Up-dip partitioning of displacement components on the oblique-slip Clarence Fault, New Zealand

NASA Astrophysics Data System (ADS)

Nicol, Andrew; Van Dissen, Russell

2002-09-01

Active strike-slip faults in New Zealand occur within an obliquely-convergent plate boundary zone. Although the traces of these faults commonly delineate the base of mountain ranges, they do not always accommodate significant shortening at the free surface. Along the active trace of Clarence Fault in northeastern South Island, New Zealand, displaced landforms and slickenside striations indicate predominantly horizontal displacements at the ground surface, and a right-lateral slip rate of ca. 3.5-5 mm/year during the Holocene. The Inland Kaikoura mountain range occupies the hanging wall of the fault and rises steeply from the active trace to altitudes of ca. 3 km. The geomorphology of the range indicates active uplift and mountain building, which is interpreted to result, in part, from a vertical component of fault slip at depth. These data are consistent with the fault accommodating oblique-slip at depth aligned parallel to the plate-motion vector and compatible with regional geodetic data and earthquake focal-mechanisms. Oblique-slip on the Clarence Fault at depth is partitioned at the free surface into: (1) right-lateral displacement on the fault, and (2) hanging wall uplift produced by distributed displacement on small-scale faults parallel to the main fault. Decoupling of slip components reflects an up-dip transfer of fault throw to an off-fault zone of distributed uplift. Such zones are common in the hanging walls of thrusts and reverse faults, and support the idea that the dip of the oblique-slip Clarence Fault steepens towards the free surface.

Circumferential graben and the structural evolution of Alba Mons, Mars

NASA Astrophysics Data System (ADS)

Öhman, Teemu; McGovern, Patrick J.

2014-05-01

Alba Mons is a unique, very extensive but shallow volcanotectonic construct in northern Tharsis, Mars. Numerous models have been presented to explain the formation of Alba Mons and its most characteristic feature, a wristwatch-like pattern of radial and circumferential graben. We used a wide selection of topographic datasets to characterize the fault throw variation on nine topographic transects across the circumferential graben in order to provide observational constraints for the different formation models, and to gain further insight into the evolution of Alba Mons. In most of the transects, summed throws from outwards-facing (away from the center of the volcano) faults are larger than from the inwards-facing (towards the center) ones. Only the very gently sloping western transects show the opposite, emphasizing the east-west-asymmetry of Alba Mons. 10-40% of the observed topographic relief of Alba Mons along the nine transects can be accounted for by this throw difference between the inwards- and outwards-facing faults. These results are consistent with predictions of models suggesting an uplift mechanism to explain the formation of the circumferential graben, but not with models invoking central subsidence. Horizontal extensional strain along the transects varies between 0.5% and 2%, consistent with strain predictions of the late-stage sill complex inflation model of McGovern et al. (McGovern, P.J., Solomon, S.C., Head J.W. III, Smith, D.E., Zuber M.T., Neumann, G.A. [2001]. J. Geophys. Res. 106(E10), 23769-23809).

Fault and joint measurements in Austin Chalk, Superconducting Super Collider Site, Texas

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

Nance, H.S.; Laubach, S.E.; Dutton, A.R.

1994-12-31

Structure maps of 9.4 mi of nearly continuous tunnel excavations and more than 10 mi of other exposures and excavations in Austin Chalk at the Superconducting Super Collider (SSC) site in Ellis County, Texas, record normal-fault and joint populations in the subsurface within the northern segment of the Balcones Fault Zone with unmatched resolution for such a long traverse. Small faults (<10 ft throw) occur in clusters or swarms that have as many as 24 faults. Fault swarms are as much as 2,000 ft wide, and spacing between swarms ranges from 800 to 2,000 ft, averaging about 1,000 ft. Predominantlymore » northeast-trending joints are in swarms spaced 500 to more than 21,000 ft apart.« less

Ramadan oil field

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

El Shazly, S.; Garossino, G.A.

1991-03-01

Ramadan oil field, located in the central Gulf of Suez, is one of the giant oil fields of Egypt. It is named for the Islamic month of Ramadan during which it was discovered through the drilling of the well GS303-1 in September of 1974. Production comes primarily from within the massive sandstone reservoir of the Nubia 'C' Formation which covers some 2,850 ac with an oil column in excess of 1,000 ft. Secondary production occurs within both the Nubia 'A' Formation and Nezzazat Group. The northeasterly dipping Nubia 'C' reservoir is bounded to the west by two northwest-southeasterly oriented faultmore » systems which are of similar throw but have significantly different ages. Northern Ramadan field is bounded by a late Miocene age fault, which transfers 75% of its throw through a series of southwest-northeasterly trending faults to a preexisting Oligo-Miocene age fault to the south. The latter bounds the southern half of the field and is typified by a heavily eroded scarp present at the pre-Miocene unconformity. The recent discovery of this scarp has allowed the westward repositioning of the updip limit of the Nubia 'C' reservoir resulting in a significant increase in recoverable reserves.« less

Active transpressional tectonics in the Andean forearc of southern Peru quantified by 10Be surface exposure dating of an active fault scarp

NASA Astrophysics Data System (ADS)

Benavente, Carlos; Zerathe, Swann; Audin, Laurence; Hall, Sarah R.; Robert, Xavier; Delgado, Fabrizio; Carcaillet, Julien; Team, Aster

2017-09-01

Our understanding of the style and rate of Quaternary tectonic deformation in the forearc of the Central Andes is hampered by a lack of field observations and constraints on neotectonic structures. Here we present a detailed analysis of the Purgatorio fault, a recently recognized active fault located in the forearc of southern Peru. Based on field and remote sensing analysis (Pléiades DEM), we define the Purgatorio fault as a subvertical structure trending NW-SE to W-E along its 60 km length, connecting, on its eastern end, to the crustal Incapuquio Fault System. The Purgatorio fault accommodates right-lateral transpressional deformation, as shown by the numerous lateral and vertical plurimetric offsets recorded along strike. In particular, scarp with a 5 m cumulative throw is preserved and displays cobbles that are cut and covered by slickensides. Cosmogenic radionuclide exposure dating (10Be) of quartzite cobbles along the vertical fault scarp yields young exposure ages that can be bracketed between 0 to 6 ka, depending on the inheritance model that is applied. Our preferred scenario, which takes in account our geomorphic observations, implies at least two distinct rupture events, each associated with 3 and 2 m of vertical offset. These two events plausibly occurred during the last thousand years. Nevertheless, an interpretation invoking more tectonic events along the fault cannot be ruled out. This work affirms crustal deformation along active faults in the Andean forearc of southern Peru during the last thousand years.

The temporal and spatial distribution of upper crustal faulting and magmatism in the south Lake Turkana rift, East Africa

NASA Astrophysics Data System (ADS)

Muirhead, J.; Scholz, C. A.

2017-12-01

During continental breakup extension is accommodated in the upper crust largely through dike intrusion and normal faulting. The Eastern branch of the East African Rift arguably represents the premier example of active continental breakup in the presence magma. Constraining how faulting is distributed in both time and space in these regions is challenging, yet can elucidate how extensional strain localizes within basins as rifting progresses to sea-floor spreading. Studies of active rifts, such as the Turkana Rift, reveal important links between faulting and active magmatic processes. We utilized over 1100 km of high-resolution Compressed High Intensity Radar Pulse (CHIRP) 2D seismic reflection data, integrated with a suite of radiocarbon-dated sediment cores (3 in total), to constrain a 17,000 year history of fault activity in south Lake Turkana. Here, a set of N-S-striking intra-rift faults exhibit time-averaged slip-rates as high as 1.6 mm/yr, with the highest slip-rates occurring along faults within 3 km of the rift axis. Results show that strain has localized into a zone of intra-rift faults along the rift axis, forming an approximately 20 km-wide graben in central parts of the basin. Subsurface structural mapping and fault throw profile analyses reveal increasing basin subsidence and fault-related strain as this faulted graben approaches a volcanic island in the center of the basin (South Island). The long-axis of this island trends north-south, and it contains a number of elongate cones that support recent emplacement of N-S-striking dike intrusions, which parallel recently active intra-rift faults. Overall, these observations suggest strain localization into intra-rift faults in the rift center is likely a product of both volcanic loading and the mechanical and thermal effects of diking along the rift axis. These results support the establishment of magmatic segmentation in southern Lake Turkana, and highlight the importance of magmatism for focusing upper crustal strain as rifts evolve to sea-floor spreading.

Using T-Z plots as a graphical method to infer lithological variations from growth strata

NASA Astrophysics Data System (ADS)

Castelltort, Sébastien; Pochat, Stéphane; Van Den Driessche, Jean

2004-08-01

The 'T-Z plot' method consists of plotting the throw of sedimentary horizons across a growth fault versus their depth in the hanging wall. This method has been initially developed for the analysis of growth fault kinematics from seismic data. A brief analytical examination of such plots shows that they can also provide valuable information about the evolution of fault topography. When growth is a continuous process, stages of topography creation (fault scarp) and filling (of the space available in the hanging-wall) are related to non-dynamic (draping, mud-prone pelagic settling) and dynamic (sand-prone, dynamically deposited) sedimentation, respectively. In this case, the T-Z plot analysis becomes a powerful tool to predict major lithological variations on seismic profiles in faulted settings.

Sandstone-filled normal faults: A case study from central California

NASA Astrophysics Data System (ADS)

Palladino, Giuseppe; Alsop, G. Ian; Grippa, Antonio; Zvirtes, Gustavo; Phillip, Ruy Paulo; Hurst, Andrew

2018-05-01

Despite the potential of sandstone-filled normal faults to significantly influence fluid transmissivity within reservoirs and the shallow crust, they have to date been largely overlooked. Fluidized sand, forcefully intruded along normal fault zones, markedly enhances the transmissivity of faults and, in general, the connectivity between otherwise unconnected reservoirs. Here, we provide a detailed outcrop description and interpretation of sandstone-filled normal faults from different stratigraphic units in central California. Such faults commonly show limited fault throw, cm to dm wide apertures, poorly-developed fault zones and full or partial sand infill. Based on these features and inferences regarding their origin, we propose a general classification that defines two main types of sandstone-filled normal faults. Type 1 form as a consequence of the hydraulic failure of the host strata above a poorly-consolidated sandstone following a significant, rapid increase of pore fluid over-pressure. Type 2 sandstone-filled normal faults form as a result of regional tectonic deformation. These structures may play a significant role in the connectivity of siliciclastic reservoirs, and may therefore be crucial not just for investigation of basin evolution but also in hydrocarbon exploration.

Paleoseismic study of the Kamishiro Fault on the northern segment of the Itoigawa-Shizuoka Tectonic Line, Japan

NASA Astrophysics Data System (ADS)

Lin, Aiming; Sano, Mikako; Wang, Maomao; Yan, Bing; Bian, Di; Fueta, Ryoji; Hosoya, Takashi

2017-07-01

The Mw 6.2 (Mj 6.8) Nagano (Japan) earthquake of 22 November 2014 produced a 9.3-km long surface rupture zone with a thrust-dominated displacement of up to 1.5 m, which duplicated the pre-existing Kamishiro Fault along the Itoigawa-Shizuoka Tectonic Line (ISTL), the plate-boundary between the Eurasian and North American plates, northern Nagano Prefecture, central Japan. To characterize the activity of the seismogenic fault zone, we conducted a paleoseismic study of the Kamishiro Fault. Field investigations and trench excavations revealed that seven morphogenic paleohistorical earthquakes (E2-E8) prior to the 2014 Mw 6.2 Nagano earthquake (E1) have occurred on the Kamishiro Fault during the last ca. 6000 years. Three of these events (E2-E4) are well constrained and correspond to historical earthquakes occurring in the last ca. 1200 years. This suggests an average recurrence interval of ca. 300-400 years on the seismogenic fault of the 2014 Kamishiro earthquake in the past 1200 years. The most recent event prior to the 2014 earthquakes (E1) is E2 and the penultimate and antepenultimate faulting events are E3 and E4, respectively. The penultimate faulting event (E3) occurred during the period of AD 1800-1400 and is associated with the 1791 Mw 6.8 earthquake. The antepenultimate faulting event (E4) is inferred to have occurred during the period of ca. AD 1000-700, likely corresponding to the AD 841 Mw 6.5 earthquake. The oldest faulting event (E8) in the study area is thought to have occurred during the period of ca. 5600-6000 years. The throw rate during the early Holocene is estimated to be 1.2-3.3 mm/a (average, 2.2 mm/a) with an average amount of characteristic offset of 0.7-1.1 m produced by individual event. When compared with active intraplate faults on Honshu Island, Japan, these slip rates and recurrence interval estimated for morphogenic earthquakes on the Kamishiro Fault along the ISTL appear high and short, respectively. This indicates that present activity on this fault is closely related to seismic faulting along the plate boundary between the Eurasian and North American plates.

Paleoseismic study of the Kamishiro Fault on the northern segment of the Itoigawa-Shizuoka Tectonic Line, Japan.

PubMed

Lin, Aiming; Sano, Mikako; Wang, Maomao; Yan, Bing; Bian, Di; Fueta, Ryoji; Hosoya, Takashi

2017-01-01

The M w 6.2 (Mj 6.8) Nagano (Japan) earthquake of 22 November 2014 produced a 9.3-km long surface rupture zone with a thrust-dominated displacement of up to 1.5 m, which duplicated the pre-existing Kamishiro Fault along the Itoigawa-Shizuoka Tectonic Line (ISTL), the plate-boundary between the Eurasian and North American plates, northern Nagano Prefecture, central Japan. To characterize the activity of the seismogenic fault zone, we conducted a paleoseismic study of the Kamishiro Fault. Field investigations and trench excavations revealed that seven morphogenic paleohistorical earthquakes (E2-E8) prior to the 2014 M w 6.2 Nagano earthquake (E1) have occurred on the Kamishiro Fault during the last ca. 6000 years. Three of these events (E2-E4) are well constrained and correspond to historical earthquakes occurring in the last ca. 1200 years. This suggests an average recurrence interval of ca. 300-400 years on the seismogenic fault of the 2014 Kamishiro earthquake in the past 1200 years. The most recent event prior to the 2014 earthquakes (E1) is E2 and the penultimate and antepenultimate faulting events are E3 and E4, respectively. The penultimate faulting event (E3) occurred during the period of AD 1800-1400 and is associated with the 1791 M w 6.8 earthquake. The antepenultimate faulting event (E4) is inferred to have occurred during the period of ca. AD 1000-700, likely corresponding to the AD 841 M w 6.5 earthquake. The oldest faulting event (E8) in the study area is thought to have occurred during the period of ca. 5600-6000 years. The throw rate during the early Holocene is estimated to be 1.2-3.3 mm/a (average, 2.2 mm/a) with an average amount of characteristic offset of 0.7-1.1 m produced by individual event. When compared with active intraplate faults on Honshu Island, Japan, these slip rates and recurrence interval estimated for morphogenic earthquakes on the Kamishiro Fault along the ISTL appear high and short, respectively. This indicates that present activity on this fault is closely related to seismic faulting along the plate boundary between the Eurasian and North American plates.

Seismicity and Tectonics of the West Kaibab Fault Zone, AZ

NASA Astrophysics Data System (ADS)

Wilgus, J. T.; Brumbaugh, D. S.

2014-12-01

The West Kaibab Fault Zone (WKFZ) is the westernmost bounding structure of the Kaibab Plateau of northern Arizona. The WKFZ is a branching complex of high angle, normal faults downthrown to the west. There are three main faults within the WKFZ, the Big Springs fault with a maximum of 165 m offset, the Muav fault with 350 m of displacement, and the North Road fault having a maximum throw of approximately 90 m. Mapping of geologically recent surface deposits at or crossing the fault contacts indicates that the faults are likely Quaternary with the most recent offsets occurring <1.6 Ma. Slip rates are estimated to be less than 0.2 mm/yr. No historic fault slip has been documented. The WKFZ is one of the most seismically active areas in Arizona and lies within the Northern Arizona Seismic Belt (NASB), which stretches across northern Arizona trending NW-SE. The data set for this study includes 156 well documented events with the largest being a M5.75 in 1959 and including a swarm of seven earthquakes in 2012. The seismic data set (1934-2014) reveals that seismic activity clusters in two regions within the study area, the Fredonia cluster located in the NW corner of the study area and the Kaibab cluster located in the south central portion of the study area. The fault plane solutions to date indicate NE-SW to EW extension is occurring in the study area. Source relationships between earthquakes and faults within the WKFZ have not previously been studied in detail. The goal of this study is to use the seismic data set, the available data on faults, and the regional physiography to search for source relationships for the seismicity. Analysis includes source parameters of the earthquake data (location, depth, and fault plane solutions), and comparison of this output to the known faults and areal physiographic framework to indicate any active faults of the WKFZ, or suggested active unmapped faults. This research contributes to a better understanding of the present nature of the WKFZ and the NASB as well.

Elasto-plastic deformation and plate weakening due to normal faulting in the subducting plate along the Mariana Trench

NASA Astrophysics Data System (ADS)

Zhou, Zhiyuan; Lin, Jian

2018-06-01

We investigated variations in the elasto-plastic deformation of the subducting plate along the Mariana Trench through an analysis of flexural bending and normal fault characteristics together with geodynamic modeling. Most normal faults were initiated at the outer-rise region and grew toward the trench axis with strikes mostly subparallel to the local trench axis. The average trench relief and maximum fault throws were measured to be significantly greater in the southern region (5 km and 320 m, respectively) than the northern and central regions (2 km and 200 m). The subducting plate was modeled as an elasto-plastic slab subjected to tectonic loading at the trench axis. The calculated strain rates and velocities revealed an array of normal fault-like shear zones in the upper plate, resulting in significant faulting-induced reduction in the deviatoric stresses. We then inverted for solutions that best fit the observed flexural bending and normal faulting characteristics, revealing normal fault penetration to depths of 21, 20, and 32 km beneath the seafloor for the northern, central, and southern regions, respectively, which is consistent with the observed depths of the relocated normal faulting earthquakes in the central Mariana Trench. The calculated deeper normal faults of the southern region might lead to about twice as much water being carried into the mantle per unit trench length than the northern and central regions. We further calculated that normal faulting has reduced the effective elastic plate thickness Te by up to 52% locally in the southern region and 33% in both the northern and central regions. The best-fitting solutions revealed a greater apparent angle of the pulling force in the southern region (51-64°) than in the northern (22-35°) and central (20-34°) regions, which correlates with a general southward increase in the seismically-determined dip angle of the subducting slab along the Mariana Trench.

Multi-phase inversion tectonics related to the Hendijan-Nowrooz-Khafji Fault activity, Zagros Mountains, SW Iran

NASA Astrophysics Data System (ADS)

Kazem Shiroodi, Sadjad; Ghafoori, Mohammad; Faghih, Ali; Ghanadian, Mostafa; Lashkaripour, Gholamreza; Hafezi Moghadas, Naser

2015-11-01

Distinctive characteristics of inverted structures make them important criteria for the identification of certain structural styles of folded belts. The interpretation of 3D seismic reflection and well data sheds new light on the structural evolution and age of inverted structures associated to the Hendijan-Nowrooz-Khafji Fault within the Persian Gulf Basin and northeastern margin of Afro-Arabian plate. Analysis of thickness variations of growth strata using "T-Z plot" (thickness versus throw plot) method revealed the kinematics of the fault. Obtained results show that the fault has experienced a multi-phase evolutionary history over six different extension and compression deformation events (i.e. positive and negative inversion) between 252.2 and 11.62 Ma. This cyclic activity of the growth fault was resulted from alteration of sedimentary processes during continuous fault slip. The structural development of the study area both during positive and negative inversion geometry styles was ultimately controlled by the relative motion between the Afro-Arabian and Central-Iranian plates.

An Unexpected Effect: Restitution Maintains Object Throwing.

ERIC Educational Resources Information Center

Jensen, Mary

1988-01-01

This study examined effects of restitution on object throwing behavior of an adolescent male with severe mental retardation. Restitution was shown to maintain throwing behavior. When the subject was not forced to pick up what he threw (no restitution), throwing dropped to zero and was maintained at a very low rate. (Author/PB)

Fault-related clay authigenesis along the Moab Fault: Implications for calculations of fault rock composition and mechanical and hydrologic fault zone properties

USGS Publications Warehouse

Solum, J.G.; Davatzes, N.C.; Lockner, D.A.

2010-01-01

The presence of clays in fault rocks influences both the mechanical and hydrologic properties of clay-bearing faults, and therefore it is critical to understand the origin of clays in fault rocks and their distributions is of great importance for defining fundamental properties of faults in the shallow crust. Field mapping shows that layers of clay gouge and shale smear are common along the Moab Fault, from exposures with throws ranging from 10 to ???1000 m. Elemental analyses of four locations along the Moab Fault show that fault rocks are enriched in clays at R191 and Bartlett Wash, but that this clay enrichment occurred at different times and was associated with different fluids. Fault rocks at Corral and Courthouse Canyons show little difference in elemental composition from adjacent protolith, suggesting that formation of fault rocks at those locations is governed by mechanical processes. Friction tests show that these authigenic clays result in fault zone weakening, and potentially influence the style of failure along the fault (seismogenic vs. aseismic) and potentially influence the amount of fluid loss associated with coseismic dilation. Scanning electron microscopy shows that authigenesis promotes that continuity of slip surfaces, thereby enhancing seal capacity. The occurrence of the authigenesis, and its influence on the sealing properties of faults, highlights the importance of determining the processes that control this phenomenon. ?? 2010 Elsevier Ltd.

Distribution and nature of fault architecture in a layered sandstone and shale sequence: An example from the Moab fault, Utah

USGS Publications Warehouse

Davatzes, N.C.; Aydin, A.

2005-01-01

We examined the distribution of fault rock and damage zone structures in sandstone and shale along the Moab fault, a basin-scale normal fault with nearly 1 km (0.62 mi) of throw, in southeast Utah. We find that fault rock and damage zone structures vary along strike and dip. Variations are related to changes in fault geometry, faulted slip, lithology, and the mechanism of faulting. In sandstone, we differentiated two structural assemblages: (1) deformation bands, zones of deformation bands, and polished slip surfaces and (2) joints, sheared joints, and breccia. These structural assemblages result from the deformation band-based mechanism and the joint-based mechanism, respectively. Along the Moab fault, where both types of structures are present, joint-based deformation is always younger. Where shale is juxtaposed against the fault, a third faulting mechanism, smearing of shale by ductile deformation and associated shale fault rocks, occurs. Based on the knowledge of these three mechanisms, we projected the distribution of their structural products in three dimensions along idealized fault surfaces and evaluated the potential effect on fluid and hydrocarbon flow. We contend that these mechanisms could be used to facilitate predictions of fault and damage zone structures and their permeability from limited data sets. Copyright ?? 2005 by The American Association of Petroleum Geologists.

Associations Between Rate of Force Development Metrics and Throwing Velocity in Elite Team Handball Players: a Short Research Report

PubMed Central

Marques, Mário C.; Saavedra, Francisco J.; Abrantes, Catarina; Aidar, Felipe J.

2011-01-01

Performance assessment has become an invaluable component of monitoring participant’s development in distinct sports, yet limited and contradictory data are available in trained subjects. The purpose of this study was to examine the relationship between ball throwing velocity during a 3-step running throw in elite team handball players and selected measures of rate of force development like force, power, velocity, and bar displacement during a concentric only bench press exercise in elite male handball players. Fitteen elite senior male team handball players volunteered to participate. Each volunteer had power and bar velocity measured during a concentric only bench press test with 25, 35, and 45 kg as well as having one-repetition maximum strength determined. Ball throwing velocity was evaluated with a standard 3-step running throw using a radar gun. The results of this study indicated significant associations between ball velocity and time at maximum rate of force development (0, 66; p<0.05) and rate of force development at peak force (0,56; p<0.05) only with 25kg load. The current research indicated that ball velocity was only median associated with maximum rate of force development with light loads. A training regimen designed to improve ball-throwing velocity in elite male team handball players should emphasize bench press movement using light loads. PMID:23487363

Associations between rate of force development metrics and throwing velocity in elite team handball players: a short research report.

PubMed

Marques, Mário C; Saavedra, Francisco J; Abrantes, Catarina; Aidar, Felipe J

2011-09-01

Performance assessment has become an invaluable component of monitoring participant's development in distinct sports, yet limited and contradictory data are available in trained subjects. The purpose of this study was to examine the relationship between ball throwing velocity during a 3-step running throw in elite team handball players and selected measures of rate of force development like force, power, velocity, and bar displacement during a concentric only bench press exercise in elite male handball players. Fitteen elite senior male team handball players volunteered to participate. Each volunteer had power and bar velocity measured during a concentric only bench press test with 25, 35, and 45 kg as well as having one-repetition maximum strength determined. Ball throwing velocity was evaluated with a standard 3-step running throw using a radar gun. The results of this study indicated significant associations between ball velocity and time at maximum rate of force development (0, 66; p<0.05) and rate of force development at peak force (0,56; p<0.05) only with 25kg load. The current research indicated that ball velocity was only median associated with maximum rate of force development with light loads. A training regimen designed to improve ball-throwing velocity in elite male team handball players should emphasize bench press movement using light loads.

10Be erosion rates controlled by normal fault activity through incision and landslide occurrence

NASA Astrophysics Data System (ADS)

Roda-Boluda, Duna; D'Arcy, Mitch; Whittaker, Alex; Gheorghiu, Delia; Rodes, Angel

2017-04-01

Quantifying erosion rates, and how they compare to rock uplift rates, is fundamental for understanding the evolution of relief and the associated sediment fluxes. The competing effects of rock uplift and erosion are clearly captured by river incision and landsliding, but linking these four important landscape processes remains a major challenge. We address these questions using field data from southern Italy, and quantify the geomorphic response to tectonic forcing. We present 15 new 10Be catchment-averaged erosion rates, collected from catchments along five active normal faults with excellent slip rate constraints. We find that erosion rates are strongly controlled by fault slip rates and that this relationship is mediated by the degree of catchment incision and landslide activity. We find that 10Be samples from low-relief, unincised areas above knickpoints yield consistent erosion rates of ˜ 0.12 mm/yr, while samples collected below knickpoints have erosion rates of ˜ 0.2 - 1.0 mm/yr. This comparison allows us to quantify the impact that transient incisional response has on erosion rates. We demonstrate that in this area incision is associated with frequent, shallow landsliding, and we show that the volumes of landslides stored in the catchments are highly correlated with 10Be-derived sediment flux estimates, suggesting that landslides are likely to be a major contributor to erosional fluxes. Despite widespread landsliding, CRN samples from the studied catchments do provide reliable estimates of catchment-averaged erosion rates, as these are consistent with fault throw patterns and rates. We suggest that this is because landslides are frequent, small and shallow, and are stored on the hillslopes for up to ˜ 103 yrs, representing the integrated record of landsliding over several seismic cycles; and test this hypothesis using a numerical model of landsliding and CRN dynamics. Our results show that adequate CRN mixing can occur through runoff as landslides are stored on the hillslopes, as long as landslide recurrence intervals are short, which is supported by the erosion rate magnitudes and previous landslide studies in the area. This study contributes to our understanding of erosion and sediment supply in tectonically-active areas, and offers novel insights into the use of CRN to infer erosion rates in areas of intense landslide activity.

Fault rock texture and porosity type in Triassic dolostones

NASA Astrophysics Data System (ADS)

Agosta, Fabrizio; Grieco, Donato; Bardi, Alessandro; Prosser, Giacomo

2015-04-01

Preliminary results of an ongoing project aimed at deciphering the micromechanics and porosity evolution associated to brittle deformation of Triassic dolostones are presented. Samples collected from high-angle, oblique-slip, 10's to 100's m-throw normal faults crosscutting Mesozoic carbonates of the Neo Tethys (Campanian-Lucanian Platform) are investigated by mean of field geological mapping, optical microscopy, SEM and image analyses. The goal is to characterize in detail composition, texture and porosity of cataclastic rocks in order to assess the structural architecture of dolomitic fault cores. Moreover, the present study addresses the time-space control exerted by several micro-mechanisms such as intragranular extensional fracturing, chipping and shear fracturing, which took place during grain rolling and crushing within the evolving faults, on type, amount, dimensions and distribution of micropores present within the cataclastic fault cores. Study samples are representative of well-exposed dolomitic fault cores of oblique-slip normal faults trending either NW-SE or NE-SW. The high-angle normal faults crosscut the Mesozoic carbonates of the Campanian-Lucanian Platform, which overrode the Lagonegro succession by mean of low-angle thrust faults. Fault throws are measured by considering the displaced thrust faults as key markers after large scale field mapping (1:10,000 scale) of the study areas. In the field, hand samples were selected according to their distance from main slip surfaces and, in some case, along secondary slip surfaces. Microscopy analysis of about 100 oriented fault rock samples shows that, mostly, the study cataclastic rocks are made up of dolomite and sparse, minute survivor silicate grains deriving from the Lagonegro succession. In order to quantitatively assess the main textural classes, a great attention is paid to the grain-matrix ratio, grain sphericity, grain roundness, and grain sorting. By employing an automatic box-counting technique, the fractal dimension of representative samples is also computed. Results of such a work shows that five main textural types are present: 1) fractured and fragmented dolomites; 2) protocataclasites characterized by intense intragranular extensional fracturing; 3) cataclasites due to a chipping-dominated mechanism; 4) cataclasites and ultracataclasites with pronounced shear fracturing; 5) cemented fault rocks, which localize along the main slip surfaces. The first four textural types are therefore indicative to the fault rock maturity within individual cataclastic fault cores. A negative correlation among grain-matrix ratio and grain sphericity, roundness and sorting is computed, which implies that ultracataclasites are made up of more spherical and rounded smaller grains relative to cataclasites and protocataclasites. Each textural type shows distinct D0-values (box-counting dimension). As expected, a good correlation between the D0-value and fault rock maturity is computed. Ongoing analysis of selected images obtained from representative samples of the five textural classes will shed lights on the relative role played by the aforementioned micro-mechanisms on the porosity evolution within the cataclastic fault cores.

Corridors of crestal and radial faults linking salt diapirs in the Espírito Santo Basin, SE Brazil

NASA Astrophysics Data System (ADS)

Mattos, Nathalia H.; Alves, Tiago M.

2018-03-01

This work uses high-quality 3D seismic data to assess the geometry of fault families around salt diapirs in SE Brazil (Espírito Santo Basin). It aims at evaluating the timings of fault growth, and suggests the generation of corridors for fluid migration linking discrete salt diapirs. Three salt diapirs, one salt ridge, and five fault families were identified based on their geometry and relative locations. Displacement-length (D-x) plots, Throw-depth (T-z) data and structural maps indicate that faults consist of multiple segments that were reactivated by dip-linkage following a preferential NE-SW direction. This style of reactivation and linkage is distinct from other sectors of the Espírito Santo Basin where the preferential mode of reactivation is by upwards vertical propagation. Reactivation of faults above a Mid-Eocene unconformity is also scarce in the study area. Conversely, two halokinetic episodes dated as Cretaceous and Paleogene are interpreted below a Mid-Eocene unconformity. This work is important as it recognises the juxtaposition of permeable strata across faults as marking the generation of fault corridors linking adjacent salt structures. In such a setting, fault modelling shows that fluid will migrate towards the shallower salt structures along the fault corridors first identified in this work.

Marine forearc extension in the Hikurangi Margin: New insights from high-resolution 3D seismic data

NASA Astrophysics Data System (ADS)

Böttner, Christoph; Gross, Felix; Geersen, Jacob; Mountjoy, Joshu; Crutchley, Gareth; Krastel, Sebastian

2017-04-01

In subduction zones upper-plate normal faults have long been considered a tectonic feature primarily associated with erosive margins. However, increasing data coverage has proven that similar features also occur in accretionary margins, such as Cascadia, Makran, Nankai or Central Chile, where kinematics are dominated by compression. Considering their wide distribution there is, without doubt, a significant lack of qualitative and quantitative knowledge regarding the role and importance of normal faults and zones of extension for the seismotectonic evolution of accretionary margins. We use a high-resolution 3D P-Cable seismic volume from the Hikurangi Margin acquired in 2014 to analyze the spatial distribution and mechanisms of upper-plate normal faulting. The study area is located at the upper continental slope in the area of the Tuaheni landslide complex. In detail we aim to (1) map the spatial distribution of normal faults and characterize their vertical throws, strike directions, and dip angles; (2) investigate their possible influence on fluid migration in an area, where gas hydrates are present; (3) discuss the mechanisms that may cause extension of the upper-slope in the study area. Beneath the Tuaheni Landslide Complex we mapped about 200 normal faults. All faults have low displacements (<15 m) and dip at high (> 65°) angles. About 71% of the faults dip landward. We found two main strike directions, with the majority of faults striking 350-10°, parallel to the deformation front. A second group of faults strikes 40-60°. The faults crosscut the BSR, which indicates the base of the gas hydrate zone. In combination with seismically imaged bright-spots and pull-up structures, this indicates that the normal faults effectively transport fluids vertically across the base of the gas hydrate zone. Localized uplift, as indicated by the presence of the Tuaheni Ridge, might support normal faulting in the study area. In addition, different subduction rates across the margin may also favor extension between the segments. Future work will help to further untangle the mechanisms that cause extension of the upper continental slope.

History of displacement along Ste. Genevieve Fault Zone, Southwestern Illinois

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

Schwalb, H.R.

1983-09-01

The Ste. Genevieve fault zone extends eastward from Missouri across the Mississippi River into Jackson County, Illinois, about 75 mi (120 km) southeast of St. Louis. Outcrop studies have dated movement along portions of the zone as pre-Middle Devonian, post-Mississippian, and post-Pennsylvanian. Present displacement is down to the north and east with throw ranging up to 3,000 ft (915 m). However, pre-Middle Devonian movement was down to the south and west. The present upthrown block shows no evidence of vertical movement during the Cambrian and Ordovician. Nor is there any indication that the fault zone was part of the northernmore » border of the Reelfoot basin, where earliest Paleozoic sediments infilled an aulacogen at the northern end of the Mississippi embayment.« less

Verbal instruction for correcting errors versus such instructions plus videotape replay on learning the overhand throw.

PubMed

Kernodle, M W; Johnson, R; Arnold, D R

2001-06-01

The influence of two methods of providing information to women, ages 19 to 22 years who were novices and learning the overhand throw with the nondominant arm, was examined. One group received verbal information on correcting errors, and a second group received the same information immediately prior to viewing a videotaped replay of a just completed throw. Performance was assessed quantitatively with respect to outcome (distance thrown) and qualitatively with respect to throwing form as measured on a 7-point rating scale by judges with a working knowledge of the overhand throw and with respect to throwing mechanics rated by a panel of experts in biomechanics using a scale of Leme and Shambes. Although the treatments led to better learning and performance, there was no significant difference between groups for distance thrown on the Leme and Shambes scale in Sessions 1-6 of 10 trials each on Session 7. The mean rating also indicated increased scores for both groups and better retention at posttest by the group receiving only verbal corrections. These results suggest that information provided by adding videotaped replay may be redundant and unnecessary for those in Sessions 1-6.

Fault kinematics and localised inversion within the Troms-Finnmark Fault Complex, SW Barents Sea

NASA Astrophysics Data System (ADS)

Zervas, I.; Omosanya, K. O.; Lippard, S. J.; Johansen, S. E.

2018-04-01

The areas bounding the Troms-Finnmark Fault Complex are affected by complex tectonic evolution. In this work, the history of fault growth, reactivation, and inversion of major faults in the Troms-Finnmark Fault Complex and the Ringvassøy Loppa Fault Complex is interpreted from three-dimensional seismic data, structural maps and fault displacement plots. Our results reveal eight normal faults bounding rotated fault blocks in the Troms-Finnmark Fault Complex. Both the throw-depth and displacement-distance plots show that the faults exhibit complex configurations of lateral and vertical segmentation with varied profiles. Some of the faults were reactivated by dip-linkages during the Late Jurassic and exhibit polycyclic fault growth, including radial, syn-sedimentary, and hybrid propagation. Localised positive inversion is the main mechanism of fault reactivation occurring at the Troms-Finnmark Fault Complex. The observed structural styles include folds associated with extensional faults, folded growth wedges and inverted depocentres. Localised inversion was intermittent with rifting during the Middle Jurassic-Early Cretaceous at the boundaries of the Troms-Finnmark Fault Complex to the Finnmark Platform. Additionally, tectonic inversion was more intense at the boundaries of the two fault complexes, affecting Middle Triassic to Early Cretaceous strata. Our study shows that localised folding is either a product of compressional forces or of lateral movements in the Troms-Finnmark Fault Complex. Regional stresses due to the uplift in the Loppa High and halokinesis in the Tromsø Basin are likely additional causes of inversion in the Troms-Finnmark Fault Complex.

Co-seismic and cumulative slip along the Kokoxili Mw 7.9 earthquake rupture (Kunlun Fault, northeastern Tibet)

NASA Astrophysics Data System (ADS)

van der Woerd, J.; Klinger, Y.; Xu, X.; Ledortz, K.; Tapponnier, P.; Li, H.; King, G.; Ma, W.; Chen, W.

2009-04-01

Co-seismic slip values along a strike-slip rupture are found to be very irregular with variations up to one order of magnitude. Data usually scattered and sparse, are more dense and continuous with slip functions derived from InSAR or image correlations. Whether the fast variations in slip along strike reveals long-lived structures of the fault plane at depth, only incomplete slip at the surface or inelastic accommodation of slip remains debated. In addition, how these slip disparities are accommodated with time is unclear. The surface breaks of the Kokoxili Mw 7.9 event sytematically follow the geomorphic trace of the fault, which bears evidence for cumulative displacements. In the epicentral area, the rupture steps along the highest ice-capped summit of the region, the Buka Daban Feng. Evidence for normal fault breaks, left-lateral ruptures and steep triangular facets indicate that the Buka Daban Feng, a 40 km-long range reaching about 6800 m a.s.l. formed as a result of continuous oblique left-normal faulting. Normal faulting is attested by hanging glaciers, a steep southeastern flank and hot springs along coseismic and cumulative surface ruptures. Left-lateral movement along the main oblique normal fault has displaced the distal frontal moraines of almost all glacial valleys. West of the Buka Daban Feng, the western most ruptured strand is continuous between Kushiwan and Tayang lakes (about 60 km long) with coseismic left-lateral offsets reaching 4-5 m. To the east, at one site, the rupture splays into 4 main, N90°E-striking strands across a 1200x300m pull-apart. Three strands show right-stepping scarps with maximum throws of 1 m. The northern strand shows 3 m of purely normal throw. On NS profiles, the coseismic subsidence of the pull-apart floor was about 2 m, 1/10th of its 20 m depth, consistent with the repetition of 10 comparable earthquakes. East of the pull-apart 5 +/- 0.2 m sinistral slip are measured on the single stranded rupture. A similar coseismic sinistral slip value (4.8 +/- 0.4 m), with a thrust throw of 0.75 m, is found across two lake shorelines (1 and 2.3 meters above lake level), about 1.5 km farther east. At one river channel site, 15 km farther east, we measured a larger coseismic sinistral offset. The lowest terrace riser, between the active river bed and the lowest terrace is offset by about 10 m. Two older terrace risers show cumulative offsets twice as large (about 20 m). The largest cumulative offset measured reaches 50 m. Thirty kilometers yet farther east, near a glacial outlet at the foot of the Yuxi Shan, 4 distinct rills are offset by 3.5 m along the main surface break while smaller offsets (1-1.5 m) characterize a secondary break 250 m southwards. We have investigated in more detail the co-seismic and paleo-seismic slip near the central part of the rupture, where a set of about 10 inset terraces is used to infer the slip history of the fault. The particularly low co-seismic slip value at the site, about 2.4 +/- 0.6 m, lower than the value derived from Spot image correlation or from Insar, follows a maximum slip value of about 8 m only a few kilometres to the west. Site interpretation from field data, total station measurements and high resolution Ikonos images allow to reconstruct the different riser offsets across the damaged rupture zone. 10Be cosmogenic nuclide exposure ages of cobbles from the surface of the terraces allow to constrain the age the terraces and to infer an average slip-rate of 10-15 mm/yr in good agreement with previous results along the fault. When a characteristic slip model is considered, and depending of the measurement method or location of coseismic slip, the recurrence time for events comparable to the Mw 7.9 Kokoxili event may vary from 200 to 800 years.

