by the bursting of structures that man has erected to protect himself and his belongings from angry waters.

Abrupt along-strike change in tectonic style: San Andreas fault zone, San Francisco Peninsula

USGS Publications Warehouse

Zoback, M.L.; Jachens, R.C.; Olson, J.A.

1999-01-01

Seismicity and high-resolution aeromagnetic data are used to define an abrupt change from compressional to extensional tectonism within a 10- to 15-km-wide zone along the San Andreas fault on the San Francisco Peninsula and offshore from the Golden Gate. This 100-km-long section of the San Andreas fault includes the hypocenter of the Mw = 7.8 1906 San Francisco earthquake as well as the highest level of persistent microseismicity along that ???470-km-long rupture. We define two distinct zones of deformation along this stretch of the fault using well-constrained relocations of all post-1969 earthquakes based a joint one-dimensional velocity/hypocenter inversion and a redetermination of focal mechanisms. The southern zone is characterized by thrust- and reverse-faulting focal mechanisms with NE trending P axes that indicate "fault-normal" compression in 7- to 10-km-wide zones of deformation on both sides of the San Andreas fault. A 1- to 2-km-wide vertical zone beneath the surface trace of the San Andreas is characterized by its almost complete lack of seismicity. The compressional deformation is consistent with the young, high topography of the Santa Cruz Mountains/Coast Ranges as the San Andreas fault makes a broad restraining left bend (???10??) through the southernmost peninsula. A zone of seismic quiescence ???15 km long separates this compressional zone to the south from a zone of combined normal-faulting and strike-slip-faulting focal mechanisms (including a ML = 5.3 earthquake in 1957) on the northernmost peninsula and offshore on the Golden Gate platform. Both linear pseudo-gravity gradients, calculated from the aeromagnetic data, and seismic reflection data indicate that the San Andreas fault makes an abrupt ???3-km right step less than 5 km offshore in this northern zone. A similar right-stepping (dilatational) geometry is also observed for the subparallel San Gregorio fault offshore. Persistent seismicity and extensional tectonism occur within the San Andreas right stepover region and at least 15 km along-strike both to the SE and NW. The 1906 San Francisco earthquake may have nucleated within the San Andreas right stepover, which may help explain the bilateral nature of rupture of this event. Our analysis suggests two seismic hazards for the San Francisco Peninsula in addition to the hazard associated with a M = 7 to 8 strike-slip earthquake along the San Andreas fault: the potential for a M ??? 6 normal-faulting earthquake just 5-8 km west of San Francisco and a M = 6+ thrust faulting event in the southern peninsula.

Marine geology and earthquake hazards of the San Pedro Shelf region, southern California

USGS Publications Warehouse

Fisher, Michael A.; Normark, William R.; Langenheim, V.E.; Calvert, Andrew J.; Sliter, Ray

2004-01-01

High-resolution seismic-reflection data have been com- bined with a variety of other geophysical and geological data to interpret the offshore structure and earthquake hazards of the San Pedro Shelf, near Los Angeles, California. Prominent structures investigated include the Wilmington Graben, the Palos Verdes Fault Zone, various faults below the western part of the shelf and slope, and the deep-water San Pedro Basin. The structure of the Palos Verdes Fault Zone changes mark- edly southeastward across the San Pedro Shelf and slope. Under the northern part of the shelf, this fault zone includes several strands, but the main strand dips west and is probably an oblique-slip fault. Under the slope, this fault zone con- sists of several fault strands having normal separation, most of which dip moderately east. To the southeast near Lasuen Knoll, the Palos Verdes Fault Zone locally is a low-angle fault that dips east, but elsewhere near this knoll the fault appears to dip steeply. Fresh sea-floor scarps near Lasuen Knoll indi- cate recent fault movement. The observed regional structural variation along the Palos Verdes Fault Zone is explained as the result of changes in strike and fault geometry along a master strike-slip fault at depth. The shallow summit and possible wavecut terraces on Lasuen knoll indicate subaerial exposure during the last sea-level lowstand. Modeling of aeromagnetic data indicates the presence of a large magnetic body under the western part of the San Pedro Shelf and upper slope. This is interpreted to be a thick body of basalt of Miocene(?) age. Reflective sedimentary rocks overlying the basalt are tightly folded, whereas folds in sedimentary rocks east of the basalt have longer wavelengths. This difference might mean that the basalt was more competent during folding than the encasing sedimentary rocks. West of the Palos Verdes Fault Zone, other northwest-striking faults deform the outer shelf and slope. Evidence for recent movement along these faults is equivocal, because age dates on deformed or offset sediment are lacking.

Insights into the relationship between surface and subsurface activity from mechanical modeling of the 1992 Landers M7.3 earthquake

NASA Astrophysics Data System (ADS)

Madden, E. H.; Pollard, D. D.

2009-12-01

Multi-fault, strike-slip earthquakes have proved difficult to incorporate into seismic hazard analyses due to the difficulty of determining the probability of these ruptures, despite collection of extensive data associated with such events. Modeling the mechanical behavior of these complex ruptures contributes to a better understanding of their occurrence by elucidating the relationship between surface and subsurface earthquake activity along transform faults. This insight is especially important for hazard mitigation, as multi-fault systems can produce earthquakes larger than those associated with any one fault involved. We present a linear elastic, quasi-static model of the southern portion of the 28 June 1992 Landers earthquake built in the boundary element software program Poly3D. This event did not rupture the extent of any one previously mapped fault, but trended 80km N and NW across segments of five sub-parallel, N-S and NW-SE striking faults. At M7.3, the earthquake was larger than the potential earthquakes associated with the individual faults that ruptured. The model extends from the Johnson Valley Fault, across the Landers-Kickapoo Fault, to the Homestead Valley Fault, using data associated with a six-week time period following the mainshock. It honors the complex surface deformation associated with this earthquake, which was well exposed in the desert environment and mapped extensively in the field and from aerial photos in the days immediately following the earthquake. Thus, the model incorporates the non-linearity and segmentation of the main rupture traces, the irregularity of fault slip distributions, and the associated secondary structures such as strike-slip splays and thrust faults. Interferometric Synthetic Aperture Radar (InSAR) images of the Landers event provided the first satellite images of ground deformation caused by a single seismic event and provide constraints on off-fault surface displacement in this six-week period. Insight is gained by comparing the density, magnitudes and focal plane orientations of relocated aftershocks for this time frame with the magnitude and orientation of planes of maximum Coulomb shear stress around the fault planes at depth.

Gravity and magnetic expression of the San Leandro gabbro with implications for the geometry and evolution of the Hayward Fault zone, northern California

USGS Publications Warehouse

Ponce, D.A.; Hildenbrand, T.G.; Jachens, R.C.

2003-01-01

The Hayward Fault, one of the most hazardous faults in northern California, trends north-northwest and extends for about 90 km along the eastern San Francisco Bay region. At numerous locations along its length, distinct and elongate gravity and magnetic anomalies correlate with mapped mafic and ultramafic rocks. The most prominent of these anomalies reflects the 16-km-long San Leandro gabbroic block. Inversion of magnetic and gravity data constrained with physical property measurements is used to define the subsurface extent of the San Leandro gabbro body and to speculate on its origin and relationship to the Hayward Fault Zone. Modeling indicates that the San Leandro gabbro body is about 3 km wide, dips about 75??-80?? northeast, and extends to a depth of at least 6 km. One of the most striking results of the modeling, which was performed independently of seismicity data, is that accurately relocated seismicity is concentrated along the western edge or stratigraphically lower bounding surface of the San Leandro gabbro. The western boundary of the San Leandro gabbro block is the base of an incomplete ophiolite sequence and represented at one time, a low-angle roof thrust related to the tectonic wedging of the Franciscan Complex. After repeated episodes of extension and attenuation, the roof thrust of this tectonic wedge was rotated to near vertical, and in places, the strike-slip Hayward Fault probably reactivated or preferentially followed this pre-existing feature. Because earthquakes concentrate near the edge of the San Leandro gabbro but tend to avoid its interior, we qualitatively explore mechanical models to explain how this massive igneous block may influence the distribution of stress. The microseismicity cluster along the western flank of the San Leandro gabbro leads us to suggest that this stressed volume may be the site of future moderate to large earthquakes. Improved understanding of the three-dimensional geometry and physical properties along the Hayward Fault will provide additional constraints on seismic hazard probability, earthquake modeling, and fault interactions that are applicable to other major strike-slip faults around the world.

Home safety measures and the risk of unintentional injury among young children: a multicentre case–control study

PubMed Central

LeBlanc, John C.; Pless, I. Barry; King, W. James; Bawden, Harry; Bernard-Bonnin, Anne-Claude; Klassen, Terry; Tenenbein, Milton

2006-01-01

Background Young children may sustain injuries when exposed to certain hazards in the home. To better understand the relation between several childproofing strategies and the risk of injuries to children in the home, we undertook a multicentre case–control study in which we compared hazards in the homes of children with and without injuries. Methods We conducted this case-control study using records from 5 pediatric hospital emergency departments for the 2-year period 1995–1996. The 351 case subjects were children aged 7 years and less who presented with injuries from falls, burns or scalds, ingestions or choking. The matched control subjects were children who presented during the same period with acute non-injury-related conditions. A home visitor, blinded to case-control status, assessed 19 injury hazards at the children's homes. Results Hazards found in the homes included baby walkers (21% of homes with infants), no functioning smoke alarm (17% of homes) and no fire extinguisher (51% of homes). Cases did not differ from controls in the mean proportion of home hazards. After controlling for siblings, maternal education and employment, we found that cases differed from controls for 5 hazards: the presence of a baby walker (odds ratio [OR] 9.0, 95% confidence interval [CI] 1.1–71.0), the presence of choking hazards within a child's reach (OR 2.0, 95% CI 1.0–3.7), no child-resistant lids in bathroom (OR 1.6, 95% CI 1.0–2.5), no smoke alarm (OR 3.2, 95% CI 1.4–7.7) and no functioning smoke alarm (OR 1.7, 95% CI 1.0–2.8). Interpretation Homes of children with injuries differed from those of children without injuries in the proportions of specific hazards for falls, choking, poisoning and burns, with a striking difference noted for the presence of a baby walker. In addition to counselling parents about specific hazards, clinicians should consider that the presence of some hazards may indicate an increased risk for home injuries beyond those directly related to the hazard found. Families with any home hazard may be candidates for interventions to childproof against other types of home hazards. PMID:16998079

Analysis on Two Typical Landslide Hazard Phenomena in The Wenchuan Earthquake by Field Investigations and Shaking Table Tests.

PubMed

Yang, Changwei; Zhang, Jianjing; Liu, Feicheng; Bi, Junwei; Jun, Zhang

2015-08-06

Based on our field investigations of landslide hazards in the Wenchuan earthquake, some findings can be reported: (1) the multi-aspect terrain facing empty isolated mountains and thin ridges reacted intensely to the earthquake and was seriously damaged; (2) the slope angles of most landslides was larger than 45°. Considering the above disaster phenomena, the reasons are analyzed based on shaking table tests of one-sided, two-sided and four-sided slopes. The analysis results show that: (1) the amplifications of the peak accelerations of four-sided slopes is stronger than that of the two-sided slopes, while that of the one-sided slope is the weakest, which can indirectly explain the phenomena that the damage is most serious; (2) the amplifications of the peak accelerations gradually increase as the slope angles increase, and there are two inflection points which are the point where the slope angle is 45° and where the slope angle is 50°, respectively, which can explain the seismic phenomenon whereby landslide hazards mainly occur on the slopes whose slope angle is bigger than 45°. The amplification along the slope strike direction is basically consistent, and the step is smooth.

Assessing Lightning and Wildfire Hazard by Land Properties and Cloud to Ground Lightning Data with Association Rule Mining in Alberta, Canada

PubMed Central

Cha, DongHwan; Wang, Xin; Kim, Jeong Woo

2017-01-01

Hotspot analysis was implemented to find regions in the province of Alberta (Canada) with high frequency Cloud to Ground (CG) lightning strikes clustered together. Generally, hotspot regions are located in the central, central east, and south central regions of the study region. About 94% of annual lightning occurred during warm months (June to August) and the daily lightning frequency was influenced by the diurnal heating cycle. The association rule mining technique was used to investigate frequent CG lightning patterns, which were verified by similarity measurement to check the patterns’ consistency. The similarity coefficient values indicated that there were high correlations throughout the entire study period. Most wildfires (about 93%) in Alberta occurred in forests, wetland forests, and wetland shrub areas. It was also found that lightning and wildfires occur in two distinct areas: frequent wildfire regions with a high frequency of lightning, and frequent wild-fire regions with a low frequency of lightning. Further, the preference index (PI) revealed locations where the wildfires occurred more frequently than in other class regions. The wildfire hazard area was estimated with the CG lightning hazard map and specific land use types. PMID:29065564

Assessing Lightning and Wildfire Hazard by Land Properties and Cloud to Ground Lightning Data with Association Rule Mining in Alberta, Canada.

PubMed

Cha, DongHwan; Wang, Xin; Kim, Jeong Woo

2017-10-23

Hotspot analysis was implemented to find regions in the province of Alberta (Canada) with high frequency Cloud to Ground (CG) lightning strikes clustered together. Generally, hotspot regions are located in the central, central east, and south central regions of the study region. About 94% of annual lightning occurred during warm months (June to August) and the daily lightning frequency was influenced by the diurnal heating cycle. The association rule mining technique was used to investigate frequent CG lightning patterns, which were verified by similarity measurement to check the patterns' consistency. The similarity coefficient values indicated that there were high correlations throughout the entire study period. Most wildfires (about 93%) in Alberta occurred in forests, wetland forests, and wetland shrub areas. It was also found that lightning and wildfires occur in two distinct areas: frequent wildfire regions with a high frequency of lightning, and frequent wild-fire regions with a low frequency of lightning. Further, the preference index (PI) revealed locations where the wildfires occurred more frequently than in other class regions. The wildfire hazard area was estimated with the CG lightning hazard map and specific land use types.

Temporal expectancy in the context of a theory of visual attention.

PubMed

Vangkilde, Signe; Petersen, Anders; Bundesen, Claus

2013-10-19

Temporal expectation is expectation with respect to the timing of an event such as the appearance of a certain stimulus. In this paper, temporal expectancy is investigated in the context of the theory of visual attention (TVA), and we begin by summarizing the foundations of this theoretical framework. Next, we present a parametric experiment exploring the effects of temporal expectation on perceptual processing speed in cued single-stimulus letter recognition with unspeeded motor responses. The length of the cue-stimulus foreperiod was exponentially distributed with one of six hazard rates varying between blocks. We hypothesized that this manipulation would result in a distinct temporal expectation in each hazard rate condition. Stimulus exposures were varied such that both the temporal threshold of conscious perception (t0 ms) and the perceptual processing speed (v letters s(-1)) could be estimated using TVA. We found that the temporal threshold t0 was unaffected by temporal expectation, but the perceptual processing speed v was a strikingly linear function of the logarithm of the hazard rate of the stimulus presentation. We argue that the effects on the v values were generated by changes in perceptual biases, suggesting that our perceptual biases are directly related to our temporal expectations.

Revision of the geological context of the Port-au-Prince metropolitan area, Haiti: implications for slope failures and seismic hazard assessment

NASA Astrophysics Data System (ADS)

Terrier, M.; Bialkowski, A.; Nachbaur, A.; Prépetit, C.; Joseph, Y. F.

2014-09-01

Following the earthquake of 12 January 2010 in the Port-au-Prince area, the Haitian government, in close cooperation with BRGM, the French geological Survey, decided to undertake a seismic microzonation study of the metropolitan area of the capital in order to take more fully into account the seismic risk in the urbanization and planning of the city under reconstruction. As the first step of the microzonation project, a geological study has been carried out. Deposits of Miocene and Pliocene formations in a marine environment have been identified. These deposits are affected by the Enriquillo-Plantain Garden N80° E fault system and N110° E faults. Tectonic observations and morphological analysis indicate Quaternary activity of several faults mapped in the area of Port-au-Prince. These faults have a N110° trend and show a reverse-sinistral strike-slip motion. Moreover, on the basis of these geological results and of new topographical data, a hazard assessment of ground movements has been made. Along with the map of active faults, the hazard map of ground movements is an integral component of the seismic microzonation study.

Required length of guardrails before hazards.

PubMed

Tomasch, E; Sinz, W; Hoschopf, H; Gobald, M; Steffan, H; Nadler, B; Nadler, F; Strnad, B; Schneider, F

2011-11-01

One way to protect against impacts during run-off-road accidents with infrastructure is the use of guardrails. However, real-world accidents indicate that vehicles can leave the road and end up behind the guardrail. These vehicles have no possibility of returning to the lane. Vehicles often end up behind the guardrail because the length of the guardrails installed before hazards is too short; this can lead to a collision with a shielded hazard. To identify the basic speed for determining the necessary length of guardrails, we analyzed the speed at which vehicles leave the roadway from the ZEDATU (Zentrale Datenbank Tödlicher Unfälle) real-world accidents database. The required length of guardrail was considered the length that reduces vehicle speed at a maximum theoretically possible deceleration of 0.3g behind the barrier based on real-world road departure speed. To determine the desired length of a guardrail ahead of a hazard, we developed a relationship between guardrail length and the speed at which vehicles depart the roadway. If the initial elements are flared away from the carriageway, the required length will be reduced by up to an additional 30% The ZEDATU database analysis showed that extending the current length of guardrails to the evaluated required length would reduce the number of fatalities among occupants of vehicles striking bridge abutments by approximately eight percent. Copyright © 2011 Elsevier Ltd. All rights reserved.

CommServer: A Communications Manager For Remote Data Sites

NASA Astrophysics Data System (ADS)

Irving, K.; Kane, D. L.

2012-12-01

CommServer is a software system that manages making connections to remote data-gathering stations, providing a simple network interface to client applications. The client requests a connection to a site by name, and the server establishes the connection, providing a bidirectional channel between the client and the target site if successful. CommServer was developed to manage networks of FreeWave serial data radios with multiple data sites, repeaters, and network-accessed base stations, and has been in continuous operational use for several years. Support for Iridium modems using RUDICS will be added soon, and no changes to the application interface are anticipated. CommServer is implemented on Linux using programs written in bash shell, Python, Perl, AWK, under a set of conventions we refer to as ThinObject.

Open Circuit Resonant Sensors for Composite Damage Detection and Diagnosis

NASA Technical Reports Server (NTRS)

Mielnik, John J., Jr.

2011-01-01

Under the Integrated Vehicle Health Management (IVHM) program work was begun to investigate the feasibility of sensor systems for detecting and diagnosing damage to aircraft composite structures and materials. Specific interest for this study was in damage initiated by environmental storm hazards and the direct effect of lightning strikes on the material structures of a composite aircraft in flight. A series of open circuit resonant sensors was designed, fabricated, characterized, and determined to be a potentially viable means for damage detection and diagnosis of composite materials. The results of this research and development effort are documented in this report.

Analysis of tectonic features in US southwest from Skylab photographs

NASA Technical Reports Server (NTRS)

Abdel-Gawad, M. (Principal Investigator); Tubbesing, L.

1975-01-01

The author has identified the following significant results. Skylab photographs were utilized to study faults and tectonic lines in selected areas of the U.S. Southwest. Emphasis was on elements of the Texas Zone in the Mojave Desert and the tectonic intersection in southern Nevada. Transverse faults believed to represent the continuation of the Texas Zone were found to be anomalous in strike. This suggests that the Mojave Desert block was rotated counterclockwise as a unit with the Sierra Nevada. Left-lateral strike-slip faults in Lake Mead area are interpreted as elements of the Wasatch tectonic zone; their anomalous trend indicates that the Lake Mead area has rotated clockwise with the Colorado Plateau. A tectonic model relating major fault zones to fragmentation and rotation of crustal blocks was developed. Detailed correlation of the high resolution S190B metric camera photographs with U-2 photographs and geologic maps demonstrates the feasibility of utilizing S190B photographs for the identification of geomorphic features associated with recent and active faults and for the assessment of seismic hazards.

Surface Rupture Effects on Earthquake Moment-Area Scaling Relations

NASA Astrophysics Data System (ADS)

Luo, Yingdi; Ampuero, Jean-Paul; Miyakoshi, Ken; Irikura, Kojiro

2017-09-01

Empirical earthquake scaling relations play a central role in fundamental studies of earthquake physics and in current practice of earthquake hazard assessment, and are being refined by advances in earthquake source analysis. A scaling relation between seismic moment ( M 0) and rupture area ( A) currently in use for ground motion prediction in Japan features a transition regime of the form M 0- A 2, between the well-recognized small (self-similar) and very large (W-model) earthquake regimes, which has counter-intuitive attributes and uncertain theoretical underpinnings. Here, we investigate the mechanical origin of this transition regime via earthquake cycle simulations, analytical dislocation models and numerical crack models on strike-slip faults. We find that, even if stress drop is assumed constant, the properties of the transition regime are controlled by surface rupture effects, comprising an effective rupture elongation along-dip due to a mirror effect and systematic changes of the shape factor relating slip to stress drop. Based on this physical insight, we propose a simplified formula to account for these effects in M 0- A scaling relations for strike-slip earthquakes.

Preliminary volcano-hazard assessment for Akutan Volcano east-central Aleutian Islands, Alaska

USGS Publications Warehouse

Waythomas, Christopher F.; Power, John A.; Richter, Donlad H.; McGimsey, Robert G.

1998-01-01

Akutan Volcano is a 1100-meter-high stratovolcano on Akutan Island in the east-central Aleutian Islands of southwestern Alaska. The volcano is located about 1238 kilometers southwest of Anchorage and about 56 kilometers east of Dutch Harbor/Unalaska. Eruptive activity has occurred at least 27 times since historical observations were recorded beginning in the late 1700?s. Recent eruptions produced only small amounts of fine volcanic ash that fell primarily on the upper flanks of the volcano. Small amounts of ash fell on the Akutan Harbor area during eruptions in 1911, 1948, 1987, and 1989. Plumes of volcanic ash are the primary hazard associated with eruptions of Akutan Volcano and are a major hazard to all aircraft using the airfield at Dutch Harbor or approaching Akutan Island. Eruptions similar to historical Akutan eruptions should be anticipated in the future. Although unlikely, eruptions larger than those of historical time could generate significant amounts of volcanic ash, fallout, pyroclastic flows, and lahars that would be hazardous to life and property on all sectors of the volcano and other parts of the island, but especially in the major valleys that head on the volcano flanks. During a large eruption an ash cloud could be produced that may be hazardous to aircraft using the airfield at Cold Bay and the airspace downwind from the volcano. In the event of a large eruption, volcanic ash fallout could be relatively thick over parts of Akutan Island and volcanic bombs could strike areas more than 10 kilometers from the volcano.

The Wallula fault and tectonic framework of south-central Washington, as interpreted from magnetic and gravity anomalies

USGS Publications Warehouse

Blakely, Richard J.; Sherrod, Brian; Weaver, Craig S.; Wells, Ray; Rohay, Alan C.

2014-01-01

The Yakima fold and thrust belt (YFTB) in central Washington has accommodated regional, mostly north-directed, deformation of the Cascadia backarc since prior to emplacement of Miocene flood basalt of the Columbia River Basalt Group (CRBG). The YFTB consists of two structural domains. Northern folds of the YFTB strike eastward and terminate at the western margin of a 20-mGal negative gravity anomaly, the Pasco gravity low, straddling the North American continental margin. Southern folds of the YFTB strike southeastward, form part of the Olympic–Wallowa lineament (OWL), and pass south of the Pasco gravity low as the Wallula fault zone. An upper crustal model based on gravity and magnetic anomalies suggests that the Pasco gravity low is caused in part by an 8-km-deep Tertiary basin, the Pasco sub-basin, abutting the continental margin and concealed beneath CRBG. The Pasco sub-basin is crossed by north-northwest-striking magnetic anomalies caused by dikes of the 8.5 Ma Ice Harbor Member of the CRBG. At their northern end, dikes connect with the eastern terminus of the Saddle Mountains thrust of the YFTB. At their southern end, dikes are disrupted by the Wallula fault zone. The episode of NE–SW extension that promoted Ice Harbor dike injection apparently involved strike-slip displacement on the Saddle Mountains and Wallula faults. The amount of lateral shear on the OWL impacts the level of seismic hazard in the Cascadia region. Ice Harbor dikes, as mapped with aeromagnetic data, are dextrally offset by the Wallula fault zone a total of 6.9 km. Assuming that dike offsets are tectonic in origin, the Wallula fault zone has experienced an average dextral shear of 0.8 mm/y since dike emplacement 8.5 Ma, consistent with right-lateral stream offsets observed at other locations along the OWL. Southeastward, the Wallula fault transfers strain to the north-striking Hite fault, the possible location of the M 5.7 Milton-Freewater earthquake in 1936.

Predicting Impacts of Lightning Strikes on Aviation under a Changing Climate Using Regression Kriging

NASA Astrophysics Data System (ADS)

Rakas, J.; Ding, C.; Murthi, A.; Lukovic, J.; Bajat, B.

2016-12-01

Lightning is a serious hazard that can cause significant impacts on human infrastructure. In the aviation industry, lightning strikes cause damage and outages to air traffic control equipment and facilities at airports that result in major disruptions in commercial air travel, compounding delays during storm events that lead to losses in the millions of dollars. To date poor attention has been given to how lightning might change with the increase of greenhouse gases and temperature. Under some climate change scenarios, the increase in the occurrence and severity of storms in the future with potential for increases in lightning activity has been studied. Recent findings suggest that lighting rates will increase 12 percent per every degree Celsius rise in global temperatures. That will results to a 50 percent increase by the end of the century. Accurate prediction of the intensity and frequency of lightning strikes is therefore required by the air traffic management and control sector in order to develop more robust adaptation and mitigation strategies under the threat of global climate change and increasing lightning rates. In this work, we use the regression kriging method to predict lightning strikes over several regions over the contiguous United Sates using two meteorological variables- namely convective available potential energy (CAPE) and total precipitation rate. These two variables are used as a measure of storm convection, since strong convections are related to more lightning. Specifically, CAPE multiplied by precipitation is used as a proxy for lightning strikes owing to a strong linear relationship between the two. These two meteorological variables are obtained from a subset of models used in phase 5 of the coupled model inter-comparison experiment pertaining to the "high emissions" climate change scenario corresponding to the representative concentration pathway (RCP) 8.5. Precipitation observations from the National Weather Cooperative Network (COOP) were incorporated as an additional dataset. This scenario indicates a doubling of CAPE and precipitation resulting in significant increases in CAPE×precipitation by the end of the century. Overall, this research highlights the use of global climate models and observations to assess climate change impacts on aviation.

The Mw6.5 17 November 2015 Lefkada (Greece) Earthquake: Structural Interpretation by Means of the Aftershock Analysis

NASA Astrophysics Data System (ADS)

Papadimitriou, E.; Karakostas, V.; Mesimeri, M.; Chouliaras, G.; Kourouklas, Ch.

2017-10-01

The 2015 Mw6.5 Lefkada main shock occurred at the south western part of Lefkada Island (Greece), less than 2 years after the occurrence of a doublet along the western part of the nearby Kefalonia Island, Paliki peninsula (on 25/01/2014, with Mw6.1 and 03/02/2014 with Mw6.0) and 12 years after the 2003 Mw6.2 main shock that struck the northwestern part of Lefkada Island. The four failed dextral strike slip fault segments belong to the Kefalonia transform fault zone (KTFZ), the major active boundary that bounds from the west the area of central Ionian Islands, namely Lefkada and Kefalonia. It is associated with several known historical earthquakes and is considered the most hazardous area in the Greek territory. The KTFZ fault segments are characterized by high slip rates (of the order of tens of millimeters per year), with maximum earthquake magnitudes up to 6.7 for Lefkada and 7.2 for Kefalonia fault zone, respectively. The double difference location technique was employed for relocating the aftershocks revealing a seismogenic layer extending from 3 to 16 km depth and multiple activation on well-defined fault planes, with strikes that differ than the main rupture and dips either to east or to west. This implies that strain energy was not solely released on a main fault only, but on secondary and adjacent fault segments as well. The reliable definition of their geometry forms the basis for the structural interpretation of the local fault network. The aftershock spatial distribution indicates three main clusters of the seismic activity, along with activation of smaller faults to an extent of more than 50 km. A northeasterly striking cluster is observed to the north of the main shock epicenter, with a remarkable aftershock density. The central cluster is less dense than the previous one with an epicentral alignment in full accordance with the strike provided by the main shock centroid moment tensor solution, and is considered as the main rupture with a length of 17 km. The third cluster, encompassing a large number of aftershocks, is located in the offshore area between Lefkada and Kefalonia Islands with a NE-SW epicentral alignment, alike the first cluster. The northeast-southwest striking secondary faults positioned obliquely and in continuation of the main fault segment, reveal that the KTFZ is being deformed in a complex tectonic setting. The presence of faults with this geometry implies strain partitioning and sheds light to new components necessary to be taken into account in the seismic hazard assessment. Stress transfer models of the M ≥6.0 main shocks were investigated and the calculated static stress changes may well explain their sequential occurrence. Static stress changes due to the 2015 coseismic slip were also calculated with the main objective of exploring the aftershock occurrence pattern and it was found as the driving mechanism that triggered the vast majority of the off-fault aftershocks.

Probabilistic seismic hazard assessment for northern Southeast Asia

NASA Astrophysics Data System (ADS)

Chan, C. H.; Wang, Y.; Kosuwan, S.; Nguyen, M. L.; Shi, X.; Sieh, K.

2016-12-01

We assess seismic hazard for northern Southeast Asia through constructing an earthquake and fault database, conducting a series of ground-shaking scenarios and proposing regional seismic hazard maps. Our earthquake database contains earthquake parameters from global and local seismic catalogues, including the ISC, ISC-GEM, the global ANSS Comprehensive Catalogues, Seismological Bureau, Thai Meteorological Department, Thailand, and Institute of Geophysics Vietnam Academy of Science and Technology, Vietnam. To harmonize the earthquake parameters from various catalogue sources, we remove duplicate events and unify magnitudes into the same scale. Our active fault database include active fault data from previous studies, e.g. the active fault parameters determined by Wang et al. (2014), Department of Mineral Resources, Thailand, and Institute of Geophysics, Vietnam Academy of Science and Technology, Vietnam. Based on the parameters from analysis of the databases (i.e., the Gutenberg-Richter relationship, slip rate, maximum magnitude and time elapsed of last events), we determined the earthquake recurrence models of seismogenic sources. To evaluate the ground shaking behaviours in different tectonic regimes, we conducted a series of tests by matching the felt intensities of historical earthquakes to the modelled ground motions using ground motion prediction equations (GMPEs). By incorporating the best-fitting GMPEs and site conditions, we utilized site effect and assessed probabilistic seismic hazard. The highest seismic hazard is in the region close to the Sagaing Fault, which cuts through some major cities in central Myanmar. The northern segment of Sunda megathrust, which could potentially cause M8-class earthquake, brings significant hazard along the Western Coast of Myanmar and eastern Bangladesh. Besides, we conclude a notable hazard level in northern Vietnam and the boundary between Myanmar, Thailand and Laos, due to a series of strike-slip faults, which could potentially cause moderate-large earthquakes. Note that although much of the region has a low probability of damaging shaking, low-probability events have resulted in much destruction recently in SE Asia (e.g. 2008 Wenchuan, 2015 Sabah earthquakes).

3D Dynamic Rupture Simulations along Dipping Faults, with a focus on the Wasatch Fault Zone, Utah

NASA Astrophysics Data System (ADS)

Withers, K.; Moschetti, M. P.

2017-12-01

We study dynamic rupture and ground motion from dip-slip faults in regions that have high-seismic hazard, such as the Wasatch fault zone, Utah. Previous numerical simulations have modeled deterministic ground motion along segments of this fault in the heavily populated regions near Salt Lake City but were restricted to low frequencies ( 1 Hz). We seek to better understand the rupture process and assess broadband ground motions and variability from the Wasatch Fault Zone by extending deterministic ground motion prediction to higher frequencies (up to 5 Hz). We perform simulations along a dipping normal fault (40 x 20 km along strike and width, respectively) with characteristics derived from geologic observations to generate a suite of ruptures > Mw 6.5. This approach utilizes dynamic simulations (fully physics-based models, where the initial stress drop and friction law are imposed) using a summation by parts (SBP) method. The simulations include rough-fault topography following a self-similar fractal distribution (over length scales from 100 m to the size of the fault) in addition to off-fault plasticity. Energy losses from heat and other mechanisms, modeled as anelastic attenuation, are also included, as well as free-surface topography, which can significantly affect ground motion patterns. We compare the effect of material structure and both rate and state and slip-weakening friction laws have on rupture propagation. The simulations show reduced slip and moment release in the near surface with the inclusion of plasticity, better agreeing with observations of shallow slip deficit. Long-wavelength fault geometry imparts a non-uniform stress distribution along both dip and strike, influencing the preferred rupture direction and hypocenter location, potentially important for seismic hazard estimation.

Static stress changes associated with normal faulting earthquakes in South Balkan area

NASA Astrophysics Data System (ADS)

Papadimitriou, E.; Karakostas, V.; Tranos, M.; Ranguelov, B.; Gospodinov, D.

2007-10-01

Activation of major faults in Bulgaria and northern Greece presents significant seismic hazard because of their proximity to populated centers. The long recurrence intervals, of the order of several hundred years as suggested by previous investigations, imply that the twentieth century activation along the southern boundary of the sub-Balkan graben system, is probably associated with stress transfer among neighbouring faults or fault segments. Fault interaction is investigated through elastic stress transfer among strong main shocks ( M ≥ 6.0), and in three cases their foreshocks, which ruptured distinct or adjacent normal fault segments. We compute stress perturbations caused by earthquake dislocations in a homogeneous half-space. The stress change calculations were performed for faults of strike, dip, and rake appropriate to the strong events. We explore the interaction between normal faults in the study area by resolving changes of Coulomb failure function ( ΔCFF) since 1904 and hence the evolution of the stress field in the area during the last 100 years. Coulomb stress changes were calculated assuming that earthquakes can be modeled as static dislocations in an elastic half-space, and taking into account both the coseismic slip in strong earthquakes and the slow tectonic stress buildup associated with major fault segments. We evaluate if these stress changes brought a given strong earthquake closer to, or sent it farther from, failure. Our modeling results show that the generation of each strong event enhanced the Coulomb stress on along-strike neighbors and reduced the stress on parallel normal faults. We extend the stress calculations up to present and provide an assessment for future seismic hazard by identifying possible sites of impending strong earthquakes.

Active tectonics of the Imperial Valley, southern California: fault damage zones, complex basins and buried faults

NASA Astrophysics Data System (ADS)

Persaud, P.; Ma, Y.; Stock, J. M.; Hole, J. A.; Fuis, G. S.; Han, L.

2016-12-01

Ongoing oblique slip at the Pacific-North America plate boundary in the Salton Trough produced the Imperial Valley. Deformation in this seismically active area is distributed across a complex network of exposed and buried faults resulting in a largely unmapped seismic hazard beneath the growing population centers of El Centro, Calexico and Mexicali. To better understand the shallow crustal structure in this region and the connectivity of faults and seismicity lineaments, we used data primarily from the Salton Seismic Imaging Project (SSIP) to construct a P-wave velocity profile to 15 km depth, and a 3-D velocity model down to 8 km depth including the Brawley Geothermal area. We obtained detailed images of a complex wedge-shaped basin at the southern end of the San Andreas Fault system. Two deep subbasins (VP <5.65 km/s) are located in the western part of the larger Imperial Valley basin, where seismicity trends and active faults play a significant role in shaping the basin edge. Our 3-D VP model reveals previously unrecognized NE-striking cross faults that are interacting with the dominant NW-striking faults to control deformation. New findings in our profile include localized regions of low VP (thickening of a 5.65-5.85 km/s layer) near faults or seismicity lineaments interpreted as possibly faulting-related. Our 3-D model and basement map reveal velocity highs associated with the geothermal areas in the eastern valley. The improved seismic velocity model from this study, and the identification of important unmapped faults or buried interfaces will help refine the seismic hazard for parts of Imperial County, California.

Fractographic logging for determination of pre-core and core-induced fractures: Nicholas Combs No. 7239 well, Hazard, Kentucky

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulander, B.R.; Dean, S.L.; Barton, C.C.

1977-01-01

Methods results, and conclusions formulated during a prototype fractographic logging study of seventy-five feet of oriented Devonian shale core are summarized. The core analyzed is from the Nicholas Combs No. 7239 well located twelve miles due north of Hazard, Kentucky. The seventy-five foot core length was taken from a cored section lying between 2369.0 feet (subsea) and 2708.0 feet (subsea). Total core length is 339.0 feet. The core was extracted from the upper Devonian Ohio and Olentangy shale formations. Results indicate that there are few tectonic (pre-core) fractures within the studied core section. The region may nevertheless be cut atmore » core sample depth by well-defined vertical or inclined tectonic fractures that the vertically drilled test core didn't intersect. This is likely since surface Plateau systematic fractures in other Plateau areas are vertical to sub-vertical and seldom have a frequency of less than one major fracture per foot. The remarkable directional preference of set three fractures about strikes of N 40/sup 0/ E, N 10/sup 0/ W, N 45/sup 0/ W, suggests some incipient pre-core rock anisotropy or stored directional strain energy. If this situation exists, the anisotropy strike change or stored strain variance from N 40/sup 0/ E to N 45/sup 0/ W downcore remains an unanswered question. Tectonic features, indicating local and/or regional movement plans, are present on and within the tectonichorizontal fracture set one. Slickensides had a preferred orientation within several core levels, and fibrous-nonfibrous calcite serves as fracture fillings.« less

Escape tectonics in the Los Angeles metropolitan region and implications for seismic risk

NASA Astrophysics Data System (ADS)

Walls, Christian; Rockwell, Thomas; Mueller, Karl; Bock, Yehuda; Williams, Simon; Pfanner, John; Dolan, James; Fang, Peng

1998-07-01

Recent damaging earthquakes in California, including the 1971 San Fernando, 1983 Coalinga, 1987 Whittier Narrows and 1994 Northridge events, have drawn attention to thrust faults as both potentially hazardous seismic sources and as a mechanism for accommodating shortening in many regions of southern California. Consequently, many geological studies, have concluded that thrust faults in Southern California pose the greatest seismic hazard, and also account for most of the estimated 5-7mmyr-1 of contraction across the greater Los Angeles metropolitan area, indicated by Global Positioning System geodetic measurements. Our study demonstrates, however, that less than 50% of the geodetically observed contraction is accommodated on the principal thrust systems across the Los Angeles region. We integrate the most recent geological, geodetic and seismological data to assess the spatial distribution of strain across the Los Angeles metropolitan region. We then demonstrate that a significant component of seismic moment release and shortening in this region is accommodated by east-west crustal escape `extrusion' along known strike-slip and oblique-slip faults.

[Decontamination of chemical warfare agents by photocatalysis].

PubMed

Hirakawa, Tsutomu; Mera, Nobuaki; Sano, Taizo; Negishi, Nobuaki; Takeuchi, Koji

2009-01-01

Photocatalysis has been widely applied to solar-energy conversion and environmental purification. Photocatalyst, typically titanium dioxide (TiO(2)), produces active oxygen species under irradiation of ultraviolet light, and can decompose not only conventional pollutants but also different types of hazardous substances at mild conditions. We have recently started the study of photocatalytic decontamination of chemical warfare agents (CWAs) under collaboration with the National Research Institute of Police Science. This article reviews environmental applications of semiconductor photocatalysis, decontamination methods for CWAs, and previous photocatalytic studies applied to CWA degradation, together with some of our results obtained with CWAs and their simulant compounds. The data indicate that photocatalysis, which may not always give a striking power, certainly helps detoxification of such hazardous compounds. Unfortunately, there are not enough data obtained with real CWAs due to the difficulty in handling. We will add more scientific data using CWAs in the near future to develop useful decontamination systems that can reduce the damage caused by possible terrorism.

Potential for larger earthquakes in the East San Francisco Bay Area due to the direct connection between the Hayward and Calaveras Faults

NASA Astrophysics Data System (ADS)

Chaussard, E.; Bürgmann, R.; Fattahi, H.; Nadeau, R. M.; Taira, T.; Johnson, C. W.; Johanson, I.

2015-04-01

The Hayward and Calaveras Faults, two strike-slip faults of the San Andreas System located in the East San Francisco Bay Area, are commonly considered independent structures for seismic hazard assessment. We use Interferometric Synthetic Aperture RADAR to show that surface creep on the Hayward Fault continues 15 km farther south than previously known, revealing new potential for rupture and damage south of Fremont. The extended trace of the Hayward Fault, also illuminated by shallow repeating micro-earthquakes, documents a surface connection with the Calaveras Fault. At depths greater than 3-5 km, repeating micro-earthquakes located 10 km north of the surface connection highlight the 3-D wedge geometry of the junction. Our new model of the Hayward and Calaveras Faults argues that they should be treated as a single system with potential for earthquake ruptures generating events with magnitudes greater than 7, posing a higher seismic hazard to the East San Francisco Bay Area than previously considered.

Bashing Pseudoscience in Academia

NASA Astrophysics Data System (ADS)

Hameed, S.; Robinson, G. M.; Moulton, J.

2003-12-01

Belief in paranormal, supernatural and other new-age claims is increasing according to surveys by the NSF and others. Astronomy-related pseudo-scientific beliefs are especially common. For example, more than thirty percent of Americans consider astrology to be scientific and more than one-third believe that extraterrestrial beings have visited earth at some time in the past. Not only do such beliefs ignore sound reasoning and information but they compete as alternative explanations for the world around us. While a general education might be expected to reduce acceptance of unsound beliefs, the level of such belief is surprisingly high among those with a higher education. An astronomer, a philosopher and a psychologist cooperated in developing a brief college course designed to challenge unsound reasoning and information, and to inoculate the participants with skepticism. Pre- and post-course opinion surveys show significant changes in belief.

Mario Bunge's Materialist Theory of Mind and Contemporary Cognitive Science

NASA Astrophysics Data System (ADS)

Slezak, Peter

2012-10-01

Bunge's writings on the mind-body problem provide a rigorous, analytical antidote to the persistent anti-materialist tendency that has characterized the history of philosophy and science. Bunge gives special attention to dualism and its shortcomings, and this attention is welcome in view of the resurgence of the doctrine today. However, I focus my comments selectively on Bunge's more controversial, provocative claims, not to dismiss them, but to engage with them seriously. For example, a difficulty arising from Bunge's rhetorical style and its undoubted virtues is that not all the targets of his selfconfessed "bashings" (2010, xi) are equally deserving. For example, Bunge suggests "most contemporary philosophers of mind are indifferent to psychology, or are remarkably uninformed about it". This charge cannot be sustained today in light of the work of foremost philosophers today.

What's really behind the attack on silicone breast implants.

PubMed

Angell, M

1996-09-09

Millions of dollars are being awarded by injuries and a major company has been forced into bankruptcy because of litigation over silicone breast implants. Yet scientific research hasn't established a link between the implants and disease, notes Marcia Angell, executive editor of the New England Journal of Medicine. When she began studying the issue, this self-described feminist and liberal Democrat expected to uncover iniquities of big business and the implant manufacturers. Instead, she's written an indictment of the tort system, junk science, and the gullibility of the news media. Attorneys have twisted facts and played on the emotions of juries, with the consent of judges and often to the cheers of the press. Angell worries that it's now become politically correct to bash the scientific method in the name of diversity, multiculturalism, and feminism.

Shallow seismic reflection profiles and geological structure in the Benton Hills, southeast Missouri

USGS Publications Warehouse

Palmer, J.R.; Hoffman, D.; Stephenson, W.J.; Odum, J.K.; Williams, R.A.

1997-01-01

During late May and early June of 1993, we conducted two shallow, high-resolution seismic reflection surveys (Mini-Sosie method) across the southern escarpment of the Benton Hills segment of Crowleys Ridge. The reflection profiles imaged numerous post-late Cretaceous faults and folds. We believe these faults may represent a significant earthquake source zone. The stratigraphy of the Benton Hills consists of a thin, less than about 130 m, sequence of mostly unconsolidated Cretaceous, Tertiary and Quaternary sediments which unconformably overlie a much thicker section of Paleozoic carbonate rocks. The survey did not resolve reflectors within the upper 75-100 ms of two-way travel time (about 60-100 m), which would include all of the Tertiary and Quaternary and most of the Cretaceous. However, the Paleozoic-Cretaceous unconformity (Pz) produced an excellent reflection, and, locally a shallower reflector within the Cretaceous (K) was resolved. No coherent reflections below about 200 ms of two-way travel time were identified. Numerous faults and folds, which clearly offset the Paleozoic-Cretaceous unconformity reflector, were imaged on both seismic reflection profiles. Many structures imaged by the reflection data are coincident with the surface mapped locations of faults within the Cretaceous and Tertiary succession. Two locations show important structures that are clearly complex fault zones. The English Hill fault zone, striking N30??-35??E, is present along Line 1 and is important because earlier workers indicated it has Pleistocene Loess faulted against Eocene sands. The Commerce fault zone striking N50??E, overlies a major regional basement geophysical lineament, and is present on both seismic lines at the southern margin of the escarpment. The fault zones imaged by these surveys are 30 km from the area of intense microseismicity in the New Madrid seismic zone (NMSZ). If these are northeast and north-northeast oriented fault zones like those at Thebes Gap they are favorably oriented in the modern stress field to be reactivated as right-lateral strike slip faults. Currently, earthquake hazards assessments are most dependent upon historical seismicity, and there are little geological data available to evaluate the earthquake potential of fault zones outside of the NMSZ. We anticipate that future studies will provide evidence that seismicity has migrated between fault zones well beyond the middle Mississippi Valley. The potential earthquake hazards represented by faults outside the NMSZ may be significant.

Volcanic hazard communication using maps: an evaluation of their effectiveness

NASA Astrophysics Data System (ADS)

Haynes, Katharine; Barclay, Jenni; Pidgeon, Nick

2007-11-01

Hazard maps are considered essential tools in the communication of volcanic risk between scientists, the local authorities and the public. This study investigates the efficacy of such maps for the volcanic island of Montserrat in the West Indies using both quantitative and qualitative research techniques. Normal plan view maps, which have been used on the island over the last 10 years of the crisis, are evaluated against specially produced three-dimensional (3D) maps and perspective photographs. Thirty-two demographically representative respondents of mixed backgrounds, sex, education and location were interviewed and asked to complete a range of tasks and identification on the maps and photographs. The overall results show that ordinary people have problems interpreting their environment as a mapped representation. We found respondents’ ability to locate and orientate themselves as well as convey information relating to volcanic hazards was improved when using aerial photographs rather than traditional plan view contour maps. There was a slight improvement in the use of the 3D maps, especially in terms of topographic recognition. However, the most striking increase in effectiveness was found with the perspective photographs, which enabled people to identify features and their orientation much more readily. For Montserrat it appears that well labelled aerial and perspective photographs are the most effective geo-spatial method of communicating volcanic risks.

Analysis on Two Typical Landslide Hazard Phenomena in The Wenchuan Earthquake by Field Investigations and Shaking Table Tests

PubMed Central

Yang, Changwei; Zhang, Jianjing; Liu, Feicheng; Bi, Junwei; Jun, Zhang

2015-01-01

Based on our field investigations of landslide hazards in the Wenchuan earthquake, some findings can be reported: (1) the multi-aspect terrain facing empty isolated mountains and thin ridges reacted intensely to the earthquake and was seriously damaged; (2) the slope angles of most landslides was larger than 45°. Considering the above disaster phenomena, the reasons are analyzed based on shaking table tests of one-sided, two-sided and four-sided slopes. The analysis results show that: (1) the amplifications of the peak accelerations of four-sided slopes is stronger than that of the two-sided slopes, while that of the one-sided slope is the weakest, which can indirectly explain the phenomena that the damage is most serious; (2) the amplifications of the peak accelerations gradually increase as the slope angles increase, and there are two inflection points which are the point where the slope angle is 45° and where the slope angle is 50°, respectively, which can explain the seismic phenomenon whereby landslide hazards mainly occur on the slopes whose slope angle is bigger than 45°. The amplification along the slope strike direction is basically consistent, and the step is smooth. PMID:26258785

Temporal expectancy in the context of a theory of visual attention

PubMed Central

Vangkilde, Signe; Petersen, Anders; Bundesen, Claus

2013-01-01

Temporal expectation is expectation with respect to the timing of an event such as the appearance of a certain stimulus. In this paper, temporal expectancy is investigated in the context of the theory of visual attention (TVA), and we begin by summarizing the foundations of this theoretical framework. Next, we present a parametric experiment exploring the effects of temporal expectation on perceptual processing speed in cued single-stimulus letter recognition with unspeeded motor responses. The length of the cue–stimulus foreperiod was exponentially distributed with one of six hazard rates varying between blocks. We hypothesized that this manipulation would result in a distinct temporal expectation in each hazard rate condition. Stimulus exposures were varied such that both the temporal threshold of conscious perception (t0 ms) and the perceptual processing speed (v letters s−1) could be estimated using TVA. We found that the temporal threshold t0 was unaffected by temporal expectation, but the perceptual processing speed v was a strikingly linear function of the logarithm of the hazard rate of the stimulus presentation. We argue that the effects on the v values were generated by changes in perceptual biases, suggesting that our perceptual biases are directly related to our temporal expectations. PMID:24018716

Enriquillo–Plantain Garden fault zone in Jamaica: paleoseismology and seismic hazard

USGS Publications Warehouse

Koehler, R.D.; Mann, P.; Prentice, Carol S.; Brown, L.; Benford, B.; Grandison-Wiggins, M.

2013-01-01

The countries of Jamaica, Haiti, and the Dominican Republic all straddle the Enriquillo–Plantain Garden fault zone ( EPGFZ), a major left-lateral, strike-slip fault system bounding the Caribbean and North American plates. Past large earthquakes that destroyed the capital cities of Kingston, Jamaica (1692, 1907), and Port-au-Prince, Haiti (1751, 1770), as well as the 2010 Haiti earthquake that killed more than 50,000 people, have heightened awareness of seismic hazards in the northern Caribbean. We present here new geomorphic and paleoseismic information bearing on the location and relative activity of the EPGFZ, which marks the plate boundary in Jamaica. Documentation of a river bank exposure and several trenches indicate that this fault is active and has the potential to cause major destructive earthquakes in Jamaica. The results suggest that the fault has not ruptured the surface in at least 500 yr and possibly as long as 28 ka. The long period of quiescence and subdued geomorphic expression of the EPGFZ indicates that it may only accommodate part of the ∼7–9 mm=yr plate deformation rate measured geodetically and that slip may be partitioned on other undocumented faults. Large uncertainties related to the neotectonic framework of Jamaica remain and more detailed fault characterization studies are necessary to accurately assess seismic hazards.

The offshore Palos Verdes fault zone near San Pedro, Southern California

USGS Publications Warehouse

Fisher, M.A.; Normark, W.R.; Langenheim, V.E.; Calvert, A.J.; Sliter, R.

2004-01-01

High-resolution seismic-reflection data are combined with a variety of other geophysical and geological data to interpret the offshore structure and earthquake hazards of the San Pedro shelf, near Los Angeles, California. Prominent structures investigated include the Wilmington graben, the Palos Verdes fault zone, various faults below the west part of the San Pedro shelf and slope, and the deep-water San Pedro basin. The structure of the Palos Verdes fault zone changes markedly along strike southeastward across the San Pedro shelf and slope. Under the north part of the shelf, this fault zone includes several strands, with the main strand dipping west. Under the slope, the main fault strands exhibit normal separation and mostly dip east. To the southeast near Lasuen Knoll, the Palos Verdes fault zone locally is low angle, but elsewhere near this knoll, the fault dips steeply. Fresh seafloor scarps near Lasuen Knoll indicate recent fault movement. We explain the observed structural variation along the Palos Verdes fault zone as the result of changes in strike and fault geometry along a master right-lateral strike-slip fault at depth. Complicated movement along this deep fault zone is suggested by the possible wave-cut terraces on Lasuen Knoll, which indicate subaerial exposure during the last sea level lowstand and subsequent subsidence of the knoll. Modeling of aeromagnetic data indicates a large magnetic body under the west part of the San Pedro shelf and upper slope. We interpret this body to be thick basalt of probable Miocene age. This basalt mass appears to have affected the pattern of rock deformation, perhaps because the basalt was more competent during deformation than the sedimentary rocks that encased the basalt. West of the Palos Verdes fault zone, other northwest-striking faults deform the outer shelf and slope. Evidence for recent movement along these faults is equivocal, because we lack age dates on deformed or offset sediment.

Calculating and Mitigating the Risk of a Cut Glove to a Space Walking Astronaut

NASA Technical Reports Server (NTRS)

Castillo, Theresa; Haught, Megan

2013-01-01

One of the high risk operations on the International Space Station (ISS) is conducting a space walk, or an Extra Vehicular Activity (EVA). Threats to the space walking crew include airlock failures, space suit failures, and strikes from micro ]meteoroids and orbital debris (MM/OD). There are risks of becoming untethered from the space station, being pinched between the robotic arm and a piece of equipment, tearing your suit on a sharp edge, and other human errors that can be catastrophic. For decades NASA identified and tried to control sharp edges on external structure and equipment by design; however a new and unexpected source of sharp edges has since become apparent. Until recently, one of the underappreciated environmental risks was damage to EVA gloves during a spacewalk. The ISS has some elements which have been flying in the environment of space for over 14 years. It has and continues to be bombarded with MM/OD strikes that have created small, sharp craters all over the structure, including the dedicated EVA handrails and surrounding structure. These craters are capable of cutting through several layers of the EVA gloves. Starting in 2006, five EVA crewmembers reported cuts in their gloves so large they rendered the gloves unusable and in some cases cut the spacewalk short for the safety of the crew. This new hazard took engineers and managers by surprise. NASA has set out to mitigate this risk to safety and operations by redesigning the spacesuit gloves to be more resilient and designing a clamp to isolate MM/OD strikes on handrails, and is considering the necessity of an additional tool to repair strikes on non ]handrail surfaces (such as a file). This paper will address how the ISS Risk Team quantified an estimate of the MM/OD damage to the ISS, and the resulting likelihood of sustaining a cut glove in order to measure the effectiveness of the solutions being investigated to mitigate this risk to the mission and crew.