Structure of a normal seismogenic fault zone in carbonates: The Vado di Corno Fault, Campo Imperatore, Central Apennines (Italy)

NASA Astrophysics Data System (ADS)

Demurtas, Matteo; Fondriest, Michele; Balsamo, Fabrizio; Clemenzi, Luca; Storti, Fabrizio; Bistacchi, Andrea; Di Toro, Giulio

2016-09-01

The Vado di Corno Fault Zone (VCFZ) is an active extensional fault cutting through carbonates in the Italian Central Apennines. The fault zone was exhumed from ∼2 km depth and accommodated a normal throw of ∼2 km since Early-Pleistocene. In the studied area, the master fault of the VCFZ dips N210/54° and juxtaposes Quaternary colluvial deposits in the hangingwall with cataclastic dolostones in the footwall. Detailed mapping of the fault zone rocks within the ∼300 m thick footwall-block evidenced the presence of five main structural units (Low Strain Damage Zone, High Strain Damage Zone, Breccia Unit, Cataclastic Unit 1 and Cataclastic Unit 2). The Breccia Unit results from the Pleistocene extensional reactivation of a pre-existing Pliocene thrust. The Cataclastic Unit 1 forms a ∼40 m thick band lining the master fault and recording in-situ shattering due to the propagation of multiple seismic ruptures. Seismic faulting is suggested also by the occurrence of mirror-like slip surfaces, highly localized sheared calcite-bearing veins and fluidized cataclasites. The VCFZ architecture compares well with seismological studies of the L'Aquila 2009 seismic sequence (mainshock MW 6.1), which imaged the reactivation of shallow-seated low-angle normal faults (Breccia Unit) cut by major high-angle normal faults (Cataclastic Units).

Long-term changes to river regimes prior to late Holocene coseismic faulting, Canterbury, New Zealand

NASA Astrophysics Data System (ADS)

Campbell, Jocelyn K.; Nicol, Andrew; Howard, Matthew E.

2003-09-01

Two sites are described from range front faults along the foothills of the Southern Alps of New Zealand, where apparently a period of 200-300 years of accelerated river incision preceded late Holocene coseismic ruptures, each probably in excess of M w 7.5. They relate to separate fault segments and seismic events on a transpressive system associated with fault-driven folding, but both show similar evidence of off-plane aseismic deformation during the downcutting phase. The incision history is documented by the ages, relative elevations and profiles of degradation terraces. The surface dating is largely based on the weathering rind technique of McSaveney (McSaveney, M.J., 1992. A Manual for Weathering-rind Dating of Grey Sandstones of the Torlesse Supergroup, New Zealand. 92/4, Institute of Geological and Nuclear Sciences), supported by some consistent radiocarbon ages. On the Porters Pass Fault, drainage from Red Lakes has incised up to 12 m into late Pleistocene recessional outwash, but the oldest degradation terrace surface T I is dated at only 690±50 years BP. The upper terraces T I and T II converge uniformly downstream right across the fault trace, but by T III the terrace has a reversed gradient upstream. T II and T III break into multiple small terraces on the hanging wall only, close to the fault trace. Continued backtilting during incision caused T IV to diverge downstream relative to the older surfaces. Coseismic faulting displaced T V and all the older terraces by a metre high reverse scarp and an uncertain right lateral component. This event cannot be younger than a nearby ca. 500 year old rock avalanche covering the trace. The second site in the middle reaches of the Waipara River valley involves the interaction of four faults associated with the Doctors Anticline. The main river and tributaries have incised steeply into a 2000 year old mid-Holocene, broad, degradation surface downcutting as much as 55 m. Beginning approximately 600 years ago accelerating incision eventually attained rates in excess of 100 mm/year in those reaches closely associated with the Doctors Anticline and related thrust and transfer faults. All four faults ruptured, either synchronously or sequentially, between 250 and 400 years ago when the river was close to 8 m above its present bed. Better cross-method checks on dating would eliminate some uncertainties, but the apparent similarities suggest a pattern of precursor events initiated by a period of base level drop extending for several kilometres across the structure, presumably in response to general uplift. Over time, deformation is concentrated close to the fault zone causing tilting of degradation terraces, and demonstrably in the Waipara case at least, coseismic rupture is preceded by marked acceleration of the downcutting rate. Overall base level drop is an order of magnitude greater than the throw on the eventual fault scarp. The Ostler Fault (Van Dissen et al., 1993) demonstrates that current deformation is taking place on similar thrust-fault driven folding in the Southern Alps. Regular re-levelling since 1966 has shown uplift rates of 1.0-1.5 mm/year at the crest of a 1-2 km half wave length anticline, but this case also illustrates the general problem of interpreting the significance of rates derived from geophysical monitoring relative to the long term seismic cycle. If the geomorphic signals described can be shown to hold for other examples, then criteria for targeting faults approaching the end of the seismic cycle in some tectonic settings may be possible.

Role of the Precambrian Mughese Shear Zone on Cenozoic faulting along the Rukwa-Malawi Rift segment of the East African Rift System

NASA Astrophysics Data System (ADS)

Heilman, E.; Kolawole, F.; Mayle, M.; Atekwana, E. A.; Abdelsalam, M. G.

2017-12-01

We address the longstanding question of the role of long-lived basement structures in strain accommodation within active rift systems. Studies have highlighted the influence of pre-existing zones of lithospheric weakness in modulating faulting and fault kinematics. Here, we investigate the role of the Neoproterozoic Mughese Shear Zone (MSZ) in Cenozoic rifting along the Rukwa-Malawi rift segment of the East African Rift System (EARS). Detailed analyses of Shuttle Radar Topography Mission (SRTM) DEM and filtered aeromagnetic data allowed us to determine the relationship between rift-related basement-rooted normal faults and the MSZ fabric extending along the southern boundary of the Rukwa-Malawi Rift North Basin. Our results show that the magnetic lineaments defining the MSZ coincide with the collinear Rukwa Rift border fault (Ufipa Fault), a dextral strike-slip fault (Mughese Fault), and the North Basin hinge-zone fault (Mbiri Fault). Fault-scarp and minimum fault-throw analyses reveal that within the Rukwa Rift, the Ufipa Border Fault has been accommodating significant displacement relative to the Lupa Border Fault, which represents the northeastern border fault of the Rukwa Rift. Our analysis also shows that within the North Basin half-graben, the Mbiri Fault has accommodated the most vertical displacement relative to other faults along the half-graben hinge zone. We propose that the Cenozoic reactivation along the MSZ facilitated significant normal slip displacement along the Ufipa Border Fault and the Mbiri Fault, and minor dextral strike-slip between the two faults. We suggest that the fault kinematics along the Rukwa-Malawi Rift is the result of reactivation of the MSZ through regional oblique extension.

Biomechanical analysis of the sidearm throwing motion for distance of a flying disc: a comparison of skilled and unskilled ultimate players.

PubMed

Sasakawa, Kei; Sakurai, Shinji

2008-09-01

Joint angles of the throwing limb were examined from the acceleration phase up until release for the sidearm throwing motion when using a flying disc. 17 individuals (ten skilled, seven unskilled) threw a disc as far as possible ten times. Throwing motions were recorded using three-dimensional high-speed videography. The initial condition of disc release and joint angle kinematics of the upper limb during the throwing motion were obtained. Mean (+/- standard deviation) throwing distance and disc spin rate were significantly greater for skilled throwers (51.4 +/- 6.6 m, 12.9 +/- 1.3 rps) than for unskilled throwers (29.5 +/- 7.6 m, 9.4 +/- 1.3 rps), although there was no significant difference in initial velocity of the disc between the two groups (skilled: 21.7 +/- 1.7m/s; unskilled: 20.7 +/- 2.5m/s). A marked difference in motion of supination/pronation of the forearm before disc release was identified, with the forearm supinated in the final acceleration phase leading up to disc release for the unskilled participants, while the forearm was pronated in the same phase for the skilled participants. These differences in joint kinematics could be related to differences in disc spin rate, and thus led to the substantial differences in throwing distance.

Temporal evolution of fault systems in the Upper Jurassic of the Central German Molasse Basin: case study Unterhaching

NASA Astrophysics Data System (ADS)

Budach, Ingmar; Moeck, Inga; Lüschen, Ewald; Wolfgramm, Markus

2018-03-01

The structural evolution of faults in foreland basins is linked to a complex basin history ranging from extension to contraction and inversion tectonics. Faults in the Upper Jurassic of the German Molasse Basin, a Cenozoic Alpine foreland basin, play a significant role for geothermal exploration and are therefore imaged, interpreted and studied by 3D seismic reflection data. Beyond this applied aspect, the analysis of these seismic data help to better understand the temporal evolution of faults and respective stress fields. In 2009, a 27 km2 3D seismic reflection survey was conducted around the Unterhaching Gt 2 well, south of Munich. The main focus of this study is an in-depth analysis of a prominent v-shaped fault block structure located at the center of the 3D seismic survey. Two methods were used to study the periodic fault activity and its relative age of the detected faults: (1) horizon flattening and (2) analysis of incremental fault throws. Slip and dilation tendency analyses were conducted afterwards to determine the stresses resolved on the faults in the current stress field. Two possible kinematic models explain the structural evolution: One model assumes a left-lateral strike slip fault in a transpressional regime resulting in a positive flower structure. The other model incorporates crossing conjugate normal faults within a transtensional regime. The interpreted successive fault formation prefers the latter model. The episodic fault activity may enhance fault zone permeability hence reservoir productivity implying that the analysis of periodically active faults represents an important part in successfully targeting geothermal wells.

The role of bed-parallel slip in the development of complex normal fault zones

NASA Astrophysics Data System (ADS)

Delogkos, Efstratios; Childs, Conrad; Manzocchi, Tom; Walsh, John J.; Pavlides, Spyros

2017-04-01

Normal faults exposed in Kardia lignite mine, Ptolemais Basin, NW Greece formed at the same time as bed-parallel slip-surfaces, so that while the normal faults grew they were intermittently offset by bed-parallel slip. Following offset by a bed-parallel slip-surface, further fault growth is accommodated by reactivation on one or both of the offset fault segments. Where one fault is reactivated the site of bed-parallel slip is a bypassed asperity. Where both faults are reactivated, they propagate past each other to form a volume between overlapping fault segments that displays many of the characteristics of relay zones, including elevated strains and transfer of displacement between segments. Unlike conventional relay zones, however, these structures contain either a repeated or a missing section of stratigraphy which has a thickness equal to the throw of the fault at the time of the bed-parallel slip event, and the displacement profiles along the relay-bounding fault segments have discrete steps at their intersections with bed-parallel slip-surfaces. With further increase in displacement, the overlapping fault segments connect to form a fault-bound lens. Conventional relay zones form during initial fault propagation, but with coeval bed-parallel slip, relay-like structures can form later in the growth of a fault. Geometrical restoration of cross-sections through selected faults shows that repeated bed-parallel slip events during fault growth can lead to complex internal fault zone structure that masks its origin. Bed-parallel slip, in this case, is attributed to flexural-slip arising from hanging-wall rollover associated with a basin-bounding fault outside the study area.

Crestal fault geometries reveal late halokinesis and collapse of the Samson Dome, Northern Norway: Implications for petroleum systems in the Barents Sea

NASA Astrophysics Data System (ADS)

Mattos, Nathalia H.; Alves, Tiago M.; Omosanya, Kamaldeen O.

2016-10-01

This paper uses 2D and high-quality 3D seismic reflection data to assess the geometry and kinematics of the Samson Dome, offshore Norway, revising the implications of the new data to hydrocarbon exploration in the Barents Sea. The study area was divided into three (3) zones in terms of fault geometries and predominant strikes. Displacement-length (D-x) and Throw-depth (T-z) plots showed faults to consist of several segments that were later dip-linked. Interpreted faults were categorised into three families, with Type A comprising crestal faults, Type B representing large E-W faults, and Type C consisting of polygonal faults. The Samson Dome was formed in three major stages: a) a first stage recording buckling of the post-salt overburden and generation of radial faults; b) a second stage involving dissolution and collapse of the dome, causing subsidence of the overburden and linkage of initially isolated fault segments; and c) a final stage in which large fault segments were developed. Late Cretaceous faults strike predominantly to the NW, whereas NE-trending faults comprise Triassic structures that were reactivated in a later stage. Our work provides scarce evidence for the escape of hydrocarbons in the Samson Dome. In addition, fault analyses based on present-day stress distributions indicate a tendency for 'locking' of faults at depth, with the largest leakage factors occurring close to the surface. The Samson Dome is an analogue to salt structures in the Barents Sea where oil and gas exploration has occurred with varied degrees of success.

Comparison of three types of full‐body compression garments on throwing and repeat‐sprint performance in cricket players

PubMed Central

Duffield, Rob; Portus, Marc

2007-01-01

Objective To compare the effects of three types of full‐body compression garments (Skins, Adidas and Under Armour) on repeat‐sprint and throwing performance in cricket players. Methods Following familiarisation, 10 male cricket players performed four randomised exercise sessions (3 garments and a control). Each session involved a 30 min repeat‐sprint exercise protocol comprising 20 m sprints every minute, separated by submaximal exercise. Throwing tests included a pre‐exercise and a postexercise maximal distance test and accuracy throwing tests. During each session, measures of heart rate, skin temperature, change in body mass, rate of perceived exertion and perceived muscle soreness were recorded. Capillary blood samples were analysed before and after exercise for lactate, pH, O2 saturation and O2 partial pressure, and 24 h after exercise for creatine kinase (CK). Ratings of perceived muscle soreness were also obtained 24 h after exercise. Results No significant differences (p>0.05) were evident in repeat‐sprint performance (10 m, 20 m time or total submaximal distance covered) or throwing performance (maximum distance or accuracy). No significant differences (p>0.05) were observed in heart rate, body mass change or blood measures during exercise. Significant differences (p<0.05) were observed by way of higher mean skin temperature, lower 24 h postexercise CK values and lower 24 h postexercise ratings of muscle soreness when wearing compression garments. Analysis between respective brands of compression garments revealed no statistical differences (p>0.05). Conclusions No benefit was noted when wearing compression garments for repeat‐sprint or throwing performance; however, the use of the garments as a recovery tool, when worn after exercise, may be beneficial to reduce postexercise trauma and perceived muscle soreness. PMID:17341589

Comparison of three types of full-body compression garments on throwing and repeat-sprint performance in cricket players.

PubMed

Duffield, Rob; Portus, Marc

2007-07-01

To compare the effects of three types of full-body compression garments (Skins, Adidas and Under Armour) on repeat-sprint and throwing performance in cricket players. Following familiarisation, 10 male cricket players performed four randomised exercise sessions (3 garments and a control). Each session involved a 30 min repeat-sprint exercise protocol comprising 20 m sprints every minute, separated by submaximal exercise. Throwing tests included a pre-exercise and a postexercise maximal distance test and accuracy throwing tests. During each session, measures of heart rate, skin temperature, change in body mass, rate of perceived exertion and perceived muscle soreness were recorded. Capillary blood samples were analysed before and after exercise for lactate, pH, O(2) saturation and O(2) partial pressure, and 24 h after exercise for creatine kinase (CK). Ratings of perceived muscle soreness were also obtained 24 h after exercise. No significant differences (p>0.05) were evident in repeat-sprint performance (10 m, 20 m time or total submaximal distance covered) or throwing performance (maximum distance or accuracy). No significant differences (p>0.05) were observed in heart rate, body mass change or blood measures during exercise. Significant differences (p<0.05) were observed by way of higher mean skin temperature, lower 24 h postexercise CK values and lower 24 h postexercise ratings of muscle soreness when wearing compression garments. Analysis between respective brands of compression garments revealed no statistical differences (p>0.05). No benefit was noted when wearing compression garments for repeat-sprint or throwing performance; however, the use of the garments as a recovery tool, when worn after exercise, may be beneficial to reduce postexercise trauma and perceived muscle soreness.

Development of partial rock veneers by root throw in a subalpine setting

USGS Publications Warehouse

Osterkamp, W.R.; Toy, T.J.; Lenart, M.T.

2006-01-01

Rock veneers stabilize hillslope surfaces, occur especially in areas of immature soil, and form through a variety of process sets that includes root throw. Near Westcliffe, Colorado, USA, data were collected from a 20 ?? 500 m transect on the east slope of the Sangre de Cristo Mountains. Ages of pit/mound complexes with rock fragments exposed at the surface by root throw ranged from recent (freshly toppled tree) to unknown (complete tree decay). Calculations based on dimensions of the pit/mound complexes, estimated time of free topppling, sizes of exposed rock fragments, and percentage rock covers at pit/mound complexes, as well as within the transect area, indicate that recent rates of root throw have resulted in only partial rock veneering since late Pleistocene deglaciation. Weathering of rock fragments prevent development of an extensive rock veneer and causes a balance, achieved within an estimated 700 years, between the rates of rock-fragment exposure by root throw and clast disintegration by chemical reduction. The estimated rate of rock-fragment reduction accounts for part of the fluvial sediment yields observed for forested subalpine areas of western North America. Copyright ?? 2005 John Wiley & Sons, Ltd.

Multiple late Holocene earthquakes along the Reelfoot fault, central New Madrid seismic zone

NASA Astrophysics Data System (ADS)

Kelson, Keith I.; Simpson, Gary D.; Vanarsdale, Roy B.; Haraden, Colleen C.; Lettis, William R.

1996-03-01

The Reelfoot fault is an east vergent, reverse fault underlying the Lake County uplift, a low-amplitude, late Holocene anticline bordered on the east by the 32-km-long Reelfoot scarp. Fluvial deposits across the scarp define an 8-m-high, east facing monocline. Most near-surface deformation along the scarp is accommodated via folding rather than faulting. We interpret the scarp as a fault-propagation fold developed over a west dipping reverse fault interpreted from shallow seismic reflection data. Trench exposures provide evidence for three episodes of deformation along the Reelfoot fault within the past approximately 2400 years, between A.D. 780 and 1000, between A.D. 1260 and 1650, and during A.D. 1812. Our best estimate of the average recurrence interval for deformation along the scarp is 400-500 years. Each episode of deformation had a slightly different style. The third most recent event produced a small graben a few tens of centimeters deep in the hanging wall of the reverse fault. The second most recent earthquake produced about 1.3 m of throw in the graben, as well as folding along the updip projection of the reverse fault and development of the scarp. These relations suggest that graben development increased through time concomitant with growth of the monocline or that the events are of different magnitude. The 1811-1812 episode of deformation produced abundant liquefaction, prominent folding of fluvial strata along the scarp, and minor faulting in the graben.

Geophysical study of the Ota-VF Xira-Lisbon-Sesimbra fault zone and the lower Tagus Cenozoic basin

NASA Astrophysics Data System (ADS)

Carvalho, João; Rabeh, Taha; Bielik, Miroslav; Szalaiová, Eva; Torres, Luís; Silva, Marisa; Carrilho, Fernando; Matias, Luís; Miranda, Jorge Miguel

2011-09-01

This paper focuses on the interpretation of seismic reflection, gravimetric, topographic, deep seismic refraction and seismicity data to study the recently proposed Ota-Vila Franca de Xira-Lisbon-Sesimbra (OVLS) fault zone and the lower Tagus Cenozoic basin (LTCB). The studied structure is located in the lower Tagus valley (LTV), an area with over 2 million inhabitants that has experienced historical earthquakes which caused significant damage and economical losses (1344, 1531 and 1909 earthquakes) and whose tectonic sources are thought to be local but mostly remain unknown. This study, which is intended as a contribution to improve the seismic hazard of the area and the neotectonics of the region, shows that the above-proposed fault zone is probably a large crustal thrust fault that constitutes the western limit of the LTCB. Gravimetric, deep refraction and seismic reflection data suggest that the LTCB is a foreland basin, as suggested previously by some authors, and that the OVLS northern and central sectors act as the major thrusts. The southern sector fault has been dominated by strike-slip kinematics due to a different orientation to the stress field. Indeed, geological outcrop and seismic reflection data interpretation suggests that, based on fault geometry and type of deformation at depth, the structure is composed of three major segments. These data suggest that these segments have different kinematics in agreement with their orientation to the regional stress field. The OVLS apparently controls the distribution of the seismicity in the area. Geological and geophysical information previously gathered also points that the central segment is active into the Quaternary. The segment lengths vary between 20 and 45 km. Since faults usually rupture only by segments, maximum expectable earthquake magnitudes and other parameters have been calculated for the three sectors of the OVLS fault zone using empirical relationships between earthquake statistics and geological parameters available from the literature. Calculated slip rates are compatible with previous estimates for the area (0.33 mm yr-1). A more accurate estimation of the OVLS throw in the Quaternary sediments is therefore of vital importance for a more accurate evaluation of the seismic hazard of the area.

Shallow subsurface imaging of the Piano di Pezza active normal fault (central Italy) by high-resolution refraction and electrical resistivity tomography coupled with time domain electromagnetic data

NASA Astrophysics Data System (ADS)

Villani, Fabio; Tulliani, Valerio; Fierro, Elisa; Sapia, Vincenzo; Civico, Riccardo

2015-04-01

The Piano di Pezza fault is the north-westernmost segment of the >20 km long Ovindoli-Pezza active normal fault-system (central Italy). Although existing paleoseismic data document high vertical Holocene slip rates (~1 mm/yr) and a remarkable seismogenic potential of this fault, its subsurface setting and Pleistocene cumulative displacement are still poorly known. We investigated for the first time by means of high-resolution seismic and electrical resistivity tomography coupled with time domain electromagnetic (TDEM) measurements the shallow subsurface of a key section of the Piano di Pezza fault. Our surveys cross a ~5 m-high fault scarp that was generated by repeated surface-rupturing earthquakes displacing some Late Holocene alluvial fans. We provide 2-D Vp and resistivity images which clearly show significant details of the fault structure and the geometry of the shallow basin infill material down to 50 m depth. We can estimate the dip (~50°) and the Holocene vertical displacement of the master fault (~10 m). We also recognize in the hangingwall some low-velocity/low-resistivity regions that we relate to packages of colluvial wedges derived from scarp degradation, which may represent the record of several paleo-earthquakes older than the Late Holocene events previously recognized by paleoseismic trenching. Conversely, due to the limited investigation depth of seismic and electrical tomography, the estimation of the cumulative amount of Pleistocene throw is hampered. Therefore, to increase the depth of investigation, we performed 7 TDEM measurements along the electrical profile using a 50 m loop size both in central and offset configuration. The recovered 1-D resistivity models show a good match with 2-D resistivity images in the near surface. Moreover, TDEM inversion results indicate that in the hangingwall, ~200 m away from the surface fault trace, the carbonate pre-Quaternary basement may be found at ~90-100 m depth. The combined approach of electrical and seismic data coupled with TDEM measurements provides a robust constraint to the Piano di Pezza fault cumulative offset. Our data are useful for better reconstructing the deep structural setting of the Piano di Pezza basin and assessing the role played by extensional tectonics in its Quaternary evolution.

Using Markov Models of Fault Growth Physics and Environmental Stresses to Optimize Control Actions

NASA Technical Reports Server (NTRS)

Bole, Brian; Goebel, Kai; Vachtsevanos, George

2012-01-01

A generalized Markov chain representation of fault dynamics is presented for the case that available modeling of fault growth physics and future environmental stresses can be represented by two independent stochastic process models. A contrived but representatively challenging example will be presented and analyzed, in which uncertainty in the modeling of fault growth physics is represented by a uniformly distributed dice throwing process, and a discrete random walk is used to represent uncertain modeling of future exogenous loading demands to be placed on the system. A finite horizon dynamic programming algorithm is used to solve for an optimal control policy over a finite time window for the case that stochastic models representing physics of failure and future environmental stresses are known, and the states of both stochastic processes are observable by implemented control routines. The fundamental limitations of optimization performed in the presence of uncertain modeling information are examined by comparing the outcomes obtained from simulations of an optimizing control policy with the outcomes that would be achievable if all modeling uncertainties were removed from the system.

Normal faulting and mass movement during ridge subduction inferred from porosity transition and zeolitization in the Costa Rica subduction zone

NASA Astrophysics Data System (ADS)

Hamahashi, Mari; Screaton, Elizabeth; Tanikawa, Wataru; Hashimoto, Yoshitaka; Martin, Kylara; Saito, Saneatsu; Kimura, Gaku

2017-07-01

Subduction of the buoyant Cocos Ridge offshore the Osa Peninsula, Costa Rica substantially affects the upper plate structure through a variety of processes, including outer forearc uplift, erosion, and focused fluid flow. To investigate the nature of a major seismic reflector (MSR) developed between slope sediments (late Pliocene-late Pleistocene silty clay) and underlying higher velocity upper plate materials (late Pliocene-early Pleistocene clayey siltstone), we infer possible mechanisms of sediment removal by examining the consolidation state, microstructure, and zeolite assemblages of sediments recovered from Integrated Ocean Drilling Program Expedition 344 Site U1380. Formation of Ca-type zeolites, laumontite and heulandite, inferred to form in the presence of Ca-rich fluids, has caused porosity reduction. We adjust measured porosity values for these pore-filling zeolites and evaluated the new porosity profile to estimate how much material was removed at the MSR. Based on the composite porosity-depth curve, we infer the past burial depth of the sediments directly below the MSR. The corrected and uncorrected porosity-depth curves yield values of 800 ± 70 m and 900 ± 70 m, respectively. We argue that deposition and removal of this entire estimated thickness in 0.49 Ma would require unrealistically large sedimentation rates and suggest that normal faulting at the MSR must contribute. The porosity offset could be explained with maximum 250 ± 70 m of normal fault throw, or 350 ± 70 m if the porosity were not corrected. The porosity correction significantly reduces the amount of sediment removal needed for the combination of mass movement and normal faulting that characterize the slope in this margin.

Construction Foundation Report for Seepage Control Adits Abiquiu Dam and Reservoir, New Mexico

DTIC Science & Technology

1990-02-02

by broad folds and gentle regional dips to the north and west. Steeply dipping normal faults with a general north to northeast trend are common and...often exhibit throws in excess of 200 feet. Jointing is generally north-west to north-east and are nearly vertical to vertical. [1] The close of the...numerous minor joints. Joints faces in the mudstone are commonly striated and slickensided in random orientations. [1] The Agua Zarca Sandstone member of

Hot, deep origin of petroleum: deep basin evidence and application

USGS Publications Warehouse

Price, Leigh C.

1978-01-01

Use of the model of a hot deep origin of oil places rigid constraints on the migration and entrapment of crude oil. Specifically, oil originating from depth migrates vertically up faults and is emplaced in traps at shallower depths. Review of petroleum-producing basins worldwide shows oil occurrence in these basins conforms to the restraints of and therefore supports the hypothesis. Most of the world's oil is found in the very deepest sedimentary basins, and production over or adjacent to the deep basin is cut by or directly updip from faults dipping into the basin deep. Generally the greater the fault throw the greater the reserves. Fault-block highs next to deep sedimentary troughs are the best target areas by the present concept. Traps along major basin-forming faults are quite prospective. The structural style of a basin governs the distribution, types, and amounts of hydrocarbons expected and hence the exploration strategy. Production in delta depocenters (Niger) is in structures cut by or updip from major growth faults, and structures not associated with such faults are barren. Production in block fault basins is on horsts next to deep sedimentary troughs (Sirte, North Sea). In basins whose sediment thickness, structure and geologic history are known to a moderate degree, the main oil occurrences can be specifically predicted by analysis of fault systems and possible hydrocarbon migration routes. Use of the concept permits the identification of significant targets which have either been downgraded or ignored in the past, such as production in or just updip from thrust belts, stratigraphic traps over the deep basin associated with major faulting, production over the basin deep, and regional stratigraphic trapping updip from established production along major fault zones.

3-D GPR data analysis for high-resolution imaging of shallow subsurface faults: the Mt Vettore case study (Central Apennines, Italy)

NASA Astrophysics Data System (ADS)

Ercoli, Maurizio; Pauselli, Cristina; Frigeri, Alessandro; Forte, Emanuele; Federico, Costanzo

2014-07-01

The activation of Late Quaternary faults in the Central Apennines (Italy) could generate earthquakes with magnitude of about 6.5, and the Monte Vettore fault system probably belongs to the same category of seismogenetic faults. Such structure has been defined `silent', because of its geological and geomorphological evidences of past activation, but the absence of historical records in the seismic catalogues to be associated with its activation. The `Piano di Castelluccio' intramountain basin, resulting from the Quaternary activity of normal faults, is characterized by a secondary fault strand highlighted by a NW-SE fault scarp: it has been already studied through palaeoseismological trenches, which highlighted evidences of Quaternary shallow faulting due to strong earthquakes, and through a 2-D ground penetrating radar (GPR) survey, showing the first geophysical signature of faulting for this site. Within the same place, a 3-D GPR volume over a 20 × 20 m area has been collected. The collection of radar echoes in three dimensions allows to map both the vertical and lateral continuity of shallow geometries of the fault zone (Fz), imaging features with high resolution, ranging from few metres to centimetres and therefore imaging also local variations at the microscale. Several geophysical markers of faulting, already highlighted on this site, have been taken as reference to plan the 3-D survey. In this paper, we provide the first 3-D subsurface imaging of an active shallow fault belonging to the Umbria-Marche Apennine highlighting the subsurface fault geometry and the stratigraphic sequence up to a depth of about 5 m. From our data, geophysical faulting signatures are clearly visible in three dimensions: diffraction hyperbolas, truncations of layers, local attenuated zones and varying dip of the layers have been detected within the Fz. The interpretation of the 3-D data set provided qualitative and quantitative geological information in addition to the fault location, like its geometry, boundaries and an estimation of the fault throw.

High-resolution seismic reflection imaging of growth folding and shallow faults beneath the Southern Puget Lowland, Washington State

USGS Publications Warehouse

Clement, C.R.; Pratt, T.L.; Holmes, M.L.; Sherrod, B.L.

2010-01-01

Marine seismic reflection data from southern Puget Sound, Washington, were collected to investigate the nature of shallow structures associated with the Tacoma fault zone and the Olympia structure. Growth folding and probable Holocene surface deformation were imaged within the Tacoma fault zone beneath Case and Carr Inlets. Shallow faults near potential field anomalies associated with the Olympia structure were imaged beneath Budd and Eld Inlets. Beneath Case Inlet, the Tacoma fault zone includes an ???350-m wide section of south-dipping strata forming the upper part of a fold (kink band) coincident with the southern edge of an uplifted shoreline terrace. An ???2 m change in the depth of the water bottom, onlapping postglacial sediments, and increasing stratal dips with increasing depth are consistent with late Pleistocene to Holocene postglacial growth folding above a blind fault. Geologic data across a topographic lineament on nearby land indicate recent uplift of late Holocene age. Profiles acquired in Carr Inlet 10 km to the east of Case Inlet showed late Pleistocene or Holocene faulting at one location with ???3 to 4 m of vertical displacement, south side up. North of this fault the data show several other disruptions and reflector terminations that could mark faults within the broad Tacoma fault zone. Seismic reflection profiles across part of the Olympia structure beneath southern Puget Sound show two apparent faults about 160 m apart having 1 to 2 m of displacement of subhorizontal bedding. Directly beneath one of these faults, a dipping reflector that may mark the base of a glacial channel shows the opposite sense of throw, suggesting strike-slip motion. Deeper seismic reflection profiles show disrupted strata beneath these faults but little apparent vertical offset, consistent with strike-slip faulting. These faults and folds indicate that the Tacoma fault and Olympia structure include active structures with probable postglacial motion.

High-resolution seismic reflection imaging of growth folding and shallow faults beneath the Southern Puget Lowland, Washington State

USGS Publications Warehouse

Odum, Jackson K.; Stephenson, William J.; Pratt, Thomas L.; Blakely, Richard J.

2016-01-01

Marine seismic reflection data from southern Puget Sound, Washington, were collected to investigate the nature of shallow structures associated with the Tacoma fault zone and the Olympia structure. Growth folding and probable Holocene surface deformation were imaged within the Tacoma fault zone beneath Case and Carr Inlets. Shallow faults near potential field anomalies associated with the Olympia structure were imaged beneath Budd and Eld Inlets. Beneath Case Inlet, the Tacoma fault zone includes an ∼350-m wide section of south-dipping strata forming the upper part of a fold (kink band) coincident with the southern edge of an uplifted shoreline terrace. An ∼2 m change in the depth of the water bottom, onlapping postglacial sediments, and increasing stratal dips with increasing depth are consistent with late Pleistocene to Holocene postglacial growth folding above a blind fault. Geologic data across a topographic lineament on nearby land indicate recent uplift of late Holocene age. Profiles acquired in Carr Inlet 10 km to the east of Case Inlet showed late Pleistocene or Holocene faulting at one location with ∼3 to 4 m of vertical displacement, south side up. North of this fault the data show several other disruptions and reflector terminations that could mark faults within the broad Tacoma fault zone. Seismic reflection profiles across part of the Olympia structure beneath southern Puget Sound show two apparent faults about 160 m apart having 1 to 2 m of displacement of subhorizontal bedding. Directly beneath one of these faults, a dipping reflector that may mark the base of a glacial channel shows the opposite sense of throw, suggesting strike-slip motion. Deeper seismic reflection profiles show disrupted strata beneath these faults but little apparent vertical offset, consistent with strike-slip faulting. These faults and folds indicate that the Tacoma fault and Olympia structure include active structures with probable postglacial motion.

Stress-sensitivity of The Hydraulic Properties of A Fault Gouge

NASA Astrophysics Data System (ADS)

Harrington, J. F.; Horseman, S. T.; Hama, K.; Metcalfe, R.

Tono Mine is located about 350 km southwest of Tokyo and is the site of the most extensive uranium deposits in Japan. The geological setting comprises Tertiary (Mizu- nami Group) sedimentary rocks overlying Cretaceous granitic basement rocks. In as- cending order, the sedimentary rocks are the Toki Lignite-bearing Formation (con- glomerate, interbedded sandstone and mudstone), the Akeyo Formation (tuffaceous sandstone) and the Oidawara Formation (siltstone and mudstone). The Tsukiyoshi Fault cuts through this sequence and is a reverse fault, dipping to the south at 60- 70 degrees, with a throw of about 30 metres. As part of its hydrogeological studies, JNC is evaluating the impact of the fault on groundwater flow in the Tertiary sedi- ments. A sample was taken from a borehole in the NATM Drift, where the fault zone contains gouge material with two clay-bearing layers around 2 to 3 cm thick, separated by a 10 to 20 cm thick layer of unconsolidated fine sandy material. The sample was obtained using a triple-tube core barrel fitted with a split sample tube and a diamond bit. A specimen was prepared and consolidated at successive effective stress levels of 2, 6 and 12 MPa. The plot of void ratio against the logarithm of effective stress was found to be sensibly linear with a negative slope, kappa, of 0.036 rising to 0.044 at higher stress levels. The evidence suggests that the gouge is overconsolidated. Hy- draulic conductivity and specific storage were also measured at each stress level using the constant flow rate method. Hydraulic conductivity was found to be strongly stress sensitive, falling from 1.84 x 10-12 m.s-1 at 2 MPa to 7.9 x 10-14 m.s-1 at 12 MPa. Specific storage values were analysed using the critical state soil mechanics approach assuming a stress-dependent pore compressibility. Reasonable agreement was found between the theoretical curve with kappa = 0.036 and the measured values.

Surface expression of intraplate postglacial faults in Sweden: from LiDAR data

NASA Astrophysics Data System (ADS)

Abduljabbar, Mawaheb; Ask, Maria; Bauer, Tobias; Lund, Björn; Smith, Colby; Mikko, Henrik; Munier, Raymond

2016-04-01

Large intraplate earthquakes, up to magnitude 8.0±0.3 (Lindblom et al. 2015) are inferred to have occurred in northern Fennoscandia at the end of, or just after the Weichselian deglaciation. More than a dozen large so-called postglacial faults (PGF) have been found in the region. The present-day microseismic activity is rather high in north Sweden, and there is a correlation between microseismicity and mapped PGF scarps: 71% of the observed earthquakes north of 66°N locate within 30 km to the southeast and 10 km to the northwest of PGFs (Lindblom et al., 2015). Surface expressions of PGFs in Sweden have mainly been mapped using aerial photogrammetry and trenching (e.g. Lagerbäck & Sundh 2008). Their detailed surface geometry may be investigated using the new high-resolution elevation model of Sweden (NNH) that has a vertical- and lateral resolution of 2 m and 0.25 m, respectively. With NNH data, known PGFs have been modified, and a number of new potential PGFs have been identified (Smith et al. 2014; Mikko et al. 2015). However, the detailed variation of their surface expression remains to be determined. Our main objective is to constrain the strike and surface offset (i.e., apparent vertical throw because of soil cover overlays the bedrock) across the PGF scarps. We anticipate using the results to constrain direction of fault motion and paleomagnitudes of PGFs, and in numerical analyzes to investigate the nature of PGFs. We have developed a methodology for analyzing PGF-geomorphology from LiDAR data using two main software platforms (Ask et al. 2015): (1) Move2015 by Midland Valley has been used for constructing 3D models of the surface traces of the PGFs to determine apparent vertical throw. The apparent hanging- and footwall cut off lines are digitized, and subsequent computation of coordinates is rather time efficient and provide continuous data of fault and soil geomorphology that can be statistically analyzed; and (2) ArcGIS 10.3 by Esri has mostly been used to derive the slope model for the study area. We successfully tested the methodology within a limited area of the Pärvie fault zone, which is the longest known PGF in the world (Ask et al. 2015). Here, we apply the methodology to PGFs in northern Sweden. Additionally, we are planning to analyse PGFs within a virtual reality environment utilizing the GeoVisionary software platform by Virtalis Ltd. in order to increase accuracy and efficiency and to decrease modelling uncertainties. References Ask et al. 2015. Geomorphology of intraplate postglacial faults in Sweden. AGU, Abstract #83167 Lindblom, et al., 2015. Microearthquakes illuminate the deep structure of the endglacial Pärvie fault, northern Sweden. doi: 10.1093/gji/ggv112 Lagerbäck & Sundh, 2008. Early Holocene faulting and paleoseismicity in northern Sweden. http://resource.sgu.se/produkter/c/c836-rapport.pdf Mikko, et al. 2015. LiDAR-derived inventory of post-glacial fault scarps in Sweden. doi:10.1080/11035897.2015.1036360 Smith, et al., 2014. Surficial geology indicates early Holocene faulting and seismicity, central Sweden. doi: 10.1007/s00531-014-1025-6

Relationship between accuracy and complexity when learning underarm precision throwing.

PubMed

Valle, Maria Stella; Lombardo, Luciano; Cioni, Matteo; Casabona, Antonino

2018-06-12

Learning precision ball throwing was mostly studied to explore the early rapid improvement of accuracy, with poor attention on possible adaptive processes occurring later when the rate of improvement is reduced. Here, we tried to demonstrate that the strategy to select angle, speed and height at ball release can be managed during the learning periods following the performance stabilization. To this aim, we used a multivariate linear model with angle, speed and height as predictors of changes in accuracy. Participants performed underarm throws of a tennis ball to hit a target on the floor, 3.42 m away. Two training sessions (S1, S2) and one retention test were executed. Performance accuracy increased over the S1 and stabilized during the S2, with a rate of changes along the throwing axis slower than along the orthogonal axis. However, both the axes contributed to the performance changes over the learning and consolidation time. A stable relationship between the accuracy and the release parameters was observed only during S2, with a good fraction of the performance variance explained by the combination of speed and height. All the variations were maintained during the retention test. Overall, accuracy improvements and reduction in throwing complexity at the ball release followed separate timing over the course of learning and consolidation.

Late Quaternary faulting in the Vallo di Diano basin (southern Apennines, Italy)

NASA Astrophysics Data System (ADS)

Villani, F.; Pierdominici, S.; Cinti, F. R.

2009-12-01

The Vallo di Diano is the largest Quaternary extensional basin in the southern Apennines thrust-belt axis (Italy). This portion of the chain is highly seismic and is currently subject to NE-extension, which triggers large (M> 6) normal-faulting earthquakes along NW-trending faults. The eastern edge of the Vallo di Diano basin is bounded by an extensional fault system featuring three main NW-trending, SW-dipping, right-stepping, ~15-17 km long segments (from north to south: Polla, Atena Lucana-Sala Consilina and Padula faults). Holocene activity has been documented so far only for the Polla segment. We have therefore focused our geomorphological and paleoseismological study on the southern portion of the system, particularly along the ~ 4 km long Atena Lucana-Sala Consilina and Padula faults overlap zone. The latter is characterized by a complex system of coalescent alluvial fans, Middle Pleistocene to Holocene in age. Here we recognized a > 4 km long and 0.5-1.4 km wide set of scarps (ranging in height between 1 m and 2.5 m) affecting Late Pleistocene - Holocene alluvial fans. In the same area, two Late Pleistocene volcanoclastic layers at the top of an alluvial fan exposed in a quarry are affected by ~ 1 m normal displacements. Moreover, a trench excavated across a 2 m high scarp affecting a Holocene fan revealed warping of Late Holocene debris flow deposits, with a total vertical throw of about 0.3 m. We therefore infer the overlap zone of the Atena Lucana-Sala Consilina and Padula faults is a breached relay ramp, generated by hard-linkage of the two fault segments since Late Pleistocene. This ~ 32 km long fault system is active and is capable of generating Mw ≥6.5 earthquakes.

Reservoir characterization and seal integrity of Jemir field in Niger Delta, Nigeria

NASA Astrophysics Data System (ADS)

Adagunodo, Theophilus Aanuoluwa; Sunmonu, Lukman Ayobami; Adabanija, Moruffdeen Adedapo

2017-05-01

Ignoring fault seal and depending solely on reservoir parameters and estimated hydrocarbon contacts can lead to extremely unequal division of reserves especially in oil fields dominated by structural traps where faults play an important role in trapping of hydrocarbons. These faults may be sealing or as conduit to fluid flow. In this study; three-dimensional seismic and well log data has been used to characterize the reservoirs and investigate the seal integrity of fault plane trending NW-SE and dip towards south in Jemir field, Niger-Delta for enhanced oil recovery. The petrophysical and volumetric analysis of the six reservoirs that were mapped as well as structural interpretation of the faults were done both qualitatively and quantitatively. In order to know the sealing potential of individual hydrocarbon bearing sand, horizon-fault intersection was done, volume of shale was determined, thickness of individual bed was estimated, and quality control involving throw analysis was done. Shale Gouge Ratio (SGR) and Hydrocarbon Column Height (HCH) (supportable and structure-supported) were also determined to assess the seal integrity of the faults in Jemir field. The petrophysical analysis indicated the porosity of traps on Jemir field ranged from 0.20 to 0.29 and the volumetric analyses showed that the Stock Tank Original Oil in Place varied between 5.5 and 173.4 Mbbl. The SGR ranged from leaking (<20%) to sealing (>60%) fault plane suggesting poor to moderate sealing. The supportable HCH of Jemir field ranged from 98.3 to 446.2 m while its Structure-supported HCH ranged from 12.1 to 101.7 m. The porosities of Jemir field are good enough for hydrocarbon production as exemplified by its oil reserve estimates. However, improper sealing of the fault plane might enhance hydrocarbon leakage.

Implications of meso- to micro-scale deformation for fault sealing capacity: Insights from the Lenghu5 fold-and-thrust belt, Qaidam Basin, NE Tibetan Plateau

NASA Astrophysics Data System (ADS)

Xie, Liujuan; Pei, Yangwen; Li, Anren; Wu, Kongyou

2018-06-01

As faults can be barriers to or conduits for fluid flow, it is critical to understand fault seal processes and their effects on the sealing capacity of a fault zone. Apart from the stratigraphic juxtaposition between the hanging wall and footwall, the development of fault rocks is of great importance in changing the sealing capacity of a fault zone. Therefore, field-based structural analysis has been employed to identify the meso-scale and micro-scale deformation features and to understand their effects on modifying the porosity of fault rocks. In this study, the Lenghu5 fold-and-thrust belt (northern Qaidam Basin, NE Tibetan Plateau), with well-exposed outcrops, was selected as an example for meso-scale outcrop mapping and SEM (Scanning Electron Microscope) micro-scale structural analysis. The detailed outcrop maps enabled us to link the samples with meso-scale fault architecture. The representative rock samples, collected in both the fault zones and the undeformed hanging walls/footwalls, were studied by SEM micro-structural analysis to identify the deformation features at the micro-scale and evaluate their influences on the fluid flow properties of the fault rocks. Based on the multi-scale structural analyses, the deformation mechanisms accounting for porosity reduction in the fault rocks have been identified, which are clay smearing, phyllosilicate-framework networking and cataclasis. The sealing capacity is highly dependent on the clay content: high concentrations of clay minerals in fault rocks are likely to form continuous clay smears or micro- clay smears between framework silicates, which can significantly decrease the porosity of the fault rocks. However, there is no direct link between the fault rocks and host rocks. Similar stratigraphic juxtapositions can generate fault rocks with very different magnitudes of porosity reduction. The resultant fault rocks can only be predicted only when the fault throw is smaller than the thickness of a faulted bed, in which scenario self-juxtaposition forms between the hanging wall and footwall.

An analysis of gravity data in Area 12, Nevada Test Site

USGS Publications Warehouse

Wahl, R.R.

1969-01-01

The gravity data available from Healey and Miller (1963a) were augmented by new observations along three profiles through two new drill holes in Area 12; UEI2t #1 and UEI2p #1. The data were interpreted to allow evaluation of the geologic structure prior to the planning and excavation of two proposed tunnel complexes, Ul2t and Ul2p. Density values for each of six rock units were determined to allow a two-dimensional analysis of the gravity data along the above-mentioned profiles. The surficial rocks of Quaternary and Tertiary age and the Tertiary volcanic rocks have a weighted average density of 1.86 gm/cc. The density of the caprock at Rainier and Aqueduct Mesas ranges from 2.17 gm/cc at UEI2p #1 to 2.27 gm/cc at UEI2t #1. The Gold Meadows stock and the associated Precambrian quartzite have an arithmetic average density of 2.60 gm/cc for all samples measured. The middle Paleozoic dolomite in Area 12 has an arithmetic average density of 2.75 gm/cc. The clastic rocks of Paleozoic age have an arithmetic average density of 2.60 gm/cc. Interpretation of the residual gravity data indicates a maximum thickness of about 2,800 feet for all Tertiary volcanic rocks. A normal fault striking N. 30 ? E. disrupts the pre-Cenozoic surface at UEI2p #1 and 0.4 mile east of UEI2t #1. The throw within rock of Paleozoic age is about 400-500 feet. Another normal fault that strikes about N. 20 ? E. is located about 1.5 miles east of UEI2p #1. The throw of this fault is at least 1,100 feet in rocks of pre-Cenozoic age. Elevation contours representing the pre-Cenozoic surface in Area 12 show a maximum relief of about 2,000 feet.

Return to Throwing after Shoulder or Elbow Injury.

PubMed

Sgroi, Terrance A; Zajac, John M

2018-03-01

Throwing places high demands on the human body, and specific characteristics are developed over time unique to these athletes. When returning to throw after injury, it is important to follow a criterion-based progression that allows the body to be prepared appropriately for the stresses that throwing will require. There is currently a void in the literature for criteria-based progression that helps these athletes return to the highest level of play. As injury rates continue to rise in baseball, there is increased evidence showing contributions of the core and lower extremity to the baseball pitch. There is also additional data showing pitcher specific characteristics such as range of motion and scapular position in this unique population. The rehab professional should take into account every phase of the pitch starting from balance through ball release when designing a comprehensive return-to-throwing program. Returning an athlete back to a throwing sport can be an overwhelming task. The rehabilitation specialist must have a sound understanding of the throwing motion as well as any biomechanical implications on the body, contributions throughout the kinetic chain, range of motion, and strength characteristics specific to the thrower as well as proper tissue loading principles. It is important that these athletes are not progressed too quickly through their programs and that a criteria-based progression is followed. They should have normalized range of motion, strength, and scapular mechanics, followed by a sound plyometric progression. Once this is achieved, they are advanced to an interval throwing program with increasing distance, effort, and volume which should be tracked for workload, making sure they do not throw more than their body is prepared for.

Recognition of the geologic framework of porphyry deposits on ERTS-1 imagery

NASA Technical Reports Server (NTRS)

Wilson, J. C. (Principal Investigator); Camp, L. W.

1973-01-01

The author has identified the following significant results. Preliminary analysis of a mosaic composing 20 individual ERTS-1 frames that covers most of Nevada and western Utah reveals both new and old structural features. Three separate provinces, the Basin and Range, the southern extension of the Columbia River Plateau volcanics, and the western edge of the Colorado Plateau are easily distinguishable. A west-northwest cross or transverse structural trend, the Las Vegas Shear zone, is present in the region running from the Sierra Nevada to Lake Mead. The Sevier, Hurricane and Grand Wash faults that define the Wasateh-Jerome structural zone, can be traced further on the ERTS-1 imagery than on existing tectonic maps. By use of a stereo viewer on the side-lap coverage of ERTS-1 imagery, it is possible in some instances to determine the direction of sedimentary beds, enabling anticlines and synclines to be mapped. Other geologic features, faults, direction of throw on faults, recent basalt flow contacts with older rhyolitic tuffs, volcanic cones, and subsidences can also be mapped.

Shallow high-resolution geophysical investigation along the western segment of the Victoria Lines Fault (island of Malta)

NASA Astrophysics Data System (ADS)

Villani, Fabio; D'Amico, Sebastiano; Panzera, Francesco; Vassallo, Maurizio; Bozionelos, George; Farrugia, Daniela; Galea, Pauline

2018-01-01

The Victoria Lines Fault (island of Malta) is a >15 km-long and N260°-striking segmented normal fault-system, which is probably inactive since the late Pliocene. In the westernmost part, the Fomm Ir-Rih segment displays comparable geologic throw and escarpment height ( 150-170 m), moreover its hangingwall hosts thin patches of Middle Pleistocene clastic continental deposits (red beds), which are poorly preserved elsewhere. We acquired two seismic transects, by collecting ambient vibration recordings, processed by using horizontal-to-vertical spectral ratios, complemented by one high-resolution 2-D refraction tomography survey crossing this fault where it is locally covered by red beds and recent colluvial deposits. We found a resonance peak at 1.0 Hz in the hangingwall block, whereas clear peaks in the range 5.0-10.0 Hz appear when approaching the subsurface fault, and we relate them to the fractured bedrock within the fault zone. The best-fit tomographic model shows a relatively high-Vp shallow body (Vp 2200-2400 m/s) that we relate to the weathered top of the Miocene Upper Coralline Limestone Fm., bounded on both sides by low-Vp regions (<1400 m/s). The latter are the smeared images of steep fault zones. Tomography further reveals a thick ( 15-20 m) low-Vp (<1000 m/s) zone, which could be a syn-tectonic wedge of colluvial deposits developed in the downthrown block. Surface waves analysis indicates lateral changes of the average shallow shear wave velocity, with Vs 130 m/s within the inferred fault zone, and Vs >230 m/s above the weathered top-bedrock. Our results depict a clear seismic signature of the Victoria Lines Fault, characterized by low seismic velocity and high amplification of ground motion. We hypothesize that, during the Middle Pleistocene, faulting may have affected the basal part of the red beds, so that this part of the investigated complex fault-system may be considered inactive since 0.6 Myr ago.

Paleoseismology and tectonic geomorphology of the Pallatanga fault (Central Ecuador), a major structure of the South-American crust

NASA Astrophysics Data System (ADS)

Baize, Stéphane; Audin, Laurence; Winter, Thierry; Alvarado, Alexandra; Pilatasig Moreno, Luis; Taipe, Mercedes; Reyes, Pedro; Kauffmann, Paul; Yepes, Hugo

2015-05-01

The Pallatanga fault (PF) is a prominent NNE-SSW strike-slip fault crossing Central Ecuador. This structure is suspected to have hosted large earthquakes, including the 1797 Riobamba event which caused severe destructions to buildings and a heavy death toll (more than 12,000 people), as well as widespread secondary effects like landsliding, liquefaction and surface cracking. The scope of this study is to evaluate the seismic history of the fault through a paleoseismological approach. This work also aims at improving the seismotectonic map of this part of the Andes through a new mapping campaign and, finally, aims at improving the seismic hazard assessment. We show that the PF continues to the north of the previously mapped fault portion in the Western Cordillera (Rumipamba-Pallatanga portion) into the Inter-Andean Valley (Riobamba basin). Field evidences of faulting are numerous, ranging from a clear geomorphological signature to fault plane outcrops. Along the western side of the Riobamba basin, the strike-slip component seems predominant along several fault portions, with a typical landscape assemblage (dextral offsets of valleys, fluvial terrace risers and generation of linear pressure ridges). In the core of the inter-Andean valley, the main fault portion exhibits a vertical component along the c. 100 m-high cumulative scarp. The presence of such an active fault bounding the western suburbs of Riobamba drastically increases the seismic risk for this densely inhabited and vulnerable city. To the east (Peltetec Massif, Cordillera Real), the continuation of the Pallatanga fault is suspected, but not definitely proved yet. Based on the analysis of three trenches, we state that the Rumipamba-Pallatanga section of the PF experienced 4 (maybe 5) Holocene to Historical strong events (Mw > 7). The coseismic behavior of the fault is deduced from the occurrence of several colluvial wedges and layers associated with the fault activity and interbedded within the organic black soil sequence. According to a series of 14C datings, we document that these events occurred during the last 6500 years. The clear deformation of the shallowest layer (14C: 1633 AD) is most likely associated with the 1797 Riobamba earthquake. After retrodeforming one of the 3 trenches, we estimate coseismic vertical throws (0.70 to 0.90 m). Because of bad outcrop conditions, we could not determine the horizontal component of slip and we used the slip vector determined in a previous work with a tectonic geomorphology study. Assuming this slip vector, we obtain total coseismic offsets between 3.5 and 4.5 m, indicative of earthquake magnitudes around c. Mw 7.5. The estimated recurrence time intervals range between 1300 and 3000 years, indicating an average slip rate of c. 2.5 mm/a for the Rumipamba-Pallatanga section of the fault.

A successful development of subtle traps: Chihuido de la Sierra Negra, Neuquen Basin

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

Comeron, R.; Valenzuela, M.W.

1996-08-01

Using new traps search concepts in the Chihuido de la Sierra Negra oil field, it was possible to substantially increase production from 4400 bbl/day in 1984 to 125,000 bbl/day in 1995. Oil reserves are located within an 8000 ha area situated on the Chihuido de la Sierra Negra anticlinal flank. Success was achieved by using different techniques for subtle traps detection, namely seismic amplitude mapping, individualization of different production facies and its predictive mapping. This reduced the search and development toward low structural areas which had not been considered before. The production layers are formed by two lower Cretaceous eolianmore » sandstones called the Avile Member and the Troncoso Lower Member, with thicknesses ranging from 5 to 30 meters. 2D seismic made it possible to individualize the thickest sand areas, some of which turned out to be productive. Using 3D seismic, by means of azimuth and dip maps, fractured areas were detected where fault throws range from 5 to 10 meters. In many of these fractured zones, thin igneous intrusives are emplaced forming seals. Such determinations make it possible for different oil-water contacts and static pressures to be delimited. Due to the small fault throws, the different blocks could not be detected by conventional mapping methods. The delineation of the field compartmentalization becomes important in the waterflooding stage as well as for the detection of new traps in surrounding areas. The combination of seismic and stratigraphic methods made it possible to discover and develop Argentina`s main oil field.« less

The contribution of coping related variables and cardiac vagal activity on the performance of a dart throwing task under pressure.

PubMed

Mosley, Emma; Laborde, Sylvain; Kavanagh, Emma

2017-10-01

The aims of this study were 1) to assess the predictive role of coping related variables (CRV) on cardiac vagal activity (derived from heart rate variability), and 2) to investigate the influence of CRV (including cardiac vagal activity) on a dart throwing task under low pressure (LP) and high pressure (HP) conditions. Participants (n=51) completed trait CRV questionnaires: Decision Specific Reinvestment Scale, Movement Specific Reinvestment Scale and Trait Emotional Intelligence Questionnaire. They competed in a dart throwing task under LP and HP conditions. Cardiac vagal activity measurements were taken at resting, task and during recovery for 5min. Self-reported ratings of stress were recorded at three time points via a visual analogue scale. Upon completion of the task, self-report measures of motivation, stress appraisal, attention, perceived pressure and dart throwing experience were completed. Results indicated that resting cardiac vagal activity had no predictors. Task cardiac vagal activity was predicted by resting cardiac vagal activity in both pressure conditions with the addition of a trait CRV in HP. Post task cardiac vagal activity was predicted by resting cardiac vagal activity in both conditions with the addition of a trait CRV in HP. Cardiac vagal reactivity (difference from resting to task) was predicted by a trait CRV in HP conditions. Cardiac vagal recovery (difference from task to post task) was predicted by a state CRV only in LP. Dart throwing task performance was predicted by a combination of both CRV and cardiac vagal activity. The current research suggests that coping related variables and cardiac vagal activity influence dart throwing task performance differently dependent on pressure condition. Copyright © 2017 Elsevier Inc. All rights reserved.

Uranophane at Silver Cliff mine, Lusk, Wyoming

USGS Publications Warehouse

Wilmarth, Verl R.; Johnson, D.H.

1954-01-01

The uranium deposit at the Silver Cliff mine near Lusk, Wyo., consists primarily of uranophane which occurs as fracture fillings and small replacement pockets in faulted and fractured calcareous sandstone of Cambrian (?) age. The country rock in the vicinity of the mine is schist of pre-Cambrian age intruded by pegmatite dikes and is unconformably overlain by almost horizontal sandstone of Cambrian(?) age. The mine is on the southern end of the Lusk Dome, a local structure probably related to the Hartville uplift. In the immediate vicinity of the mine, the dome is cut by the Silver Cliff fault, a north-trending high-angle reverse fault about 1,200 feet in length with a stratigraphic throw of 70 feet. Uranophane, metatorbernite, pitchblende, calcite, native silver, native copper, chalcocite, azurite, malachite, chrysocolla, and cuprite have been deposited in fractured sandstone. The fault was probably mineralized throughout its length, but because of erosion, the mineralized zone is discontinuous. The principal ore body is about 800 feet long. The width and depth of the mineralized zone are not accurately known but are at least 20 feet and 60 feet respectively. The uranium content of material sampled in the mine ranges from 0.001 to 0.23 percent uranium, whereas dump samples range from 0.076 to 3.39 percent uranium.

Effect of upper body plyometric training on physical performance in healthy individuals: A systematic review.

PubMed

Singla, Deepika; Hussain, M Ejaz; Moiz, Jamal Ali

2018-01-01

To determine the impact of upper body plyometric training (UBPT) on physical performance parameters such as strength, ball throwing speed, ball throw distance and power in healthy individuals. PubMed, Scopus, ResearchGate and ERIC databases were searched up to August 2017. Selection of articles was done if they described the outcomes of an upper body plyometric exercise intervention; included measures of strength, ball throwing speed, ball throw distance, or power; included healthy individuals; used a randomized control trial; and had full text available in English language. The exclusion criteria were unpublished research work and clubbing of UBPT with some other type(s) of training apart from routine sports training. PEDro scale was used to rate the quality of studies eligible for this review. Initially 264 records were identified and out of them only 11 articles met the eligibility criteria and were selected (PEDro score = 4 to 6). Though large to very small effects observed in improving ball throwing velocity, ball throwing distance, power and strength of upper limb muscles after UBPT, the results should be implemented with caution. Inconclusive results obtained preclude any strong conclusion regarding the efficacy of UBPT on physical performance in healthy individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experiments on schistosity and slaty cleavage

USGS Publications Warehouse

Becker, George Ferdinand

1904-01-01

Schistosity as a structure is important, and it is a part of the business of geologists to explain its origin. Slaty cleavage has further and greater importance as a possible tectonic feature. Scarcely a great mountain range exists, or has existed, along the course of which belts of slaty rock are not found, the dip of the cleavage usually approaching verticality. Are these slate belts equivalent to minutely distributed step faults of great total throw, or do they indicate compression perpendicular to the cleavage without attendant relative dislocation? Evidently the answer to this question is of first importance in the interpretation of orogenic phenomena.

Geostatistical analysis of fault and joint measurements in Austin Chalk, Superconducting Super Collider Site, Texas

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

Mace, R.E.; Nance, H.S.; Laubach, S.E.

1995-06-01

Faults and joints are conduits for ground-water flow and targets for horizontal drilling in the petroleum industry. Spacing and size distribution are rarely predicted accurately by current structural models or documented adequately by conventional borehole or outcrop samples. Tunnel excavations present opportunities to measure fracture attributes in continuous subsurface exposures. These fracture measurements ran be used to improve structural models, guide interpretation of conventional borehole and outcrop data, and geostatistically quantify spatial and spacing characteristics for comparison to outcrop data or for generating distributions of fracture for numerical flow and transport modeling. Structure maps of over 9 mi of nearlymore » continuous tunnel excavations in Austin Chalk at the Superconducting Super Collider (SSC) site in Ellis County, Texas, provide a unique database of fault and joint populations for geostatistical analysis. Observationally, small faults (<10 ft. throw) occur in clusters or swarms that have as many as 24 faults, fault swarms are as much as 2,000 ft. wide and appear to be on average 1,000 ft. apart, and joints are in swarms spaced 500 to more than 2l,000 ft. apart. Semi-variograms show varying degrees of spatial correlation. These variograms have structured sills that correlate directly to highs and lows in fracture frequency observed in the tunnel. Semi-variograms generated with respect to fracture spacing and number also have structured sills, but tend to not show any near-field correlation. The distribution of fault spacing can be described with a negative exponential, which suggests a random distribution. However, there is clearly some structure and clustering in the spacing data as shown by running average and variograms, which implies that a number of different methods should be utilized to characterize fracture spacing.« less

Normal-faulting slip maxima and stress-drop variability: a geological perspective

USGS Publications Warehouse

Hecker, S.; Dawson, T.E.; Schwartz, D.P.

2010-01-01

We present an empirical estimate of maximum slip in continental normal-faulting earthquakes and present evidence that stress drop in intraplate extensional environments is dependent on fault maturity. A survey of reported slip in historical earthquakes globally and in latest Quaternary paleoearthquakes in the Western Cordillera of the United States indicates maximum vertical displacements as large as 6–6.5 m. A difference in the ratio of maximum-to-mean displacements between data sets of prehistoric and historical earthquakes, together with constraints on bias in estimates of mean paleodisplacement, suggest that applying a correction factor of 1.4±0.3 to the largest observed displacement along a paleorupture may provide a reasonable estimate of the maximum displacement. Adjusting the largest paleodisplacements in our regional data set (~6 m) by a factor of 1.4 yields a possible upper-bound vertical displacement for the Western Cordillera of about 8.4 m, although a smaller correction factor may be more appropriate for the longest ruptures. Because maximum slip is highly localized along strike, if such large displacements occur, they are extremely rare. Static stress drop in surface-rupturing earthquakes in the Western Cordillera, as represented by maximum reported displacement as a fraction of modeled rupture length, appears to be larger on normal faults with low cumulative geologic displacement (<2 km) and larger in regions such as the Rocky Mountains, where immature, low-throw faults are concentrated. This conclusion is consistent with a growing recognition that structural development influences stress drop and indicates that this influence is significant enough to be evident among faults within a single intraplate environment.

Near-surface, marine seismic-reflection data defines potential hydrogeologic confinement bypass in a tertiary carbonate aquifer, southeastern Florida

USGS Publications Warehouse

Cunningham, Kevin J.; Walker, Cameron; Westcott, Richard L.

2012-01-01

Approximately 210 km of near-surface, high-frequency, marine seismic-reflection data were acquired on the southeastern part of the Florida Platform between 2007 and 2011. Many high-resolution, seismic-reflection profiles, interpretable to a depth of about 730 m, were collected on the shallow-marine shelf of southeastern Florida in water as shallow as 1 m. Landward of the present-day shelf-margin slope, these data image middle Eocene to Pleistocene strata and Paleocene to Pleistocene strata on the Miami Terrace. This high-resolution data set provides an opportunity to evaluate geologic structures that cut across confining units of the Paleocene to Oligocene-age carbonate rocks that form the Floridan aquifer system.Seismic profiles image two structural systems, tectonic faults and karst collapse structures, which breach confining beds in the Floridan aquifer system. Both structural systems may serve as pathways for vertical groundwater flow across relatively low-permeability carbonate strata that separate zones of regionally extensive high-permeability rocks in the Floridan aquifer system. The tectonic faults occur as normal and reverse faults, and collapse-related faults have normal throw. The most common fault occurrence delineated on the reflection profiles is associated with karst collapse structures. These high-frequency seismic data are providing high quality structural analogs to unprecedented depths on the southeastern Florida Platform. The analogs can be used for assessment of confinement of other carbonate aquifers and the sealing potential of deeper carbonate rocks associated with reservoirs around the world.

Geomorphic and Structural Evidence for Rolling Hinge Style Deformation in the Footwall of an Active Low Angle Normal Fault, Mai'iu Fault, Woodlark Rift, SE Papua New Guinea

NASA Astrophysics Data System (ADS)

Mizera, M.; Little, T.; Norton, K. P.; Webber, S.; Ellis, S. M.; Oesterle, J.

2016-12-01

While shown to operate in oceanic crust, rolling hinge style deformation remains a debated process in metamorpic core complexes (MCCs) in the continents. The model predicts that unloading and isostatic uplift during slip causes a progressive back-tilting in the upper crust of a normal fault that is more steeply dipping at depth. The Mai'iu Fault in the Woodlark Rift, SE Papua New Guinea, is one of the best-exposed and fastest slipping (probably >7 mm/yr) active low-angle normal faults (LANFs) on Earth. We analysed structural field data from this fault's exhumed slip surface and footwall, together with geomorphic data interpreted from aerial photographs and GeoSAR-derived digital elevation models (gridded at 5-30 m spacing), to evaluate deformational processes affecting the rapidly exhuming, domal-shaped detachment fault. The exhumed fault surface emerges from the ground at the rangefront near sea level with a northward dip of 21°. Up-dip, it is well-preserved, smooth and corrugated, with some fault remnants extending at least 29 km in the slip direction. The surface flattens over the crest of the dome, beyond where it dips S at up to 15°. Windgaps perched on the crestal main divide of the dome, indicate both up-dip tectonic advection and progressive back-tilting of the exhuming fault surface. We infer that slip on a serial array of m-to-km scale up-to-the-north, steeply S-dipping ( 75°) antithetic-sense normal faults accommodated some of the exhumation-related, inelastic bending of the footwall. These geomorphically well expressed faults strike parallel to the main Mai'iu fault at 110.9±5°, have a mean cross-strike spacing of 1520 m, and slip with a consistent up-to-the-north sense of throw ranging from <5 m to 120 m. Apparently the Mai'iu Fault was able to continue slipping despite having to negotiate this added fault-roughness. We interpret the antithetic faulting to result from bending stresses, and to provide the first clear examples of rolling hinge-style accommodation structures on a continental MCC.

In Search of the Loci for Sex Differences in Throwing: The Effects of Physical Size and Differential Recruitment Rates on High Levels of Dart Performance

ERIC Educational Resources Information Center

Duffy, Linda J.; Ericsson, K. Anders; Baluch, Bahman

2007-01-01

Contemporary accounts of sex differences in perceptual-motor performance differ in their emphasis on nature and nurture. Study 1 examined the effect of extensive training on one of the largest sex differences, namely accuracy in dart throwing, and found that physical differences in height and reach could not explain sex differences in…

The 2016-2017 central Italy coseismic surface ruptures and their meaning with respect to foreseen active fault systems segmentation

NASA Astrophysics Data System (ADS)

De Martini, P. M.; Pucci, S.; Villani, F.; Civico, R.; Del Rio, L.; Cinti, F. R.; Pantosti, D.

2017-12-01

In 2016-2017 a series of moderate to large normal faulting earthquakes struck central Italy producing severe damage in many towns including Amatrice, Norcia and Visso and resulting in 299 casualties and >20,000 homeless. The complex seismic sequence depicts a multiple activation of the Mt. Vettore-Mt. Bove (VBFS) and the Laga Mts. fault systems, which were considered in literature as independent segments characterizing a recent seismic gap in the region comprised between two modern seismic sequences: the 1997-1998 Colfiorito and the 2009 L'Aquila. We mapped in detail the coseismic surface ruptures following three mainshocks (Mw 6.0 on 24th August, Mw 5.9 and Mw 6.5 on 26th and 30th October, 2016, respectively). Primary surface ruptures were observed and recorded for a total length of 5.2 km, ≅10 km and ≅25 km, respectively, along closely-spaced, parallel or subparallel, overlapping or step-like synthetic and antithetic fault splays of the activated fault systems, in some cases rupturing repeatedly the same location. Some coseismic ruptures were mapped also along the Norcia Fault System, paralleling the VBFS about 10 km westward. We recorded geometric and kinematic characteristics of the normal faulting ruptures with an unprecedented detail thanks to almost 11,000 oblique photographs taken from helicopter flights soon after the mainshocks, verified and integrated with field data (more than 7000 measurements). We analyze the along-strike coseismic slip and slip vectors distribution to be observed in the context of the geomorphic expression of the disrupted slopes and their depositional and erosive processes. Moreover, we constructed 1:10.000 scale geologic cross-sections based on updated maps, and we reconstructed the net offset distribution of the activated fault system to be compared with the morphologic throws and to test a cause-effect relationship between faulting and first-order landforms. We provide a reconstruction of the 2016 coseismic rupture pattern as representative of the VBFS behavior, a discussion on the fault system boundaries persistence, and on the significance of the repeated surface faulting at same location.

Segmentation of the Cascadia Forearc in Southwestern Washington—Evidence from New Potential-Field Data

NASA Astrophysics Data System (ADS)

Blakely, R. J.; Wells, R. E.; Sherrod, B. L.; Brocher, T. M.

2016-12-01

Newly acquired potential-field data, geologic mapping, and recorded seismicity indicate that the Cascadia subduction zone is segmented in southwestern Washington by a left-stepping, possibly active crustal structure spanning nearly the entire onshore portion of the forearc. The east-striking, southward verging Doty thrust fault is an important part of this trans-forearc structure. As mapped, the eastern end of the 50-km-long Doty fault connects with the northwestern termination of ongoing seismicity on the north-northwest-striking Mt. St. Helens seismic zone (MSHSZ), suggesting that the Doty fault and MSHSZ may be kinematically linked. Westward, the mapped Doty fault terminates at and may link to mapped faults striking northwestward to 35 km north of Grays Harbor, a total northwest distance of 85 km. A newly acquired aeromagnetic survey over the Doty fault and MSHSZ, and existing gravity data, emphasize Crescent Formation and other Eocene volcanic rocks in the hanging wall of the Doty fault with up to 4 km of vertical throw. Most MSHSZ epicenters fall within a broad (5- to 10-km wide) magnetic low extending 50 km north-northwestward from Mt. St Helens. The magnetic low skirts around the western margin of the Miocene-age Spirit Lake pluton, but otherwise is not obviously associated with topography or mapped geology. We suggest that dextral slip on the MSHSZ is distributed across a broad, northwest-striking area that includes the magnetic low and is transferred to compressional slip on the Doty fault. The Doty fault demarcates a clear north-to-south decrease in the density of episodic tremor, suggesting that the thrust fault may intersect or modulate over-pressured fluids generated above the slab (Wells et al., in review). The Doty fault, MSHSZ, and neighboring structures are consistent with a dextral shear couple (Wells and Coe, 1985) and consequent clockwise crustal rotation extending across the entire landward portion of the Cascadia forearc, from the Pacific Coast to the Cascadia arc and from Grays Harbor to the Portland basin in northwestern Oregon.

Timescale dependent deformation of orogenic belts?

NASA Astrophysics Data System (ADS)

Hoth, S.; Friedrich, A. M.; Vietor, T.; Hoffmann-Rothe, A.; Kukowski, N.; Oncken, O.

2004-12-01

The principle aim to link geodetic, paleoseismologic and geologic estimates of fault slip is to extrapolate the respective rates from one timescale to the other to finally predict the recurrence interval of large earthquakes, which threat human habitats. This approach however, is based on two often implicitly made assumptions: a uniform slip distribution through time and space and no changes of the boundary conditions during the time interval of interest. Both assumptions are often hard to verify. A recent study, which analysed an exceptionally complete record of seismic slip for the Wasatch and related faults (Basin and Range province), ranging from 10 yr to 10 Myr suggests that such a link between geodetic and geologic rates might not exist, i.e., that our records of fault displacement may depend on the timescale over which they were measured. This view derives support from results of scaled 2D sandbox experiments, as well as numerical simulations with distinct elements, both of which investigated the effect of boundary conditions such as flexure, mechanic stratigraphy and erosion on the spatio-temporal distribution of deformation within bivergent wedges. We identified three types of processes based on their distinct spatio-temporal distribution of deformation. First, incremental strain and local strain rates are very short-lived are broadly distributed within the bivergent wedge and no temporal pattern could be established. Second, footwall shortcuts and the re-activation of either internal thrusts or of the retro shear-zone are irregularly distributed in time and are thus not predictable either, but last for a longer time interval. Third, the stepwise initiation and propagation of the deformation front is very regular in time, since it depends on the thickness of the incoming layer and on its internal and basal material properties. We consider the propagation of the deformation front as an internal clock of a thrust belt, which is therefore predictable. A deformation front advance cycle requires the longest timescale. Thus, despite known and constant boundary conditions during the simulations, we found only one regular temporal pattern of deformation in a steady active bivergent-wedge. We therefore propose that the structural inventory of an orogenic belt is hierarchically ordered with respect to accumulated slip, in analogy to the discharge pattern in a drainage network. The deformation front would have the highest, a branching splay the lowest order. Since kinematic boundary conditions control deformation front advance, its timing and the related maximum magnitude of finite strain, i.e. throw on the frontal thrust are predictable. However, the number of controlling factors, such as the degree of strain softening, the orientation of faults or fluid flow and resulting cementation of faults, responsible for the reactivation of faults increases with increasing distance from the deformation front. Since it is rarely possible to determine the complete network of forces within a wedge, the reactivation of lower order structures is not predictable in time and space. Two implications for field studies may emerge: A change of the propagation of deformation can only be determined, if at least two accretion cycles are sampled. The link between geodetic, paleoseismologic and geologic fault slip estimates can only be successfully derived if the position of the investigated fault within the hierarchical order has not changed over the time interval of interest.

Syntectonic Deposition of Plio-Quaternary Sediments in the Santa Rosalia Basin of Baja California Sur, Mexico

NASA Astrophysics Data System (ADS)

Michels, A.; Johnson, L.; Niemi, T. M.

2017-12-01

Plio-Quaternary sediments of the Tirabuzón, Infierno, and Santa Rosalía formations record syntectonic deposition in the Santa Rosalía basin—an oblique-rift-margin basin along the Gulf of California in Baja California Sur, Mexico. These deposits unconformably overlie the upper Miocene, Cu-Zn-Co-Mn-rich Boleo Formation. The Mesa Soledad outcrops, exposed on the Minera Boleo mine property, show interfingering of marine and terrestrial deposits of the three formations along the inland margin of the basin in an area that has not previously been studied. Faults that cut the Pliocene section of the mesa are mostly steeply-dipping, NW- and NE-striking faults with normal displacement determined from stratigraphic offset and steep plunge in striations. Two stratigraphic sections were measured on either side of one of these high-angle, NW-striking fault that has a normal throw of 26 m. Our analyses of sediment grain size, fossil assemblages, and sedimentary petrography indicate a mismatch of the stratigraphic units across the fault and suggest a component of strike slip. North of the fault, poorly-sorted, well-rounded, fluvial gravels from the Pliocene-aged, Tirabuzón Formation unconformably underlie fossiliferous marine deposits from the late-Pliocene to Pleistocene? -aged Infierno Formation. South of the fault, marine deposits of the Tirabuzón Formation grade upward into imbricated, clast-supported beach gravel, and finally into non-marine conglomerates. The absence of the Infierno Formation on the southern side of the fault suggests the deposits were either eroded unevenly due to uplift or laterally displaced by strike-slip movement. Fossiliferous sandstones and conglomerates of the Santa Rosalía Formation unconformably cap the entire outcrop and show no displacement from faulting. The Santa Rosalía Formation is overlain by the 1.4 Ma La Reforma ignimbrite (Schmidt 2006), indicating that the style of deformation of the basin changed at approximately this time.