Fish Passage though Hydropower Turbines: Simulating Blade Strike using the Discrete Element Method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richmond, Marshall C.; Romero Gomez, Pedro DJ

mong the hazardous hydraulic conditions affecting anadromous and resident fish during their passage though turbine flows, two are believed to cause considerable injury and mortality: collision on moving blades and decompression. Several methods are currently available to evaluate these stressors in installed turbines, i.e. using live fish or autonomous sensor devices, and in reduced-scale physical models, i.e. registering collisions from plastic beads. However, a priori estimates with computational modeling approaches applied early in the process of turbine design can facilitate the development of fish-friendly turbines. In the present study, we evaluated the frequency of blade strike and nadir pressure environmentmore » by modeling potential fish trajectories with the Discrete Element Method (DEM) applied to fish-like composite particles. In the DEM approach, particles are subjected to realistic hydraulic conditions simulated with computational fluid dynamics (CFD), and particle-structure interactions—representing fish collisions with turbine blades—are explicitly recorded and accounted for in the calculation of particle trajectories. We conducted transient CFD simulations by setting the runner in motion and allowing for better turbulence resolution, a modeling improvement over the conventional practice of simulating the system in steady state which was also done here. While both schemes yielded comparable bulk hydraulic performance, transient conditions exhibited a visual improvement in describing flow variability. We released streamtraces (steady flow solution) and DEM particles (transient solution) at the same location from where sensor fish (SF) have been released in field studies of the modeled turbine unit. The streamtrace-based results showed a better agreement with SF data than the DEM-based nadir pressures did because the former accounted for the turbulent dispersion at the intake but the latter did not. However, the DEM-based strike frequency is more representative of blade-strike probability than the steady solution is, mainly because DEM particles accounted for the full fish length, thus resolving (instead of modeling) the collision event.« less

The California Hazards Institute

NASA Astrophysics Data System (ADS)

Rundle, J. B.; Kellogg, L. H.; Turcotte, D. L.

2006-12-01

California's abundant resources are linked with its natural hazards. Earthquakes, landslides, wildfires, floods, tsunamis, volcanic eruptions, severe storms, fires, and droughts afflict the state regularly. These events have the potential to become great disasters, like the San Francisco earthquake and fire of 1906, that overwhelm the capacity of society to respond. At such times, the fabric of civic life is frayed, political leadership is tested, economic losses can dwarf available resources, and full recovery can take decades. A patchwork of Federal, state and local programs are in place to address individual hazards, but California lacks effective coordination to forecast, prevent, prepare for, mitigate, respond to, and recover from, the harmful effects of natural disasters. Moreover, we do not know enough about the frequency, size, time, or locations where they may strike, nor about how the natural environment and man-made structures would respond. As California's population grows and becomes more interdependent, even moderate events have the potential to trigger catastrophes. Natural hazards need not become natural disasters if they are addressed proactively and effectively, rather than reactively. The University of California, with 10 campuses distributed across the state, has world-class faculty and students engaged in research and education in all fields of direct relevance to hazards. For that reason, the UC can become a world leader in anticipating and managing natural hazards in order to prevent loss of life and property and degradation of environmental quality. The University of California, Office of the President, has therefore established a new system-wide Multicampus Research Project, the California Hazards Institute (CHI), as a mechanism to research innovative, effective solutions for California. The CHI will build on the rich intellectual capital and expertise of the Golden State to provide the best available science, knowledge and tools for leaders, managers, stakeholders, policy makers, educators and the public to effectively and comprehensively combat the problems caused by the natural hazards that threaten California. During this first year of operation, UC faculty involved in the CHI will identify the science and technology research priorities of the Institute, followed by the solicitation of participation by other important stakeholders within California. The CHI is founded upon the idea that the hazards associated with events such as earthquakes and floods need not become great disasters such as the San Francisco earthquake of 1906 and 2005 Hurricane Katrina if these hazards can be anticipated proactively, before they must be dealt with reactively.

Improved method for roadside barrier length of need modeling using real-world trajectories.

PubMed

Johnson, Nicholas S; Thomson, Robert; Gabler, Hampton C

2015-07-01

The 2011 AASHTO Roadside Design Guide (RDG) contains perhaps the most widely used procedure for choosing an appropriate length of need (LON) for roadside barriers. However, this procedure has several limitations. The procedure uses a highly simplified model of vehicle departure, and the procedure does not allow designers to specify an explicit level of protection. A new procedure for choosing LON that addresses these limitations is presented in this paper. This new procedure is based on recent, real-world road departure trajectories and uses this departure data in a more realistic way. The new procedure also allows LON to be specified for a precisely known level of protection - a level which can be based on number of crashes, injury outcomes or even estimated crash cost - while still remaining straightforward and quick to use like the 2011 RDG procedure. In this analysis, the improved procedure was used to explore the effects of the RDG procedure's assumptions. LON recommendations given by the 2011 RDG procedure were compared with recommendations given by this improved procedure. For 55 mph roads, the 2011 RDG procedure appears to lead to a LON sufficient to intercept between 80% and 90% of right-side departures that would otherwise strike a hazard located 10 m from the roadway. For hazards closer than 10 m, the 2011 RDG procedure intercepts progressively higher percentages of real-world departures. This suggests the protection level provided by the 2011 RDG procedure varies with the hazard offset, becoming more conservative as the hazard moves closer to the roadway. The improved procedure, by comparison, gives a consistent protection level regardless of hazard location. Copyright © 2015. Published by Elsevier Ltd.

Inundation Mapping and Hazard Assessment of Tectonic and Landslide Tsunamis in Southeast Alaska

NASA Astrophysics Data System (ADS)

Suleimani, E.; Nicolsky, D.; Koehler, R. D., III

2014-12-01

The Alaska Earthquake Center conducts tsunami inundation mapping for coastal communities in Alaska, and is currently focused on the southeastern region and communities of Yakutat, Elfin Cove, Gustavus and Hoonah. This activity provides local emergency officials with tsunami hazard assessment, planning, and mitigation tools. At-risk communities are distributed along several segments of the Alaska coastline, each having a unique seismic history and potential tsunami hazard. Thus, a critical component of our project is accurate identification and characterization of potential tectonic and landslide tsunami sources. The primary tectonic element of Southeast Alaska is the Fairweather - Queen Charlotte fault system, which has ruptured in 5 large strike-slip earthquakes in the past 100 years. The 1958 "Lituya Bay" earthquake triggered a large landslide into Lituya Bay that generated a 540-m-high wave. The M7.7 Haida Gwaii earthquake of October 28, 2012 occurred along the same fault, but was associated with dominantly vertical motion, generating a local tsunami. Communities in Southeast Alaska are also vulnerable to hazards related to locally generated waves, due to proximity of communities to landslide-prone fjords and frequent earthquakes. The primary mechanisms for local tsunami generation are failure of steep rock slopes due to relaxation of internal stresses after deglaciation, and failure of thick unconsolidated sediments accumulated on underwater delta fronts at river mouths. We numerically model potential tsunami waves and inundation extent that may result from future hypothetical far- and near-field earthquakes and landslides. We perform simulations for each source scenario using the Alaska Tsunami Model, which is validated through a set of analytical benchmarks and tested against laboratory and field data. Results of numerical modeling combined with historical observations are compiled on inundation maps and used for site-specific tsunami hazard assessment by emergency planners.

Fault-based PSHA of an active tectonic region characterized by low deformation rates: the case of the Lower Rhine Graben

NASA Astrophysics Data System (ADS)

Vanneste, Kris; Vleminckx, Bart; Camelbeeck, Thierry

2016-04-01

The Lower Rhine Graben (LRG) is one of the few regions in intraplate NW Europe where seismic activity can be linked to active faults, yet probabilistic seismic hazard assessments of this region have hitherto been based on area-source models, in which the LRG is modeled as a single or a small number of seismotectonic zones with uniform seismicity. While fault-based PSHA has become common practice in more active regions of the world (e.g., California, Japan, New Zealand, Italy), knowledge of active faults has been lagging behind in other regions, due to incomplete tectonic inventory, low level of seismicity, lack of systematic fault parameterization, or a combination thereof. The past few years, efforts are increasingly being directed to the inclusion of fault sources in PSHA in these regions as well, in order to predict hazard on a more physically sound basis. In Europe, the EC project SHARE ("Seismic Hazard Harmonization in Europe", http://www.share-eu.org/) represented an important step forward in this regard. In the frame of this project, we previously compiled the first parameterized fault model for the LRG that can be applied in PSHA. We defined 15 fault sources based on major stepovers, bifurcations, gaps, and important changes in strike, dip direction or slip rate. Based on the available data, we were able to place reasonable bounds on the parameters required for time-independent PSHA: length, width, strike, dip, rake, slip rate, and maximum magnitude. With long-term slip rates remaining below 0.1 mm/yr, the LRG can be classified as a low-deformation-rate structure. Information on recurrence interval and elapsed time since the last major earthquake is lacking for most faults, impeding time-dependent PSHA. We consider different models to construct the magnitude-frequency distribution (MFD) of each fault: a slip-rate constrained form of the classical truncated Gutenberg-Richter MFD (Anderson & Luco, 1983) versus a characteristic MFD following Youngs & Coppersmith (1985). The summed Anderson & Luco fault MFDs show a remarkably good agreement with the MFD obtained from the historical and instrumental catalog for the entire LRG, whereas the summed Youngs & Coppersmith MFD clearly underpredicts low to moderate magnitudes, but yields higher occurrence rates for M > 6.3 than would be obtained by simple extrapolation of the catalog MFD. The moment rate implied by the Youngs & Coppersmith MFDs is about three times higher, but is still within the range allowed by current GPS uncertainties. Using the open-source hazard engine OpenQuake (http://openquake.org/), we compute hazard maps for return periods of 475, 2475, and 10,000 yr, and for spectral periods of 0 s (PGA) and 1 s. We explore the impact of various parameter choices, such as MFD model, GMPE distance metric, and inclusion of a background zone to account for lower magnitudes, and we also compare the results with hazard maps based on area-source models. References: Anderson, J. G., and J. E. Luco (1983), Consequences of slip rate constraints on earthquake occurrence relations, Bull. Seismol. Soc. Am., 73(2), 471-496. Youngs, R. R., and K. J. Coppersmith (1985), Implications of fault slip rates and earthquake recurrence models to probabilistic seismic hazard estimates, Bull. Seismol. Soc. Am., 75(4), 939-964.

Probabilistic Seismic Hazard Assessment of the Chiapas State (SE Mexico)

NASA Astrophysics Data System (ADS)

Rodríguez-Lomelí, Anabel Georgina; García-Mayordomo, Julián

2015-04-01

The Chiapas State, in southeastern Mexico, is a very active seismic region due to the interaction of three tectonic plates: Northamerica, Cocos and Caribe. We present a probabilistic seismic hazard assessment (PSHA) specifically performed to evaluate seismic hazard in the Chiapas state. The PSHA was based on a composited seismic catalogue homogenized to Mw and was used a logic tree procedure for the consideration of different seismogenic source models and ground motion prediction equations (GMPEs). The results were obtained in terms of peak ground acceleration as well as spectral accelerations. The earthquake catalogue was compiled from the International Seismological Center and the Servicio Sismológico Nacional de México sources. Two different seismogenic source zones (SSZ) models were devised based on a revision of the tectonics of the region and the available geomorphological and geological maps. The SSZ were finally defined by the analysis of geophysical data, resulting two main different SSZ models. The Gutenberg-Richter parameters for each SSZ were calculated from the declustered and homogenized catalogue, while the maximum expected earthquake was assessed from both the catalogue and geological criteria. Several worldwide and regional GMPEs for subduction and crustal zones were revised. For each SSZ model we considered four possible combinations of GMPEs. Finally, hazard was calculated in terms of PGA and SA for 500-, 1000-, and 2500-years return periods for each branch of the logic tree using the CRISIS2007 software. The final hazard maps represent the mean values obtained from the two seismogenic and four attenuation models considered in the logic tree. For the three return periods analyzed, the maps locate the most hazardous areas in the Chiapas Central Pacific Zone, the Pacific Coastal Plain and in the Motagua and Polochic Fault Zone; intermediate hazard values in the Chiapas Batholith Zone and in the Strike-Slip Faults Province. The hazard decreases towards the northeast across the Reverse Faults Province and up to Yucatan Platform, where the lowest values are reached. We also produced uniform hazard spectra (UHS) for the three main cities of Chiapas. Tapachula city presents the highest spectral accelerations, while Tuxtla Gutierrez and San Cristobal de las Casas cities show similar values. We conclude that seismic hazard in Chiapas is chiefly controlled by the subduction of the Cocos beneath Northamerica and Caribe tectonic plates, that makes the coastal areas the most hazardous. Additionally, the Motagua and Polochic Fault Zones are also important, increasing the hazard particularly in southeastern Chiapas.

Seismic displacement of gently-sloping coastal and marine sediment under multidirectional earthquake loading

USGS Publications Warehouse

Kayen, Robert E.

2017-01-01

Gentle sediment-laden slopes are typical of the onshore coastal zone and offshore continental shelf and slope. Coastal sediment are commonly young weakly consolidated materials that are well stratified, have low strength, and can mobilize shear displacements at low levels of stress. Seismically-driven plastic displacements of these sediment pose a hazard to coastal cities, buried onshore utilities, and offshore infrastructure like harbor protection and outfalls. One-dimensional rigid downslope-directed Newmark sliding block analyses have been used to predict earthquake deformations generally on steeper slopes that are modeled as frictional materials. This study probes the effect of multidirectional earthquake motions on inertial displacements of gently sloping ground of the coastal and offshore condition where soft-compliant soil is expected. Toward that objective, this investigation seeks to understand the effect on Newmark-type displacements of [1] multidirectional earthquake shaking and [2] soil compliance. In order to model multidirectional effects, the earthquake motions are rotated into the local slope strike- and dip-components. On gently sloping ground, including the strike component of motion always results in a larger and more accurate shear stress vector. Strike motions are found to contribute to downslope deformations on any declivity. Compliant response of the soil mass also influences the plastic displacements. The magnitude of seismic displacements can be estimated with a simplified model using only the estimated soil yield-acceleration (ky) and the peak ground velocity (Vmax) of the earthquake motions. Compliance effects can be effectively mapped using the concept of Plastic Displacement Response Spectra (PDRS).

Statistical characteristics of transient enclosure voltage in ultra-high-voltage gas-insulated switchgear

NASA Astrophysics Data System (ADS)

Cai, Yuanji; Guan, Yonggang; Liu, Weidong

2017-06-01

Transient enclosure voltage (TEV), which is a phenomenon induced by the inner dielectric breakdown of SF6 during disconnector operations in a gas-insulated switchgear (GIS), may cause issues relating to shock hazard and electromagnetic interference to secondary equipment. This is a critical factor regarding the electromagnetic compatibility of ultra-high-voltage (UHV) substations. In this paper, the statistical characteristics of TEV at UHV level are collected from field experiments, and are analyzed and compared to those from a repeated strike process. The TEV waveforms during disconnector operations are recorded by a self-developed measurement system first. Then, statistical characteristics, such as the pulse number, duration of pulses, frequency components, magnitude and single pulse duration, are extracted. The transmission line theory is introduced to analyze the TEV and is validated by the experimental results. Finally, the relationship between the TEV and the repeated strike process is analyzed. This proves that the pulse voltage of the TEV is proportional to the corresponding breakdown voltage. The results contribute to the definition of the standard testing waveform of the TEV, and can aid the protection of electronic devices in substations by minimizing the threat of this phenomenon.

A Viscoelastic earthquake simulator with application to the San Francisco Bay region

USGS Publications Warehouse

Pollitz, Fred F.

2009-01-01

Earthquake simulation on synthetic fault networks carries great potential for characterizing the statistical patterns of earthquake occurrence. I present an earthquake simulator based on elastic dislocation theory. It accounts for the effects of interseismic tectonic loading, static stress steps at the time of earthquakes, and postearthquake stress readjustment through viscoelastic relaxation of the lower crust and mantle. Earthquake rupture initiation and termination are determined with a Coulomb failure stress criterion and the static cascade model. The simulator is applied to interacting multifault systems: one, a synthetic two-fault network, and the other, a fault network representative of the San Francisco Bay region. The faults are discretized both along strike and along dip and can accommodate both strike slip and dip slip. Stress and seismicity functions are evaluated over 30,000 yr trial time periods, resulting in a detailed statistical characterization of the fault systems. Seismicity functions such as the coefficient of variation and a- and b-values exhibit systematic patterns with respect to simple model parameters. This suggests that reliable estimation of the controlling parameters of an earthquake simulator is a prerequisite to the interpretation of its output in terms of seismic hazard.

The March 11, 2002 Masafi, United Arab Emirates Earthquake: Insights into the Seismotectonics of the Northern Oman Mountains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodgers, A; Fowler, A; Al-Amri, A

2005-04-26

A moderate (M{approx}5) earthquake struck the northeastern United Arab Emirates (UAE) and northern Oman on March 11, 2002. The event was felt over a wide area of the northern Emirates and was accompanied by smaller (felt) events before and after the March 11 main shock. The event was large enough to be detected and located by global networks at teleseismic distances. We estimated focal mechanism and depth from broadband complete regional waveform modeling. We report a normal mechanism with a slight right-lateral strike-slip component consistent with the large-scale tectonics. The normal component suggests relaxation of obducted crust of the Semailmore » Ophilite (specifically, the Khor Fakkan Block) while the right-lateral strike-slip component of the mechanism is consistent with shear across the Oman Line. Felt earthquakes are rare in the region, however no regional seismic network exists in the UAE to determine local seismicity. This event offers a unique opportunity to study the active tectonics of the region as well as inform future studies of seismic hazard in the UAE and northern Oman.« less

A Maxwell-Schrödinger solver for quantum optical few-level systems

NASA Astrophysics Data System (ADS)

Fleischhaker, Robert; Evers, Jörg

2011-03-01

The msprop program presented in this work is capable of solving the Maxwell-Schrödinger equations for one or several laser fields propagating through a medium of quantum optical few-level systems in one spatial dimension and in time. In particular, it allows to numerically treat systems in which a laser field interacts with the medium with both its electric and magnetic component at the same time. The internal dynamics of the few-level system is modeled by a quantum optical master equation which includes coherent processes due to optical transitions driven by the laser fields as well as incoherent processes due to decay and dephasing. The propagation dynamics of the laser fields is treated in slowly varying envelope approximation resulting in a first order wave equation for each laser field envelope function. The program employs an Adams predictor formula second order in time to integrate the quantum optical master equation and a Lax-Wendroff scheme second order in space and time to evolve the wave equations for the fields. The source function in the Lax-Wendroff scheme is specifically adapted to allow taking into account the simultaneous coupling of a laser field to the polarization and the magnetization of the medium. To reduce execution time, a customized data structure is implemented and explained. In three examples the features of the program are demonstrated and the treatment of a system with a phase-dependent cross coupling of the electric and magnetic field component of a laser field is shown. Program summaryProgram title: msprop Catalogue identifier: AEHR_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHR_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 507 625 No. of bytes in distributed program, including test data, etc.: 10 698 552 Distribution format: tar.gz Programming language: C (C99 standard), Mathematica, bash script, gnuplot script Computer: Tested on x86 architecture Operating system: Unix/Linux environment RAM: Less than 30 MB Classification: 2.5 External routines: Standard C math library, accompanying bash script uses gnuplot, bc (basic calculator), and convert (ImageMagick) Nature of problem: We consider a system of quantum optical few-level atoms exposed to several near-resonant continuous-wave or pulsed laser fields. The complexity of the problem arises from the combination of the coherent and incoherent time evolution of the atoms and its dependence on the spatially varying fields. In systems with a coupling to the electric and magnetic field component the simultaneous treatment of both field components poses an additional challenge. Studying the system dynamics requires solving the quantum optical master equation coupled to the wave equations governing the spatio-temporal dynamics of the fields [1,2]. Solution method: We numerically integrate the equations of motion using a second order Adams predictor method for the time evolution of the atomic density matrix and a second order Lax-Wendroff scheme for iterating the fields in space [3]. For the Lax-Wendroff scheme, the source function is adapted such that a simultaneous coupling to the polarization and the magnetization of the medium can be taken into account. Restrictions: The evolution of the fields is treated in slowly varying envelope approximation [2] such that variations of the fields in space and time must be on a scale larger than the wavelength and the optical cycle. Propagation is restricted to the forward direction and to one dimension. Concerning the description of the atomic system, only a finite number of basis states can be treated and the laser-driven transitions have to be near-resonant such that the rotating-wave approximation can be applied [2]. Unusual features: The program allows the dipole interaction of both the electric and the magnetic component of a laser field to be taken into account at the same time. Thus, a system with a phase-dependent cross coupling of electric and magnetic field component can be treated (see Section 4.2 and [4]). Concerning the implementation of the data structure, it has been optimized for faster memory access. Compared to using standard memory allocation methods, shorter run times are achieved (see Section 3.2). Additional comments: Three examples are given. They each include a readme file, a Mathematica notebook to generate the C-code form of the quantum optical master equation, a parameter file, a bash script which runs the program and converts the numerical data into a movie, two gnuplot scripts, and all files that are produced by running the bash script. Running time: For the first two examples the running time is less than a minute, the third example takes about 12 minutes. On a Pentium 4 (3 GHz) system, a rough estimate can be made with a value of 1 second per million grid points and per field variable.

Using Deep Slow Slip in New Zealand to Constrain Slip Partitioning

NASA Astrophysics Data System (ADS)

Bartlow, N. M.; Wallace, L. M.

2016-12-01

Underneath New Zealand's North Island, the Pacific plate subducts obliquely beneath the Australian plate. Just to the south, subduction ceases and the plate boundary transitions to the mainly strike-slip, steeply dipping Alpine fault that runs along the South Island. In the region of the southern North Island, the relative plate motion has significant components of both convergence and along strike motion, and slip is partitioned between the main Hikurangi subduction interface and a series of shallower strike-slip faults running thurough the North Island (Wallace and Beavan, GRL, 2010). This region also hosts deep ( 50 km), long duration ( 1 year) slow slip events (SSEs). From early 2013 to early 2016, continuous GPS stations maintained by GeoNet in this region recorded two such deep SSEs on the Hikurangi megathrust. The first SSE occurred on the Kapiti patch, just southwest of the North Island coast. SSEs previous occurred here in 2003 and 2008 (Wallace and Beavan, JGR, 2010). The 2014 Kapiti SSE is unique because it was rapidly decelerated following increased normal stress (clamping) caused by a nearby M 6.3 earthquake (Wallace et al., GRL, 2014). However, GPS data indicates that slip did not stop entirely, and soon after the Manawatu slow slip patch just to the northeast ruptured in another SSE. This patch previously had large SSEs in 2004/2005 and 2010/2011. Given the previous repeat interval of 5.5 years, the 2014/2015 Manawatu SSE is early; however, the record is very short. Here we show Network Inversion Filter derived models of slow slip for the various phases of the Kapiti and Manawatu SSEs, which indicate a possible continuous migration of slip from the Kapiti SSE patch to the Manawatu SSE patch, and we quantify the shear stress increase on the Manawatu patch after the Kapiti SSE. Additionally, we explore allowing the Network Inversion Filter to vary the direction of slip on the plate interface to better fit the data. We estimate how much of the strike-slip and dip-slip components of the relative plate motion are being accommodated by the main thrust interface, and infer how much slip is being accommodated by the strike-slip faults and forearc rotation. We compare our results to those from prior block models of inter-SSE data (Wallace et al., G3, 2009) and explore the implications for seismic hazard assessment in this region.

Evaluation of Alternative Seismic Source Characterization Models for the Inner Borderlands of Southern California

NASA Astrophysics Data System (ADS)

Hanson, K. L.; Angell, M.; Foxall, W.; Rietman, J.

2002-12-01

Alternative source characterizations for seismic hazard analysis are developed to capture the range of plausible fault geometries and interactions between postulated thrusts (i.e., the Oceanside blind thrust (OBT) and San Joaquin Hills blind fault (SJBF)) and strike-slip faults (Rose Canyon (RC)-Newport Inglewood (NI) faults) along the Southern California inner borderlands. Evaluation of 2D and high-resolution shallow seismic data show evidence for a relatively continuous zone of deformation (OZD) linking the RC and NI, both of which are active strike-slip faults, based on seismicity and paleoseismic data. Geodetic data are consistent with NNW-shear and show little or no convergence across the inner borderland, or evidence of a regional "driving" force that would reactivate a large seismogenic thrust (see Moriwaki and others, this volume). Fault and fold deformation observed along the OZD between the RC and NI is consistent with transpressional right lateral slip along a N20W-trending fault zone. Evidence to support reactivation of the entire OBT in the current tectonic environment is not demonstrated. Seismicity and possible late Pleistocene/Holocene reverse faults and associated folding can be explained by localized contraction in left steps or bends in a transpressional right-slip tectonic environment. Clockwise rotation of crustal blocks in the inner borderland (which is not inconsistent with geodetic data suggesting a component of extension across the southern inner borderland) could account for the greater intensity of contractional structures in the hanging wall of the northern OBT west of the OZD. This might explain the local reactivation of portions of the OBT, but would not require reactivation of the entire detachment. Much of the contractional deformation observed in the inner borderland (e.g., the San Mateo thrust belt) could have occurred during the Pliocene. Regional coastal uplift, which has been cited as evidence that the Oceanside and Thirtymile Bank thrusts are active on a regional basis, may be attributed to other processes, such as rift shoulder thermal isostasy (e.g., Kier et.al, Tectonics 2002). We present relative weights for three alternative source models that consider a throughgoing strike-slip fault system (inactive OBT), a regional blind thrust (OBT), or an oblique fault in which strain is partitioned updip onto a strike-slip (offshore strike-slip fault) and reactivated thrust (OBT).

New insights into the active deformation of accretionary prisms: examples from the Western Makran, Iran

NASA Astrophysics Data System (ADS)

Penney, Camilla; Copley, Alex; Oveisi, Benham

2016-04-01

The Makran subduction zone, along the southern coasts of Iran and Pakistan, hosts one of the largest exposed accretionary wedges in the world. The western Makran has been characterised by a lack of shallow and thrust seismicity in both the instrumental and historical periods. The Mw 6.1 2013 Minab earthquake thus provides a rare opportunity to study the deformation of the accretionary wedge in the transition region between continent-continent collision, in the Zagros, and oceanic subduction, in the Makran. We study the source parameters and slip distribution of this earthquake using seismology, geodesy and field observations. We observe left-lateral strike-slip motion on a fault striking ENE-WSW; approximately perpendicular to the faults of the Minab-Zendan-Palami fault zone, the main structure previously thought to accommodate the right-lateral shear between the Zagros and the Makran. The fault that ruptured in 2013 is one of a series of approximately E-W striking left-lateral faults visible in the geology and geomorphology. These accommodate a velocity field equivalent to right-lateral shear on N-S striking planes by clockwise rotations about vertical axes. The longitudinal range of shear in the western Makran is likely to be controlled by the distance over which the underthrusting Arabian lithosphere deepens in the transition from continent-continent collision to oceanic subduction. The lack of observed megathrust seismicity in the western Makran has led to assertions that the convergence in this region may be aseismic, in contrast to the eastern Makran, which experienced an Mw8.1 earthquake in 1945. The right-lateral Sistan Suture Zone, which runs ~N-S along the Iran-Afghanistan border to the north of the Makran, appears to separate these regimes. However, right-lateral faulting is not observed south of ~27°N, within the wedge. The Minab earthquake and the 2013 Balochistan earthquake show that the Makran accretionary wedge is dominated by strike-slip faulting. By combining GPS, seismology and satellite imagery we assess possible kinematic scenarios for the accommodation of right-lateral motion in the Makran accretionary wedge, and their implications for earthquake hazard in the western Makran, and the dynamics of accretionary wedge deformation in general.

Behavioral traits and airport type affect mammal incidents with U.S. civil aircraft.

PubMed

Schwarz, Kristin B; Belant, Jerrold L; Martin, James A; DeVault, Travis L; Wang, Guiming

2014-10-01

Wildlife incidents with aircraft cost the United States (U.S.) civil aviation industry >US$1.4 billion in estimated damages and loss of revenue from 1990 to 2009. Although terrestrial mammals represented only 2.3 % of wildlife incidents, damage to aircraft occurred in 59 % of mammal incidents. We examined mammal incidents (excluding bats) at all airports in the Federal Aviation Administration (FAA) National Wildlife Strike Database from 1990 to 2010 to characterize these incidents by airport type: Part-139 certified (certificated) and general aviation (GA). We also calculated relative hazard scores for species most frequently involved in incidents. We found certificated airports had more than twice as many incidents as GA airports. Incidents were most frequent in October (n = 215 of 1,764 total) at certificated airports and November (n = 111 of 741 total) at GA airports. Most (63.2 %) incidents at all airports (n = 1,523) occurred at night but the greatest incident rate occurred at dusk (177.3 incidents/hr). More incidents with damage (n = 1,594) occurred at GA airports (38.6 %) than certificated airports (19.0 %). Artiodactyla (even-toed ungulates) incidents incurred greatest (92.4 %) damage costs (n = 326; US$51.8 million) overall and mule deer (Odocoileus hemionus) was the most hazardous species. Overall, relative hazard score increased with increasing log body mass. Frequency of incidents was influenced by species relative seasonal abundance and behavior. We recommend airport wildlife officials evaluate the risks mammal species pose to aircraft based on the hazard information we provide and consider prioritizing management strategies that emphasize reducing their occurrence on airport property.

Behavioral Traits and Airport Type Affect Mammal Incidents with U.S. Civil Aircraft

NASA Astrophysics Data System (ADS)

Schwarz, Kristin B.; Belant, Jerrold L.; Martin, James A.; DeVault, Travis L.; Wang, Guiming

2014-10-01

Wildlife incidents with aircraft cost the United States (U.S.) civil aviation industry >US1.4 billion in estimated damages and loss of revenue from 1990 to 2009. Although terrestrial mammals represented only 2.3 % of wildlife incidents, damage to aircraft occurred in 59 % of mammal incidents. We examined mammal incidents (excluding bats) at all airports in the Federal Aviation Administration (FAA) National Wildlife Strike Database from 1990 to 2010 to characterize these incidents by airport type: Part-139 certified (certificated) and general aviation (GA). We also calculated relative hazard scores for species most frequently involved in incidents. We found certificated airports had more than twice as many incidents as GA airports. Incidents were most frequent in October ( n = 215 of 1,764 total) at certificated airports and November ( n = 111 of 741 total) at GA airports. Most (63.2 %) incidents at all airports ( n = 1,523) occurred at night but the greatest incident rate occurred at dusk (177.3 incidents/hr). More incidents with damage ( n = 1,594) occurred at GA airports (38.6 %) than certificated airports (19.0 %). Artiodactyla (even-toed ungulates) incidents incurred greatest (92.4 %) damage costs ( n = 326; US51.8 million) overall and mule deer ( Odocoileus hemionus) was the most hazardous species. Overall, relative hazard score increased with increasing log body mass. Frequency of incidents was influenced by species relative seasonal abundance and behavior. We recommend airport wildlife officials evaluate the risks mammal species pose to aircraft based on the hazard information we provide and consider prioritizing management strategies that emphasize reducing their occurrence on airport property.

Monitoring the Dead Sea Region by Multi-Parameter Stations

NASA Astrophysics Data System (ADS)

Mohsen, A.; Weber, M. H.; Kottmeier, C.; Asch, G.

2015-12-01

The Dead Sea Region is an exceptional ecosystem whose seismic activity has influenced all facets of the development, from ground water availability to human evolution. Israelis, Palestinians and Jordanians living in the Dead Sea region are exposed to severe earthquake hazard. Repeatedly large earthquakes (e.g. 1927, magnitude 6.0; (Ambraseys, 2009)) shook the whole Dead Sea region proving that earthquake hazard knows no borders and damaging seismic events can strike anytime. Combined with the high vulnerability of cities in the region and with the enormous concentration of historical values this natural hazard results in an extreme earthquake risk. Thus, an integration of earthquake parameters at all scales (size and time) and their combination with data of infrastructure are needed with the specific aim of providing a state-of-the-art seismic hazard assessment for the Dead Sea region as well as a first quantitative estimate of vulnerability and risk. A strong motivation for our research is the lack of reliable multi-parameter ground-based geophysical information on earthquakes in the Dead Sea region. The proposed set up of a number of observatories with on-line data access will enable to derive the present-day seismicity and deformation pattern in the Dead Sea region. The first multi-parameter stations were installed in Jordan, Israel and Palestine for long-time monitoring. All partners will jointly use these locations. All stations will have an open data policy, with the Deutsches GeoForschungsZentrum (GFZ, Potsdam, Germany) providing the hard and software for real-time data transmission via satellite to Germany, where all partners can access the data via standard data protocols.

ARISTOTLE (All Risk Integrated System TOward The hoListic Early-warning): a multi-hazard expert advice system for the EU disaster response

NASA Astrophysics Data System (ADS)

Michelini, A.; Wotawa, G.; Arnold-Arias, D.

2017-12-01

ARISTOTLE (http://aristotle.ingv.it/) is a Pilot Project funded by the DG ECHO (EU Humanitarian Aid and Civil Protection) that provides expert scientific advice on natural disasters around the world that may cause a country to seek international help to the EU's Emergency Response Coordination Centre (ERCC) and, consequently, to the Union Civil Protection Mechanism Participating States. The EU is committed to providing disaster response in a timely and efficient manner and to ensure European assistance meets the real needs in the population affected, whether in Europe or beyond. When a disaster strikes, every minute counts for saving lives and rapid, coordinated and pre-planned response is essential. The ARISTOTLE consortium includes 15 partner institutions (11 from EU Countries; 2 from non-EU countries and 2 European organizations) operating in the Meteorological and Geophysical domains. The project coordination is shared among INGV and ZAMG for the geophysical and meteorological communities, respectively. ARISTOTLE harnesses operational expertise from across Europe to form a multi-hazard perspective on natural disasters related to volcanoes, earthquake (and resulting tsunami), severe weather and flooding. Each Hazard Group brings together experts from the particular hazard domain to deliver a `collective analysis' which is then fed into the partnership multi-hazard discussions. Primary target of the pilot project has been the prototyping and the implementation of a scalable system (in terms of number of partners and hazards) capable of providing to ERCC the sought advice. To this end, the activities of the project have been focusing on the establishment of a "Multi-Hazard Operational Board" that is assigned the 24*7 operational duty regulated by a "Standard Operating Protocol" and the implementation of a dedicated IT platform to assembly the resulting reports. The project has reached the point where the routine and emergency advice services are being provided and will continue until the end of the project in January 2018. The presentation will illustrate the different modes of operation envisaged and the status and the solutions found by the project consortium to respond to the ERCC requirements.

Thermal state of the Explorer segment of the Cascadia subduction zone: Implications for seismic and tsunami hazards

NASA Astrophysics Data System (ADS)

Gao, Dawei; Wang, Kelin; Davis, Earl E.; Jiang, Yan; Insua, Tania L.; He, Jiangheng

2017-04-01

The Explorer segment of northernmost Cascadia is an end-member "warm" subduction zone with very young incoming plate and slow-convergence rate. Understanding the megathrust earthquake potential of this type of subduction zone is of both geodynamic and societal importance. Available geodetic observations indicate that the subduction megathrust of the Explorer segment is currently locked to some degree, but the downdip extent of the fault area that is potentially seismogenic is not known. Here we construct finite-element models to estimate the thermally allowed megathrust seismogenic zone, using available knowledge of regional plate kinematics, structural data, and heat flow observations as constraints. Despite ambiguities in plate interface geometry constrained by hypocenter locations of low-frequency earthquakes beneath Vancouver Island, the thermal models suggest a potential rupture zone of ˜60 km downdip width located fully offshore. Using dislocation modeling, we further illustrate that a rupture zone of this size, even with a conservative assumption of ˜100 km strike length, can cause significant tsunami-genic deformation. Future seismic and tsunami hazard assessment in northern Cascadia must take the Explorer segment into account.

Efforts to monitor and characterize the recent increasing seismicity in central Oklahoma

USGS Publications Warehouse

McNamara, Daniel E.; Rubinstein, Justin L.; Myers, Emma; Smoczyk, Gregory M.; Benz, Harley M.; Williams, Robert; Hayes, Gavin; Wilson, David; Herrmann, Robert B.; McMahon, Nicole D; Aster, R.C.; Bergman, E.; Holland, Austin; Earle, Paul

2015-01-01

The sharp increase in seismicity over a broad region of central Oklahoma has raised concerns regarding the source of the activity and its potential hazard to local communities and energy-industry infrastructure. Efforts to monitor and characterize the earthquake sequences in central Oklahoma are reviewed. Since early 2010, numerous organizations have deployed temporary portable seismic stations in central Oklahoma to record the evolving seismicity. A multiple-event relocation method is applied to produce a catalog of central Oklahoma earthquakes from late 2009 into early 2015. Regional moment tensor (RMT) source parameters were determined for the largest and best-recorded earthquakes. Combining RMT results with relocated seismicity enabled determination of the length, depth, and style of faulting occurring on reactivated subsurface fault systems. It was found that the majority of earthquakes occur on near-vertical, optimally oriented (northeast-southwest and northwest-southeast) strike-slip faults in the shallow crystalline basement. In 2014, 17 earthquakes occurred with magnitudes of 4 or larger. It is suggested that these recently reactivated fault systems pose the greatest potential hazard to the region.

Lightning-associated deaths--United States, 1980-1995.

PubMed

1998-05-22

A lightning strike can cause death or various injuries to one or several persons. The mechanism of injury is unique, and the manifestations differ from those of other electrical injuries. In the United States, lightning causes more deaths than do most other natural hazards (e.g., hurricanes and tornadoes), although the incidence of lightning-related deaths has decreased since the 1950s. The cases described in this report illustrate diverse circumstances in which deaths attributable to lightning can occur. This report also summarizes data from the Compressed Mortality File of CDC's National Center for Health Statistics on lightning fatalities in the United States from 1980 through 1995, when 1318 deaths were attributed to lightning.

Contradicting Estimates of Location, Geometry, and Rupture History of Highly Active Faults in Central Japan

NASA Astrophysics Data System (ADS)

Okumura, K.

2011-12-01

Accurate location and geometry of seismic sources are critical to estimate strong ground motion. Complete and precise rupture history is also critical to estimate the probability of the future events. In order to better forecast future earthquakes and to reduce seismic hazards, we should consider over all options and choose the most likely parameter. Multiple options for logic trees are acceptable only after thorough examination of contradicting estimates and should not be a result from easy compromise or epoche. In the process of preparation and revisions of Japanese probabilistic and deterministic earthquake hazard maps by Headquarters for Earthquake Research Promotion since 1996, many decisions were made to select plausible parameters, but many contradicting estimates have been left without thorough examinations. There are several highly-active faults in central Japan such as Itoigawa-Shizuoka Tectonic Line active fault system (ISTL), West Nagano Basin fault system (WNBF), Inadani fault system (INFS), and Atera fault system (ATFS). The highest slip rate and the shortest recurrence interval are respectively ~1 cm/yr and 500 to 800 years, and estimated maximum magnitude is 7.5 to 8.5. Those faults are very hazardous because almost entire population and industries are located above the fault within tectonic depressions. As to the fault location, most uncertainties arises from interpretation of geomorphic features. Geomorphological interpretation without geological and structural insight often leads to wrong mapping. Though non-existent longer fault may be a safer estimate, incorrectness harm reliability of the forecast. Also this does not greatly affect strong motion estimates, but misleading to surface displacement issues. Fault geometry, on the other hand, is very important to estimate intensity distribution. For the middle portion of the ISTL, fast-moving left-lateral strike-slip up to 1 cm/yr is obvious. Recent seismicity possibly induced by 2011 Tohoku earthquake show pure strike-slip. However, thrusts are modeled from seismic profiles and gravity anomalies. Therefore, two contradicting models are presented for strong motion estimates. There should be a unique solution of the geometry, which will be discussed. As to the rupture history, there is plenty of paleoseismological evidence that supports segmentation of those faults above. However, in most fault zones, the largest and sometimes possibly less frequent earthquakes are modeled. Segmentation and modeling of coming earthquakes should be more carefully examined without leaving them in contradictions.

ARISTOTLE (All Risk Integrated System TOwards The hoListic Early-warning)

NASA Astrophysics Data System (ADS)

Michelini, Alberto; Wotawa, Gerhard; Arnold-Arias, Delia

2017-04-01

The Emergency Response Coordination Centre (ERCC) is the EU coordination office for humanitarian aid and civil protection operations of DG ECHO (EU Humanitarian Aid and Civil Protection). ERCC needs rapidly authoritative multi-hazard scientific expertise and analysis on 24*7 basis since, when a disaster strikes, every minute counts for saving lives and immediate, coordinated and pre-planned response is essential. The EU is committed to providing disaster response in a timely and efficient manner and to ensure European assistance meets the real needs in the population affected, whether in Europe or beyond. The ARISTOTLE consortium was awarded the European Commission's DG ECHO "Pilot project in the area of Early Warning System for natural disasters" (OJ 2015 S/154-283349). The tender articulates the needs and expectations of DG ECHO in respect of the provision of multi-hazard advice to the Emergency Response & Coordination Centre in Brussels. Specifically, the tender aims to fill the gap in knowledge that exists in the: • first 3 hours immediately after an event that has the potential to require a country to call on international help • provision of longer term advice following an emergency • provision of advice when a potential hazardous event is starting to form; this will usually be restricted to severe weather and flooding events and when possible to volcanic events. The ARISTOTLE Consortium was awarded the tender and the project effectively started on February 1st, 2016, for a duration of 2 years. ARISTOTLE (aristotle.ingv.it) is a multi-hazard partnership created by combining expertise from of total of 5 hazard groups [4 main hazard groups plus a sub-hazard - Severe Weather, Floods, Volcanos (only for ashes and gases hazard deriving from eruptions), Earthquakes and the related Tsunamis as a sub-hazard given its peculiarities and potential huge impact]. Each Hazard Group brings together experts from the particular hazard domain to deliver a 'collective analysis' which is then fed into the partnership multi-hazard discussions. The hazards are very different and have very diverse timelines for phenomenological occurrence (Figure 1). The ARISTOTLE consortium includes 15 partner institutions (11 from EU Countries; 2 from non-EU countries and 2 European organizations) operating in the Meteorological and Geophysical domains. The project coordination is shared among INGV and ZAMG for the geophysical and meteorological communities, respectively. Primary target of the tender project is the prototyping and the implementation of a scalable system (in terms of number of partners and hazards) capable of providing to ERCC the "desiderata" above. To this end, the activities of the project have been focusing on the establishment of a multi-hazard operational board (MHOB) that is assigned the 24*7 operational duty regulated by a "Standard Operating Protocol". The presentation will illustrate the different modes of operation envisaged and the status and the solutions found by the project consortium to respond to the ERCC requirements.

Earthquake Forecasting System in Italy

NASA Astrophysics Data System (ADS)

Falcone, G.; Marzocchi, W.; Murru, M.; Taroni, M.; Faenza, L.

2017-12-01

In Italy, after the 2009 L'Aquila earthquake, a procedure was developed for gathering and disseminating authoritative information about the time dependence of seismic hazard to help communities prepare for a potentially destructive earthquake. The most striking time dependency of the earthquake occurrence process is the time clustering, which is particularly pronounced in time windows of days and weeks. The Operational Earthquake Forecasting (OEF) system that is developed at the Seismic Hazard Center (Centro di Pericolosità Sismica, CPS) of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) is the authoritative source of seismic hazard information for Italian Civil Protection. The philosophy of the system rests on a few basic concepts: transparency, reproducibility, and testability. In particular, the transparent, reproducible, and testable earthquake forecasting system developed at CPS is based on ensemble modeling and on a rigorous testing phase. Such phase is carried out according to the guidance proposed by the Collaboratory for the Study of Earthquake Predictability (CSEP, international infrastructure aimed at evaluating quantitatively earthquake prediction and forecast models through purely prospective and reproducible experiments). In the OEF system, the two most popular short-term models were used: the Epidemic-Type Aftershock Sequences (ETAS) and the Short-Term Earthquake Probabilities (STEP). Here, we report the results from OEF's 24hour earthquake forecasting during the main phases of the 2016-2017 sequence occurred in Central Apennines (Italy).

On the link between media coverage of anorexia and pro-anorexic practices on the web.

PubMed

Yom-Tov, Elad; Boyd, Danah M

2014-03-01

Links between media portrayals of celebrities and participation in activities related to anorexia are of interest to both researchers and practitioners but are difficult to study over long time periods and in large populations. Here we aim to determine the links between media portrayals of celebrities and online practices related to anorexia. We examined the Internet searching activities of 9.2 million people, focusing on searches related to known celebrities, especially those perceived by the public as suffering from anorexia, and on searches indicative of anorexic practices. Additionally, we tracked media attention of individual celebrities by monitoring all messages from Twitter related to those celebrities. We found that a subset of users focus their browsing activities on celebrities perceived as anorexic. There was an increase of 14% in the hazard of performing anorexia-related searches after searching for information on the celebrities most perceived as anorexic. Media attention of a celebrity was a trigger for search activity, and when focused on a celebrity perceived as anorexic, resulted in a 33% increase in hazard for carrying out anorexic searches. Strikingly, when media attention included a reference to anorexia, the hazard decreased by 22%. Our findings suggest that it would be beneficial for media, when reporting on those celebrities who are known to suffer from anorexia, to include this information in their reporting. Copyright © 2013 Wiley Periodicals, Inc.

Environment, health, and gender in Latin America: trends and research issues.

PubMed

Wasserman, E

1999-04-01

Over the past several decades, Latin America underwent rapid urbanization, a demographic shift led by women. Women now make up almost half of the economically active population and the feminization of urban poverty is being reported as well. The majority of men and women now work in unregulated, unorganized "informal" and nontraditional industries and services lacking occupational and environmental regulations. There is a marked paucity of health studies examining possible hazardous exposures, especially where gender-based social etiologies are concerned. This is true even in concentrated industries such as manufacturing assembly plants and in potentially hazardous occupations in mining and nontraditional agricultural exports, for which data from other disciplines are available and raise serious concerns. The need to ensure enough jobs at sufficient levels of income to alleviate poverty will remain a major challenge at the turn of the century and the environmental health implications of doing so could be far-reaching. What data are available and, more strikingly, the paucity of published epidemiologic studies warrant deep concern and support calls for urgent, multidisciplinary research into the health effects of the combined, multiple assaults of hazardous industrial waste, inadequate water and sewage treatment, and occupational exposures. Given the complex and varied work roles of women, the information reviewed also points to the need to conduct such research in the region within a social-etiologic framework of gender analysis. Copyright 1999 Academic Press.

Landquake dynamics inferred from seismic source inversion: Greenland and Sichuan events of 2017

NASA Astrophysics Data System (ADS)

Chao, W. A.

2017-12-01

In June 2017 two catastrophic landquake events occurred in Greenland and Sichuan. The Greenland event leads to tsunami hazard in the small town of Nuugaarsiaq. A landquake in Sichuan hit the town, which resulted in over 100 death. Both two events generated the strong seismic signals recorded by the real-time global seismic network. I adopt an inversion algorithm to derive the landquake force time history (LFH) using the long-period waveforms, and the landslide volume ( 76 million m3) can be rapidly estimated, facilitating the tsunami-wave modeling for early warning purpose. Based on an integrated approach involving tsunami forward simulation and seismic waveform inversion, this study has significant implications to issuing actionable warnings before hazardous tsunami waves strike populated areas. Two single-forces (SFs) mechanism (two block model) yields the best explanation for Sichuan event, which demonstrates that secondary event (seismic inferred volume: 8.2 million m3) may be mobilized by collapse-mass hitting from initial rock avalanches ( 5.8 million m3), likely causing a catastrophic disaster. The later source with a force magnitude of 0.9967×1011 N occurred 70 seconds after first mass-movement occurrence. In contrast, first event has the smaller force magnitude of 0.8116×1011 N. In conclusion, seismically inferred physical parameters will substantially contribute to improving our understanding of landquake source mechanisms and mitigating similar hazards in other parts of the world.

Tsunami Defense Efforts at Samcheok Port, Korea

NASA Astrophysics Data System (ADS)

Cho, Y. S.

2016-02-01

Tsunamis mainly triggered by impulsive undersea motions are long waves and can propagate a long distance. Thus, they can cause huge casualties not only neighboring countries but also distant countries. Recently, several devastating tsunamis have been occurred around the Pacific Ocean rim. Among them, the Great East Japan tsunami occurred on March 11, 2011 is probably recorded as one of the most destructive tsunamis during last several decades. The Tsunami killed more than 20,000 people (including missing people) and deprived of property damage of approximately 300 billion USD. The eastern coast of the Korean Peninsula has been attacked historically by unexpected tsunami events. These tsunamis were generated by undersea earthquakes occurred off the west coast of Japan. For example, the Central East Sea Tsunami occurred on May 26, 1983 killed 3 people and caused serious property damage at Samcheok Port located at the eastern coast of Korea. Thus, a defense plan against unexpected tsunami strikes is an essential task for the port authority to protect lives of human beings and port facilities. In this study, a master plan of tsunami defense is introduced at Samcheok Port. A tsunami hazard map is also made by employing both propagation and inundation models. Detailed defense efforts are described including the procedure of development of a tsunami hazard map. Keywords: tsunami, hazard map, run-up height, emergency action plan

From MODFLOW-96 to MODFLOW-2005, ParFlow and Others: Updates and a Workflow for Up- and Out- Conversion

NASA Astrophysics Data System (ADS)

Pierce, S. A.; Hardesty Lewis, D.

2017-12-01

MODFLOW (MF) has served for decades as a de facto standard for groundwater modelling. Despite successive versions, legacy MF-96 simulations are still commonly encountered cases. Such is the case for many of the groundwater availability models of the State of Texas. Unfortunately, even the existence of converters to MF's newer versions has not necessarily stimulated their adoption, let alone re-creation of legacy models. This state of affairs may be due to the unfamiliarity of the modeller with the terminal or the FORTRAN programming language, resulting in an inability to address the minor or major bugs, nuances, or limitations in compilation or execution of the conversion programs. Here, we present a workflow that addresses the above intricacies all the while attempting to maintain portability in implementation. This workflow is contructed in the form of a Bash script and - with the geoscience-oriented in mind - re-presented as a Jupyter notebook. First, one may choose whether this executable will run with POSIX-compliance or with a preference towards the Bash facilities, both widely adopted by operating systems. In the same vein, it attempts to function within minimal command environments, which reduces any dependencies. Finally, it is designed to offer parallelism across as many cores and nodes as necessary or as few as desired, whether upon a personal or super-computer. Underlying this workflow are patches such that antiquated tools may compile and execute upon modern hardware. Also, fixes to long-standing bugs and limitations in the existing MF converters have been prepared. Specifically, support for the conversion of -96- and Horizontal Flow Barrier-coupled simulations has been added. More radically, we have laid the foundations of a conversion utility between MF and a similar modeller, ParFlow. Furthermore, the modular approach followed may extend to an application which inter-operates between arbitrary groundwater simulators. In short, an accessible and portable workflow of the process of up-conversion between MODFLOW versions now avails itself to geoscientists. Updated programs within it may allow for re-use, in whole or in part, legacy simulations. Lastly, a generic inter-operator has been established, invoking the possibility of significant ease in the recycling of groundwater data in the future.

Documentation for Initial Seismic Hazard Maps for Haiti

USGS Publications Warehouse

Frankel, Arthur; Harmsen, Stephen; Mueller, Charles; Calais, Eric; Haase, Jennifer

2010-01-01

In response to the urgent need for earthquake-hazard information after the tragic disaster caused by the moment magnitude (M) 7.0 January 12, 2010, earthquake, we have constructed initial probabilistic seismic hazard maps for Haiti. These maps are based on the current information we have on fault slip rates and historical and instrumental seismicity. These initial maps will be revised and improved as more data become available. In the short term, more extensive logic trees will be developed to better capture the uncertainty in key parameters. In the longer term, we will incorporate new information on fault parameters and previous large earthquakes obtained from geologic fieldwork. These seismic hazard maps are important for the management of the current crisis and the development of building codes and standards for the rebuilding effort. The boundary between the Caribbean and North American Plates in the Hispaniola region is a complex zone of deformation. The highly oblique ~20 mm/yr convergence between the two plates (DeMets and others, 2000) is partitioned between subduction zones off of the northern and southeastern coasts of Hispaniola and strike-slip faults that transect the northern and southern portions of the island. There are also thrust faults within the island that reflect the compressional component of motion caused by the geometry of the plate boundary. We follow the general methodology developed for the 1996 U.S. national seismic hazard maps and also as implemented in the 2002 and 2008 updates. This procedure consists of adding the seismic hazard calculated from crustal faults, subduction zones, and spatially smoothed seismicity for shallow earthquakes and Wadati-Benioff-zone earthquakes. Each one of these source classes will be described below. The lack of information on faults in Haiti requires many assumptions to be made. These assumptions will need to be revisited and reevaluated as more fieldwork and research are accomplished. We made two sets of maps using different assumptions about site conditions. One set of maps is for a firm-rock site condition (30-m averaged shear-wave velocity, Vs30, of 760 m/s). We also developed hazard maps that contain site amplification based on a grid of Vs30 values estimated from topographic slope. These maps take into account amplification from soils. We stress that these new maps are designed to quantify the hazard for Haiti; they do not consider all the sources of earthquake hazard that affect the Dominican Republic and therefore should not be considered as complete hazard maps for eastern Hispaniola. For example, we have not included hazard from earthquakes in the Mona Passage nor from large earthquakes on the subduction zone interface north of Puerto Rico. Furthermore, they do not capture all the earthquake hazards for eastern Cuba.

An L-band interferometric synthetic aperture radar study on the Ganos section of the north Anatolian fault zone between 2007 and 2011: Evidence for along strike segmentation and creep in a shallow fault patch.

PubMed

de Michele, Marcello; Ergintav, Semih; Aochi, Hideo; Raucoules, Daniel

2017-01-01

We utilize L-band interferometric synthetic aperture radar (InSAR) data in this study to retrieve a ground velocity map for the near field of the Ganos section of the north Anatolian fault (NAF) zone. The segmentation and creep distribution of this section, which last ruptured in 1912 to generate a moment magnitude (Mw)7.3 earthquake, remains incompletely understood. Because InSAR processing removes the mean orbital plane, we do not investigate large scale displacements due to regional tectonics in this study as these can be determined using global positioning system (GPS) data, instead concentrating on the close-to-the-fault displacement field. Our aim is to determine whether, or not, it is possible to retrieve robust near field velocity maps from stacking L-band interferograms, combining both single and dual polarization SAR data. In addition, we discuss whether a crustal velocity map can be used to complement GPS observations in an attempt to discriminate the present-day surface displacement of the Ganos fault (GF) across multiple segments. Finally, we characterize the spatial distribution of creep on shallow patches along multiple along-strike segments at shallow depths. Our results suggest the presence of fault segmentation along strike as well as creep on the shallow part of the fault (i.e. the existence of a shallow creeping patch) or the presence of a smoother section on the fault plane. Data imply a heterogeneous fault plane with more complex mechanics than previously thought. Because this study improves our knowledge of the mechanisms underlying the GF, our results have implications for local seismic hazard assessment.