Significant role of structural fractures in Ren-Qiu buried-block oil field, eastern China

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

Fei, Q.; Xie-Pei, W.

1983-03-01

Ren-qui oil field is in a buried block of Sinian (upper Proterozoic) rocks located in the Ji-zhong depression of the western Bohai Bay basin in eastern China. The main reservoir consists of Sinian dolomite rocks. It is a fault block with a large growth fault on the west side which trends north-northeast with throws of up to 1 km (0.6 mi) or more. The source rocks for the oil are Paleogene age and overlie the Sinian dolomite rocks. The structural fractures are the main factor forming the reservoir of the buried-block oil field. Three structural lines, trending northeast, north-northeast, andmore » northwest, form the regional netted fracture system. The north-northeast growth fault controlled the structural development of the buried block. The block was raised and eroded before the Tertiary sediments were deposited. In the Eocene Epoch, the Ji-zhong depression subsided, but the deposition, faulting, and related uplift of the block happened synchronously as the block was gradually submerged. At the same time, several horizontal and vertical karst zones were formed by the karst water along the netted structural fractures. The Eocene oil source rocks lapped onto the block and so the buried block, with many developed karst fractures, was surrounded by a great thickness of source rocks. As the growth fault developed, the height of the block was increased from 400 m (1300 ft) before the Oligocene to 1300 m (4250 ft) after. As the petroleum was generated, it migrated immediately into the karst fractures of the buried block along the growth fault. The karst-fractured block reservoir has an 800-m (2600-ft) high oil-bearing closure and good connections developed between the karst fractures.« less

Changes in Muscle Architecture, Explosive Ability, and Track and Field Throwing Performance Throughout a Competitive Season and After a Taper.

PubMed

Bazyler, Caleb D; Mizuguchi, Satoshi; Harrison, Alex P; Sato, Kimitake; Kavanaugh, Ashley A; DeWeese, Brad H; Stone, Michael H

2017-10-01

The purpose of this study was to examine the effects of an overreach and taper on measures of muscle architecture, jumping, and throwing performance in Division I collegiate throwers preparing for conference championships. Six collegiate track and field throwers (3 hammer, 2 discus, 1 javelin) trained for 12 weeks using a block-periodization model culminating with a 1-week overreach followed by a 3-week taper (ORT). Session rating of perceived exertion training load (RPETL) and strength training volume-load times bar displacement (VLd) were recorded weekly. Athletes were tested pre-ORT and post-ORT on measures of vastus lateralis architecture, unloaded and loaded squat and countermovement jump performance, underhand and overhead throwing performance, and competition throwing performance. There was a statistical reduction in weight training VLd/session (d = 1.21, p ≤ 0.05) and RPETL/session (d = 0.9, p ≤ 0.05) between the in-season and ORT training phases. Five of 6 athletes improved overhead throw and competition throwing performance after the ORT (d = 0.50, p ≤ 0.05). Vastus lateralis muscle thickness statistically increased after the in-season training phase (d = 0.28, p ≤ 0.05) but did not change after the ORT. Unloaded countermovement jump peak force and relative peak power improved significantly after the ORT (d = 0.59, p ≤ 0.05, d = 0.31, p ≤ 0.05, respectively). These findings demonstrate that an overreaching week followed by a 3-week taper is an effective means of improving explosive ability and throwing performance in collegiate track and field throwers despite the absence of detectable changes in muscle architecture.

Geophysical examination of coal deposits

NASA Astrophysics Data System (ADS)

Jackson, L. J.

1981-04-01

Geophysical techniques for the solution of mining problems and as an aid to mine planning are reviewed. Techniques of geophysical borehole logging are discussed. The responses of the coal seams to logging tools are easily recognized on the logging records. Cores for laboratory analysis are cut from selected sections of the borehole. In addition, information about the density and chemical composition of the coal may be obtained. Surface seismic reflection surveys using two dimensional arrays of seismic sources and detectors detect faults with throws as small as 3 m depths of 800 m. In geologically disturbed areas, good results have been obtained from three dimensional surveys. Smaller faults as far as 500 m in advance of the working face may be detected using in seam seismic surveying conducted from a roadway or working face. Small disturbances are detected by pulse radar and continuous wave electromagnetic methods either from within boreholes or from underground. Other geophysical techniques which explicit the electrical, magnetic, gravitational, and geothermal properties of rocks are described.

Identifying Conventionally Sub-Seismic Faults in Polygonal Fault Systems

NASA Astrophysics Data System (ADS)

Fry, C.; Dix, J.

2017-12-01

Polygonal Fault Systems (PFS) are prevalent in hydrocarbon basins globally and represent potential fluid pathways. However the characterization of these pathways is subject to the limitations of conventional 3D seismic imaging; only capable of resolving features on a decametre scale horizontally and metres scale vertically. While outcrop and core examples can identify smaller features, they are limited by the extent of the exposures. The disparity between these scales can allow for smaller faults to be lost in a resolution gap which could mean potential pathways are left unseen. Here the focus is upon PFS from within the London Clay, a common bedrock that is tunnelled into and bears construction foundations for much of London. It is a continuation of the Ieper Clay where PFS were first identified and is found to approach the seafloor within the Outer Thames Estuary. This allows for the direct analysis of PFS surface expressions, via the use of high resolution 1m bathymetric imaging in combination with high resolution seismic imaging. Through use of these datasets surface expressions of over 1500 faults within the London Clay have been identified, with the smallest fault measuring 12m and the largest at 612m in length. The displacements over these faults established from both bathymetric and seismic imaging ranges from 30cm to a couple of metres, scales that would typically be sub-seismic for conventional basin seismic imaging. The orientations and dimensions of the faults within this network have been directly compared to 3D seismic data of the Ieper Clay from the offshore Dutch sector where it exists approximately 1km below the seafloor. These have typical PFS attributes with lengths of hundreds of metres to kilometres and throws of tens of metres, a magnitude larger than those identified in the Outer Thames Estuary. The similar orientations and polygonal patterns within both locations indicates that the smaller faults exist within typical PFS structure but are sub-seismic in conventional imaging techniques. These unseen faults could create additional unseen pathways that impact construction in London via water ingress and influence fluid migration within hydrocarbon basins.

Acute effect of stretching modalities and time-pressure on accuracy and consistency of throwing darts among 12- and 13-year-old schoolboys.

PubMed

Frikha, Mohamed; Chaâri, Nesrine; Derbel, Mohammad S; Elghoul, Yousri; Zinkovsky, Anatoly V; Chamari, Karim

2017-09-01

The present study addressed the lack of data on the effect of different types of stretching on selected measures of throwing accuracy. We hypothesized that the stretching procedures, within pre-exercise warm-up, could affect the accuracy and the consistency in throwing darts performances under different stress conditions. Eighteen right-handed schoolboys (13.1±0.4 years, 166±0.1 cm and 54.5±9 kg; mean±SD) completed the Darts Throwing Accuracy Test in free (FDT) and in time-pressure (TPDT) conditions, either after static (SS), dynamic (DS), ballistic (BS) or no-stretching (NS) protocols, on nonconsecutive days and in a counter-balanced randomized order. After performing 5 minutes of light standardized jogging and one of the three stretching protocols for 10 minutes, each participant completed the FDT and TPDT tests. Mean scores, missed darts and variability of scores, were recorded and analyzed using a two-way ANOVA with repeated measures. Heart rate (HR), ratings of perceived exertion (RPE) and the task difficulty perception (DP), were recorded through each experimental session. There was no effect of the stretching procedures on accuracy in FDT. However, in the TPDT condition, better performances were recorded after NS and SS compared to DS and BS. The accuracy performances decreased in TPDT by 9.6% after NS (P<0.01); 15.3% after DS (P<0.001) and 11.8% after BS (P<0.001); but not after SS (P<0.05). Static stretching helped reducing the adverse effects of time-pressure on darts throwing performance. Consequently, static exercises are recommended before practicing activities requiring both upper limbs speed and accuracy.

The Throws: Contemporary Theory, Technique and Training.

ERIC Educational Resources Information Center

Wilt, Fred, Ed.

This compilation of articles covers the subject of four throwing events--shot put, discus throw, hammer throw, and javelin throw. The history of the art and science of throwing is traced from ancient to modern times in the introduction. Theories on training and techniques of throwing are presented in essays contributed by coaches from the United…

Does the junior IAAF athletic world championship represent a springboard for the success in the throwing events? A retrospective study.

PubMed

Piacentini, M F; Comotto, S; Guerriero, A; Bonato, M; Vernillo, G; La Torre, A

2014-08-01

The aim of the present study was to analyze how many finalists of the IAAF World Junior Championships (WJC) in the throwing events were present in the senior IAAF ranking at the end of 2012. The results of the 8 male and the 8 female finalists of all throwing events of the last 5 editions of the WJC from the 2002 edition were gathered. We analyzed how many athletes were missing from the IAAF ranking in 2012. For those athletes that did not drop out we monitored their progression in performance comparing their WJC and their 2012 performance. Moreover, we evaluated if the relative age effects (RAE) influenced drop out rate. Drop out rate was 58% in 2002, 59% in 2004, 39% in 2006, and 28% in 2008 and in 2010. The female javelin throwers showed the highest drop out rate (100%) in 2002, while the female hammer throwers showed the lowest drop out rate (0%) in 2008. Performance decreased for all male shot putters, discus and hammer throwers (P<0.001). For females and for male javelin throwers, performance increased (P<0.001). RAEs showed no significant influence on drop out rate Even if 8 of the finalists won a medal at the Olympic Games or at the World Championships, it is still not clear if participation at the WJC is a prerequisite to success at a senior level, given the elevated drop out rate observed in the present study.

Elasto-plastic deformation and plate weakening due to normal faulting in the subducting plate along the Mariana Trench

NASA Astrophysics Data System (ADS)

Zhou, Z.; Lin, J.

2017-12-01

We investigated variations in the elasto-plastic deformation of the subducting plate along the Mariana Trench through an analysis of flexural bending, normal fault characteristics, and geodynamic modeling. It was observed that most of the normal faults were initiated along the outer-rise region and grew toward the trench axis with strikes that are mostly subparallel to the local trend of the trench axis. The average trench relief is more than 5 km in the southern region while only about 2 km in the northern and central regions. Fault throws were measured to be significantly greater in the southern region (maximum 320 m) than the northern and central regions (maximum 200 m). The subducting plate was modeled as an elasto-plastic slab subjected to tectonic loading along the trench axis. The "apparent" slab-pull dip angle of the subducting plate, calculated from the ratio of the inverted vertical loading versus horizontal tensional force, was significantly larger in the southern region (51-64°) than in the northern (22-35°) and central (20-34°) regions, which is consistent with the seismologically determined dip angle within the shallow part of the subducting slab. This result suggests that the differences in the plate flexure and normal faulting characteristics along the Mariana Trench might be influenced, at least in part, by significant variations in the dip angle within the shallow part of the subducting plate. Normal faults were modeled to penetrate to a maximum depth of 15, 14, and 25 km in the upper mantle for the northern, central, and southern regions, respectively, which is consistent with the depths of available relocated normal faulting earthquakes in the central region. We calculated that the average reduction of the effective elastic plate thickness Te due to normal faulting is 31% in the southern region, which is almost twice that in both the northern and central regions ( 16%). Furthermore, model results revealed that the stress reduction associated with individual normal faults could also decrease Te locally.

From Target Selection to Post-Stimulation Analysis: Example of an Unconventional Faulted Reservoir

NASA Astrophysics Data System (ADS)

LeCalvez, J. H.; Williams, M.; Xu, W.; Stokes, J.; Moros, H.; Maxwell, S. C.; Conners, S.

2011-12-01

As the global balance of supply and demand forces the hydrocarbon industry toward unconventional resources, technology- and economics-driven shale oil and gas production is gaining momentum throughout many basins worldwide. Production from such unconventional plays is facilitated by massive hydraulic fracturing treatments aimed at increasing permeability and reactivating natural fractures. Large-scale faulting and fracturing partly control stress distribution, hence stimulation-derived hydraulically-induced fracture systems development. Therefore, careful integrated approaches to target selection, treatment staging, and stimulation methods need to be used to economically maximize ultimate hydrocarbon recovery. We present a case study of a multistage, multilateral stimulation project in the Fort Worth Basin, Texas. Wells had to be drilled within city limits in a commercially developing building area. Well locations and trajectories were determined in and around large-scale faults using 3D surface seismic with throws varying from seven to thirty meters. As a result, three horizontal wells were drilled in the Lower Barnett Shale section, 150 m apart with the central well landed about 25 m shallower than the outside laterals. Surface seismic indicates that the surface locations are on top of a major fault complex with the lateral sections drilling away from the major fault system and through a smaller fault. Modeling of the borehole-based microseismic monitoring options led to the selection of an optimum set of configurations given the operational restrictions faced: monitoring would mainly take place using a horizontal array to be tractored downhole and moved according to the well and stage to be monitored. Wells were completed using a perf-and-plug approach allowing for each stimulation stage to obtain a precise orientation of the various three-component accelerometers of the monitoring array as well as the calibration of the velocity model used to process the microseismic data acquired. Real-time microseismic monitoring allowed (i) to avoid the water-bearing formation below the zone of interest, (ii) to bypass the faulted zone, and (iii) to modify as needed the perforation and stimulation plans. Completion led to an initial gas production of over 3 MMCF/day each. Early decline rates confirm successful completion in avoiding the faulted areas. Initial observations of the slickwater fracturing stimulation treatments for these three wells using an integrated approach involving mechanical modelling calibrated using microseismic data indicate that (i) a long bi-wing-like fracture system initiated prior to being followed by a complex fracture network; thus, explaining the fact that some events are mapped relatively far away from the injection site, (ii) proppant generally settled down in the near wellbore area during the fracture network development due to rapid decrease of fluid flow velocity away from the injection side. Initial b-value results seem to indicate that the target reservoir is naturally fractured and that the influence of a large fault system in the vicinity of the treated zone could be asserted.

Development of Overarm Throwing Technique Reflects Throwing Ability during Childhood

PubMed Central

KASUYAMA, Tatsuya; MUTOU, Ikuo; SASAMOTO, Hitoshi

2016-01-01

Background: It is important to acquire fundamental movement skills during childhood. Throwing is a representative manipulative skill required for various intrinsic factors. However, the relationship between intrinsic factors and throwing ability in childhood is unclear. The purpose of this study was to investigate intrinsic factors related to the ball throwing distance of Japanese elementary school children. Methods: Japanese elementary school children from grades 1-6 (aged 6-12 years; n=112) participated in this study. The main outcome was throwing ability, which was measured as the ball throwing distance. We measured five general anthropometric parameters, seven physical fitness parameters, and the Roberton's developmental sequence for all subjects. The relationships between the throwing ability and the 13 parameters were analysed. Results: The Roberton's developmental sequence was the best predictor of ball throwing distance (r=0.80, p≤0.01). The best multiple regression model, which included sex, handgrip strength, shuttle run test, and the Roberton's developmental sequence, accounted for 81% of the total variance. Conclusions: The development of correct throwing technique reflects throwing abilities in childhood. In addition to the throwing sequence, enhancement of grip strength and aerobic capacity are also required for children's throwing ability. PMID:28289578

Oblique reactivation of lithosphere-scale lineaments controls rift physiography - the upper-crustal expression of the Sorgenfrei-Tornquist Zone, offshore southern Norway

NASA Astrophysics Data System (ADS)

Phillips, Thomas B.; Jackson, Christopher A.-L.; Bell, Rebecca E.; Duffy, Oliver B.

2018-04-01

Pre-existing structures within sub-crustal lithosphere may localise stresses during subsequent tectonic events, resulting in complex fault systems at upper-crustal levels. As these sub-crustal structures are difficult to resolve at great depths, the evolution of kinematically and perhaps geometrically linked upper-crustal fault populations can offer insights into their deformation history, including when and how they reactivate and accommodate stresses during later tectonic events. In this study, we use borehole-constrained 2-D and 3-D seismic reflection data to investigate the structural development of the Farsund Basin, offshore southern Norway. We use throw-length (T-x) analysis and fault displacement backstripping techniques to determine the geometric and kinematic evolution of N-S- and E-W-striking upper-crustal fault populations during the multiphase evolution of the Farsund Basin. N-S-striking faults were active during the Triassic, prior to a period of sinistral strike-slip activity along E-W-striking faults during the Early Jurassic, which represented a hitherto undocumented phase of activity in this area. These E-W-striking upper-crustal faults are later obliquely reactivated under a dextral stress regime during the Early Cretaceous, with new faults also propagating away from pre-existing ones, representing a switch to a predominantly dextral sense of motion. The E-W faults within the Farsund Basin are interpreted to extend through the crust to the Moho and link with the Sorgenfrei-Tornquist Zone, a lithosphere-scale lineament, identified within the sub-crustal lithosphere, that extends > 1000 km across central Europe. Based on this geometric linkage, we infer that the E-W-striking faults represent the upper-crustal component of the Sorgenfrei-Tornquist Zone and that the Sorgenfrei-Tornquist Zone represents a long-lived lithosphere-scale lineament that is periodically reactivated throughout its protracted geological history. The upper-crustal component of the lineament is reactivated in a range of tectonic styles, including both sinistral and dextral strike-slip motions, with the geometry and kinematics of these faults often inconsistent with what may otherwise be inferred from regional tectonics alone. Understanding these different styles of reactivation not only allows us to better understand the influence of sub-crustal lithospheric structure on rifting but also offers insights into the prevailing stress field during regional tectonic events.

Performance and Kinematics of Various Throwing Techniques in Team-Handball

PubMed Central

Wagner, Herbert; Pfusterschmied, Jürgen; von Duvillard, Serge P.; Müller, Erich

2011-01-01

In team-handball competition, the players utilize various throwing techniques that differ in the lower body movements (with and without run-up or jump). These different lower body movements influence changes in the upper body movements and thus also affect the performance. A comprehensive analysis of 3D-kinematics of team-handball throws that may explain these differences in performance is lacking. Consequently, the purpose of this study was (1) to compare performance (ball velocity and throwing accuracy) between the jump throw, standing throw with and without run-up, and the pivot throw; (2) to calculate the influence of kinematic parameters to ball velocity; and (3) to determine if these four throwing techniques differ significantly in kinematics. Three-dimensional kinematic data (angles, angular velocities and their timing, ball velocity and velocity of the center of mass) of 14 elite team-handball players were measured using an 8 camera Vicon MX13 motion capture system (Vicon, Oxford, UK), at 250 Hz. Significant difference was found between the four throwing techniques for ball velocity (p < 0. 001), maximal velocity of the center of mass in goal-directed movement (p < 0.001), and 15 additional kinematic variables (p < 0.003). Ball velocity was significant impacted by the run-up and the pelvis and trunk movements. Depending on floor contact (standing vs. jump throws), elite players in the study used two different strategies (lead leg braces the body vs. opposed leg movements during flight) to accelerate the pelvis and trunk to yield differences in ball velocity. However, these players were able to utilize the throwing arm similarly in all four throwing techniques. Key points Elite team-handball players achieved the greatest ball velocity in the standing throw with run-up (100%), followed by the standing throw without run-up (93%), jump throw (92%) and pivot throw (85%). Depending on the floor contact (standing vs. jump throws) the elite players of the study used two different strategies (lead leg braces the body vs. opposed leg movements during flight) to accelerate the pelvis and trunk that caused differences in ball velocity. Elite team-handball players were able to utilize the throwing arm similarly in all four throwing techniques. PMID:24149298

Effect of a 6-Week Weighted Baseball Throwing Program on Pitch Velocity, Pitching Arm Biomechanics, Passive Range of Motion, and Injury Rates.

PubMed

Reinold, Michael M; Macrina, Leonard C; Fleisig, Glenn S; Aune, Kyle; Andrews, James R

Emphasis on enhancing baseball pitch velocity has become popular, especially through weighted-ball throwing. However, little is known about the physical effects or safety of these programs. The purpose of this study was to examine the effects of training with weighted baseballs on pitch velocity, passive range of motion (PROM), muscle strength, elbow torque, and injury rates. A 6-week weighted ball training program would result in a change in pitching biomechanical and physical characteristics. Randomized controlled trial. Level 1. During the baseball offseason, 38 healthy baseball pitchers were randomized into a control group and an experimental group. Pitch velocity, shoulder and elbow PROM, shoulder strength, elbow varus torque, and shoulder internal rotation velocity were measured in both groups. The experimental group then performed a 6-week weighted ball throwing program 3 times per week using balls ranging from 2 to 32 ounces while the control group only used a 5-ounce regulation baseball. Both groups performed a strength training program. Measurements were then repeated after the 6-week period. Injuries were tracked over the 6-week training program and the subsequent baseball season. The effect of training with a weighted ball program was assessed using 2-way repeated-measures analysis of variance at an a priori significance level of P < 0.05. Mean age, height, mass, and pretesting throwing velocity were 15.3 ± 1.2 years (range, 13-18 years), 1.73 ± 0.28 m, 68.3 ± 11 kg, and 30.3 ± 0.7 m/s, respectively. Pitch velocity showed a statistically significant increase (3.3%) in the experimental group ( P < 0.001). There was a statistically significant increase of 4.3° of shoulder external rotation in the experimental group. The overall injury rate was 24% in the experimental group. Four participants in the experimental group suffered elbow injuries, 2 during the training program and 2 in the season after training. No pitchers in the control group were injured at any time during the study. Performing a 6-week weighted ball throwing program increased pitch velocity. However, the program resulted in increased shoulder external rotation PROM and increased injury rate. Although weighted-ball training may increase pitch velocity, caution is warranted because of the notable increase in injuries and physical changes observed in this cohort.

Kinematic comparison of team handball throwing with two different arm positions.

PubMed

Wagner, Herbert; Buchecker, Michael; von Duvillard, Serge P; Müller, Erich

2010-12-01

The aims of the present study were: (1) to compare the differences in the ball release speed and throwing accuracy between the ABOVE and SIDE throw; (2) to analyze kinematic differences of these two throwing techniques; and (3) to give practical applications to team handball coaches and players. Ball release speed, throwing accuracy, and kinematics were measured via the Vicon MX 13 (Vicon Peak, Oxford, UK) from 12 male elite right-handed team handball players. Results of our study suggest that the two throwing techniques differ significantly (P < .0073) in the angles and/or angular velocities of the trunk (flexion, left tilt and rotation) and shoulder (flexion and abduction) of the throwing arm that result in a significantly different ball release speed (1.4 ± 0.8 m/s; P < .001) and that throwing accuracy was not significantly different. Our results indicated that the different position of the hand at ball release of the ABOVE and SIDE throws is primarily caused by different trunk flexion and tilt angles that lead to differences in ball release speed but not in throwing accuracy, and that the participants try to move their throwing arm similarly in both throwing techniques.

Partitioning of deformation along a reactivated rifted margin: example of the northern Ligurian margin.

NASA Astrophysics Data System (ADS)

Sage, Françoise; Beslier, Marie-Odile; Gaullier, Virginie; Larroque, Christophe; Dessa, Jean-Xavier; Mercier de Lepinay, Bernard; Corradi, Nicola; Migeon, Sébastien; Katz, Hélène; Ruiz Constan, Ana

2013-04-01

The northern Ligurian margin, of Oligo-Miocene age, is currently undergoing compression related to microplate motions and/or to gravity spreading of the Alpine chain located immediately north of it. Active thrust faults and folds have previously been identified below the margin, together with a global uplift of the continental edge, since at least the Messinian. The seismicity that goes with the present-day margin contraction (e.g. Mw 6.9, 1887/02/23) extends to the axis of the adjacent oceanic basin (e.g. ML 6.0, 1963/07/19; ML 5.4, 2011/07/07). However, we do not know of any recent or active crustal contractional structure within this oceanic domain. In this study, we use new 12-channel high-resolution seismic data (FABLES seismic cruise, 2012, R/V Tethys II) in order to image the sedimentary cover of the Ligurian oceanic basin, up to ~3km below the seabed, including the Plio-Quaternary and the Messinian sediment down to the bottom of the Messinian salt layer. Because the Messinian event is well dated (5.96-5.32 Ma) and well identified in the seismic data, it forms a clear marker that we use to characterize the recent deformation related to both mobile salt motion and crustal tectonics. About 50 km south of the margin offshore of Italy, we identify huge and complex salt walls that elongate SW-NE. Such salt walls, which cannot be explained by salt tectonics only, are interpreted as evidence of deep-seated crustal deformation. They form en echelon structures that are well expressed in the seabed morphology, and do not correspond to any significant vertical throw at the base of the salt layer. This suggests that within the deep basin, mainly strike-slip faulting accommodates long-term crustal deformation. It thus offers a contrast with the margin where deformation is mainly marked by shortening and reverse faulting, with vertical throws of several hundred meters. This discrepancy in the tectonic styles between the margin and the adjacent oceanic basin suggests some partitioning of the deformation. It may result from the difference in the topographic gradient of the main crustal interfaces between the steep margin and the adjacent oceanic domain, and/or to different mechanical behaviours of the adjacent lithospheric domains.

Structure and regional significance of the Late Permian(?) Sierra Nevada - Death Valley thrust system, east-central California

USGS Publications Warehouse

Stevens, C.H.; Stone, P.

2005-01-01

An imbricate system of north-trending, east-directed thrust faults of late Early Permian to middle Early Triassic (most likely Late Permian) age forms a belt in east-central California extending from the Mount Morrison roof pendant in the eastern Sierra Nevada to Death Valley. Six major thrust faults typically with a spacing of 15-20 km, original dips probably of 25-35??, and stratigraphic throws of 2-5 km compose this structural belt, which we call the Sierra Nevada-Death Valley thrust system. These thrusts presumably merge into a de??collement at depth, perhaps at the contact with crystalline basement, the position of which is unknown. We interpret the deformation that produced these thrusts to have been related to the initiation of convergent plate motion along a southeast-trending continental margin segment probably formed by Pennsylvanian transform truncation. This deformation apparently represents a period of tectonic transition to full-scale convergence and arc magmatism along the continental margin beginning in the Late Triassic in central California. ?? 2005 Elsevier B.V. All rights reserved.

Unravelling detailed kinematics of DSGSD morphostructures (Moosfluh, Swiss Alps)

NASA Astrophysics Data System (ADS)

Loew, Simon; Glueer, Franziska; Manconi, Andrea

2017-04-01

The Great Aletsch Glacier (Swiss Alps) is experiencing a remarkable retreat with rates in the order of 50 meters every year. In the current glacier tongue area, where several pre-existing landslides have been partially or completely unloaded from the glacier ice mass during the last 150 years, various types of landslide reactions (in terms of type, size and velocity) can be reconstructed and observed. In particular, a deep-seated gravitational slope instability located in the area called "Moosfluh" has shown during the past 20 years evidences of slow but progressive increase of surface displacement. The moving mass of the Moosfluh DSGSD affects an area of about 2 km2 and entails a volume estimated in the order of 150-200 Mm3. This DSGSD in gneissic rocks affects the entire slope and extents several 100 meters beyond the ridge separating the Aletsch from the Rhone valley. The slope morphology is complex and many ridges and depressions striking parallel to the slope have been observed and mapped in the past. Some of these ridges correspond to glacial trim lines, and could be dated as Egesen and Little Ice Age glacial re-advance stages. Other slope parallel structures were explained as up- and down-hill facing scarps, i.e. internal rupture planes, and most uphill facing scarps oriented parallel to the Alpine foliation were interpreted as toppling phenomena. However, most these structural and kinematic interpretations remained hypotheses, as all morphostructures were covered by soil and vegetation and no borehole displacement data were available, excluding direct verification of morphostructural interpretations. This is in fact a typical situation for many Alpine DSGSD, where observed phenomena developed slowly over long periods of time and can have many different structural and kinematic origins. In late summer 2016, an unusual acceleration of the Moosfluh DSGSD was observed in the central part of the landslide. Compared to previous years, when annual ground deformations were in the order of few centimeters or decimeters, in the period September-October 2016 maximum velocities have reached locally 1 m/day. Between middle of September and middle of October, when displacement rates decelerated again, some sectors of the slope were displaced by up to 50 meters. During this period we monitored the evolution of the Moosfluh instability with two robotized total stations, several permanent GNSS stations and time-lapse cameras. Detailed mapping on ground surface and with helicopter based photogrammetry allowed to study internal deformation phenomena in detail, and to explore and unravel the displacement characteristics of all observed morphostructural features. We can show that slope parallel ridges and depressions have various structural origins. New uphill facing scarps in bedrock or soil cover, which formed between September and October 2016, are caused either by toppling with block rotations of up to 17 degrees, throws of several meters and slope parallel extensions of several tens of meters, or by antithetic normal faults. Many antithetic faults show slumping of the hanging wall block, are listric in shape and belong to asymmetric graben structures. Lateral transition from the central rapidly moving sectors into less deformed landslide mass is accommodated along steeply dipping transform faults or en-echelon sets of tensile fractures. Displacements along most of these features were quantified in terms of slip vectors (throw and heave), horizontal extension or rotation. Comparison with surface displacement vector fields derived from total station measurements and digital image correlation allows to assess and explain local variations in strain fields and to develop a semi-quantitative kinematic model of the entire DSGSD including its structures at depth.

Structural inheritance and selective reactivation in the central Andes: Cenozoic deformation guided by pre-Andean structures in southern Peru

NASA Astrophysics Data System (ADS)

Perez, Nicholas D.; Horton, Brian K.; Carlotto, Victor

2016-03-01

Structural, stratigraphic, and geochronologic constraints from the Eastern Cordillera in the central Andean plateau of southern Peru (14-15°S) demonstrate the existence and position of major pre-Andean structures that controlled the accumulation of Triassic synrift fill and guided subsequent Cenozoic deformation. The timing of initial clastic deposition of the Triassic Mitu Group is here constrained to ~ 242-233 Ma on the basis of detrital and volcanic zircon U-Pb geochronology. Regionally distinct provenance variations, as provided by U-Pb age populations from localized synrift accumulations, demonstrate Triassic erosion of multiple diagnostic sources from diverse rift-flank uplifts. Stratigraphic correlations suggest synchronous initiation of extensional basins containing the Mitu Group, in contrast with previous interpretations of southward rift propagation. Triassic motion along the NE-dipping San Anton normal fault accommodated up to 7 km of throw and hanging-wall deposition of a synrift Mitu succession > 2.5 km thick. The contrasting orientation of a non-reactivated Triassic normal fault suggests selective inversion of individual structures in the Eastern Cordillera was dependent on fault dip and strike. Selective preservation of a ~ 4 km thick succession of Carboniferous-Permian strata in the down-dropped San Anton hanging wall, beneath the synrift Mitu Group, suggests large-scale erosional removal in the uplifted footwall. Field and map observations identify additional pre-Andean thrust faults and folds attributed to poorly understood Paleozoic orogenic events preserved in the San Anton hanging wall. Selective thrust reactivation of normal and reverse faults during later compression largely guided Cenozoic deformation in the Eastern Cordillera. The resulting structural compartmentalization and across-strike variations in kinematics and deformation style highlight the influence of inherited Paleozoic structures and Triassic normal faults on the long-term history of convergent margin deformation in the Andes.

MHDL CAD tool with fault circuit handling

NASA Astrophysics Data System (ADS)

Espinosa Flores-Verdad, Guillermo; Altamirano Robles, Leopoldo; Osorio Roque, Leticia

2003-04-01

Behavioral modeling and simulation, with Analog Hardware and Mixed Signal Description High Level Languages (MHDLs), have generated the development of diverse simulation tools that allow handling the requirements of the modern designs. These systems have million of transistors embedded and they are radically diverse between them. This tendency of simulation tools is exemplified by the development of languages for modeling and simulation, whose applications are the re-use of complete systems, construction of virtual prototypes, realization of test and synthesis. This paper presents the general architecture of a Mixed Hardware Description Language, based on the standard 1076.1-1999 IEEE VHDL Analog and Mixed-Signal Extensions known as VHDL-AMS. This architecture is novel by consider the modeling and simulation of faults. The main modules of the CAD tool are briefly described in order to establish the information flow and its transformations, starting from the description of a circuit model, going throw the lexical analysis, mathematical models generation and the simulation core, ending at the collection of the circuit behavior as simulation"s data. In addition, the incorporated mechanisms to the simulation core are explained in order to realize the handling of faults into the circuit models. Currently, the CAD tool works with algebraic and differential descriptions for the circuit models, nevertheless the language design is open to be able to handle different model types: Fuzzy Models, Differentials Equations, Transfer Functions and Tables. This applies for fault models too, in this sense the CAD tool considers the inclusion of mutants and saboteurs. To exemplified the results obtained until now, the simulated behavior of a circuit is shown when it is fault free and when it has been modified by the inclusion of a fault as a mutant or a saboteur. The obtained results allow the realization of a virtual diagnosis for mixed circuits. This language works in a UNIX system; it was developed with an object-oriented methodology and programmed in C++.

Comparison of In-Season-Specific Resistance vs. A Regular Throwing Training Program on Throwing Velocity, Anthropometry, and Power Performance in Elite Handball Players.

PubMed

Hermassi, Souhail; van den Tillaar, Roland; Khlifa, Riadh; Chelly, Mohamed Souhaiel; Chamari, Karim

2015-08-01

The purpose of this study was to compare the effect of a specific resistance training program (throwing movement with a medicine ball) with that of regular training (throwing with regular balls) on ball velocity, anthropometry, maximal upper-body strength, and power. Thirty-four elite male team handball players (age: 18 ± 0.5 years, body mass: 80.6 ± 5.5 kg, height: 1.80 ± 5.1 m, body fat: 13.4 ± 0.6%) were randomly assigned to 1 of the 3 groups: control (n = 10), resistance training group (n = 12), or regular throwing training group (n = 12). Over the 8-week in season, the athletes performed 3 times per week according to an assigned training program alongside their normal team handball training. One repetition maximum (1RM) bench press and 1RM pullover scores assessed maximal arm strength. Anthropometry was assessed by body mass, fat percentage, and muscle volumes of upper body. Handball throwing velocity was measured by a standing throw, a throw with run, and a jump throw. Power was measured by measuring total distance thrown by a 3-kg medicine ball overhead throw. Throwing ball velocity, maximal strength, power, and muscle volume increases for the specific resistance training group after the 8 weeks of training, whereas only maximal strength, muscle volume and power and in the jump throw increases were found for the regular throwing training group. No significant changes for the control group were found. The current findings suggest that elite male handball players can improve ball velocity, anthropometrics, maximal upper-body strength, and power during the competition season by implementing a medicine ball throwing program.

Effects of Various Warm Up Protocol on Special Judo Fitness Test Performance.

PubMed

Lum, Danny

2017-02-13

The purposed of this study was to compare the effects of postactivation potentiation (PAP) on Special Judo Fitness Test (SJFT) performance using explosive exercises that activates upper and lower limbs muscles. Eleven male judo athletes (mean ± SD, age, 16 - 29 years; height, 170 ± 7 cm; body mass, 73 ± 16 kg) attended four separate sessions. The first session was used to familiarise the subjects to the experimental procedure, the SJFT, the high pull test (HPT) and the two explosive exercises including resistance band pull and standing broad jump. Subsequently, subjects were randomly assigned in a counterbalanced manner to either perform the upper and lower body PAP (ULB), lower body PAP (LB) or usual competition (CON) warm up routine prior to performing the HPT and SJFT. The following variables were quantified: throws performed during series A, B, and C; total number of throws; heart rate immediately and 1 minute after the test; test index; peak power; and RPE after warm up. During series 1, number of throws performed in LB and ULB were significantly greater than CON (p < 0.05). Only ULB resulted in significantly greater number of total throws (p < 0.01) and higher peak power (p < 0.01) than CON. The RPE for both LB and ULB were significantly lower than CON (p < 0.01). Peak power was moderately correlated to total number of throws performed (r=0.4, p < 0.05). This study suggest that performing ULB before SJFT can result in improved performance and peak power.

Fault geometric complexity and how it may cause temporal slip-rate variation within an interacting fault system

NASA Astrophysics Data System (ADS)

Zielke, Olaf; Arrowsmith, Ramon

2010-05-01

Slip-rates along individual faults may differ as a function of measurement time scale. Short-term slip-rates may be higher than the long term rate and vice versa. For example, vertical slip-rates along the Wasatch Fault, Utah are 1.7+/-0.5 mm/yr since 6ka, <0.6 mm/yr since 130ka, and 0.5-0.7 mm/yr since 10Ma (Friedrich et al., 2003). Following conventional earthquake recurrence models like the characteristic earthquake model, this observation implies that the driving strain accumulation rates may have changed over the respective time scales as well. While potential explanations for such slip-rate variations may be found for example in the reorganization of plate tectonic motion or mantle flow dynamics, causing changes in the crustal velocity field over long spatial wavelengths, no single geophysical explanation exists. Temporal changes in earthquake rate (i.e., event clustering) due to elastic interactions within a complex fault system may present an alternative explanation that requires neither variations in strain accumulation rate or nor changes in fault constitutive behavior for frictional sliding. In the presented study, we explore this scenario and investigate how fault geometric complexity, fault segmentation and fault (segment) interaction affect the seismic behavior and slip-rate along individual faults while keeping tectonic stressing-rate and frictional behavior constant in time. For that, we used FIMozFric--a physics-based numerical earthquake simulator, based on Okada's (1992) formulations for internal displacements and strains due to shear and tensile faults in a half-space. Faults are divided into a large number of equal-sized fault patches which communicate via elastic interaction, allowing implementation of geometrically complex, non-planar faults. Each patch has assigned a static and dynamic friction coefficient. The difference between those values is a function of depth--corresponding to the temperature-dependence of velocity-weakening that is observed in laboratory friction experiments and expressed in an [a-b] term in Rate-State-Friction (RSF) theory. Patches in the seismic zone are incrementally loaded during the interseismic phase. An earthquake initiates if shear stress along at least one (seismic) patch exceeds its static frictional strength and may grow in size due to elastic interaction with other fault patches (static stress transfer). Aside from investigating slip-rate variations due to the elastic interactions within a fault system with this tool, we want to show how such modeling results can be very useful in exploring the physics underlying the patterns that the paleoseismology sees and that those methods (simulation and observations) can be merged, with both making important contributions. Using FIMozFric, we generated synthetic seismic records for a large number of fault geometries and structural scenarios to investigate along-fault slip accumulation patterns and the variability of slip at a point. Our simulations show that fault geometric complexity and the accompanied fault interactions and multi-fault ruptures may cause temporal deviations from the average fault slip-rate, in other words phases of earthquake clustering or relative quiescence. Slip-rates along faults within an interacting fault system may change even when the loading function (stressing rate) remains constant and the magnitude of slip rate change is suggested to be proportional to the magnitude of fault interaction. Thus, spatially isolated and structurally mature faults are expected to experience less slip-rate changes than strongly interacting and less mature faults. The magnitude of slip-rate change may serve as a proxy for the magnitude of fault interaction and vice versa.

Growth and linkage of the quaternary Ubrique Normal Fault Zone, Western Gibraltar Arc: role on the along-strike relief segmentation

NASA Astrophysics Data System (ADS)

Jiménez-Bonilla, Alejandro; Balanya, Juan Carlos; Exposito, Inmaculada; Diaz-Azpiroz, Manuel; Barcos, Leticia

2015-04-01

Strain partitioning modes within migrating orogenic arcs may result in arc-parallel stretching that produces along-strike structural and topographic discontinuities. In the Western Gibraltar Arc, arc-parallel stretching has operated from the Lower Miocene up to recent times. In this study, we have reviewed the Colmenar Fault, located at the SW end of the Subbetic ranges, previously interpreted as a Middle Miocene low-angle normal fault. Our results allow to identify younger normal fault segments, to analyse their kinematics, growth and segment linkage, and to discuss its role on the structural and relief drop at regional scale. The Colmenar Fault is folded by post-Serravallian NE-SW buckle folds. Both the SW-dipping fault surfaces and the SW-plunging fold axes contribute to the structural relief drop toward the SW. Nevertheless, at the NW tip of the Colmenar Fault, we have identified unfolded normal faults cutting quaternary soils. They are grouped into a N110˚E striking brittle deformation band 15km long and until 3km wide (hereafter Ubrique Normal Fault Zone; UNFZ). The UNFZ is divided into three sectors: (a) The western tip zone is formed by normal faults which usually dip to the SW and whose slip directions vary between N205˚E and N225˚E. These segments are linked to each other by left-lateral oblique faults interpreted as transfer faults. (b) The central part of the UNFZ is composed of a single N115˚E striking fault segment 2,4km long. Slip directions are around N190˚E and the estimated throw is 1,25km. The fault scarp is well-conserved reaching up to 400m in its central part and diminishing to 200m at both segment terminations. This fault segment is linked to the western tip by an overlap zone characterized by tilted blocks limited by high-angle NNE-SSW and WNW-ESE striking faults interpreted as "box faults" [1]. (c) The eastern tip zone is formed by fault segments with oblique slip which also contribute to the downthrown of the SW block. This kinematic pattern seems to be related to other strike-slip fault systems developed to the E of the UNFZ. The structural revision together with updated kinematic data suggest that the Colmenar Fault is cut and downthrown by a younger normal fault zone, the UNFZ, which would have contributed to accommodate arc-parallel stretching until the Quaternary. This stretching provokes along-strike relief segmentation, being the UNFZ the main fault zone causing the final drop of the Subbetic ranges towards the SW within the Western Gibraltar Arc. Our results show displacement variations in each fault segment of the UNFZ, diminishing to their tips. This suggests fault segment linkage finally evolved to build the nearly continuous current fault zone. The development of current large through-going faults linked inside the UNFZ is similar to those ones simulated in some numerical modelling of rift systems [2]. Acknowledgements: RNM-415 and CGL-2013-46368-P [1]Peacock, D.C.P., Knipe, R.J., Sanderson, D.J., 2000. Glossary of normal faults. Journal Structural Geology, 22, 291-305. [2]Cowie, P.A., Gupta, S., Dawers, N.H., 2000. Implications of fault array evolution for synrift depocentre development: insights from a numerical fault growth model. Basin Research, 12, 241-261.

Movement variability and skill level of various throwing techniques.

PubMed

Wagner, Herbert; Pfusterschmied, Jürgen; Klous, Miriam; von Duvillard, Serge P; Müller, Erich

2012-02-01

In team-handball, skilled athletes are able to adapt to different game situations that may lead to differences in movement variability. Whether movement variability affects the performance of a team-handball throw and is affected by different skill levels or throwing techniques has not yet been demonstrated. Consequently, the aims of the study were to determine differences in performance and movement variability for several throwing techniques in different phases of the throwing movement, and of different skill levels. Twenty-four team-handball players of different skill levels (n=8) performed 30 throws using various throwing techniques. Upper body kinematics was measured via an 8 camera Vicon motion capture system and movement variability was calculated. Results indicated an increase in movement variability in the distal joint movements during the acceleration phase. In addition, there was a decrease in movement variability in highly skilled and skilled players in the standing throw with run-up, which indicated an increase in the ball release speed, which was highest when using this throwing technique. We assert that team-handball players had the ability to compensate an increase in movement variability in the acceleration phase to throw accurately, and skilled players were able to control the movement, although movement variability decreased in the standing throw with run-up. Copyright © 2011 Elsevier B.V. All rights reserved.

Kinematic Analysis of Line-Out Throwing in Elite International Rugby Union

PubMed Central

Sayers, Mark G.L.

2011-01-01

The rugby union line-out is a key aspect of game play and involves players from both teams contesting for the ball after it has been thrown in from the side line. Successful lines-out throws require the ball to be delivered accurately to the hands of a jumping and/or lifted team mate (approximately 3-3.5 m off the ground) over distances of between 5- 18 m. Previous research has suggested considerable inter and intra-individual differences in the throwing techniques of international level players. Accordingly, this project investigated the interrelationships between accuracy and the line-out throwing characteristics of three elite international rugby players, and then analyzed whether these changed for throws over increasing length. Three-dimensional (3D) data were developed from video footage (50 Hz) of three elite international subjects for 30 throws over three distances (6 m, 10 m, and 15 m). Results showed notable differences between subjects in many variables at each of the key throw phases. However, several variables such as the degree of trunk flexion at the end of the backswing and at ball release, coupled with elbow flexion angle at ball release remained constant as throw length increased. All subjects exhibited high levels of consistency in movement patterns across all throw lengths. Findings indicated that these high performance line-out throwers shared several common characteristics that will provide useful guides in the development of training programs. Key points A key aspect of this research was the assessment of throwing accuracy using a functional throwing task that mimicked normal performance. Although individual differences in throwing technique occurred, several technical aspects of the throw were common to each of these elite international players. Subjects tended to be extremely consistent in the way they positioned the ball at the end of the backswing, and had very consistent elbow (flexion) and shoulder (flexion and abduction) angles at both the end of the backswing and at ball release. In addition, throwers kept the trunk close to upright during the throw with minimal trunk flexion or extension regardless of throw distance. To throw for longer distances participants tended to increase the involvement of the legs. PMID:24150632

Research on criticality analysis method of CNC machine tools components under fault rate correlation

NASA Astrophysics Data System (ADS)

Gui-xiang, Shen; Xian-zhuo, Zhao; Zhang, Ying-zhi; Chen-yu, Han

2018-02-01

In order to determine the key components of CNC machine tools under fault rate correlation, a system component criticality analysis method is proposed. Based on the fault mechanism analysis, the component fault relation is determined, and the adjacency matrix is introduced to describe it. Then, the fault structure relation is hierarchical by using the interpretive structure model (ISM). Assuming that the impact of the fault obeys the Markov process, the fault association matrix is described and transformed, and the Pagerank algorithm is used to determine the relative influence values, combined component fault rate under time correlation can obtain comprehensive fault rate. Based on the fault mode frequency and fault influence, the criticality of the components under the fault rate correlation is determined, and the key components are determined to provide the correct basis for equationting the reliability assurance measures. Finally, taking machining centers as an example, the effectiveness of the method is verified.

Relationship among maximal grip, throwing velocity and anthropometric parameters in elite water polo players.

PubMed

Ferragut, C; Vila, H; Abraldes, J A; Argudo, F; Rodriguez, N; Alcaraz, P E

2011-03-01

As independent aspects, body size, body composition, and physiological performance of elite athletes have aroused the interest of sports scientists but, unfortunately, studies that combine these aspects are scarcely avalaible in water polo. The aim of the present study was to: 1) to develop an anthropometric profile of highly skilled male Water Polo players, and 2) to identify significant relationships between these features and overhead throwing velocity in highly skilled male water polo players. Thirteen male water polo players, with a mean age of 26.10±4.82, were recruited from the Spanish Water Polo team and an anthropometric assessment on all of them was carried out. Throwing velocity was evaluated in three different situations from the 5 m-penalty line on the center of the water polo goal: A) throwing without a defender nor a goalkeeper; B) throwing with a goalkeeper only, and C) 3) armfuls running shot with goalkeeper. Maximal handgrip was also tested. Biacromial breadth shows a significative correlation with hand grip in water polo players (r=0.792; P=0.001) and also correlates with Throwing velocity (r=0.716; P<0.001). Biepicondylar femur breadth correlates significatively with hand grip (r=0.727; P<0.05) and also with throwing velocity in "throwing with goalkeeper" situation (r=0.664; P<0.05). Hand grip shows a significant correlation with throwing velocity in "throwing with goalkeeper" situation (r=0.603; P<0.05). In conclusion, body mass aspects are not related with throwing velocity in highly skilled Water Polo players. Maximal hand grip is related with throwing velocity in "throwing with goalkeeper" situation. More investigations about water polo are necessary.

Automatic Detection of Pitching and Throwing Events in Baseball With Inertial Measurement Sensors.

PubMed

Murray, Nick B; Black, Georgia M; Whiteley, Rod J; Gahan, Peter; Cole, Michael H; Utting, Andy; Gabbett, Tim J

2017-04-01

Throwing loads are known to be closely related to injury risk. However, for logistic reasons, typically only pitchers have their throws counted, and then only during innings. Accordingly, all other throws made are not counted, so estimates of throws made by players may be inaccurately recorded and underreported. A potential solution to this is the use of wearable microtechnology to automatically detect, quantify, and report pitch counts in baseball. This study investigated the accuracy of detection of baseball pitching and throwing in both practice and competition using a commercially available wearable microtechnology unit. Seventeen elite youth baseball players (mean ± SD age 16.5 ± 0.8 y, height 184.1 ± 5.5 cm, mass 78.3 ± 7.7 kg) participated in this study. Participants performed pitching, fielding, and throwing during practice and competition while wearing a microtechnology unit. Sensitivity and specificity of a pitching and throwing algorithm were determined by comparing automatic measures (ie, microtechnology unit) with direct measures (ie, manually recorded pitching counts). The pitching and throwing algorithm was sensitive during both practice (100%) and competition (100%). Specificity was poorer during both practice (79.8%) and competition (74.4%). These findings demonstrate that the microtechnology unit is sensitive to detect pitching and throwing events, but further development of the pitching algorithm is required to accurately and consistently quantify throwing loads using microtechnology.

Self-Paced and Temporally Constrained Throwing Performance by Team-Handball Experts and Novices without Foreknowledge of Target Position

PubMed Central

Rousanoglou, Elissavet N.; Noutsos, Konstantinos S.; Bayios, Ioannis A.; Boudolos, Konstantinos D.

2015-01-01

The fixed duration of a team-handball game and its continuously changing situations incorporate an inherent temporal pressure. Also, the target’s position is not foreknown but online determined by the player’s interceptive processing of visual information. These ecological limitations do not favour throwing performance, particularly in novice players, and are not reflected in previous experimental settings of self-paced throws with foreknowledge of target position. The study investigated the self-paced and temporally constrained throwing performance without foreknowledge of target position, in team-handball experts and novices in three shot types (Standing Shot, 3Step Shot, Jump Shot). The target position was randomly illuminated on a tabloid surface before (self-paced condition) and after (temporally constrained condition) shot initiation. Response time, throwing velocity and throwing accuracy were measured. A mixed 2 (experience) X 2 (temporal constraint condition) ANOVA was applied. The novices performed with significantly lower throwing velocity and worse throwing accuracy in all shot types (p = 0.000) and, longer response time only in the 3Step Shot (p = 0.013). The temporal constraint (significantly shorter response times in all shot types at p = 0.000) had a shot specific effect with lower throwing velocity only in the 3Step Shot (p = 0.001) and an unexpected greater throwing accuracy only in the Standing Shot (p = 0.002). The significant interaction between experience and temporal constraint condition in throwing accuracy (p = 0.003) revealed a significant temporal constraint effect in the novices (p = 0.002) but not in the experts (p = 0.798). The main findings of the study are the shot specificity of the temporal constraint effect, as well as that, depending on the shot, the novices’ throwing accuracy may benefit rather than worsen under temporal pressure. Key points The temporal constraint induced a shot specific significant difference in throwing velocity in both the experts and the novices. The temporal constraint induced a shot specific significant difference in throwing accuracy only in the novices. Depending on the shot demands, the throwing accuracy of the novices may benefit under temporally constrained situations. PMID:25729288

Defining the Long-Toss: A Professional Baseball Epidemiological Study

PubMed Central

Stone, Austin V.; Mannava, Sandeep; Patel, Anita; Marquez-Lara, Alejandro; Freehill, Michael T.

2017-01-01

Background: Despite widespread use of long-toss throwing in baseball as a component of arm conditioning, interval throwing programs, and rehabilitation, long-toss distance and throwing mechanics remain controversial. Purpose: To ascertain the perceived definition of long-toss throwing through a survey of professional pitchers, pitching coaches (PCs), and certified athletic trainers (ATCs) associated with Major League Baseball. Study Design: Descriptive epidemiology study. Methods: Pitchers, PCs, and ATCs associated with 5 Major League Baseball organizations completed an anonymous survey that collected demographic data, personal use of long-toss throwing, and their perception of the distance and throwing mechanics that comprised long-toss. Results: A total of 321 surveys were completed by 271 pitchers, 19 PCs, and 31 ATCs. For all respondents, the mean distance considered as long-toss was 175 ft (95% CI, 170-181 ft). Respondents categorized the throwing mechanics of long-toss, with 36% reporting throwing “on a line” and 70% reporting long-toss as “not on a line.” Of those throwing “on a line,” 28% reported using crow-hop footwork while 60% used crow-hop footwork when throwing “not on a line.” Interpretation of long-toss distance significantly varied by position: pitchers, 177 ft (95% CI, 171-183 ft); PCs, 177 ft (95% CI, 155-200 ft); and ATCs, 157 ft (95% CI, 144-169 ft) (P = .048). When asked when long-toss throwing is used, pitchers reported using it more frequently in preseason (P = .007), during the season (P = .015), and in the off-season (P = .002) compared with that by ATCs. Functional goals for long-toss throwing demonstrated that pitchers and PCs use long-toss for shoulder stretching more frequently than ATCs (P < .001 and P = .026, respectively). ATCs used long-toss more than pitchers for interval throwing programs (P < .001). Conclusion: The definition varies for long-toss throwing distance and throwing mechanics. Pitchers and PCs believe that long-toss comprised longer distances than ATCs and employed long-toss differently for strength conditioning, training, stretching, and rehabilitation. This discrepancy highlights a potential lost opportunity for protecting the shoulder. While long-toss is an important tool, a more scientific definition is warranted to better elucidate its role in enhancing throwing performance and rehabilitation. PMID:28255565

Comparison of GPS and Quaternary slip rates: Insights from a new Quaternary fault database for Central Asia

NASA Astrophysics Data System (ADS)

Mohadjer, Solmaz; Ehlers, Todd; Bendick, Rebecca; Mutz, Sebastian

2016-04-01

Previous studies related to the kinematics of deformation within the India-Asia collision zone have relied on slip rate data for major active faults to test kinematic models that explain the deformation of the region. The slip rate data, however, are generally disputed for many of the first-order faults in the region (e.g., Altyn Tagh and Karakorum faults). Several studies have also challenged the common assumption that geodetic slip rates are representative of Quaternary slip rates. What has received little attention is the degree to which geodetic slip rates relate to Quaternary slip rates for active faults in the India-Asia collision zone. In this study, we utilize slip rate data from a new Quaternary fault database for Central Asia to determine the overall relationship between Quaternary and GPS-derived slip rates for 18 faults. The preliminary analysis investigating this relationship uses weighted least squares and a re-sampling analysis to test the sensitivity of this relationship to different data point attributes (e.g., faults associated with data points and dating methods used for estimating Quaternary slip rates). The resulting sample subsets of data points yield a maximum possible Pearson correlation coefficient of ~0.6, suggesting moderate correlation between Quaternary and GPS-derived slip rates for some faults (e.g., Kunlun and Longmen Shan faults). Faults with poorly correlated Quaternary and GPS-derived slip rates were identified and dating methods used for the Quaternary slip rates were examined. Results indicate that a poor correlation between Quaternary and GPS-derived slip rates exist for the Karakorum and Chaman faults. Large differences between Quaternary and GPS slip rates for these faults appear to be connected to qualitative dating of landforms used in the estimation of the Quaternary slip rates and errors in the geomorphic and structural reconstruction of offset landforms (e.g., offset terrace riser reconstructions for Altyn Tagh fault). Other factors such as a low density in the GPS network (e.g., GPS rate based on data from a single station for the Karakorum fault) appear to also contribute to the mismatch observed between the slip rates. Taken together, these results suggest that GPS-derived slip rates are often (but not always) representative of Quaternary slip rates and that the dating methods and sampling approaches used to identify transients in a fault slip rate history should be heavily scrutinized before interpreting the seismic hazards for a region.

Kinetics of throwing arm joints and the trunk motion during an overarm distance throw by skilled Japanese elementary school boys.

PubMed

Kobayashi, Yasuto; Ae, Michiyoshi; Miyazaki, Akiyo; Fujii, Norihisa; Iiboshi, Akira; Nakatani, Hideki

2016-09-01

The purpose of this study was to investigate joint kinetics of the throwing arms and role of trunk motion in skilled elementary school boys during an overarm distance throw. Throwing motions of 42 boys from second, fourth, and sixth grade were videotaped with three high-speed cameras operating at 300 fps. Seven skilled boys from each grade were selected on the basis of throwing distance for three-dimensional kinetic analysis. Joint forces, torques, and torque powers of the throwing arm joints were calculated from reconstructed three-dimensional coordinate data smoothed at cut-off frequencies of 10.5-15 Hz and by the inverse dynamics method. Throwing distance and ball velocity significantly increased with school grade. The angular velocity of elbow extension before ball release increased with school grade, although no significant increase between the grades was observed in peak extension torque of elbow joint. The joint torque power of shoulder internal/external rotation tended to increase with school grade. When teaching the overarm throw, elementary school teachers should observe large backward twisting of trunk during the striding phase and should keep in mind that young children, such as second graders (age 8 years), will be unable to effectively utilise shoulder external/internal rotation during the throwing phase.

Unknown loads affect force production capacity in early phases of bench press throws.

PubMed

Hernández Davó, J L; Sabido Solana, R; Sarabia Marínm, J M; Sánchez Martos, Á; Moya Ramón, M

2015-10-01

Explosive strength training aims to improve force generation in early phases of movement due to its importance in sport performance. The present study examined the influence of lack of knowledge about the load lifted in explosive parameters during bench press throws. Thirteen healthy young men (22.8±2.0 years) participated in the study. Participants performed bench press throws with three different loads (30, 50 and 70% of 1 repetition maximum) in two different conditions (known and unknown loads). In unknown condition, loads were changed within sets in each repetition and participants did not know the load, whereas in known condition the load did not change within sets and participants had knowledge about the load lifted. Results of repeated-measures ANOVA revealed that unknown conditions involves higher power in the first 30, 50, 100 and 150 ms with the three loads, higher values of ratio of force development in those first instants, and differences in time to reach maximal rate of force development with 50 and 70% of 1 repetition maximum. This study showed that unknown conditions elicit higher values of explosive parameters in early phases of bench press throws, thereby this kind of methodology could be considered in explosive strength training.

The biomechanics of javelin throwing: a review.

PubMed

Bartlett, R M; Best, R J

1988-01-01

In this paper, the scientific literature and that on the sports sciences relevant to javelin throwing is critically reviewed. This is particularly timely because of the change in the specification of the javelin for the men's event, which was introduced by the IAAF in 1986. A full discussion of the aerodynamics of the javelin is presented with due consideration of the change in pitching moment characteristics that the rules change had brought about. The uses and limitations of current computer programs for simulating javelin flight, in order to estimate optimal release parameters, are profiled. Consideration is also given to the effects of wind velocity, air density, javelin weight and the flutter and spin of the javelin on its flight. The review further considers the optimization of release parameters, drawing upon computer simulations and field-based data. The effects of release speed, release height, release angle, release angle of attack and release pitch rate are assessed. The javelin throwing technique is discussed in relation to cinematographically derived data, including an evaluation of experimental procedures. The importance to successful performance of the grip, the run-up and transition phases, the cross over and delivery strides are each reviewed. Finally, some prognoses as to the direction of future research into this complex throwing skill are offered.

Architectural and microstructural characterization of a seismogenic normal fault in dolostones (Central Apennines, Italy)

NASA Astrophysics Data System (ADS)

Demurtas, Matteo; Fondriest, Michele; Clemenzi, Luca; Balsamo, Fabrizio; Storti, Fabrizio; Di Toro, Giulio

2015-04-01

Fault zones cutting carbonate sequences represent significant seismogenic sources worldwide (e.g. L'Aquila 2009, MW 6.1). Though seismological and geophysical techniques (double differences method, trapped waves, etc.) allow us to investigate down to the decametric scale the structure of active fault zones, further geological field surveys and microstructural studies of exhumed seismogenic fault zones are required to support interpretation of geophysical data, quantify the geometry of fault zones and identify the fault processes active during the seismic cycle. Here we describe the architecture (i.e. fault geometry and fault rock distribution) of the well-exposed footwall-block of the Campo Imperatore Fault Zone (CIFZ) by means of remote sensed analyses, field surveys, mineralogical (XRD, micro-Raman spectroscopy) and microstructural (FE-SEM, optical microscope cathodoluminescence) investigations. The CIFZ dips 58° towards N210 and its strike mimics that of the arcuate Gran Sasso Thrust Belt (Central Apennines). The CIFZ was exhumed from 2-3 km depth and accommodated a normal throw of ~2 km starting from the Early-Pleistocene. In the studied area, the CIFZ puts in contact the Holocene deposits at the hangingwall with dolomitized Jurassic carbonate platform successions (Calcare Massiccio) at the footwall. From remote sensed analyses, structural lineaments both inside and outside the CIFZ have a typical NW-SE Apenninic strike, which is parallel to the local trend of the Gran Sasso Thrust. Based on the density of the fracture/fault network and the type of fault zone rocks, we distinguished four main structural domains within the ~300 m thick CIFZ footwall-block, which include (i) a well-cemented (white in color) cataclastic zone (up to ~40 m thick) at the contact with the Holocene deposits, (ii) a well-cemented (brown to grey in color) breccia zone (up to ~15 m thick), (iii) an high strain damage zone (fracture spacing < 2-3 cm), and (iv) a low strain damage zone (fracture spacing > 10 cm). Other than by the main boundary normal fault, slip was accommodated in the cataclastic zone by minor sub-parallel synthetic and antithetic normal faults and by few tear strike-slip fault; the rest of the footwall shows progressively less pervasive damage down to the background intensity of deformation. High strain domains include (1) pervasively fragmented dolostones with radial fractures (evidence of in-situ shattering), (2) shiny (mirror-like) fault surfaces truncating dolostone clasts, (3) mm-thick ultra-cataclastic layers with lobate and cuspate boundaries, (4) mixed calcite-dolomite "foliated cataclasites". The above microstructures can be associated with seismic faulting. Fluids infiltration during deformation is attested by the occurrence of multiple generations of carbonate-filled veins, often exploited as minor faults with a mylonite-like fabric (e.g. presence of micrometer in size euhedral calcite grains). The attitude of the studied segment of the CIFZ, the thickness of the footwall block and the kinematics of the minor faults compares well with the hypocentral and focal mechanisms distribution typical of the earthquake sequences in the Apennines. In particular, the CIFZ can be considered as an exhumed analogue of the normal fault system that caused the L'Aquila 2009 seismic sequence.

Comparison of three baseball-specific 6-week training programs on throwing velocity in high school baseball players.

PubMed

Escamilla, Rafael F; Ionno, Michele; deMahy, M Scott; Fleisig, Glenn S; Wilk, Kevin E; Yamashiro, Kyle; Mikla, Tony; Paulos, Lonnie; Andrews, James R

2012-07-01

Throwing velocity is an important baseball performance variable for baseball pitchers, because greater throwing velocity results in less time for hitters to make a decision to swing. Throwing velocity is also an important baseball performance variable for position players, because greater throwing velocity results in decreased time for a runner to advance to the next base. This study compared the effects of 3 baseball-specific 6-week training programs on maximum throwing velocity. Sixty-eight high school baseball players 14-17 years of age were randomly and equally divided into 3 training groups and a nontraining control group. The 3 training groups were the Throwers Ten (TT), Keiser Pneumatic (KP), and Plyometric (PLY). Each training group trained 3 d·wk(-1) for 6 weeks, which comprised approximately 5-10 minutes for warm-up, 45 minutes of resistance training, and 5-10 for cool-down. Throwing velocity was assessed before (pretest) and just after (posttest) the 6-week training program for all the subjects. A 2-factor repeated measures analysis of variance with post hoc paired t-tests was used to assess throwing velocity differences (p < 0.05). Compared with pretest throwing velocity values, posttest throwing velocity values were significantly greater in the TT group (1.7% increase), the KP group (1.2% increase), and the PLY group (2.0% increase) but not significantly different in the control group. These results demonstrate that all 3 training programs were effective in increasing throwing velocity in high school baseball players, but the results of this study did not demonstrate that 1 resistance training program was more effective than another resistance training program in increasing throwing velocity.

Gender Differences in Motor Skills of the Overarm Throw

PubMed Central

Gromeier, Michael; Koester, Dirk; Schack, Thomas

2017-01-01

In this cross-sectional study, the qualitative and quantitative throwing performance of male and female athletes (6 to 16 years of age) was analyzed. The goal of this study was to assess whether there were gender based qualitative and quantitative differences in throwing performance of young athletes, throughout three different age bands (childhood, pubescence, and adolescence). Furthermore, we explored whether all components of the throwing movement are equally affected by gender differences. Focus was placed on five essential components of action: trunk, forearm, humerus, stepping, and backswing. Therefore, children and adolescents (N = 96) were invited to throw three times from three different distances, while aiming at a target placed at shoulder height. The participants were aspiring athletes, competitive in the sport handball. For analyzing the quality of movement the component approach of Halverson and Roberton (1984) was used. The throwing accuracy was noted and used to evaluate the quantitative performance of the throwing movement. Throughout three different age bands, no statistically significant difference was found between genders in throwing accuracy, i.e., quantitative performance. Regarding the qualitative evaluation of the throwing movement, male and female athletes differed significantly. The component approach yielded higher scores for male than for female participants. As expected, with increasing age qualitative and quantitative performance of male and female athletes improved. These results suggest that there are gender-specific differences in qualitative throwing performance, but not necessarily in quantitative throwing performance. Exploration shows that differences in the qualitative throwing performance were seen in specific components of action. Male and female athletes demonstrated similar movement patterns in humerus and forearm actions, but differed in trunk, stepping, and backswing actions. PMID:28261142

Groundwater management in Cusco region, Peru Present and future challenges

NASA Astrophysics Data System (ADS)

Guttman, Joseph; Berger, Diego; Pumayalli Saloma, Rene

2013-04-01

The agriculture in the rural areas in the Andes Mountains at Cusco region-Peru is mainly rain fed agriculture and basically concentrated to one crop season per year. This situation limits the farmer's development. In order to increase the agricultural season into the winter period (May to November) also known as the dry season, many farmers are pumping water from streams or underground water that unfortunately leads to many of them becoming dry during the winter/dry season. In addition, some of those streams are polluted by the city's wastewater and heavy metals that are released from mines which are quite abundant in the Andes Mountains. The regional government through its engineering organization "Per Plan Meriss Inka", is trying to increase the water quantity and quality to the end users (farmers in the valleys) by promoting projects that among others include capturing of springs that emerge from the high mountain ridges, diverting streams and harvesting surface reservoirs. In the Ancahuasi area (Northwest of Cusco) are many springs that emerge along several geological faults that act as a border line between the permeable layers (mostly sandstone) in the upper throw of the fault and impermeable layers in the lower throw of the fault. The discharge of the springs varies in dependence to the size of each catchment area or aquifer structure. The spring water is collected in small pools and then by gravity through open channels to the farmers in the valleys. During the past 25 years, in some places, springs have been captured by horizontal wells (gallery) that were excavated from the fault zone into the mountain a few tens of meters below the spring outlet. The gallery drains excess water from the spring storage and increases the overall discharge. The galleries are a limited solution to individual places where the geology, hydrology and the topography enable it. The farmers are using flood irrigation systems which according to World Bank documents, the overall efficiency of such irrigation systems is about 35% (most of the water recharges to the underground or is lost by evaporation). Slightly increasing the efficiency by only 10-20% together with bringing additional water would cause a dramatic change in the farmer's life and in their income. A Pre-feasibility study indicates that there are deeper subsurface groundwater systems that flow from the Andes Mountain downstream to the valleys. The deeper systems are most probably separated from the spring systems. The deeper groundwater systems are flowing from the Andes Mountains downstream via individual paths, in places where both sides of the faults contain permeable layers and through several alluvial fans. Detailed researches are planned in the next few years to identify those individual sites and to locate sites for drilling boreholes (observation and production). Today, an integrated water resources management at the local and regional level is lacking. The feasibility studies will include recommendations to the regional government on how to implement such an integrated management program together with capacity building of the institutional capability of regional governments.

VARIABLE-THROW CAM

DOEpatents

Godsil, E.C.; Robinson, E.Y.

1963-07-16

A variable-throw cam comprising inner and outer eccentric sleeves which are adjustably locked together is described. The cam throw is varied by unlocking the inner and outer sleeves, rotating the outer sleeve relative to the inner one until the desired throw is obtained, and locking the sleeves together again. The cam is useful in applications wherein a continuously-variable throw is required, e.g., ram-and-die pressing operations, cyclic fatigue testing of materials, etc. (AEC)

Neotectonics of interior Alaska and the late Quaternary slip rate along the Denali fault system

USGS Publications Warehouse

Haeussler, Peter J.; Matmon, Ari; Schwartz, David P.; Seitz, Gordon G.

2017-01-01

The neotectonics of southern Alaska (USA) are characterized by a several hundred kilometers–wide zone of dextral transpressional that spans the Alaska Range. The Denali fault system is the largest active strike-slip fault system in interior Alaska, and it produced a Mw 7.9 earthquake in 2002. To evaluate the late Quaternary slip rate on the Denali fault system, we collected samples for cosmogenic surface exposure dating from surfaces offset by the fault system. This study includes data from 107 samples at 19 sites, including 7 sites we previously reported, as well as an estimated slip rate at another site. We utilize the interpreted surface ages to provide estimated slip rates. These new slip rate data confirm that the highest late Quaternary slip rate is ∼13 mm/yr on the central Denali fault near its intersection with the eastern Denali and the Totschunda faults, with decreasing slip rate both to the east and west. The slip rate decreases westward along the central and western parts of the Denali fault system to 5 mm/yr over a length of ∼575 km. An additional site on the eastern Denali fault near Kluane Lake, Yukon, implies a slip rate of ∼2 mm/yr, based on geological considerations. The Totschunda fault has a maximum slip rate of ∼9 mm/yr. The Denali fault system is transpressional and there are active thrust faults on both the north and south sides of it. We explore four geometric models for southern Alaska tectonics to explain the slip rates along the Denali fault system and the active fault geometries: rotation, indentation, extrusion, and a combination of the three. We conclude that all three end-member models have strengths and shortcomings, and a combination of rotation, indentation, and extrusion best explains the slip rate observations.

Elastic energy storage in the shoulder and the evolution of high-speed throwing in Homo

PubMed Central

Roach, Neil T.; Venkadesan, Madhusudhan; Rainbow, Michael J.; Lieberman, Daniel E.

2013-01-01

Although some primates, including chimpanzees, throw objects occasionally1,2, only humans regularly throw projectiles with high speed and great accuracy. Darwin noted that humans’ unique throwing abilities, made possible when bipedalism emancipated the arms, enabled foragers to effectively hunt using projectiles3. However, there has been little consideration of the evolution of throwing in the years since Darwin made his observations, in part because of a lack of evidence on when, how, and why hominins evolved the ability to generate high-speed throws4-8. Here, we show using experimental studies of throwers that human throwing capabilities largely result from several derived anatomical features that enable elastic energy storage and release at the shoulder. These features first appear together approximately two million years ago in the species Homo erectus. Given archaeological evidence that suggests hunting activity intensified around this time9, we conclude that selection for throwing in order to hunt likely played an important role in the evolution of the human genus. PMID:23803849

Analysis of the influence of the milling machine throw-out plate surfacing and structure design on throwing material

NASA Astrophysics Data System (ADS)

Fang, Yuanbin; Sha, Hongwei; Yu, Yunmin; Chen, Bing

2018-03-01

Material composition, hardness and wear properties of the throw-out plate improved are analysed on a road milling machine. At the same time, analyse the tissue and performance of Fe based alloy named Fe60 cladding layer using the plasma surfacing method. And the original and improved throw-out plates are analysed throwing material effect by the dynamic analysis. Then the throw-out plate samples are verified. The results show that Fe60 powder is selected as surface strengthening material. By the improved structure, the hardness of the throw-out plate increases from 14.6HRC to 57.5HRC, and the wear resistance increases from 0.452g-1 to 16.393g-1. At the same time, it increases from 3263 to 3433 to fall into the collecting material number of milling machine. It provides important guidance for structure design and process design of the milling machine throw-out plate.

Throwing speed and accuracy in baseball and cricket players.

PubMed

Freeston, Jonathan; Rooney, Kieron

2014-06-01

Throwing speed and accuracy are both critical to sports performance but cannot be optimized simultaneously. This speed-accuracy trade-off (SATO) is evident across a number of throwing groups but remains poorly understood. The goal was to describe the SATO in baseball and cricket players and determine the speed that optimizes accuracy. 20 grade-level baseball and cricket players performed 10 throws at 80% and 100% of maximal throwing speed (MTS) toward a cricket stump. Baseball players then performed a further 10 throws at 70%, 80%, 90%, and 100% of MTS toward a circular target. Baseball players threw faster with greater accuracy than cricket players at both speeds. Both groups demonstrated a significant SATO as vertical error increased with increases in speed; the trade-off was worse for cricketers than baseball players. Accuracy was optimized at 70% of MTS for baseballers. Throwing athletes should decrease speed when accuracy is critical. Cricket players could adopt baseball-training practices to improve throwing performance.

Fault connectivity, distributed shortening, and impacts on geologic- geodetic slip rate discrepancies in the central Mojave Desert, California

NASA Astrophysics Data System (ADS)

Selander, J.; Oskin, M. E.; Cooke, M. L.; Grette, K.

2015-12-01

Understanding off-fault deformation and distribution of displacement rates associated with disconnected strike-slip faults requires a three-dimensional view of fault geometries. We address problems associated with distributed faulting by studying the Mojave segment of the East California Shear Zone (ECSZ), a region dominated by northwest-directed dextral shear along disconnected northwest- southeast striking faults. We use a combination of cross-sectional interpretations, 3D Boundary Element Method (BEM) models, and slip-rate measurements to test new hypothesized fault connections. We find that reverse faulting acts as an important means of slip transfer between strike-slip faults, and show that the impacts of these structural connections on shortening, uplift, strike-slip rates, and off-fault deformation, help to reconcile the overall strain budget across this portion of the ECSZ. In detail, we focus on the Calico and Blackwater faults, which are hypothesized to together represent the longest linked fault system in the Mojave ECSZ, connected by a restraining step at 35°N. Across this restraining step the system displays a pronounced displacement gradient, where dextral offset decreases from ~11.5 to <2 km from south to north. Cross-section interpretations show that ~40% of this displacement is transferred from the Calico fault to the Harper Lake and Blackwater faults via a set of north-dipping thrust ramps. Late Quaternary dextral slip rates follow a similar pattern, where 1.4 +0.8/-0.4 mm/yr of slip along the Calico fault south of 35°N is distributed to the Harper Lake, Blackwater, and Tin Can Alley faults. BEM model results using revised fault geometries for the Mojave ECSZ show areas of uplift consistent with contractional structures, and fault slip-rates that more closely match geologic data. Overall, revised fault connections and addition of off-fault deformation greatly reduces the discrepancy between geodetic and geologic slip rates.

Extension across Tempe Terra, Mars, from measurements of fault scarp widths and deformed craters

USGS Publications Warehouse

Golombek, M.P.; Tanaka, K.L.; Franklin, B.J.

1996-01-01

Two independent methods, with no common assumptions, have been used to estimate the extension across the heavily deformed Tempe Terra province of the Tharsis region of Mars. One method uses measurements of normal fault scarp width with average scarp slope data for simple grabens and rifts on Mars to estimate the fault throw, which, combined with sparse fault dip data, can be used to estimate extension. Formal uncertainties in this method are only slightly greater than those in other methods, given that the total uncertainty is dominated by the likely uncertainty in the fault dip (assumed to be 60????15??). Measurement of normal fault scarp widths along two N25??-50??W directed traverses across Tempe Terra both yield about 22??16 km of extension (or ???2% strain across the northern traverse and nearly 3% across the southern one). About three quarters of the extension has occurred during the two main phases of Tharsis-related deformation from Middle/Late Noachian to Early Hesperian and from Late Hesperian to Early Amazonian, with more extension closer to the center of Tharsis during the first phase. Extension across the region was also determined by measuring the elongation and elongation direction of all ancient Noachian impact craters without ejecta blankets, which predate most of the deformation. Results have been corrected for initial non circularity of craters, established from similar measurements of young (post deformation) impact craters, yielding a statistically significant mean strain of 1.96??0.35% in a N38????10??W direction across Tempe Terra (extension of ???20??4, comparable in magnitude and direction to the average result from the scarp measurement method). Both methods indicate an average extension for single normal fault scarps (and shortening across wrinkle ridges for the crater method) of ???100 m. The agreement between the results of the two independent methods in overall extension and average single normal fault extension argues that the average scarp slope and fault dip data in the fault scarp width method accurately represent the actual extension across the observed structures. This conclusion supports existing geometric and kinematic models for structural features on Mars. A preliminary estimate of the total circumferential extension around Tharsis (at a radius of ???2500 km) is roughly 60??42 km; total hoop strain is about 0.4% distributed heterogeneously (Tempe Terra is the most highly strained region on Mars). Copyright 1997 by the American Geophysical Union.

Extension across Tempe Terra, Mars, from measurements of fault scarp widths and deformed craters

NASA Astrophysics Data System (ADS)

Golombek, M. P.; Tanaka, K. L.; Franklin, B. J.