Active faulting, earthquakes, and restraining bend development near Kerman city in southeastern Iran

NASA Astrophysics Data System (ADS)

Walker, Richard Thomas; Talebian, Morteza; Saiffori, Sohei; Sloan, Robert Alastair; Rasheedi, Ali; MacBean, Natasha; Ghassemi, Abbas

2010-08-01

We provide descriptions of strike-slip and reverse faulting, active within the late Quaternary, in the vicinity of Kerman city in southeastern Iran. The faults accommodate north-south, right-lateral, shear between central Iran and the Dasht-e-Lut depression. The regions that we describe have been subject to numerous earthquakes in the historical and instrumental periods, and many of the faults that are documented in this paper constitute hazards for local populations, including the city of Kerman itself (population ˜200,000). Faults to the north and east of Kerman are associated with the transfer of slip from the Gowk to the Kuh Banan right-lateral faults across a 40 km-wide restraining bend. Faults south and west of the city are associated with oblique slip on the Mahan and Jorjafk systems. The patterns of faulting observed along the Mahan-Jorjafk system, the Gowk-Kuh Banan system, and also the Rafsanjan-Rayen system further to the south, appear to preserve different stages in the development of these oblique-slip fault systems. We suggest that the faulting evolves through time. Topography is initially generated on oblique slip faults (as is seen on the Jorjafk fault). The shortening component then migrates to reverse faults situated away from the high topography whereas strike-slip continues to be accommodated in the high, mountainous, regions (as is seen, for example, on the Rafsanjan fault). The reverse faults may then link together and eventually evolve into new, through-going, strike-slip faults in a process that appears to be occurring, at present, in the bend between the Gowk and Kuh Banan faults.

An L-band interferometric synthetic aperture radar study on the Ganos section of the north Anatolian fault zone between 2007 and 2011: Evidence for along strike segmentation and creep in a shallow fault patch

PubMed Central

Ergintav, Semih; Aochi, Hideo; Raucoules, Daniel

2017-01-01

We utilize L-band interferometric synthetic aperture radar (InSAR) data in this study to retrieve a ground velocity map for the near field of the Ganos section of the north Anatolian fault (NAF) zone. The segmentation and creep distribution of this section, which last ruptured in 1912 to generate a moment magnitude (Mw)7.3 earthquake, remains incompletely understood. Because InSAR processing removes the mean orbital plane, we do not investigate large scale displacements due to regional tectonics in this study as these can be determined using global positioning system (GPS) data, instead concentrating on the close-to-the-fault displacement field. Our aim is to determine whether, or not, it is possible to retrieve robust near field velocity maps from stacking L-band interferograms, combining both single and dual polarization SAR data. In addition, we discuss whether a crustal velocity map can be used to complement GPS observations in an attempt to discriminate the present-day surface displacement of the Ganos fault (GF) across multiple segments. Finally, we characterize the spatial distribution of creep on shallow patches along multiple along-strike segments at shallow depths. Our results suggest the presence of fault segmentation along strike as well as creep on the shallow part of the fault (i.e. the existence of a shallow creeping patch) or the presence of a smoother section on the fault plane. Data imply a heterogeneous fault plane with more complex mechanics than previously thought. Because this study improves our knowledge of the mechanisms underlying the GF, our results have implications for local seismic hazard assessment. PMID:28961264

The 2016 Kaikōura earthquake: Simultaneous rupture of the subduction interface and overlying faults

NASA Astrophysics Data System (ADS)

Wang, Teng; Wei, Shengji; Shi, Xuhua; Qiu, Qiang; Li, Linlin; Peng, Dongju; Weldon, Ray J.; Barbot, Sylvain

2018-01-01

The distribution of slip during an earthquake and how it propagates among faults in the subduction system play a major role in seismic and tsunami hazards, yet they are poorly understood because offshore observations are often lacking. Here we derive the slip distribution and rupture evolution during the 2016 Mw 7.9 Kaikōura (New Zealand) earthquake that reconcile the surface rupture, space geodetic measurements, seismological and tsunami waveform records. We use twelve fault segments, with eleven in the crust and one on the megathrust interface, to model the geodetic data and match the major features of the complex surface ruptures. Our modeling result indicates that a large portion of the moment is distributed on the subduction interface, making a significant contribution to the far field surface deformation and teleseismic body waves. The inclusion of local strong motion and teleseismic waveform data in the joint inversion reveals a unilateral rupture towards northeast with a relatively low averaged rupture speed of ∼1.5 km/s. The first 30 s of the rupture took place on the crustal faults with oblique slip motion and jumped between fault segments that have large differences in strike and dip. The peak moment release occurred at ∼65 s, corresponding to simultaneous rupture of both plate interface and the overlying splay faults with rake angle changes progressively from thrust to strike-slip. The slip on the Papatea fault produced more than 2 m of offshore uplift, making a major contribution to the tsunami at the Kaikōura station, while the northeastern end of the rupture can explain the main features at the Wellington station. Our inversions and simulations illuminate complex up-dip rupture behavior that should be taken into consideration in both seismic and tsunami hazard assessment. The extreme complex rupture behavior also brings new challenges to the earthquake dynamic simulations and understanding the physics of earthquakes.

Geometry of the southern San Andreas fault and its implications for seismic hazard

NASA Astrophysics Data System (ADS)

Langenheim, V. E.; Dorsey, R. J.; Fuis, G. S.; Cooke, M. L.; Fattaruso, L.; Barak, S.

2015-12-01

The southern San Andreas fault (SSAF) provides rich opportunities for studying the geometry and connectivity of fault stepovers and intersections, including recently recognized NE tilting of the Salton block between the SSAF and San Jacinto fault (SJF) that likely results from slight obliquity of relative plate motion to the strike of the SSAF. Fault geometry and predictions of whether the SSAF will rupture through the restraining bend in San Gorgonio Pass (SGP) are controversial, with significant implications for seismic hazard. The evolution of faulting in SGP has led to various models of strain accommodation, including clockwise rotation of fault-bounded blocks east of the restraining bend, and generation of faults that siphon strike slip away from the restraining bend onto the SJF (also parallel to the SSAF). Complex deformation is not restricted to the upper crust but extends to mid- and lower-crustal depths according to magnetic data and ambient-noise surface-wave tomography. Initiation of the SJF ~1.2 Ma led to formation of the relatively intact Salton block, and end of extension on the West Salton detachment fault on the west side of Coachella Valley. Geologic and geomorphic data show asymmetry of the southern Santa Rosa Mountains, with a steep fault-bounded SW flank produced by active uplift, and gentler topographic gradients on the NE flank with tilted, inactive late Pleistocene fans that are incised by modern upper fan channels. Gravity data indicate the basin floor beneath Coachella Valley is also asymmetric, with a gently NE-dipping basin floor bound by a steep SSAF; seismic-reflection data suggest that NE tilting took place during Quaternary time. 3D numerical modeling predicts gentle NE dips in the Salton block that result from the slight clockwise orientation of relative motion across a NE-dipping SSAF. A NE dip of the SSAF, supported by various geophysical datasets, would reduce shaking in Coachella Valley compared to a vertical fault.

Multi-hazard risk assessment of coastal vulnerability from tropical cyclones - A GIS based approach for the Odisha coast.

PubMed

Sahoo, Bishnupriya; Bhaskaran, Prasad K

2018-01-15

The coastal region bordering the East coast of India is a thickly populated belt exposed to high risk and vulnerability from natural hazards such as tropical cyclones. Tropical cyclone frequencies that develop over the Bay of Bengal (average of 5-6 per year) region are much higher as compared to the Arabian Sea thereby posing a high risk factor associated with storm surge, inland inundation, wind gust, intense rainfall, etc. The Odisha State in the East coast of India experiences the highest number of cyclone strikes as compared to West Bengal, Andhra Pradesh, and Tamil Nadu. To express the destructive potential resulting from tropical cyclones the Power Dissipation Index (PDI) is a widely used metric globally. A recent study indicates that PDI for cyclones in the present decade have increased about six times as compared to the past. Hence there is a need to precisely ascertain the coastal vulnerability and risk factors associated with high intense cyclones expected in a changing climate. As such there are no comprehensive studies attempted so far on the determination of Coastal Vulnerability Index (CVI) for Odisha coast that is highly prone to cyclone strikes. With this motivation, the present study makes an attempt to investigate the physical, environmental, social, and economic impacts on coastal vulnerability associated with tropical cyclones for the Odisha coast. The study also investigates the futuristic projection of coastal vulnerability over this region expected in a changing climate scenario. Eight fair weather parameters along with storm surge height and onshore inundation were used to estimate the Physical Vulnerability Index (PVI). Thereafter, the PVI along with social, economic, and environmental vulnerability was used to determine the overall CVI using the GIS based approach. The authors believe that the comprehensive nature of this study is expected to benefit coastal zone management authorities. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intra-arc Seismicity: Geometry and Kinematic Constraints of Active Faulting along Northern Liquiñe-Ofqui and Andean Transverse Fault Systems [38º and 40ºS, Southern Andes

NASA Astrophysics Data System (ADS)

Sielfeld, G.; Lange, D.; Cembrano, J. M.

2017-12-01

Intra-arc crustal seismicity documents the schizosphere tectonic state along active magmatic arcs. At oblique-convergent margins, a significant portion of bulk transpressional deformation is accommodated in intra-arc regions, as a consequence of stress and strain partitioning. Simultaneously, crustal fluid migration mechanisms may be controlled by the geometry and kinematics of crustal high strain domains. In such domains shallow earthquakes have been associated with either margin-parallel strike-slip faults or to volcano-tectonic activity. However, very little is known on the nature and kinematics of Southern Andes intra-arc crustal seismicity and its relation with crustal faults. Here we present results of a passive seismicity study based on 16 months of data collected from 33 seismometers deployed along the intra-arc region of Southern Andes between 38˚S and 40˚S. This region is characterized by a long-lived interplay among margin-parallel strike-slip faults (Liquiñe-Ofqui Fault System, LOFS), second order Andean-transverse-faults (ATF), volcanism and hydrothermal activity. Seismic signals recorded by our network document small magnitude (0.2P and 2,796 S phase arrival times have been located with NonLinLoc. First arrival polarities and amplitude ratios of well-constrained events, were used for focal mechanism inversion. Local seismicity occurs at shallow levels down to depth of ca. 16 km, associated either with stratovolcanoes or to master, N10˚E, and subsidiary, NE to ENE, striking branches of the LOFS. Strike-slip focal mechanisms are consistent with the long-term kinematics documented by field structural-geology studies. Unexpected, well-defined NW-SE elongated clusters are also reported. In particular, a 72-hour-long, N60˚W-oriented seismicity swarm took place at Caburgua Lake area, describing a ca. 36x12x1km3 faulting crustal volume. Results imply a unique snapshot on shallow crustal tectonics, contributing to the understanding of faulting processes in volcanic arcs and ultimately, providing useful knowledge to improve the quality of hazard assessment communities emplaced in Southern Andes volcanic arc.

Structural control on volcanoes and magma paths from local- to orogen-scale: The central Andes case

NASA Astrophysics Data System (ADS)

Tibaldi, A.; Bonali, F. L.; Corazzato, C.

2017-03-01

Assessing the parameters that control the location and geometry of magma paths is of paramount importance for the comprehension of volcanic plumbing systems and geo-hazards. We analyse the distribution of 1518 monogenic and polygenic volcanoes of Miocene-Quaternary age of the Central Volcanic Zone of the Andes (Chile-Bolivia-Argentina), and reconstruct the magma paths at 315 edifices by analysing the morphostructural characteristics of craters and cones. Then we compare these data with outcropping dykes, tectonic structures and state of stress. Most magma paths trend N-S, NW-SE, and NE-SW, in decreasing order of frequency. The N-S and NW-SE paths coexist in the northern and southern part of the study area, whereas N-S paths dominate east of the Salar de Atacama. Outcropping dykes show the same trends. The regional Holocene stress state is given by an E-W greatest horizontal principal stress. N-S and NNE-SSW reverse faults and folds affect deposits of 4.8, 3.2 and 1.3 Ma BP, especially in the central and southern study areas. A few NW-SE left-lateral strike-slip faults are present in the interior of the volcanic arc, part of which belong to the Calama-Olacapato-El Toro fault. The volcanic chain is also affected by several N-S- and NW-SE-striking normal faults that offset Pliocene and Quaternary deposits. The results indicate different scenarios of magma-tectonic interaction, given by N-S normal and reverse faults and N-S fold hinges that guide volcano emplacement and magma paths. Magma paths are also guided by strike-slip and normal NW-SE faults, especially in the northern part of the study area. Zones with verticalized strata, with bedding striking NE-SW, also acted as preferential magma paths. These data suggest that at convergence zones with continental crust, shallow magma paths can be more sensitive to the presence and geometry of upper crustal weakness zones than to the regional state of stress.

Stress transfer to the Denali and other regional faults from the M 9.2 Alaska earthquake of 1964

USGS Publications Warehouse

Bufe, C.G.

2004-01-01

Stress transfer from the great 1964 Prince William Sound earthquake is modeled on the Denali fault, including the Denali-Totschunda fault segments that ruptured in 2002, and on other regional fault systems where M 7.5 and larger earthquakes have occurred since 1900. The results indicate that analysis of Coulomb stress transfer from the dominant earthquake in a region is a potentially powerful tool in assessing time-varying earthquake hazard. Modeled Coulomb stress increases on the northern Denali and Totschunda faults from the great 1964 earthquake coincide with zones that ruptured in the 2002 Denali fault earthquake, although stress on the Susitna Glacier thrust plane, where the 2002 event initiated, was decreased. A southeasterlytrending Coulomb stress transect along the right-lateral Totschunda-Fairweather-Queen Charlotte trend shows stress transfer from the 1964 event advancing slip on the Totschunda, Fairweather, and Queen Charlotte segments, including the southern Fairweather segment that ruptured in 1972. Stress transfer retarding right-lateral strike slip was observed from the southern part of the Totschunda fault to the northern end of the Fairweather fault (1958 rupture). This region encompasses a gap with shallow thrust faulting but with little evidence of strike-slip faulting connecting the segments to the northwest and southeast. Stress transfer toward failure was computed on the north-south trending right-lateral strike-slip faults in the Gulf of Alaska that ruptured in 1987 and 1988, with inhibitory stress changes at the northern end of the northernmost (1987) rupture. The northern Denali and Totschunda faults, including the zones that ruptured in the 2002 earthquakes, follow very closely (within 3%), for about 90??, an arc of a circle of radius 375 km. The center of this circle is within a few kilometers of the intersection at depth of the Patton Bay fault with the Alaskan megathrust. This inferred asperity edge may be the pole of counterclockwise rotation of the block south of the Denali fault. These observations suggest that the asperity and its recurrent rupture in great earthquakes as in 1964 may have influenced the tectonics of the region during the later stages of evolution of the Denali strike-slip fault system.

Orogen-scale uplift in the central Italian Apennines drives episodic behaviour of earthquake faults

PubMed Central

Cowie, P. A.; Phillips, R. J.; Roberts, G. P.; McCaffrey, K.; Zijerveld, L. J. J.; Gregory, L. C.; Faure Walker, J.; Wedmore, L. N. J.; Dunai, T. J.; Binnie, S. A.; Freeman, S. P. H. T.; Wilcken, K.; Shanks, R. P.; Huismans, R. S.; Papanikolaou, I.; Michetti, A. M.; Wilkinson, M.

2017-01-01

Many areas of the Earth’s crust deform by distributed extensional faulting and complex fault interactions are often observed. Geodetic data generally indicate a simpler picture of continuum deformation over decades but relating this behaviour to earthquake occurrence over centuries, given numerous potentially active faults, remains a global problem in hazard assessment. We address this challenge for an array of seismogenic faults in the central Italian Apennines, where crustal extension and devastating earthquakes occur in response to regional surface uplift. We constrain fault slip-rates since ~18 ka using variations in cosmogenic 36Cl measured on bedrock scarps, mapped using LiDAR and ground penetrating radar, and compare these rates to those inferred from geodesy. The 36Cl data reveal that individual faults typically accumulate meters of displacement relatively rapidly over several thousand years, separated by similar length time intervals when slip-rates are much lower, and activity shifts between faults across strike. Our rates agree with continuum deformation rates when averaged over long spatial or temporal scales (104 yr; 102 km) but over shorter timescales most of the deformation may be accommodated by <30% of the across-strike fault array. We attribute the shifts in activity to temporal variations in the mechanical work of faulting. PMID:28322311

Large-scale fault interactions at the termination of a subduction margin

NASA Astrophysics Data System (ADS)

Mouslopoulou, V.; Nicol, A., , Prof; Moreno, M.; Oncken, O.; Begg, J.; Kufner, S. K.

2017-12-01

Active subduction margins terminate against, and transfer their slip onto, plate-boundary transform faults. The manner in which plate motion is accommodated and partitioned across such kinematic transitions from thrust to strike-slip faulting over earthquake timescales, is poorly documented. The 2016 November 14th, Mw 7.8 Kaikoura Earthquake provides a rare snapshot of how seismic-slip may be accommodated at the tip of an active subduction margin. Analysis of uplift data collected using a range of techniques (field measurements, GPS, LiDAR) and published mapping coupled with 3D dislocation modelling indicates that earthquake-slip ruptured multiple faults with various orientations and slip mechanisms. Modelled and measured uplift patterns indicate that slip on the plate-interface was minor. Instead, a large offshore thrust fault, modelled to splay-off the plate-interface and to extend to the seafloor up to 15 km east of the South Island, appears to have released subduction-related strain and to have facilitated slip on numerous, strike-slip and oblique-slip faults on its hanging-wall. The Kaikoura earthquake suggests that these large splay-thrust faults provide a key mechanism in the transfer of plate motion at the termination of a subduction margin and represent an important seismic hazard.

Daily variation in natural disaster casualties: information flows, safety, and opportunity costs in tornado versus hurricane strikes.

PubMed

Zahran, Sammy; Tavani, Daniele; Weiler, Stephan

2013-07-01

Casualties from natural disasters may depend on the day of the week they strike. With data from the Spatial Hazard Events and Losses Database for the United States (SHELDUS), daily variation in hurricane and tornado casualties from 5,043 tornado and 2,455 hurricane time/place events is analyzed. Hurricane forecasts provide at-risk populations with considerable lead time. Such lead time allows strategic behavior in choosing protective measures under hurricane threat; opportunity costs in terms of lost income are higher during weekdays than during weekends. On the other hand, the lead time provided by tornadoes is near zero; hence tornados generate no opportunity costs. Tornado casualties are related to risk information flows, which are higher during workdays than during leisure periods, and are related to sheltering-in-place opportunities, which are better in permanent buildings like businesses and schools. Consistent with theoretical expectations, random effects negative binomial regression results indicate that tornado events occurring on the workdays of Monday through Thursday are significantly less lethal than tornados that occur on weekends. In direct contrast, and also consistent with theory, the expected count of hurricane casualties increases significantly with weekday occurrences. The policy implications of observed daily variation in tornado and hurricane events are considered. © 2012 Society for Risk Analysis.

Orogen-scale uplift in the central Italian Apennines drives episodic behaviour of earthquake faults.

PubMed

Cowie, P A; Phillips, R J; Roberts, G P; McCaffrey, K; Zijerveld, L J J; Gregory, L C; Faure Walker, J; Wedmore, L N J; Dunai, T J; Binnie, S A; Freeman, S P H T; Wilcken, K; Shanks, R P; Huismans, R S; Papanikolaou, I; Michetti, A M; Wilkinson, M

2017-03-21

Many areas of the Earth's crust deform by distributed extensional faulting and complex fault interactions are often observed. Geodetic data generally indicate a simpler picture of continuum deformation over decades but relating this behaviour to earthquake occurrence over centuries, given numerous potentially active faults, remains a global problem in hazard assessment. We address this challenge for an array of seismogenic faults in the central Italian Apennines, where crustal extension and devastating earthquakes occur in response to regional surface uplift. We constrain fault slip-rates since ~18 ka using variations in cosmogenic 36 Cl measured on bedrock scarps, mapped using LiDAR and ground penetrating radar, and compare these rates to those inferred from geodesy. The 36 Cl data reveal that individual faults typically accumulate meters of displacement relatively rapidly over several thousand years, separated by similar length time intervals when slip-rates are much lower, and activity shifts between faults across strike. Our rates agree with continuum deformation rates when averaged over long spatial or temporal scales (10 4  yr; 10 2  km) but over shorter timescales most of the deformation may be accommodated by <30% of the across-strike fault array. We attribute the shifts in activity to temporal variations in the mechanical work of faulting.

Numerical simulation of the 1976 Ms7.8 Tangshan Earthquake

NASA Astrophysics Data System (ADS)

Li, Zhengbo; Chen, Xiaofei

2017-04-01

An Ms 7.8 earthquake happened in Tangshan in 1976, causing more than 240000 people death and almost destroying the whole city. Numerous studies indicated that the surface rupture zone extends 8 to 11 km in the south of Tangshan City. The fault system is composed with more than ten NE-trending right-lateral strike-slip left-stepping echelon faults, with a general strike direction of N30°E. However, recent scholars proposed that the surface ruptures appeared in a larger area. To simulate the rupture process closer to the real situation, the curvilinear grid finite difference method presented by Zhang et al. (2006, 2014) which can handle the free surface and the complex geometry were implemented to investigate the dynamic rupture and ground motion of Tangshan earthquake. With the data from field survey, seismic section, borehole and trenching results given by different studies, several fault geometry models were established. The intensity, the seismic waveform and the displacement resulted from the simulation of different models were compared with the observed data. The comparison of these models shows details of the rupture process of the Tangshan earthquake and implies super-shear may occur during the rupture, which is important for better understanding of this complicated rupture process and seismic hazard distributions of this earthquake.

Maternal employment in Scandinavia: a comparison of the after-birth employment activity of Norwegian and Swedish women.

PubMed

Ronsen, M; Sundstrom, M

1996-01-01

"A striking characteristic of recent Western labour market trends is the rise in employment among mothers of very young children. So far, few studies have analysed the impact of public policies on employment rates of young mothers. In this study we address this issue by comparing two similar countries, Norway and Sweden, which have the same set of policies with slight variations, using data sets with similar designs. We analyse rates of re-entry into paid work after first birth for mothers in 1968-88 by means of hazard regression. One important finding is that the right to paid maternity leave with job security greatly speeds up the return to work." excerpt

Drought Monitoring with VegDRI

USGS Publications Warehouse

Brown, Jesslyn F.

2010-01-01

Drought strikes somewhere in the United States every year, turning green landscapes brown as precipitation falls below normal levels and water supplies dwindle. Drought is typically a temporary climatic aberration, but it is also an insidious natural hazard. It might last for weeks, months, or years and may have many negative effects. Drought can threaten crops, livestock, and livelihoods, stress wildlife and habitats, and increase wildfire risks and threats to human health. Drought conditions can vary tremendously from place to place and week to week. Accurate drought monitoring is essential to understand a drought's progression and potential effects, and to provide information necessary to support drought mitigation decisions. It is also crucial in light of climate change where droughts could become more frequent, severe, and persistent.

Map and Database of Probable and Possible Quaternary Faults in Afghanistan

USGS Publications Warehouse

Ruleman, C.A.; Crone, A.J.; Machette, M.N.; Haller, K.M.; Rukstales, K.S.

2007-01-01

The U.S. Geological Survey (USGS) with support from the U.S. Agency for International Development (USAID) mission in Afghanistan, has prepared a digital map showing the distribution of probable and suspected Quaternary faults in Afghanistan. This map is a key component of a broader effort to assess and map the country's seismic hazards. Our analyses of remote-sensing imagery reveal a complex array of tectonic features that we interpret to be probable and possible active faults within the country and in the surrounding border region. In our compilation, we have mapped previously recognized active faults in greater detail, and have categorized individual features based on their geomorphic expression. We assigned mapped features to eight newly defined domains, each of which contains features that appear to have similar styles of deformation. The styles of deformation associated with each domain provide insight into the kinematics of the modern tectonism, and define a tectonic framework that helps constrain deformational models of the Alpine-Himalayan orogenic belt. The modern fault movements, deformation, and earthquakes in Afghanistan are driven by the collision between the northward-moving Indian subcontinent and Eurasia. The patterns of probable and possible Quaternary faults generally show that much of the modern tectonic activity is related to transfer of plate-boundary deformation across the country. The left-lateral, strike-slip Chaman fault in southeastern Afghanistan probably has the highest slip rate of any fault in the country; to the north, this slip is distributed onto several fault systems. At the southern margin of the Kabul block, the style of faulting changes from mainly strike-slip motion associated with the boundary between the Indian and Eurasian plates, to transpressional and transtensional faulting. North and northeast of the Kabul block, we recognized a complex pattern of potentially active strike-slip, thrust, and normal faults that form a conjugate shear system in a transpressional region of the Trans-Himalayan orogenic belt. The general patterns and orientations of faults and the styles of deformation that we interpret from the imagery are consistent with the styles of faulting determined from focal mechanisms of historical earthquakes. Northwest-trending strike-slip fault zones are cut and displaced by younger, southeast-verging thrust faults; these relations define the interaction between northwest-southeast-oriented contraction and northwest-directed extrusion in the western Himalaya, Pamir, and Hindu Kush regions. Transpression extends into north-central Afghanistan where north-verging contraction along the east-west-trending Alburz-Marmul fault system interacts with northwest-trending strike-slip faults. Pressure ridges related to thrust faulting and extensional basins bounded by normal faults are located at major stepovers in these northwest-trending strike-slip systems. In contrast, young faulting in central and western Afghanistan indicates that the deformation is dominated by extension where strike-slip fault zones transition into regions of normal faults. In addition to these initial observations, our digital map and database provide a foundation that can be expanded, complemented, and modified as future investigations provide more detailed information about the location, characteristics, and history of movement on Quaternary faults in Afghanistan.

Fluor Daniel Hanford implementation plan for DOE Order 5480.28, Natural phenomena hazards mitigation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conrads, T.J.

1997-09-12

Natural phenomena hazards (NPH) are unexpected acts of nature that pose a threat or danger to workers, the public, or the environment. Earthquakes, extreme winds (hurricane and tornado), snow, flooding, volcanic ashfall, and lightning strikes are examples of NPH that could occur at the Hanford Site. U.S. Department of Energy (DOE) policy requires facilities to be designed, constructed, and operated in a manner that protects workers, the public, and the environment from hazards caused by natural phenomena. DOE Order 5480.28, Natural Phenomena Hazards Mitigation, includes rigorous new natural phenomena criteria for the design of new DOE facilities, as well asmore » for the evaluation and, if necessary, upgrade of existing DOE facilities. The Order was transmitted to Westinghouse Hanford Company in 1993 for compliance and is also identified in the Project Hanford Management Contract, Section J, Appendix C. Criteria and requirements of DOE Order 5480.28 are included in five standards, the last of which, DOE-STD-1023, was released in fiscal year 1996. Because the Order was released before all of its required standards were released, enforcement of the Order was waived pending release of the last standard and determination of an in-force date by DOE Richland Operations Office (DOE-RL). Agreement also was reached between the Management and Operations Contractor and DOE-RL that the Order would become enforceable for new structures, systems, and components (SSCS) 60 days following issue of a new order-based design criteria in HNF-PRO-97, Engineering Design and Evaluation. The order also requires that commitments addressing existing SSCs be included in an implementation plan that is to be issued 1 year following the release of the last standard. Subsequently, WHC-SP-1175, Westinghouse Hanford Company Implementation Plan for DOE Order 5480.28, Natural Phenomena Hazards Mitigation, Rev. 0, was issued in November 1996, and this document, HNF-SP-1175, Fluor Daniel Hanford Implementation Plan for DOE Order 5480.28, Natural Phenomena Hazards Mitigation, is Rev. 1 of that plan.« less

Birds and Aircraft on Midway Islands, 1959-63 Investigations

USGS Publications Warehouse

Robbins, C.S.

1966-01-01

At Midway Naval Station, 1.100 miles west-northwest of Honolulu, military aircraft collide with flying albatrosses at the rate of about 300 to 400 per year. One aircraft out of every five that hits an albatross on takeoff either aborts (stops before it is airborne), or dumps fuel and returns for appraisal of damage. About 70,000 pairs of Laysan albatrosses and 7,000 pairs of blackfooted albatrosses nest at Midway in any given year. The population is declining. Two-thirds or more of the birds of breeding age nest each year. The minimum breeding age recorded is 5 years (each species), but many individuals do not nest until at least 7 years of age. Young birds begin to return to Midway at 3 years of age and are found more frequently as breeding age approaches. They come ashore more frequently in March and April (the high bird strike months) than in midwinter. Even in midwinter the number of 'walkers' (birds not on nests) may comprise more than 40 percent of the albatrosses present on Sand Island, Midway. Maximum longevity of the Laysan albatross is believed to exceed 40 years; 6 out of 99 birds banded as breeding adults (7+ years old) were still alive 24 years after banding. Control methods tested experimentally include disturbance, gunfire, other sounds, radar beams, smoke, odors, destruction of nests, eggs, chicks, and adults, moving of birds, eggs, and chicks, erection of obstacles to flight, and habitat management. Habitat management (leveling and hardsurfacing of shoulders of runways) has been the most effective. Albatrosses were counted over the runways at 10 locations in 1957, 1958, and 1960 to determine the effects of wind direction, wind speed, and topography on the numbers of flying birds. Birds were most concentrated in areas where rising air currents were created as winds blew against dunes or tall trees. Soaring and strike rate both increased with greater wind speeds. There was a highly significant correlation between strike frequency and wind direction. Soaring and strike rate were greatest over runway 6-24 when winds were from a northerly quadrant, and greatest over runway 15-33 when winds were east to southeast. Counts (nearly 7,000 observations) before and after the leveling of dunes along part of the south side of the principal runway, 6-24, showed a 61 percent decrease in soaring over the principal runway as compared with a 4 percent increase over runway 15-33 where no major habitat management had been done. Studies of population dynamics of Laysan and black-footed albatrosses in 4 study plots (totaling 14 1/2 acres) are yielding information on nesting density, changes in nesting population from year to year, frequency of nesting of individual birds, closeness of return, reproductive success, rate of nest loss, age at which young birds begin nesting, age composition of the population, and life expectancy of adults. Recommendations are made for reducing the bird hazard and for protecting birds that are not involved in the hazard.

Preliminary geologic map of the San Guillermo Mountain Quadrangle, Ventura County, California

USGS Publications Warehouse

Minor, S.A.

1999-01-01

New 1:24,000-scale geologic mapping in the Cuyama 30' x 60' quadrangle, in support of the USGS Southern California Areal Mapping Project (SCAMP), is contributing to a more complete understanding of the stratigraphy, structure, and tectonic evolution of the complex junction area between the NW-striking Coast Ranges and EW-striking western Transverse Ranges. The 1:24,000-scale geologic map of the San Guillermo Mountain quadrangle is one of six contiguous 7 1/2' quadrangle geologic maps in the eastern part of the Cuyama map area being compiled for a more detailed portrayal and reevaluation of geologic structures and rock units shown on previous geologic maps of the area (e.g., Dibblee, 1979). The following observations and interpretations are based on the new San Guillermo Mountain geologic compilation: (1) The new geologic mapping in the northern part of the San Guillermo Mountain quadrangle allows for reinterpretation of fault architecture that bears on potential seismic hazards of the region. Previous mapping had depicted the eastern Big Pine fault (BPF) as a northeast-striking, sinistral strike-slip fault that extends for 30 km northeast of the Cuyama River to its intersection with the San Andreas fault (SAF). In contrast the new mapping indicates that the eastern BPF is a thrust fault that curves from a northeast strike to an east strike, where it is continuous with the San Guillermo thrust fault, and dies out further east about 15 km south of the SAF. This redefined segment of the BPF is a south-dipping, north-directed thrust, with dominantly dip slip components (rakes > 60 deg.), that places Middle Eocene marine rocks (Juncal and Matilija Formations) over Miocene through Pliocene(?) nonmarine rocks (Caliente, Quatal, and Morales Formations). Although a broad northeast-striking fault zone, exhibiting predominantly sinistral components of slip (rakes < 45 deg.), extends to the SAF as previously mapped, the fault zone does not connect to the southwest with the BPF but instead curves into a southwest-directed thrust fault system a short distance north of the BPF. Oligocene to Pliocene(?) nonmarine sedimentary and volcanic rocks of the Plush Ranch, Caliente, and Morales(?) Formations are folded on both sides of this fault zone (informally named the Lockwood Valley fault zone [LVFZ] on the map). South-southeast of the LVFZ overturned folds have southward vergence. Several moderate-displacement (< 50 m), mainly northwest-dipping thrust and reverse faults, exhibiting mostly sinistral-oblique slip, flank and strike parallel to the overturned folds. The fold vergence and thrust direction associated with the LVFZ is opposite to that of the redefined BPF, providing further evidence that the two faults are distinct structures. These revised fault interpretations bring into question earlier estimates of net sinistral strike-slip displacement of as much as 13 km along the originally defined eastern BPF, which assumed structural connection with the LVFZ. Also, despite sparse evidence for repeated Quaternary movement on the LVFZ (e.g., Dibblee, 1982), the potential for a large earthquake involving coseismic slip on both the LVFZ and the central BPF to the southwest may not be as great as once believed. (2) Several generations of Pleistocene and younger dissected alluvial terrace and fan deposits sit at various levels above modern stream channels throughout the quadrangle. These deposits give testimony to the recent uplift and related fault deformation that has occurred in the area. (3) A vast terrane of Eocene marine sedimentary rocks (Juncal and Matilija Formations and Cozy Dell Shale) exposed south of the Big Pine fault forms the southern two-thirds of the San Guillermo Mountain quadrangle. Benthic foraminifers collected from various shale intervals within the Juncal Formation indicate a Middle Eocene age (Ulatisian) for the entire formation (K. McDougall, unpub. data, 1998) and deposition at paleodepths as great as 2,000 m (i.e., lowe

Model for breast cancer survival: relative prognostic roles of axillary nodal status, TNM stage, estrogen receptor concentration, and tumor necrosis.

PubMed

Shek, L L; Godolphin, W

1988-10-01

The independent prognostic effects of certain clinical and pathological variables measured at the time of primary diagnosis were assessed with Cox multivariate regression analysis. The 859 patients with primary breast cancer, on which the proportional hazards model was based, had a median follow-up of 60 months. Axillary nodal status (categorized as N0, N1-3 or N4+) was the most significant and independent factor in overall survival, but inclusion of TNM stage, estrogen receptor (ER) concentration and tumor necrosis significantly improved survival predictions. Predictions made with the model showed striking subset survival differences within stage: 5-year survival from 36% (N4+, loge[ER] = 0, marked necrosis) to 96% (N0, loge[ER] = 6, no necrosis) in TNM I, and from 0 to 70% for the same categories in TNM IV. Results of the model were used to classify patients into four distinct risk groups according to a derived hazard index. An 8-fold variation in survival was seen with the highest (greater than 3) to lowest index values (less than 1). Each hazard index level included patients with varied combinations of the above factors, but could be considered to denote the same degree of risk of breast cancer mortality. A model with ER concentration, nodal status, and tumor necrosis was found to best predict survival after disease recurrence in 369 patients, thus confirming the enduring biological significance of these factors.

Mitigating flood exposure: Reducing disaster risk and trauma signature.

PubMed

Shultz, James M; McLean, Andrew; Herberman Mash, Holly B; Rosen, Alexa; Kelly, Fiona; Solo-Gabriele, Helena M; Youngs, Georgia A; Jensen, Jessica; Bernal, Oscar; Neria, Yuval

2013-01-01

Introduction. In 2011, following heavy winter snowfall, two cities bordering two rivers in North Dakota, USA faced major flood threats. Flooding was foreseeable and predictable although the extent of risk was uncertain. One community, Fargo, situated in a shallow river basin, successfully mitigated and prevented flooding. For the other community, Minot, located in a deep river valley, prevention was not possible and downtown businesses and one-quarter of the homes were inundated, in the city's worst flood on record. We aimed at contrasting the respective hazards, vulnerabilities, stressors, psychological risk factors, psychosocial consequences, and disaster risk reduction strategies under conditions where flood prevention was, and was not, possible. Methods . We applied the "trauma signature analysis" (TSIG) approach to compare the hazard profiles, identify salient disaster stressors, document the key components of disaster risk reduction response, and examine indicators of community resilience. Results . Two demographically-comparable communities, Fargo and Minot, faced challenging river flood threats and exhibited effective coordination across community sectors. We examined the implementation of disaster risk reduction strategies in situations where coordinated citizen action was able to prevent disaster impact (hazard avoidance) compared to the more common scenario when unpreventable disaster strikes, causing destruction, harm, and distress. Across a range of indicators, it is clear that successful mitigation diminishes both physical and psychological impact, thereby reducing the trauma signature of the event. Conclusion . In contrast to experience of historic flooding in Minot, the city of Fargo succeeded in reducing the trauma signature by way of reducing risk through mitigation.

Mitigating flood exposure

PubMed Central

Shultz, James M; McLean, Andrew; Herberman Mash, Holly B; Rosen, Alexa; Kelly, Fiona; Solo-Gabriele, Helena M; Youngs Jr, Georgia A; Jensen, Jessica; Bernal, Oscar; Neria, Yuval

2013-01-01

Introduction. In 2011, following heavy winter snowfall, two cities bordering two rivers in North Dakota, USA faced major flood threats. Flooding was foreseeable and predictable although the extent of risk was uncertain. One community, Fargo, situated in a shallow river basin, successfully mitigated and prevented flooding. For the other community, Minot, located in a deep river valley, prevention was not possible and downtown businesses and one-quarter of the homes were inundated, in the city’s worst flood on record. We aimed at contrasting the respective hazards, vulnerabilities, stressors, psychological risk factors, psychosocial consequences, and disaster risk reduction strategies under conditions where flood prevention was, and was not, possible. Methods. We applied the “trauma signature analysis” (TSIG) approach to compare the hazard profiles, identify salient disaster stressors, document the key components of disaster risk reduction response, and examine indicators of community resilience. Results. Two demographically-comparable communities, Fargo and Minot, faced challenging river flood threats and exhibited effective coordination across community sectors. We examined the implementation of disaster risk reduction strategies in situations where coordinated citizen action was able to prevent disaster impact (hazard avoidance) compared to the more common scenario when unpreventable disaster strikes, causing destruction, harm, and distress. Across a range of indicators, it is clear that successful mitigation diminishes both physical and psychological impact, thereby reducing the trauma signature of the event. Conclusion. In contrast to experience of historic flooding in Minot, the city of Fargo succeeded in reducing the trauma signature by way of reducing risk through mitigation. PMID:28228985

High-resolution seismic-reflection data offshore of Dana Point, southern California borderland

USGS Publications Warehouse

Sliter, Ray W.; Ryan, Holly F.; Triezenberg, Peter J.

2010-01-01

The U.S. Geological Survey collected high-resolution shallow seismic-reflection profiles in September 2006 in the offshore area between Dana Point and San Mateo Point in southern Orange and northern San Diego Counties, California. Reflection profiles were located to image folds and reverse faults associated with the San Mateo fault zone and high-angle strike-slip faults near the shelf break (the Newport-Inglewood fault zone) and at the base of the slope. Interpretations of these data were used to update the USGS Quaternary fault database and in shaking hazard models for the State of California developed by the Working Group for California Earthquake Probabilities. This cruise was funded by the U.S. Geological Survey Coastal and Marine Catastrophic Hazards project. Seismic-reflection data were acquired aboard the R/V Sea Explorer, which is operated by the Ocean Institute at Dana Point. A SIG ELC820 minisparker seismic source and a SIG single-channel streamer were used. More than 420 km of seismic-reflection data were collected. This report includes maps of the seismic-survey sections, linked to Google Earth? software, and digital data files showing images of each transect in SEG-Y, JPEG, and TIFF formats.

On the political economy of risk: farmworkers, pesticides, and dollars.

PubMed

Strigini, P

1982-01-01

The rapid industrialization of world agriculture has been one of the most eventful social and economic transformations taking place in the second half of the 20th century. Today two agricultures coexist in most countries: capital-intensive agri-business and labor-intensive subsistence farming. In the U.S., the former exploits largely nonwhite immigrant labor and the latter female unpaid labor, surviving as a "second job.' The striking increase of production in industrial agriculture has been accompanied by uneven and irrational development and by a tragic upsurge of mechanical accidents and chemical hazards. Current pesticide use poses a threat to workers and their families, the general public, the environment, and future generations. Acute risks begin to be known largely through farmworkers' exposure, while chronic risks are often inferred from experimental studies but generally are disregarded. Because of industry's historic neglect of health and environmental hazards, regulation has evolved under pressure from workers and citizens. Regulation is at present the best tool available to shape technological development according to society's needs and goals. Its basic requirements are information, reorientation of public resources, and democratic control. A major obstacle to its implementation is the inequitable social distribution of risks and benefits, within and among nations.

Design of intelligent proximity detection zones to prevent striking and pinning fatalities around continuous mining machines.

PubMed

Bissert, P T; Carr, J L; DuCarme, J P; Smith, A K

2016-01-01

The continuous mining machine is a key piece of equipment used in underground coal mining operations. Over the past several decades these machines have been involved in a number of mine worker fatalities. Proximity detection systems have been developed to avert hazards associated with operating continuous mining machines. Incorporating intelligent design into proximity detection systems allows workers greater freedom to position themselves to see visual cues or avoid other hazards such as haulage equipment or unsupported roof or ribs. However, intelligent systems must be as safe as conventional proximity detection systems. An evaluation of the 39 fatal accidents for which the Mine Safety and Health Administration has published fatality investigation reports was conducted to determine whether the accident may have been prevented by conventional or intelligent proximity. Multiple zone configurations for the intelligent systems were studied to determine how system performance might be affected by the zone configuration. Researchers found that 32 of the 39 fatalities, or 82 percent, may have been prevented by both conventional and intelligent proximity systems. These results indicate that, by properly configuring the zones of an intelligent proximity detection system, equivalent protection to a conventional system is possible.

Oklahoma experiences largest earthquake during ongoing regional wastewater injection hazard mitigation efforts

USGS Publications Warehouse

Yeck, William; Hayes, Gavin; McNamara, Daniel E.; Rubinstein, Justin L.; Barnhart, William; Earle, Paul; Benz, Harley M.

2017-01-01

The 3 September 2016, Mw 5.8 Pawnee earthquake was the largest recorded earthquake in the state of Oklahoma. Seismic and geodetic observations of the Pawnee sequence, including precise hypocenter locations and moment tensor modeling, shows that the Pawnee earthquake occurred on a previously unknown left-lateral strike-slip basement fault that intersects the mapped right-lateral Labette fault zone. The Pawnee earthquake is part of an unprecedented increase in the earthquake rate in Oklahoma that is largely considered the result of the deep injection of waste fluids from oil and gas production. If this is, indeed, the case for the M5.8 Pawnee earthquake, then this would be the largest event to have been induced by fluid injection. Since 2015, Oklahoma has undergone wide-scale mitigation efforts primarily aimed at reducing injection volumes. Thus far in 2016, the rate of M3 and greater earthquakes has decreased as compared to 2015, while the cumulative moment—or energy released from earthquakes—has increased. This highlights the difficulty in earthquake hazard mitigation efforts given the poorly understood long-term diffusive effects of wastewater injection and their connection to seismicity.

Fields of rice: health hazards for women and unborn children.

PubMed

Batliwala, S

1988-01-01

A death information study, to determine why the infant mortality rate failed to fall below 75/1000, was begun in January 1982, after 9 years of accomplishments by the rural health research project in Raigad district of coastal Maharashtra. All data were collected by 27 female rural health workers, some of whom were illiterate but received help from villagers. Death records included name, sex, age, date and time of death, and cause of death or symptoms before death. In the 0-6 age group, 64% of the deaths were girls. 80% of the dead children were infant deaths, and of these, 75% were neonatal, suggesting the influence of prenatal, obstetric and postnatal factors and maternal nutrition. The majority were related to premature and low birth weight babies. Another striking observation was that 40% of all infant deaths occurred in July-October, and 50% of these were stillbirths and premature births. July and August are the months when all women (and no men) work transplanting rice seedlings. This work is done by bending or squatting from dawn to dusk. Thus, rice culture must be considered an occupational hazard for women in late pregnancy.

Interpretations on the Geologic Setting of Yogyakarta Earthquakes 2006 (Central Java, Indonesia) Based on Integration of Aftershock Monitoring and Existing Geologic, Geophysical and Remote Sensing Data

NASA Astrophysics Data System (ADS)

Setijadji, L. D.; Watanabe, K.; Fukuoka, K.; Ehara, S.; Setiadji, Y.; Rahardjo, W.; Susilo, A.; Barianto, D. H.; Harijoko, A.; Sudarno, I.; Pramumijoyo, S.; Hendrayana, H.; Akmalludin, A.; Nishijima, J.; Itaya, T.

2007-05-01

The unprecedented 26 May 2006 Yogyakarta earthquake (central Java, Indonesia) that took victims of 5,700 lives was generally accepted to have a depth of about 10 km and moment magnitude of 6.4. However, the definition of location of active fault is still under debate as the epicenter of mainshock was reported quite differently by several institutions. Many researchers believe that the Opak fault which is located at the eastern boundary of Yogyakarta low-land area (or Yogyakarta Basin) and the high-land region of Southern Mountains was the source of year 2006 earthquakes. However, our result of aftershocks observation suggests that the ruptured zone was not located along the Opak fault but from an unknown fault located about 10 km to the east from it and within the Southern Mountains domain. Unfortunately, surface geologic manifestations are scarce as this area is now largely covered by limestone. Therefore the suspected active fault system must be studied through interpretations of the subsurface geology and evaluation of the Cenozoic geo-history of the region utilizing existing geologic, geophysical and remote sensing data. This work suggests that the Yogyakarta Basin is a volcano-tectonic depression formed gradually since the early Tertiary period (Oligo-Miocene or older). Geological and geophysical evidence suggest that structural trends changed from the Oligocene NE-SW towards the Oligo-Miocene NNE-SSW and the Plio-Pleistocene NW-SE and E-W directions. The ruptured "X" fault during the Yogyakarta earthquakes 2006 is likely to be a NNE-SSW trending fault which is parallel to the Opak fault and both were firstly active in the Oligo-Miocene as sinistral strike-slip faults. However, while the Opak fault had changed into a normal faulting after the Pliocene, the evidence from Kali Ngalang and Kali Widoro suggests that the "X" fault system was still reactivated as a strike-slip one during the Plio-Pleistocene orogeny. As this new interpretation of active fault causes spatial discrepancy between locations of earthquakes epicenters and highly damaged regions, other geo-engineering factors must be considerably important in determining the final scale of seismic hazards. The most vulnerable areas for seismic hazards are those located nearest to the ruptured fault and are underlain by thick Quaternary unconsolidated deposits. In case of regions along the fault line, seismic hazards seem to reach more distance region, such as the case of Gantiwarno region, as the seismic waves can travel more easily along the fault line.

Effect of the Road Environment on Road Safety in Poland

NASA Astrophysics Data System (ADS)

Budzynski, Marcin; Jamroz, Kazimierz; Antoniuk, Marcin

2017-10-01

Run-off-road accidents tend to be very severe because when a vehicle leaves the road, it will often crash into a solid obstacle (tree, pole, supports, front wall of a culvert, barrier). A statistical analysis of the data shows that Poland’s main roadside hazard is trees and the severity of vehicles striking a tree in a run-off-road crash. The risks are particularly high in north-west Poland with many of the roads lined up with trees. Because of the existing rural road cross-sections, i.e. having trees directly on road edge followed immediately by drainage ditches, vulnerable road users are prevented from using shoulders and made to use the roadway. With no legal definition of the road safety zone in Polish regulations, attempts to remove roadside trees lead to major conflicts with environmental stakeholders. This is why a compromise should be sought between the safety of road users and protection of the natural environment and the aesthetics of the road experience. Rather than just cut the trees, other road safety measures should be used where possible to treat the hazardous spots by securing trees and obstacles and through speed management. Accidents that are directly related to the road environment fall into the following categories: hitting a tree, hitting a barrier, hitting a utility pole or sign, vehicle rollover on the shoulder, vehicle rollover on slopes or in ditch. The main consequence of a roadside hazard is not the likelihood of an accident itself but of its severity. Poland’s roadside accident severity is primarily the result of poor design or operation of road infrastructure. This comes as a consequence of a lack of regulations or poorly defined regulations and failure to comply with road safety standards. The new analytical model was designed as a combination of the different factors and one that will serve as a comprehensive model. It was assumed that it will describe the effect of the roadside on the number of accidents and their consequences. The design of the model was based on recommendations from analysing other models. The assumptions were the following: the model will be used to calculate risk factors and accident severity, the indicators will depend on number of vehicle kilometres travelled or traffic volumes, analyses will be based on accident data: striking a tree, hitting a barrier, hitting a utility pole or sign. Additional data will include roadside information and casualty density measures will be used - killed and injured.

Foot-strike pattern and performance in a marathon

PubMed Central

Kasmer, Mark E.; Liu, Xue-cheng; Roberts, Kyle G.; Valadao, Jason M.

2016-01-01

Purpose To: 1) determine prevalence of heel-strike in a mid-size city marathon, 2) determine if there is an association between foot-strike classification and race performance, and 3) determine if there is an association between foot-strike classification and gender. Methods Foot-strike classification (fore-foot strike, mid-foot strike, heel strike, or split-strike), gender, and rank (position in race) were recorded at the 8.1 kilometer (km) mark for 2,112 runners at the 2011 Milwaukee Lakefront Marathon. Results 1,991 runners were classified by foot-strike pattern, revealing a heel-strike prevalence of 93.67% (n=1,865). A significant difference between foot-strike classification and performance was found using a Kruskal-Wallis test (p < 0.0001), with more elite performers being less likely to heel-strike. No significant difference between foot-strike classification and gender was found using a Fisher’s exact test. Additionally, subgroup analysis of the 126 non-heel strikers found no significant difference between shoe wear and performance using a Kruskal-Wallis test. Conclusions The high prevalence of heel-striking observed in this study reflects the foot-strike pattern of the majority of mid- to long-distance runners and more importantly, may predict their injury profile based on the biomechanics of a heel strike running pattern. This knowledge can aid the clinician in the appropriate diagnosis, management, and training modifications of the injured runner. PMID:23006790

Strike Manual: Related to Potential School Employee Strike Action.

ERIC Educational Resources Information Center

Loftus, Richard J., Jr., Ed.; And Others

Strikes and threats of strikes have become one of the realities of public education. School districts must be prepared to deal with strikes and the problems that they present. This manual is designed to provide a brief overview of the law relating to public employee strikes and to assist districts in adopting their own strike plans. It offers…

A simulated lightning effects test facility for testing live and inert missiles and components

NASA Technical Reports Server (NTRS)

Craven, Jeffery D.; Knaur, James A.; Moore, Truman W., Jr.; Shumpert, Thomas H.

1991-01-01

Details of a simulated lightning effects test facility for testing live and inert missiles, motors, and explosive components are described. The test facility is designed to simulate the high current, continuing current, and high rate-of-rise current components of an idealized direct strike lightning waveform. The Lightning Test Facility was in operation since May, 1988, and consists of: 3 separate capacitor banks used to produce the lightning test components; a permanently fixed large steel safety cage for retaining the item under test (should it be ignited during testing); an earth covered bunker housing the control/equipment room; a charge/discharge building containing the charging/discharging switching; a remotely located blockhouse from which the test personnel control hazardous testing; and interconnecting cables.

Improving work conditions through strike: Examination of nurses' attitudes through perceptions of two physician strikes in Israel.

PubMed

Gafni-Lachter, Liat; Admi, Hanna; Eilon, Yael; Lachter, Jesse

2017-01-01

Strikes are means to influence policies related to working conditions, yet raise ethical dilemmas for healthcare workers. Nurse strikes have become more prominent around the world. To assess the change in Israeli nurses' attitudes towards strikes in light of two physician strikes that have preceded a nursing strike. An anonymous survey was administered once in 2000 (N = 106) and again in 2011 (n = 175) following 110 days of a physician strike, to assess nurses' attitudes towards the strike and resulting ethical issues. A statistically significant change (p < 0.05) between administrations revealed that in 2011 more nurses identified striking as a legitimate mechanism, would strike under the same circumstances, and felt that collaboration with physicians persisted despite the strike. Additionally, an increasing number of nurses said that the suffering of patients due to the strike is somewhat or entirely justified, although they were faced with a difficult dilemma of loyalty to physician colleagues vs. Nurses reported finding ways to mitigate the suffering of patients resulting from the strike. While patient-centered care remains nurses' first and foremost priority, findings indicate an increasing support of collective bargaining and strike to promote working conditions related to professional and public health agendas.

Studies of Fault Interactions and Regional Seismicity Using Numerical Simulations

NASA Astrophysics Data System (ADS)

Yikilmaz, Mehmet Burak

Numerical simulations are routinely used for weather and climate forecasting. It is desirable to simulate regional seismicity for seismic hazard analysis. One such simulation tool is the Virtual California earthquake simulator. We have used Virtual California (VC) to study various aspects of fault interaction and analyzed the statistics of earthquake recurrence times and magnitudes generated synthetically. The first chapter of this dissertation investigates the behavior of seismology simulations using three relatively simple models involving a straight strike-slip fault. We show that a series of historical earthquakes observed along the Nankai Trough in Japan exhibit similar patterns to those obtained in our model II. In the second chapter we utilize Virtual California to study regional seismicity in northern California. We generate synthetic catalogs of seismicity using a composite simulation. We use these catalogs to analyze frequency-magnitude and recurrence interval statistics on both a regional and fault specific level and compare our modeled rates of seismicity and spatial variability with observations. The final chapter explores the jump distance for a propagating rupture over a stepping strike-slip fault. Our study indicates that between 2.5 and 5.5 km of the separation distance, the percentage of events that jump from one fault to the next decreases significantly. We find that these step-over distance values are in good agreement with geologically observed values.

Active faulting in apparently stable peninsular India: Rift inversion and a Holocene-age great earthquake on the Tapti Fault

NASA Astrophysics Data System (ADS)

Copley, Alex; Mitra, Supriyo; Sloan, R. Alastair; Gaonkar, Sharad; Reynolds, Kirsty

2014-08-01

We present observations of active faulting within peninsular India, far from the surrounding plate boundaries. Offset alluvial fan surfaces indicate one or more magnitude 7.6-8.4 thrust-faulting earthquakes on the Tapti Fault (Maharashtra, western India) during the Holocene. The high ratio of fault displacement to length on the alluvial fan offsets implies high stress-drop faulting, as has been observed elsewhere in the peninsula. The along-strike extent of the fan offsets is similar to the thickness of the seismogenic layer, suggesting a roughly equidimensional fault rupture. The subsiding footwall of the fault is likely to have been responsible for altering the continental-scale drainage pattern in central India and creating the large west flowing catchment of the Tapti river. A preexisting sedimentary basin in the uplifting hanging wall implies that the Tapti Fault was active as a normal fault during the Mesozoic and has been reactivated as a thrust, highlighting the role of preexisting structures in determining the rheology and deformation of the lithosphere. The slip sense of faults and earthquakes in India suggests that deformation south of the Ganges foreland basin is driven by the compressive force transmitted between India and the Tibetan Plateau. The along-strike continuation of faulting to the east of the Holocene ruptures we have studied represents a significant seismic hazard in central India.