Two independent methods, with no common assumptions, have been used to estimate the extension across the heavily deformed Tempe Terra province of the Tharsis region of Mars. One method uses measurements of normal fault scarp width with average scarp slope data for simple grabens and rifts on Mars to estimate the fault throw, which, combined with sparse fault dip data, can be used to estimate extension. Formal uncertainties in this method are only slightly greater than those in other methods, given that the total uncertainty is dominated by the likely uncertainty in the fault dip (assumed to be 60°+/-15°). Measurement of normal fault scarp widths along two N25°-50°W directed traverses across Tempe Terra both yield about 22+/-16 km of extension (or ~2% strain across the northern traverse and nearly 3% across the southern one). About three quarters of the extension has occurred during the two main phases of Tharsis-related deformation from Middle/Late Noachian to Early Hesperian and from Late Hesperian to Early Amazonian, with more extension closer to the center of Tharsis during the first phase. Extension across the region was also determined by measuring the elongation and elongation direction of all ancient Noachian impact craters without ejecta blankets, which predate most of the deformation. Results have been corrected for initial non circularity of craters, established from similar measurements of young (post deformation) impact craters, yielding a statistically significant mean strain of 1.96+/-0.35% in a N38°+/-10°W direction across Tempe Terra (extension of ~20+/-4, comparable in magnitude and direction to the average result from the scarp measurement method). Both methods indicate an average extension for single normal fault scarps (and shortening across wrinkle ridges for the crater method) of ~100 m. The agreement between the results of the two independent methods in overall extension and average single normal fault extension argues that the average scarp slope and fault dip data in the fault scarp width method accurately represent the actual extension across the observed structures. This conclusion supports existing geometric and kinematic models for structural features on Mars. A preliminary estimate of the total circumferential extension around Tharsis (at a radius of ~2500 km) is roughly 60+/-42 km; total hoop strain is about 0.4% distributed heterogeneously (Tempe Terra is the most highly strained region on Mars).

The Kinetic Chain Revisited: New Concepts on Throwing Mechanics and Injury.

PubMed

Chu, Samuel K; Jayabalan, Prakash; Kibler, W Ben; Press, Joel

2016-03-01

The overhead throwing motion is a complex activity that is achieved through activation of the kinetic chain. The kinetic chain refers to the linkage of multiple segments of the body that allows for transfer of forces and motion. The lower extremities and core provide a base of support, generating energy that is transferred eventually through the throwing arm and hand, resulting in release of the ball. The kinetic chain requires optimal anatomy, physiology, and mechanics and is involved in all 6 phases of overhead throwing: windup, stride, arm cocking, acceleration, deceleration, and follow-through. Breaks or deficits in the kinetic chain can lead to injury or decreased performance. Through an understanding of the mechanics and pathomechanics seen in each phase of throwing, the clinician can better evaluate and screen for potential kinetic chain deficits in the overhead throwing athlete. The purpose of this article is to review the biomechanics of the overhead throwing motion, the role of the kinetic chain in throwing, and the clinical evaluation and management of abnormal throwing mechanics and related injuries. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Hand preference for sending mobile-phone text messages: associations with sex, writing hand, and throwing hand.

PubMed

Lambert, Anthony; Hallett, Charlene

2009-07-01

Hand preference for sending mobile-phone text messages ("texting") and its relationship with hand preference for other activities were investigated in a questionnaire study with 886 participants. Overall rates of both sinistrality and dextrality were reduced for texting, in comparison with other activities, due to the substantial number of individuals who use both hands simultaneously when performing this activity. Because they both involve verbal expression, it was hypothesised that the association between hand preferences for texting and writing might be stronger than the association between either of these tasks and more spatial activities, such as throwing. This prediction was not confirmed, either in the sample as a whole or in a sub-group of individuals who reported writing and throwing with opposite hands. Females were less likely than males to use their left hand when sending text messages. Implications of these findings are discussed, in relation to theoretical views of handedness and in relation to practical aspects of mobile-phone design.

Fault Specific Seismic Hazard Maps as Input to Loss Reserves Calculation for Attica Buildings

NASA Astrophysics Data System (ADS)

Deligiannakis, Georgios; Papanikolaou, Ioannis; Zimbidis, Alexandros; Roberts, Gerald

2014-05-01

Greece is prone to various natural disasters, such as wildfires, floods, landslides and earthquakes, due to the special environmental and geological conditions dominating in tectonic plate boundaries. Seismic is the predominant risk, in terms of damages and casualties in the Greek territory. The historical record of earthquakes in Greece has been published from various researchers, providing useful data in seismic hazard assessment of Greece. However, the completeness of the historical record in Greece, despite being one of the longest worldwide, reaches only 500 years for M ≥ 7.3 and less than 200 years for M ≥ 6.5. Considering that active faults in the area have recurrence intervals of a few hundred to several thousands of years, it is clear that many active faults have not been activated during the completeness period covered by the historical records. New Seismic Hazard Assessment methodologies tend to follow fault specific approaches where seismic sources are geologically constrained active faults, in order to address problems related to the historical records incompleteness, obtain higher spatial resolution and calculate realistic source locality distances, since seismic sources are very accurately located. Fault specific approaches provide quantitative assessments as they measure fault slip rates from geological data, providing a more reliable estimate of seismic hazard. We used a fault specific seismic hazard assessment approach for the region of Attica. The method of seismic hazard mapping from geological fault throw-rate data combined three major factors: Empirical data which combine fault rupture lengths, earthquake magnitudes and coseismic slip relationships. The radiuses of VI, VII, VIII and IX isoseismals on the Modified Mercalli (MM) intensity scale. Attenuation - amplification functions for seismic shaking on bedrock compared to basin filling sediments. We explicitly modeled 22 active faults that could affect the region of Attica, including Athens, using detailed data derived from published papers, neotectonic maps and fieldwork observations. Moreover, we incorporated background seismicity models from the historic record and also the subduction zone earthquakes distribution, for the integration of strong deep earthquakes that could also affect Attica region. We created 4 high spatial resolution seismic hazard maps for the region of Attica, one for each of the intensities VII - X (MM). These maps offer a locality specific shaking recurrence record, which represents the long-term shaking record in a more complete way, since they incorporate several seismic cycles of the active faults that could affect Attica. Each one of these high resolution seismic hazard maps displays both the spatial distribution and the recurrence, over a specific time period, of the relevant intensity. Time - independent probabilities were extracted based on these average recurrence intervals, using the stationary Poisson model P = 1 -e-Λt. The 'Λ' value was provided by the intensities recurrence, as displayed in the seismic hazard maps. However, the insurance contracts usually lack of detailed spatial information and they refer to Postal Codes level, akin to CRESTA zones. To this end, a time-independent probability of shaking at intensities VII - X was calculated for every Postal Code, for a given time period, using the Poisson model. The reserves calculation on buildings portfolio combines the probability of events of specific intensities within the Postal Codes, with the buildings characteristics, such as the building construction type and the insured value. We propose a standard approach for the reserves calculation K(t) for a specific time period: K (t) = x2 ·[x1 ·y1 ·P1(t) + x1 ·y2 ·P2(t) + x1 ·y3 ·P3(t) + x1 ·y4 ·P4(t)] x1 which is a function of the probabilities of occurrence for the seismic intensities VII - X (P1(t) -P4(t)) for the same period, the value of the building x1, the insured value x2 and the characteristics of the building, such as the construction type, age, height and use of property (y1 - y4). Furthermore a stochastic approach is also adopted in order to obtain the relevant reserve value K(t) for the specific time period. This calculation considers a set of simulations from the Poisson random variable and then taking the respective expectations.

30 CFR 57.9308 - Switch throws.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Switch throws. 57.9308 Section 57.9308 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND....9308 Switch throws. Switch throws shall be installed to provide clearance to protect switchmen from...

30 CFR 57.9308 - Switch throws.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Switch throws. 57.9308 Section 57.9308 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND....9308 Switch throws. Switch throws shall be installed to provide clearance to protect switchmen from...

30 CFR 56.9308 - Switch throws.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Switch throws. 56.9308 Section 56.9308 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Switch throws. Switch throws shall be installed to provide clearance to protect switchmen from contact...

30 CFR 57.9308 - Switch throws.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Switch throws. 57.9308 Section 57.9308 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND....9308 Switch throws. Switch throws shall be installed to provide clearance to protect switchmen from...

30 CFR 57.9308 - Switch throws.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Switch throws. 57.9308 Section 57.9308 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND....9308 Switch throws. Switch throws shall be installed to provide clearance to protect switchmen from...

30 CFR 56.9308 - Switch throws.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Switch throws. 56.9308 Section 56.9308 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Switch throws. Switch throws shall be installed to provide clearance to protect switchmen from contact...

30 CFR 56.9308 - Switch throws.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Switch throws. 56.9308 Section 56.9308 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Switch throws. Switch throws shall be installed to provide clearance to protect switchmen from contact...

30 CFR 56.9308 - Switch throws.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Switch throws. 56.9308 Section 56.9308 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Switch throws. Switch throws shall be installed to provide clearance to protect switchmen from contact...

30 CFR 56.9308 - Switch throws.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Switch throws. 56.9308 Section 56.9308 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Switch throws. Switch throws shall be installed to provide clearance to protect switchmen from contact...

Throwing, the Shoulder, and Human Evolution.

PubMed

Kuhn, John E

2016-01-01

Throwing with accuracy and speed is a skill unique to humans. Throwing has many advantages and the ability to throw has likely been promoted through natural selection in the evolution of humans. There are many unsolved questions regarding the anatomy of the human shoulder. The purpose of this article is to review many of these mysteries and propose that the answer to these questions can be understood if one views the shoulder as a joint that has evolved to throw.

The Lewis thrust fault and related structures in the Disturbed Belt, northwestern Montana

USGS Publications Warehouse

Mudge, Melville Rhodes; Earhart, Robert L.

1980-01-01

The classical Lewis thrust fault in Glacier National Park has now been mapped 125 km south of the park to Steamboat Mountain, where the trace dies out in folded middle Paleozoic rocks. The known length of the fault is 452 km, extending northward from Steamboat Mountain to a point 225 km into Canada, where the fault also dies out in Paleozoic rocks. At the south end, the surface expression of the Lewis thrust begins in a shear zone in folded Mississippian rocks. To the north, the thrust progressively cuts downsection into Proterozoic Y (Belt) rocks near Glacier National Park. Displacement on the Lewis plate increases northward from approximately 3 km on an easterly trending hinge line at the West Fork of the Sun River to a postulated 65 km at the southern edge of the park, where the stratigraphic throw is about 6,500 m. Present data indicate the thrust formed during very late Paleocene to very early Eocene time. The Lewis thrust and related structures, the Hoadley thrust and the Continental Divide syncline, probably formed concurrently under the same stress field. The northern limit of the trace of the Hoadley thrust is within the lower portion of the Lewis plate, about 28 km north of where the Lewis thrust develops, and the Hoadley extends for at least 125 km to the south. Displacement of the Hoadley increases southward from about 1 km at the hinge line to an inferred 70 km near its known southern extent. If our inference is correct, the Hoadley is nearly the southern mirror image of the Lewis to the north. The Continental Divide syncline, a doubly plunging, broad, northerly trending open fold that is about 120 km long, is a major fold within the Lewis plate.

Paleomagnetic and structural evidence for oblique slip in a fault-related fold, Grayback monocline, Colorado

USGS Publications Warehouse

Tetreault, J.; Jones, C.H.; Erslev, E.; Larson, S.; Hudson, M.; Holdaway, S.

2008-01-01

Significant fold-axis-parallel slip is accommodated in the folded strata of the Grayback monocline, northeastern Front Range, Colorado, without visible large strike-slip displacement on the fold surface. In many cases, oblique-slip deformation is partitioned; fold-axis-normal slip is accommodated within folds, and fold-axis-parallel slip is resolved onto adjacent strike-slip faults. Unlike partitioning strike-parallel slip onto adjacent strike-slip faults, fold-axis-parallel slip has deformed the forelimb of the Grayback monocline. Mean compressive paleostress orientations in the forelimb are deflected 15??-37?? clockwise from the regional paleostress orientation of the northeastern Front Range. Paleomagnetic directions from the Permian Ingleside Formation in the forelimb are rotated 16??-42?? clockwise about a bedding-normal axis relative to the North American Permian reference direction. The paleostress and paleomagnetic rotations increase with the bedding dip angle and decrease along strike toward the fold tip. These measurements allow for 50-120 m of fold-axis-parallel slip within the forelimb, depending on the kinematics of strike-slip shear. This resolved horizontal slip is nearly equal in magnitude to the ???180 m vertical throw across the fold. For 200 m of oblique-slip displacement (120 m of strike slip and 180 m of reverse slip), the true shortening direction across the fold is N90??E, indistinguishable from the regionally inferred direction of N90??E and quite different from the S53??E fold-normal direction. Recognition of this deformational style means that significant amounts of strike slip can be accommodated within folds without axis-parallel surficial faulting. ?? 2008 Geological Society of America.

Rare normal faulting earthquake induced by subduction megaquake: example from 2011 Tohoku-oki earthquake

NASA Astrophysics Data System (ADS)

Ishiyama, T.; Sugito, N.; Echigo, T.; Sato, H.; Suzuki, T.

2012-04-01

A month after March 11 gigantic M9.0 Tohoku-oki earthquake, M7.0 intraplate earthquake occurred at a depth of 5 km on April 11 beneath coastal area of near Iwaki city, Fukushima prefecture. Focal mechanism of the mainshock indicates that this earthquake is a normal faulting event. Based on field reconnaissance and LIDAR mapping by Geospatial Information Authority of Japan, we recognized coseismic surface ruptures, presumably associated with the main shock. Coseismic surface ruptures extend NNW for about 11 km in a right-stepping en echelon manner. Geomorphic expressions of these ruptures commonly include WWS-facing normal fault scarps and/or drape fold scarp with open cracks on their crests, on the hanging wall sides of steeply west-dipping normal fault planes subparallel to Cretaceous metamorphic rocks. Highest topographic scarp height is about 2.3 m. In this study we introduce preliminary results of a trenching survey across the coseismic surface ruptures at Shionohira site, to resolve timing of paleoseismic events along the Shionohira fault. Trench excavations were carried out at two sites (Ichinokura and Shionohira sites) in Iwaki, Fukushima. At Shionohira site a 2-m-deep trench was excavated across the coseismic fault scarp emerged on the alluvial plain on the eastern flank of the Abukuma Mountains. On the trench walls we observed pairs of steeply dipping normal faults that deform Neogene to Paleogene conglomerates and unconformably overlying, late Quaternary to Holocene fluvial units. Sense of fault slip observed on the trench walls (large dip-slip with small sinistral component) is consistent with that estimated from coseismic surface ruptures. Fault throw estimated from separation of piercing points on lower Unit I and vertical structural relief on folded upper Unit I is consistent with topographic height of the coseismic fault scarp at the trench site. In contrast, vertical separation of Unit II, unconformably overlain by Unit I, is measured as about 1.5 m, twice as large as coseismic vertical component of slip, indicative of penultimate seismic event prior to the 2011 earthquake. Abrupt thickening of overlying Unit I may also suggest preexisting topographic relief prior to its deposition. Radiocarbon dating of charred materials included in event horizons and tephrostratigraphy at two sites indicate that penultimate event prior to the 2011 event might occurred at about 40 ka. This normal fault earthquake is in contrast to compressional or neutral stress regimes in Tohoku region before the 2011 megaquake and rarity of the normal faulting earthquake inferred from these paleoseismic studies may reflect its mechanical relation to the gigantic megathrust earthquakes, such as unusual, enhanced extensional stress on the hangingwall block induced by mainshock and/or postseismic creep after the M~9 earthquake.

46 CFR 108.597 - Line-throwing appliance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Line-throwing appliance. 108.597 Section 108.597... AND EQUIPMENT Lifesaving Equipment § 108.597 Line-throwing appliance. (a) General. Each unit in international service must have a line-throwing appliance that is approved under approval series 160.040. Each...

The Death Throes of Ocean Core Complexes: Examples from the Mid-Cayman Spreading Centre

NASA Astrophysics Data System (ADS)

Cheadle, M. J.; John, B. E.; German, C. R.; Kusznir, N. J.

2012-12-01

The Mid-Cayman Spreading Centre (MCSC) is an ultraslow (full rate 15-17 mm/yr) mid-ocean ridge that is located within the Cayman Trough, at the boundary between the North American and Caribbean plates. It is 110km long, and at ~6km below sea level, is the deepest spreading centre in the world. In the Summer of 2011, during NOAA EX 1104, the RV Okeanos Explorer collected high resolution (50m) Simrad EM302 multibeam bathymetry, and high-resolution video using the ROV Little Hercules ,which together provide insight into the evolution (from birth to death) of oceanic core complexes (OCCs). The MCSC exhibits bathymetry typical of slow spreading, magmatically deficient, ridges with thick lithosphere. It has both well-developed OCCs with ~15km of detachment fault offset and smaller offset (6-7km) normal faults forming >40km long linear ridges. Mass wasting is conspicuous. The MCSC is flanked on both sides by three oceanic core complexes: i) the now inactive, Mount Emms to the northeast, ii) the near-recently active Mount Dent in the west centre of the axial valley, and iii) the decapitated Mount Hudson on the south east flank. Together these massifs show different stages of OCC termination. Mount Emms lies approximately 2Ma off axis, is the oldest of the OCCs, and is heavily dissected by faulting and mass wasting. Mount Hudson is terminated by a west dipping high angle normal fault, with 1.6km throw and was initially rifted apart ~0.5Ma. A recently active axial volcanic ridge (AVR) with ROV observed pahoehoe lava forms, and a line of conical volcanic edifices lie within the rifted remains at the toe of the OCC. In contrast, Mount Dent was the most recently active, but is now in the very initial stages of being rifted apart by the presently active AVR that currently intersects the OCC. Incipient high angle normal faults that lie along strike of the AVR cut the dome of Mount Dent, and host the active von Damm hydrothermal system. Mount Dent also shows excess (>1km) uplift beyond that expected by simple flexural uplift, in contrast to the ridges bounded by the smaller offset (6-7km) normal faults, which can be explained by flexural uplift. Together these three OCCs adjacent to the MCSC highlight two interacting processes that lead to OCC termination. Firstly asymmetric spreading associated with OCC development leads to the root of the bounding detachment fault migrating across the axial valley. Secondly, migration of the locus of magmatism can lead to the AVR intersecting the OCC. Both of these processes ultimately lead to rifting and hence termination of the OCC. We suggest that the anomalous uplift of Mount Dent might be an initial response to increased magmatic activity beneath the OCC, and that continued magmatic activity led to thermal weakening of the lithosphere, with development of normal faults and rifting within the dome of the OCC. Interestingly, one key outcome of this new interpretation of the Mt Dent OCC is that the Von Damm hydrothermal field becomes an on-axis vent system.

Reconnaissance study of late quaternary faulting along cerro GoDen fault zone, western Puerto Rico

USGS Publications Warehouse

Mann, P.; Prentice, C.S.; Hippolyte, J.-C.; Grindlay, N.R.; Abrams, L.J.; Lao-Davila, D.

2005-01-01

The Cerro GoDen fault zone is associated with a curvilinear, continuous, and prominent topographic lineament in western Puerto Rico. The fault varies in strike from northwest to west. In its westernmost section, the fault is ???500 m south of an abrupt, curvilinear mountain front separating the 270- to 361-m-high La CaDena De San Francisco range from the Rio A??asco alluvial valley. The Quaternary fault of the A??asco Valley is in alignment with the bedrock fault mapped by D. McIntyre (1971) in the Central La Plata quadrangle sheet east of A??asco Valley. Previous workers have postulated that the Cerro GoDen fault zone continues southeast from the A??asco Valley and merges with the Great Southern Puerto Rico fault zone of south-central Puerto Rico. West of the A??asco Valley, the fault continues offshore into the Mona Passage (Caribbean Sea) where it is characterized by offsets of seafloor sediments estimated to be of late Quaternary age. Using both 1:18,500 scale air photographs taken in 1936 and 1:40,000 scale photographs taken by the U.S. Department of Agriculture in 1986, we iDentified geomorphic features suggestive of Quaternary fault movement in the A??asco Valley, including aligned and Deflected drainages, apparently offset terrace risers, and mountain-facing scarps. Many of these features suggest right-lateral displacement. Mapping of Paleogene bedrock units in the uplifted La CaDena range adjacent to the Cerro GoDen fault zone reveals the main tectonic events that have culminated in late Quaternary normal-oblique displacement across the Cerro GoDen fault. Cretaceous to Eocene rocks of the La CaDena range exhibit large folds with wavelengths of several kms. The orientation of folds and analysis of fault striations within the folds indicate that the folds formed by northeast-southwest shorTening in present-day geographic coordinates. The age of Deformation is well constrained as late Eocene-early Oligocene by an angular unconformity separating folDed, Deep-marine middle Eocene rocks from transgressive, shallow-marine rocks of middle-upper Oligocene age. Rocks of middle Oligocene-early Pliocene age above unconformity are gently folDed about the roughly east-west-trending Puerto Rico-Virgin Islands arch, which is well expressed in the geomorphology of western Puerto Rico. Arching appears ongoing because onshore and offshore late Quaternary oblique-slip faults closely parallel the complexly Deformed crest of the arch and appear to be related to exTensional strains focused in the crest of the arch. We estimate ???4 km of vertical throw on the Cerro GoDen fault based on the position of the carbonate cap north of the fault in the La CaDena De San Francisco and its position south of the fault inferred from seismic reflection data in Mayaguez Bay. Based on these observations, our interpretation of the kinematics and history of the Cerro GoDen fault zone incluDes two major phases of motion: (1) Eocene northeast-southwest shorTening possibly accompanied by left-lateral shearing as Determined by previous workers on the Great Southern Puerto Rico fault zone; and (2) post-early Pliocene regional arching of Puerto Rico accompanied by normal offset and right-lateral shear along faults flanking the crest of the arch. The second phase of Deformation accompanied east-west opening of the Mona rift and is inferred to continue to the present day. ?? 2005 Geological Society of America.

Spatiotemporal Patterns of Fault Slip Rates Across the Central Sierra Nevada Frontal Fault Zone

NASA Astrophysics Data System (ADS)

Rood, D. H.; Burbank, D.; Finkel, R. C.

2010-12-01

We examine patterns in fault slip rates through time and space across the transition from the Sierra Nevada to the Eastern California Shear Zone-Walker Lane belt. At each of four sites along the eastern Sierra Nevada frontal fault zone between 38-39° N latitude, geomorphic markers, such as glacial moraines and outwash terraces, are displaced by a suite of range-front normal faults. Using geomorphic mapping, surveying, and Be-10 surface exposure dating, we define mean fault slip rates, and by utilizing markers of different ages (generally, ~20 ka and ~150 ka), we examine rates through time and interactions among multiple faults over 10-100 ky timescales. At each site for which data are available for the last ~150 ky, mean slip rates across the Sierra Nevada frontal fault zone have probably not varied by more than a factor of two over time spans equal to half of the total time interval (~20 ky and ~150 ky timescales): 0.3 ± 0.1 mm/yr (mode and 95% CI) at both Buckeye Creek in the Bridgeport basin and Sonora Junction; and 0.4 +0.3/-0.1 mm/yr along the West Fork of the Carson River at Woodfords. Our data permit that rates are relatively constant over the time scales examined. In contrast, slip rates are highly variable in space over the last ~20 ky. Slip rates decrease by a factor of 3-5 northward over a distance of ~20 km between the northern Mono Basin (1.3 +0.6/-0.3 mm/yr at Lundy Canyon site) and the Bridgeport Basin (0.3 ± 0.1 mm/yr). The 3-fold decrease in the slip rate on the Sierra Nevada frontal fault zone northward from Mono Basin reflects a change in the character of faulting north of the Mina Deflection as extension is transferred eastward onto normal faults between the Sierra Nevada and Walker Lane belt. A compilation of regional deformation rates reveal that the spatial pattern of extension rates changes along strike of the Eastern California Shear Zone-Walker Lane belt. South of the Mina Deflection, extension is accommodated within a diffuse zone of normal and oblique faults, with extension rates increasing northward on the Fish Lake Valley fault. Where faults of the Eastern California Shear Zone terminate northward into the Mina Deflection, extension rates increase northward along the Sierra Nevada frontal fault zone to ~0.7 mm/yr in northern Mono Basin. This spatial pattern suggests that extension is transferred from faults systems to the east (e.g. Fish Lake Valley fault) and localized on the Sierra Nevada frontal fault zone as Eastern California Shear Zone-Walker Lane belt faulting is transferred through the Mina Deflection.

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.

46 CFR 133.170 - Line-throwing appliance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Line-throwing appliance. 133.170 Section 133.170... SYSTEMS Requirements for All OSVs § 133.170 Line-throwing appliance. (a) General. Each OSV must have a line-throwing appliance that is approved under approval series 160.031 or 160.040. (b) Stowage. The...

Throwing velocities, anthropometric characteristics, and efficacy indices of women's European water polo subchampions.

PubMed

Alcaraz, Pedro E; Abraldes, J Arturo; Ferragut, Carmen; Rodríguez, Nuria; Argudo, Francisco M; Vila, Helena

2011-11-01

Water polo is a team sport characterized by a high-intensity, intermittent activity, where technical and tactical aspect are of a great importance. For that reason, the main aim of this study was to define the anthropometrical characteristics, maximum isometric grip strength, training and competition throwing velocities, and the efficacy indices in female high-level water polo players. A second purpose was to examine the differences between the throwing velocities in training vs. European championships in the water polo female national team. Ten elite trained female water polo players participated in this study. Before the competitive phase of their season, the following measures were taken: standard anthropometry, static and dynamic training throwing velocities, and hand-grip dynamometry. In the competitive phase, efficacy indices, average and maximum throwing velocities from all the participants were also determined. Significant differences (p ≤ 0.05) were found between different training situations and different competitive throwing velocities. We concluded that elite female water polo players modify their throwing velocity depending if the throw is performed during training or competitive situation.

Using surface creep rate to infer fraction locked for sections of the San Andreas fault system in northern California from alignment array and GPS data

USGS Publications Warehouse

Lienkaemper, James J.; McFarland, Forrest S.; Simpson, Robert W.; Caskey, S. John

2014-01-01

Surface creep rate, observed along five branches of the dextral San Andreas fault system in northern California, varies considerably from one section to the next, indicating that so too may the depth at which the faults are locked. We model locking on 29 fault sections using each section’s mean long‐term creep rate and the consensus values of fault width and geologic slip rate. Surface creep rate observations from 111 short‐range alignment and trilateration arrays and 48 near‐fault, Global Positioning System station pairs are used to estimate depth of creep, assuming an elastic half‐space model and adjusting depth of creep iteratively by trial and error to match the creep observations along fault sections. Fault sections are delineated either by geometric discontinuities between them or by distinctly different creeping behaviors. We remove transient rate changes associated with five large (M≥5.5) regional earthquakes. Estimates of fraction locked, the ratio of moment accumulation rate to loading rate, on each section of the fault system provide a uniform means to inform source parameters relevant to seismic‐hazard assessment. From its mean creep rates, we infer the main branch (the San Andreas fault) ranges from only 20%±10% locked on its central creeping section to 99%–100% on the north coast. From mean accumulation rates, we infer that four urban faults appear to have accumulated enough seismic moment to produce major earthquakes: the northern Calaveras (M 6.8), Hayward (M 6.8), Rodgers Creek (M 7.1), and Green Valley (M 7.1). The latter three faults are nearing or past their mean recurrence interval.

Comparison of range of motion tests with throwing kinematics in elite team handball players.

PubMed

van den Tillaar, Roland

2016-10-01

The aim of this study was to compare the active and passive range of motion (ROM) of the glenohumeral external rotation with the maximal external rotation and throwing performance during different throws with different wind-up techniques in elite team handball players. Twenty-two elite team handball players participated in the study in which the maximal ball release velocity and maximal external rotation during standing, with run-up and jump throws with two types of wind-ups were measured together with the maximal active and passive glenohumeral ROM of the external rotation, lying supine on a bench. Higher maximal external rotation was found during the throws with the whip-like wind-up in comparison to circular-like wind-up throws together with a lower external rotation during the active ROM test. No correlations were found between the ROM of the external rotation with the maximal ball release velocity and the maximal external rotation measured during the throws. It was concluded that ROM of the external rotation measured on the bench does not give any information about the maximal throwing performance or the external rotation angle during throwing and therefore cannot be used to identify potential fast throwers or injuries in elite team handball players.

Comparing performance and kinematics of throwing with a circular and whip-like wind up by experienced handball players.

PubMed

van den Tillaar, R; Zondag, A; Cabri, J

2013-12-01

The aim of this study was to compare the performance (throwing velocity of the ball) and kinematics of overarm throwing with the circular and whip-like wind up in elite handball players. Twenty-two elite handball players (11 men and 11 women) conducted both types of throws. The ball release velocity, maximal ball acceleration, maximal velocity of the end points of the five segments and maximal angles, angles at ball release and maximal angular velocities of the 11 joint movements and their timing during the throw were analyzed. Significantly higher ball release velocities (21.9 m/s vs 20.6 m/s) were reached together with higher maximal linear velocities of the end points of all segments and longer throwing time with the circular wind up than with the whip-like wind up. Furthermore, it seems that the timing and amount of maximal angular pelvis rotation was the main contributor to the difference in the maximal ball release velocity between the two wind ups. The findings support the observation that overarm throwing with the circular wind up results in higher ball releases but also a longer throwing movement in comparison to whip-like wind up throws. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of stride length on overarm throwing delivery: A linear momentum response.

PubMed

Ramsey, Dan K; Crotin, Ryan L; White, Scott

2014-12-01

Changing stride length during overhand throwing delivery is thought to alter total body and throwing arm linear momentums, thereby altering the proportion of throwing arm momentum relative to the total body. Using a randomized cross-over design, nineteen pitchers (15 collegiate and 4 high school) were assigned to pitch two simulated 80-pitch games at ±25% of their desired stride length. An 8-camera motion capture system (240Hz) integrated with two force plates (960Hz) and radar gun tracked each throw. Segmental linear momentums in each plane of motion were summed yielding throwing arm and total body momentums, from which compensation ratio's (relative contribution between the two) were derived. Pairwise comparisons at hallmark events and phases identified significantly different linear momentum profiles, in particular, anteriorly directed total body, throwing arm, and momentum compensation ratios (P⩽.05) as a result of manipulating stride length. Pitchers with shorter strides generated lower forward (anterior) momentum before stride foot contact, whereas greater upward and lateral momentum (toward third base) were evident during the acceleration phase. The evidence suggests insufficient total body momentum in the intended throwing direction may potentially influence performance (velocity and accuracy) and perhaps precipitate throwing arm injuries. Copyright © 2014 Elsevier B.V. All rights reserved.

Neuromuscular and technical abilities related to age in water-polo players.

PubMed

De Siati, Fabio; Laffaye, Guillaume; Gatta, Giorgio; Dello Iacono, Antonio; Ardigò, Luca Paolo; Padulo, Johnny

2016-08-01

Testing is one of the important tasks in any multi-step sport programme. In most ball games, coaches assess motor, physical and technical skills on a regular basis in early stages of talent identification in order to further athletes' development. The purpose of the study was to investigate anthropometric variables and vertical jump heights as a free throw effectiveness predictor in water-polo players of different age groups. Two hundred and thirty-six young (10-18 years) male water-polo players partitioned into three age groups underwent anthropometric variables' measures and squat- and countermovement-jump tests, and performed water-polo free throws. Anthropometric variables, vertical jump heights and throw speed - as a proxy for free throw effectiveness - resulted different over age groups. Particularly, throw speed changed from 9.28 to 13.70 m · s(-1) (+48%) from younger to older players. A multiple-regression model indicated that body height, squat-jump height and throw time together explain 52% of variance of throw speed. In conclusion, tall height, high lower limb power and throwing quickness appeared to be relevant determinants for effective free throws. Such indications can help coaches during talent identification and development processes, even by means of novel training strategies. Further research is needed over different maturity statuses.

Methodology for earthquake rupture rate estimates of fault networks: example for the western Corinth rift, Greece

NASA Astrophysics Data System (ADS)

Chartier, Thomas; Scotti, Oona; Lyon-Caen, Hélène; Boiselet, Aurélien

2017-10-01

Modeling the seismic potential of active faults is a fundamental step of probabilistic seismic hazard assessment (PSHA). An accurate estimation of the rate of earthquakes on the faults is necessary in order to obtain the probability of exceedance of a given ground motion. Most PSHA studies consider faults as independent structures and neglect the possibility of multiple faults or fault segments rupturing simultaneously (fault-to-fault, FtF, ruptures). The Uniform California Earthquake Rupture Forecast version 3 (UCERF-3) model takes into account this possibility by considering a system-level approach rather than an individual-fault-level approach using the geological, seismological and geodetical information to invert the earthquake rates. In many places of the world seismological and geodetical information along fault networks is often not well constrained. There is therefore a need to propose a methodology relying on geological information alone to compute earthquake rates of the faults in the network. In the proposed methodology, a simple distance criteria is used to define FtF ruptures and consider single faults or FtF ruptures as an aleatory uncertainty, similarly to UCERF-3. Rates of earthquakes on faults are then computed following two constraints: the magnitude frequency distribution (MFD) of earthquakes in the fault system as a whole must follow an a priori chosen shape and the rate of earthquakes on each fault is determined by the specific slip rate of each segment depending on the possible FtF ruptures. The modeled earthquake rates are then compared to the available independent data (geodetical, seismological and paleoseismological data) in order to weight different hypothesis explored in a logic tree.The methodology is tested on the western Corinth rift (WCR), Greece, where recent advancements have been made in the understanding of the geological slip rates of the complex network of normal faults which are accommodating the ˜ 15 mm yr-1 north-south extension. Modeling results show that geological, seismological and paleoseismological rates of earthquakes cannot be reconciled with only single-fault-rupture scenarios and require hypothesizing a large spectrum of possible FtF rupture sets. In order to fit the imposed regional Gutenberg-Richter (GR) MFD target, some of the slip along certain faults needs to be accommodated either with interseismic creep or as post-seismic processes. Furthermore, computed individual faults' MFDs differ depending on the position of each fault in the system and the possible FtF ruptures associated with the fault. Finally, a comparison of modeled earthquake rupture rates with those deduced from the regional and local earthquake catalog statistics and local paleoseismological data indicates a better fit with the FtF rupture set constructed with a distance criteria based on 5 km rather than 3 km, suggesting a high connectivity of faults in the WCR fault system.

Throwing Accuracy

ERIC Educational Resources Information Center

Cross, Rod

2018-01-01

A simple throwing task is described to illustrate various aspects of projectile motion. The task was to throw a tennis ball in a waste paper bin about 2 m away. Success depends on skill, but it also depends on the physics of the problem. If the ball is thrown underarm, then success depends primarily on the throw speed, which must be controlled to…

Strain rate effect on fault slip and rupture evolution: Insight from meter-scale rock friction experiments

NASA Astrophysics Data System (ADS)

Xu, Shiqing; Fukuyama, Eiichi; Yamashita, Futoshi; Mizoguchi, Kazuo; Takizawa, Shigeru; Kawakata, Hironori

2018-05-01

We conduct meter-scale rock friction experiments to study strain rate effect on fault slip and rupture evolution. Two rock samples made of Indian metagabbro, with a nominal contact dimension of 1.5 m long and 0.1 m wide, are juxtaposed and loaded in a direct shear configuration to simulate the fault motion. A series of experimental tests, under constant loading rates ranging from 0.01 mm/s to 1 mm/s and under a fixed normal stress of 6.7 MPa, are performed to simulate conditions with changing strain rates. Load cells and displacement transducers are utilized to examine the macroscopic fault behavior, while high-density arrays of strain gauges close to the fault are used to investigate the local fault behavior. The observations show that the macroscopic peak strength, strength drop, and the rate of strength drop can increase with increasing loading rate. At the local scale, the observations reveal that slow loading rates favor generation of characteristic ruptures that always nucleate in the form of slow slip at about the same location. In contrast, fast loading rates can promote very abrupt rupture nucleation and along-strike scatter of hypocenter locations. At a given propagation distance, rupture speed tends to increase with increasing loading rate. We propose that a strain-rate-dependent fault fragmentation process can enhance the efficiency of fault healing during the stick period, which together with healing time controls the recovery of fault strength. In addition, a strain-rate-dependent weakening mechanism can be activated during the slip period, which together with strain energy selects the modes of fault slip and rupture propagation. The results help to understand the spectrum of fault slip and rock deformation modes in nature, and emphasize the role of heterogeneity in tuning fault behavior under different strain rates.

Throwing accuracy

NASA Astrophysics Data System (ADS)

Cross, Rod

2018-05-01

A simple throwing task is described to illustrate various aspects of projectile motion. The task was to throw a tennis ball in a waste paper bin about 2 m away. Success depends on skill, but it also depends on the physics of the problem. If the ball is thrown underarm, then success depends primarily on the throw speed, which must be controlled to within about 2%. The launch angle can be chosen within a wide range. If the ball is thrown overarm, then the launch angle is just as important as the throw speed.

Holocene deceleration of the San Andreas fault zone in San Bernardino and implications for the eastern California shear zone rate debate

NASA Astrophysics Data System (ADS)

Bennett, R. A.; Lavier, L.; Anderson, M. L.; Matti, J.; Powell, R. E.

2005-05-01

New geodetic inferences for the rate of strain accumulation on the San Andreas fault associated with tectonic loading are ~20 mm/yr slower than observed Holocene surface displacement rates in the San Bernardino area, south of the fault's intersection with the San Jacinto fault zone, and north of its intersection with the eastern California shear zone (ECSZ). This displacement rate "anomaly" is significantly larger than can be easily explained by locking depth errors or earthquake cycle effects not accounted for in geodesy-constrained models for elastic loading rate. Using available time-averaged fault displacement-rates for the San Andreas and San Jacinto fault zones, we estimate instantaneous time-variable displacement rates on the San Andreas-San Jacinto-ECSZ fault zones, assuming that these fault zones form a closed system in the latitude band along which the fault zones overlap with one another and share in the accommodation of steady Pacific-North America relative plate motion. We find that the Holocene decrease in San Andreas loading rate can be compensated by a rapid increase in loading/displacement rate within the ECSZ over the past ~5 kyrs, independent of, but consistent with geodetic and geologic constraints derived from the ECSZ itself. Based on this model, we suggest that reported differences between fast contemporary strain rates observed on faults of the ECSZ using geodesy and slow rates inferred from Quaternary geology and Holocene paleoseismology (i.e., the ECSZ rate debate) may be explained by rapid changes in the pattern and rates of strain accumulation associated with fault loading largely unrelated to postseismic stress relaxation. If so, displacement rate data sets from Holocene geology and present-day geodesy could potentially provide important new constraints on the rheology of the lower crust and upper mantle representing lithospheric behavior on time-scales of thousands of years. Moreover, the results underscore that disagreement between geodetic and geologic fault displacement rates may reflect changes in strain accumulation rates associated with far-field elastic loading and thus earthquake potential, and not just transients.