Photon Luminescence of the Moon

NASA Technical Reports Server (NTRS)

Wilson, T.L.; Lee, K.T.

2009-01-01

Luminescence is typically described as light emitted by objects at low temperatures, induced by chemical reactions, electrical energy, atomic interactions, or acoustical and mechanical stress. An example is photoluminescence created when photons (electromagnetic radiation) strike a substance and are absorbed, resulting in the emission of a resonant fluorescent or phosphorescent albedo. In planetary science, there exists X-ray fluorescence induced by sunlight absorbed by a regolith a property used to measure some of the chemical composition of the Moon s surface during the Apollo program. However, there exists an equally important phenomenon in planetary science which will be designated here as photon luminescence. It is not conventional photoluminescence because the incoming radiation that strikes the planetary surface is not photons but rather cosmic rays (CRs). Nevertheless, the result is the same: the generation of a photon albedo. In particular, Galactic CRs (GCRs) and solar energetic particles (SEPs) both induce a photon albedo that radiates from the surface of the Moon. Other particle albedos are generated as well, most of which are hazardous (e.g. neutrons). The photon luminescence or albedo of the lunar surface induced by GCRs and SEPs will be derived here, demonstrating that the Moon literally glows in the dark (when there is no sunlight or Earthshine). This extends earlier work on the same subject [1-4]. A side-by-side comparison of these two albedos and related mitigation measures will also be discussed.

The value of knowing better - Losses from natural hazards

NASA Astrophysics Data System (ADS)

Mysiak, J.; Galarraga, I.,; Garrido, A.; Interwies, E.; van Bers, C.; Vandenberghe, V.; Farinosi, F.; Foudi, S.; Görlitz, S.; Hernández-Mora, N.; Gil, M.; Grambow, C.

2012-04-01

In a highly emotional speech delivered last year after a series of strikes, Julia Gilbert, the Australian PM, noted that Australia has watched in horror as day after day a new chapter in natural disaster history has been written. And so did the whole world. 2011 went on to become the costliest year in terms of natural hazard losses in the recent history, with the total costs topping 380 billion US dollars. Almost a half of the insured losses were caused by a single event - the Fukushima Dai'ichi nuclear power plant accident triggered by a tsunami that followed an earthquake of MW 6.6 (Richer 9.0) magnitude. The Fukushima disaster has taught a costly lesson, once again: What you least expect, happens. The estimates of losses inflicted by natural hazards are, to put it mildly, incomplete and hardly representative of the ripple effects on regional and global economy, and the wider effects on social fabric, wellbeing and ecosystems that are notoriously difficult to monetise. The knowledge of the full magnitude of losses is not an end in itself. The economics of disasters is an emerging academic field, struggling to uncover the patterns of vulnerability to natural hazards, and provide insights useful for designing effective disaster risk reduction measures and policies. Yet the costly lessons learned are often neglected. In this paper we analyse selected significantly damaging events caused by hydrometeorological and climatologic events (floods and droughts) in four river basins/countries: Ebro/Spain, Po/Italy, Weser/Germany and Scheldt/Flanders-Belgium. Our analysis is focussed on identifying the gaps in reported damage estimates, and conducting additional original research and assessment that contribute to filling those gaps. In the case of drought, all the reference cases except the Ebro refer to the exceptionally hot and dry summer 2003. The drought event examined in the Ebro river basin is the prolonged period of deficient precipitation between 2004 and 2008. The flood reference cases are more uniformly distributed both intra- and interannually. They include Jan-Feb 2003 and Mar-Apr 2007 flood in the Ebro basin, the Oct 2000 flood in Po basin, Jul 2002 flood in Weser basin and Nov 2010 flood in the Scheldt. We have identified significant knowledge gaps in the current accounts of the impacts inflicted by the above disaster strikes. Almost no information is available about intangible, indirect and environmental costs. The structural damage is only partly examined. The existing assessment studies are based either on self-reported losses of the affected subjects and methodologies yielding divergent results about the extent (or even order of magnitude) of the losses suffered. The studies are rarely subjected to a critical analysis and quality check. Uncertainty surrounding the damage estimates is either omitted or reported only as a range of the likely magnitude of the disaster costs. Our analysis offers a systematic review of the damage across the affected sectors and communities. A number of assessment techniques were applied and their, pros and cons discussed. The paper highlights the value of an in-depth assessment of significantly damaging events for a better understanding of vulnerability, that is likely to be amplified as a result of anthropogenic climate change and economic development in the hazard-prone areas.

Transpressional Tectonics across the N. American-Caribbean Plate Boundary: Preliminary Results of a Multichannel Seismic Survey of Lake Azuei, Haiti.

NASA Astrophysics Data System (ADS)

Hearn, C. K.; Cormier, M. H.; Sloan, H.; Wattrus, N. J.; Boisson, D.; Brown, B.; Guerrier, K.; King, J. W.; Knotts, P.; Momplaisir, R.; Sorlien, C. C.; Stempel, R.; Symithe, S. J.; Ulysse, S. M. J.

2017-12-01

On January 12, 2010, a Mw 7.0 earthquake struck Haiti, killing over 200,000 people and devastating the Capital city of Port-au-Prince and the surrounding regions. It ruptured a previously unknown blind-thrust fault that abuts the Enriquillo Plantain Garden Fault (EPGF), one of two transform faults that define the North American-Caribbean plate boundary. That earthquake highlighted how transpression across this complex boundary is accommodated by slip partitioning into strike-slip and compressional structures. Because the seismic hazard is higher for a rupture on a reverse or oblique-slip fault than on a vertical strike-slip fault, the need to characterize the geometry of that fault system is clear. Lake Azuei overlies this plate boundary 60 km east of the 2010 epicenter. The lake's 23 km long axis trends NW-SE, parallel to the Haitian fold-and-thrust belt and oblique to the EPGF. This tectonic context makes it an ideal target for investigating the partitioning of plate motion between strike-slip and compressional structures. In January 2017, we acquired 222 km of multichannel seismic (MCS) profiles in the lake, largely concurrent with subbottom seismic (CHIRP) profiles. The MCS data were acquired using a high-frequency BubbleGun source and a 75 m-long, 24-channel streamer, achieving a 24 seismic fold with a penetration of 200 m below lakebed. With the goal of resolving tectonic structures in 3-D, survey lines were laid out in a grid with profiles spaced 1.2 km apart. Additional profiles were acquired at the SE end of the lake where most of the tectonic activity is presumably occurring. The co-located CHIRP and MCS profiles document the continuity of tectonic deformation between the surficial sediments and the deeper strata. Preliminary processing suggests that a SW-dipping blind thrust fault, expressed updip as a large monocline fold, may control the western edge of the lake. Gentle, young folds that protrude from the flat lakebed are also imaged with the CHIRP data. No obvious strike-slip faults are revealed in the MCS or CHIRP imagery. This result is consistent with a published analysis of GPS measurements that suggests oblique convergence on a south-dipping reverse fault along the southern shore of the lake.

Complex rupture process of the Mw 7.8, 2016, Kaikoura earthquake, New Zealand, and its aftershock sequence

NASA Astrophysics Data System (ADS)

Cesca, S.; Zhang, Y.; Mouslopoulou, V.; Wang, R.; Saul, J.; Savage, M.; Heimann, S.; Kufner, S.-K.; Oncken, O.; Dahm, T.

2017-11-01

The M7.8 Kaikoura Earthquake that struck the northeastern South Island, New Zealand, on November 14, 2016 (local time), is one of the largest ever instrumentally recorded earthquakes in New Zealand. It occurred at the southern termination of the Hikurangi subduction margin, where the subducting Pacific Plate transitions into the dextral Alpine transform fault. The earthquake produced significant distributed uplift along the north-eastern part of the South Island, reaching a peak amplitude of ∼8 m, which was accompanied by large (≥10 m) horizontal coseismic displacements at the ground surface along discrete active faults. The seismic waveforms' expression of the main shock indicate a complex rupture process. Early automated centroid moment tensor solutions indicated a strong non-double-couple term, which supports a complex rupture involving multiple faults. The hypocentral distribution of aftershocks, which appears diffuse over a broad region, clusters spatially along lineaments with different orientations. A key question of global interest is to shed light on the mechanism with which such a complex rupture occurred, and whether the underlying plate-interface was involved in the rupture. The consequences for seismic hazard of such a distributed, shallow faulting is important to be assessed. We perform a broad seismological analysis, combining regional and teleseismic seismograms, GPS and InSAR, to determine the rupture process of the main shock and moment tensors of 118 aftershocks down to Mw 4.2. The joint interpretation of the main rupture and aftershock sequence allow reconstruction of the geometry, and suggests sequential activation and slip distribution on at least three major active fault domains. We find that the rupture nucleated as a weak strike-slip event along the Humps Fault, which progressively propagated northward onto a shallow reverse fault, where most of the seismic moment was released, before it triggered slip on a second set of strike-slip faults at the northern end of the rupture. The northern and southern strike-slip fault domains have the same orientation but are spatially separated by >15 km. In our model, the low angle splay thrust fault is located above the slab and connects the strike-slip faults kinematically. During the aftershock phase, the entire fault system remained active.

Earthquake scaling laws for rupture geometry and slip heterogeneity

NASA Astrophysics Data System (ADS)

Thingbaijam, Kiran K. S.; Mai, P. Martin; Goda, Katsuichiro

2016-04-01

We analyze an extensive compilation of finite-fault rupture models to investigate earthquake scaling of source geometry and slip heterogeneity to derive new relationships for seismic and tsunami hazard assessment. Our dataset comprises 158 earthquakes with a total of 316 rupture models selected from the SRCMOD database (http://equake-rc.info/srcmod). We find that fault-length does not saturate with earthquake magnitude, while fault-width reveals inhibited growth due to the finite seismogenic thickness. For strike-slip earthquakes, fault-length grows more rapidly with increasing magnitude compared to events of other faulting types. Interestingly, our derived relationship falls between the L-model and W-model end-members. In contrast, both reverse and normal dip-slip events are more consistent with self-similar scaling of fault-length. However, fault-width scaling relationships for large strike-slip and normal dip-slip events, occurring on steeply dipping faults (δ~90° for strike-slip faults, and δ~60° for normal faults), deviate from self-similarity. Although reverse dip-slip events in general show self-similar scaling, the restricted growth of down-dip fault extent (with upper limit of ~200 km) can be seen for mega-thrust subduction events (M~9.0). Despite this fact, for a given earthquake magnitude, subduction reverse dip-slip events occupy relatively larger rupture area, compared to shallow crustal events. In addition, we characterize slip heterogeneity in terms of its probability distribution and spatial correlation structure to develop a complete stochastic random-field characterization of earthquake slip. We find that truncated exponential law best describes the probability distribution of slip, with observable scale parameters determined by the average and maximum slip. Applying Box-Cox transformation to slip distributions (to create quasi-normal distributed data) supports cube-root transformation, which also implies distinctive non-Gaussian slip distributions. To further characterize the spatial correlations of slip heterogeneity, we analyze the power spectral decay of slip applying the 2-D von Karman auto-correlation function (parameterized by the Hurst exponent, H, and correlation lengths along strike and down-slip). The Hurst exponent is scale invariant, H = 0.83 (± 0.12), while the correlation lengths scale with source dimensions (seismic moment), thus implying characteristic physical scales of earthquake ruptures. Our self-consistent scaling relationships allow constraining the generation of slip-heterogeneity scenarios for physics-based ground-motion and tsunami simulations.

Structurally controlled 'teleconnection' of large-scale mass wasting (Eastern Alps)

NASA Astrophysics Data System (ADS)

Ostermann, Marc; Sanders, Diethard

2015-04-01

In the Brenner Pass area (Eastern Alps) , closely ahead of the most northward outlier ('nose') of the Southern-Alpine continental indenter, abundant deep-seated gravitational slope deformations and a cluster of five post-glacial rockslides are present. The indenter of roughly triangular shape formed during Neogene collision of the Southern-Alpine basement with the Eastern-Alpine nappe stack. Compression by the indenter activated a N-S striking, roughly W-E extensional fault northward of the nose of the indenter (Brenner-normal fault; BNF), and lengthened the Eastern-Alpine edifice along a set of major strike-slip faults. These fault zones display high seismicity, and are the preferred locus of catastrophic rapid slope failures (rockslides, rock avalanches) and deep-seated gravitational slope deformations. The seismotectonic stress field, earthquake activity, and structural data all indicate that the South-Alpine indenter still - or again - exerts compression; in consequence, the northward adjacent Eastern Alps are subject mainly to extension and strike-slip. For the rockslides in the Brenner Pass area, and for the deep-seated gravitational slope deformations, the fault zones combined with high seismic activity predispose massive slope failures. Structural data and earthquakes mainly record ~W-E extension within an Eastern Alpine basement block (Oetztal-Stubai basement complex) in the hangingwall of the BNF. In the Northern Calcareous Alps NW of the Oetztal-Stubai basement complex, dextral faults provide defacement scars for large rockfalls and rockslides. Towards the West, these dextral faults merge into a NNW-SSE striking sinistral fault zone that, in turn, displays high seismic activity and is the locus of another rockslide cluster (Fern Pass cluster; Prager et al., 2008). By its kinematics dictated by the South-Alpine indenter, the relatively rigid Oetztal-Stubai basement block relays faulting and associated mass-wasting over a N-S distance of more than 60 kilometers - from the Brenner Pass area located along the crestline of the Alps to mount Zugspitze near the northern fringe of the Northern Calcareous Alps. Major fault zones and intercalated rigid blocks thus can 'teleconnect' zones of preferred mass-wasting over large lateral distances in orogens. Reference: Prager, C., Zangerl, C., Patzelt, G., Brandner, R., 2008. Age distribution of fossil landslides in the Tyrol (Austria) and its surrounding areas. Natural Hazards and Earth System Science 8, 377-407.

First Cloud-to-Ground Lightning Timing Study

NASA Technical Reports Server (NTRS)

Huddleston, Lisa L.

2013-01-01

NASA's LSP, GSDO and other programs use the probability of cloud-to-ground (CG) lightning occurrence issued by the 45th Weather Squadron (45 WS) in their daily and weekly lightning probability forecasts. These organizations use this information when planning potentially hazardous outdoor activities, such as working with fuels, or rolling a vehicle to a launch pad, or whenever personnel will work outside and would be at-risk from lightning. These organizations would benefit greatly if the 45 WS could provide more accurate timing of the first CG lightning strike of the day. The Applied Meteorology Unit (AMU) has made significant improvements in forecasting the probability of lightning for the day, but forecasting the time of the first CG lightning with confidence has remained a challenge. To address this issue, the 45 WS requested the AMU to determine if flow regimes, wind speed categories, or a combination of the two could be used to forecast the timing of the first strike of the day in the Kennedy Space Center (KSC)/Cape Canaveral Air Force Station (CCAFS) lightning warning circles. The data was stratified by various sea breeze flow regimes and speed categories in the surface to 5,000-ft layer. The surface to 5,000-ft layer was selected since that is the layer the 45 WS uses to predict the behavior of sea breeze fronts, which are the dominant influence on the occurrence of first lightning in Florida during the warm season. Due to small data sample sizes after stratification, the AMU could not determine a statistical relationship between flow regimes or speed categories and the time of the first CG strike.. As expected, although the amount and timing of lightning activity varies by time of day based on the flow regimes and speed categories, there are extended tails of low lightning activity making it difficult to specify times when the threat of the first lightning flash can be avoided. However, the AMU developed a graphical user interface with input from the 45 WS that allows forecasters to visualize the climatological frequencies of the timing of the first lightning strike. This tool should contribute directly to the 45 WS goal of improving lightning timing capability for its NASA, US Air Force and commercial customers.

Foot-strike pattern and performance in a marathon.

PubMed

Kasmer, Mark E; Liu, Xue-Cheng; Roberts, Kyle G; Valadao, Jason M

2013-05-01

To determine prevalence of heel strike in a midsize city marathon, if there is an association between foot-strike classification and race performance, and if there is an association between foot-strike classification and gender. Foot-strike classification (forefoot, midfoot, heel, or split strike), gender, and rank (position in race) were recorded at the 8.1-km mark for 2112 runners at the 2011 Milwaukee Lakefront Marathon. 1991 runners were classified by foot-strike pattern, revealing a heel-strike prevalence of 93.67% (n = 1865). A significant difference between foot-strike classification and performance was found using a Kruskal-Wallis test (P < .0001), with more elite performers being less likely to heel strike. No significant difference between foot-strike classification and gender was found using a Fisher exact test. In addition, subgroup analysis of the 126 non-heel strikers found no significant difference between shoe wear and performance using a Kruskal-Wallis test. The high prevalence of heel striking observed in this study reflects the foot-strike pattern of most mid-distance to long-distance runners and, more important, may predict their injury profile based on the biomechanics of a heel-strike running pattern. This knowledge can help clinicians appropriately diagnose, manage, and train modifications of injured runners.

Source model and Coulomb stress change of 2017 Mw 6.5 Philippine (Ormoc) Earthquake revealed by SAR interferometry

NASA Astrophysics Data System (ADS)

Tsai, M. C.; Hu, J. C.; Yang, Y. H.; Hashimoto, M.; Aurelio, M.; Su, Z.; Escudero, J. A.

2017-12-01

Multi-sight and high spatial resolution interferometric SAR data enhances our ability for mapping detailed coseismic deformation to estimate fault rupture model and to infer the Coulomb stress change associated with a big earthquake. Here, we use multi-sight coseismic interferograms acquired by ALOS-2 and Sentinel-1A satellites to estimate the fault geometry and slip distribution on the fault plane of the 2017 Mw 6.5 Ormoc Earthquake in Leyte island of Philippine. The best fitting model predicts that the coseismic rupture occurs along a fault plane with strike of 325.8º and dip of 78.5ºE. This model infers that the rupture of 2017 Ormoc earthquake is dominated by left-lateral slip with minor dip-slip motion, consistent with the left-lateral strike-slip Philippine fault system. The fault tip has propagated to the ground surface, and the predicted coseismic slip on the surface is about 1 m located at 6.5 km Northeast of Kananga city. Significant slip is concentrated on the fault patches at depth of 0-8 km and an along-strike distance of 20 km with varying slip magnitude from 0.3 m to 2.3 m along the southwest segment of this seismogenic fault. Two minor coseismic fault patches are predicted underneath of the Tononan geothermal field and the creeping segment of the northwest portion of this seismogenic fault. This implies that the high geothermal gradient underneath of the Tongonan geothermal filed could prevent heated rock mass from the coseismic failure. The seismic moment release of our preferred fault model is 7.78×1018 Nm, equivalent to Mw 6.6 event. The Coulomb failure stress (CFS) calculated by the preferred fault model predicts significant positive CFS change on the northwest segment of the Philippine fault in Leyte Island which has coseismic slip deficit and is absent from aftershocks. Consequently, this segment should be considered to have increasing of risk for future seismic hazard.

Structure of the San Fernando Valley region, California: implications for seismic hazard and tectonic history

USGS Publications Warehouse

Langenheim, V.E.; Wright, T.L.; Okaya, D.A.; Yeats, R.S.; Fuis, G.S.; Thygesen, K.; Thybo, H.

2011-01-01

Industry seismic reflection data, oil test well data, interpretation of gravity and magnetic data, and seismic refraction deep-crustal profiles provide new perspectives on the subsurface geology of San Fernando Valley, home of two of the most recent damaging earthquakes in southern California. Seismic reflection data provide depths to Miocene–Quaternary horizons; beneath the base of the Late Miocene Modelo Formation are largely nonreflective rocks of the Middle Miocene Topanga and older formations. Gravity and seismic reflection data reveal the North Leadwell fault zone, a set of down-to-the-north faults that does not offset the top of the Modelo Formation; the zone strikes northwest across the valley, and may be part of the Oak Ridge fault system to the west. In the southeast part of the valley, the fault zone bounds a concealed basement high that influenced deposition of the Late Miocene Tarzana fan and may have localized damage from the 1994 Northridge earthquake. Gravity and seismic refraction data indicate that the basin underlying San Fernando Valley is asymmetric, the north part of the basin (Sylmar subbasin) reaching depths of 5–8 km. Magnetic data suggest a major boundary at or near the Verdugo fault, which likely started as a Miocene transtensional fault, and show a change in the dip sense of the fault along strike. The northwest projection of the Verdugo fault separates the Sylmar subbasin from the main San Fernando Valley and coincides with the abrupt change in structural style from the Santa Susana fault to the Sierra Madre fault. The Simi Hills bound the basin on the west and, as defined by gravity data, the boundary is linear and strikes ~N45°E. That northeast-trending gravity gradient follows both the part of the 1971 San Fernando aftershock distribution called the Chatsworth trend and the aftershock trends of the 1994 Northridge earthquake. These data suggest that the 1971 San Fernando and 1994 Northridge earthquakes reactivated portions of Miocene normal faults.

Seismotectonics of Bhutan: Evidence for segmentation of the Eastern Himalayas and link to foreland deformation

NASA Astrophysics Data System (ADS)

Diehl, Tobias; Singer, Julia; Hetényi, György; Grujic, Djordje; Clinton, John; Giardini, Domenico; Kissling, Edi

2017-04-01

The instrumental seismicity of Bhutan is characterized by a lower activity compared to most other parts of the Himalayan arc. To understand this low activity and its impact on the seismic hazard, a seismic network was installed in Bhutan for 22 months between 2013 and 2014. From the recorded seismicity, earthquake moment tensors, and local earthquake tomography, we reveal along-strike variations in structure and crustal deformation regime. Imaged structural variations, primarily a thickened crust in western Bhutan, suggest lateral differences in stresses on the Main Himalayan Thrust (MHT), potentially affecting interseismic coupling and style of deformation. Sikkim, western Bhutan, and its foreland are characterized by strike-slip faulting in the Indian basement. Strain is particularly localized along a NW-SE striking dextral fault zone reaching from Chungthang in northeast Sikkim to Dhubri at the northwestern edge of the Shillong Plateau in the foreland. The dextral Dhubri-Chungthang fault zone (DCF) might segment the MHT between eastern Nepal and western Bhutan and connect the deformation front of the Himalaya with the Shillong Plateau in the foreland by forming the western boundary of a West-Assam block. In contrast, the eastern boundary of this block, hitherto associated with the Kopili foreland fault, appears to be diffuse. In eastern Bhutan, we image a seismogenic, flat portion of the MHT, which might be related to a partially creeping fault segment or increased background seismicity originating from the 2009 MW6.1 earthquake. In western-central Bhutan, clusters of micro-earthquakes at the front of the High-Himalayas indicate the presence of a mid-crustal ramp and stress buildup on a fully coupled MHT. The area bounded by the DCF in the west and the seismogenic MHT in the east has the potential for M7-8 earthquakes in Bhutan. Similarly, the DCF has the potential to host M7 earthquakes beneath the densely populated foreland basin as documented by the Dhubri earthquake of 1930, which is likely associated to this structure.

Seismotectonics of Bhutan: Evidence for segmentation of the Eastern Himalayas and link to foreland deformation

NASA Astrophysics Data System (ADS)

Diehl, Tobias; Singer, Julia; Hetényi, György; Grujic, Djordje; Clinton, John; Giardini, Domenico; Kissling, Edi; Gansser Working Group

2017-08-01

The instrumental record of Bhutan is characterized by a lower seismicity compared to other parts of the Himalayan arc. To understand this low activity and its impact on the seismic hazard, a seismic network was installed in Bhutan for 22 months between 2013 and 2014. Recorded seismicity, earthquake moment tensors and local earthquake tomography reveal along-strike variations in structure and crustal deformation regime. A thickened crust imaged in western Bhutan suggests lateral differences in stresses on the Main Himalayan Thrust (MHT), potentially affecting the interseismic coupling and deformation regime. Sikkim, western Bhutan and its foreland are characterized by strike-slip faulting in the Indian basement. Strain is particularly localized along a NW-SE striking mid-crustal fault zone reaching from Chungthang in northeast Sikkim to Dhubri at the northwestern edge of the Shillong Plateau in the foreland. The dextral Dhubri-Chungthang fault zone (DCF) causes segmentation of the Indian basement and the MHT between eastern Nepal and western Bhutan and connects the deformation front of the Himalaya with the Shillong Plateau by forming the western boundary of the Shillong block. The Kopili fault, the proposed eastern boundary of this block, appears to be a diffuse zone of mid-crustal seismicity in the foreland. In eastern Bhutan we image a seismogenic, flat portion of the MHT, which might be either related to a partially creeping segment or to increased background seismicity originating from the 2009 MW 6.1 earthquake. In western-central Bhutan clusters of micro-earthquakes at the front of the High-Himalayas indicate the presence of a mid-crustal ramp and stress buildup on a fully coupled MHT. The area bounded by the DCF in the west and the seismogenic MHT in the east has the potential for M7-8 earthquakes in Bhutan. Similarly, the DCF has the potential to host M7 earthquakes as documented by the 2011 Sikkim and the 1930 Dhubri earthquakes, which were potentially associated with this structure.

A kinematic method for footstrike pattern detection in barefoot and shod runners.

PubMed

Altman, Allison R; Davis, Irene S

2012-02-01

Footstrike patterns during running can be classified discretely into a rearfoot strike, midfoot strike and forefoot strike by visual observation. However, the footstrike pattern can also be classified on a continuum, ranging from 0% to 100% (extreme rearfoot to extreme forefoot) using the strike index, a measure requiring force plate data. When force data are not available, an alternative method to quantify the strike pattern must be used. The purpose of this paper was to quantify the continuum of foot strike patterns using an easily attainable kinematic measure, and compare it to the strike index measure. Force and kinematic data from twenty subjects were collected as they ran across an embedded force plate. Strike index and the footstrike angle were identified for the four running conditions of rearfoot strike, midfoot strike and forefoot strike, as well as barefoot. The footstrike angle was calculated as the angle of the foot with respect to the ground in the sagittal plane. Results indicated that the footstrike angle was significantly correlated with strike index. The linear regression model suggested that strike index can be accurately estimated, in both barefoot and shod conditions, in the absence of force data. Copyright © 2011 Elsevier B.V. All rights reserved.

What Controls Subduction Earthquake Size and Occurrence?

NASA Astrophysics Data System (ADS)

Ruff, L. J.

2008-12-01

There is a long history of observational studies on the size and recurrence intervals of the large underthrusting earthquakes in subduction zones. In parallel with this documentation of the variability in both recurrence times and earthquake sizes -- both within and amongst subduction zones -- there have been numerous suggestions for what controls size and occurrence. In addition to the intrinsic scientific interest in these issues, there are direct applications to hazards mitigation. In this overview presentation, I review past progress, consider current paradigms, and look toward future studies that offer some resolution of long- standing questions. Given the definition of seismic moment, earthquake size is the product of overall static stress drop, down-dip fault width, and along-strike fault length. The long-standing consensus viewpoint is that for the largest earthquakes in a subduction zone: stress-drop is constant, fault width is the down-dip extent of the seismogenic portion of the plate boundary, but that along-strike fault length can vary from one large earthquake to the next. While there may be semi-permanent segments along a subduction zone, successive large earthquakes can rupture different combinations of segments. Many investigations emphasize the role of asperities within the segments, rather than segment edges. Thus, the question of earthquake size is translated into: "What controls the along-strike segmentation, and what determines which segments will rupture in a particular earthquake cycle?" There is no consensus response to these questions. Over the years, the suggestions for segmentation control include physical features in the subducted plate, physical features in the over-lying plate, and more obscure -- and possibly ever-changing -- properties of the plate interface such as the hydrologic conditions. It seems that the full global answer requires either some unforeseen breakthrough, or the long-term hard work of falsifying all candidate hypotheses except one. This falsification process requires both concentrated multidisciplinary efforts and patience. Large earthquake recurrence intervals in the same subduction zone segment display a significant, and therefore unfortunate, variability. Over the years, many of us have devised simple models to explain this variability. Of course, there are also more complicated explanations with many additional model parameters. While there has been important observational progress as both historical and paleo-seismological studies continue to add more data pairs of fault length and recurrence intervals, there has been a frustrating lack of progress in elimination of candidate models or processes that explain recurrence time variability. Some of the simple models for recurrence times offer a probabilistic or even deterministic prediction of future recurrence times - and have been used for hazards evaluation. It is important to know if these models are correct. Since we do not have the patience to wait for a strict statistical test, we must find other ways to test these ideas. For example, some of the simple deterministic models for along-strike segment interaction make predictions for variation in tectonic stress state that can be tested during the inter-seismic period. We have seen how some observational discoveries in the past decade (e.g., the episodic creep events down-dip of the seismogenic zone) give us additional insight into the physical processes in subduction zones; perhaps multi-disciplinary studies of subduction zones will discover a new way to reliably infer large-scale shear stresses on the plate interface?

Deterministic seismogenic scenarios based on asperities spatial distribution to assess tsunami hazard on northern Chile (18°S to 24°S)

NASA Astrophysics Data System (ADS)

González-Carrasco, J. F.

2016-12-01

Southern Peru and northern Chile coastal areas, extended between 12º to 24ºS, have been recognized as a mature seismic gap with a high seismogenic potential associated to seismic moment deficit accumulated since 1877. An important scientific question is which will be the breaking pattern of a future megathrust earthquake, being relevant from hazard assessment perspective. During the last decade, the occurrence of three major subduction earthquakes has given the possibility to acquire outstanding geophysical and geological information to know the behavior of phenomena. An interesting result is the relationship between the maximum slip areas and the spatial distribution of asperities in subduction zones. In this contribution, we propose a methodology to identify a regional pattern of main asperities to construct reliable seismogenic scenarios in a seismic gap. We follow a deterministic approach to explore the distribution of asperities segmentation using geophysical and geodetic data as trench-parallel gravity anomaly (TPGA), interseismic coupling (ISC), b-value, historical moment release, residual bathymetric and gravity anomalies. The combined information represents physical constraints for short and long term suitable regions for future mega earthquakes. To illuminate the asperities distribution, we construct profiles using fault coordinates, along-strike and down-dip direction, of all proxies to define the boundaries of a major asperities (> 100 km). The geometry of a major asperity is useful to define a finite set of future deterministic seismogenic scenarios to evaluate tsunamigenic hazard in main cities of northern zone of Chile (18°S to 24°S).

Indirect Lightning Safety Assessment Methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ong, M M; Perkins, M P; Brown, C G

2009-04-24

Lightning is a safety hazard for high-explosives (HE) and their detonators. In the However, the current flowing from the strike point through the rebar of the building The methodology for estimating the risk from indirect lighting effects will be presented. It has two parts: a method to determine the likelihood of a detonation given a lightning strike, and an approach for estimating the likelihood of a strike. The results of these two parts produce an overall probability of a detonation. The probability calculations are complex for five reasons: (1) lightning strikes are stochastic and relatively rare, (2) the quality ofmore » the Faraday cage varies from one facility to the next, (3) RF coupling is inherently a complex subject, (4) performance data for abnormally stressed detonators is scarce, and (5) the arc plasma physics is not well understood. Therefore, a rigorous mathematical analysis would be too complex. Instead, our methodology takes a more practical approach combining rigorous mathematical calculations where possible with empirical data when necessary. Where there is uncertainty, we compensate with conservative approximations. The goal is to determine a conservative estimate of the odds of a detonation. In Section 2, the methodology will be explained. This report will discuss topics at a high-level. The reasons for selecting an approach will be justified. For those interested in technical details, references will be provided. In Section 3, a simple hypothetical example will be given to reinforce the concepts. While the methodology will touch on all the items shown in Figure 1, the focus of this report is the indirect effect, i.e., determining the odds of a detonation from given EM fields. Professor Martin Uman from the University of Florida has been characterizing and defining extreme lightning strikes. Using Professor Uman's research, Dr. Kimball Merewether at Sandia National Laboratory in Albuquerque calculated the EM fields inside a Faraday-cage type facility, when the facility is struck by lightning. In the following examples we will use Dr. Merewether's calculations from a poor quality Faraday cage as the input for the RF coupling analysis. coupling of radio frequency (RF) energy to explosive components is an indirect effect of currents [1]. If HE is adequately separated from the walls of the facility that is struck by disassembled have been turned into Faraday-cage structures to protect against lightning is initiation of the HE. last couple of decades, DOE facilities where HE is manufactured, assembled, stored or lightning. The most sensitive component is typically a detonator, and the safety concern lightning, electrons discharged from the clouds should not reach the HE components. radio receiver, the metal cable of a detonator can extract energy from the EM fields. This to the earth will create electromagnetic (EM) fields in the facility. Like an antenna in a« less

Active shortening of the Cascadia forearc and implications for seismic hazards of the Puget Lowland

USGS Publications Warehouse

Johnson, S.Y.; Blakely, R.J.; Stephenson, W.J.; Dadisman, S.V.; Fisher, M.A.

2004-01-01

Margin-parallel shortening of the Cascadia forearc is a consequence of oblique subduction of the Juan de Fuca plate beneath North America. Strike-slip, thrust, and oblique crustal faults beneath the densely populated Puget Lowland accommodate much of this north-south compression, resulting in large crustal earthquakes. To better understand this forearc deformation and improve earthquake hazard, assessment, we here use seismic reflection surveys, coastal exposures of Pleistocene strata, potential-field data, and airborne laser swath mapping to document and interpret a significant structural boundary near the City of Tacoma. This boundary is a complex structural zone characterized by two distinct segments. The northwest trending, eastern segment, extending from Tacoma to Carr Inlet, is formed by the broad (??? 11.5 km), southwest dipping (??? 11??-2??) Rosedale monocline. This monocline raises Crescent Formation basement about 2.5 km, resulting in a moderate gravity gradient. We interpret the Rosedale monocline as a fault-bend fold, forming above a deep thrust fault. Within the Rosedale monocline, inferred Quaternary strata thin northward and form a growth triangle that is 4.1 to 6.6 km wide at its base, suggesting ??? 2-3 mm/yr of slip on the underlying thrust. The western section of the >40-km-long, north dipping Tacoma fault, extending from Hood Canal to Carr Inlet, forms the western segment of the Tacoma basin margin. Structural relief on this portion of the basin margin may be several kilometers, resulting in steep gravity and aeromagnetic anomalies. Quaternary structural relief along the Tacoma fault is as much as 350-400 m, indicating a minimum slip rate of about 0.2 mm/yr. The inferred eastern section of the Tacoma fault (east of Carr Inlet) crosses the southern part of the Seattle uplift, has variable geometry along strike, and diminished structural relief. The Tacoma fault is regarded as a north dipping backthrust to the Seattle fault, so that slip on a master thrust fault at depth could result in movement on the Seattle fault, the Tacoma fault, or both.

Evidence of Enhanced Subrosion in a Fault Zone and Characterization of Hazard Zones with Elastic Parameters derived from SH-wave reflection Seismics and VSP

NASA Astrophysics Data System (ADS)

Wadas, S. H.; Tanner, D. C.; Tschache, S.; Polom, U.; Krawczyk, C. M.

2017-12-01

Subrosion, the dissolution of soluble rocks, e.g., sulfate, salt, or carbonate, requires unsaturated water and fluid pathways that enable the water to flow through the subsurface and generate cavities. Over time, different structures can occur that depend on, e.g., rock solubility, flow rate, and overburden type. The two main structures are sinkholes and depressions. To analyze the link between faults, groundwater flow, and soluble rocks, and to determine parameters that are useful to characterize hazard zones, several shear-wave (SH) reflection seismic profiles were surveyed in Thuringia in Germany, where Permian sulfate rocks and salt subcrop close to the surface. From the analysis of the seismic sections we conclude that areas affected by tectonic deformation phases are prone to enhanced subrosion. The deformation of fault blocks leads to the generation of a damage zone with a dense fracture network. This increases the rock permeability and thus serves as a fluid pathway for, e.g., artesian-confined groundwater. The more complex the fault geometry and the more interaction between faults, the more fractures are generated, e.g., in a strike slip-fault zone. The faults also act as barriers for horizontal groundwater flow perpendicular to the fault surfaces and as conduits for groundwater flow along the fault strike. In addition, seismic velocity anomalies and attenuation of seismic waves are observed. Low velocities <200 m/s and high attenuation may indicate areas affected by subrosion. Other parameters that characterize the underground stability are the shear modulus and the Vp/Vs ratio. The data revealed zones of low shear modulus <100 MPa and high Vp/Vs ratio >2.5, which probably indicate unstable areas due to subrosion. Structural analysis of S-wave seismics is a valuable tool to detect near-surface faults in order to determine whether or not an area is prone to subrosion. The recognition of even small fault blocks can help to better understand the hydrodynamic groundwater conditions, which is another key factor to understand the subrosion process. The elastic parameters derived from seismic velocities can help to identify possible zones of instability.

Mapping offshore portions of the Khlong Marui and Ranong faults in Thailand: Implications for seismic hazards in the Thai peninsula

NASA Astrophysics Data System (ADS)

Ramirez, H.; Furlong, K.; Pananont, P.; Krastel, S.; Nhongkai, S. N.

2017-12-01

Thailand experiences Mw < 6.5 earthquakes, but the frequency of these earthquakes is considerably less within Thailand than at plate boundaries. Faults in Thailand that are potentially active, but have not historically hosted a large earthquake pose an unknown seismic hazard. Two such faults are the Khlong Marui and Ranong faults, which are left lateral strike-slip faults that strike northeast across the Thai peninsula and have been assumed to continue into the Andaman Sea. The Ranong and Khlong Marui fault zones have clear surface expression onshore, but their offshore extent is unknown. An estimated 100 km of sinistral displacement has occurred in the last 52 million years on the Ranong fault zone and the Khlong Marui fault zone is assumed to be similar (Watkinson et al., 2008; Kornsawan and Morley, 2002). Five Mw < 4.5 earthquakes have occurred near the inferred offshore extension of the Ranong and Khlong Marui faults since 2005. However, the maximum earthquake magnitude possible and recurrence interval of events on these faults is unconstrained, leaving southern Thailand unprepared for a Mw < 6 earthquake. To constrain the location of offshore portion of these two faults we performed a marine seismic reflection survey in the Andaman Sea, and construct an offshore fault map. Additionally, we are working to resolve the depth extent of displacement associated with faulting in the seismic data to constrain the timing of fault motion. Using empirical scaling between fault area and earthquake size we will be able to estimate a maximum earthquake magnitude for the Ranong and Khlong Marui faults. This will provide additional information to help southern Thailand prepare for potential seismic events. Kornsawan, A., & Morley, C. K. (2002). The origin and evolution of complex transfer zones (graben shifts) in conjugate fault systems around the Funan Field, Pattani Basin, Gulf of Thailand. Journal of Structural Geology, 24(3), 435-449. http://doi.org/10.1016/S0191- 8141(01)00080-3 Watkinson, I., Elders, C., & Hall, R. (2008). The kinematic history of the Khlong Marui and Ranong Faults, southern Thailand. Journal of Structural Geology, 30, 1554-1571. http://doi.org/10.1016/j.jsg.2008.09.001

Issues and Outcomes of Teachers' Strikes, 1955-65.

ERIC Educational Resources Information Center

Goergen, Joseph H.; Keough, John J.

This study analyzes the patterns of 40 teacher strikes between 1955 and 1965 by looking at (1) the issues and demands and (2) the outcomes and settlements. It is hypothesized that (1) teacher strikes fall into discernible patterns, (2) functional relationships exist between certain strike issues and outcomes and the strike itself, (3) strikes can…

Deterministic Tectonic Origin Tsunami Hazard Analysis for the Eastern Mediterranean and its Connected Seas

NASA Astrophysics Data System (ADS)

Necmioglu, O.; Meral Ozel, N.

2014-12-01

Accurate earthquake source parameters are essential for any tsunami hazard assessment and mitigation, including early warning systems. Complex tectonic setting makes the a priori accurate assumptions of earthquake source parameters difficult and characterization of the faulting type is a challenge. Information on tsunamigenic sources is of crucial importance in the Eastern Mediterranean and its Connected Seas, especially considering the short arrival times and lack of offshore sea-level measurements. In addition, the scientific community have had to abandon the paradigm of a ''maximum earthquake'' predictable from simple tectonic parameters (Ruff and Kanamori, 1980) in the wake of the 2004 Sumatra event (Okal, 2010) and one of the lessons learnt from the 2011 Tohoku event was that tsunami hazard maps may need to be prepared for infrequent gigantic earthquakes as well as more frequent smaller-sized earthquakes (Satake, 2011). We have initiated an extensive modeling study to perform a deterministic Tsunami Hazard Analysis for the Eastern Mediterranean and its Connected Seas. Characteristic earthquake source parameters (strike, dip, rake, depth, Mwmax) at each 0.5° x 0.5° size bin for 0-40 km depth (total of 310 bins) and for 40-100 km depth (total of 92 bins) in the Eastern Mediterranean, Aegean and Black Sea region (30°N-48°N and 22°E-44°E) have been assigned from the harmonization of the available databases and previous studies. These parameters have been used as input parameters for the deterministic tsunami hazard modeling. Nested Tsunami simulations of 6h duration with a coarse (2 arc-min) and medium (1 arc-min) grid resolution have been simulated at EC-JRC premises for Black Sea and Eastern and Central Mediterranean (30°N-41.5°N and 8°E-37°E) for each source defined using shallow water finite-difference SWAN code (Mader, 2004) for the magnitude range of 6.5 - Mwmax defined for that bin with a Mw increment of 0.1. Results show that not only the earthquakes resembling the well-known historical earthquakes such as AD 365 or AD 1303 in the Hellenic Arc, but also earthquakes with lower magnitudes do constitute to the tsunami hazard in the study area.

Is the foot striking pattern more important than barefoot or shod conditions in running?

PubMed

Shih, Yo; Lin, Kuan-Lun; Shiang, Tzyy-Yuang

2013-07-01

People have advocated barefoot running, claiming that it is better suited to human nature. Humans usually run barefoot using a forefoot strike and run shod using a heel strike. The striking pattern was thought to be a key factor that contributes to the benefit of barefoot running. The purpose of this study is to use scientific data to prove that the striking pattern is more important than barefoot or shod conditions for runners on running injuries prevention. Twelve habitually male shod runners were recruited to run under four varying conditions: barefoot running with a forefoot strike, barefoot running with a heel strike, shod running with a forefoot strike, and shod running with a heel strike. Kinetic and kinematic data and electromyography signals were recorded during the experiments. The results showed that the lower extremity can gain more compliance when running with a forefoot strike. Habitually shod runners can gain more shock absorption by changing the striking pattern to a forefoot strike when running with shoes and barefoot conditions. Habitually shod runners may be subject to injuries more easily when they run barefoot while maintaining their heel strike pattern. Higher muscle activity in the gastrocnemius was observed when running with a forefoot strike, which may imply a greater training load on the muscle and a tendency for injury. Copyright © 2013 Elsevier B.V. All rights reserved.

The effects of preferred and non-preferred running strike patterns on tissue vibration properties.

PubMed

Enders, Hendrik; von Tscharner, Vinzenz; Nigg, Benno M

2014-03-01

To characterize soft tissue vibrations during running with a preferred and a non-preferred strike pattern in shoes and barefoot. Cross-sectional study. Participants ran at 3.5 m s(-1) on a treadmill in shoes and barefoot using a rearfoot and a forefoot strike for each footwear condition. The preferred strike patterns for the subjects were a rearfoot strike and a forefoot strike for shod and barefoot running, respectively. Vibrations were recorded with an accelerometer overlying the belly of the medial gastrocnemius. Thirteen non-linearly scaled wavelets were used for the analysis. Damping was calculated as the overall decay of power in the acceleration signal post ground contact. A higher damping coefficient indicates higher damping capacities of the soft tissue. The shod rearfoot strike showed a 93% lower damping coefficient than the shod forefoot strike (p<0.001). A lower damping coefficient indicates less damping of the vibrations. The barefoot forefoot strike showed a trend toward a lower damping coefficient compared to a barefoot rearfoot strike. Running barefoot with a forefoot strike resulted in a significantly lower damping coefficient than a forefoot strike when wearing shoes (p<0.001). The shod rearfoot strike showed lower damping compared to a barefoot rearfoot strike (p<0.001). While rearfoot striking showed lower vibration frequencies in shod and barefoot running, it did not consistently result in lower damping coefficients. This study showed that the use of a preferred movement resulted in lower damping coefficients of running related soft tissue vibrations. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

THE EFFECT OF STEP RATE MANIPULATION ON FOOT STRIKE PATTERN OF LONG DISTANCE RUNNERS.

PubMed

Allen, Darrell J; Heisler, Hollie; Mooney, Jennifer; Kring, Richard

2016-02-01

Running gait retraining to change foot strike pattern in runners from a heel strike pattern to a non heel- strike pattern has been shown to reduce impact forces and may help to reduce running related injuries. Step rate manipulation above preferred is known to help decrease step length, foot inclination angle, and vertical mass excursion, but has not yet been evaluated as a method to change foot strike pattern. The purpose of this study was to investigate the effect of step rate manipulation on foot strike pattern in shod recreational runners who run with a heel strike pattern. A secondary purpose was to describe the effect of step rate manipulation at specific percentages above preferred on foot inclination angle at initial contact. Forty volunteer runners, who were self-reported heel strikers and had a weekly running mileage of at least 10 miles, were recruited. Runners were confirmed to be heel strikers during the warm up period on the treadmill. The subject's step rate was determined at their preferred running pace. A metronome was used to increase step rate above the preferred step rate by 5%, 10% and 15%. 2D video motion analysis was utilized to determine foot strike pattern and to measure foot inclination angle at initial contact for each step rate condition. There was a statistically significant change in foot strike pattern from a heel strike pattern to a mid-foot or forefoot strike pattern at both 10% and 15% step rates above preferred. Seven of the 40 subjects (17.5%) changed from a heel- strike pattern to a non- heel strike pattern at +10% and 12 of the 40 subjects (30%) changed to a non-heel strike pattern at +15%. Mean foot inclination angle at initial contact showed a statistically significant change (reduction) as step rate increased. Step rate manipulation of 10% or greater may be enough to change foot strike pattern from a heel strike to a mid-foot or forefoot strike pattern in a small percentage of recreational runners who run in traditional running shoes. If changing the foot strike pattern is the main goal, other gait re-training methods may be needed to make a change from a heel strike to a non-heel strike pattern. Step rate manipulation shows a progressive reduction of foot inclination angle at 5%, 10%, and 15% above preferred step rate which reduces the severity of the heel strike at initial contact. Step rate manipulation of at least +10% above preferred may be an effective running gait retraining method for clinicians to decrease the severity of heel strike and possibly assist a runner to change to a non-heel strike pattern. 3.

Geometry and kinematics of accretionary wedge faults inherited from the structure and rheology of the incoming sedimentary section; insights from 3D seismic reflection data

NASA Astrophysics Data System (ADS)

Bell, Rebecca; Orme, Haydn; Lenette, Kathryn; Jackson, Christopher; Fitch, Peter; Phillips, Thomas; Moore, Gregory

2017-04-01

Intra-wedge thrust faults represent important conduits for fluid flow in accretionary prisms, modulating pore fluid pressure, effective stress and, ultimately, the seismic hazard potential of convergent plate boundaries. Despite its importance, we know surprisingly little regarding the 3D geometry and kinematics of thrust networks in accretionary prisms, largely due to a lack of 3D seismic reflection data providing high-resolution, 3D images. To address this we here present observations from two subduction zones, the Nankai and Lesser Antilles margins, where 3D seismic and borehole data allow us to constrain the geometry and kinematics of intra-wedge fault networks and to thus shed light on the mechanisms responsible for their structural style variability. At the Muroto transect, Nankai margin we find that the style of protothrust zone deformation varies markedly along-strike over distances of only a few km. Using structural restoration and quantitative fault analysis, we reveal that in the northern part of the study area deformation occurred by buckle folding followed by faulting. Further south, intra-wedge faults nucleate above the décollement and propagate radially with no folding, resulting in variable connectivity between faults and the décollement. The seismic facies character of sediments immediately above the décollement varies along strike, with borehole data revealing that, in the north, where buckle folding dominates un-cemented Lower Shikoku Basin sediments overlie the décollement. In contrast, further south, Opal CT-cemented, and thus rigid Upper Shikoku Basin sediments overlie the décollement. We suggest these along-strike variations in diagenesis and thus rheology control the observed structural style variability. Near Barbados, at the Lesser Antilles margin, rough subducting plate relief is blanketed by up to 700 m of sediment. 3D seismic data reveal that basement relief is defined by linear normal fault blocks and volcanic ridges, and sub-circular seamounts. The youngest, most basinward thrusts in the wedge strike NW-SE; however, 17 km landward, towards the wedge core, they strike NE-SW. The orientation of the more landward faults correlates with the trend of linear basement relief, whereas thrust fault orientations close to the deformation front are perpendicular to the convergence direction. We notice that oceanic crust that has been subducted is characterised by NE-SW striking, now-inverted normal faults, with some faults extending up through the entire sedimentary section. We suggest that the NE-SW orientation of thrust faults has been inherited from linear basement ridges. In contrast, basement currently subducting beneath the deformation front is dominated by seamounts and is devoid of more linear features. Here, there are no pre-existing normal faults available for reactivation and thrust faults develop perpendicular to the convergence direction. We show that the incoming plate properties have a profound effect on the geometry of accretionary wedges; it would be difficult to elucidate this without 3D seismic data. Our insights provide new hypotheses that can be tested with numerical and laboratory models.

Impact Hazard Monitoring: Theory and Implementation

NASA Astrophysics Data System (ADS)

Farnocchia, Davide

2015-08-01

Impact monitoring is a crucial component of the mitigation or elimination of the hazard posed by asteroid impacts. Once an asteroid is discovered, it is important to achieve an early detection and an accurate assessment of the risk posed by future Earth encounters. Here we review the most standard impact monitoring techniques. Linear methods are the fastest approach but their applicability regime is limited because of the chaotic dynamics of near-Earth asteroids, whose orbits are often scattered by planetary encounters. Among nonlinear methods, Monte Carlo algorithms are the most reliable ones. However, the large number of near-Earth asteroids and the computational load required to detect low probability impact events make Monte Carlo approaches impractical in the framework of monitoring all near-Earth asteroids. In the last 15 years, the Line of Variations (LOV) method has been the most successful technique as it strikes a remarkable compromise between computational efficiency and the capability of detecting low probability events deep in the nonlinear regime. As a matter of fact, the LOV method is the engine of JPL’s Sentry and University of Pisa’s NEODyS, which the two fully automated impact monitoring systems that routinely search for potential impactors among known near-Earth asteroids. We also present some more recent techniques developed to deal with the new challenges arising in the impact hazard assessment problem. In particular, we describe how to use keyhole maps to go beyond strongly scattering encounters and push forward in time the impact prediction horizon. In these cases asteroids usually have a very well constrained orbit and we often need to account for the action of nongravitational perturbations, especially the Yarkovsky effect. Finally, we discuss the short-term hazard assessment problem for newly discovered asteroids, when only a short observed arc is available. The limited amount of observational data generally leads to severe degeneracies in the orbit estimation process. We overcome these degeneracies by employing ranging techniques, which scan the poorly constrained space of topocentric range and range rate.

Principal facts for gravity data along the Hayward fault and vicinity, San Francisco Bay area, northern California

USGS Publications Warehouse

Ponce, David A.

2001-01-01

The U.S. Geological Survey (USGS) established over 940 gravity stations along the Hayward fault and vicinity. The Hayward fault, regarded as one of the most hazardous faults in northern California (Working Group on California Earthquake Probabilities, 1999), extends for about 90 km from Fremont in the southeast to San Pablo Bay in the northwest. The Hayward fault is predominantly a right-lateral strike-slip fault that forms the western boundary of the East Bay Hills. These data and associated physical property measurement were collected as part of on-going studies to help determine the earthquake hazard potential of major faults within the San Francisco Bay region. Gravity data were collected between latitude 37°30' and 38°15' N and longitude 121°45' and 122°30' W. Gravity stations were located on the following 7.5 minute quadrangles: Newark, Niles, San Leandro, Hayward, Dublin, Oakland West, Oakland East, Las Trampas Ridge, Diablo, Richmond, Briones Valley, Walnut Creek, and Clayton. All data were ultimately tied to primary gravity base station Menlo Park A, located on the campus of the U.S. Geological Survey in Menlo Park, Calif. (latitude 37°27.34' N, longitude 122°10.18' W, observed gravity value 979944.27 mGal).

“Educate the Individual . . . to a Sane Appreciation of the Risk”A History of Industry’s Responsibility to Warn of Job Dangers Before the Occupational Safety and Health Administration

PubMed Central

Markowitz, Gerald

2016-01-01

The Occupational Safety and Health Act of 1970 and the Workers Right to Know laws later in that decade were signature moments in the history of occupational safety and health. We have examined how and why industry leaders came to accept that it was the obligation of business to provide information about the dangers to health of the materials that workers encountered. Informing workers about the hazards of the job had plagued labor–management relations and fed labor disputes, strikes, and even pitched battles during the turn of the century decades. Industry’s rhetorical embrace of the responsibility to inform was part of its argument that government regulation of the workplace was not necessary because private corporations were doing it. PMID:26696286

"Educate the Individual... to a Sane Appreciation of the Risk" A History of Industry's Responsibility to Warn of Job Dangers Before the Occupational Safety and Health Administration.

PubMed

Rosner, David; Markowitz, Gerald

2016-01-01

The Occupational Safety and Health Act of 1970 and the Workers Right to Know laws later in that decade were signature moments in the history of occupational safety and health. We have examined how and why industry leaders came to accept that it was the obligation of business to provide information about the dangers to health of the materials that workers encountered. Informing workers about the hazards of the job had plagued labor-management relations and fed labor disputes, strikes, and even pitched battles during the turn of the century decades. Industry's rhetorical embrace of the responsibility to inform was part of its argument that government regulation of the workplace was not necessary because private corporations were doing it.

Application of Catastrophe Risk Modelling to Evacuation Public Policy

NASA Astrophysics Data System (ADS)

Woo, G.

2009-04-01

The decision by civic authorities to evacuate an area threatened by a natural hazard is especially fraught when the population in harm's way is extremely large, and where there is considerable uncertainty in the spatial footprint, scale, and strike time of a hazard event. Traditionally viewed as a hazard forecasting issue, civil authorities turn to scientists for advice on a potentially imminent dangerous event. However, the level of scientific confidence varies enormously from one peril and crisis situation to another. With superior observational data, meteorological and hydrological hazards are generally better forecast than geological hazards. But even with Atlantic hurricanes, the track and intensity of a hurricane can change significantly within a few hours. This complicated and delayed the decision to call an evacuation of New Orleans when threatened by Hurricane Katrina, and would present a severe dilemma if a major hurricane were appearing to head for New York. Evacuation needs to be perceived as a risk issue, requiring the expertise of catastrophe risk modellers as well as geoscientists. Faced with evidence of a great earthquake in the Indian Ocean in December 2004, seismologists were reluctant to give a tsunami warning without more direct sea observations. Yet, from a risk perspective, the risk to coastal populations would have warranted attempts at tsunami warning, even though there was significant uncertainty in the hazard forecast, and chance of a false alarm. A systematic coherent risk-based framework for evacuation decision-making exists, which weighs the advantages of an evacuation call against the disadvantages. Implicitly and qualitatively, such a cost-benefit analysis is undertaken by civic authorities whenever an evacuation is considered. With the progress in catastrophe risk modelling, such an analysis can be made explicit and quantitative, providing a transparent audit trail for the decision process. A stochastic event set, the core of a catastrophe risk model, is required to explore the casualty implications of different possible hazard scenarios, to assess the proportion of an evacuated population who would owe their lives to an evacuation, and to estimate the economic loss associated with an unnecessary evacuation. This paper will review the developing methodology for applying catastrophe risk modelling to support public policy in evacuation decision-making, and provide illustrations from across the range of natural hazards. Evacuation during volcanic crises is a prime example, recognizing the improving forecasting skill of volcanologists, now able to account probabilistically for precursory seismological, geodetic, and geochemical monitoring data. This methodology will be shown to help civic authorities make sounder risk-informed decisions on the timing and population segmentation of evacuation from both volcanoes and calderas, such as Vesuvius and Campi Flegrei, which are in densely populated urban regions.

Perspectives on the Near-Earth Object Impact Hazard After Chelyabinsk

NASA Astrophysics Data System (ADS)

Chapman, C. R.

2013-12-01

Until this year, the NEO impact hazard had been regarded as a theoretical example of a very low probability high consequence natural disaster. There had been no confirmed examples of fatalities directly due to asteroid or meteoroid strikes. (There still aren't.) The several megaton Tunguska event in 1908 was in a remote, unpopulated place. So human beings have been witnessing only the tiniest analogs of asteroid strikes, the night-sky meteors and occasional bolides, which - on rare occasions - yield meteoritic fragments that puncture holes in roofs. Though the NEO impact hazard has occasionally been treated in the natural hazards literature, interest primarily remained in the planetary science and aerospace communities. The Chelyabinsk asteroid impact on 15 February 2013 was a real disaster, occurring near a city with a population exceeding a million. Well over a thousand people were injured, thousands of buildings suffered at least superficial damage (mainly to windows), schools and sports facilities were closed, and emergency responders swarmed across the city and surrounding rural areas. While the consequences were very small compared with larger natural disasters, which kill tens of thousands of people annually worldwide, this specific case - for the first time - has permitted a calibration of the consequences of the rare impacts asteroid astronomers have been predicting. There now are reasons to expect that impacts by bodies tens of meters in diameter are several times more frequent than had been thought and each impact is more damaging than previously estimated. The Chelyabinsk event, produced by a 20 meter diameter asteroid, specifically suggests that asteroids just 15 meters diameter, or even smaller, could be very dangerous and damaging; indeed, a more common steeper impact angle would have produced more consequential damage on the ground. This contrasts with estimates a decade earlier [NASA NEO Science Definition Team report, 2003] that asteroids smaller than 40 to 50 meters diameter would explode harmlessly in the upper atmosphere. Given the observed size-frequency relation for NEOs, this means that dangerous impacts could be many tens of times more frequent than had been thought. New observing campaigns (e.g. ATLAS) oriented towards finding roughly half of the frequent smaller impactors meters to tens of meters in size during their final days to weeks before impact will soon result in warnings every few years of a potentially dangerous impact, perhaps requiring evacuation or instructions to shelter-in-place, even though most will turn out to be essentially harmless events. Warnings may become even more frequent as prudent emergency managers take into account the large uncertainties in sizes and destructive potential of these 'final plungers.' So emergency management officials around the world should at least be aware of the potential for a NEO impact to produce a real, if generally minor and local, natural disaster. Fortunately, success of the Spaceguard search for civilization-threatening large NEOs (> 1 km diameter) over the last 15 years has nearly retired the risk of global calamity by impact. So attention turns to the much smaller impacts that are far less dangerous, but soon will be frequently predicted and so cannot be ignored.

[Neurological diseases after lightning strike : Lightning strikes twice].

PubMed

Gruhn, K M; Knossalla, Frauke; Schwenkreis, Peter; Hamsen, Uwe; Schildhauer, Thomas A; Tegenthoff, Martin; Sczesny-Kaiser, Matthias

2016-06-01

Lightning strikes rarely occur but 85 % of patients have lightning-related neurological complications. This report provides an overview about different modes of energy transfer and neurological conditions related to lightning strikes. Moreover, two case reports demonstrate the importance of interdisciplinary treatment and the spectrum of neurological complications after lightning strikes.

Foot strike and injury rates in endurance runners: a retrospective study.

PubMed

Daoud, Adam I; Geissler, Gary J; Wang, Frank; Saretsky, Jason; Daoud, Yahya A; Lieberman, Daniel E

2012-07-01

This retrospective study tests if runners who habitually forefoot strike have different rates of injury than runners who habitually rearfoot strike. We measured the strike characteristics of middle- and long-distance runners from a collegiate cross-country team and quantified their history of injury, including the incidence and rate of specific injuries, the severity of each injury, and the rate of mild, moderate, and severe injuries per mile run. Of the 52 runners studied, 36 (69%) primarily used a rearfoot strike and 16 (31%) primarily used a forefoot strike. Approximately 74% of runners experienced a moderate or severe injury each year, but those who habitually rearfoot strike had approximately twice the rate of repetitive stress injuries than individuals who habitually forefoot strike. Traumatic injury rates were not significantly different between the two groups. A generalized linear model showed that strike type, sex, race distance, and average miles per week each correlate significantly (P < 0.01) with repetitive injury rates. Competitive cross-country runners on a college team incur high injury rates, but runners who habitually rearfoot strike have significantly higher rates of repetitive stress injury than those who mostly forefoot strike. This study does not test the causal bases for this general difference. One hypothesis, which requires further research, is that the absence of a marked impact peak in the ground reaction force during a forefoot strike compared with a rearfoot strike may contribute to lower rates of injuries in habitual forefoot strikers.

Patellofemoral joint stress during running with alterations in foot strike pattern.

PubMed

Vannatta, Charles Nathan; Kernozek, Thomas W

2015-05-01

This study aimed to quantify differences in patellofemoral joint stress that may occur when healthy runners alter their foot strike pattern from their habitual rearfoot strike to a forefoot strike to gain insight on the potential etiology and treatment methods of patellofemoral pain. Sixteen healthy female runners completed 20 running trials in a controlled laboratory setting under rearfoot strike and forefoot strike conditions. Kinetic and kinematic data were used to drive a static optimization technique to estimate individual muscle forces to input into a model of the patellofemoral joint to estimate joint stress during running. Peak patellofemoral joint stress and the stress-time integral over stance phase decreased by 27% and 12%, respectively, in the forefoot strike condition (P < 0.001). Peak vertical ground reaction force increased slightly in the forefoot strike condition (P < 0.001). Peak quadriceps force and average hamstring force decreased, whereas gastrocnemius and soleus muscle forces increased when running with a forefoot strike (P < 0.05). Knee flexion angle at initial contact increased (P < 0.001), total knee excursion decreased (P < 0.001), and no change occurred in peak knee flexion angle (P = 0.238). Step length did not change between conditions (P = 0.375), but the leading leg landed with the foot positioned with a horizontal distance closer to the hip at initial contact in the forefoot strike condition (P < 0.001). Altering one's strike pattern to a forefoot strike results in consistent reductions in patellofemoral joint stress independent of changes in step length. Thus, implementation of forefoot strike training programs may be warranted in the treatment of runners with patellofemoral pain. However, it is suggested that the transition to a forefoot strike pattern should be completed in a graduated manner.

Effect of public transport strikes on air pollution levels in Barcelona (Spain).

PubMed

Basagaña, Xavier; Triguero-Mas, Margarita; Agis, David; Pérez, Noemí; Reche, Cristina; Alastuey, Andrés; Querol, Xavier

2018-01-01

Public transport strikes can lead to an increase of the number of private vehicle trips, which in turn can increase air pollution levels. We aimed to estimate the change in air pollution concentrations during public transport strikes in the city of Barcelona (Spain). Data on strikes of the metro, train or bus systems were collected from government records (2005-2016). We collected daily concentrations of NOx; particulate matter with an aerodynamic diameter smaller than 10μm (PM10), 2.5μm (PM2.5), and 1μm (PM1); particle number concentration (N); black carbon (BC) and CO from research and official monitoring stations. We fitted linear regression models for each pollutant with the strike indicator as an independent variable, and models were adjusted for day of the week, month, year, and holiday periods. During the study period, there were 208days affected by a strike of the metro (28), train (106) or bus (91) systems. Half of the strikes were partial, most of them were single-day strikes, there was little overlap between strikes of the different transport systems, and all strikes had to comply with mandatory minimal services. When pooling all types of strikes, NOx and BC showed higher levels during strike days in comparison with non-strike days (increase between 4.1% and 7.7%, with higher increases for NO). The increases in these concentrations were more evident during full day and multiday metro strikes. In conclusion, alterations in public transport have consequences on air quality. This highlights the importance of public transport in reducing air pollution concentrations in cities. Copyright © 2017 Elsevier B.V. All rights reserved.

Distributed Computing for the Pierre Auger Observatory

NASA Astrophysics Data System (ADS)

Chudoba, J.

2015-12-01

Pierre Auger Observatory operates the largest system of detectors for ultra-high energy cosmic ray measurements. Comparison of theoretical models of interactions with recorded data requires thousands of computing cores for Monte Carlo simulations. Since 2007 distributed resources connected via EGI grid are successfully used. The first and the second versions of production system based on bash scripts and MySQL database were able to submit jobs to all reliable sites supporting Virtual Organization auger. For many years VO auger belongs to top ten of EGI users based on the total used computing time. Migration of the production system to DIRAC interware started in 2014. Pilot jobs improve efficiency of computing jobs and eliminate problems with small and less reliable sites used for the bulk production. The new system has also possibility to use available resources in clouds. Dirac File Catalog replaced LFC for new files, which are organized in datasets defined via metadata. CVMFS is used for software distribution since 2014. In the presentation we give a comparison of the old and the new production system and report the experience on migrating to the new system.

Simple proteomics data analysis in the object-oriented PowerShell.

PubMed

Mohammed, Yassene; Palmblad, Magnus

2013-01-01

Scripting languages such as Perl and Python are appreciated for solving simple, everyday tasks in bioinformatics. A more recent, object-oriented command shell and scripting language, Windows PowerShell, has many attractive features: an object-oriented interactive command line, fluent navigation and manipulation of XML files, ability to consume Web services from the command line, consistent syntax and grammar, rich regular expressions, and advanced output formatting. The key difference between classical command shells and scripting languages, such as bash, and object-oriented ones, such as PowerShell, is that in the latter the result of a command is a structured object with inherited properties and methods rather than a simple stream of characters. Conveniently, PowerShell is included in all new releases of Microsoft Windows and therefore already installed on most computers in classrooms and teaching labs. In this chapter we demonstrate how PowerShell in particular allows easy interaction with mass spectrometry data in XML formats, connection to Web services for tools such as BLAST, and presentation of results as formatted text or graphics. These features make PowerShell much more than "yet another scripting language."

Microseismic event location using global optimization algorithms: An integrated and automated workflow

NASA Astrophysics Data System (ADS)

Lagos, Soledad R.; Velis, Danilo R.

2018-02-01

We perform the location of microseismic events generated in hydraulic fracturing monitoring scenarios using two global optimization techniques: Very Fast Simulated Annealing (VFSA) and Particle Swarm Optimization (PSO), and compare them against the classical grid search (GS). To this end, we present an integrated and optimized workflow that concatenates into an automated bash script the different steps that lead to the microseismic events location from raw 3C data. First, we carry out the automatic detection, denoising and identification of the P- and S-waves. Secondly, we estimate their corresponding backazimuths using polarization information, and propose a simple energy-based criterion to automatically decide which is the most reliable estimate. Finally, after taking proper care of the size of the search space using the backazimuth information, we perform the location using the aforementioned algorithms for 2D and 3D usual scenarios of hydraulic fracturing processes. We assess the impact of restricting the search space and show the advantages of using either VFSA or PSO over GS to attain significant speed-ups.

getimages: Background derivation and image flattening method

NASA Astrophysics Data System (ADS)

Men'shchikov, Alexander

2017-05-01

getimages performs background derivation and image flattening for high-resolution images obtained with space observatories. It is based on median filtering with sliding windows corresponding to a range of spatial scales from the observational beam size up to a maximum structure width X. The latter is a single free parameter of getimages that can be evaluated manually from the observed image. The median filtering algorithm provides a background image for structures of all widths below X. The same median filtering procedure applied to an image of standard deviations derived from a background-subtracted image results in a flattening image. Finally, a flattened image is computed by dividing the background-subtracted by the flattening image. Standard deviations in the flattened image are now uniform outside sources and filaments. Detecting structures in such radically simplified images results in much cleaner extractions that are more complete and reliable. getimages also reduces various observational and map-making artifacts and equalizes noise levels between independent tiles of mosaicked images. The code (a Bash script) uses FORTRAN utilities from getsources (ascl:1507.014), which must be installed.

Identification of an Astrovirus Commonly Infecting Laboratory Mice in the US and Japan

PubMed Central

Ng, Terry Fei Fan; Kondov, Nikola O.; Hayashimoto, Nobuhito; Uchida, Ritsuki; Cha, Yunhee; Beyer, Ashley I.; Wong, Walt; Pesavento, Patricia A.; Suemizu, Hiroshi; Muench, Marcus O.; Delwart, Eric

2013-01-01

Mice (Mus musculus) are the most commonly used laboratory animals. Viral metagenomics on tissues of immunodeficient mice revealed sequences of a novel mammalian astrovirus. Using PCR, we screened mice from 4 breeders, 4 pharmaceutical companies, 14 research institutes and 30 universities in the US and Japan. Mice from one US breeder tested positive while none from Japanese breeders were positive for MuAstV. Mice in over half of the universities (19/30), institutes (7/14) and pharmaceutical animal facilities (2/4) investigated revealed the presence of MuAstV. Nine mice strains tested positive including both immunodeficient strains (NSG, NOD-SCID, NSG-3GS, C57BL6-Timp-3 −/−, and uPA-NOG) and immunocompetent strains (B6J, ICR, Bash2, BALB/c). Our data indicates that MuAstV has a wide geographical, institutional and host strain distribution. Comparison of the MuAstV RdRp sequences showed numerous mutations indicating ongoing viral divergence in different facilities. This study demonstrates the need for metagenomic screening of laboratory animals to identify adventitious infections that may affect experimental outcomes. PMID:23825590

Foot strike patterns of recreational and sub-elite runners in a long-distance road race.

PubMed

Larson, Peter; Higgins, Erin; Kaminski, Justin; Decker, Tamara; Preble, Janine; Lyons, Daniela; McIntyre, Kevin; Normile, Adam

2011-12-01

Although the biomechanical properties of the various types of running foot strike (rearfoot, midfoot, and forefoot) have been studied extensively in the laboratory, only a few studies have attempted to quantify the frequency of running foot strike variants among runners in competitive road races. We classified the left and right foot strike patterns of 936 distance runners, most of whom would be considered of recreational or sub-elite ability, at the 10 km point of a half-marathon/marathon road race. We classified 88.9% of runners at the 10 km point as rearfoot strikers, 3.4% as midfoot strikers, 1.8% as forefoot strikers, and 5.9% of runners exhibited discrete foot strike asymmetry. Rearfoot striking was more common among our sample of mostly recreational distance runners than has been previously reported for samples of faster runners. We also compared foot strike patterns of 286 individual marathon runners between the 10 km and 32 km race locations and observed increased frequency of rearfoot striking at 32 km. A large percentage of runners switched from midfoot and forefoot foot strikes at 10 km to rearfoot strikes at 32 km. The frequency of discrete foot strike asymmetry declined from the 10 km to the 32 km location. Among marathon runners, we found no significant relationship between foot strike patterns and race times.

Impact of a Cosmic Body into Earth's Ocean and the Generation of Large Tsunami Waves: Insight from Numerical Modeling

NASA Astrophysics Data System (ADS)

Wünnemann, K.; Collins, G. S.; Weiss, R.

2010-12-01

The strike of a cosmic body into a marine environment differs in several respects from impact on land. Oceans cover approximately 70% of the Earth's surface, implying not only that oceanic impact is a very likely scenario for future impacts but also that most impacts in Earth's history must have happened in marine environments. Therefore, the study of oceanic impact is imperative in two respects: (1) to quantify the hazard posed by future oceanic impacts, including the potential threat of large impact-generated tsunami-like waves, and (2) to reconstruct Earth's impact record by accounting for the large number of potentially undiscovered crater structures in the ocean crust. Reconstruction of the impact record is of crucial importance both for assessing the frequency of collision events in the past and for better predicting the probability of future impact. We summarize the advances in the study of oceanic impact over the last decades and focus in particular on how numerical models have improved our understanding of cratering in the oceanic environment and the generation of waves by impact. We focus on insight gleaned from numerical modeling studies into the deceleration of the projectile by the water, cratering of the ocean floor, the late stage modification of the crater due to gravitational collapse, and water resurge. Furthermore, we discuss the generation and propagation of large tsunami-like waves as a result of a strike of a cosmic body in marine environments.

Household Adaptive Behavior in Response to Coastal Flood Risk and External Stressors

NASA Astrophysics Data System (ADS)

Buchanan, M. K.

2017-12-01

Approximately forty percent of the world's population sits along ocean coastlines. This urban exposure to flooding is increasing due to population growth and sea level rise resulting from anthropogenic climate change. Recent research improving the characterization of physical hazards from climate change on the coastal zone has helped cities assess their risks. This work includes improving our understanding of the rate and magnitude of sea level rise, the change in distribution of tropical cyclones, and the resulting frequency and severity of flooding on global to local scales. However, the ability of settlements to cope or thrive under changing climate conditions will likely depend on the cooperation and initiative of households, regardless of any governmental efforts to reduce risk. Understanding individuals' likely responses to changing coastal hazards is thus critical for decision-makers to plan for a sustainable future. Individuals may be motivated not only by information regarding emerging flood hazards, but also by cognitive and contextual factors. For governments to develop effective adaptation policies, it is important to understand what factors tend to motivate household adaptation. We apply principles from economics and psychology to investigate how people respond to various existing adaptation options and policies, using a household survey with experiments in New York City neighborhoods affected by Hurricane Sandy. We investigate a comprehensive set of factors that may influence household adaptive behavior. A striking 64% of homeowners and 83% of renters intend to relocate among different plausible future conditions, such as frequent nuisance flooding and the adaptation of peers. This amount is substantial considering the political sensitivity of `retreat' and the lack of regional and federal preparation for large-scale climate-induced migration.

Colorado Late Cenozoic Fault and Fold Database and Internet Map Server: User-friendly technology for complex information

USGS Publications Warehouse

Morgan, K.S.; Pattyn, G.J.; Morgan, M.L.

2005-01-01

Internet mapping applications for geologic data allow simultaneous data delivery and collection, enabling quick data modification while efficiently supplying the end user with information. Utilizing Web-based technologies, the Colorado Geological Survey's Colorado Late Cenozoic Fault and Fold Database was transformed from a monothematic, nonspatial Microsoft Access database into a complex information set incorporating multiple data sources. The resulting user-friendly format supports easy analysis and browsing. The core of the application is the Microsoft Access database, which contains information compiled from available literature about faults and folds that are known or suspected to have moved during the late Cenozoic. The database contains nonspatial fields such as structure type, age, and rate of movement. Geographic locations of the fault and fold traces were compiled from previous studies at 1:250,000 scale to form a spatial database containing information such as length and strike. Integration of the two databases allowed both spatial and nonspatial information to be presented on the Internet as a single dataset (http://geosurvey.state.co.us/pubs/ceno/). The user-friendly interface enables users to view and query the data in an integrated manner, thus providing multiple ways to locate desired information. Retaining the digital data format also allows continuous data updating and quick delivery of newly acquired information. This dataset is a valuable resource to anyone interested in earthquake hazards and the activity of faults and folds in Colorado. Additional geologic hazard layers and imagery may aid in decision support and hazard evaluation. The up-to-date and customizable maps are invaluable tools for researchers or the public.

Active tectonics of the Seattle fault and central Puget sound, Washington - Implications for earthquake hazards

USGS Publications Warehouse

Johnson, S.Y.; Dadisman, S.V.; Childs, J. R.; Stanley, W.D.

1999-01-01

We use an extensive network of marine high-resolution and conventional industry seismic-reflection data to constrain the location, shallow structure, and displacement rates of the Seattle fault zone and crosscutting high-angle faults in the Puget Lowland of western Washington. Analysis of seismic profiles extending 50 km across the Puget Lowland from Lake Washington to Hood Canal indicates that the west-trending Seattle fault comprises a broad (4-6 km) zone of three or more south-dipping reverse faults. Quaternary sediment has been folded and faulted along all faults in the zone but is clearly most pronounced along fault A, the northernmost fault, which forms the boundary between the Seattle uplift and Seattle basin. Analysis of growth strata deposited across fault A indicate minimum Quaternary slip rates of about 0.6 mm/yr. Slip rates across the entire zone are estimated to be 0.7-1.1 mm/yr. The Seattle fault is cut into two main segments by an active, north-trending, high-angle, strike-slip fault zone with cumulative dextral displacement of about 2.4 km. Faults in this zone truncate and warp reflections in Tertiary and Quaternary strata and locally coincide with bathymetric lineaments. Cumulative slip rates on these faults may exceed 0.2 mm/yr. Assuming no other crosscutting faults, this north-trending fault zone divides the Seattle fault into 30-40-km-long western and eastern segments. Although this geometry could limit the area ruptured in some Seattle fault earthquakes, a large event ca. A.D. 900 appears to have involved both segments. Regional seismic-hazard assessments must (1) incorporate new information on fault length, geometry, and displacement rates on the Seattle fault, and (2) consider the hazard presented by the previously unrecognized, north-trending fault zone.

How a Country-Wide Seismological Network Can Improve Understanding of Seismicity and Seismic Hazard -- The Example of Bhutan

NASA Astrophysics Data System (ADS)

Hetényi, G.; Diehl, T.; Singer, J.; Kissling, E. H.; Clinton, J. F.; Wiemer, S.

2015-12-01

The Eastern Himalayas are home to a seemingly complex seismo-tectonic evolution. The rate of instrumental seismicity is lower than the average along the orogen, there is no record of large historical events, but both paleoseismology and GPS studies point to potentially large (M>8) earthquakes. Due to the lack of a permanent seismic monitoring system in the area, our current level of understanding is inappropriate to create a reliable quantitative seismic hazard model for the region. Existing maps are based on questionable hypotheses and show major inconsistencies when compared to each other. Here we present results on national and regional scales from a 38-station broadband seismological network we operated for almost 2 years in the Kingdom of Bhutan. A thorough, state-of-the-art analysis of local and regional earthquakes builds a comprehensive catalogue that reveals significantly (2-to-3 orders of magnitude) more events than detected from global networks. The seismotectonic analysis reveals new patterns of seismic activity as well as striking differences over relatively short distances within the Himalayas, only partly explained by surface observations such as geology. We compare a priori and a posteriori (BMC) magnitude of completeness maps and show that our network was able to detect all felt events during its operation. Some of these events could be felt at surprisingly large distances. Based on our experiment and experience, we draft the pillars on which a permanent seismological observatory for Bhutan could be constructed. Such a continuous monitoring system of seismic activity could then lead to a reliable quantitative seismic hazard model for Bhutan and surrounding regions, and serve as a base to improve building codes and general preparedness.

Far field tsunami simulations of the 1755 Lisbon earthquake: Implications for tsunami hazard to the U.S. East Coast and the Caribbean

USGS Publications Warehouse

Barkan, R.; ten Brink, Uri S.; Lin, J.

2009-01-01

The great Lisbon earthquake of November 1st, 1755 with an estimated moment magnitude of 8.5-9.0 was the most destructive earthquake in European history. The associated tsunami run-up was reported to have reached 5-15??m along the Portuguese and Moroccan coasts and the run-up was significant at the Azores and Madeira Island. Run-up reports from a trans-oceanic tsunami were documented in the Caribbean, Brazil and Newfoundland (Canada). No reports were documented along the U.S. East Coast. Many attempts have been made to characterize the 1755 Lisbon earthquake source using geophysical surveys and modeling the near-field earthquake intensity and tsunami effects. Studying far field effects, as presented in this paper, is advantageous in establishing constraints on source location and strike orientation because trans-oceanic tsunamis are less influenced by near source bathymetry and are unaffected by triggered submarine landslides at the source. Source location, fault orientation and bathymetry are the main elements governing transatlantic tsunami propagation to sites along the U.S. East Coast, much more than distance from the source and continental shelf width. Results of our far and near-field tsunami simulations based on relative amplitude comparison limit the earthquake source area to a region located south of the Gorringe Bank in the center of the Horseshoe Plain. This is in contrast with previously suggested sources such as Marqu??s de Pombal Fault, and Gulf of C??diz Fault, which are farther east of the Horseshoe Plain. The earthquake was likely to be a thrust event on a fault striking ~ 345?? and dipping to the ENE as opposed to the suggested earthquake source of the Gorringe Bank Fault, which trends NE-SW. Gorringe Bank, the Madeira-Tore Rise (MTR), and the Azores appear to have acted as topographic scatterers for tsunami energy, shielding most of the U.S. East Coast from the 1755 Lisbon tsunami. Additional simulations to assess tsunami hazard to the U.S. East Coast from possible future earthquakes along the Azores-Iberia plate boundary indicate that sources west of the MTR and in the Gulf of Cadiz may affect the southeastern coast of the U.S. The Azores-Iberia plate boundary west of the MTR is characterized by strike-slip faults, not thrusts, but the Gulf of Cadiz may have thrust faults. Southern Florida seems to be at risk from sources located east of MTR and South of the Gorringe Bank, but it is mostly shielded by the Bahamas. Higher resolution near-shore bathymetry along the U.S. East Coast and the Caribbean as well as a detailed study of potential tsunami sources in the central west part of the Horseshoe Plain are necessary to verify our simulation results. ?? 2008 Elsevier B.V.

Geo-electrical and geological strikes of the Mount Lamongan geothermal area, East Java, Indonesia – preliminary results

NASA Astrophysics Data System (ADS)

Nugraheni, L. R.; Niasari, S. W.; Nukman, M.

2018-04-01

Geothermal manifestations located in the Tiris, Mount Lamongan, Probolinggo, consist of warm springs. These warm springs have temperature from 35° until 45°C. Tiris fault has NW-SE dominant orientation, similar to some lineaments of maars and cinder cones around Mount Lamongan. The Mount Lamongan geothermal area is situated between Bromo and Argapura volcanoes. This study aims to map the geo-electrical and geological strikes in the study area. Phase tensor analysis has been performed in this study to determine geo-electrical strike of study area. Geological field campaign has been conducted to measure geological strikes. Then, orientation of geo-electrical strike was compared to geological strike. The result presents that the regional geological strike of study area is NW-SE while the orientation of geo-electrical strike is N-S.

75 FR 1442 - Self-Regulatory Organizations; Notice of Filing and Immediate Effectiveness of a Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-11

... OMX PHLX, Inc. To Amend the $1 Strike Program To Allow Low-Strike LEAPS January 4, 2010. Pursuant to... 1012 (Series of Options Open for Trading) to expand the Exchange's $1 Strike Price Program (``Program'' or ``$1 Strike Program'') \\3\\ to allow listing long-term option series (``LEAPS'') \\4\\ in $1 strike...

75 FR 14229 - Self-Regulatory Organizations; Notice of Filing and Immediate Effectiveness of a Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-24

...) of the Securities Exchange Act of 1934 (``Act'')\\1\\, and Rule 19b-4\\2\\ thereunder, notice is hereby... Price Program (``$1 Strike Program'').\\4\\ \\3\\ The $0.50 Strike Program was initiated in an immediately... $4 strikes for classes that participate in both the $0.50 Strike Program and the $1 Strike Program...

Implications of Incessant Strike Actions on the Implementation of Technical Education Programme in Nigeria

ERIC Educational Resources Information Center

Adavbiele, J. A.

2015-01-01

This paper was designed to x-ray the implications of incessant strike actions on the implementation of Technical education programme in Nigeria. The paper took an exploratory view on the concept of strike actions in Nigeria with particular references on notable strike actions that have occurred in Nigeria. The types of strike were explained and…

Relationship between foot strike pattern, running speed, and footwear condition in recreational distance runners.

PubMed

Cheung, Roy T H; Wong, Rodney Y L; Chung, Tim K W; Choi, R T; Leung, Wendy W Y; Shek, Diana H Y

2017-06-01

Compared to competitive runners, recreational runners appear to be more prone to injuries, which have been associated with foot strike patterns. Surprisingly, only few studies had examined the foot strike patterns outside laboratories. Therefore, this study compared the foot strike patterns in recreational runners at outdoor tracks with previously reported data. We also investigated the relationship between foot strike pattern, speed, and footwear in this cohort. Among 434 recreational runners analysed, 89.6% of them landed with rearfoot strike (RFS). Only 6.9 and 3.5% landed with midfoot and forefoot, respectively. A significant shift towards non-RFS was observed in our cohort, when compared with previously reported data. When speed increased by 1 m/s, the odds of having forefoot strike and midfoot strike relative to RFS increased by 2.3 times and 2.6 times, respectively. Runners were 9.2 times more likely to run with a forefoot strike in minimalists compared to regular running shoes, although 70% of runners in minimalists continued to use a RFS. These findings suggest that foot strike pattern may differ across running conditions and runners should consider these factors in order to mitigate potential injury.

Debunking the viper's strike: harmless snakes kill a common assumption.

PubMed

Penning, David A; Sawvel, Baxter; Moon, Brad R

2016-03-01

To survive, organisms must avoid predation and acquire nutrients and energy. Sensory systems must correctly differentiate between potential predators and prey, and elicit behaviours that adjust distances accordingly. For snakes, strikes can serve both purposes. Vipers are thought to have the fastest strikes among snakes. However, strike performance has been measured in very few species, especially non-vipers. We measured defensive strike performance in harmless Texas ratsnakes and two species of vipers, western cottonmouths and western diamond-backed rattlesnakes, using high-speed video recordings. We show that ratsnake strike performance matches or exceeds that of vipers. In contrast with the literature over the past century, vipers do not represent the pinnacle of strike performance in snakes. Both harmless and venomous snakes can strike with very high accelerations that have two key consequences: the accelerations exceed values that can cause loss of consciousness in other animals, such as the accelerations experienced by jet pilots during extreme manoeuvres, and they make the strikes faster than the sensory and motor responses of mammalian prey and predators. Both harmless and venomous snakes can strike faster than the blink of an eye and often reach a target before it can move. © 2016 The Author(s).

Parkinsonian abnormality of foot strike: a phenomenon of ageing and/or one responsive to levodopa therapy?

PubMed Central

Hughes, J R; Bowes, S G; Leeman, A L; O'Neill, C J; Deshmukh, A A; Nicholson, P W; Dobbs, S M; Dobbs, R J

1990-01-01

1. Normally during walking, the heel strikes the ground before the forefoot. Abnormalities of foot strike in idiopathic Parkinson's disease may be amenable to therapy: objective measurements may reveal response which is not clinically apparent. Occult changes in foot strike leading to instability may parallel the normal, age-related loss of striatal dopamine. 2. The nature of foot strike was studied using pedobarography in 160 healthy volunteers, aged 15 to 91 years. Although 16% of strikes were made simultaneously by heel and forefoot, there were no instances of the forefoot preceding the heel. No significant effect of age on an index of normality of foot strikes was detected (P greater than 0.3). 3. The effect on foot strike of substituting placebo for a morning dose of a levodopa/carbidopa combination was studied in a double-blind, cross-over trial in 14 patients, aged 64 to 88 years, with no overt fluctuations in control of their idiopathic Parkinson's disease in relation to dosing. On placebo treatment there was a highly significant (P = 0.004) reduction in the number of more normal strikes, i.e. heel strikes plus simultaneous heel and forefoot strikes. The effect appeared unrelated to the corresponding difference between active and placebo treatments in plasma concentration of levodopa or a metabolite of long half-time, 3-O-methyldopa (3OMD). However, it correlated negatively (P less than 0.05) with the mean of the 3OMD concentrations. 4. It appears that some abnormalities of foot strike due to Parkinson's disease are reversible. Employing test conditions, designed to provoke abnormalities of foot strike, might be useful in screening for pre-clinical Parkinson's disease. PMID:2306409

The effect of hand dominance on martial arts strikes.

PubMed

Neto, Osmar Pinto; Silva, Jansen Henrique; Marzullo, Ana Carolina de Miranda; Bolander, Richard P; Bir, Cynthia A

2012-08-01

The main goal of this study was to compare dominant and non-dominant martial arts palm strikes under different circumstances that usually happen during martial arts and combative sports applications. Seven highly experienced (10±5 years) right hand dominant Kung Fu practitioners performed strikes with both hands, stances with left or right lead legs, and with the possibility or not of stepping towards the target (moving stance). Peak force was greater for the dominant hand strikes (1593.76±703.45 N vs. 1042.28±374.16 N; p<.001), whereas no difference was found in accuracy between the hands (p=.141). Additionally, peak force was greater for the strikes with moving stance (1448.75±686.01 N vs. 1201.80±547.98 N; p=.002) and left lead leg stance (1378.06±705.48 N vs. 1269.96±547.08 N). Furthermore, the difference in peak force between strikes with moving and stationary stances was statistically significant only for the strikes performed with a left lead leg stance (p=.007). Hand speed was higher for the dominant hand strikes (5.82±1.08 m/s vs. 5.24±0.78 m/s; p=.001) and for the strikes with moving stance (5.79±1.01 m/s vs. 5.29±0.90 m/s; p<.001). The difference in hand speed between right and left hand strikes was only significant for strikes with moving stance. In summary, our results suggest that the stronger palm strike for a right-handed practitioner is a right hand strike on a left lead leg stance moving towards the target. Copyright © 2011 Elsevier B.V. All rights reserved.

THE EFFECT OF HAND DOMINANCE ON MARTIAL ARTS STRIKES

PubMed Central

Neto, Osmar Pinto; Silva, Jansen Henrique; de Miranda Marzullo, Ana Carolina; Bolander, Richard P.; Bir, Cynthia A.

2011-01-01

The main goal of this study was to compare dominant and non-dominant martial arts palm strikes under different circumstances that usually happen during martial arts and combative sports applications. Seven highly experienced (10 ± 5 years) right hand dominant Kung Fu practitioners performed strikes with both hands, stances with left or right lead legs, and with the possibility or not of stepping towards the target (moving stance). Peak force was greater for the dominant hand strikes (1593.76 ± 703.45 N vs. 1042.28 ± 374.16 N; p < .001), whereas no difference was found in accuracy between the hands (p = .141). Additionally, peak force was greater for the strikes with moving stance (1448.75 ± 686.01 N vs. 1201.80 ± 547.98 N; p = .002) and left lead leg stance (1378.06 ± 705.48 N vs.1269.96 ± 547.08 N). Furthermore, the difference in peak force between strikes with moving and stationary stances was statistically significant only for the strikes performed with a left lead leg stance (p = .007). Hand speed was higher for the dominant hand strikes (5.82 ± 1.08 m/s vs. 5.24 ± 0.78 m/s; p = 0.001) and for the strikes with moving stance (5.79 ± 1.01 m/s vs. 5.29 ± 0.90 m/s; p < .001). The difference in hand speed between right and left hand strikes was only significant for strikes with moving stance. In summary, our results suggest that the stronger palm strike for a right-handed practitioner is a right hand strike on a left lead leg stance moving towards the target. PMID:22047701

A decade of U.S. Air Force bat strikes

USGS Publications Warehouse

Peurach, Suzanne C.; Dove, Carla J.; Stepko, Laura

2009-01-01

From 1997 through 2007, 821 bat strikes were reported to the U.S. Air Force (USAF) Safety Center by aircraft personnel or ground crew and sent to the National Museum of Natural History, Smithsonian Institution, for identification. Many samples were identified by macroscopic and or microscopic comparisons with bat specimens housed in the museum and augmented during the last 2 years by DNA analysis. Bat remains from USAF strikes during this period were received at the museum from 40 states in the United States and from 20 countries. We confirmed that 46% of the strikes were caused by bats, but we did not identify them further; we identified 5% only to the family or genus level, and 49% to the species level. Fifty-five of the 101 bat-strike samples submitted for DNA analysis have been identified to the species level. Twenty-five bat species have been recorded striking USAF planes worldwide. The Brazilian free-tailed bat (Tadarida brasiliensis; n = 173) is the species most commonly identified in USAF strike impacts, followed by the red bat (Lasiurus borealis; n = 83). Bat strikes peak during the spring and fall, with >57% occurring from August through October; 82% of the reports that included time of strike were recorded between 2100 and 0900 hours. More than 12% of the bat strikes were reported at >300 m above ground level (AGL). Although <1% of the bat-strike reports indicated damage to USAF aircraft, cumulative damage for 1997 through 2007 totaled >$825,000 and >50% of this sum was attributable to 5 bat-strike incidents. Only 5 bats from the 10 most damaging bat strikes were identified to the species level, either because we did not receive remains with the reports or the sample was insufficient for identification.

When Push Comes to Shove: Strikes in Higher Education.

ERIC Educational Resources Information Center

Magney, John

2002-01-01

To provide a better sense of how academic unions handle a strike situation, examines six unions who, between 1996 and 2000, went through strikes. Discusses the key issues and outcomes of the strikes. (EV)

The 10 April 2014 Nicaraguan Crustal Earthquake: Evidence of Complex Deformation of the Central American Volcanic Arc

NASA Astrophysics Data System (ADS)

Suárez, Gerardo; Muñoz, Angélica; Farraz, Isaac A.; Talavera, Emilio; Tenorio, Virginia; Novelo-Casanova, David A.; Sánchez, Antonio

2016-10-01

On 10 April 2014, an M w 6.1 earthquake struck central Nicaragua. The main event and the aftershocks were clearly recorded by the Nicaraguan national seismic network and other regional seismic stations. These crustal earthquakes were strongly felt in central Nicaragua but caused relatively little damage. This is in sharp contrast to the destructive effects of the 1972 earthquake in the capital city of Managua. The differences in damage stem from the fact that the 1972 earthquake occurred on a fault beneath the city; in contrast, the 2014 event lies offshore, under Lake Managua. The distribution of aftershocks of the 2014 event shows two clusters of seismic activity. In the northwestern part of Lake Managua, an alignment of aftershocks suggests a northwest to southeast striking fault, parallel to the volcanic arc. The source mechanism agrees with this right-lateral, strike-slip motion on a plane with the same orientation as the aftershock sequence. For an earthquake of this magnitude, seismic scaling relations between fault length and magnitude predict a sub-surface fault length of approximately 16 km. This length is in good agreement with the extent of the fault defined by the aftershock sequence. A second cluster of aftershocks beneath Apoyeque volcano occurred simultaneously, but spatially separated from the first. There is no clear alignment of the epicenters in this cluster. Nevertheless, the decay of the number of earthquakes beneath Apoyeque as a function of time shows the typical behavior of an aftershock sequence and not of a volcanic swarm. The northeast-southwest striking Tiscapa/Ciudad Jardín and Estadio faults that broke during the 1972 and 1931 Managua earthquakes are orthogonal to the fault where the 10 April earthquake occurred. These orthogonal faults in close geographic proximity show that Central Nicaragua is being deformed in a complex tectonic setting. The Nicaraguan forearc sliver, between the trench and the volcanic arc, moves to the northwest relative to the Caribbean plate at a rate of 14 mm/year. Part of the deformation is apparently accommodated by strain partitioning in the form of bookshelf faulting, on a system of orthogonal faults. The sinistral faults striking northeast-southwest rotate blocks of the Caribbean plate in a clockwise manner. The recent crustal earthquakes in central Nicaragua in 1931, 1972 and 2005 earthquakes took place on these left-lateral faults. The motion of the forearc sliver is also accommodated by a second set of right-lateral, strike-slip faults oriented parallel to the volcanic arc. Faults with this orientation and direction of motion are responsible for the 2014 and possibly the 1955 earthquakes. The presence of this geometry of orthogonal crustal faults highlights the seismic hazard posed by this complex faulting system, not only in the capital city of Managua, but also to the major Nicaraguan cities, which lie close to the volcanic arc.

Lateral Variations of Interplate Coupling along the Mexican Subduction Interface: Relationships with Long-Term Morphology and Fault Zone Mechanical Properties

NASA Astrophysics Data System (ADS)

Rousset, Baptiste; Lasserre, Cécile; Cubas, Nadaya; Graham, Shannon; Radiguet, Mathilde; DeMets, Charles; Socquet, Anne; Campillo, Michel; Kostoglodov, Vladimir; Cabral-Cano, Enrique; Cotte, Nathalie; Walpersdorf, Andrea

2016-10-01

Although patterns of interseismic strain accumulation above subduction zones are now routinely characterised using geodetic measurements, their physical origin, persistency through time, and relationships to seismic hazard and long-term deformation are still debated. Here, we use GPS and morphological observations from southern Mexico to explore potential mechanical links between variations in inter-SSE (in between slow slip events) coupling along the Mexico subduction zone and the long-term topography of the coastal regions from Guerrero to Oaxaca. Inter-SSE coupling solutions for two different geometries of the subduction interface are derived from an inversion of continuous GPS time series corrected from slow slip events. They reveal strong along-strike variations in the shallow coupling (i.e. at depths down to 25 km), with high-coupling zones (coupling >0.7) alternating with low-coupling zones (coupling <0.3). Coupling below the continent is typically strong (>0.7) and transitions to uncoupled, steady slip at a relatively uniform ˜ 175-km inland from the trench. Along-strike variations in the coast-to-trench distances are strongly correlated with the GPS-derived forearc coupling variations. To explore a mechanical explanation for this correlation, we apply Coulomb wedge theory, constrained by local topographic, bathymetric, and subducting-slab slopes. Critical state areas, i.e. areas where the inner subduction wedge deforms, are spatially correlated with transitions at shallow depth between uncoupled and coupled areas of the subduction interface. Two end-member models are considered to explain the correlation between coast-to-trench distances and along-strike variations in the inter-SSE coupling. The first postulates that the inter-SSE elastic strain is partitioned between slip along the subduction interface and homogeneous plastic permanent deformation of the upper plate. In the second, permanent plastic deformation is postulated to depend on frictional transitions along the subduction plate interface. Based on the location and friction values of the critical state areas identified by our Coulomb wedge analysis, we parameterise frictional transitions in plastic-static models of deformation over several seismic cycles. This predicts strong shear dissipation above frictional transitions on the subduction interface. The comparison of modelled surface displacements over a critical zone at a frictional transition and over a stable area with no internal wedge deformation shows differences of long-term uplift consistent with the observed along-strike variations in the coast-to-trench distances. Our work favours a model in which frictional asperities partly control short-term inter-SSE coupling as measured by geodesy and in which those asperities persist through time.

Investigation of possibility of surface rupture derived from PFDHA and calculation of surface displacement based on dislocation

NASA Astrophysics Data System (ADS)

Inoue, N.; Kitada, N.; Irikura, K.

2013-12-01

A probability of surface rupture is important to configure the seismic source, such as area sources or fault models, for a seismic hazard evaluation. In Japan, Takemura (1998) estimated the probability based on the historical earthquake data. Kagawa et al. (2004) evaluated the probability based on a numerical simulation of surface displacements. The estimated probability indicates a sigmoid curve and increases between Mj (the local magnitude defined and calculated by Japan Meteorological Agency) =6.5 and Mj=7.0. The probability of surface rupture is also used in a probabilistic fault displacement analysis (PFDHA). The probability is determined from the collected earthquake catalog, which were classified into two categories: with surface rupture or without surface rupture. The logistic regression is performed for the classified earthquake data. Youngs et al. (2003), Ross and Moss (2011) and Petersen et al. (2011) indicate the logistic curves of the probability of surface rupture by normal, reverse and strike-slip faults, respectively. Takao et al. (2013) shows the logistic curve derived from only Japanese earthquake data. The Japanese probability curve shows the sharply increasing in narrow magnitude range by comparison with other curves. In this study, we estimated the probability of surface rupture applying the logistic analysis to the surface displacement derived from a surface displacement calculation. A source fault was defined in according to the procedure of Kagawa et al. (2004), which determined a seismic moment from a magnitude and estimated the area size of the asperity and the amount of slip. Strike slip and reverse faults were considered as source faults. We applied Wang et al. (2003) for calculations. The surface displacements with defined source faults were calculated by varying the depth of the fault. A threshold value as 5cm of surface displacement was used to evaluate whether a surface rupture reach or do not reach to the surface. We carried out the logistic regression analysis to the calculated displacements, which were classified by the above threshold. The estimated probability curve indicated the similar trend to the result of Takao et al. (2013). The probability of revere faults is larger than that of strike slip faults. On the other hand, PFDHA results show different trends. The probability of reverse faults at higher magnitude is lower than that of strike slip and normal faults. Ross and Moss (2011) suggested that the sediment and/or rock over the fault compress and not reach the displacement to the surface enough. The numerical theory applied in this study cannot deal with a complex initial situation such as topography.

Fracture structures of active Nojima fault, Japan, revealed by borehole televiewer imaging

NASA Astrophysics Data System (ADS)

Nishiwaki, T.; Lin, A.

2017-12-01

Most large intraplate earthquakes occur as slip on mature active faults, any investigation of the seismic faulting process and assessment of seismic hazards require an understanding of the nature of active fault damage zones as seismogenic source. In this study, we focus on the fracture structures of the Nojima Fault (NF) that triggered the 1995 Kobe Mw 7.2 earthquake using ultrasonic borehole televiewer (BHTV) images from a borehole wall. The borehole used in this study was drilled throughout the NF at 1000 m in depth by a science project of Drilling into Fault Damage Zone(DFDZ) in 2016 (Lin, 2016; Miyawaki et al., 2016). In the depth of <230 m of the borehole, the rocks are composed of weak consolidated sandstone and conglomerate of the Plio-Pleistocene Osaka-Group and mudstone and sandstone of the Miocene Kobe Group. The basement rock in the depth of >230 m consist of pre-Neogene granitic rock. Based on the observations of cores and analysis of the BHTV images, the main fault plane was identified at a depth of 529.3 m with a 15 cm thick fault gouge zone and a damage zone of 100 m wide developed in the both sides of the main fault plane. Analysis of the BHTV images shows that the fractures are concentrated in two groups: N45°E (Group-1), parallel to the general trend of the NF, and another strikes N70°E (Group-2), oblique to the fault with an angle of 20°. It is well known that Riedel shear structures are common within strike-slip fault zones. Previous studies show that the NF is a right-lateral strike-slip fault with a minor thrust component, and that the fault damage zone is characterized by Riedel shear structures dominated by Y shears (main faults), R shears and P foliations (Lin, 2001). We interpret that the fractures of Group (1) correspond to Y Riedel fault shears, and those of Group (2) are R shears. Such Riedel shear structures indicate that the NF is a right-lateral strike-slip fault which is activated under a regional stress field oriented to the direction close to east-west, coincident with that inferred from geophysical observations (Tsukahara et al., 2001), seismic inversion results (Katao, 1997) and geological structures (Lin, 2001).Katao et al., 1997. J. Phys. Earth, 45, 105.Lin, 2016. AGU, Fall Meeting.Lin, 2001. J. Struc. Geo., 23, 1167.Miyawaki and Uchida, 2016. AGU, Fall Meeting.Tsukahara et al., 2001. Isl. Arc, 10, 261.

The Cottage Lake Aeromagnetic Lineament: A Possible Onshore Extension of the Southern Whidbey Island Fault, Washington

USGS Publications Warehouse

Blakely, Richard J.; Sherrod, Brian L.; Wells, Ray E.; Weaver, Craig S.; McCormack, David H.; Troost, Kathy G.; Haugerud, Ralph A.

2004-01-01

The northwest-striking southern Whidbey Island fault zone (SWIF) was mapped previously using borehole data and potential-field anomalies on Whidbey Island and marine seismic surveys beneath surrounding waterways. Abrupt subsidence at a coastal marsh on south-central Whidbey Island suggests that the SWIF experienced a MW 6.5 to 7.0 earthquake about 3000 years ago. Southeast of Whidbey Island, a hypothesized southeastward projection of the SWIF would make landfall between the cities of Seattle and Everett. As part of systematic, ongoing studies by the U.S. Geological Survey, University of Washington, and other earth science organizations to evaluate potentially active faults and other earth hazards throughout the Puget Lowland, we test this hypothesis using aeromagnetic, lidar, and borehole data. Linear, northwest-striking magnetic anomalies traversing the mainland region project southeastward toward the communities of Woodinville and Maltby, Washington. All of these magnetic anomalies are low in amplitude and best illuminated in residual magnetic fields. The most prominent of the residual magnetic anomalies extends at least 16 km, lies approximately on strike with the SWIF on Whidbey Island, and passes near Crystal and Cottage Lakes, about 27 km southeast of downtown Everett. In places, this magnetic anomaly is associated with topographic lineaments, but spectral analysis indicates that the source of the anomaly extends to depths greater than 2 km and cannot be explained entirely by topographic effects. The Alderwood #1 oil exploration well located on strike with the Cottage Lake aeromagnetic lineament shows evidence of deformation over a total depth range of 3000 m; some beds within this interval exhibit intense fracturing and shearing, although deformation within the well can only be constrained as post-early Oligocene and pre-Pleistocene. Boreholes acquired as part of a wastewater tunnel project show evidence of soil disturbance at locations where some topographic and aeromagnetic lineaments cross the tunnel alignment. Some of the disturbance is likely tectonic in origin, although other explanations are possible. Some of the soil disturbance demonstrably predates the 15-13 ka Fraser glaciation of the Puget Lowland; other samples have inconclusive ages and may be younger. Subtle scarps in Pleistocene surfaces are visible on high-resolution lidar topography at a number of locations along the Cottage Lake aeromagnetic lineament. Collectively, the scarps are parallel to the trend of the aeromagnetic lineament and extend a total distance of 18 km. In the field, scarps exhibit 1 to 5 m of north-side-up offset. The scarps provide targets for future paleoseismic trenching studies to test the hypothesis that they have a tectonic origin.

Seismicity of the Earth 1900–2010 Himalaya and vicinity

USGS Publications Warehouse

Turner, Bethan; Jenkins, Jennifer; Turner, Rebecca; Parker, Amy; Sinclair, Alison; Davies, Sian; Hayes, Gavin P.; Villaseñor, Antonio; Dart, Rirchard L.; Tarr, Arthur C.; Furlong, Kevin P.; Benz, Harley M.

2013-01-01

Seismicity in the Himalaya region predominantly results from the collision of the India and Eurasia continental plates, which are converging at a relative rate of 40–50 mm/yr. Northward underthrusting of India beneath Eurasia generates numerous earthquakes and consequently makes this area one of the most seismically hazardous regions on Earth. The surface expression of the plate boundary is marked by the foothills of the north-south trending Sulaiman Range in the west, the Indo-Burmese Arc in the east, and the east-west trending Himalaya Front in the north of India. Along the western margin of the India plate, relative motions between India and Eurasia are accommodated by strike-slip, reverse, and oblique-slip faulting resulting in the complex Sulaiman Range fold and thrust belt, and the major translational Chaman Fault in Afghanistan. Beneath the Pamir‒Hindu Kush Mountains of northern Afghanistan, earthquakes occur to depths as great as 200 km as a result of remnant lithospheric subduction. Further north again, the Tian Shan is a seismically active intra-continental mountain belt defined by a series of east-west trending thrust faults thought to be related to the broad footprint of the India-Eurasia collision. Tectonics in northern India are dominated by motion along the Main Frontal Thrust and associated thrust faults of the India-Eurasia plate boundary, which have resulted in a series of large and devastating earthquakes in (and prior to) the 20th century. The Tibetan Plateau to the north of the main plate boundary is a broad region of uplift associated with the India-Eurasia collision, and is cut by a series of generally east-west trending strike-slip faults. These include the Kunlun, Haiyuan, and the Altyn Tagh faults, all of which are left-lateral structures, and the Kara-Koram right-lateral fault. Throughout the plateau, thrust faults accommodate the north-south compressional component of crustal shortening associated with the ongoing collision of India and Eurasia, while strike-slip and normal faults accommodate east-west extension. To the east, The Longmen Shan thrust belt marks the eastern margin of the Tibetan Plateau separating the complex tectonics of the plateau region from the relatively undeformed Sichuan Basin. Further south, the left-lateral Xiangshuihe-Xiaojiiang, right-lateral Red River and right-lateral Sagaing strike-slip fault systems accommodate deformation along the eastern margin of the India plate. Deep earthquakes have also occurred in the Indo-Burmese Arc region, thought to be an expression of eastward-directed subduction of the India plate, though whether subduction is ongoing is still debated.

Conventional Prompt Global Strike and Long Range Ballistic Missiles: Background and Issues

DTIC Science & Technology

2017-02-03

Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues Amy F. Woolf Specialist in Nuclear Weapons Policy...February 3, 2017 Congressional Research Service 7-5700 www.crs.gov R41464 Conventional Prompt Global Strike and Long-Range Ballistic Missiles...Congressional Research Service Summary Conventional prompt global strike (CPGS) weapons would allow the United States to strike targets anywhere

Targeted complement inhibition as a promising strategy for preventing inflammatory complications in hemodialysis

PubMed Central

DeAngelis, Robert A.; Reis, Edimara S.; Ricklin, Daniel; Lambris, John D.