Evolving geometrical heterogeneities of fault trace data

NASA Astrophysics Data System (ADS)

Wechsler, Neta; Ben-Zion, Yehuda; Christofferson, Shari

2010-08-01

We perform a systematic comparative analysis of geometrical fault zone heterogeneities using derived measures from digitized fault maps that are not very sensitive to mapping resolution. We employ the digital GIS map of California faults (version 2.0) and analyse the surface traces of active strike-slip fault zones with evidence of Quaternary and historic movements. Each fault zone is broken into segments that are defined as a continuous length of fault bounded by changes of angle larger than 1°. Measurements of the orientations and lengths of fault zone segments are used to calculate the mean direction and misalignment of each fault zone from the local plate motion direction, and to define several quantities that represent the fault zone disorder. These include circular standard deviation and circular standard error of segments, orientation of long and short segments with respect to the mean direction, and normal separation distances of fault segments. We examine the correlations between various calculated parameters of fault zone disorder and the following three potential controlling variables: cumulative slip, slip rate and fault zone misalignment from the plate motion direction. The analysis indicates that the circular standard deviation and circular standard error of segments decrease overall with increasing cumulative slip and increasing slip rate of the fault zones. The results imply that the circular standard deviation and error, quantifying the range or dispersion in the data, provide effective measures of the fault zone disorder, and that the cumulative slip and slip rate (or more generally slip rate normalized by healing rate) represent the fault zone maturity. The fault zone misalignment from plate motion direction does not seem to play a major role in controlling the fault trace heterogeneities. The frequency-size statistics of fault segment lengths can be fitted well by an exponential function over the entire range of observations.

How fault evolution changes strain partitioning and fault slip rates in Southern California: Results from geodynamic modeling

NASA Astrophysics Data System (ADS)

Ye, Jiyang; Liu, Mian

2017-08-01

In Southern California, the Pacific-North America relative plate motion is accommodated by the complex southern San Andreas Fault system that includes many young faults (<2 Ma). The initiation of these young faults and their impact on strain partitioning and fault slip rates are important for understanding the evolution of this plate boundary zone and assessing earthquake hazard in Southern California. Using a three-dimensional viscoelastoplastic finite element model, we have investigated how this plate boundary fault system has evolved to accommodate the relative plate motion in Southern California. Our results show that when the plate boundary faults are not optimally configured to accommodate the relative plate motion, strain is localized in places where new faults would initiate to improve the mechanical efficiency of the fault system. In particular, the Eastern California Shear Zone, the San Jacinto Fault, the Elsinore Fault, and the offshore dextral faults all developed in places of highly localized strain. These younger faults compensate for the reduced fault slip on the San Andreas Fault proper because of the Big Bend, a major restraining bend. The evolution of the fault system changes the apportionment of fault slip rates over time, which may explain some of the slip rate discrepancy between geological and geodetic measurements in Southern California. For the present fault configuration, our model predicts localized strain in western Transverse Ranges and along the dextral faults across the Mojave Desert, where numerous damaging earthquakes occurred in recent years.

An overview of results from the CO2SINK 3D baseline seismic survey at Ketzin, Germany

NASA Astrophysics Data System (ADS)

Juhlin, C.; Giese, R.; Cosma, C.; Kazemeini, H.; Juhojuntti, N.; Lüth, S.; Norden, B.; Förster, A.; Yordkayhun, S.

2009-04-01

A 3D seismic survey was acquired at the CO2SINK project site over the Ketzin anticline in the fall of 2005. Main objectives of the survey were (1) to verify earlier geological interpretations of the structure based on vintage 2D seismic and borehole data, (2) to provide, if possible, an understanding of the structural geometry for flow pathways within the reservoir, (3) a baseline for later evaluation of the time evolution of rock properties as CO2 is injected into the reservoir, and (4) detailed sub-surface images near the injection borehole for planning of the drilling operations. Overlapping templates with 5 receiver lines containing 48 active channels in each template were used for the acquisition. In each template, 200 nominal source points were activated using an accelerated weight drop, giving a nominal fold of 25. Due to logistics, the number of actual source points in each template varied. In spite of the relatively low fold and the simple source used, data quality is generally good with the uppermost 1000 m being well imaged. Data processing results clearly show a fault system across the top of the Ketzin anticline that is termed the Central Graben Fault Zone (CGFZ). The fault zone consists of west-southwest-east-northeast- to east-west-trending normal faults bounding a 600-800 m wide graben. Within the Jurassic section, discrete faults are well developed, and the main graben-bounding faults have throws of up to 30 m. At shallower levels, the fault system appears to disappear in the Tertiary Rupelian clay. The main bounding faults of the CGFZ can be traced downwards to the top of the Weser Formation and possibly to the Stuttgart level, the target formation for CO2 injection. No faults were imaged near the injection site on the southern limb of the anticline. Remnant gas, cushion and residual gas from a previous natural gas storage facility at the site, is present near the top of the anticline in the depth interval of about 250-400 m and has a clear seismic signature. In addition to the standard processing and interpretation applied, attribute analysis, detailed shallow reflection seismic processing, tomographic inversion of first arrival times, and initial seismic modeling of the CO2 response have been performed. Attribute analysis of the target horizon using the continuous wavelet transform indicates that the injection site penetrates the target reservoir near the edge of a north-northwest-south-southeast striking channel.

Structure of a seismogenic fault zone in dolostones: the Foiana Line (Italian Southern Alps)

NASA Astrophysics Data System (ADS)

Di Toro, G.; Fondriest, M.; Smith, S. A.; Aretusini, S.

2012-12-01

Fault zones in carbonate rocks (limestones and dolostones) represent significant upper crustal seismogenic sources in several areas worldwide (e.g. L'Aquila 2009 Mw = 6.3 in central Italy). Here we describe an exhumed example of a regionally-significant fault zone cutting dolostones. The Foiana Line (FL) is a major NNE-SSW-trending sinistral transpressive fault cutting sedimentary Triassic dolostones in the Italian Southern Alps. The FL has a cumulative vertical throw of 1.5-2 km that reduces toward its southern termination. The fault zone is 50-300 m wide and is exposed for ~ 10 km along strike within several outcrops exhumed from increasing depths from the south (1 km) to the north (2.5 km). The southern portion of the FL consists of heavily fractured (shattered) dolostones, with particles of a few millimeters in size (exposed in badlands topography over an area of 6 km2), cut by a dense network of 1-20 m long mirror-like fault surfaces with dispersed attitudes. The mirror-like faults have mainly dip-slip reverse kinematics and displacements ranging between 0.04 m and 0.5 m. The northern portion of the FL consists of sub-parallel fault strands spaced 2-5 m apart, surrounded by 2-3 m thick bands of shattered dolostones. The fault strands are characterized by smooth to mirror-like sub-vertical slip surfaces with dominant strike-slip kinematics. Overall, deformation is more localized moving from South to North along the FL. Mirror-like fault surfaces similar to those found in the FL were produced in friction experiments at the deformation conditions expected during seismic slip along the FL (Fondriest et al., this meeting). Scanning Electron Microscope investigations of the natural shattered dolostones beneath the mirror-like fault surfaces show: 1) lack of significant shear strain (even at a few micrometers from the slip surface), 2) pervasive extensional fracturing down to the micrometer scale, 3) exploded clasts with radial fractures, and 4) chains of split clasts (resulting from force chains) oriented at 60-80 degrees to the slip surfaces. Similar features have been reported in natural and experimental pulverized rocks, the latter produced under dynamic stress wave loading conditions. 3-Dimensional rupture simulations along strike-slip faults predict (1) off-fault damage distributions with "flower-like" shapes (broad damage zone near the surface that rapidly narrows with increasing confining pressure, e.g., Ma and Andrews, 2010) and (2) formation of secondary faults/fractures with disperse attitudes and kinematics near the surface, with horizontal slip at depth. Qualitatively, these theoretical results compare favorably with increasing strain localization and a switch in fault kinematics recognized along the FL moving from the southern, shallower portion of the fault zone to the northern, deeper portion. Observations along the FL suggest that the association of shattered dolostones and mirror-like slip surfaces might be a potential indicator of seismic rupture propagation. Further detailed structural mapping along the FL coupled with experimental work on rock pulverization will be necessary to understand rupture dynamics in dolostones.

Predictive modelling of fault related fracturing in carbonate damage-zones: analytical and numerical models of field data (Central Apennines, Italy)

NASA Astrophysics Data System (ADS)

Mannino, Irene; Cianfarra, Paola; Salvini, Francesco

2010-05-01

Permeability in carbonates is strongly influenced by the presence of brittle deformation patterns, i.e pressure-solution surfaces, extensional fractures, and faults. Carbonate rocks achieve fracturing both during diagenesis and tectonic processes. Attitude, spatial distribution and connectivity of brittle deformation features rule the secondary permeability of carbonatic rocks and therefore the accumulation and the pathway of deep fluids (ground-water, hydrocarbon). This is particularly true in fault zones, where the damage zone and the fault core show different hydraulic properties from the pristine rock as well as between them. To improve the knowledge of fault architecture and faults hydraulic properties we study the brittle deformation patterns related to fault kinematics in carbonate successions. In particular we focussed on the damage-zone fracturing evolution. Fieldwork was performed in Meso-Cenozoic carbonate units of the Latium-Abruzzi Platform, Central Apennines, Italy. These units represent field analogues of rock reservoir in the Southern Apennines. We combine the study of rock physical characteristics of 22 faults and quantitative analyses of brittle deformation for the same faults, including bedding attitudes, fracturing type, attitudes, and spatial intensity distribution by using the dimension/spacing ratio, namely H/S ratio where H is the dimension of the fracture and S is the spacing between two analogous fractures of the same set. Statistical analyses of structural data (stereonets, contouring and H/S transect) were performed to infer a focussed, general algorithm that describes the expected intensity of fracturing process. The analytical model was fit to field measurements by a Montecarlo-convergent approach. This method proved a useful tool to quantify complex relations with a high number of variables. It creates a large sequence of possible solution parameters and results are compared with field data. For each item an error mean value is computed (RMS), representing the effectiveness of the fit and so the validity of this analysis. Eventually, the method selects the set of parameters that produced the least values. The tested algorithm describes the expected H/S values as a function of the distance from the fault core (D), the clay content (S), and the fault throw (T). The preliminary results of the Montecarlo inversion show that the distance (D) has the most effective influence in the H/S spatial distribution and the H/S value decreases with the distance from the fault-core. The rheological parameter shows a value similar to the diagenetic H/S values (1-1.5). The resulting equation has a reasonable RMS value of 0.116. The results of the Montecarlo models were finally implemented in FRAP, a fault environment modelling software. It is a true 4D tool that can predict stress conditions and permeability architecture associated to a given faults during single or multiple tectonic events. We present some models of fault-related fracturing among the studied faults performed by FRAP and we compare them with the field measurements, to test the validity of our methodology.

Spatiotemporal patterns of fault slip rates across the Central Sierra Nevada frontal fault zone

NASA Astrophysics Data System (ADS)

Rood, Dylan H.; Burbank, Douglas W.; Finkel, Robert C.

2011-01-01

Patterns in fault slip rates through time and space are examined across the transition from the Sierra Nevada to the Eastern California Shear Zone-Walker Lane belt. At each of four sites along the eastern Sierra Nevada frontal fault zone between 38 and 39° N latitude, geomorphic markers, such as glacial moraines and outwash terraces, are displaced by a suite of range-front normal faults. Using geomorphic mapping, surveying, and 10Be surface exposure dating, mean fault slip rates are defined, and by utilizing markers of different ages (generally, ~ 20 ka and ~ 150 ka), rates through time and interactions among multiple faults are examined over 10 4-10 5 year timescales. At each site for which data are available for the last ~ 150 ky, mean slip rates across the Sierra Nevada frontal fault zone have probably not varied by more than a factor of two over time spans equal to half of the total time interval (~ 20 ky and ~ 150 ky timescales): 0.3 ± 0.1 mm year - 1 (mode and 95% CI) at both Buckeye Creek in the Bridgeport basin and Sonora Junction; and 0.4 + 0.3/-0.1 mm year - 1 along the West Fork of the Carson River at Woodfords. Data permit rates that are relatively constant over the time scales examined. In contrast, slip rates are highly variable in space over the last ~ 20 ky. Slip rates decrease by a factor of 3-5 northward over a distance of ~ 20 km between the northern Mono Basin (1.3 + 0.6/-0.3 mm year - 1 at Lundy Canyon site) to the Bridgeport Basin (0.3 ± 0.1 mm year - 1 ). The 3-fold decrease in the slip rate on the Sierra Nevada frontal fault zone northward from Mono Basin is indicative of a change in the character of faulting north of the Mina Deflection as extension is transferred eastward onto normal faults between the Sierra Nevada and Walker Lane belt. A compilation of regional deformation rates reveals that the spatial pattern of extension rates changes along strike of the Eastern California Shear Zone-Walker Lane belt. South of the Mina Deflection, extension is accommodated within a diffuse zone of normal and oblique faults, with extension rates increasing northward on the Fish Lake Valley fault. Where faults of the Eastern California Shear Zone terminate northward into the Mina Deflection, extension rates increase northward along the Sierra Nevada frontal fault zone to ~ 0.7 mm year - 1 in northern Mono Basin. This spatial pattern suggests that extension is transferred from more easterly fault systems, e.g., Fish Lake Valley fault, and localized on the Sierra Nevada frontal fault zone as the Eastern California Shear Zone-Walker Lane belt faulting is transferred through the Mina Deflection.

Late Quaternary slip rate determination by CRN dating on the Haiyuan fault, China, and implication for complex geometry fault systems

NASA Astrophysics Data System (ADS)

Matrau, Rémi; Klinger, Yann; Van der Woerd, Jérôme; Liu-Zeng, Jing; Li, Zhanfei; Xu, Xiwei

2017-04-01

Late Quaternary slip rate determination by CRN dating on the Haiyuan fault, China, and implication for complex geometry fault systems Matrau Rémi, Klinger Yann, Van der Woerd Jérôme, Liu-Zeng Jing, Li Zhanfei, Xu Xiwei The Haiyuan fault in Gansu Province, China, is a major left-lateral strike-slip fault forming the northeastern boundary of the Tibetan plateau and accommodating part of the deformation from the India-Asia collision. Geomorphic and geodetic studies of the Haiyuan fault show slip rates ranging from 4 mm/yr to 19 mm/yr from east to west along 500 km of the fault. Such discrepancy could be explained by the complex geometry of the fault system, leading to slip distribution on multiple branches. Combining displacement measurements of alluvial terraces from high-resolution Pléiades images and 10Be - 26Al cosmogenic radionuclides (CRN) dating, we bracket the late Quaternary slip rate along the Hasi Shan fault segment (37°00' N, 104°25' E). At our calibration site, terrace riser offsets for 5 terraces ranging from 6 m to 227 m and CRN ages ranging from 6.5±0.6 kyr to 41±4 kyr - yield geological left-lateral slip rates from 2.0 mm/yr to 4.4 mm/yr. We measured consistent terrace riser offset values along the entire 25 km-long segment, which suggests that some external forcing controls the regional river-terrace emplacement, regardless of each specific catchment. Hence, we extend our slip rate determination to the entire Hasi Shan fault segment to be 4.0±1.0 mm/yr since the last 40 kyr. This rate is consistent with other long-term rates of 4 mm/yr to 5 mm/yr east and west of Hasi Shan - as well as geodetic rates of 4 mm/yr to 6 mm/yr west of Hasi Shan. However, Holocene terraces and moraines offsets have suggested higher rates of 15 to 20 mm/yr further west. Such disparate rates may be explained by slip distribution on multiple branches. In particular, the Zhongwei fault splay in the central part of the Haiyuan fault, with a slip rate of 4-5 mm/yr could partly explain the faster rates on the western single stranded Haiyuan fault. In addition we constrained 0.55±0.1 mm/yr of uplift rate along the Hasi Shan, where the fault strike veers southward, indicating slip partitioning. Our slip rate along the Hasi Shan segment is consistent with most of the long-term and short-term slip rates ( 5 mm/yr) measured along the central and eastern parts of the Haiyuan fault. However the discrepancy with other studies to the west highlights the major implication of complex geometries on the slip distribution over large fault systems.

Dizziness in discus throwers is related to motion sickness generated while spinning.

PubMed

Perrin, P; Perrot, C; Deviterne, D; Ragaru, B; Kingma, H

2000-03-01

While both discus and hammer throwing involve rotating movements resulting in the throw of an object, discus throwers sometimes report dizziness, a condition never experienced by hammer throwers. We investigated whether this susceptibility was related to the sensitivity of the thrower or to the type of throwing achieved. For the latter, we compared the determining features of gesture, gaze stabilization and projectile trajectory in both sports. A total of 22 high-level sportsmen in these 2 disciplines, half of them practising both sports, were interviewed. Slow motion video recordings of discus and hammer throwing were examined to determine the visual referential, head movements and plantar surface support area involved at each stage of the motions. Discomfort was reported by 59% of the sportsmen while throwing discus, but by none while throwing hammer. Because several individuals practised both sports, these results exclude the hypothesis of individual susceptibility to dizziness. Video analysis evidenced that during hammer throwing, visual bearings can be used more easily than during discus throwing. Moreover, there is a loss of plantar afferents and generation of head movements liable to induce motion sickness, such as Coriolis acceleration. In conclusion, although hammer and discus-throwing present numerous similarities, we demonstrate here that crucial differences in the specific execution of each sport are responsible for the dizziness experienced by discus throwers.

Is hefting to perceive the affordance for throwing a smart perceptual mechanism?

PubMed

Zhu, Qin; Bingham, Geoffrey P

2008-08-01

G. P. Bingham, R. C. Schmidt, and L. D. Rosenblum (1989) found that, by hefting objects of different sizes and weights, people could choose the optimal weight in each size for throwing to a maximum distance. In Experiment 1, the authors replicated this result. G. P. Bingham et al. hypothesized that hefting is a smart mechanism that allows objects to be perceived in the context of throwing dynamics. This hypothesis entails 2 assumptions. First, hefting by hand is required for information about throwing by hand. The authors tested and confirmed this in Experiments 2 and 3. Second, optimal objects are determined by the dynamics of throwing. In Experiment 4, the authors tested this by measuring throwing release angles and using them with mean thrown distances from Experiment 1 and object sizes and weights to simulate projectile motion and recover release velocities. The results showed that only weight, not size, affects throwing. This failed to provide evidence supporting the particular smart mechanism hypothesis of G. P. Bingham et al. Because the affordance relation is determined in part by the dynamics of projectile motion, the results imply that the affordance is learned from knowledge of results of throwing.

The Acute Effects of Upper Extremity Stretching on Throwing Velocity in Baseball Throwers

PubMed Central

Melton, Jason; Delobel, Ashley; Puentedura, Emilio J.

2013-01-01

Purpose. To examine the effects of static and proprioceptive neuromuscular facilitation (PNF) stretching of the shoulder internal rotators on throwing velocity. Subjects. 27 male throwers (mean age = 25.1 years old, SD = 2.4) with adequate knowledge of demonstrable throwing mechanics. Study Design. Randomized crossover trial with repeated measures. Methods. Subjects warmed up, threw 10 pitches at their maximum velocity, were randomly assigned to 1 of 3 stretching protocols (static, PNF, or no stretch), and then repeated their 10 pitches. Velocities were recorded after each pitch and average and peak velocities were recorded after each session. Results. Data were analyzed using a 3 × 2 repeated measures ANOVA. No significant interaction between stretching and throwing velocity was observed. Main effects for time were not statistically significant. Main effects for the stretching groups were statistically significant. Discussion. Results suggest that stretching of the shoulder internal rotators did not significantly affect throwing velocity immediately after stretching. This may be due to the complexity of the throwing task. Conclusions. Stretching may be included in a thrower's warm-up without any effects on throwing velocity. Further research should be performed using a population with more throwing experience and skill. PMID:26464880

Three-dimensional scapular kinematics during the throwing motion.

PubMed

Meyer, Kristin E; Saether, Erin E; Soiney, Emily K; Shebeck, Meegan S; Paddock, Keith L; Ludewig, Paula M

2008-02-01

Proper scapular motion is crucial for normal shoulder mechanics. Scapular motion affects glenohumeral joint function during throwing, yet little is known about this dynamic activity. Asymptomatic subjects (10 male and 10 female), ages 21 to 45, were analyzed. Electromagnetic surface sensors on the sternum, acromion, and humerus were used to collect 3-D motion data during three trials of low-velocity throwing. Scapular angular position data were described or five predetermined events throughout the throw corresponding with classic descriptions of throwing phases, and trial-to-trial reliability was determined. ANOVA compared scapular angles across events. Subjects demonstrated good to excellent reliability between trials of the throw (ICC 0.74-0.98). The scapula demonstrated a pattern of external rotation, upward rotation (peak of approx. 40 degrees), and poster humeral horizontal abduction. During the arm acceleration phase, the scapula moved toward greater internal rotation and began anteriorly tilting. At maximum humeral internal rotation, the scapula ended in internal rotation (55 degrees), upward rotation (20 degrees), and anterior tilting (3 degrees). Significant differences in scapular position (p<0.05) were identified across the throwing motion. Scapular data identify events in the throwing motion in which throwers may be more susceptible to shoulder pathologies related to abnormal scapular kinematics.

Motion-plane dependency of the range of dart throw motion and the effects of tendon action due to finger extrinsic muscles during the motion.

PubMed

Mitsukane, Masahiro; Sekiya, Noboru; Kamono, Arinori; Nakabo, Tohru

2018-03-01

[Purpose] To clarify the motion-plane dependency of the range of dart throw motion and the effects of tendon action due to long finger flexors and extensors during the motion. [Subjects and Methods] Forty healthy subjects attended the experiment, and the active range of wrist motion in seven motion planes was measured with an originally designed apparatus. [Results] The reliability of the measurement was acceptable. The range of dart throw motion depended on the motion planes, with a maximum at around the motion plane of 45° from the sagittal plane (45° of pronation). The tendon action of long finger muscles was shown in dart throw motion except in 45° of pronation. [Conclusion] Motion-plane dependency of the range of dart throw motion exists in healthy subjects. The absence of tendon action due to finger extrinsic muscles in dart throw motion at 45° might be one of the causes of the advantage of dart throw motion.

Elastic block and strain modeling of GPS data around the Haiyuan-Liupanshan fault, northeastern Tibetan Plateau

NASA Astrophysics Data System (ADS)

Li, Yanchuan; Shan, Xinjian; Qu, Chunyan; Zhang, Yingfeng; Song, Xiaogang; Jiang, Yu; Zhang, Guohong; Nocquet, Jean-Mathieu; Gong, Wenyu; Gan, Weijun; Wang, Chisheng

2017-12-01

Based on the dense GPS velocity field in the northeastern margin of the Tibetan Plateau from 1999 to 2016, we have produced the deformation and strain characteristics of the Haiyuan fault and the Liupanshan fault. Estimated long-term slip rate along the Haiyuan-Liupanshan fault zones show a gradual decrease from 6.4 ± 1.6 mm/yr at the Tuolaishan fault to 2.9 ± 1.2 mm/yr at the Southern Liupanshan fault. Left-lateral thrusting movement was inverted for the Xiangshan-Tianjingshan fault (XS-TJS), which has an average slip rate of 2.1 ± 3.4 mm/yr during the study period. We also calculated the heterogeneous distribution of interseismic coupling along the fault zones. Our result also shows the locking depth of the Tianzhu seismic gap is ∼22 km. The slip rate deficit, the seismic moment accumulation rate, and the Coulomb stress accumulation rate are high on the fault planes, whereas the second invariant of the strain rate is low at the surface. The Liupanshan fault is locked to a depth of ∼23 km, and the corresponding seismic moment accumulation rate on the fault plane is high, while the strain rate at the surface is low. The accumulated strain along the Tianzhu seismic gap and the Liupanshan fault could be balanced by earthquakes with magnitudes of Mw7.9 and Mw7.4, considering the absence of large earthquakes over the last 1000 years and 1400 years respectively. The Haiyuan segments had ruptured during 1920 Haiyuan earthquake, and the estimated locking depth for period 1999-2016 is 5-10 km. Its seismic moment accumulation rate at depth is low and the strain rate at the surface is high. Our result indicates that 70% of the strike-slip along the Haiyuan segments transforms into thrusting along the Liupanshan fault, while the remaining 30% is related to the orogeny of the Liupanshan. For slip between the Haiyuan fault and the XS-TJS, about 27-34% of the slip is partitioned on the XS-TJS.

Optimal strategies for throwing accurately

PubMed Central

2017-01-01

The accuracy of throwing in games and sports is governed by how errors in planning and initial conditions are propagated by the dynamics of the projectile. In the simplest setting, the projectile path is typically described by a deterministic parabolic trajectory which has the potential to amplify noisy launch conditions. By analysing how parabolic trajectories propagate errors, we show how to devise optimal strategies for a throwing task demanding accuracy. Our calculations explain observed speed–accuracy trade-offs, preferred throwing style of overarm versus underarm, and strategies for games such as dart throwing, despite having left out most biological complexities. As our criteria for optimal performance depend on the target location, shape and the level of uncertainty in planning, they also naturally suggest an iterative scheme to learn throwing strategies by trial and error. PMID:28484641

Optimal strategies for throwing accurately

NASA Astrophysics Data System (ADS)

Venkadesan, M.; Mahadevan, L.

2017-04-01

The accuracy of throwing in games and sports is governed by how errors in planning and initial conditions are propagated by the dynamics of the projectile. In the simplest setting, the projectile path is typically described by a deterministic parabolic trajectory which has the potential to amplify noisy launch conditions. By analysing how parabolic trajectories propagate errors, we show how to devise optimal strategies for a throwing task demanding accuracy. Our calculations explain observed speed-accuracy trade-offs, preferred throwing style of overarm versus underarm, and strategies for games such as dart throwing, despite having left out most biological complexities. As our criteria for optimal performance depend on the target location, shape and the level of uncertainty in planning, they also naturally suggest an iterative scheme to learn throwing strategies by trial and error.

Constant Fault Slip-Rates Over Hundreds of Millenia Constrained By Deformed Quaternary Palaeoshorelines: the Vibo and Capo D'Orlando Faults, Southern Italy.

NASA Astrophysics Data System (ADS)

Meschis, M.; Roberts, G.; Robertson, J.; Houghton, S.; Briant, R. M.

2017-12-01

Whether slip-rates on active faults accumulated over multiple seismic events is constant or varying over tens to hundreds of millenia timescales is an open question that can be addressed through study of deformed Quaternary palaeoshorelines. It is important to know the answer so that one can judge whether shorter timescale measurements (e.g. Holocene palaeoseismology or decadal geodesy) are suitable for determining earthquake recurrence intervals for Probabilistic Seismic Hazard Assessment or more suitable for studying temporal earthquake clustering. We present results from the Vibo Fault and the Capo D'Orlando Fault, that lie within the deforming Calabrian Arc, which has experienced damaging seismic events such as the 1908 Messina Strait earthquake ( Mw 7) and the 1905 Capo Vaticano earthquake ( Mw 7). These normal faults deform uplifted Late Quaternary palaeoshorelines, which outcrop mainly within their hangingwalls, but also partially in their footwalls, showing that a regional subduction and mantle-related uplift outpaces local fault-related subsidence. Through (1) field and DEM-based mapping of palaeoshorelines, both up flights of successively higher, older inner edges, and along the strike of the faults, and (2) utilisation of synchronous correlation of non-uniformly-spaced inner edge elevations with non-uniformly spaced sea-level highstand ages, we show that slip-rates decrease towards fault tips and that slip-rates have remained constant since 340 ka (given the time resolution we obtain). The slip-rates for the Capo D'Orlando Fault and Vibo Fault are 0.61mm/yr and 1mm/yr respectively. We show that the along-strike gradients in slip-rate towards fault tips differ for the two faults hinting at fault interaction and also discuss this in terms of other regions of extension like the Gulf of Corinth, Greece, where slip-rate has been shown to change through time through the Quaternary. We make the point that slip-rates may change through time as fault systems grow and fault interaction changes due to geometrical effects.

Characterizing the Alpine Fault Strike Slip System Using a Novel Method for Analyzing GPS Data

NASA Astrophysics Data System (ADS)

Haines, A. J.; Dimitrova, L. L.; Wallace, L. M.; Williams, C. A.

2013-12-01

Plate motion across the South Island is dominated by right-lateral strike-slip (38-39 mm/yr total in the direction parallel to the Alpine Fault), with a small convergent component (8-10 mm/yr). The Alpine Fault is the most active fault in the region taking up 27×5 mm/yr in right-lateral strike-slip and ~10 mm/yr in dip-slip. It fails in large >=7 Mw earthquakes with recurrence time of 200-400 years and last ruptured around 1717. A significant component of the plate motion budget must occur on faults other than the Alpine Fault, but this is not fully accounted for in catalogues of known active faults. In the central part of the South Island, low slip rate active faults are not well-expressed due to the rapid erosion of the Southern Alps and deposition of these sediments onto the Canterbury plains; the devastating 2010 Darfield earthquake sequence occurred on such previously unknown faults. We apply a novel inversion technique (Dimitrova et al. 2012, 2013) to dense campaign GPS velocities in the region to solve for the vertical derivatives of horizontal stress (VDoHS) rates which are a substantially higher resolution expression of subsurface sources of ongoing deformation than the GPS velocities or GPS derived strain rates. Integrating the VDoHS rates gives us strain rates. Relationships between the VDoHS and strain rates allow us to calculate the variation in fault slip rate and locking depth for the identified faults; e.g., we estimate along fault variations for locking depth and slip rate for the Alpine Fault in the South Island in good agreement with previous estimates, and provide first estimates for those properties on the smaller, previously-uncharacterized faults which account for as much as 50% of the plate motion depending on location. For the first time, we note that the area between the Alpine Fault and the Main Divide of the Southern Alps is undergoing extensional areal strain, potentially indicative of gravitational collapse of the Southern Alps. The Arthur's Pass section of the Alpine Fault exhibits no shear component in the spatial derivatives of the VDoHS rates, in marked contrast to the Alpine Fault segments just northeast and southwest, suggesting that post-seismic deformation related to the 1994 Arthur's Pass earthquake is masking the signal from the Alpine Fault beneath. We characterize in detail the transfer of slip further north into the Marlborough Fault System, where we find much of the slip on the Alpine Fault passes onto the Kelly and Hope Faults, in accord with previous geological studies.

Knickpoint retreat and landscape evolution of the Amatlán de Cañas half-graben (northern sector of Jalisco Block, western Mexico)

NASA Astrophysics Data System (ADS)

Castillo, Miguel; Ferrari, Luca; Muñoz-Salinas, Esperanza

2017-08-01

Rivers are known to respond to changes in the rate of rock uplift by propagating knickpoints through the fluvial network. Downstream of knickpoints, river incision increases local relief producing also the steepening of hillslopes. Thus, knickpoints convey information about the amount of rock uplift to which the fluvial system must respond. Because the incisional pulse produced by the rapid rock uplift is recorded in the topography of channels, the analysis of longitudinal profiles can be used for evaluating the response of landscape to tectonic activity. Here we analyse the longitudinal profile of rivers (n = 84) and the river basin topography (n = 72) with the aim of unravelling the evolution of the Amatlán de Cañas half-graben (ACHG), a Plio-Quaternary structure located in the northern sector of the Jalisco Block (west-central Mexico). Our results indicate that two rock uplift pulses formed the footwall of the ACHG. The distance of knickpoint retreat from the fault scarp exhibit a strong correlation with the stream length (R2 = 0.80), highlighting the importance of stream discharge on knickpoint migration. Clustering of high values of relief, river incision and normalised channel steepness index (ksn) around the centre of the footwall confirms that this is the zone of maximum throw. The propagation of knickpoints along Ameca river is producing the degradation of fans and relief rejuvenation. Using compiled data of knickpoint retreat rates of other tectonically active landscapes, it was found that the stream discharge and the timing and rate of rock uplift are together a first order control on the rate of knickpoint recession. This study supports the idea that the understanding of knickpoints is crucial to unravel the evolution of tectonically active landscapes.

Limit on slip rate and timing of recent seismic ground-ruptures on the Jinghong fault, SE of the eastern Himalayan syntaxis

NASA Astrophysics Data System (ADS)

Shi, Xuhua; Weldon, Ray; Liu-Zeng, Jing; Wang, Yu; Weldon, Elise; Sieh, Kerry; Li, Zhigang; Zhang, Jinyu; Yao, Wenqian; Li, Zhanfei

2018-06-01

Quantifying slip rates and earthquake occurrence of active faults on the Shan Plateau, southeast of the eastern Himalayan syntaxis, is critical to assessing the seismic hazard and understanding the kinematics and geodynamics of this region. Most previous estimates of slip rates are averaged over either many millions of years using offset geological markers or decades using GPS. Well-constrained millennial slip rates of these faults remain sparse and constraints on recurrence rates of damaging earthquakes exist only for a few faults. Here we investigate the millennial slip rate and timing of recent earthquakes on the Jinghong fault, one of the geomorphically most significant sinistral-slip faults on the central Shan Plateau. We map and reconstruct fault offset (18 ± 5 m) of alluvial fan features at Manpa on the central Jinghong fault, using a 0.1 m-resolution digital surface model obtained from an unmanned aerial vehicle survey. We establish a slip rate, ≤2.5 ± 0.7 mm/yr over the past 7000 years, using pit-exposed stratigraphy. This millennial slip rate is consistent with rates averaged over both decadal and million-year timescales. Excavations at three sites near the town of Gelanghe on the northeastern Jinghong fault demonstrate 1) that the last seismic ground-rupture occurred between 482 and 889 cal yr BP, most likely in the narrower window 824-767 cal yr BP, if the lack of large earthquakes in the historical earthquake record is reliable, and 2) that multiple fault ruptures have occurred since 3618 cal yr BP. Combining this finding with a lack of large earthquakes in the 800-year-long Chinese historic record in this region, we suggest an average recurrence interval of seismic ground-ruptures on the order of 1000 years. This recurrence interval is consistent with the slip rate of the Jinghong fault and the size and earthquake frequency on other sinistral faults on the Shan Plateau.

Post-seismic and interseismic fault creep I: model description

NASA Astrophysics Data System (ADS)

Hetland, E. A.; Simons, M.; Dunham, E. M.

2010-04-01

We present a model of localized, aseismic fault creep during the full interseismic period, including both transient and steady fault creep, in response to a sequence of imposed coseismic slip events and tectonic loading. We consider the behaviour of models with linear viscous, non-linear viscous, rate-dependent friction, and rate- and state-dependent friction fault rheologies. Both the transient post-seismic creep and the pattern of steady interseismic creep rates surrounding asperities depend on recent coseismic slip and fault rheologies. In these models, post-seismic fault creep is manifest as pulses of elevated creep rates that propagate from the coseismic slip, these pulses feature sharper fronts and are longer lived in models with rate-state friction compared to other models. With small characteristic slip distances in rate-state friction models, interseismic creep is similar to that in models with rate-dependent friction faults, except for the earliest periods of post-seismic creep. Our model can be used to constrain fault rheologies from geodetic observations in cases where the coseismic slip history is relatively well known. When only considering surface deformation over a short period of time, there are strong trade-offs between fault rheology and the details of the imposed coseismic slip. Geodetic observations over longer times following an earthquake will reduce these trade-offs, while simultaneous modelling of interseismic and post-seismic observations provide the strongest constraints on fault rheologies.

Determinant Factors of Physical Performance and Specific Throwing in Handball Players of Different Ages.

PubMed

Ortega-Becerra, Manuel; Pareja-Blanco, Fernando; Jiménez-Reyes, Pedro; Cuadrado-Peñafiel, Víctor; González-Badillo, Juan J

2018-06-01

Ortega-Becerra, M, Pareja-Blanco, F, Jiménez-Reyes, P, Cuadrado-Peñafiel, V, and González-Badillo, JJ. Determinant factors of physical performance and specific throwing in handball players of different ages. J Strength Cond Res 32(6): 1778-1786, 2018-This study aimed to analyze various fitness qualities in handball players of different ages and to determine the relationships between these parameters and throwing velocity. A total of 44 handball players participated, pooled by age groups: professional (ELITE, n = 13); under-18 (U18, n = 16); under-16 (U16, n = 15). The following tests were completed: 20-m running sprints; countermovement jumps (CMJs); jump squat to determine the load that elicited ∼20 cm jump height (JSLOAD-20 cm); a progressive loading test in full squat and bench press to determine the load that elicited ∼1 m·s (SQ-V1-LOAD and BP-V1-LOAD); and handball throwing (jump throw and 3-step throw). ELITE showed greater performance in almost all sprint distances, CMJ, JSLOAD-20 cm, and bench press strength than U18 and U16. The differences between U18 and U16 were unclear for these variables. ELITE also showed greater (p < 0.001) performance for squat strength and throwing than U18 and U16, and U18 attained greater performance (p ≤ 0.05) for these variables than U16. Throwing performance correlated (p ≤ 0.05) with sprint times (r = -0.31; -0.51) and jump ability (CMJ: r = 0.39; 0.56 and JSLOAD-20 cm: r = 0.57; 0.60). Muscle strength was also associated (p < 0.001) with both types of throw (SQ-V1-LOAD: r = 0.66; 0.76; and BP-V1-LOAD: r = 0.33; 0.70). These results indicate that handball throwing velocity is strongly associated with lower-limb strength, although upper-limb strength, jumping and sprint capacities also play a relevant role in throwing performance, suggesting the need for coaches to include proper strength programs to improve handball players' throwing velocity.

Prediction of shot success for basketball free throws: visual search strategy.

PubMed

Uchida, Yusuke; Mizuguchi, Nobuaki; Honda, Masaaki; Kanosue, Kazuyuki

2014-01-01

In ball games, players have to pay close attention to visual information in order to predict the movements of both the opponents and the ball. Previous studies have indicated that players primarily utilise cues concerning the ball and opponents' body motion. The information acquired must be effective for observing players to select the subsequent action. The present study evaluated the effects of changes in the video replay speed on the spatial visual search strategy and ability to predict free throw success. We compared eye movements made while observing a basketball free throw by novices and experienced basketball players. Correct response rates were close to chance (50%) at all video speeds for the novices. The correct response rate of experienced players was significantly above chance (and significantly above that of the novices) at the normal speed, but was not different from chance at both slow and fast speeds. Experienced players gazed more on the lower part of the player's body when viewing a normal speed video than the novices. The players likely detected critical visual information to predict shot success by properly moving their gaze according to the shooter's movements. This pattern did not change when the video speed was decreased, but changed when it was increased. These findings suggest that temporal information is important for predicting action outcomes and that such outcomes are sensitive to video speed.