2012-01-01

Hemodialysis is the most common method used to remove waste and hazardous products of metabolism in patients suffering from renal failure. Hundreds of thousands of people with end-stage renal disease undergo hemodialysis treatment in the United States each year. Strikingly, the 5-year survival rate for all dialysis patients is only 35%. Most of the patients succumb to cardiovascular disease that is exacerbated by the chronic induction of inflammation caused by contact of the blood with the dialysis membrane. The complement system, a strong mediator of pro-inflammatory networks, is a key contributor to such biomaterial-induced inflammation. Though only evaluated in experimental ex vivo settings, specific targeting of complement activation during hemodialysis has uncovered valuable information that points towards the therapeutic use of complement inhibitors as means to control the unwelcomed inflammatory responses and consequent pathologies in hemodialysis patients. PMID:22964235

Amplification of postwildfire peak flow by debris

NASA Astrophysics Data System (ADS)

Kean, J. W.; McGuire, L. A.; Rengers, F. K.; Smith, J. B.; Staley, D. M.

2016-08-01

In burned steeplands, the peak depth and discharge of postwildfire runoff can substantially increase from the addition of debris. Yet methods to estimate the increase over water flow are lacking. We quantified the potential amplification of peak stage and discharge using video observations of postwildfire runoff, compiled data on postwildfire peak flow (Qp), and a physically based model. Comparison of flood and debris flow data with similar distributions in drainage area (A) and rainfall intensity (I) showed that the median runoff coefficient (C = Qp/AI) of debris flows is 50 times greater than that of floods. The striking increase in Qp can be explained using a fully predictive model that describes the additional flow resistance caused by the emergence of coarse-grained surge fronts. The model provides estimates of the amplification of peak depth, discharge, and shear stress needed for assessing postwildfire hazards and constraining models of bedrock incision.

Impact Tsunami Calculations: Hydrodynamical Simulations vs. Linear Theory

NASA Technical Reports Server (NTRS)

Korycansky, E.; Asphaug, E.; Ward, S. N.

2003-01-01

Tsunamis generated by the impacts of asteroids and comets into the Earth oceans are widely recognized as a potential catastrophic hazard to the Earth s population. Our general conclusion is that linear theory is a reasonably accurate guide to behavior of tsunamis generated by impactors of moderate size, where the initial transient impact cavity is of moderate depth compared to the ocean depth. This is particularly the case for long wavelength waves that propagate fastest and would reach coastlines first. Such tsunamis would be generated in the open ocean by impactors of 300 meters in diameter, which might be expected to strike the Earth once every few thousand years, on the average. Larger impactors produce cavities deep enough to reach the ocean floor; even here, linear theory is applicable if the starting point is chosen at a later phase in the calculation when the impact crater has slumped back to produce a cavity of moderate depth and slope.

Missing link between the Hayward and Rodgers Creek faults

PubMed Central

Watt, Janet; Ponce, David; Parsons, Tom; Hart, Patrick

2016-01-01

The next major earthquake to strike the ~7 million residents of the San Francisco Bay Area will most likely result from rupture of the Hayward or Rodgers Creek faults. Until now, the relationship between these two faults beneath San Pablo Bay has been a mystery. Detailed subsurface imaging provides definitive evidence of active faulting along the Hayward fault as it traverses San Pablo Bay and bends ~10° to the right toward the Rodgers Creek fault. Integrated geophysical interpretation and kinematic modeling show that the Hayward and Rodgers Creek faults are directly connected at the surface—a geometric relationship that has significant implications for earthquake dynamics and seismic hazard. A direct link enables simultaneous rupture of the Hayward and Rodgers Creek faults, a scenario that could result in a major earthquake (M = 7.4) that would cause extensive damage and loss of life with global economic impact. PMID:27774514

Missing link between the Hayward and Rodgers Creek faults

USGS Publications Warehouse

Watt, Janet; Ponce, David A.; Parsons, Thomas E.; Hart, Patrick E.

2016-01-01

The next major earthquake to strike the ~7 million residents of the San Francisco Bay Area will most likely result from rupture of the Hayward or Rodgers Creek faults. Until now, the relationship between these two faults beneath San Pablo Bay has been a mystery. Detailed subsurface imaging provides definitive evidence of active faulting along the Hayward fault as it traverses San Pablo Bay and bends ~10° to the right toward the Rodgers Creek fault. Integrated geophysical interpretation and kinematic modeling show that the Hayward and Rodgers Creek faults are directly connected at the surface—a geometric relationship that has significant implications for earthquake dynamics and seismic hazard. A direct link enables simultaneous rupture of the Hayward and Rodgers Creek faults, a scenario that could result in a major earthquake (M = 7.4) that would cause extensive damage and loss of life with global economic impact.

Comment on “Historical perspective on seismic hazard to Hispaniola and the northeast Caribbean region” by U. ten Brink et al.

USGS Publications Warehouse

Prentice, Carol S.; Mann, Paul; Peña, Luis R.

2013-01-01

The analysis of historical earthquakes in the northeastern Caribbean by ten Brink et al. [2011, hereafter TB11] addresses the occurrence of large and destructive historical earthquakes associated with the North American-Caribbean plate boundary. One conclusion presented in TB11 is that the recurrence interval for large earthquakes on the left-lateral, strike-slip Septentrional Fault (SF) (Figure 1a) is approximately 300 years. Their Figure 7 shows rupture of the SF across the entire island of Hispaniola in CE 1200, 1542, and 1842. Our comment challenges this model for SF earthquake recurrence because it is inconsistent with our published paleoseismic data that show no large historical earthquake is associated with surface rupture along the SF east of Santiago (Figure 1a)[Prentice et al., 1993; Mann et al., 1998; Prentice et al., 2003].

Static stress change from the 8 October, 2005 M = 7.6 Kashmir earthquake

USGS Publications Warehouse

Parsons, T.; Yeats, R.S.; Yagi, Y.; Hussain, A.

2006-01-01

We calculated static stress changes from the devastating M = 7.6 earthquake that shook Kashmir on 8 October, 2005. We mapped Coulomb stress change on target fault planes oriented by assuming a regional compressional stress regime with greatest principal stress directed orthogonally to the mainshock strike. We tested calculation sensitivity by varying assumed stress orientations, target-fault friction, and depth. Our results showed no impact on the active Salt Range thrust southwest of the rupture. Active faults north of the Main Boundary thrust near Peshawar fall in a calculated stress-decreased zone, as does the Raikot fault zone to the northeast. We calculated increased stress near the rupture where most aftershocks occurred. The greatest increase to seismic hazard is in the Indus-Kohistan seismic zone near the Indus River northwest of the rupture termination, and southeast of the rupture termination near the Kashmir basin.

Earthquake Hazard in the Heart of the Homeland

USGS Publications Warehouse

Gomberg, Joan; Schweig, Eugene

2007-01-01

Evidence that earthquakes threaten the Mississippi, Ohio, and Wabash River valleys of the Central United States abounds. In fact, several of the largest historical earthquakes to strike the continental United States occurred in the winter of 1811-1812 along the New Madrid seismic zone, which stretches from just west of Memphis, Tenn., into southern Illinois. Several times in the past century, moderate earthquakes have been widely felt in the Wabash Valley seismic zone along the southern border of Illinois and Indiana. Throughout the region, between 150 and 200 earthquakes are recorded annually by a network of monitoring instruments, although most are too small to be felt by people. Geologic evidence for prehistoric earthquakes throughout the region has been mounting since the late 1970s. But how significant is the threat? How likely are large earthquakes and, more importantly, what is the chance that the shaking they cause will be damaging?

Amplification of postwildfire peak flow by debris

USGS Publications Warehouse

Kean, Jason W.; McGuire, Luke; Rengers, Francis K.; Smith, Joel B.; Staley, Dennis M.

2016-01-01

In burned steeplands, the peak depth and discharge of postwildfire runoff can substantially increase from the addition of debris. Yet methods to estimate the increase over water flow are lacking. We quantified the potential amplification of peak stage and discharge using video observations of postwildfire runoff, compiled data on postwildfire peak flow (Qp), and a physically based model. Comparison of flood and debris flow data with similar distributions in drainage area (A) and rainfall intensity (I) showed that the median runoff coefficient (C = Qp/AI) of debris flows is 50 times greater than that of floods. The striking increase in Qp can be explained using a fully predictive model that describes the additional flow resistance caused by the emergence of coarse-grained surge fronts. The model provides estimates of the amplification of peak depth, discharge, and shear stress needed for assessing postwildfire hazards and constraining models of bedrock incision.

Stress drops of induced and tectonic earthquakes in the central United States are indistinguishable.

PubMed

Huang, Yihe; Ellsworth, William L; Beroza, Gregory C

2017-08-01

Induced earthquakes currently pose a significant hazard in the central United States, but there is considerable uncertainty about the severity of their ground motions. We measure stress drops of 39 moderate-magnitude induced and tectonic earthquakes in the central United States and eastern North America. Induced earthquakes, more than half of which are shallower than 5 km, show a comparable median stress drop to tectonic earthquakes in the central United States that are dominantly strike-slip but a lower median stress drop than that of tectonic earthquakes in the eastern North America that are dominantly reverse-faulting. This suggests that ground motion prediction equations developed for tectonic earthquakes can be applied to induced earthquakes if the effects of depth and faulting style are properly considered. Our observation leads to the notion that, similar to tectonic earthquakes, induced earthquakes are driven by tectonic stresses.

Stress drops of induced and tectonic earthquakes in the central United States are indistinguishable

PubMed Central

Huang, Yihe; Ellsworth, William L.; Beroza, Gregory C.

2017-01-01

Induced earthquakes currently pose a significant hazard in the central United States, but there is considerable uncertainty about the severity of their ground motions. We measure stress drops of 39 moderate-magnitude induced and tectonic earthquakes in the central United States and eastern North America. Induced earthquakes, more than half of which are shallower than 5 km, show a comparable median stress drop to tectonic earthquakes in the central United States that are dominantly strike-slip but a lower median stress drop than that of tectonic earthquakes in the eastern North America that are dominantly reverse-faulting. This suggests that ground motion prediction equations developed for tectonic earthquakes can be applied to induced earthquakes if the effects of depth and faulting style are properly considered. Our observation leads to the notion that, similar to tectonic earthquakes, induced earthquakes are driven by tectonic stresses. PMID:28782040

Preemptive strikes: Fear, hope, and defensive aggression.

PubMed

Halevy, Nir

2017-02-01

Preemptive strikes are costly and harmful. Existing models of defensive aggression focus narrowly on the role fear plays in motivating preemptive strikes. Theoretically integrating the literatures on conflict, decision making, and emotion, the current research investigated how specific emotions associated with certainty or uncertainty, including fear, anger, disgust, hope, and happiness, influence preemptive strikes. Study 1 demonstrated that hope negatively predicts defensive exits from relationships in choice dilemmas. Studies 2 and 3 experimentally manipulated risk of being attacked in an incentivized, interactive decision making task-the Preemptive Strike Game. Risk of being attacked fueled preemptive strikes; reduced feelings of hope partially mediated this effect in Study 3. Studies 4 and 5 investigated preemptive strikes under uncertainty (rather than risk). In Study 4, reasoning about the factors that make one trustful of others curbed preemptive strikes; cogitating about the factors that underlie discrete emotions, however, did not influence defensive aggression. Study 5 demonstrated that the valence and uncertainty appraisals of incidental emotions interact in shaping preemptive strikes. Specifically, recalling an autobiographical emotional experience that produced hope significantly decreased attack rates relative to fear, happiness, and a control condition. Fear, anger, disgust, and happiness were either unrelated to preemptive strikes or showed inconsistent relationships with preemptive strikes across the 5 studies. These findings shed light on how emotions shape defensive aggression, advance knowledge on strategic choice under risk and uncertainty, and demonstrate hope's positive effects on social interactions and relationships. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Seismic hazard of the Enriquillog-Plantain Garden fault in Haiti inferred from palaeoseismology

USGS Publications Warehouse

Prentice, C.S.; Mann, P.; Crone, A.J.; Gold, R.D.; Hudnut, K.W.; Briggs, R.W.; Koehler, R.D.; Jean, P.

2010-01-01

The Enriquillog-Plantain Garden fault zone is recognized as one of the primary plate-bounding fault systems in Haiti. The strike-slip fault runs adjacent to the city of Port-au-Prince and was initially thought to be the source of the 12 January 2010, M w 7.0 earthquake. Haiti experienced significant earthquakes in 1751 and 1770 (refsA, 3, 4, 5), but the role of the Enriquillog-Plantain Garden fault zone in these earthquakes is poorly known. We use satellite imagery, aerial photography, light detection and ranging (LIDAR) and field investigations to document Quaternary activity on the Enriquillog-Plantain Garden fault. We report late Quaternary, left-lateral offsets of up to 160m, and a set of small offsets ranging from 1.3 to 3.3m that we associate with one of the eighteenth century earthquakes. The size of the small offsets implies that the historical earthquake was larger than M w 7.0, but probably smaller than M w 7.6. We found no significant surface rupture associated with the 2010 earthquake. The lack of surface rupture, coupled with other seismologic, geologic and geodetic observations, suggests that little, if any, accumulated strain was released on the Enriquillog-Plantain Garden fault in the 2010 earthquake. These results confirm that the Enriquillog-Plantain Garden fault remains a significant seismic hazard. ?? 2010 Macmillan Publishers Limited. All rights reserved.

Seismo-Tectonics of the 2014 Chiang Rai, Thailand, Earthquake Sequence

NASA Astrophysics Data System (ADS)

Furlong, K. P.; Pananont, P.; Herman, M. W.; Waldhauser, F.; Pornsopin, P.; Warnitchai, P.; Kosuwan, S.

2016-12-01

On 5 May 2014, a Mw 6.2 strike-slip earthquake struck in the Mae Lao region of Chiang Rai province in Thailand. This earthquake occurred in a region of known faults, but identified as relatively low earthquake hazard, and caused substantial damage and injuries. Detailed field reconnaissance and deployment of a dense, temporary seismometer network allowed details of the damage and its relationship to seismicity to be analyzed. The aftershock sequence associated with this mainshock occurs on two well-defined trends, reflecting the two potential fault planes in earthquake focal mechanisms for the mainshock and the majority of the aftershocks. The damage area was relatively large for an event of this magnitude, but primarily occurs within the primary rupture (aftershock) region or along regional rivers with soils susceptible to liquefaction of other ground failure. Stress modeling combined with the time-series and pattern of aftershock activity lead us to propose that the initial mainshock rupture continued slightly onto its conjugate faults near its northern termination, helping to trigger the distinct pattern of two discrete, conjugate trends of aftershock activity that mirror the kinematics of the mainshock fault mechanism. Although this earthquake occurred in a region of known faults, it cannot be directly linked to a previously mapped structure. This coupled with the substantial damage from the event indicates that there is potentially a higher earthquake hazard in northern and central Thailand than previously recognized.

Climate resiliency: A unique multi-hazard mitigation approach.

PubMed

Baja, Kristin

2016-01-01

Baltimore's unique combination of shocks and stresses cuts across social, economic and environmental factors. Like many other post-industrial cities, over the past several decades, Baltimore has experienced a decline in its population -- resulting in a lower tax base. These trends have had deleterious effects on the city's ability to attend to much needed infrastructure improvements and human and social services. In addition to considerable social and economic issues, the city has begun to experience negative impacts due to climate change. The compounding nature of these trends has put Baltimore, like other post-industrial cities, in the position of having to do more with fewer available resources. Rather than wait for disaster to strike, Baltimore took a proactive approach to planning for shocks and stresses by determining unique ways to pre-emptively plan for and adapt to effects from climate change and incorporating these into the City's All Hazard Mitigation Plan. Since adopting the plan in 2013, Baltimore has been moving forward with various projects aimed at improving systems, enhancing adaptive capacity and building a more resilient and sustainable city. This paper describes the basis for the city's approach and offers a portrait of its efforts in order to broaden foundational knowledge of the emerging ways that cities are recasting the role of planning in light of unprecedented circumstances that demand complex solutions that draw on few resources.

The Effects of Height and Distance on the Force Production and Acceleration in Martial Arts Strikes

PubMed Central

Bolander, Richard P.; Neto, Osmar Pinto; Bir, Cynthia A.

2009-01-01

Almost all cultures have roots in some sort of self defence system and yet there is relatively little research in this area, outside of a sports related environment. This project investigated different applications of strikes from Kung Fu practitioners that have not been addressed before in the literature. Punch and palm strikes were directly compared from different heights and distances, with the use of a load cell, accelerometers, and high speed video. The data indicated that the arm accelerations of both strikes were similar, although the force and resulting acceleration of the target were significantly greater for the palm strikes. Additionally, the relative height at which the strike was delivered was also investigated. The overall conclusion is that the palm strike is a more effective strike for transferring force to an object. It can also be concluded that an attack to the chest would be ideal for maximizing impact force and moving an opponent off balance. Key Points It has been determined that the palm strike is more effective than the punch for developing force and for transferring momentum, most likely the result of a reduced number of rigid links and joints. A strike at head level is less effective than a strike at chest level for developing force and transferring momentum. Distance plays an effect on the overall force and momentum changes, and most likely is dependent on the velocity of the limb and alignment of the bones prior to impact. The teaching of self defence for novices and law enforcement would benefit from including the palm strike as a high priority technique. PMID:24474886

Heel-toe running: A new look at the influence of foot strike pattern on impact force.

PubMed

Mercer, John A; Horsch, Sarah

2015-06-01

It is important to understand the factors that influence the impact force observed during running, since the impact force is likely to be related to overuse injuries. The purpose of this study was to compare the impact force during running when participants were instructed to use different foot strike patterns: obvious heel strike (Obvious-HS), subtle heel strike (Subtle-HS), midfoot strike (Mid-FS), and fore foot strike (Fore-FS) patterns. Participants ( n  = 10, 25 ± 5.7 years, 70.2 ± 12.1 kg, 174.6 ± 7.2 cm) completed four foot strike patterns while running over ground: Obvious-HS, Subtle-HS, Mid-FS, and Fore-FS. Speed was controlled between conditions (random order). Vertical ground reaction forces were recorded (1000 Hz) along with the impact force, peak force, and stance time for analysis. A repeated measures analysis of variance was used to compare each variable across foot strike instructions, with post hoc comparisons contrasting Obvious-HS to each of the other conditions. Impact force was influenced by foot strike instructions, with Obvious-HS being greater than Subtle-HS and Fore-FS ( p  < 0.05) but not different from Mid-FS ( p  > 0.05). The peak force was not influenced by foot strike instructions ( p  > 0.05); stance time was longer during Obvious-HS than during Mid-FS or Fore-FS ( p  < 0.05), but not different from Subtle-HS ( p  > 0.05). The unique observation of this study was that impact force was different when participants were instructed to run with either an Obvious-HS or a Subtle-HS at contact. Both these foot strike patterns would have been considered rear foot strike patterns, suggesting that something other than which specific part of the foot strikes the ground initially influenced impact force.

The October 6, 2008 Mw 6.3 magnitude Damxung earthquake, Yadong-Gulu rift, Tibet, and implications for present-day crustal deformation within Tibet

NASA Astrophysics Data System (ADS)

Wu, Zhong-hai; Ye, Pei-sheng; Barosh, Patrick J.; Wu, Zhen-han

2011-03-01

A Mw 6.3 magnitude earthquake occurred on October 6, 2008 in southern Damxung County within the N-S trending Yangyi graben, which forms the northern section of the Yadong-Gulu rift of south-central Tibet. The earthquake had a maximum intensity of IX at the village of Yangyi (also Yangying) (29°43.3'N; 90°23.6'E) and resulted in 10 deaths and 60 injured in this sparsely populated region. Field observations and focal mechanism solutions show normal fault movement occurred along the NNE-trending western boundary fault of the Yangyi graben, in agreement with the felt epicenter, pattern of the isoseismal contours, and distribution of aftershocks. The earthquake and its tectonic relations were studied in detail to provide data on the seismic hazard to the nearby city of Lhasa. The Damxung earthquake is one of the prominent events along normal and strike-slip faults that occurred widely about Tibet before and after the 2008 Mw 7.9 magnitude Wenchuan earthquake. Analysis of these recent M ⩾ 5.0 earthquake sequences demonstrate a kinematic relation between the normal, strike-slip, and reverse causative fault movements across the region. These earthquakes are found to be linked and the result of eastward extrusion of two large structural blocks of central Tibet. The reverse and oblique-slip surface faulting along the Longmenshan thrust belt at the eastern margin of the Tibetan Plateau causing the Wenchuan earthquake, was the result of eastward directed compression and crustal shortening due to the extrusion. Prior to it, east-west extensional deformation indicated by normal and strike-slip faulting events across central Tibet, had led to a build up of the compression to the east. The subsequent renewal of extensional deformational events in central Tibet appears related to some drag effect due to the crustal shortening of the Wenchuan event. Unraveling the kinematical relation between these earthquake swarms is a very helpful approach for understanding the migration of strong earthquakes across Tibet.

A plate boundary earthquake record from a wetland adjacent to the Alpine fault in New Zealand refines hazard estimates

NASA Astrophysics Data System (ADS)

Cochran, U. A.; Clark, K. J.; Howarth, J. D.; Biasi, G. P.; Langridge, R. M.; Villamor, P.; Berryman, K. R.; Vandergoes, M. J.

2017-04-01

Discovery and investigation of millennial-scale geological records of past large earthquakes improve understanding of earthquake frequency, recurrence behaviour, and likelihood of future rupture of major active faults. Here we present a ∼2000 year-long, seven-event earthquake record from John O'Groats wetland adjacent to the Alpine fault in New Zealand, one of the most active strike-slip faults in the world. We linked this record with the 7000 year-long, 22-event earthquake record from Hokuri Creek (20 km along strike to the north) to refine estimates of earthquake frequency and recurrence behaviour for the South Westland section of the plate boundary fault. Eight cores from John O'Groats wetland revealed a sequence that alternated between organic-dominated and clastic-dominated sediment packages. Transitions from a thick organic unit to a thick clastic unit that were sharp, involved a significant change in depositional environment, and were basin-wide, were interpreted as evidence of past surface-rupturing earthquakes. Radiocarbon dates of short-lived organic fractions either side of these transitions were modelled to provide estimates for earthquake ages. Of the seven events recognised at the John O'Groats site, three post-date the most recent event at Hokuri Creek, two match events at Hokuri Creek, and two events at John O'Groats occurred in a long interval during which the Hokuri Creek site may not have been recording earthquakes clearly. The preferred John O'Groats-Hokuri Creek earthquake record consists of 27 events since ∼6000 BC for which we calculate a mean recurrence interval of 291 ± 23 years, shorter than previously estimated for the South Westland section of the fault and shorter than the current interseismic period. The revised 50-year conditional probability of a surface-rupturing earthquake on this fault section is 29%. The coefficient of variation is estimated at 0.41. We suggest the low recurrence variability is likely to be a feature of other strike-slip plate boundary faults similar to the Alpine fault.

Stress Interactions Between the 1976 Magnitude 7.8 Tangshan Earthquake and Adjacent Fault Systems in Northern China

NASA Astrophysics Data System (ADS)

Zhang, Z.; Lin, J.; Chen, Y. J.

2004-12-01

The 28 July 1976 ML = 7.8 Tangshan earthquake struck a highly populated metropolitan center in northern China and was one of the most devastating earthquakes in modern history. Its occurrence has significantly changed the Coulomb stresses on a complex network of strike-slip, normal, and thrust faults in the region, potentially heightened the odds of future earthquakes on some of these fault segments. We have conducted a detailed analysis of the 3D stress effects of the Tangshan earthquake on its neighboring faults, the relationship between stress transfer and aftershock locations, and the implications for future seismic hazard in the region. Available seismic and geodetic data, although limited, indicate that the Tangshan main shock sequence is composed of complex rupture on 2-3 fault segments. The dominant rupture mode is right-lateral strike-slip on two adjoining sub-segments that strike N5¡aE and N35¡aE, respectively. We calculated that the Tangshan main shock sequence has increased the Coulomb failure stress by more than 1 bar in the vicinity of the Lunanxian district to the east, where the largest aftershock (ML = 7.1) occurred 15 hours after the Tangshan main event. The second largest aftershock (ML = 6.8) occurred on the Ninghe fault to the southwest of the main rupture, in a transitional region between the calculated Coulomb stress increase and decrease. The majority of the ML > 5.0 aftershocks also occurred in areas of calculated Coulomb stress increase. Our analyses further indicate that the Coulomb stress on portions of other fault segments, including the Leting and Lulong fault to the east and Yejito fault to the north, may also have been increased. Thus it is critical to obtain estimates of earthquake repeat times on these and other tectonic faults and to acquire continuous GPS and space geodetic measurements. Investigation of stress interaction and earthquake triggering in northern China is not only highly societal relevant but also important for advancing our understanding of the fundamental characteristics of earthquakes in regions of diffuse continental deformation.

Structure of the active rift zone and margins of the northern Imperial Valley from Salton Seismic Imaging Project (SSIP) data

NASA Astrophysics Data System (ADS)

Livers, A.; Han, L.; Delph, J. R.; White-Gaynor, A. L.; Petit, R.; Hole, J. A.; Stock, J. M.; Fuis, G. S.

2012-12-01

First-arrival refraction data were used to create a seismic velocity model of the upper crust across the actively rifting northern Imperial Valley and its margins. The densely sampled seismic refraction data were acquired by the Salton Seismic Imaging Project (SSIP) , which is investigating rift processes in the northern-most rift segment of the Gulf of California extensional province and earthquake hazards at the southern end of the San Andreas Fault system. A 95-km long seismic line was acquired across the northern Imperial Valley, through the Salton Sea geothermal field, parallel to the five Salton Butte volcanoes and perpendicular to the Brawley Seismic Zone and major strike-slip faults. Nineteen explosive shots were recorded with 100 m seismometer spacing across the valley and with 300-500 m spacing into the adjacent ranges. First-arrival travel times were picked from shot gathers along this line and a seismic velocity model was produced using tomographic inversion. Sedimentary basement and seismic basement in the valley are interpreted to be sediment metamorphosed by the very high heat flow. The velocity model shows that this basement to the west of the Brawley Seismic Zone is at ~4-km depth. The basement shallows to ~2-km depth in the active geothermal field and Salton Buttes volcanic field which locally coincide with the Brawley Seismic Zone. At the eastern edge of the geothermal field, the basement drops off again to ~3.5-km depth. The eastern edge of the valley appears to be fault bounded by the along-strike extension of the Sand Hills Fault, an inactive strike-slip fault. The seismic velocities to the east of the fault correspond to metamorphic rock of the Chocolate Mountains, different from the metamorphosed basement in the valley. The western edge of the valley appears to be fault bounded by the active Superstition Hills Fault. To the west of the valley, >4-km deep valley basement extends to the active Superstition Hills Fault. Basement then shallows westward towards exposures of granitic basement in the Superstition Mountains. The basin between the Superstition Mountains and Coyote Mountains is ~2 km deep.

Gait Retraining From Rearfoot Strike to Forefoot Strike does not change Running Economy.

PubMed

Roper, Jenevieve Lynn; Doerfler, Deborah; Kravitz, Len; Dufek, Janet S; Mermier, Christine

2017-12-01

Gait retraining is a method for management of patellofemoral pain, which is a common ailment among recreational runners. The present study investigated the effects of gait retraining from rearfoot strike to forefoot strike on running economy, heart rate, and respiratory exchange ratio immediately post-retraining and one-month post-retraining in recreational runners with patellofemoral pain. Knee pain was also measured. Sixteen participants (n=16) were randomly placed in the control (n=8) or experimental (n=8) group. A 10-minute treadmill RE test was performed by all subjects. The experimental group performed eight gait retraining running sessions where foot strike pattern was switched from rearfoot strike to forefoot strike, while the control group received no intervention. There were no significant differences for running economy (p=0.26), respiratory exchange ratio (p=0.258), or heart rate (p=0.248) between the groups. Knee pain reported on a visual analog scale was also significantly reduced (p<0.05) as a result of retraining. The present study demonstrates that retraining from rearfoot strike to forefoot strike did not affect running economy up to one-month post-retraining while reducing running-related patellofemoral pain. © Georg Thieme Verlag KG Stuttgart · New York.

Effects of Foot Strike and Step Frequency on Achilles Tendon Stress During Running.

PubMed

Lyght, Michael; Nockerts, Matthew; Kernozek, Thomas W; Ragan, Robert

2016-08-01

Achilles tendon (AT) injuries are common in runners. The AT withstands high magnitudes of stress during running which may contribute to injury. Our purpose was to examine the effects of foot strike pattern and step frequency on AT stress and strain during running utilizing muscle forces based on a musculoskeletal model and subject-specific ultrasound-derived AT cross-sectional area. Nineteen female runners performed running trials under 6 conditions, including rearfoot strike and forefoot strike patterns at their preferred cadence, +5%, and -5% preferred cadence. Rearfoot strike patterns had less peak AT stress (P < .001), strain (P < .001), and strain rate (P < .001) compared with the forefoot strike pattern. A reduction in peak AT stress and strain were exhibited with a +5% preferred step frequency relative to the preferred condition using a rearfoot (P < .001) and forefoot (P=.005) strike pattern. Strain rate was not different (P > .05) between step frequencies within each foot strike condition. Our results suggest that a rearfoot pattern may reduce AT stress, strain, and strain rate. Increases in step frequency of 5% above preferred frequency, regardless of foot strike pattern, may also lower peak AT stress and strain.

Source parameters of the 2014 Ms6.5 Ludian earthquake sequence and their implications on the seismogenic structure

NASA Astrophysics Data System (ADS)

Zheng, Y.

2015-12-01

On August 3, 2014, an Ms6.5 earthquake struck Ludian county, Zhaotong city in Yunnan province, China. Although this earthquake is not very big, it caused abnormal severe damages. Thus, study on the causes of the serious damages of this moderate strong earthquake may help us to evaluate seismic hazards for similar earthquakes. Besides the factors which directly relate to the damages, such as site effects, quality of buildings, seismogenic structures and the characteristics of the mainshock and the aftershocks may also responsible for the seismic hazards. Since focal mechanism solution and centroid depth provide key information of earthquake source properties and tectonic stress field, and the focal depth is one of the most important parameters which control the damages of earthquakes, obtaining precise FMSs and focal depths of the Ludian earthquake sequence may help us to determine the detailed geometric features of the rupture fault and the seismogenic environment. In this work we obtained the FMSs and centroid depths of the Ludian earthquake and its Ms>3.0 aftershocks by the revised CAP method, and further verified some focal depths using the depth phase method. Combining the FMSs of the mainshock and the strong aftershocks, as well as their spatial distributions, and the seismogenic environment of the source region, we can make the following characteristics of the Ludian earthquake sequence and its seismogenic structure: (1) The Ludian earthquake is a left-lateral strike slip earthquake, with magnitude of about Mw6.1. The FMS of nodal plane I is 75o/56o/180o for strike, dip and rake angles, and 165o/90o/34ofor the other nodal plane. (2) The Ludian earthquake is very shallow with the optimum centroid depth of ~3 km, which is consistent with the strong ground shaking and the surface rupture observed by field survey and strengthens the damages of the Ludian earthquake. (3) The Ludian Earthquake should occur on the NNW trend BXF. Because two later aftershocks occurred close to the fault zone of the ZLF, and their FMSs are similar with the characteristics of the ZLF, the shallower part of the ZLF may also rupture during the aftershock duration of the Ludian earthquake. Since the ZLF is much longer than the BXF, the seismic risk of the ZLF may be high and should be required more attention.

A High-Resolution Seismic Survey Across the State Line fault, NV

NASA Astrophysics Data System (ADS)

Beachly, M.; Cox, C. M.; Saldana, S. C.; Snelson, C. M.; Taylor, W. J.; Robins, C.; Davis, R.; Stropky, M.; Phillips, R.; Cothrun, C.

2007-12-01

During the summer of 2007, an investigation of the faulting in Stewart Valley was under taken, located within the central Basin and Range province ~90 km west of Las Vegas, Nevada. The goal of this study was to resolve the seismic hazard potential of the State Line fault, a right-lateral strike-slip fault that runs the length of Stewart Valley. Four seismic reflection lines were acquired, two perpendicular and two parallel to the State Line fault. What is presented is an analysis of the western and eastern seismic lines parallel to the State Line fault. The western line was acquired utilizing a 144-channel geode system with each of the 4.5 Hz vertical geophones set out at 5 m intervals to form a 715 m long profile. The eastern line employed 120 of these geophones in a 595 m long profile. A mini-vibroseis served as the seismic source every ten meters, between geophones. The vibroseis was programmed to produce an 8 s linear sweep from 20-160 Hz. Three sweeps were recorded at each shot location without acquisition filters at a sampling rate of 0.5 ms. The three shot gathers were then stacked at each location to reduce noise. The data collected had minimal noise, although; during the processing of the eastern line a notch filtered was used to remove the 60 Hz noise created by adjacent power line. These lines, acquired parallel to the State Line fault, contain matching features that serve to determine how much lateral displacement the fault has undergone. The amount of the displacement can indicate how active the fault is, and thus, what magnitude of earthquake can be expected in the future. This will in turn contribute to determining the seismic hazard potential for southern Nevada. A preliminary interpretation of the seismic reflection sections indicates an average displacement of about 20 - 38 m with greater displacement in the deeper sections of the image. The shallow depth displacement calculations are consistent with previous work in the area. The State Line fault is believed to be a result of strain partitioning from the San Andreas Fault. By studying this more localized active strike-slip fault system the results of this study can contribute to a model that provides a better understanding of the tectonics in the central Basin and Range.

DOE Office of Scientific and Technical Information (OSTI.GOV)

N. Seth Carpenter; Suzette J. Payne; Annette L. Schafer

We recognize a discrepancy in magnitudes estimated for several Basin and Range, U.S.A. faults. For example, magnitudes predicted for the Wasatch (Utah), Lost River (Idaho), and Lemhi (Idaho) faults from fault segment lengths (L{sub seg}) where lengths are defined between geometrical, structural, and/or behavioral discontinuities assumed to persistently arrest rupture, are consistently less than magnitudes calculated from displacements (D) along these same segments. For self-similarity, empirical relationships (e.g. Wells and Coppersmith, 1994) should predict consistent magnitudes (M) using diverse fault dimension values for a given fault (i.e. M {approx} L{sub seg}, should equal M {approx} D). Typically, the empirical relationshipsmore » are derived from historical earthquake data and parameter values used as input into these relationships are determined from field investigations of paleoearthquakes. A commonly used assumption - grounded in the characteristic-earthquake model of Schwartz and Coppersmith (1984) - is equating L{sub seg} with surface rupture length (SRL). Many large historical events yielded secondary and/or sympathetic faulting (e.g. 1983 Borah Peak, Idaho earthquake) which are included in the measurement of SRL and used to derive empirical relationships. Therefore, calculating magnitude from the M {approx} SRL relationship using L{sub seg} as SRL leads to an underestimation of magnitude and the M {approx} L{sub seg} and M {approx} D discrepancy. Here, we propose an alternative approach to earthquake magnitude estimation involving a relationship between moment magnitude (Mw) and length, where length is L{sub seg} instead of SRL. We analyze seven historical, surface-rupturing, strike-slip and normal faulting earthquakes for which segmentation of the causative fault and displacement data are available and whose rupture included at least one entire fault segment, but not two or more. The preliminary Mw {approx} L{sub seg} results are strikingly consistent with Mw {approx} D calculations using paleoearthquake data for the Wasatch, Lost River, and Lemhi faults, demonstrating self-similarity and implying that the Mw {approx} L{sub seg} relationship should supplant M {approx} SRL relationships currently employed in seismic hazard analyses. The relationship will permit reliable use of L{sub seg} data from field investigations and proper use and weighting of multiple-segment-rupture scenarios in seismic hazard analyses, and eliminate the need to reconcile the Mw {approx} SRL and Mw {approx} D differences in a multiple-parameter relationship for segmented faults.« less

Ground-Motion Variability for a Strike-Slip Earthquake from Broadband Ground-Motion Simulations

NASA Astrophysics Data System (ADS)

Iwaki, A.; Maeda, T.; Morikawa, N.; Fujiwara, H.

2016-12-01

One of the important issues in seismic hazard analysis is the evaluation of ground-motion variability due to the epistemic and aleatory uncertainties in various aspects of ground-motion simulations. This study investigates the within-event ground-motion variability in broadband ground-motion simulations for strike-slip events. We conduct ground-motion simulations for a past event (2000 MW6.6 Tottori earthquake) using a set of characterized source models (e.g. Irikura and Miyake, 2011) considering aleatory variability. Broadband ground motion is computed by a hybrid approach that combines a 3D finite-difference method (> 1 s) and the stochastic Green's function method (< 1 s), using the 3D velocity model J-SHIS v2. We consider various locations of the asperities, which are defined as the regions with large slip and stress drop within the fault, and the rupture nucleation point (hypocenter). Ground motion records at 29 K-NET and KiK-net stations are used to validate our simulations. By comparing the simulated and observed ground motion, we found that the performance of the simulations is acceptable under the condition that the source parameters are poorly constrained. In addition to the observation stations, we set 318 virtual receivers with the spatial intervals of 10 km for statistical analysis of the simulated ground motion. The maximum fault-distance is 160 km. Standard deviation (SD) of the simulated acceleration response spectra (Sa, 5% damped) of RotD50 component (Boore, 2010) is investigated at each receiver. SD from 50 different patterns of asperity locations is generally smaller than 0.15 in terms of log10 (0.34 in natural log). It shows dependence on distance at periods shorter than 1 s; SD increases as the distance decreases. On the other hand, SD from 39 different hypocenter locations is again smaller than 0.15 in log10, and showed azimuthal dependence at long periods; it increases as the rupture directivity parameter Xcosθ(Somerville et al. 1997) increases at periods longer than 1 s. The characteristics of ground-motion variability inferred from simulations can provide information on variability in simulation-based seismic hazard assessment for future earthquakes. We will further investigate the variability in other source parameters; rupture velocity and short-period level.

Developing personal values: trainees' attitudes toward strikes by health care providers.

PubMed

Li, Su-Ting T; Srinivasan, Malathi; Der-Martirosian, Claudia; Kravitz, Richard L; Wilkes, Michael S

2011-05-01

Worldwide, health care providers use strikes and job actions to influence policy. For health care providers, especially physicians, strikes create an ethical tension between an obligation to care for current patients (e.g., to provide care and avoid abandonment) and an obligation to better care for future patients by seeking system improvements (e.g., improvements in safety, to access, and in the composition and strength of the health care workforce). This tension is further intensified when the potential benefit of a strike involves professional self-interest and the potential risk involves patient harm or death. By definition, trainees are still forming their professional identities and values, including their opinions on fair wages, health policy, employee benefits, professionalism, and strikes. In this article, the authors explore these ethical tensions, beginning with a discussion of reactions to a potential 2005 nursing strike at the University of California, Davis, Medical Center. The authors then propose a conceptual model describing factors that may influence health care providers' decisions to strike (including personal ethics, personal agency, and strike-related context). In particular, the authors explore the relationship between training level and attitudes toward taking a job action, such as going on strike. Because trainees' attitudes toward strikes continue to evolve during training, the authors maintain that open discussion around the ethics of health care professionals' strikes and other methods of conflict resolution should be included in medical education to enhance professionalism and systems-based practice training. The authors include sample case vignettes to help initiate these important discussions. Copyright © by the Association of American medical Colleges.

Physicians' strikes--a rejoinder.

PubMed Central

Glick, S M

1985-01-01

The author, a physician, rejects a previous defence of a doctors' strike. There is little justification for strikes in general, still less for doctors' strikes, he claims. Should not doctors rather 'stand above the common herd' and set an example, he asks. Furthermore the whole idea of strikes in which a third and innocent party is deliberately punished in order to apply pressure on someone else is a 'a bizarre ethic indeed' and not to his knowledge justified under any ethical theory. PMID:4078858

Radial arm strike rail

DOEpatents

McKeown, Mark H.; Beason, Steven C.

1991-01-01

The radial arm strike rail assembly is a system for measurement of bearings, directions, and stereophotography for geologic mapping, particularly where magnetic compasses are not appropriate. The radial arm, pivoting around a shaft axis, provides a reference direction determination for geologic mapping and bearing or direction determination. The centerable and levelable pedestal provide a base for the radial arm strike rail and the telescoping camera pedestal. The telescoping feature of the radial arm strike rail allows positioning the end of the rail for strike direction or bearing measurement with a goniometer.

Buried shallow fault slip from the South Napa earthquake revealed by near-field geodesy

PubMed Central

Brooks, Benjamin A.; Minson, Sarah E.; Glennie, Craig L.; Nevitt, Johanna M.; Dawson, Tim; Rubin, Ron; Ericksen, Todd L.; Lockner, David; Hudnut, Kenneth; Langenheim, Victoria; Lutz, Andrew; Mareschal, Maxime; Murray, Jessica; Schwartz, David; Zaccone, Dana

2017-01-01

Earthquake-related fault slip in the upper hundreds of meters of Earth’s surface has remained largely unstudied because of challenges measuring deformation in the near field of a fault rupture. We analyze centimeter-scale accuracy mobile laser scanning (MLS) data of deformed vine rows within ±300 m of the principal surface expression of the M (magnitude) 6.0 2014 South Napa earthquake. Rather than assuming surface displacement equivalence to fault slip, we invert the near-field data with a model that allows for, but does not require, the fault to be buried below the surface. The inversion maps the position on a preexisting fault plane of a slip front that terminates ~3 to 25 m below the surface coseismically and within a few hours postseismically. The lack of surface-breaching fault slip is verified by two trenches. We estimate near-surface slip ranging from ~0.5 to 1.25 m. Surface displacement can underestimate fault slip by as much as 30%. This implies that similar biases could be present in short-term geologic slip rates used in seismic hazard analyses. Along strike and downdip, we find deficits in slip: The along-strike deficit is erased after ~1 month by afterslip. We find no evidence of off-fault deformation and conclude that the downdip shallow slip deficit for this event is likely an artifact. As near-field geodetic data rapidly proliferate and will become commonplace, we suggest that analyses of near-surface fault rupture should also use more sophisticated mechanical models and subsurface geomechanical tests. PMID:28782026

Geophysical setting of the February 21, 2008 Mw 6 Wells earthquake, Nevada, and implications for earthquake hazards

USGS Publications Warehouse

Ponce, David A.; Watt, Janet T.; Bouligand, C.

2011-01-01

We utilize gravity and magnetic methods to investigate the regional geophysical setting of the Wells earthquake. In particular, we delineate major crustal structures that may have played a role in the location of the earthquake and discuss the geometry of a nearby sedimentary basin that may have contributed to observed ground shaking. The February 21, 2008 Mw 6.0 Wells earthquake, centered about 10 km northeast of Wells, Nevada, caused considerable damage to local buildings, especially in the historic old town area. The earthquake occurred on a previously unmapped normal fault and preliminary relocated events indicate a fault plane dipping about 55 degrees to the southeast. The epicenter lies near the intersection of major Basin and Range normal faults along the Ruby Mountains and Snake Mountains, and strike-slip faults in the southern Snake Mountains. Regionally, the Wells earthquake epicenter is aligned with a crustal-scale boundary along the edge of a basement gravity high that correlates to the Ruby Mountains fault zone. The Wells earthquake also occurred near a geophysically defined strike-slip fault that offsets buried plutonic rocks by about 30 km. In addition, a new depth-to-basement map, derived from the inversion of gravity data, indicates that the Wells earthquake and most of its associated aftershock sequence lie below a small oval- to rhomboid-shaped basin, that reaches a depth of about 2 km. Although the basin is of limited areal extent, it could have contributed to increased ground shaking in the vicinity of the city of Wells, Nevada, due to basin amplification of seismic waves.

Buried shallow fault slip from the South Napa earthquake revealed by near-field geodesy.

PubMed

Brooks, Benjamin A; Minson, Sarah E; Glennie, Craig L; Nevitt, Johanna M; Dawson, Tim; Rubin, Ron; Ericksen, Todd L; Lockner, David; Hudnut, Kenneth; Langenheim, Victoria; Lutz, Andrew; Mareschal, Maxime; Murray, Jessica; Schwartz, David; Zaccone, Dana

2017-07-01

Earthquake-related fault slip in the upper hundreds of meters of Earth's surface has remained largely unstudied because of challenges measuring deformation in the near field of a fault rupture. We analyze centimeter-scale accuracy mobile laser scanning (MLS) data of deformed vine rows within ±300 m of the principal surface expression of the M (magnitude) 6.0 2014 South Napa earthquake. Rather than assuming surface displacement equivalence to fault slip, we invert the near-field data with a model that allows for, but does not require, the fault to be buried below the surface. The inversion maps the position on a preexisting fault plane of a slip front that terminates ~3 to 25 m below the surface coseismically and within a few hours postseismically. The lack of surface-breaching fault slip is verified by two trenches. We estimate near-surface slip ranging from ~0.5 to 1.25 m. Surface displacement can underestimate fault slip by as much as 30%. This implies that similar biases could be present in short-term geologic slip rates used in seismic hazard analyses. Along strike and downdip, we find deficits in slip: The along-strike deficit is erased after ~1 month by afterslip. We find no evidence of off-fault deformation and conclude that the downdip shallow slip deficit for this event is likely an artifact. As near-field geodetic data rapidly proliferate and will become commonplace, we suggest that analyses of near-surface fault rupture should also use more sophisticated mechanical models and subsurface geomechanical tests.

Preliminary observations from the 3 January 2017, MW 5.6 Manu, Tripura (India) earthquake

NASA Astrophysics Data System (ADS)

Debbarma, Jimmi; Martin, Stacey S.; Suresh, G.; Ahsan, Aktarul; Gahalaut, Vineet K.

2017-10-01

On 3 January 2017, a MW 5.6 earthquake occurred in Dhalai district in Tripura (India), at 14:39:03 IST (09:09:03 UTC) with an epicentre at 24.018°N ± 4.9 km and 91.964°E ± 4.4 km, and a focal depth of 31 ± 6.0 km. The focal mechanism solution determined after evaluating data from seismological observatories in India indicated a predominantly strike-slip motion on a steeply dipping plane. The estimated focal depth and focal mechanism solution places this earthquake in the Indian plate that lies beneath the overlying Indo-Burmese wedge. As in the 2016 Manipur earthquake, a strong motion record from Shillong, India, appears to suggest site amplification possibly due to topographic effects. In the epicentral region in Tripura, damage assessed from a field survey and from media reports indicated that the macroseismic intensity approached 6-7 EMS with damage also reported in adjacent parts of Bangladesh. A striking feature of this earthquake were the numerous reports of liquefaction that were forthcoming from fluvial locales in the epicentral region in Tripura, and at anomalous distances farther north in Bangladesh. The occurrence of the 2017 Manu earthquake emphasises the hazard posed by intraplate earthquakes in Tripura and in the neighbouring Bengal basin region where records of past earthquakes are scanty or vague, and where the presence of unconsolidated deltaic sediments and poor implementation of building codes pose a significant societal and economic threat during larger earthquakes in the future.

Slip on the San Andreas fault at Parkfield, California, over two earthquake cycles, and the implications for seismic hazard

USGS Publications Warehouse

Murray, J.; Langbein, J.

2006-01-01

Parkfield, California, which experienced M 6.0 earthquakes in 1934, 1966, and 2004, is one of the few locales for which geodetic observations span multiple earthquake cycles. We undertake a comprehensive study of deformation over the most recent earthquake cycle and explore the results in the context of geodetic data collected prior to the 1966 event. Through joint inversion of the variety of Parkfield geodetic measurements (trilateration, two-color laser, and Global Positioning System), including previously unpublished two-color data, we estimate the spatial distribution of slip and slip rate along the San Andreas using a fault geometry based on precisely relocated seismicity. Although the three most recent Parkfield earthquakes appear complementary in their along-strike distributions of slip, they do not produce uniform strain release along strike over multiple seismic cycles. Since the 1934 earthquake, more than 1 m of slip deficit has accumulated on portions of the fault that slipped in the 1966 and 2004 earthquakes, and an average of 2 m of slip deficit exists on the 33 km of the fault southeast of Gold Hill to be released in a future, perhaps larger, earthquake. It appears that the fault is capable of partially releasing stored strain in moderate earthquakes, maintaining a disequilibrium through multiple earthquake cycles. This complicates the application of simple earthquake recurrence models that assume only the strain accumulated since the most recent event is relevant to the size or timing of an upcoming earthquake. Our findings further emphasize that accumulated slip deficit is not sufficient for earthquake nucleation.

Analysis of seismicity in the region off the southeastern Korean Peninsula after the 2011 M9.0 Tohoku-Oki earthquake

NASA Astrophysics Data System (ADS)

Lee, J.; Kim, T. K.; Kim, W.; Hong, T. K.

2017-12-01

The Korean Peninsula is located in a stable intraplate regime with relatively low seismicity. The seismicity in the Korean Peninsula was, however, changed significantly after the 11 March 2011 M9.0 Tohoku-Oki megathrust earthquake. An M5.0 earthquake occurred in 2016 at the region off the southeastern Korean Peninsula. The M5.0 earthquake was the largest event in the region since 1978 when the national seismic monitoring began. Several nuclear power plants are placed near the region. It is requested to understand the seismo-tectonic structures of the region, which may be crucial for mitigation of seismic hazards. Analysis of seismicity may be useful for illumination of fault structures. We investigate the focal mechanism solutions, ambient stress field, and spatial distribution of earthquakes. It is intriguing to note that the number of earthquakes increased since the 2011 Tohoku-Oki earthquake. We refined the hypocenters of 52 events using a velocity-searching hypocentral inversion method (VELHYPO). We determined the focal mechanism solutions of 25 events using a P polarity analysis and long period waveform inversion. The ambient stress field was inferred from the focal mechanism solutions. Strike-slip events occurred dominantly although the paleo-tectonic structures suggest the presence of thrust faults in the region. We observe that the compressional stress field is applied in ENE-WSW, which may be a combination of lateral compressions from the Pacific and Philippine Sea plates. The active strike-slip events and compressional stress field suggest reactivation of paleo-tectonic structures.

Crustal Deformation in the India-Eurasia Collision Zone From 25 Years of GPS Measurements

NASA Astrophysics Data System (ADS)

Zheng, Gang; Wang, Hua; Wright, Tim J.; Lou, Yidong; Zhang, Rui; Zhang, Weixing; Shi, Chuang; Huang, Jinfang; Wei, Na

2017-11-01

The India-Eurasia collision zone is the largest deforming region on the planet; direct measurements of present-day deformation from Global Positioning System (GPS) have the potential to discriminate between competing models of continental tectonics. But the increasing spatial resolution and accuracy of observations have only led to increasingly complex realizations of competing models. Here we present the most complete, accurate, and up-to-date velocity field for India-Eurasia available, comprising 2576 velocities measured during 1991-2015. The core of our velocity field is from the Crustal Movement Observation Network of China-I/II: 27 continuous stations observed since 1999; 56 campaign stations observed annually during 1998-2007; 1000 campaign stations observed in 1999, 2001, 2004, and 2007; 260 continuous stations operating since late 2010; and 2000 campaign stations observed in 2009, 2011, 2013, and 2015. We process these data and combine the solutions in a consistent reference frame with stations from the Global Strain Rate Model compilation, then invert for continuous velocity and strain rate fields. We update geodetic slip rates for the major faults (some vary along strike), and find that those along the major Tibetan strike-slip faults are in good agreement with recent geological estimates. The velocity field shows several large undeforming areas, strain focused around some major faults, areas of diffuse strain, and dilation of the high plateau. We suggest that a new generation of dynamic models incorporating strength variations and strain-weakening mechanisms is required to explain the key observations. Seismic hazard in much of the region is elevated, not just near the major faults.

Buried shallow fault slip from the South Napa earthquake revealed by near-field geodesy

USGS Publications Warehouse

Brooks, Benjamin A.; Minson, Sarah E.; Glennie, Craig L.; Nevitt, Johanna; Dawson, Timothy E.; Rubin, Ron S.; Ericksen, Todd; Lockner, David A.; Hudnut, Kenneth W.; Langenheim, Victoria; Lutz, Andrew; Murray, Jessica R.; Schwartz, David P.; Zaccone, Dana

2017-01-01

Earthquake-related fault slip in the upper hundreds of meters of Earth’s surface has remained largely unstudied because of challenges measuring deformation in the near field of a fault rupture. We analyze centimeter-scale accuracy mobile laser scanning (MLS) data of deformed vine rows within ±300 m of the principal surface expression of the M (magnitude) 6.0 2014 South Napa earthquake. Rather than assuming surface displacement equivalence to fault slip, we invert the near-field data with a model that allows for, but does not require, the fault to be buried below the surface. The inversion maps the position on a preexisting fault plane of a slip front that terminates ~3 to 25 m below the surface coseismically and within a few hours postseismically. The lack of surface-breaching fault slip is verified by two trenches. We estimate near-surface slip ranging from ~0.5 to 1.25 m. Surface displacement can underestimate fault slip by as much as 30%. This implies that similar biases could be present in short-term geologic slip rates used in seismic hazard analyses. Along strike and downdip, we find deficits in slip: The along-strike deficit is erased after ~1 month by afterslip. We find no evidence of off-fault deformation and conclude that the downdip shallow slip deficit for this event is likely an artifact. As near-field geodetic data rapidly proliferate and will become commonplace, we suggest that analyses of near-surface fault rupture should also use more sophisticated mechanical models and subsurface geomechanical tests.

Metabarcoding avian diets at airports: implications for birdstrike hazard management planning

PubMed Central

2013-01-01

Background Wildlife collisions with aircraft cost the airline industry billions of dollars per annum and represent a public safety risk. Clearly, adapting aerodrome habitats to become less attractive to hazardous wildlife will reduce the incidence of collisions. Formulating effective habitat management strategies relies on accurate species identification of high-risk species. This can be successfully achieved for all strikes either through morphology and/or DNA-based identifications. Beyond species identification, dietary analysis of birdstrike gut contents can provide valuable intelligence for airport hazard management practices in regards to what food is attracting which species to aerodromes. Here, we present birdstrike identification and dietary data from Perth Airport, Western Australia, an aerodrome that saw approximately 140,000 aircraft movements in 2012. Next-generation high throughput DNA sequencing was employed to investigate 77 carcasses from 16 bird species collected over a 12-month period. Five DNA markers, which broadly characterize vertebrates, invertebrates and plants, were used to target three animal mitochondrial genes (12S rRNA, 16S rRNA, and COI) and a plastid gene (trnL) from DNA extracted from birdstrike carcass gastrointestinal tracts. Results Over 151,000 DNA sequences were generated, filtered and analyzed by a fusion-tag amplicon sequencing approach. Across the 77 carcasses, the most commonly identified vertebrate was Mus musculus (house mouse). Acrididae (grasshoppers) was the most common invertebrate family identified, and Poaceae (grasses) the most commonly identified plant family. The DNA-based dietary data has the potential to provide some key insights into feeding ecologies within and around the aerodrome. Conclusions The data generated here, together with the methodological approach, will greatly assist in the development of hazard management plans and, in combination with existing observational studies, provide an improved way to monitor the effectiveness of mitigation strategies (for example, netting of water, grass type, insecticides and so on) at aerodromes. It is hoped that with the insights provided by dietary data, airports will be able to allocate financial resources to the areas that will achieve the best outcomes for birdstrike reduction. PMID:24330620

DSOD Procedures for Seismic Hazard Analysis

NASA Astrophysics Data System (ADS)

Howard, J. K.; Fraser, W. A.

2005-12-01

DSOD, which has jurisdiction over more than 1200 dams in California, routinely evaluates their dynamic stability using seismic shaking input ranging from simple pseudostatic coefficients to spectrally matched earthquake time histories. Our seismic hazard assessments assume maximum earthquake scenarios of nearest active and conditionally active seismic sources. Multiple earthquake scenarios may be evaluated depending on sensitivity of the design analysis (e.g., to certain spectral amplitudes, duration of shaking). Active sources are defined as those with evidence of movement within the last 35,000 years. Conditionally active sources are those with reasonable expectation of activity, which are treated as active until demonstrated otherwise. The Division's Geology Branch develops seismic hazard estimates using spectral attenuation formulas applicable to California. The formulas were selected, in part, to achieve a site response model similar to the 2000 IBC's for rock, soft rock, and stiff soil sites. The level of dynamic loading used in the stability analysis (50th, 67th, or 84th percentile ground shaking estimates) is determined using a matrix that considers consequence of dam failure and fault slip rate. We account for near-source directivity amplification along such faults by adjusting target response spectra and developing appropriate design earthquakes for analysis of structures sensitive to long-period motion. Based on in-house studies, the orientation of the dam analysis section relative to the fault-normal direction is considered for strike-slip earthquakes, but directivity amplification is assumed in any orientation for dip-slip earthquakes. We do not have probabilistic standards, but we evaluate the probability of our ground shaking estimates using hazard curves constructed from the USGS Interactive De-Aggregation website. Typically, return periods for our design loads exceed 1000 years. Excessive return periods may warrant a lower design load. Minimum shaking levels are provided for sites far from active faulting. Our procedures and standards are presented at the DSOD website http://damsafety.water.ca.gov/. We review our methods and tools periodically under the guidance of our Consulting Board for Earthquake Analysis (and expect to make changes pending NGA completion), mindful that frequent procedural changes can interrupt design evaluations.

Kinematics, mechanics, and potential earthquake hazards for faults in Pottawatomie County, Kansas, USA

USGS Publications Warehouse

Ohlmacher, G.C.; Berendsen, P.

2005-01-01

Many stable continental regions have subregions with poorly defined earthquake hazards. Analysis of minor structures (folds and faults) in these subregions can improve our understanding of the tectonics and earthquake hazards. Detailed structural mapping in Pottawatomie County has revealed a suite consisting of two uplifted blocks aligned along a northeast trend and surrounded by faults. The first uplift is located southwest of the second. The northwest and southeast sides of these uplifts are bounded by northeast-trending right-lateral faults. To the east, both uplifts are bounded by north-trending reverse faults, and the first uplift is bounded by a north-trending high-angle fault to the west. The structural suite occurs above a basement fault that is part of a series of north-northeast-trending faults that delineate the Humboldt Fault Zone of eastern Kansas, an integral part of the Midcontinent Rift System. The favored kinematic model is a contractional stepover (push-up) between echelon strike-slip faults. Mechanical modeling using the boundary element method supports the interpretation of the uplifts as contractional stepovers and indicates that an approximately east-northeast maximum compressive stress trajectory is responsible for the formation of the structural suite. This stress trajectory suggests potential activity during the Laramide Orogeny, which agrees with the age of kimberlite emplacement in adjacent Riley County. The current stress field in Kansas has a N85??W maximum compressive stress trajectory that could potentially produce earthquakes along the basement faults. Several epicenters of seismic events (

What can we learn from the Wells, NV earthquake sequence about seismic hazard in the intermountain west?

USGS Publications Warehouse

Petersen, M.D.; Pankow, K.L.; Biasi, G.P.; Meremonte, M.

2008-01-01

The February 21, 2008 Wells, NV earthquake (M 6) was felt throughout eastern Nevada, southern Idaho, and western Utah. The town of Wells sustained significant damage to unreinforced masonry buildings. The earthquake occurred in a region of low seismic hazard with little seismicity, low geodetic strain rates, and few mapped faults. The peak horizontal ground acceleration predicted by the USGS National Seismic Hazard Maps is about 0.2 g at 2% probability of exceedance in 50 years, with the contributions coming mostly from the Ruby Mountain fault and background seismicity (M5-7.0). The hazard model predicts that the probability of occurrence of an M>6 event within 50 km of Wells is about 15% in 100 years. Although the earthquake was inside the USArray Transportable Array network, the nearest on-scale recordings of ground motions from the mainshock were too distant to estimate accelerations in town. The University of Nevada Reno, the University of Utah, and the U.S. Geological Survey deployed portable instruments to capture the ground motions from aftershocks of this rare normal-faulting event. Shaking from a M 4.7 aftershock recorded on portable instruments at distances less than 10 km exceeded 0.3 g, and sustained accelerations above 0.1 g lasted for about 5 seconds. For a magnitude 5 earthquake at 10 km distance the NGA equations predict median peak ground accelerations about 0.1 g. Ground motions from normal faulting earthquakes are poorly represented in the ground motion prediction equations. We compare portable and Transportable Array ground-motion recordings with prediction equations. Advanced National Seismic System stations in Utah recorded ground motions 250 km from the mainshock of about 2% g. The maximum ground motion recorded in Salt Lake City was in the center of the basin. We analyze the spatial variability of ground motions (rock vs. soil) and the influence of the Salt Lake Basin in modifying the ground motions. We then compare this data with the September 28, 2004 Parkfield aftershocks to contrast the differences between strike-slip and normal ground motions.

Metabarcoding avian diets at airports: implications for birdstrike hazard management planning.

PubMed

Coghlan, Megan L; White, Nicole E; Murray, Dáithí C; Houston, Jayne; Rutherford, William; Bellgard, Matthew I; Haile, James; Bunce, Michael

2013-12-11

Wildlife collisions with aircraft cost the airline industry billions of dollars per annum and represent a public safety risk. Clearly, adapting aerodrome habitats to become less attractive to hazardous wildlife will reduce the incidence of collisions. Formulating effective habitat management strategies relies on accurate species identification of high-risk species. This can be successfully achieved for all strikes either through morphology and/or DNA-based identifications. Beyond species identification, dietary analysis of birdstrike gut contents can provide valuable intelligence for airport hazard management practices in regards to what food is attracting which species to aerodromes. Here, we present birdstrike identification and dietary data from Perth Airport, Western Australia, an aerodrome that saw approximately 140,000 aircraft movements in 2012. Next-generation high throughput DNA sequencing was employed to investigate 77 carcasses from 16 bird species collected over a 12-month period. Five DNA markers, which broadly characterize vertebrates, invertebrates and plants, were used to target three animal mitochondrial genes (12S rRNA, 16S rRNA, and COI) and a plastid gene (trnL) from DNA extracted from birdstrike carcass gastrointestinal tracts. Over 151,000 DNA sequences were generated, filtered and analyzed by a fusion-tag amplicon sequencing approach. Across the 77 carcasses, the most commonly identified vertebrate was Mus musculus (house mouse). Acrididae (grasshoppers) was the most common invertebrate family identified, and Poaceae (grasses) the most commonly identified plant family. The DNA-based dietary data has the potential to provide some key insights into feeding ecologies within and around the aerodrome. The data generated here, together with the methodological approach, will greatly assist in the development of hazard management plans and, in combination with existing observational studies, provide an improved way to monitor the effectiveness of mitigation strategies (for example, netting of water, grass type, insecticides and so on) at aerodromes. It is hoped that with the insights provided by dietary data, airports will be able to allocate financial resources to the areas that will achieve the best outcomes for birdstrike reduction.

76 FR 2730 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-14

... exchanges that employ a similar $5 Strike Price Program under their respective rules. Similar reciprocity... securities exchanges. Similar reciprocity currently is permitted with BOX's $1 Strike Program, $.50 Strike... effectiveness of reciprocity provision related to the $5 Strike Price Program). \\15\\ For purposes only of...

Strike-parallel and strike-normal coordinate system around geometrically complicated rupture traces: use by NGA-West2 and further improvements

USGS Publications Warehouse

Spudich, Paul A.; Chiou, Brian

2015-01-01

We present a two-dimensional system of generalized coordinates for use with geometrically complex fault ruptures that are neither straight nor continuous. The coordinates are a generalization of the conventional strike-normal and strike-parallel coordinates of a single straight fault. The presented conventions and formulations are applicable to a single curved trace, as well as multiple traces representing the rupture of branching faults or noncontiguous faults. An early application of our generalized system is in the second round of the Next Generation of Ground-Motion Attenuation Model project for the Western United States (NGA-West2), where they were used in the characterization of the hanging-wall effects. We further improve the NGA-West2 strike-parallel formulation for multiple rupture traces with a more intuitive definition of the nominal strike direction. We also derive an analytical expression for the gradient of the generalized strike-normal coordinate. The direction of this gradient may be used as the strike-normal direction in the study of polarization effects on ground motions.

Lower limb joint angles and ground reaction forces in forefoot strike and rearfoot strike runners during overground downhill and uphill running.

PubMed

Kowalski, Erik; Li, Jing Xian

2016-11-01

This study investigated the normal and parallel ground reaction forces during downhill and uphill running in habitual forefoot strike and habitual rearfoot strike (RFS) runners. Fifteen habitual forefoot strike and 15 habitual RFS recreational male runners ran at 3 m/s ± 5% during level, uphill and downhill overground running on a ramp mounted at 6° and 9°. Results showed that forefoot strike runners had no visible impact peak in all running conditions, while the impact peaks only decreased during the uphill conditions in RFS runners. Active peaks decreased during the downhill conditions in forefoot strike runners while active loading rates increased during downhill conditions in RFS runners. Compared to the level condition, parallel braking peaks were larger during downhill conditions and parallel propulsive peaks were larger during uphill conditions. Combined with previous biomechanics studies, our findings suggest that forefoot strike running may be an effective strategy to reduce impacts, especially during downhill running. These findings may have further implications towards injury management and prevention.

Orthotic intervention in forefoot and rearfoot strike running patterns.

PubMed

Stackhouse, Carrie Laughton; Davis, Irene McClay; Hamill, Joseph

2004-01-01

To compare the differential effect of custom orthoses on the lower extremity mechanics of a forefoot and rearfoot strike pattern. Fifteen subjects ran with both a forefoot and a rearfoot strike pattern with and without orthoses. Lower extremity kinematic and kinetic variables were compared between strike pattern and orthotic conditions. Foot orthoses have been shown to be effective in controlling excessive rearfoot motion in rearfoot strikers. The effect of orthotic intervention on rearfoot motion in forefoot strikers has not been previously reported. Five trials were collected for each condition. Peak rearfoot eversion, eversion excursion, eversion velocity, peak inversion moment, and inversion work were compared between conditions. Kinematic variables in the sagittal plane of the rearfoot and in the frontal and sagittal plane of the knee were also determined. Increased rearfoot excursions and velocities and decreased peak eversion were noted in the forefoot strike pattern compared to the rearfoot strike pattern. Orthotic intervention, however,did not significantly change rearfoot motion in either strike pattern. Reductions in internal rotation and abduction of the knee were noted with orthotic intervention. Foot orthoses do not differentially effect rearfoot motion of a rearfoot strike and a forefoot strike running pattern. Orthotic intervention has a larger and more systematic effect on rearfoot kinetics compared to rearfoot kinematics.

Variation in Foot Strike Patterns among Habitually Barefoot and Shod Runners in Kenya.

PubMed

Lieberman, Daniel E; Castillo, Eric R; Otarola-Castillo, Erik; Sang, Meshack K; Sigei, Timothy K; Ojiambo, Robert; Okutoyi, Paul; Pitsiladis, Yannis

2015-01-01

Runners are often categorized as forefoot, midfoot or rearfoot strikers, but how much and why do individuals vary in foot strike patterns when running on level terrain? This study used general linear mixed-effects models to explore both intra- and inter-individual variations in foot strike pattern among 48 Kalenjin-speaking participants from Kenya who varied in age, sex, body mass, height, running history, and habitual use of footwear. High speed video was used to measure lower extremity kinematics at ground contact in the sagittal plane while participants ran down 13 meter-long tracks with three variables independently controlled: speed, track stiffness, and step frequency. 72% of the habitually barefoot and 32% of the habitually shod participants used multiple strike types, with significantly higher levels of foot strike variation among individuals who ran less frequently and who used lower step frequencies. There was no effect of sex, age, height or weight on foot strike angle, but individuals were more likely to midfoot or forefoot strike when they ran on a stiff surface, had a high preferred stride frequency, were habitually barefoot, and had more experience running. It is hypothesized that strike type variation during running, including a more frequent use of forefoot and midfoot strikes, used to be greater before the introduction of cushioned shoes and paved surfaces.

Factors affecting defensive strike behavior in Brown Treesnakes (Boiga irregularis) provoked by humans

USGS Publications Warehouse

Spencer, McKayka M.; Lardner, Bjorn; Mazurek, M.J.; Reed, Robert N.

2015-01-01

Striking is a typical antipredator defense exhibited by many species of snakes. While trapping Brown Treesnakes (Boiga irregularis) on Guam, we observed that snakes most frequently struck at an approaching person at a site where snakes had been trapped, marked, and handled in the past. Using a combination of between-sites and within-site comparisons, we assessed if the propensity to strike was correlated with capture histories (both recent and long-term), snake size, body condition (a proxy to nutritional stress), sex, or tail condition (broken or intact), while controlling for confounding variables. We confirmed that propensity to strike was higher at the site where we had been conducting capture-mark-recapture for several years. However, we were unable to demonstrate a correlation between striking tendencies and individual recent or long-term capture histories. The only morphological covariate that had an effect on strike propensity was sex, with females striking more often than males. After removing the site effect from our model, we found that snakes missing parts of their tails were more likely to strike than snakes with intact tails. We have yet to identify the factor(s) that cause the pronounced difference across sites in snake propensity to strike, and data from additional sites might help elucidate any geographical patterns.

Martial arts striking hand peak acceleration, accuracy and consistency.

PubMed

Neto, Osmar Pinto; Marzullo, Ana Carolina De Miranda; Bolander, Richard P; Bir, Cynthia A

2013-01-01

The goal of this paper was to investigate the possible trade-off between peak hand acceleration and accuracy and consistency of hand strikes performed by martial artists of different training experiences. Ten male martial artists with training experience ranging from one to nine years volunteered to participate in the experiment. Each participant performed 12 maximum effort goal-directed strikes. Hand acceleration during the strikes was obtained using a tri-axial accelerometer block. A pressure sensor matrix was used to determine the accuracy and consistency of the strikes. Accuracy was estimated by the radial distance between the centroid of each subject's 12 strikes and the target, whereas consistency was estimated by the square root of the 12 strikes mean squared distance from their centroid. We found that training experience was significantly correlated to hand peak acceleration prior to impact (r(2)=0.456, p =0.032) and accuracy (r(2)=0. 621, p=0.012). These correlations suggest that more experienced participants exhibited higher hand peak accelerations and at the same time were more accurate. Training experience, however, was not correlated to consistency (r(2)=0.085, p=0.413). Overall, our results suggest that martial arts training may lead practitioners to achieve higher striking hand accelerations with better accuracy and no change in striking consistency.

Early care of acute hyperglycemia benefits the outcome of traumatic brain injury in rats.

PubMed

Kang, Xin; Liu, Yuepeng; Yuan, Tao; Jiang, Na-Na; Dong, Yan-Bin; Wang, Jian-Wei; Fu, Guang-Hui; Liu, Yu-Liang; Wang, Wen-Xue

2016-11-01

Previous animal studies showed contradictory clinical observations on whether acute hyperglycemia contributes to poor outcome in traumatic brain injury (TBI). Herein, we tried to clarify this issue. Striking with depths of 3.0-4.25mm at right occipitoparietal brain region and with depth of 3.75mm at right/left occipitoparietal or right/left frontoparietal brain region were performed, respectively. Blood glucose and insulin levels were traced every four hours from 1 to 72h after striking. HOMA2-%S and HOMA2-%β were calculated. Modified neurological severity scores (mNSS) were used to evaluate neurological deficit within 72h. Striking with depths of 3.5-4.25mm induced increase in blood glucose lasting up to 24h after striking. The levels of blood glucose after striking with depths of 3.75-4.25mm were significantly different from that of striking with the depth of 3.0mm. Striking with depth of 3.75mm at right/left occipitoparietal region induced higher blood glucose in 24h than that at right/left frontoparietal region. Insulin concentration increased slowly during 72h after striking. Striking also induced decrease in insulin sensitivity and secretion lasting 72h. Evaluation of mNSS revealed that severe striking (beyond 3.75mm) worsened nerve function than slight striking (<3.0mm). Intervention of acute hyperglycemia could decrease the mNSS from 2 to 7 days after TBI. Our results suggested that only severe TBI could induce acute hyperglycemia by itself, and early care of acute hyperglycemia could benefit the outcome of TBI patients. Copyright © 2016 Elsevier B.V. All rights reserved.

Absolute probability estimates of lethal vessel strikes to North Atlantic right whales in Roseway Basin, Scotian Shelf.

PubMed

van der Hoop, Julie M; Vanderlaan, Angelia S M; Taggart, Christopher T

2012-10-01

Vessel strikes are the primary source of known mortality for the endangered North Atlantic right whale (Eubalaena glacialis). Multi-institutional efforts to reduce mortality associated with vessel strikes include vessel-routing amendments such as the International Maritime Organization voluntary "area to be avoided" (ATBA) in the Roseway Basin right whale feeding habitat on the southwestern Scotian Shelf. Though relative probabilities of lethal vessel strikes have been estimated and published, absolute probabilities remain unknown. We used a modeling approach to determine the regional effect of the ATBA, by estimating reductions in the expected number of lethal vessel strikes. This analysis differs from others in that it explicitly includes a spatiotemporal analysis of real-time transits of vessels through a population of simulated, swimming right whales. Combining automatic identification system (AIS) vessel navigation data and an observationally based whale movement model allowed us to determine the spatial and temporal intersection of vessels and whales, from which various probability estimates of lethal vessel strikes are derived. We estimate one lethal vessel strike every 0.775-2.07 years prior to ATBA implementation, consistent with and more constrained than previous estimates of every 2-16 years. Following implementation, a lethal vessel strike is expected every 41 years. When whale abundance is held constant across years, we estimate that voluntary vessel compliance with the ATBA results in an 82% reduction in the per capita rate of lethal strikes; very similar to a previously published estimate of 82% reduction in the relative risk of a lethal vessel strike. The models we developed can inform decision-making and policy design, based on their ability to provide absolute, population-corrected, time-varying estimates of lethal vessel strikes, and they are easily transported to other regions and situations.

Active Structures in the Georgia Basin, NW Washington State, USA, and SW British Columbia, Canada

NASA Astrophysics Data System (ADS)

Polivka, P.; Riedel, M.; Pratt, T. L.

2013-12-01

The Georgia basin is a local depression in the Cascadia forearc straddling the USA-Canadian border that hosts Canada's largest west coast population. The basin contains late Pleistocene and Holocene sediments overlying a thick sequence of Eocene and Cretaceous sedimentary rocks and is currently experiencing N-S shortening. Tectonic structures capable of accommodating this N-S shortening are recognized in Oregon and Washington; however, none have been identified in southwest Canada despite multiple independent geodetic studies indicating that shortening continues further north. This conflict of observed shortening over a region without recognized active structures suggests that seismic hazard may be underestimated in Canada. We combine multiple seismic reflection surveys and multibeam bathymetry with published geophysical data and on-shore mapping to identify active structures and assess seismic hazard. Reflection datasets span the USA-CA border and include those from the deep 1998 Seismic Hazards Investigations of Puget Sound (SHIPS), high resolution 2002 SHIPS, localized sparker, and deep industry lines. These data are augmented by digitized paper records of past reflection surveys. The 1998 SHIPS and industry lines show strong reflections of folded and faulted Cretaceous and Eocene sedimentary bedrock to 5 km depth. Shallow sediment deformation is imaged on the 2002 SHIPS and sparker lines. Combining these profiles, bathymetry, and surficial bedrock mapping in a 3-D interpretation program facilitated the correlation of features across multiple 2-D seismic lines, allowing us to interpret four new regional stratigraphic and tectonic characteristics. (1) The 1997 ML4.6 Gabriola Island earthquake was a north-side up thrust event occurring 30 km west of Vancouver at ~3.5 km depth. The event was previously correlated with a zone of low coherence on the SHIPS 1998 line. We reprocessed the line and imaged distinct reflector terminations. A generally E-W strike is interpreted from regional bedrock fault trends and shallow sediment deformation imaged on the 2002 SHIPS lines. (2) Kelsey et al. (2012, JGR) identified three subparallel NW-striking faults in NW Washington. We use the industry lines to constrain the subsurface geometries of these faults to >4 km depth. (3) Interpreting on-shore mapping, bathymetric bedrock ridges, and intersecting deep seismic profiles, we conclude that the E-K boundary is an angular unconformity across and along the length of the basin. (4) We correlate kinks in bathymetric bedrock ridges with bedrock folds on the intersecting SHIPS 1998 profile to re-interpret previously identified NE-trending 'secondary faults' as blind and broken-through fault-propagation folds. These faults are orthogonal to the subduction margin and collectively deemed the Vancouver Fold and Thrust Belt. The Gabriola Island earthquake indicates that the fault system is active, and likely accommodates at least part of the strain measured on GPS networks but not accounted for in previous tectonic models.

GPS and InSAR Monitoring of the Mogul Swarm: Evidence for Mainly Aseismic Fault Creep, with Implications for Seismic Hazard

NASA Astrophysics Data System (ADS)

Blewitt, G.; Bell, J.; Hammond, W. C.; Kreemer, C.; Plag, H.; Depolo, C.

2008-12-01

The relative fraction of aseismic slip that occurs in the seismogenic zone has implications for earthquake hazard, because aseismic creep tends to release stresses that have accumulated by relative plate motion. The phenomenon of aseismic fault creep is well documented in segments of the San Andreas Fault, in Japan, and more recently, in the Cascadia subduction zone where creep occurs episodically in "slow earthquakes", as detected by continuous GPS (CGPS). Another mechanism for fault creep is afterslip following large or great earthquakes, which can rival the magnitude of the displacement associated with the main shock, as was the case for the 2005 Mw 8.7 Nias Earthquake, again detected by CGPS. Here we report on the CGPS detection of aseismic fault creep that significantly exceeds the co-seismic displacement of the moderate Mw 5.0 Mogul earthquake of 26 April 2008. This was the largest event of the Mogul-Somersett earthquake swarm that lasted from approximately March-July, 2008, a few km west of Reno, Nevada, USA. We installed the GPS network in March 2008, in rapid response to the onset of the swarm. The network has an inter-station spacing of ~2 km in the near field. The GPS data indicate that aseismic afterslip occurred for several weeks after the main event, with a decaying signature. Two stations apparently straddled the previously unrecognized NNW-SSE striking fault, and detected a total displacement of ~40 mm toward each other, yet only ~15 mm occurred on 26 April. As such, the Mw 5.0 event and the subsequent afterslip is perhaps the smallest event to have ever been observed directly by several GPS stations. Our modeling of the event is also constrained by InSAR, which helps constrain spatial details of the slip distribution. Results to date already indicate that the GPS and InSAR constraints appear to be compatible. The post-seismic surface displacement field has the same general pattern of the co-seismic displacement field, consistent with models of shallow slip (a few km) on a NNW-trending right-lateral strike-slip fault. Despite an extensive search on the ground, no surface rupture was found in the area of this modeled fault. Two potentially important questions arise from these observations: (1) Is mainly aseismic slip the rule or the exception for all moderate magnitude earthquakes, or is this only typically associated with shallow earthquake swarms like the 2008 Mogul-Somersett sequence? (2) What is the implication of the answer to the first question for monitoring earthquakes using InSAR, which is limited by the time interval between repeat passes? One thing that is clear, is that rapid-response GPS will be required to address these questions, which are important for the assessment of seismic hazards.

Striking Out on Their Own: Lessons Learned from Student Teaching during and after the Chicago Teachers Union Strike

ERIC Educational Resources Information Center

Horn, Brian

2017-01-01

This study looks at the experiences of pre-service teachers who began their student teaching assignments amidst the 2012 Chicago Teachers Union strike. Four yearlong student teachers reflected on their understandings of teaching, unionism, and activism before, during, and after the strike. Findings suggest pre-service teachers need greater…

76 FR 5646 - Self-Regulatory Organizations; NYSE Amex LLC; Order Granting Approval of Proposed Rule Change...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-01

... strike prices and non-parallel strikes in different expiration months of the same issue. The Commission... Listing of Options Series With $1 Strike Prices January 25, 2011. I. Introduction On November 24, 2010... Strike Price Program. The proposed rule change was published for comment in the Federal Register on...

A model of high-rate indentation of a cylindrical striking pin into a deformable body

NASA Astrophysics Data System (ADS)

Zalazinskaya, E. A.; Zalazinsky, A. G.

2017-12-01

Mathematical modeling of an impact and high-rate indentation to a significant depth of a flat-faced hard cylindrical striking pin into a massive deformable target body is carried out. With the application of the kinematic extreme theorem of the plasticity theory and the kinetic energy variation theorem, the phase trajectories of the striking pin are calculated, the initial velocity of the striking pin in the body, the limit values of the inlet duct length, and the depth of striking pin penetration into the target are determined.

Manipulation of Foot Strike and Footwear Increases Achilles Tendon Loading During Running.

PubMed

Rice, Hannah; Patel, Mubarak

2017-08-01

The Achilles tendon is the most common site of tendon overuse injury in humans. Running with a forefoot strike pattern and in minimal shoes is a topic of recent interest, yet evidence is currently limited regarding the combined influence of foot strike and footwear on Achilles tendon loading. To investigate the influence of both foot strike and footwear on Achilles tendon loading in habitual rearfoot strike runners. Controlled laboratory study. Synchronized kinematic and force data were collected from 22 habitual rearfoot strikers (11 male), who habitually ran in nonminimal running shoes, during overground running at 3.6 m·s -1 . Participants ran in 3 different footwear conditions (standard running shoe, minimal running shoe, and barefoot) with both a rearfoot strike (RFS) and an imposed forefoot strike (FFS) in each footwear condition. Achilles tendon loading was estimated by use of inverse dynamics, where the Achilles tendon moment arm was determined with a regression equation. A 2-way, repeated-measures analysis of variance was used to compare conditions. Achilles tendon impulse was greater when subjects ran with an FFS rather than an RFS in minimal shoes. Achilles tendon loading rates were higher when subjects ran either in minimal shoes or barefoot than in standard shoes, regardless of foot strike. In runners who habitually rearfoot strike in standard running shoes, running in minimal shoes or barefoot increased the rate of tendon loading, and running with a forefoot strike in minimal shoes increased the magnitude of tendon loading. Transitioning to these running conditions may increase the risk of tendinopathy.

Assessing movement quality in persons with severe mental illness - Reliability and validity of the Body Awareness Scale Movement Quality and Experience.

PubMed

Hedlund, Lena; Gyllensten, Amanda Lundvik; Waldegren, Tomas; Hansson, Lars

2016-05-01

Motor disturbances and disturbed self-recognition are common features that affect mobility in persons with schizophrenia spectrum disorder and bipolar disorder. Physiotherapists in Scandinavia assess and treat movement difficulties in persons with severe mental illness. The Body Awareness Scale Movement Quality and Experience (BAS MQ-E) is a new and shortened version of the commonly used Body Awareness Scale-Health (BAS-H). The purpose of this study was to investigate the inter-rater reliability and the concurrent validity of BAS MQ-E in persons with severe mental illness. The concurrent validity was examined by investigating the relationships between neurological soft signs, alexithymia, fatigue, anxiety, and mastery. Sixty-two persons with severe mental illness participated in the study. The results showed a satisfactory inter-rater reliability (n = 53) and a concurrent validity (n = 62) with neurological soft signs, especially cognitive and perceptual based signs. There was also a concurrent validity linked to physical fatigue and aspects of alexithymia. The scores of BAS MQ-E were in general higher for persons with schizophrenia compared to persons with other diagnoses within the schizophrenia spectrum disorders and bipolar disorder. The clinical implications are presented in the discussion.

Conventions and workflows for using Situs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wriggers, Willy, E-mail: wriggers@biomachina.org

2012-04-01

Recent developments of the Situs software suite for multi-scale modeling are reviewed. Typical workflows and conventions encountered during processing of biophysical data from electron microscopy, tomography or small-angle X-ray scattering are described. Situs is a modular program package for the multi-scale modeling of atomic resolution structures and low-resolution biophysical data from electron microscopy, tomography or small-angle X-ray scattering. This article provides an overview of recent developments in the Situs package, with an emphasis on workflows and conventions that are important for practical applications. The modular design of the programs facilitates scripting in the bash shell that allows specific programs tomore » be combined in creative ways that go beyond the original intent of the developers. Several scripting-enabled functionalities, such as flexible transformations of data type, the use of symmetry constraints or the creation of two-dimensional projection images, are described. The processing of low-resolution biophysical maps in such workflows follows not only first principles but often relies on implicit conventions. Situs conventions related to map formats, resolution, correlation functions and feature detection are reviewed and summarized. The compatibility of the Situs workflow with CCP4 conventions and programs is discussed.« less

Variation in Foot Strike Patterns among Habitually Barefoot and Shod Runners in Kenya

PubMed Central

Lieberman, Daniel E.; Castillo, Eric R.; Otarola-Castillo, Erik; Sang, Meshack K.; Sigei, Timothy K.; Ojiambo, Robert; Okutoyi, Paul; Pitsiladis, Yannis

2015-01-01

Runners are often categorized as forefoot, midfoot or rearfoot strikers, but how much and why do individuals vary in foot strike patterns when running on level terrain? This study used general linear mixed-effects models to explore both intra- and inter-individual variations in foot strike pattern among 48 Kalenjin-speaking participants from Kenya who varied in age, sex, body mass, height, running history, and habitual use of footwear. High speed video was used to measure lower extremity kinematics at ground contact in the sagittal plane while participants ran down 13 meter-long tracks with three variables independently controlled: speed, track stiffness, and step frequency. 72% of the habitually barefoot and 32% of the habitually shod participants used multiple strike types, with significantly higher levels of foot strike variation among individuals who ran less frequently and who used lower step frequencies. There was no effect of sex, age, height or weight on foot strike angle, but individuals were more likely to midfoot or forefoot strike when they ran on a stiff surface, had a high preferred stride frequency, were habitually barefoot, and had more experience running. It is hypothesized that strike type variation during running, including a more frequent use of forefoot and midfoot strikes, used to be greater before the introduction of cushioned shoes and paved surfaces. PMID:26154285

75 FR 35871 - Self-Regulatory Organizations; Notice of Filing and Immediate Effectiveness of Proposed Rule...

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2010-06-23

... PHLX, Inc. To List Options on Trust Issued Receipts in $1 Strike Intervals June 15, 2010. Pursuant to... to list options on Trust Issued Receipts in $1 strike price intervals. The text of the proposed rule...)(iv) to Rule 1012, in $1 or greater strike price intervals, where the strike price is $200 or less and...

78 FR 69465 - Self-Regulatory Organizations; NYSE MKT LLC; Notice of Filing and Immediate Effectiveness of...

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2013-11-19

...-money strikes. Elimination of the cap would remedy this issue. Currently, the Exchange lists quarterly... additional strikes. Consequently, the Exchange is not able to list important at-the-money strikes due to the... so that it may list strikes that are closer to the money, delisting is not always possible. If all of...

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Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-15

... Commission has recently approved certain products to trade at $0.50 and $1 strike price intervals on CBOE... Series (``STOS'') Program that normally trade in $1 Strike Price Intervals shall be $0.50 or greater; and for classes in the STOS Program that do not normally trade in $1 Strike Price Intervals, the strike...

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2012-02-13

... Trust 1 and United States Oil Fund at $0.50 Strike Price Intervals Where the Strike Price Is Less Than... interested persons. \\1\\ ``iShares[supreg]'' is a registered trademark of BlackRock Institutional Trust...[supreg] Silver Trust \\5\\ and United States Oil Fund at $0.50 strike price intervals where the strike...

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2012-02-13

...] Silver Trust \\1\\ and United States Oil Fund at $0.50 Strike Price Intervals Where the Strike Price Is Less Than $75 \\1\\ ``iShares[supreg]'' is a registered trademark BlackRock Institutional Trust Company...] Silver Trust \\5\\ and United States Oil Fund at $0.50 strike price intervals where the strike price is...

Acute changes in foot strike pattern and cadence affect running parameters associated with tibial stress fractures.

PubMed

Yong, Jennifer R; Silder, Amy; Montgomery, Kate L; Fredericson, Michael; Delp, Scott L

2018-05-18

Tibial stress fractures are a common and debilitating injury that occur in distance runners. Runners may be able to decrease tibial stress fracture risk by adopting a running pattern that reduces biomechanical parameters associated with a history of tibial stress fracture. The purpose of this study was to test the hypothesis that converting to a forefoot striking pattern or increasing cadence without focusing on changing foot strike type would reduce injury risk parameters in recreational runners. Running kinematics, ground reaction forces and tibial accelerations were recorded from seventeen healthy, habitual rearfoot striking runners while running in their natural running pattern and after two acute retraining conditions: (1) converting to forefoot striking without focusing on cadence and (2) increasing cadence without focusing on foot strike. We found that converting to forefoot striking decreased two risk factors for tibial stress fracture: average and peak loading rates. Increasing cadence decreased one risk factor: peak hip adduction angle. Our results demonstrate that acute adaptation to forefoot striking reduces different injury risk parameters than acute adaptation to increased cadence and suggest that both modifications may reduce the risk of tibial stress fractures. Copyright © 2018 Elsevier Ltd. All rights reserved.

Influence of fault trend, fault bends, and fault convergence on shallow structure, geomorphology, and hazards, Hosgri strike-slip fault, offshore central California

NASA Astrophysics Data System (ADS)

Johnson, S. Y.; Watt, J. T.; Hartwell, S. R.

2012-12-01

We mapped a ~94-km-long portion of the right-lateral Hosgri Fault Zone from Point Sal to Piedras Blancas in offshore central California using high-resolution seismic reflection profiles, marine magnetic data, and multibeam bathymetry. The database includes 121 seismic profiles across the fault zone and is perhaps the most comprehensive reported survey of the shallow structure of an active strike-slip fault. These data document the location, length, and near-surface continuity of multiple fault strands, highlight fault-zone heterogeneity, and demonstrate the importance of fault trend, fault bends, and fault convergences in the development of shallow structure and tectonic geomorphology. The Hosgri Fault Zone is continuous through the study area passing through a broad arc in which fault trend changes from about 338° to 328° from south to north. The southern ~40 km of the fault zone in this area is more extensional, resulting in accommodation space that is filled by deltaic sediments of the Santa Maria River. The central ~24 km of the fault zone is characterized by oblique convergence of the Hosgri Fault Zone with the more northwest-trending Los Osos and Shoreline Faults. Convergence between these faults has resulted in the formation of local restraining and releasing fault bends, transpressive uplifts, and transtensional basins of varying size and morphology. We present a hypothesis that links development of a paired fault bend to indenting and bulging of the Hosgri Fault by a strong crustal block translated to the northwest along the Shoreline Fault. Two diverging Hosgri Fault strands bounding a central uplifted block characterize the northern ~30 km of the Hosgri Fault in this area. The eastern Hosgri strand passes through releasing and restraining bends; the releasing bend is the primary control on development of an elongate, asymmetric, "Lazy Z" sedimentary basin. The western strand of the Hosgri Fault Zone passes through a significant restraining bend and dies out northward where we propose that its slip transfers to active structures in the Piedras Blancas fold belt. Given the continuity of the Hosgri Fault Zone through our study area, earthquake hazard assessments should incorporate a minimum rupture length of 110 km. Our data do not constrain lateral slip rates on the Hosgri, which probably vary along the fault (both to the north and south) as different structures converge and diverge but are likely in the geodetically estimated range of 2 to 4 mm/yr. More focused mapping of lowstand geomorphic features (e.g., channels, paleoshorelines) has the potential to provide better constraints. The post-Last-Glacial Maximum unconformity is an important surface for constraining vertical deformation, yielding local fault offset rates that may be as high as 1.4 mm/yr and off-fault deformation rates as high as 0.5 mm/yr. These vertical rates are short-term and not sustainable over longer geologic time, emphasizing the complex evolution and dynamics of strike-slip zones.

Persistency of rupture directivity in moderate-magnitude earthquakes in Italy: Implications for seismic hazard

NASA Astrophysics Data System (ADS)

Rovelli, A.; Calderoni, G.

2012-12-01

A simple method based on the EGF deconvolution in the frequency domain is applied to detect the occurrence of unilateral ruptures in recent damaging earthquakes in Italy. The spectral ratio between event pairs with different magnitudes at individual stations shows large azimuthal variations above corner frequency when the target event is affected by source directivity and the EGF is not or vice versa. The analysis is applied to seismograms and accelerograms recorded during the seismic sequence following the 20 May 2012, Mw 5.6 main shock in Emilia, northern Italy, the 6 April 2009, Mw 6.1 earthquake of L'Aquila, central Italy, and the 26 September 1997, Mw 5.7 and 6.0 shocks in Umbria-Marche, central Italy. Events of each seismic sequence are selected as having consistent focal mechanisms, and the station selection obeys to the constraint of a similar source-to-receiver path for the event pairs. The analyzed data set of L'Aquila consists of 962 broad-band seismograms relative to 69 normal-faulting earthquakes (3.3 ≤ MW ≤ 6.1, according to Herrmann et al., 2011), stations are selected in the distance range 100 to 250 km to minimize differences in propagation paths. The seismogram analysis reveals that a strong along-strike (toward SE) source directivity characterized all of the three Mw > 5.0 shocks. Source directivity was also persistent up to the smallest magnitudes: 65% of earthquakes under study showed evidence of directivity toward SE whereas only one (Mw 3.7) event showed directivity in the opposite direction. Also the Mw 5.6 main shock of the 20 May 2012 in Emilia result in large azimuthal spectral variations indicating unilateral rupture propagation toward SE. According to the reconstructed geometry of the trust-fault plane, the inferred directivity direction suggests top-down rupture propagation. The analysis over the Emilia aftershock sequence is in progress. The third seismic sequence, dated 1997-1998, occurred in the northern Apennines and, similarly to L'Aquila faults, was characterized by normal-faulting earthquakes with strike substantially parallel to the Apennine trend. Although the amount of data is not as abundant as for the most recent earthquakes, the available data were already object of previous studies indicating unilateral rupture propagation in several of the strongest (5.5 < Mw < 6.0) shocks. We show that the effect of directivity is particularly significant in intermontane basins where long-period (T > 1 sec) ground motions are amplified by soft sediments and the combination of local amplification with source directivity causes exceedance of spectral ordinates at those periods up to more than 2 standard deviations from the expected values of commonly used GMPEs for soft sites. These results arise a concern in terms of seismic hazard because source directivity is found to be recurrent feature in the Apennines. Moreover, the predominant fault strike and intermontane basins are both aligned along the Apennine chain offering a condition potentially favorable to extra-amplifications at periods relevant to seismic risk.

Modern Protection Against Lightning Strikes

NASA Astrophysics Data System (ADS)

Moore, C.

2005-05-01

The application of science to provide protection against lightning strikes began around 1750 when Benjamin Franklin who invented the lightning rod in an effort to discharge thunderclouds. Instead of preventing lightning as he expected, his rods have been quite successful as strike receptors, intercepting cloud-to ground discharges and conducting them to Earth without damage to the structures on which they are mounted. In the years since Franklin's invention there has been little attention paid to the rod configuration that best serves as a strike receptor but Franklin's original ideas continue to be rediscovered and promoted. Recent measurements of the responses of variously configured rods to nearby strikes indicate that sharp-tipped rods are not the optimum configuration to serve as strike receptors since the ionization of the air around their tips limits the strength of the local electric fields created by an approaching lightning leader. In these experiments, fourteen blunt-tipped rods exposed in strike-reception competitions with nearby sharp-tipped rods were struck by lightning but none of the sharp-tipped rods were struck.

Expertise of using striking techniques for power stroke in badminton.

PubMed

Zhu, Qin

2013-10-01

Two striking techniques (fast swing and angled striking) were examined to see if they allowed effective use of string tension for the power stroke in badminton. 12 participants (4 novices, 4 recreational, and 4 expert badminton players) were recorded by a fast-speed camera while striking a shuttlecock with racquets of 8 different string tensions. The peak speed of the shuttlecock, the racquet angle and the shuttlecock angle were analyzed. The results showed that expert players succeeded in using both striking techniques to overcome the constraint of string tension and produce a consistently superior stroke. Failure to use either striking technique resulted in inferior performance that was constrained by string tension. Expertise in badminton allows the necessary motor adjustments based on the affordance perception of the string tension.

Head Trauma in Mixed Martial Arts.

PubMed

Hutchison, Michael G; Lawrence, David W; Cusimano, Michael D; Schweizer, Tom A

2014-06-01

Mixed martial arts (MMA) is a full combative sport with a recent global increase in popularity despite significant scrutiny from medical associations. To date, the empirical research of the risk of head injuries associated with this sport is limited. Youth and amateur participation is growing, warranting investigation into the burden and mechanism of injuries associated with this sport. (1) To determine the incidence, risk factors, and characteristics of knockouts (KOs) and technical knockouts (TKOs) from repetitive strikes in professional MMA; and (2) to identify the mechanisms of head trauma and the situational factors that lead to KOs and TKOs secondary to repetitive strikes through video analysis. Descriptive epidemiology study. Competition data and video records for all KOs and TKOs from numbered Ultimate Fighting Championship MMA events (n = 844) between 2006 to 2012. Analyses included (1) multivariate logistic regression to investigate factors associated with an increased risk of sustaining a KO or TKO secondary to repetitive strikes and (2) video analysis of all KOs and TKOs secondary to repetitive strikes with descriptive statistics. During the study period, the KO rate was 6.4 per 100 athlete-exposures (AEs) (12.7% of matches), and the rate of TKOs secondary to repetitive strikes was 9.5 per 100 AEs (19.1% of matches), for a combined incidence of match-ending head trauma of 15.9 per 100 AEs (31.9% of matches). Logistic regression identified that weight class, earlier time in a round, earlier round in a match, and older age were risk factors for both KOs and TKOs secondary to repetitive strikes. Match significance and previously sustained KOs or TKOs were also risk factors for KOs. Video analysis identified that all KOs were the result of direct impact to the head, most frequently a strike to the mandibular region (53.9%). The average time between the KO-strike and match stoppage was 3.5 seconds (range, 0-20 seconds), with losers sustaining an average of 2.6 additional strikes (range, 0-20 strikes) to the head. For TKOs secondary to strikes, in the 30-second interval immediately preceding match stoppage, losers sustained, on average, 18.5 strikes (range, 5-46 strikes), with 92.3% of these being strikes to the head. Rates of KOs and TKOs in MMA are higher than previously reported rates in other combative and contact sports. Public health authorities and physicians should be cognizant of the rates and mechanisms of head trauma. Preventive measures to lessen the risks of head trauma for those who elect to participate in MMA are described. © 2014 The Author(s).

Global medicine: Is it ethical or morally justifiable for doctors and other healthcare workers to go on strike?

PubMed Central

2013-01-01

Background Doctor and healthcare worker (HCW) strikes are a global phenomenon with the potential to negatively impact on the quality of healthcare services and the doctor-patient relationship. Strikes are a legitimate deadlock breaking mechanism employed when labour negotiations have reached an impasse during collective bargaining. Striking doctors usually have a moral dilemma between adherence to the Hippocratic tenets of the medical profession and fiduciary obligation to patients. In such circumstances the ethical principles of respect for autonomy, justice and beneficence all come into conflict, whereby doctors struggle with their role as ordinary employees who are rightfully entitled to a just wage for just work versus their moral obligations to patients and society. Discussion It has been argued that to deny any group of workers, including "essential workers" the right to strike is akin to enslavement which is ethically and morally indefensible. While HCW strikes occur globally, the impact appears more severe in developing countries challenged by poorer socio-economic circumstances, embedded infrastructural deficiencies, and lack of viable alternative means of obtaining healthcare. These communities appear to satisfy the criteria for vulnerability and may be deserving of special ethical consideration when doctor and HCW strikes are contemplated. Summary The right to strike is considered a fundamental right whose derogation would be inimical to the proper functioning of employer/employee collective bargaining in democratic societies. Motivations for HCW strikes include the natural pressure to fulfil human needs and the paradigm shift in modern medical practice, from self-employment and benevolent paternalism, to managed healthcare and consumer rights. Minimizing the incidence and impact of HCW strikes will require an ethical approach from all stakeholders, and recognition that all parties have an equal moral obligation to serve the best interests of society. Employers should implement legitimate collective bargaining agreements in a timely manner and high-handed actions such as mass-firing of striking HCWs, or unjustifiable disciplinary action by regulators should be avoided. Minimum service level agreements should be implemented to mitigate the impact of HCW strikes on indigent populations. Striking employees including HCWs should also desist from making unrealistic wage demands which could bankrupt governments/employers or hamper provision of other equally important social services to the general population. PMID:24564968

Precision Strike Training in Lean Manufacturing: A Workplace Literacy Guidebook [and] Final Report on Precision Strike Workplace Literacy Training at CertainTeed Corporation.

ERIC Educational Resources Information Center

National Alliance of Business, Inc., Washington, DC.

CertainTeed's Precision Strike training program was designed to close the gaps between the current status of its workplace and where that work force needed to be to compete successfully in global markets. Precision Strike included Skills and Knowledge in Lifelong Learning (SKILL) customized, computerized lessons in basic skills, one-on-one…

The Teacher Strike: School District Protection Procedures. A Manual for School District Officials on How to Handle a Teachers' Strike.

ERIC Educational Resources Information Center

Igoe, Joseph A.; DiRocco, Anthony P.

This booklet is designed to give practical and realistic advice to school district officials faced with the possibility of a teachers' strike. It is intended for use both by school district administrators and school board members. The booklet is organized into four sections that focus in turn on signs of a pending teachers' strike, union…

76 FR 19162 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

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2011-04-06

... Amend the BOX Rules To Expand the $2.50 Strike Price Program March 31, 2011. Pursuant to Section 19(b)(1..., LLC (``BOX'') to expand the $2.50 Strike Price Program. The text of the proposed rule change is... Strike Price Program (``Program'') \\4\\ to permit the listing of options with $2.50 strike price intervals...

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2010-11-03

... strike, an out-of-the-money option. However, if a $0.50 strike series had been available, the investor would have been able to control 5,000 shares by purchasing 50 exercisable in-the-money $0.50 strike call... the time was $1, an in-the-money option. If a $0.50 strike series had been available, the investor...

2005 Precision Strike Annual Programs Review

DTIC Science & Technology

2005-04-20

Control Canards (4) Polyurethane Foam Support DPICM (404 M101 Grenades) Warhead Fuze: Electronic Safe & Arm Device (ESAD) UNCLASSIFIED UNCLASSIFIED PF...SYSTEMS: • JASSM: Colonel James Geurts, USAF JASSM PM • ATACMS : Colonel Earnest Harris, USA PM, Precision Fires Rockets & Missiles, PEO Space and...UNCLASSIFIED UNCLASSIFIED Viper Strike Lineage ATACMS Delivered Base BATs Viper Strike SAL Seeker Proof of Principle Demos I & II Hunter-Viper Strike

Lower Extremity Biomechanics and Self-Reported Foot-Strike Patterns Among Runners in Traditional and Minimalist Shoes.

PubMed

Goss, Donald L; Lewek, Michael; Yu, Bing; Ware, William B; Teyhen, Deydre S; Gross, Michael T

2015-06-01

The injury incidence rate among runners is approximately 50%. Some individuals have advocated using an anterior-foot-strike pattern to reduce ground reaction forces and injury rates that they attribute to a rear-foot-strike pattern. The proportion of minimalist shoe wearers who adopt an anterior-foot-strike pattern remains unclear. To evaluate the accuracy of self-reported foot-strike patterns, compare negative ankle- and knee-joint angular work among runners using different foot-strike patterns and wearing traditional or minimalist shoes, and describe average vertical-loading rates. Descriptive laboratory study. Research laboratory. A total of 60 healthy volunteers (37 men, 23 women; age = 34.9 ± 8.9 years, height = 1.74 ± 0.08 m, mass = 70.9 ± 13.4 kg) with more than 6 months of experience wearing traditional or minimalist shoes were instructed to classify their foot-strike patterns. Participants ran in their preferred shoes on an instrumented treadmill with 3-dimensional motion capture. Self-reported foot-strike patterns were compared with 2-dimensional video assessments. Runners were classified into 3 groups based on video assessment: traditional-shoe rear-foot strikers (TSR; n = 22), minimalist-shoe anterior-foot strikers (MSA; n = 21), and minimalist-shoe rear-foot strikers (MSR; n = 17). Ankle and knee negative angular work and average vertical-loading rates during stance phase were compared among groups. Only 41 (68.3%) runners reported foot-strike patterns that agreed with the video assessment (κ = 0.42, P < .001). The TSR runners demonstrated greater ankle-dorsiflexion and knee-extension negative work than MSA and MSR runners (P < .05). The MSA (P < .001) and MSR (P = .01) runners demonstrated greater ankle plantar-flexion negative work than TSR runners. The MSR runners demonstrated a greater average vertical-loading rate than MSA and TSR runners (P < .001). Runners often cannot report their foot-strike patterns accurately and may not automatically adopt an anterior-foot-strike pattern after transitioning to minimalist running shoes.

Geology of the continental margin beneath Santa Monica Bay, Southern California, from seismic-reflection data

USGS Publications Warehouse

Fisher, M.A.; Normark, W.R.; Bohannon, R.G.; Sliter, R.W.; Calvert, A.J.

2003-01-01

We interpret seismic-reflection data, which were collected in Santa Monica Bay using a 70-in3 generator-injector air gun, to show the geologic structure of the continental shelf and slope and of the deep-water, Santa Monica and San Pedro Basins. The goal of this research is to investigate the earthquake hazard posed to urban areas by offshore faults. These data reveal that northwest of the Palos Verdes Peninsula, the Palos Verdes Fault neither offsets the seafloor nor cuts through an undeformed sediment apron that postdates the last sea level rise. Other evidence indicates that this fault extends northwest beneath the shelf in the deep subsurface. However, other major faults in the study area, such as the Dume and San Pedro Basin Faults, were active recently, as indicated by an arched seafloor and offset shallow sediment. Rocks under the lower continental slope are deformed to differing degrees on opposite sides of Santa Monica Canyon. Northwest of this canyon, the continental slope is underlain by a little-deformed sediment apron; the main structures that deform this apron are two lower-slope anticlines that extend toward Point Dume and are cored by faults showing reverse or thrust separation. Southeast of Santa Monica Canyon, lower-slope rocks are deformed by a complex arrangement of strike-slip, normal, and reverse faults. The San Pedro Escarpment rises abruptly along the southeast side of Santa Monica Canyon. Reverse faults and folds underpinning this escarpment steepen progressively southeastward. Locally they form flower structures and cut downward into basement rocks. These faults merge downward with the San Pedro Basin fault zone, which is nearly vertical and strike slip. The escarpment and its attendant structures diverge from this strike-slip fault zone and extend for 60 km along the margin, separating the continental shelf from the deep-water basins. The deep-water Santa Monica Basin has large extent but is filled with only a thin (less than 1.5-km) section of what are probably post-Miocene rocks and sediment. Extrapolating ages obtained from Ocean Drilling Program site 1015 indicates that this sedimentary cover is Quaternary, possibly no older than 600 ka. Folds and faults along the base of the San Pedro Escarpment began to form during 8-13 ka ago. Refraction-velocity data show that high-velocity rocks, probably the Catalina Schist or Miocene volcanic rocks, underlie the sedimentary section. The San Pedro Basin developed along a strike-slip fault, widens to the southeast, and is deformed by faults having apparent reverse separation and by folds near Redondo Canyon and the Palos Verdes Peninsula.

Geology of the Western Part of Los Alamos National Laboratory (TA-3 to TA-16), Rio Grande Rift, New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

C.J.Lewis; A.Lavine; S.L.Reneau

2002-12-01

We present data that elucidate the stratigraphy, geomorphology, and structure in the western part of Los Alamos National Laboratory between Technical Areas 3 and 16 (TA-3 and TA-16). Data include those gathered by geologic mapping of surficial, post-Bandelier Tuff strata, conventional and high-precision geologic mapping and geochemical analysis of cooling units within the Bandelier Tuff, logging of boreholes and a gas pipeline trench, and structural analysis using profiles, cross sections, structure contour maps, and stereographic projections. This work contributes to an improved understanding of the paleoseismic and geomorphic history of the area, which will aid in future seismic hazard evaluationsmore » and other investigations. The study area lies at the base of the main, 120-m (400-ft) high escarpment formed by the Pajarito fault, an active fault of the Rio Grande rift that bounds Los Alamos National Laboratory on the west. Subsidiary fracturing, faulting, and folding associated with the Pajarito fault zone extends at least 1,500 m (5,000 ft) to the east of the main Pajarito fault escarpment. Stratigraphic units in the study area include upper units of the Tshirege Member of the early Pleistocene Bandelier Tuff, early Pleistocene alluvial fan deposits that predate incision of canyons on this part of the Pajarito Plateau, and younger Pleistocene and Holocene alluvium and colluvium that postdate drainage incision. We discriminate four sets of structures in the area between TA-3 and TA-16: (a) north-striking faults and folds that mark the main zone of deformation, including a graben in the central part of the study area; (b) north-northwest-striking fractures and rare faults that bound the eastern side of the principal zone of deformation and may be the surface expression of deep-seated faulting; (c) rare northeast-striking structures near the northern limit of the area associated with the southern end of the Rendija Canyon fault; and (d) several small east-west-striking faults. We consider all structures to be Quaternary in that they postdate the Tshirege Member (1.22 million years old) of the Bandelier Tuff. Older mesa-top alluvial deposits (Qoal), which may have a large age range but are probably in part about 1.13 million years old, are clearly faulted or deformed by many structures. At two localities, younger alluvial units (Qfo and Qfi) appear to be truncated by faults, but field relations are obscure, and we cannot confirm the presence of fault contacts. The youngest known faulting in the study area occurred in Holocene time on a down-to-the-west fault, recently trenched at the site of a new LANL Emergency Operations Center (Reneau et al. 2002).« less

Making the Handoff from Earthquake Hazard Assessments to Effective Mitigation Measures (Invited)

NASA Astrophysics Data System (ADS)

Applegate, D.

2010-12-01

This year has witnessed a barrage of large earthquakes worldwide with the resulting damages ranging from inconsequential to truly catastrophic. We cannot predict when earthquakes will strike, but we can build communities that are resilient to strong shaking as well as to secondary hazards such as landslides and liquefaction. The contrasting impacts of the magnitude-7 earthquake that struck Haiti in January and the magnitude-8.8 event that struck Chile in April underscore the difference that mitigation and preparedness can make. In both cases, millions of people were exposed to severe shaking, but deaths in Chile were measured in the hundreds rather than the hundreds of thousands that perished in Haiti. Numerous factors contributed to these disparate outcomes, but the most significant is the presence of strong building codes in Chile and their total absence in Haiti. The financial cost of the Chilean earthquake still represents an unacceptably high percentage of that nation’s gross domestic product, a reminder that life safety is the paramount, but not the only, goal of disaster risk reduction measures. For building codes to be effective, both in terms of lives saved and economic cost, they need to reflect the hazard as accurately as possible. As one of four federal agencies that make up the congressionally mandated National Earthquake Hazards Reduction Program (NEHRP), the U.S. Geological Survey (USGS) develops national seismic hazard maps that form the basis for seismic provisions in model building codes through the Federal Emergency Management Agency and private-sector practitioners. This cooperation is central to NEHRP, which both fosters earthquake research and establishes pathways to translate research results into implementation measures. That translation depends on the ability of hazard-focused scientists to interact and develop mutual trust with risk-focused engineers and planners. Strengthening that interaction is an opportunity for the next generation of earthquake scientists and engineers. In addition to the national maps, the USGS produces more detailed urban seismic hazard maps that communities have used to prioritize retrofits and design critical infrastructure that can withstand large earthquakes. At a regional scale, the USGS and its partners in California have developed a time-dependent earthquake rupture forecast that is being used by the insurance sector, which can serve to distribute risk and foster mitigation if the right incentives are in place. What the USGS and partners are doing at the urban, regional, and national scales, the Global Earthquake Model project is seeking to do for the world. A significant challenge for engaging the public to prepare for earthquakes is making low-probability, high-consequence events real enough to merit personal action. Scenarios help by starting with the hazard posed by a specific earthquake and then exploring the fragility of the built environment, cascading failures, and the real-life consequences for the public. To generate such a complete picture takes multiple disciplines working together. Earthquake scenarios are being used both for emergency management exercises and much broader public preparedness efforts like the Great California ShakeOut, which engaged nearly 7 million people.

Variation in Foot Strike Patterns during Running among Habitually Barefoot Populations

PubMed Central

Hatala, Kevin G.; Dingwall, Heather L.; Wunderlich, Roshna E.; Richmond, Brian G.

2013-01-01

Endurance running may have a long evolutionary history in the hominin clade but it was not until very recently that humans ran wearing shoes. Research on modern habitually unshod runners has suggested that they utilize a different biomechanical strategy than runners who wear shoes, namely that barefoot runners typically use a forefoot strike in order to avoid generating the high impact forces that would be experienced if they were to strike the ground with their heels first. This finding suggests that our habitually unshod ancestors may have run in a similar way. However, this research was conducted on a single population and we know little about variation in running form among habitually barefoot people, including the effects of running speed, which has been shown to affect strike patterns in shod runners. Here, we present the results of our investigation into the selection of running foot strike patterns among another modern habitually unshod group, the Daasanach of northern Kenya. Data were collected from 38 consenting adults as they ran along a trackway with a plantar pressure pad placed midway along its length. Subjects ran at self-selected endurance running and sprinting speeds. Our data support the hypothesis that a forefoot strike reduces the magnitude of impact loading, but the majority of subjects instead used a rearfoot strike at endurance running speeds. Their percentages of midfoot and forefoot strikes increased significantly with speed. These results indicate that not all habitually barefoot people prefer running with a forefoot strike, and suggest that other factors such as running speed, training level, substrate mechanical properties, running distance, and running frequency, influence the selection of foot strike patterns. PMID:23326341

Foot strike patterns after obstacle clearance during running.

PubMed

Scholten, Shane D; Stergiou, Nicholas; Hreljac, Alan; Houser, Jeremy; Blanke, Daniel; Alberts, L Russell

2002-01-01

Running over obstacles of sufficient height requires heel strike (HS) runners to make a transition in landing strategy to a forefoot (FF) strike, resulting in similar ground reaction force patterns to those observed while landing from a jump. Identification of the biomechanical variables that distinguish between the landing strategies may offer some insight into the reasons that the transition occurs. The purpose of this study was to investigate the difference in foot strike patterns and kinetic parameters of heel strike runners between level running and running over obstacles of various heights. Ten heel strike subjects ran at their self-selected pace under seven different conditions: unperturbed running (no obstacle) and over obstacles of six different heights (10%, 12.5%, 15%, 17.5%, 20%, and 22.5% of their standing height). The obstacle was placed directly before a Kistler force platform. Repeated measures ANOVAs were performed on the subject means of selected kinetic parameters. The statistical analysis revealed significant differences (P < 0.004) for all of the parameters analyzed. The evaluation of the center of pressure and the ground reaction forces indicated that the foot strike patterns were affected by the increased obstacle height. Between the 12.5% and 15% obstacle conditions, the group response changed from a heel strike to a forefoot strike pattern. At height > 15%, the pattern was more closely related to the foot strike patterns found in jumping activities. This strategy change may represent a gait transition effected as a mechanism to protect against increased impact forces. Greater involvement of the ankle and the calf muscles could have assisted in attenuating the increased impact forces while maintaining speed after clearing the obstacle.

Variation in foot strike patterns during running among habitually barefoot populations.

PubMed

Hatala, Kevin G; Dingwall, Heather L; Wunderlich, Roshna E; Richmond, Brian G

2013-01-01

Endurance running may have a long evolutionary history in the hominin clade but it was not until very recently that humans ran wearing shoes. Research on modern habitually unshod runners has suggested that they utilize a different biomechanical strategy than runners who wear shoes, namely that barefoot runners typically use a forefoot strike in order to avoid generating the high impact forces that would be experienced if they were to strike the ground with their heels first. This finding suggests that our habitually unshod ancestors may have run in a similar way. However, this research was conducted on a single population and we know little about variation in running form among habitually barefoot people, including the effects of running speed, which has been shown to affect strike patterns in shod runners. Here, we present the results of our investigation into the selection of running foot strike patterns among another modern habitually unshod group, the Daasanach of northern Kenya. Data were collected from 38 consenting adults as they ran along a trackway with a plantar pressure pad placed midway along its length. Subjects ran at self-selected endurance running and sprinting speeds. Our data support the hypothesis that a forefoot strike reduces the magnitude of impact loading, but the majority of subjects instead used a rearfoot strike at endurance running speeds. Their percentages of midfoot and forefoot strikes increased significantly with speed. These results indicate that not all habitually barefoot people prefer running with a forefoot strike, and suggest that other factors such as running speed, training level, substrate mechanical properties, running distance, and running frequency, influence the selection of foot strike patterns.

The Distribution of Cloud to Ground Lightning Strike Intensities and Associated Magnetic Inductance Fields Near the Kennedy Space Center

NASA Technical Reports Server (NTRS)

Burns, Lee; Decker, Ryan

2005-01-01

Lightning strike location and peak current are monitored operationally in the Kennedy Space Center (KSC) Cape Canaveral Air Force Station (CCAFS) area by the Cloud to Ground Lightning Surveillance System (CGLSS). The present study compiles ten years worth of CGLSS data into a database of near strikes. Using shuffle launch platform LP39A as a convenient central point, all strikes recorded within a 20-mile radius for the period of record O R ) from January 1, 1993 to December 31,2002 were included in the subset database. Histograms and cumulative probability curves are produced for both strike intensity (peak current, in kA) and the corresponding magnetic inductance fields (in A/m). Results for the full POR have application to launch operations lightning monitoring and post-strike test procedures.

Power electromagnetic strike machine for engineering-geological surveys

NASA Astrophysics Data System (ADS)

Usanov, K. M.; Volgin, A. V.; Chetverikov, E. A.; Kargin, V. A.; Moiseev, A. P.; Ivanova, Z. I.

2017-10-01

When implementing the processes of dynamic sensing of soils and pulsed nonexplosive seismic exploration, the most common and effective method is the strike one, which is provided by a variety of structure and parameters of pneumatic, hydraulic, electrical machines of strike action. The creation of compact portable strike machines which do not require transportation and use of mechanized means is important. A promising direction in the development of strike machines is the use of pulsed electromagnetic actuator characterized by relatively low energy consumption, relatively high specific performance and efficiency, and providing direct conversion of electrical energy into mechanical work of strike mass with linear movement trajectory. The results of these studies allowed establishing on the basis of linear electromagnetic motors the electromagnetic pulse machines with portable performance for dynamic sensing of soils and land seismic pulse of small depths.

Probabilistic seismic hazard analysis for Sumatra, Indonesia and across the Southern Malaysian Peninsula

USGS Publications Warehouse

Petersen, M.D.; Dewey, J.; Hartzell, S.; Mueller, C.; Harmsen, S.; Frankel, A.D.; Rukstales, K.

2004-01-01

The ground motion hazard for Sumatra and the Malaysian peninsula is calculated in a probabilistic framework, using procedures developed for the US National Seismic Hazard Maps. We constructed regional earthquake source models and used standard published and modified attenuation equations to calculate peak ground acceleration at 2% and 10% probability of exceedance in 50 years for rock site conditions. We developed or modified earthquake catalogs and declustered these catalogs to include only independent earthquakes. The resulting catalogs were used to define four source zones that characterize earthquakes in four tectonic environments: subduction zone interface earthquakes, subduction zone deep intraslab earthquakes, strike-slip transform earthquakes, and intraplate earthquakes. The recurrence rates and sizes of historical earthquakes on known faults and across zones were also determined from this modified catalog. In addition to the source zones, our seismic source model considers two major faults that are known historically to generate large earthquakes: the Sumatran subduction zone and the Sumatran transform fault. Several published studies were used to describe earthquakes along these faults during historical and pre-historical time, as well as to identify segmentation models of faults. Peak horizontal ground accelerations were calculated using ground motion prediction relations that were developed from seismic data obtained from the crustal interplate environment, crustal intraplate environment, along the subduction zone interface, and from deep intraslab earthquakes. Most of these relations, however, have not been developed for large distances that are needed for calculating the hazard across the Malaysian peninsula, and none were developed for earthquake ground motions generated in an interplate tectonic environment that are propagated into an intraplate tectonic environment. For the interplate and intraplate crustal earthquakes, we have applied ground-motion prediction relations that are consistent with California (interplate) and India (intraplate) strong motion data that we collected for distances beyond 200 km. For the subduction zone equations, we recognized that the published relationships at large distances were not consistent with global earthquake data that we collected and modified the relations to be compatible with the global subduction zone ground motions. In this analysis, we have used alternative source and attenuation models and weighted them to account for our uncertainty in which model is most appropriate for Sumatra or for the Malaysian peninsula. The resulting peak horizontal ground accelerations for 2% probability of exceedance in 50 years range from over 100% g to about 10% g across Sumatra and generally less than 20% g across most of the Malaysian peninsula. The ground motions at 10% probability of exceedance in 50 years are typically about 60% of the ground motions derived for a hazard level at 2% probability of exceedance in 50 years. The largest contributors to hazard are from the Sumatran faults.

An Inverse Kinematic Approach Using Groebner Basis Theory Applied to Gait Cycle Analysis

DTIC Science & Technology

2013-03-01

stance phase begins with initial contact, heel strike , and ends with toe off. The swing phase begins at toe off and ends with the heel striking the ground...and transition phase (10%). Recall, that the gait cycle begins when the heel strikes the ground of one foot and ends when that same foot strikes the...Validation of Knee Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 12 Validation of Ankle Angle

Independent effects of step length and foot strike pattern on tibiofemoral joint forces during running.

PubMed

Bowersock, Collin D; Willy, Richard W; DeVita, Paul; Willson, John D

2017-10-01

The purpose of this study was to examine the effects of step length and foot strike pattern along with their interaction on tibiofemoral joint (TFJ) and medial compartment TFJ kinetics during running. Nineteen participants ran with a rear foot strike pattern at their preferred speed using a short (-10%), preferred, and long (+10%) step length. These step length conditions were then repeated using a forefoot strike pattern. Regardless of foot strike pattern, a 10% shorter step length resulted in decreased peak contact force, force impulse per step, force impulse per kilometre, and average loading rate at the TFJ and medial compartment, while a 10% increased step length had the opposite effects (all P < 0.05). A forefoot strike pattern significantly lowered TFJ and medial compartment TFJ average loading rates compared with a rear foot strike pattern (both <0.05) but did not change TFJ or medial compartment peak force, force impulse per step, or force impulse per km. The combination of a shorter step length and forefoot strike pattern produced the greatest reduction in peak medial compartment contact force (P < 0.05). Knowledge of these running modification effects may be relevant to the management or prevention of TFJ injury or pathology among runners.

Site-to-Source Finite Fault Distance Probability Distribution in Probabilistic Seismic Hazard and the Relationship Between Minimum Distances

NASA Astrophysics Data System (ADS)

Ortega, R.; Gutierrez, E.; Carciumaru, D. D.; Huesca-Perez, E.

2017-12-01

We present a method to compute the conditional and no-conditional probability density function (PDF) of the finite fault distance distribution (FFDD). Two cases are described: lines and areas. The case of lines has a simple analytical solution while, in the case of areas, the geometrical probability of a fault based on the strike, dip, and fault segment vertices is obtained using the projection of spheres in a piecewise rectangular surface. The cumulative distribution is computed by measuring the projection of a sphere of radius r in an effective area using an algorithm that estimates the area of a circle within a rectangle. In addition, we introduce the finite fault distance metrics. This distance is the distance where the maximum stress release occurs within the fault plane and generates a peak ground motion. Later, we can apply the appropriate ground motion prediction equations (GMPE) for PSHA. The conditional probability of distance given magnitude is also presented using different scaling laws. A simple model of constant distribution of the centroid at the geometrical mean is discussed, in this model hazard is reduced at the edges because the effective size is reduced. Nowadays there is a trend of using extended source distances in PSHA, however it is not possible to separate the fault geometry from the GMPE. With this new approach, it is possible to add fault rupture models separating geometrical and propagation effects.

Guidelines for the selection of chemical-protective clothing. Volume 2. Technical and reference manual. (3rd Edition). Report for January 1985-March 1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwope, A.D.; Costas, P.P.; Jackson, J.O.

1987-02-01

A variety of protective-clothing items are commercially available for emergency response and other applications where chemical hazards may be encountered. Data and information for selecting chemical-protective clothing is either not available or is inconsistant from source to source. In 1983, the U.S. Environmental Protection Agency sponsored the development of chemical-protective clothing selection guidelines to assist their own Office of Health and Safety in providing guidance to personnel, primarily EPA employees and contractors, working on hazardous-waste sites. These guidelines allowed a user to select an appropriate protective material for a specific chemical, select a clothing item (glove, suit, etc.), and thenmore » determine which manufacturers offered the clothing item in the recommended material. The U.S, Coast Guard Office of Research and Development and the EPA have supplemented these guidelines with additional data on material chemical resistance, material physical properties, clothing design features, and specific-vendor products. A chapter has been added for selecting chemical-protective suits. These guidelines contain data for over 750 chemicals and 700 clothing products. Volume I provides performance information and recommendations for selecting different types of protective clothing. Volume II contains a detailed technical discussion, and the data on which Volume I recommendations are based. The U.S. Coast Guard intends to use these guidelines for protective-clothing selection by its National Strike Force and Marine Safety Offices.« less

Geology, tephrochronology, radiometric ages, and cross sections of the Mark West Springs 7.5' quadrangle, Sonoma and Napa counties, California

USGS Publications Warehouse

McLaughlin, R.J.; Sarna-Wojicki, A. M.; Fleck, R.J.; Wright, W.H.; Levin, V.R.G.; Valin, Z.C.

2004-01-01

The purpose of this geologic map is to provide a context within which to interpret the Neogene evolution of the active strike-slip fault system traversing the Mark West Springs 7.5' quadrangle and adjacent areas. Based on this geologic framework, the timing and total amounts of displacement and the Neogene rates of slip for faults of the right-stepover area between the Healdsburg and Maacama Faults are addressed.The Mark West Springs quadrangle is located in the northern California Coast Ranges north of San Francisco Bay. It is underlain by Mesozoic rocks of the Franciscan Complex, the Coast Range ophiolite, and the Great Valley sequence, considered here to be the pre-Tertiary basement of the northern Coast Ranges. These rocks are overlain by a complexly interstratified and mildly to moderately deformed sequence of Pleistocene to late Miocene marine and nonmarine sedimentary and largely subaerial volcanic rocks. These rocks and unconformably overlying, less-deformed Holocene and Pleistocene strata are cut by the active right-lateral Healdsburg and Maacama Fault Zones.Mapping of the Mark West Springs quadrangle began in 1996 and was completed in October 2002. Most of the mapping presented here is original, although a few other sources of existing geologic mapping were also utilized. Funding for the project was provided by the National Cooperative Geologic Mapping and Earthquake Hazards Reduction programs of the U.S. Geological Survey, in cooperation with geologic hazards mapping investigations of the California Geological Survey.

Monte Carlo Method for Determining Earthquake Recurrence Parameters from Short Paleoseismic Catalogs: Example Calculations for California

USGS Publications Warehouse

Parsons, Tom

2008-01-01

Paleoearthquake observations often lack enough events at a given site to directly define a probability density function (PDF) for earthquake recurrence. Sites with fewer than 10-15 intervals do not provide enough information to reliably determine the shape of the PDF using standard maximum-likelihood techniques [e.g., Ellsworth et al., 1999]. In this paper I present a method that attempts to fit wide ranges of distribution parameters to short paleoseismic series. From repeated Monte Carlo draws, it becomes possible to quantitatively estimate most likely recurrence PDF parameters, and a ranked distribution of parameters is returned that can be used to assess uncertainties in hazard calculations. In tests on short synthetic earthquake series, the method gives results that cluster around the mean of the input distribution, whereas maximum likelihood methods return the sample means [e.g., NIST/SEMATECH, 2006]. For short series (fewer than 10 intervals), sample means tend to reflect the median of an asymmetric recurrence distribution, possibly leading to an overestimate of the hazard should they be used in probability calculations. Therefore a Monte Carlo approach may be useful for assessing recurrence from limited paleoearthquake records. Further, the degree of functional dependence among parameters like mean recurrence interval and coefficient of variation can be established. The method is described for use with time-independent and time-dependent PDF?s, and results from 19 paleoseismic sequences on strike-slip faults throughout the state of California are given.

Monte Carlo method for determining earthquake recurrence parameters from short paleoseismic catalogs: Example calculations for California

USGS Publications Warehouse

Parsons, T.

2008-01-01

Paleoearthquake observations often lack enough events at a given site to directly define a probability density function (PDF) for earthquake recurrence. Sites with fewer than 10-15 intervals do not provide enough information to reliably determine the shape of the PDF using standard maximum-likelihood techniques (e.g., Ellsworth et al., 1999). In this paper I present a method that attempts to fit wide ranges of distribution parameters to short paleoseismic series. From repeated Monte Carlo draws, it becomes possible to quantitatively estimate most likely recurrence PDF parameters, and a ranked distribution of parameters is returned that can be used to assess uncertainties in hazard calculations. In tests on short synthetic earthquake series, the method gives results that cluster around the mean of the input distribution, whereas maximum likelihood methods return the sample means (e.g., NIST/SEMATECH, 2006). For short series (fewer than 10 intervals), sample means tend to reflect the median of an asymmetric recurrence distribution, possibly leading to an overestimate of the hazard should they be used in probability calculations. Therefore a Monte Carlo approach may be useful for assessing recurrence from limited paleoearthquake records. Further, the degree of functional dependence among parameters like mean recurrence interval and coefficient of variation can be established. The method is described for use with time-independent and time-dependent PDFs, and results from 19 paleoseismic sequences on strike-slip faults throughout the state of California are given.

Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues

DTIC Science & Technology

2012-07-06

Missiles Congressional Research Service Forward-Based Global Strike ( FBGS ...Congressional Research Service 36 Forward-Based Global Strike ( FBGS ) Analysts have also explored the option of deploying long-range land-based

Is the rearfoot pattern the most frequently foot strike pattern among recreational shod distance runners?

PubMed

de Almeida, Matheus Oliveira; Saragiotto, Bruno Tirotti; Yamato, Tiê Parma; Lopes, Alexandre Dias

2015-02-01

To determine the distribution of the foot strike patterns among recreational shod runners and to compare the personal and training characteristics between runners with different foot strike patterns. Cross-sectional study. Areas of running practice in São Paulo, Brazil. 514 recreational shod runners older than 18 years and free of injury. Foot strike patterns were evaluated with a high-speed camera (250 Hz) and photocells to assess the running speed of participants. Personal and training characteristics were collected through a questionnaire. The inter-rater reliability of the visual foot strike pattern classification method was 96.7% and intra-rater reliability was 98.9%. 95.1% (n = 489) of the participants were rearfoot strikers, 4.1% (n = 21) were midfoot strikers, and four runners (0.8%) were forefoot strikers. There were no significant differences between strike patterns for personal and training characteristics. This is the first study to demonstrate that almost all recreational shod runners were rearfoot strikers. The visual method of evaluation seems to be a reliable and feasible option to classify foot strike pattern. Copyright © 2014 Elsevier Ltd. All rights reserved.

Launch pad lightning protection effectiveness

NASA Technical Reports Server (NTRS)

Stahmann, James R.

1991-01-01

Using the striking distance theory that lightning leaders will strike the nearest grounded point on their last jump to earth corresponding to the striking distance, the probability of striking a point on a structure in the presence of other points can be estimated. The lightning strokes are divided into deciles having an average peak current and striking distance. The striking distances are used as radii from the points to generate windows of approach through which the leader must pass to reach a designated point. The projections of the windows on a horizontal plane as they are rotated through all possible angles of approach define an area that can be multiplied by the decile stroke density to arrive at the probability of strokes with the window average striking distance. The sum of all decile probabilities gives the cumulative probability for all strokes. The techniques can be applied to NASA-Kennedy launch pad structures to estimate the lightning protection effectiveness for the crane, gaseous oxygen vent arm, and other points. Streamers from sharp points on the structure provide protection for surfaces having large radii of curvature. The effects of nearby structures can also be estimated.

Structural setting and kinematics of Nubian fault system, SE Western Desert, Egypt: An example of multi-reactivated intraplate strike-slip faults

NASA Astrophysics Data System (ADS)

Sakran, Shawky; Said, Said Mohamed

2018-02-01

Detailed surface geological mapping and subsurface seismic interpretation have been integrated to unravel the structural style and kinematic history of the Nubian Fault System (NFS). The NFS consists of several E-W Principal Deformation Zones (PDZs) (e.g. Kalabsha fault). Each PDZ is defined by spectacular E-W, WNW and ENE dextral strike-slip faults, NNE sinistral strike-slip faults, NE to ENE folds, and NNW normal faults. Each fault zone has typical self-similar strike-slip architecture comprising multi-scale fault segments. Several multi-scale uplifts and basins were developed at the step-over zones between parallel strike-slip fault segments as a result of local extension or contraction. The NNE faults consist of right-stepping sinistral strike-slip fault segments (e.g. Sin El Kiddab fault). The NNE sinistral faults extend for long distances ranging from 30 to 100 kms and cut one or two E-W PDZs. Two nearly perpendicular strike-slip tectonic regimes are recognized in the NFS; an inactive E-W Late Cretaceous - Early Cenozoic dextral transpression and an active NNE sinistral shear.

Interseismic Coupling on the Quito Fault System in Ecuador Using New GPS and InSAR Data and Its Implication on Seismic Hazard Assessment.

NASA Astrophysics Data System (ADS)

Mariniere, J.; Champenois, J.; Nocquet, J. M.; Beauval, C. M.; Audin, L.; Baize, S.; Alvarado, A. P.; Yepes, H. A.; Jomard, H.

2017-12-01

Quito, the capital of Ecuador hosting two million inhabitants lies on an active reverse fault system within the Andes. Regular moderate size earthquakes (M 5) occur on these faults, widely felt within the city and its surrounding. Despite a relatively small magnitude of Mw 5.1, the 2014 August 12 earthquake triggered landslides that killed 4 people, cut off one of the main highways for several weeks and caused the temporary shutdown of the airport. Quantifying the seismic potential of the Quito fault system is therefore crucial for a better preparation and mitigation to seismic risk. Previous work using a limited GPS data set found that the Quito fault accommodates 4 mm/yr of EW shortening (Alvarado et al., 2014) at shallow locking depths (3-7 km). We combine GPS and new InSAR data to extend the previous analysis and better quantify the spatial distribution of locking of the Quito fault. GPS dataset includes new continuous sites operating since 2013. 18 ERS SAR scenes, spanning the 1993-2000 time period and covering an area of 85 km by 30 km, were processed using a Permanent Scatter strategy. We perform a joint inversion of both data set (GPS and InSAR) to infer a new and better-constrained kinematic model of the fault to determine both the slip rate and the locking distribution at depth. We find a highly variable level of locking which changes along strike. At some segments, sharp displacement gradients observed both for GPS and InSAR suggest that the fault is creeping up to the surface, while shallow locking is found for other segments. Previous Probabilistic Seismic Hazard Assessment studies have shown that the Quito fault fully controls the hazard in Quito city (Beauval et al. 2014). The results will be used to improve the forecast of earthquakes on the Quito fault system for PSHA studies.

The Olmsted fault zone, southernmost Illinois: A key to understanding seismic hazard in the northern new Madrid seismic zone

USGS Publications Warehouse

Bexfield, C.E.; McBride, J.H.; Pugin, Andre J.M.; Nelson, W.J.; Larson, T.H.; Sargent, S.L.

2005-01-01

Geological deformation in the northern New Madrid seismic zone, near Olmsted, Illinois (USA), is analyzed using integrated compressional-wave (P) and horizontally polarized-wave (SH) seismic reflection and regional and dedicated borehole information. Seismic hazards are of special concern because of strategic facilities (e.g., lock and dam sites and chemical plants on the Ohio River near its confluence with the Mississippi River) and because of alluvial soils subject to high amplification of earthquake shock. We use an integrated approach starting with lower resolution, but deeper penetration, P-wave reflection profiles to identify displacement of Paleozoic bedrock. Higher resolution, but shallower penetration, SH-wave images show deformation that has propagated upward from bedrock faults into Pleistocene loess. We have mapped an intricate zone more than 8 km wide of high-angle faults in Mississippi embayment sediments localized over Paleozoic bedrock faults that trend north to northeast, parallel to the Ohio River. These faults align with the pattern of epicenters in the New Madrid seismic zone. Normal and reverse offsets along with positive flower structures imply a component of strike-slip; the current stress regime favors right-lateral slip on northeast-trending faults. The largest fault, the Olmsted fault, underwent principal displacement near the end of the Cretaceous Period 65 to 70 million years ago. Strata of this age (dated via fossil pollen) thicken greatly on the downthrown side of the Olmsted fault into a locally subsiding basin. Small offsets of Tertiary and Quaternary strata are evident on high-resolution SH-wave seismic profiles. Our results imply recent reactivation and possible future seismic activity in a critical area of the New Madrid seismic zone. This integrated approach provides a strategy for evaluating shallow seismic hazard-related targets for engineering concerns. ?? 2005 Elsevier B.V. All rights reserved.

New Criterion and Tool for Caltrans Seismic Hazard Characterization

NASA Astrophysics Data System (ADS)

Shantz, T.; Merriam, M.; Turner, L.; Chiou, B.; Liu, X.

2008-12-01

Caltrans recently adopted new procedures for the development of response spectra for structure design. These procedures incorporate both deterministic and probabilistic criteria. The Next Generation Attenuation (NGA) models (2008) are used for deterministic assessment (using a revised late-Quaternary age fault database), and the USGS 2008 5% in 50-year hazard maps are used for probabilistic assessment. A minimum deterministic spectrum based on a M6.5 earthquake at 12 km is also included. These spectra are enveloped and the largest values used. A new publicly available web-based design tool for calculating the design spectrum will be used for calculations. The tool is built on a Windows-Apache-MySQL-PHP (WAMP) platform and integrates GoogleMaps for increased flexibility in the tool's use. Links to Caltrans data such as pre-construction logs of test borings assist in the estimation of Vs30 values used in the new procedures. Basin effects based on new models developed for the CFM, for the San Francisco Bay area by the USGS, and by Thurber (2008) are also incorporated. It is anticipated that additional layers such as CGS Seismic Hazard Zone maps will be added in the future. Application of the new criterion will result in expected higher levels of ground motion at many bridges west of the Coast Ranges. In eastern California, use of the NGA relationships for strike-slip faulting (the dominant sense of motion in California) will often result in slightly lower expected values for bridges. The expected result is a more realistic prediction of ground motions at bridges, in keeping with those motions developed for other large-scale and important structures. The tool is based on a simplified fault map of California, so it will not be used for more detailed evaluations such as surface rupture determination. Announcements regarding tool availability (expected to be in early 2009) are at http://www.dot.ca.gov/research/index.htm

Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues

DTIC Science & Technology

2012-02-13

Ballistic Missiles Congressional Research Service Forward-Based Global Strike ( FBGS ...missiles in the CPGS program. Forward-Based Global Strike ( FBGS ) Analysts have also explored the option of deploying long-range land-based ballistic

The 1983 direct strike lightning data, part 1

NASA Technical Reports Server (NTRS)

Thomas, Mitchel E.

1985-01-01

Data waveforms are presented which were obtained during the 1983 direct strike lightning tests utilizing the NASA F106-B aircraft specially instrumented for lightning electromagnetic measurements. The aircraft was operated in the vicinity of the NASA Langley Research Center, Hampton, Virginia, in a thunderstorm environment to elicit strikes. Electromagnetic field data and conduction currents on the aircraft were recorded for attached lightning. Part 1 contains 435 pages of lightning strike data in chart form.

The 1983 direct strike lightning data, part 2

NASA Technical Reports Server (NTRS)

Thomas, Mitchel E.

1985-01-01

Data waveforms are presented which were obtained during the 1983 direct strike lightning tests utilizing the NASA F106-B aircraft specially instrumented for lightning electromagnetic measurements. The aircraft was operated in the vicinity of the NASA Langley Research Center, Hampton, Virginia, in a thunderstorm environment to elicit strikes. Electromagnetic field data and conduction currents on the aircraft were recorded for attached lightning. Part 2 contains 443 pages of lightning strike data in chart form.

Strike action electromagnetic machine for immersion of rod elements into ground

NASA Astrophysics Data System (ADS)

Usanov, K. M.; Volgin, A. V.; Chetverikov, E. A.; Kargin, V. A.; Moiseev, A. P.; Ivanova, Z. I.

2017-10-01

During construction, survey work, and drilling shallow wells by striking, operations associated with dipping and removing the rod elements are the most common. At the same time relatively long, with small diameter, elements, in which the ratio of length to diameter l/d is 100 or more, constitute a significant proportion. At present, the application of power pulse linear electromagnetic motors to drive drum machines is recognized to be highly effective. However, the mechanical method of transmission of shocks does not allow dipping long longitudinally unstable core elements. In this case, mechanical energy must be transferred from the motor to the rod through its side surface. The design of the strike action electromagnetic machine with a through axial channel for non-mechanical end striking of the pile of long, longitudinally unstable metal rods is proposed. Electromagnetic striking machine for non-mechanical end striking rod elements provides operations characterized by ecological compatibility, safety and high quality.

Strike kinematics and performance in juvenile ball pythons (Python regius).

PubMed

Ryerson, William G; Tan, Weimin

2017-08-01

The rapid strike of snakes has interested researchers for decades. Although most work has focused on the strike performance of vipers, recent work has shown that other snakes outside of the Viperidae can strike with the same velocities and accelerations. However, to date all of these examples focus on performance in adult snakes. Here, we use high-speed video to measure the strike kinematics and performance of 10 juvenile (<6 months of age) ball pythons, Python regius. We find that juvenile P. regius strike at levels comparable to larger snakes, but with shorter durations and over shorter distances. We conclude that the juvenile P. regius maintain performance likely through manipulation of the axial musculature and accompanying elastic tissues, and that this is a first step to understanding ontogenetic changes in behavior and a potential avenue for understanding how captivity may also impact behavior. © 2017 Wiley Periodicals, Inc.

The origin of strike-slip tectonics in continental rifts

NASA Astrophysics Data System (ADS)

Ebinger, C. J.; Pagli, C.; Yun, S. H.; Keir, D.; Wang, H.

2016-12-01

Although continental rifts are zones of lithospheric extension, strike-slip tectonics is also accommodated within rifts and its origin remains controversial. Here we present a combined analysis of recent seismicity, InSAR and GPS derived strain maps to reveal that the plate motion in Afar is accommodated primarily by extensional tectonics in all rift arms and lacks evidences of regional scale bookshelf tectonics. However in the rifts of central Afar we identify crustal extension and normal faulting in the central part of the rifts but strike-slip earthquakes at the rift tips. We investigate if strike-slip can be the result of Coulomb stress changes induced by recent dyking but models do not explain these earthquakes. Instead we explain strike-slips as shearing at the tips of a broad zone of spreading where extension terminates against unstretched lithosphere. Our results demonstrate that plate spreading can develop both strike-slip and extensional tectonics in the same rifts.

Risk Considerations of Bird Strikes to Space Launch Vehicles

NASA Technical Reports Server (NTRS)

Hales, Christy; Ring, Robert

2016-01-01

Within seconds after liftoff of the Space Shuttle during mission STS-114, a turkey vulture impacted the vehicle's external tank. The contact caused no apparent damage to the Shuttle, but the incident led NASA to consider the potential consequences of bird strikes during a Shuttle launch. The environment at Kennedy Space Center provides unique bird strike challenges due to the Merritt Island National Wildlife Refuge and the Atlantic Flyway bird migration routes. NASA is currently refining risk assessment estimates for the probability of bird strike to space launch vehicles. This paper presents an approach for analyzing the risks of bird strikes to space launch vehicles and presents an example. The migration routes, types of birds present, altitudes of those birds, exposed area of the launch vehicle, and its capability to withstand impacts affect the risk due to bird strike. A summary of significant risk contributors is discussed.

Locally advanced pancreatic cancer: association between prolonged preoperative treatment and lymph-node negativity and overall survival.

PubMed

Kadera, Brian E; Sunjaya, Dharma B; Isacoff, William H; Li, Luyi; Hines, O Joe; Tomlinson, James S; Dawson, David W; Rochefort, Matthew M; Donald, Graham W; Clerkin, Barbara M; Reber, Howard A; Donahue, Timothy R

2014-02-01

Treatment of patients with locally advanced/borderline resectable (LA/BR) pancreatic ductal adenocarcinoma (PDAC) is not standardized. To (1) perform a detailed survival analysis of our institution's experience with patients with LA/BR PDAC who were downstaged and underwent surgical resection and (2) identify prognostic biomarkers that may help to guide a decision for the use of adjuvant therapy in this patient subgroup. Retrospective observational study of 49 consecutive patients from a single institution during 1992-2011 with American Joint Committee on Cancer stage III LA/BR PDAC who were initially unresectable, as determined by staging computed tomography and/or surgical exploration, and who were treated and then surgically resected. Clinicopathologic variables and prognostic biomarkers SMAD4, S100A2, and microRNA-21 were correlated with survival by univariate and multivariate Cox proportional hazard modeling. All 49 patients were deemed initially unresectable owing to vascular involvement. After completing preoperative chemotherapy for a median of 7.1 months (range, 5.4-9.6 months), most (75.5%) underwent a pylorus-preserving Whipple operation; 3 patients (6.1%) had a vascular resection. Strikingly, 37 of 49 patients were lymph-node (LN) negative (75.5%) and 42 (85.7%) had negative margins; 45.8% of evaluable patients achieved a complete histopathologic (HP) response. The median overall survival (OS) was 40.1 months (range, 22.7-65.9 months). A univariate analysis of HP prognostic biomarkers revealed that perineural invasion (hazard ratio, 5.5; P=.007) and HP treatment response (hazard ratio, 9.0; P=.009) were most significant. Lymph-node involvement, as a marker of systemic disease, was also significant on univariate analysis (P=.05). Patients with no LN involvement had longer OS (44.4 vs 23.2 months, P=.04) than LN-positive patients. The candidate prognostic biomarkers, SMAD4 protein loss (P=.01) in tumor cells and microRNA-21 expression in the stroma (P=.05), also correlated with OS. On multivariate Cox proportional hazard modeling of HP and prognostic biomarkers, only SMAD4 protein loss was significant (hazard ratio, 9.3; P=.004). Our approach to patients with LA/BR PDAC, which includes prolonged preoperative chemotherapy, is associated with a high incidence of LN-negative disease and excellent OS. After surgical resection, HP treatment response, perineural invasion, and SMAD4 status should help determine who should receive adjuvant therapy in this select subset of patients.

Surface Creep Rate and Moment Accumulation Rate Along the Aceh Segment of the Sumatran Fault From L-band ALOS-1/PALSAR-1 Observations

NASA Astrophysics Data System (ADS)

Tong, X.; Sandwell, D. T.; Schmidt, D. A.

2018-04-01

We analyzed the interferometric synthetic aperture radar data from the ALOS-1/PALSAR-1 satellite to image the interseismic deformation along the Sumatran fault. The interferometric synthetic aperture radar time series analysis reveals up to 20 mm/year of aseismic creep on the Aceh segment along the Northern Sumatran fault. This is a large fraction of the total slip rate across this fault. The spatial extent of the aseismic creep extends for 100 km. The along-strike variation of the aseismic creep has an inverse "U" shape. An analysis of the moment accumulation rate shows that the central part of the creeping section accumulates moment at approximately 50% of the rate of the surrounding locked segments. An initial analysis of temporal variations suggests that the creep rate may be decelerating with time, suggesting that the creep rate is adjusting to a stress perturbation from nearby seismic activity. Our study has implications to the earthquake hazard along the northern Sumatran fault.

Variations in creep rate along the Hayward Fault, California, interpreted as changes in depth of creep

USGS Publications Warehouse

Simpson, R.W.; Lienkaemper, J.J.; Galehouse, J.S.

2001-01-01

Variations ill surface creep rate along the Hayward fault are modeled as changes in locking depth using 3D boundary elements. Model creep is driven by screw dislocations at 12 km depth under the Hayward and other regional faults. Inferred depth to locking varies along strike from 4-12 km. (12 km implies no locking.) Our models require locked patches under the central Hayward fault, consistent with a M6.8 earthquake in 1868, but the geometry and extent of locking under the north and south ends depend critically on assumptions regarding continuity and creep behavior of the fault at its ends. For the northern onshore part of the fault, our models contain 1.4-1.7 times more stored moment than the model of Bu??rgmann et al. [2000]; 45-57% of this stored moment resides in creeping areas. It is important for seismic hazard estimation to know how much of this moment is released coseismically or as aseismic afterslip.

Developing disaster management modules: a collaborative approach.

PubMed

Douglas, Valerie

Disasters, whether natural or human induced, can strike when least expected. The events of 9/11 in the US, the 7/7 bombings in the UK, and the anthrax incident in the US on 10th October 2001 indicate that there is a need to have a nursing workforce who is able to respond effectively to mass casualty events and incidents involving chemical, biological, radiological and nuclear substances. Multi-agency collaboration is one of the fundamental principles of disaster preparedness and response. It was therefore necessary to take a similar multi-agency collaborative approach to develop modules on the management of mass casualty events and incidents involving hazardous substances. The modules are offered to registered nurses and registered paramedics. They can be taken independently or as part of a BSc in nursing or health pathway, on a part-time basis. Since the commencement of the modules in September 2004, registered paramedics and registered nurses who work in a wide range of specialties have accessed them.

Elastic rebound following the Kocaeli earthquake, Turkey, recorded using synthetic aperture radar interferometry

USGS Publications Warehouse

Mayer, Larry; Lu, Zhong

2001-01-01

A basic model incorporating satellite synthetic aperture radar (SAR) interferometry of the fault rupture zone that formed during the Kocaeli earthquake of August 17, 1999, documents the elastic rebound that resulted from the concomitant elastic strain release along the North Anatolian fault. For pure strike-slip faults, the elastic rebound function derived from SAR interferometry is directly invertible from the distribution of elastic strain on the fault at criticality, just before the critical shear stress was exceeded and the fault ruptured. The Kocaeli earthquake, which was accompanied by as much as ∼5 m of surface displacement, distributed strain ∼110 km around the fault prior to faulting, although most of it was concentrated in a narrower and asymmetric 10-km-wide zone on either side of the fault. The use of SAR interferometry to document the distribution of elastic strain at the critical condition for faulting is clearly a valuable tool, both for scientific investigation and for the effective management of earthquake hazard.

Crustal strain partitioning and the associated earthquake hazard in the eastern Sunda-Banda Arc

NASA Astrophysics Data System (ADS)

Koulali, A.; Susilo, S.; McClusky, S.; Meilano, I.; Cummins, P.; Tregoning, P.; Lister, G.; Efendi, J.; Syafi'i, M. A.

2016-03-01

We use Global Positioning System (GPS) measurements of surface deformation to show that the convergence between the Australian Plate and Sunda Block in eastern Indonesia is partitioned between the megathrust and a continuous zone of back-arc thrusting extending 2000 km from east Java to north of Timor. Although deformation in this back-arc region has been reported previously, its extent and the mechanism of convergence partitioning have hitherto been conjectural. GPS observations establish that partitioning occurs via a combination of anticlockwise rotation of an arc segment called the Sumba Block, and left-lateral movement along a major NE-SW strike-slip fault west of Timor. We also identify a westward extension of the back-arc thrust for 300 km onshore into East Java, accommodating slip of ˜6 mm/yr. These results highlight a major new seismic threat for East Java and draw attention to the pronounced seismic and tsunami threat to Bali, Lombok, Nusa Tenggara, and other coasts along the Flores Sea.

Thyroid storm. A review of cases at University of California, San Francisco.

PubMed

Roizen, M; Becker, C E

1971-10-01

Retrospective study of the diagnosis and management of the 8 cases of thyroid storm in a series of 400 hyperthyroid patients led to conclusion that thyroid storm is a clinical diagnosis based on a life-endangering illness in a hyperthyroid patient whose hyperthyroidism has been severely exacerbated by a serious precipitating illness, and that storm is manifest by the symptoms of hyperpyrexia, tachycardia and striking alterations in consciousness. No laboratory tests were diagnostic of storm, and the underlying precipitating cause of thyroid storm was the major determinant of survival. Vigorous therapy must include blocking synthesis of thyroid hormones with antithyroid drugs, blocking release of preformed hormone with iodine, meticulous attention to hydration and supportive therapy, as well as correction of precipitating cause of storm. The blocking of the sympathetic nervous system with reserpine or guanethidine or with alpha and beta blocking drugs may be exceedingly hazardous and requires skillful management and constant monitoring in a critically ill patient.

Workplace violence prevention policies in home health and hospice care agencies.

PubMed

Gross, Nathan; Peek-Asa, Corinne; Nocera, Maryalice; Casteel, Carri

2013-01-31

Workplace violence in the home health industry is a growing concern, but little is known about the content of existing workplace violence prevention programs. The authors present the methods for this study that examined workplace violence prevention programs in a sample of 40 California home health and hospice agencies. Data was collected through surveys that were completed by the branch managers of participating facilities. Programs were scored in six different areas, including general workplace violence prevention components; management commitment and employee involvement; worksite analysis; hazard prevention and control; safety and health training; and recordkeeping and program evaluation. The results and discussion sections consider these six areas and the important gaps that were found in existing programs. For example, although most agencies offered workplace violence training, not every worker performing patient care was required to receive the training. Similarly, not all programs were written or reviewed and updated regularly. Few program differences were observed between agency characteristics, but nonetheless several striking gaps were found.

The Guanacaste Volcanic Arc Sliver of Northwestern Costa Rica.

PubMed

Montero, Walter; Lewis, Jonathan C; Araya, Maria Cristina

2017-05-11

Recent studies have shown that the Nicoya Peninsula of northwestern Costa Rica is moving northwestward ~11 mm a -1 as part of a tectonic sliver. Toward the northwest in El Salvador the northern sliver boundary is marked by a dextral strike-slip fault system active since Late Pleistocene time. To the southeast there is no consensus on what constitutes the northern boundary of the sliver, although a system of active crustal faults has been described in central Costa Rica. Here we propose that the Haciendas-Chiripa fault system serves as the northeastern boundary for the sliver and that the sliver includes most of the Guanacaste volcanic arc, herein the Guanacaste Volcanic Arc Sliver. In this paper we provide constraints on the geometry and kinematics of the boundary of the Guanacaste Volcanic Arc Sliver that are timely and essential to any models aimed at resolving the driving mechanism for sliver motion. Our results are also critical for assessing geological hazards in northwestern Costa Rica.

Gas and seismicity within the Istanbul seismic gap.

PubMed

Géli, L; Henry, P; Grall, C; Tary, J-B; Lomax, A; Batsi, E; Riboulot, V; Cros, E; Gürbüz, C; Işık, S E; Sengör, A M C; Le Pichon, X; Ruffine, L; Dupré, S; Thomas, Y; Kalafat, D; Bayrakci, G; Coutellier, Q; Regnier, T; Westbrook, G; Saritas, H; Çifçi, G; Çağatay, M N; Özeren, M S; Görür, N; Tryon, M; Bohnhoff, M; Gasperini, L; Klingelhoefer, F; Scalabrin, C; Augustin, J-M; Embriaco, D; Marinaro, G; Frugoni, F; Monna, S; Etiope, G; Favali, P; Bécel, A

2018-05-01

Understanding micro-seismicity is a critical question for earthquake hazard assessment. Since the devastating earthquakes of Izmit and Duzce in 1999, the seismicity along the submerged section of North Anatolian Fault within the Sea of Marmara (comprising the "Istanbul seismic gap") has been extensively studied in order to infer its mechanical behaviour (creeping vs locked). So far, the seismicity has been interpreted only in terms of being tectonic-driven, although the Main Marmara Fault (MMF) is known to strike across multiple hydrocarbon gas sources. Here, we show that a large number of the aftershocks that followed the M 5.1 earthquake of July, 25 th 2011 in the western Sea of Marmara, occurred within a zone of gas overpressuring in the 1.5-5 km depth range, from where pressurized gas is expected to migrate along the MMF, up to the surface sediment layers. Hence, gas-related processes should also be considered for a complete interpretation of the micro-seismicity (~M < 3) within the Istanbul offshore domain.

Risk factors for cutaneous myiasis (blowfly strike) in pet rabbits in Great Britain based on text-mining veterinary electronic health records.

PubMed

Turner, Rachel; Arsevska, Elena; Brant, Beth; Singleton, David A; Newman, Jenny; Noble, Pj-M; Jones, Philip H; Radford, Alan D

2018-05-01

Blowfly strike is a devastating and often rapidly fatal disease in rabbits. In Great Britain (GB), Lucilia sericata is the primary causative species. Despite its severity, there has been minimal investigatory work into the disease in rabbits. Here we used text mining to screen electronic health records (EHRs) from a large sentinel network of 389 veterinary practices in GB between March 2014 and April 2017 for confirmed cases of blowfly strike in rabbits. Blowfly strike was identified in 243 of 42,226 rabbit consultations (0.6%), affecting 205 individual rabbits. The anatomical site of recorded blowfly strike lesions was overwhelmingly the perineal area (n = 109, 52.4%). Less commonly lesions were observed affecting other areas of the body (n = 9, 4.3%) and head (n = 8, 3.8%); in 83 consultations (39.9%), the affected area was not specified. Of the rabbits presenting with blowfly strike, 44.7% were recorded as being euthanized or died. A case control study was used to identify risk factors for blowfly strike in this population. Whilst sex and neuter status in isolation were not significantly associated with blowfly strike, entire female rabbits showed a 3.3 times greater odds of being a case than neutered female rabbits. Rabbits five years of age and over were more than 3.8 times likely to present for blowfly strike. For every 1 °C rise in environmental temperature between 4.67 °C and 17.68 °C, there was a 33% increase risk of blowfly strike, with cases peaking in July or August. Overall blowfly strike cases started earlier and peaked higher in the south of Great Britain. The most northerly latitude studied was at lower risk of blowfly strike than the most southerly (OR = 0.50, p < 0.001). There appeared to be no significant relationship between blowfly strike in rabbits and either the sheep density or rural and urban land coverage types. The results presented here can be used for targeted health messaging to reduce the impact of this deadly disease for rabbits. We propose that real-time temporal and spatial surveillance of the rabbit disease may also help inform sheep control, where the seasonal profile is very similar, and where routine surveillance data is also not available. Our results highlight the value of sentinel databases based on EHRs for research and surveillance. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Glacial hazards: communicating the science and managing the risk

NASA Astrophysics Data System (ADS)

Reynolds, J. M.

2009-04-01

The recession of glaciers worldwide has received huge media coverage over the last few years in association with the issue of climate change. Young people at schools and colleges are increasingly aware of the environmental pressures due to ‘global warming'. Yet simultaneously, there appears to be an increasing move away from studying science both at pre-university and undergraduate levels. One of the oft cited reasons is that students cannot see the application of the subjects being taught them. Glacial hazards are one of the most obvious adverse effects of climate change, with many, often poor, communities in remote mountain areas being the most affected by frequently devastating Glacial Lake Outburst Floods (GLOFs). When students are exposed to examples of these hazards and the science behind them, many become enthused by the subject and want to study it further. There has been a huge increase in the number of students selecting projects on glacial hazards as well as a large increase in the number of institutions offering to teach modules on this subject. In an effort to provide a basic visualisation, Peter Kennett has taken the principle of GLOFs and developed a cheap but highly visual demonstration of the potentially devastating effect of melting ice within a moraine leading to subsidence and subsequent dam failure. This is available on www.earthlearningidea.com as ‘Dam burst danger - modelling the collapse of a natural dam in the mountains - and the disaster that might follow'. Furthermore, the methods by which glacial hazards are assessed provide excellent applications of geophysics, geology, geography (physical and Human), engineering, mathematics, and glaciology. By exploring the potential vulnerability of communities downstream, the applications can be extended to include sociology, economics, geopolitics and even psychology. Glacial hazards have been the subject of presentations to the Earth Science Teachers Association (ESTA) in the UK to demonstrate these scientific applications. Communicating the science to students and trying to excite them to the fun of applying these scientific disciplines in the field are important as part of science outreach. It is also important to communicate the science to those in government (local and national) within those countries affected by such hazards and to international funding agencies. There are two issues here: (a) using the media to a positive effect without alarming vulnerable and sensitive communities, and (b) providing the appropriate authorities with the necessary technical information about the hazards, their potential effects if catastrophe strikes, and how to manage the risk in an effective and timely fashion. For (a) where this is not handled correctly, the media are still ever too keen to headline potential catastrophes and unwittingly cause alarm among local communities. The so-called Palcacocha fiasco in the Cordillera Blanca, Peru, in April 2003 and the Imja Tsho media flurry of May 2008 in Nepal are but two recent examples. For (b) there needs to be a programme of interaction through workshops between the scientific community and key stakeholders in affected countries. Where these have been undertaken, such as in Bhutan, Nepal and Peru, the outcomes have been extremely productive and beneficial. However, much remains to be done in ensuring that authorities and funding agencies, for example, are aware of existing international guidelines on the assessment of glacial hazards that use objective methodologies, such as those funded by the British Government and published in 2003 (see www.geologyuk.com/mountain_ hazards_group/dfid.htm from which the guidelines can be downloaded in PDF format). Similar workshops, for example, are also being developed separately in Austria by the Glacier and Permafrost Hazard (GAPHAZ) Working Group and in Bhutan by the UNDP.

Evidence of a double peak in muscle activation to enhance strike speed and force: an example with elite mixed martial arts fighters.

PubMed

McGill, Stuart M; Chaimberg, Jon D; Frost, David M; Fenwick, Chad M J

2010-02-01

The main issue addressed here is the paradox of muscle contraction to optimize speed and strike force. When muscle contracts, it increases in both force and stiffness. Force creates faster movement, but the corresponding stiffness slows the change of muscle shape and joint velocity. The purpose of this study was to investigate how this speed strength is accomplished. Five elite mixed martial arts athletes were recruited given that they must create high strike force very quickly. Muscle activation using electromyography and 3-dimensional spine motion was measured. A variety of strikes were performed. Many of the strikes intend to create fast motion and finish with a very large striking force, demonstrating a "double peak" of muscle activity. An initial peak was timed with the initiation of motion presumably to enhance stiffness and stability through the body before motion. This appeared to create an inertial mass in the large "core" for limb muscles to "pry" against to initiate limb motion. Then, some muscles underwent a relaxation phase as speed of limb motion increased. A second peak was observed upon contact with the opponent (heavy bag). It was postulated that this would increase stiffness through the body linkage, resulting in a higher effective mass behind the strike and likely a higher strike force. Observation of the contract-relax-contract pulsing cycle during forceful and quick strikes suggests that it may be fruitful to consider pulse training that involves not only the rate of muscle contraction but also the rate of muscle relaxation.

Predicting timing of foot strike during running, independent of striking technique, using principal component analysis of joint angles.

PubMed

Osis, Sean T; Hettinga, Blayne A; Leitch, Jessica; Ferber, Reed

2014-08-22

As 3-dimensional (3D) motion-capture for clinical gait analysis continues to evolve, new methods must be developed to improve the detection of gait cycle events based on kinematic data. Recently, the application of principal component analysis (PCA) to gait data has shown promise in detecting important biomechanical features. Therefore, the purpose of this study was to define a new foot strike detection method for a continuum of striking techniques, by applying PCA to joint angle waveforms. In accordance with Newtonian mechanics, it was hypothesized that transient features in the sagittal-plane accelerations of the lower extremity would be linked with the impulsive application of force to the foot at foot strike. Kinematic and kinetic data from treadmill running were selected for 154 subjects, from a database of gait biomechanics. Ankle, knee and hip sagittal plane angular acceleration kinematic curves were chained together to form a row input to a PCA matrix. A linear polynomial was calculated based on PCA scores, and a 10-fold cross-validation was performed to evaluate prediction accuracy against gold-standard foot strike as determined by a 10 N rise in the vertical ground reaction force. Results show 89-94% of all predicted foot strikes were within 4 frames (20 ms) of the gold standard with the largest error being 28 ms. It is concluded that this new foot strike detection is an improvement on existing methods and can be applied regardless of whether the runner exhibits a rearfoot, midfoot, or forefoot strike pattern. Copyright © 2014 Elsevier Ltd. All rights reserved.