Coseismic slip variation assessed from terrestrial lidar scans of the El Mayor-Cucapah surface rupture

NASA Astrophysics Data System (ADS)

Gold, Peter O.; Oskin, Michael E.; Elliott, Austin J.; Hinojosa-Corona, Alejandro; Taylor, Michael H.; Kreylos, Oliver; Cowgill, Eric

2013-03-01

We analyze high-resolution (>103 points/m2) terrestrial lidar surveys of the 4 April 2010 El Mayor-Cucapah earthquake rupture (Baja California, Mexico), collected at three sites 12-18 days after the event. Using point cloud-based tools in an immersive visualization environment, we quantify coseismic fault slip for hundreds of meters along strike and construct densely constrained along-strike slip distributions from measurements of offset landforms. Uncertainty bounds for each offset, determined empirically by repeatedly measuring offsets at each site sequentially, illuminate measurement uncertainties that are difficult to quantify in the field. These uncertainties are used to define length scales over which variability in slip distributions may be assumed to reflect either recognizable earthquake mechanisms or measurement noise. At two sites characterized by 2-3 m of concentrated right-oblique slip, repeat measurements yield 2σ uncertainties of ±11-12%. Each site encompasses ∼200 m along strike, and a smoothed linear slip gradient satisfies all measurement distributions, implying along-fault strains of ∼10-3. Conversely, the common practice of defining the slip curve by the local slip maxima distorts the curve, overestimates along-fault strain, and may overestimate actual fault slip by favoring measurements with large, positive, uncertainties. At a third site characterized by 1-2.5 m of diffuse normal slip, repeat measurements of fault throw summed along fault-perpendicular profiles yield 2σ uncertainties of ±17%. Here, a low order polynomial fit through the measurement averages best approximates surface slip. However independent measurements of off-fault strain accommodated by hanging wall flexure suggest that over the ∼200 m length of this site, a linear interpolation through the average values for the slip maxima at either end of this site most accurately represents subsurface displacement. In aggregate, these datasets show that given uncertainties of greater than ±11% (2σ), slip distributions over shorter scales are likely to be less uneven than those derived from a single set of field- or lidar-based measurements. This suggests that the relatively smooth slip curves we obtain over ∼102 m distances reflect real physical phenomena, whereas short wavelength variability over ∼100-101 m distances can be attributed to measurement uncertainty.

A comparison of the technique of the football quarterback pass between high school and university athletes.

PubMed

Toffan, Adam; Alexander, Marion J L; Peeler, Jason

2017-07-28

The purpose of the study was to compare the most effective joint movements, segment velocities and body positions to perform the fastest and most accurate pass of high school and university football quarterbacks. Secondary purposes were to develop a quarterback throwing test to assess skill level, to determine which kinematic variables were different between high school and university athletes as well as to determine which variables were significant predictors of quarterback throwing test performance. Ten high school and ten university athletes were filmed for the study, performing nine passes at a target and two passes for maximum distance. Thirty variables were measured using Dartfish Team Pro 4.5.2 video analysis system, and Microsoft Excel was used for statistical analysis. University athletes scored slightly higher than the high school athletes on the throwing test, however this result was not statistically significant. Correlation analysis and forward stepwise multiple regression analysis was performed on both the high school players and the university players in order to determine which variables were significant predictors of throwing test score. Ball velocity was determined to have the strongest predictive effect on throwing test score (r = 0.900) for the high school athletes, however, position of the back foot at release was also determined to be important (r = 0.661) for the university group. Several significant differences in throwing technique between groups were noted during the pass, however, body position at release showed the greatest differences between the two groups. High school players could benefit from more complete weight transfer and decreased throw time to increase throwing test score. University athletes could benefit from increased throw time and greater range of motion in external shoulder rotation and trunk rotation to increase their throwing test score. Coaches and practitioners will be able to use the findings of this research to help improve these and related throwing variables in their high school and university quarterbacks.

Visual Perspective and Feedback Guidance for VR Free-Throw Training.

PubMed

Covaci, Alexandra; Olivier, Anne-Hélène; Multon, Franck

2015-01-01

Accurate distance perception and natural interactions are mandatory conditions when training precision aiming tasks in VR. However, many factors specific to virtual environments (VEs) lead to differences in the way users execute a motor task in VR versus the real world. To investigate these differences, the authors performed a study on basketball beginners' free-throw performance in VEs under different visual conditions. Although the success rate is not statistically different, some adaptations occurred in the way the users performed the task, depending on the visual conditions. In the third-person perspective visual condition, the release parameters indicate that the users more accurately estimated distance to target. Adding visual guidance information (gradual depth information showing the ideal ball trajectory) also led to more natural motor behavior. The final aim of this study was to develop a reliable basketball free-throw training system in VEs, so the authors compared beginners' performances in VR with experts' models of performance. Their results show that most of the performance variables tended to evolve closer to the experts' performance during the training in the VE.

Transfer of motor and perceptual skills from basketball to darts

PubMed Central

Rienhoff, Rebecca; Hopwood, Melissa J.; Fischer, Lennart; Strauss, Bernd; Baker, Joseph; Schorer, Jörg

2013-01-01

The quiet eye is a perceptual skill associated with expertise and superior performance; however, little is known about the transfer of quiet eye across domains. We attempted to replicate previous skill-based differences in quiet eye and investigated whether transfer of motor and perceptual skills occurs between similar tasks. Throwing accuracy and quiet eye duration for skilled and less-skilled basketball players were examined in basketball free throw shooting and the transfer task of dart throwing. Skilled basketball players showed significantly higher throwing accuracy and longer quiet eye duration in the basketball free throw task compared to their less-skilled counterparts. Further, skilled basketball players showed positive transfer from basketball to dart throwing in accuracy but not in quiet eye duration. Our results raise interesting questions regarding the measurement of transfer between skills. PMID:24062703

Throwing enhances humeral shaft cortical bone properties in pre-pubertal baseball players: a 12-month longitudinal pilot study.

PubMed

Weatherholt, Alyssa M; Warden, Stuart J

2018-06-01

To explore throwing athletes as a prospective, within-subject controlled model for studying the response of the skeleton to exercise. Male pre-pubertal throwing athletes (n=12; age=10.3±0.6 yrs) had distal humerus cortical volumetric bone mineral density (Ct.vBMD), cortical bone mineral content (Ct.BMC), total area (Tt.Ar), cortical area (Ct.Ar), medullary area (Me.Ar), cortical thickness (Ct.Th) and polar moment of inertia (IP) assessed within their throwing (exercised) and nonthrowing (control) arms by peripheral quantitative computed tomography at baseline and 12 months. Throwing-to-nonthrowing arm percent differences (i.e. bilateral asymmetry) were compared over time. Over 12 months, the throwing arm gained 4.3% (95% Cl=1.1% to 7.5%), 2.9% (95% Cl=0.3% to 5.4%), 3.9% (95% Cl=0.7% to 7.0%), and 8.2% (95% Cl=2.0% to 6.8%) more Ct.BMC, Ct.Ar, Tt.Ar, and I P than the nonthrowing arm, respectively (all p<0.05). There was no significant effect of throwing on Ct.vBMD, Ct.Th and Me.Ar (all p=0.18-0.82). Throwing induced surface-specific cortical bone adaptation at the distal humeral diaphysis that contributed to a gain in estimated strength. These longitudinal pilot data support the utility of throwing athletes as a within-subject controlled model to explore factors influencing exercise-induced bone adaptation during the critical growing years.

A paleoseismic transect across the northwestern Basin and Range Province, northwestern Nevada and northeastern California, USA

USGS Publications Warehouse

Personius, Stephen; Briggs, Richard; Maharrey, J. Zebulon; Angster, Stephen J.; Mahan, Shannon

2017-01-01

We use new and existing data to compile a record of ∼18 latest Quaternary large-magnitude surface-rupturing earthquakes on 7 fault zones in the northwestern Basin and Range Province of northwestern Nevada and northeastern California. The most recent earthquake on all faults postdates the ca. 18–15 ka last glacial highstand of pluvial Lake Lahontan and other pluvial lakes in the region. These lacustrine data provide a window in which we calculate latest Quaternary vertical slip rates and compare them with rates of modern deformation in a global positioning system (GPS) transect spanning the region. Average vertical slip rates on these fault zones range from 0.1 to 0.8 mm/yr and total ∼2 mm/yr across a 265-km-wide transect from near Paradise Valley, Nevada, to the Warner Mountains in California. We converted vertical slip rates to horizontal extension rates using fault dips of 30°–60°, and then compared the extension rates to GPS-derived rates of modern (last 7–9 yr) deformation. Our preferred fault dip values (45°–55°) yield estimated long-term extension rates (1.3–1.9 mm/yr) that underestimate our modern rate (2.4 mm/yr) by ∼21%–46%. The most likely sources of this underestimate are geologically unrecognizable deformation from moderate-sized earthquakes and unaccounted-for coseismic off-fault deformation from large surface-rupturing earthquakes. However, fault dip values of ≤40° yield long-term rates comparable to or greater than modern rates, so an alternative explanation is that fault dips are closer to 40° than our preferred values. We speculate that the large component of right-lateral shear apparent in the GPS signal is partitioned on faults with primary strike-slip displacement, such as the Long Valley fault zone, and as not easily detected oblique slip on favorably oriented normal faults in the region.

Artificial Intelligence in Sports Biomechanics: New Dawn or False Hope?

PubMed Central

Bartlett, Roger

2006-01-01

This article reviews developments in the use of Artificial Intelligence (AI) in sports biomechanics over the last decade. It outlines possible uses of Expert Systems as diagnostic tools for evaluating faults in sports movements (‘techniques’) and presents some example knowledge rules for such an expert system. It then compares the analysis of sports techniques, in which Expert Systems have found little place to date, with gait analysis, in which they are routinely used. Consideration is then given to the use of Artificial Neural Networks (ANNs) in sports biomechanics, focusing on Kohonen self-organizing maps, which have been the most widely used in technique analysis, and multi-layer networks, which have been far more widely used in biomechanics in general. Examples of the use of ANNs in sports biomechanics are presented for javelin and discus throwing, shot putting and football kicking. I also present an example of the use of Evolutionary Computation in movement optimization in the soccer throw in, which predicted an optimal technique close to that in the coaching literature. After briefly overviewing the use of AI in both sports science and biomechanics in general, the article concludes with some speculations about future uses of AI in sports biomechanics. Key Points Expert Systems remain almost unused in sports biomechanics, unlike in the similar discipline of gait analysis. Artificial Neural Networks, particularly Kohonen Maps, have been used, although their full value remains unclear. Other AI applications, including Evolutionary Computation, have received little attention. PMID:24357939

Artificial intelligence in sports biomechanics: new dawn or false hope?

PubMed

Bartlett, Roger

2006-12-15

This article reviews developments in the use of Artificial Intelligence (AI) in sports biomechanics over the last decade. It outlines possible uses of Expert Systems as diagnostic tools for evaluating faults in sports movements ('techniques') and presents some example knowledge rules for such an expert system. It then compares the analysis of sports techniques, in which Expert Systems have found little place to date, with gait analysis, in which they are routinely used. Consideration is then given to the use of Artificial Neural Networks (ANNs) in sports biomechanics, focusing on Kohonen self-organizing maps, which have been the most widely used in technique analysis, and multi-layer networks, which have been far more widely used in biomechanics in general. Examples of the use of ANNs in sports biomechanics are presented for javelin and discus throwing, shot putting and football kicking. I also present an example of the use of Evolutionary Computation in movement optimization in the soccer throw in, which predicted an optimal technique close to that in the coaching literature. After briefly overviewing the use of AI in both sports science and biomechanics in general, the article concludes with some speculations about future uses of AI in sports biomechanics. Key PointsExpert Systems remain almost unused in sports biomechanics, unlike in the similar discipline of gait analysis.Artificial Neural Networks, particularly Kohonen Maps, have been used, although their full value remains unclear.Other AI applications, including Evolutionary Computation, have received little attention.

Time-motion analysis of goalball players in attacks: differences of the player positions and the throwing techniques.

PubMed

Monezi, Lucas Antônio; Magalhães, Thiago Pinguelli; Morato, Márcio Pereira; Mercadante, Luciano Allegretti; Furtado, Otávio Luis Piva da Cunha; Misuta, Milton Shoiti

2018-03-26

In this study, we aimed to analyse goalball players time-motion variables (distance covered, time spent, maximum and average velocities) in official goalball match attacks, taking into account the attack phases (preparation and throwing), player position (centres and wings) and throwing techniques (frontal, spin and between the legs). A total of 365 attacks were assessed using a video based method (2D) through manual tracking using the Dvideo system. Inferential non-parametric statistics were applied for comparison of preparation vs. throwing phase, wings vs. centres and, among the throwing techniques, frontal, spin and between the legs. Significant differences were found between the attack preparation versus the throwing phase for all player time-motion variables: distance covered, time spent, maximum player velocity and average player velocity. Wing players performed most of the throws (85%) and covered longer distances than centres (1.65 vs 0.31 m). The between the legs and the spin throwing techniques presented greater values for most of the time-motion variables (distance covered, time spent and maximum player velocity) than did the frontal technique in both attack phases. These findings provide important information regarding players' movement patterns during goalball matches that can be used to plan more effective training.

Relationship between throwing velocity, muscle power, and bar velocity during bench press in elite handball players.

PubMed

Marques, Mario C; van den Tilaar, Roland; Vescovi, Jason D; Gonzalez-Badillo, Juan Jose

2007-12-01

The purpose of this study was to examine the relationship between ball-throwing velocity during a 3-step running throw and dynamic strength, power, and bar velocity during a concentric-only bench-press exercise in team-handball players. Fourteen elite senior male team-handball players volunteered to participate. Each volunteer had power and bar velocity measured during a concentric-only bench-press test with 26, 36, and 46 kg, as well as having 1-repetition-maximum (1-RMBP) strength determined. Ball-throwing velocity was evaluated with a standard 3-step running throw using a radar gun. Ball-throwing velocity was related to the absolute load lifted during the 1-RMBP (r = .637, P = .014), peak power using 36 kg (r = .586, P = .028) and 46 kg (r = .582, P = .029), and peak bar velocity using 26 kg (r = .563, P = .036) and 36 kg (r = .625, P = .017). The results indicate that throwing velocity of elite team-handball players is related to maximal dynamic strength, peak power, and peak bar velocity. Thus, a training regimen designed to improve ball-throwing velocity in elite male team-handball players should include exercises that are aimed at increasing both strength and power in the upper body.

Late Pleistocene, Holocene, and decadal constancy of slip-rate of the Doruneh strike-slip fault, Iran.

NASA Astrophysics Data System (ADS)

Walker, R. T.; Fattahi, M.; Mousavi, Z.; Pathier, E.; Sloan, R. A.; Talebian, M.; Thomas, A. L.; Walpersdorf, A.

2014-12-01

The Doruneh left-lateral strike-slip fault of NE Iran has a prominent expression in the landscape, showing that the fault is active in the late Quaternary. Existing estimates of its slip-rate vary, however, which has led to suggestions that it may exhibit temporal changes in activity. Using high-resolution optical satellite imagery we make reconstructions of displacement across four alluvial fans that cross the Doruneh fault, and determine the ages of these fans using luminescence dating, combined with U-series dating of pedogenic carbonates in one case. The four fans, which vary in age from 10-100 kyr, yield estimates of slip rate of ~2-3 mm/yr. We compare the average slip-rate measurements to the rate of accumulation of strain across the Doruneh fault using GPS and InSAR measurements, and find that the slip-rate is likely to have remained constant - within the uncertainty of our measurements - over the last ~100 ka. The slip-rate that we measure is consistent with the E-W left-lateral Doruneh fault accommodating N-S right-lateral faulting by 'bookshelf' faulting, with clockwise rotation about a vertical axis, in a similar manner to the Eastern California Shear Zone.

Constraining slip rates and spacings for active normal faults

NASA Astrophysics Data System (ADS)

Cowie, Patience A.; Roberts, Gerald P.

2001-12-01

Numerous observations of extensional provinces indicate that neighbouring faults commonly slip at different rates and, moreover, may be active over different time intervals. These published observations include variations in slip rate measured along-strike of a fault array or fault zone, as well as significant across-strike differences in the timing and rates of movement on faults that have a similar orientation with respect to the regional stress field. Here we review published examples from the western USA, the North Sea, and central Greece, and present new data from the Italian Apennines that support the idea that such variations are systematic and thus to some extent predictable. The basis for the prediction is that: (1) the way in which a fault grows is fundamentally controlled by the ratio of maximum displacement to length, and (2) the regional strain rate must remain approximately constant through time. We show how data on fault lengths and displacements can be used to model the observed patterns of long-term slip rate where measured values are sparse. Specifically, we estimate the magnitude of spatial variation in slip rate along-strike and relate it to the across-strike spacing between active faults.

Intrinsic And Extrinsic Controls On Unsteady Deformation Rates, Northern Apennine Mountains, Italy

NASA Astrophysics Data System (ADS)

Anastasio, D. J.; Gunderson, K. L.; Pazzaglia, F. J.; Kodama, K. P.

2017-12-01

The slip rates of faults in the Northern Apennine Mountains were unsteady at 104-105 year timescales during the Neogene and Quaternary. Fault slip rates were recovered from growth strata and uplifted fluvial terraces associated with the Salsomaggiore, Quatto Castella, and Castevetro fault-related folds, sampled along the Stirone, Enza, and Panaro Rivers, respectively. The forelimb stratigraphy of each anticline was dated using rock magnetic-based cyclostratigraphy, which varies with Milankovitch periodicity, multispecies biostratigraphy, magnetostratigraphy, OSL luminescence dating, TCN burial dating, and radiocarbon dating of uplifted and folded fluvial terraces. Fault slip magnitudes were constrained with trishear forward models. We observed decoupled deformation and sediment accumulation rates at each structure. From 3.5Ma deformation of a thick and thin-skinned thrusts was temporally variable and controlled by intrinsic rock processes, whereas, the more regional Pede-Apenninic thrust fault, a thick-skinned thrust underlying the mountain front, was likely activated because of extrinsic forcing from foreland basin sedimentation rate accelerations since 1.4Ma. We found that reconstructed slip rate variability increased as the time resolution increased. The reconstructed slip history of the thin-skinned thrust faults was characterized relatively long, slow fold growth and associated fault slip, punctuated by shorter, more rapid periods limb rotation, and slip on the underlying thrust fault timed asynchronously. Thrust fault slip rates slip rates were ≤ 0.1 to 6 mm/yr at these intermediate timescales. The variability of slip rates on the thrusts is likely related to strain partitioning neighboring faults within the orogenic wedge. The studied structures slowed down at 1Ma when there was a switch to slower synchronous fault slip coincident with orogenic wedge thickening due to the emplacement of the out of sequence Pene-Apenninic thrust fault that was emplaced at 1.4±0.7 mm/yr. Both tectonic control and climate controlled variability on syntectonic sedimentation was observed in the growth sections.

Analysis of the geological structure and tectonic evolution of Xingning-Jinghai sag in deep water area, northern South China Sea

NASA Astrophysics Data System (ADS)

Han, Xiaoying; Ren, Jianye; Lin, Zi; Yang, Linlong

2015-04-01

Recent years, oil and gas exploration of the Pearl River Mouth Basin in the northern margin of South China Sea continuously achieved historic breakthroughs. The Xingning-Jinghai sag, which is located in southeast of the Pearl River Mouth Basin, is a deep-water sag with a great exploration potential. Its tectonic evolution is extremely complex. It experienced Mesozoic subduction to Cenozoic intra-continental rifting background, and finally evolved into a deep-water sag of the northern continental margin of South China Sea. The geological characteristics and the tectonic evolution of Xingning-Jinghai sag was closely related to the process of formation and evolution of the passive continental margin of the northern South China Sea. It is confirmed by many geophysical data that compared with adjacent Chaoshan depression, the crustal thickness of Xingning-Jinghai sag was rapidly thinning, and it developed detachment faults with later magmatic intrusion. The development of detachment faults have dynamic significance for the spreading of the South China Sea. Based on the seismic geological interpretation of 2D seismic data in the study area, the characteristics of detachment fault and supra-detachment basin have been proposed in this study. The characteristics of the detachment fault are low angle and high ratio between heave and throw. The geometry of the detachment fault is a typical lisric shape, with the dip of fault decreasing generally from the seismic profile. The detachment basin where sediments are not deposited over a tilting hanging-wall block but onto a tectonically exhumed footwall which is different from the typical half graben basin. Seismic profiles indicate two different structural styles in the east and west part of Xingning-Jinghai sag. In the west of the sag, there developed two large detachment faults, which control their detachment basin systems and the typical H block, and the two detachment faults are dipping landward and seaward, respectively. In the east, affected by the later volcanic activities, Xingning-Jinghai sag deformed complicatedly and developed a series of landward dipping faults, showing the compound graben structure. Combined with the fault activity quantitative calculation, basin subsidence history and other advanced technology, the basin tectonic evolution has been divided into rift stage and post-rift stage. Considering the extension development evolution of Xingning-Jinghai sag and the extension and thinning of lithosphere under the background of spreading of the South China Sea, we argue that the northern margin of the South China lithosphere experienced an intense stretching and thinning stage. At this period, the subsidence of the Xingning-Jinghai sag was controlled by the detachment faults, indicating a rifting stage. With the development of the detachment faults, the thickness of crust was extremely thinned. After the spreading of the South China Sea the whole sag entered into the depression period which was characterized by thermal subsidence.

MIDDLE NORTH Series Pre-DICE THROW I, II and DICE THROW Test Execution Report

DTIC Science & Technology

1978-04-01

THROW 1 1- 14 1-10 Site Layout, 5 -Ton Events, Pre-DICE THROW I 1-16 1-11 Test Bed Layout - Pre-DICE THROW I 1-17 1-12 Airblast Gages and Instrumentation...111- 14 0-15 List of Tables (Cont’d) Table Page 3-3 Stacking Data 111-19 -22 3-4 Charge Weights 111-23 3- 5 ANFO Charge Summiary 111-23 3-6 Power...described in Table 1-1 and in Figures 1- 5 and 1-6 (these were detonated on 30 April, 14 May and 31 May 1975). Figures 1-7 and 1-8 show photographs of the ANFO

Tectonically controlled relief evolution in the Northern Tien Shan and Junggar Alatau from the Eocene to the Present

NASA Astrophysics Data System (ADS)

Seib, N.; Kley, J.; Voigt, T.; Kober, M.

2012-04-01

The Cenozoic Tien Shan and Junggar Alatau mountains developed on the southern part of the Paleozoic Altaid orogen as a far-field effect of the collision of the Indian and Eurasian plates. Highland terrain, active seismicity, and fast GPS-derived motions are evidence of rapid ongoing mountain growth today. Variations in relief energy, hight-to-width ratio of ranges and apatite fission track (AFT) exhumation ages suggest they rose at different times. The strong dissection of the higher ridges (heights of up to 2km), indicates an earlier onset and higher rates of uplift. At the other end of the spectrum are low, little dissected ridges. According to AFT ages, exhumation in the Junggar Range began at 9 Ma (Jolivet et al., 2010), circa 11 Ma in the central Kyrgyz Range (Sobel et al., 2006) and 10 Ma in the Terskey Alatau. An AFT age of the low Sogety range is 77 Ma, suggesting that the Cenozic exhumation of the ridge was insufficient to expose rocks from below c.3 km depth. The synclinal lows between the basement highs preserve Cenozoic strata of Eocene to Quaternary age, probably deposited in a once continuous basin (the Ili Basin) and recording the entire history of Tien Shan uplift. Facies pattern of proximal alluvial fans are strictly related to the recent higher mountain areas in the north and in the south. During Middle Miocene, a large lake developed in the basin center. Up to the Middle Miocene sedimentation was accompanied by normal faulting of small magnitude. The main Cenozoic folding and thrusting occurred after that time and before deposition of the Chorgos formation. Shortening was accommodated by reactivation of inherited basement structures, by a switch to reverse or strike-slip motion on normal faults, and the nucleation of new thrusts. The majority of faults which emplace basement rocks over upper Cenozoic sediments dip steeply at angles of 60-70˚, and some have throws of more than 200 m. They are marked by topographic steps and contrasting morphology across them. This first phase of deformation was followed by erosional leveling. Well-consolidated caliche layers indicate an extended period of stable soil formation in a (semi-)arid climate. Renewed shoting and uplift led to river incision and the formation of terraces and gave rise to new active faults, but their displacements are still low due to their short lifespans. These faults are presently expressed at the surface as fold scarps. The scarps are underlain by flexures affected in places by small thrust faults. Some of them, judging by their directions, are probably reactivating Miocene faults. The differences in the timing of range uplift, the progression of Cenozoic folding and the location of the young flexures all indicate migration of thrusting and folding from the borders of the Ili basin toward its center. A similar pattern of tectonic activity shifting from the flanking ridges toward the basin center was also observed in the Issyk-Kul basin (Korzhenkov, et al., 2007).

Earthquake geology and paleoseismology of major strands of the San Andreas fault system: Chapter 38

USGS Publications Warehouse

Rockwell, Thomas; Scharer, Katherine M.; Dawson, Timothy E.

2016-01-01

The San Andreas fault system in California is one of the best-studied faults in the world, both in terms of the long-term geologic history and paleoseismic study of past surface ruptures. In this paper, we focus on the Quaternary to historic data that have been collected from the major strands of the San Andreas fault system, both on the San Andreas Fault itself, and the major subparallel strands that comprise the plate boundary, including the Calaveras-Hayward- Rogers Creek-Maacama fault zone and the Concord-Green Valley-Bartlett Springs fault zone in northern California, and the San Jacinto and Elsinore faults in southern California. The majority of the relative motion between the Pacific and North American lithospheric plates is accommodated by these faults, with the San Andreas slipping at about 34 mm/yr in central California, decreasing to about 20 mm/yr in northern California north of its juncture with the Calaveras and Concord faults. The Calaveras-Hayward-Rogers Creek-Maacama fault zone exhibits a slip rate of 10-15 mm/yr, whereas the rate along the Concord-Green Valley-Bartlett Springs fault zone is lower at about 5 mm/yr. In southern California, the San Andreas exhibits a slip rate of about 35 mm/yr along the Mojave section, decreasing to as low as 10-15 mm/yr along its juncture with the San Jacinto fault, and about 20 mm/yr in the Coachella Valley. The San Jacinto and Elsinore fault zones exhibit rates of about 15 and 5 mm/yr, respectively. The average recurrence interval for surface-rupturing earthquakes along individual elements of the San Andreas fault system range from 100-500 years and is consistent with slip rate at those sites: higher slip rates produce more frequent or larger earthquakes. There is also evidence of short-term variations in strain release (slip rate) along various fault sections, as expressed as “flurries” or clusters of earthquakes as well as periods of relatively fewer surface ruptures in these relatively short records. This is reflected by non-periodic coefficients of variation in earthquake recurrence of 0.4 to 0.7 for the various paleoseismic sites.

Parent Use of DRI on High Rate Disruptive Behavior: Direct and Collateral Benefits.

ERIC Educational Resources Information Center

Friman, Patrick C.; Altman, Karl

1990-01-01

This study evaluates parental use of differential reinforcement of other and/or incompatible behavior to treat high-rate disruptive behavior in a severely retarded four-year-old boy. A withdrawal experimental design was used. Intervention effectively reduced instances of toy chewing and throwing, while appropriate toy play and ability to remain…

A testing-coverage software reliability model considering fault removal efficiency and error generation.

PubMed

Li, Qiuying; Pham, Hoang

2017-01-01

In this paper, we propose a software reliability model that considers not only error generation but also fault removal efficiency combined with testing coverage information based on a nonhomogeneous Poisson process (NHPP). During the past four decades, many software reliability growth models (SRGMs) based on NHPP have been proposed to estimate the software reliability measures, most of which have the same following agreements: 1) it is a common phenomenon that during the testing phase, the fault detection rate always changes; 2) as a result of imperfect debugging, fault removal has been related to a fault re-introduction rate. But there are few SRGMs in the literature that differentiate between fault detection and fault removal, i.e. they seldom consider the imperfect fault removal efficiency. But in practical software developing process, fault removal efficiency cannot always be perfect, i.e. the failures detected might not be removed completely and the original faults might still exist and new faults might be introduced meanwhile, which is referred to as imperfect debugging phenomenon. In this study, a model aiming to incorporate fault introduction rate, fault removal efficiency and testing coverage into software reliability evaluation is developed, using testing coverage to express the fault detection rate and using fault removal efficiency to consider the fault repair. We compare the performance of the proposed model with several existing NHPP SRGMs using three sets of real failure data based on five criteria. The results exhibit that the model can give a better fitting and predictive performance.

Fluid-injection and the mechanics of frictional stability of shale-bearing faults

NASA Astrophysics Data System (ADS)

Scuderi, Marco Maria; Collettini, Cristiano; Marone, Chris

2017-04-01

Fluid overpressure is one of the primary mechanisms for triggering tectonic fault slip and human-induced seismicity. This mechanism is appealing because fluids lubricate the fault and reduce the effective normal stress that holds the fault in place. However, current models of earthquake nucleation, based on rate- and state- friction, imply that stable sliding is favored by the increase of pore fluid pressure. Despite this apparent dilemma, there are a few studies on the role of fluid pressure in frictional stability under controlled, laboratory conditions. Here, we describe laboratory experiments on shale fault gouge, conducted in the double direct shear configuration in a true-triaxial machine. To characterize frictional stability and hydrological properties we performed three types of experiments: 1) stable sliding shear experiment to determine the material failure envelope resulting in fault strength of µ=0.28 and fault zone permeability (k 10-19m2); 2) velocity step experiments to determine the rate- and state- frictional properties, characterized by a velocity strengthening behavior with a negative rate parameter b, indicative of stable aseismic creep; 3) creep experiment to study fault slip evolution with increasing pore-fluid pressure. In these creep experiments fault slip history can be divided in three main stages: a) for low fluid pressure the fault is locked and undergoes compaction; b) with increasing fluid pressurization, we observe aseismic creep (i.e. v=0.0001 µm/s) associated with fault dilation, with maintained low permeability; c) As fluid pressure is further increased and we approach the failure criteria fault begins to accelerate, the dilation rate increases causing an increase in permeability. Following the first acceleration we document complex fault slip behavior characterized by periodic accelerations and decelerations with slip velocity that remains slow (i.e. v 200 µm/s), never approaching dynamic slip rates. Surprisingly, this complex slip behavior is associated with fault zone compaction and permeability increase as opposite to the dilation hardening mechanism that is usually invoked to quench the instability. We relate this complex fault slip behaviour to the interplay between fault weakening induced by fluid pressurization and the strong rate-strengthening behaviour of shales. Our data show that fault rheology and fault stability is controlled by the coupling between fluid pressure and rate- and state- friction parameters suggesting that their comprehensive characterization is fundamental for assessing the role of fluid pressure in natural and human induced earthquakes.

Displacement rates on the Toroweap and Hurricane faults: implications for Quaternary downcutting in the Grand Canyon, Arizona

USGS Publications Warehouse

Fenton, Cassandra R.; Webb, Robert H.; Pearthree, Philip A.; Cerling, Thure E.; Poreda, Robert J.

2001-01-01

The Toroweap and Hurricane faults, considered to be the most active in Arizona, cross the Uinkaret volcanic field in the western Grand Canyon. These normal faults are downthrown to the west, and the Colorado River crosses these faults as it flows west in the Grand Canyon. Cosmogenic 3He (3Hec) dates on basalt flows and related landforms are used to calculate vertical displacement rates for these faults. The two faults cross unruptured alluvial fans dated as 3 ka (Toroweap) and 8 ka (Hurricane), and 10 other landforms that range in age from 30 to 400 ka are displaced. Middle and late Quaternary displacement rates of the Toroweap and Hurricane faults are 70–180 and 70–170 m/m.y., respectively. On the basis of these rates, the combined displacement of 580 m on these faults could have occurred in the past 3 to 5 m.y. All 3Hec dates are younger than existing K- Ar dates and are consistent with new 40Ar/39Ar dates and existing thermoluminescence (TL) dates on basalt flows. These different dating techniques may be combined in an analysis of displacement rates. Downcutting rates for the Colorado River in the eastern Grand Canyon (400 m/m.y.) are at least double the downcutting rates west of the faults (70–160 m/m.y.). Faulting probably increased downcutting in the eastern Grand Canyon relative to downcutting in the western Grand Canyon during the late Quaternary.

Association of eye color and sex with basketball free throws by elementary school children.

PubMed

Patee, T; Frewen, M; Beer, J

1991-12-01

Dark-eyed individuals perform reactive activities better while light-eyed individuals generally perform self-paced activities better. There were 68 (21 dark- and 47 light-eyed) elementary school children who shot 5 practice and then 15 free throws from the free-throw line in a high school gym. There were no differences in performance between light- and dark-eyed children, but boys scored more free throws than girls.

Cenozoic evolution of the Socotra Island: opening of the Gulf of Aden

NASA Astrophysics Data System (ADS)

Razin, P.; Robin, C.; Serra Kiel, J.; Leroy, S.; Bellahsen, N.; Khanbari, K.

2009-12-01

A complete stratigraphic and geological map revision of the Tertiary of Socotra Island is undertaken in order to better characterize the geometry and the tecto-sedimentary evolution of the southern margin of the Gulf of Aden, and compare them with those of the conjugate northern margin in Oman. An increase of the rate of subsidence is recorded during the Late Eocene and is associated with a transgressive peak within carbonate platform deposits (Aydim Fm.). At the scale of the Arabian plate, the extent of this platform is reduced to the future rift area. This evolution of the platform system shows a modification of the sedimentary profiles, controlled by the beginning of the rifting. The syn-rift deposits of the Early Oligocene correspond to sub-reef carbonate platform facies (Ashawq Fm.). First, the throw of synsedimentary faults and the movements linked with differential subsidence are widely compensated by carbonate production which manages to maintain a platform profile. These movements are recorded by thickness variations, significant lateral variations in the platform facies and by a local inversion of sedimentary polarities controlled by the tilting of faulted blocks. Like on the northern margin, an acceleration of the extension process leads, during the Late Oligocene, to a collapse of the platform and to the creation of deep sub-basins with carbonate gravity-flow sedimentation. Marginal reef platforms keep growing at this stage on the structural highs and feed gravity-flow sedimentary systems. The sedimentation rate stays then relatively low in the basin, forming a complex topography of the margin, marked by a segmentation into numerous sub-basins more or less connected and separated by submarine escarpments marked by wedges of breccia deposits along active normal faults. In different points, these faults are sealed by sedimentary deposits characterized by progressive unconformities and onlap geometries on the fault escarpments. These geometries show the relatively short length of the phase of « stretching » of the continental crust. Around the end of the Early Miocene, the progradation of conglomerate fan-delta deposits locally results in the fill of the basins and shows a major phase of uplift. It is very rapidly followed by a new phase of subsidence which allows the preservation of thick fan-delta and equivalent reef platform complex unconformably overlying different units of the syn-rift and pre-rift sequences, or even the exhumed Proterozoic basement. This tectonic-sedimentary phase is interpreted as synchronous to the continental breakup and the onset of the OCT at the foot of the margin. The analogy with the phase of development of «sag basins» on the Atlantic margins has to be analyzed. This major uplift at the transition syn-rift/post-rift seems to be expressed symmetrically on both margins. These syn-OCT deposits are then uplifted and affected by late tilting events. However, the most recent deposits, probably Late Miocene to plio-Quaternary in age, have only been affected by small uplifts, unlike those of the Dhofar on the northern margin

A fault‐based model for crustal deformation in the western United States based on a combined inversion of GPS and geologic inputs

USGS Publications Warehouse

Zeng, Yuehua; Shen, Zheng-Kang

2017-01-01

We develop a crustal deformation model to determine fault‐slip rates for the western United States (WUS) using the Zeng and Shen (2014) method that is based on a combined inversion of Global Positioning System (GPS) velocities and geological slip‐rate constraints. The model consists of six blocks with boundaries aligned along major faults in California and the Cascadia subduction zone, which are represented as buried dislocations in the Earth. Faults distributed within blocks have their geometrical structure and locking depths specified by the Uniform California Earthquake Rupture Forecast, version 3 (UCERF3) and the 2008 U.S. Geological Survey National Seismic Hazard Map Project model. Faults slip beneath a predefined locking depth, except for a few segments where shallow creep is allowed. The slip rates are estimated using a least‐squares inversion. The model resolution analysis shows that the resulting model is influenced heavily by geologic input, which fits the UCERF3 geologic bounds on California B faults and ±one‐half of the geologic slip rates for most other WUS faults. The modeled slip rates for the WUS faults are consistent with the observed GPS velocity field. Our fit to these velocities is measured in terms of a normalized chi‐square, which is 6.5. This updated model fits the data better than most other geodetic‐based inversion models. Major discrepancies between well‐resolved GPS inversion rates and geologic‐consensus rates occur along some of the northern California A faults, the Mojave to San Bernardino segments of the San Andreas fault, the western Garlock fault, the southern segment of the Wasatch fault, and other faults. Off‐fault strain‐rate distributions are consistent with regional tectonics, with a total off‐fault moment rate of 7.2×1018">7.2×1018 and 8.5×1018  N·m/year">8.5×1018  N⋅m/year for California and the WUS outside California, respectively.

The vertical slip rate of the Sertengshan piedmont fault, Inner Mongolia, China

NASA Astrophysics Data System (ADS)

Zhang, Hao; He, Zhongtai; Ma, Baoqi; Long, Jianyu; Liang, Kuan; Wang, Jinyan

2017-08-01

The vertical slip rate of a normal fault is one of the most important parameters for evaluating its level of activity. The Sertengshan piedmont fault has been studied since the 1980s, but its absolute vertical slip rate has not been determined. In this paper, we calculate the displacements of the fault by measuring the heights of piedmont terraces on the footwall and the stratigraphic depths of marker strata in the hanging wall. We then calculate the vertical slip rate of the fault based on the displacements and ages of the marker strata. We selected nine sites uniformly along the fault to study the vertical slip rates of the fault. The results show that the elevations of terraces T3 and T1 are approximately 1060 m and 1043 m, respectively. The geological boreholes in the basin adjacent to the nine study sites reveal that the elevation of the bottom of the Holocene series is between 1017 and 1035 m and that the elevation of the top of the lacustrine strata is between 925 and 1009 m. The data from the terraces and boreholes also show that the top of the lacustrine strata is approximately 65 ka old. The vertical slip rates are calculated at 0.74-1.81 mm/a since 65 ka and 0.86-2.28 mm/a since the Holocene. The slip rate is the highest along the Wujiahe segment and is lower to the west and east. Based on the findings of a previous study on the fault system along the northern margin of the Hetao graben basin, the vertical slip rates of the Daqingshan and Langshan faults are higher than those of the Sertengshan and Wulashan faults, and the strike-slip rates of these four northern Hetao graben basin faults are low. These results agree with the vertical slip components of the principal stress field on the faults. The results of our analysis indicate that the Langshankou, Wujiahe, and Wubulangkou areas and the eastern end of the Sertengshan fault are at high risk of experiencing earthquakes in the future.

A biomechanical study of laparoscopic 4S-modified Roeder and Weston knot strength in 3-0 polyglactin 910 and 3-0 polydioxanone.

PubMed

Fugazzi, Russell W; Fransson, Boel A; Curran, Katie M; Davis, Howard M; Gay, John M

2013-02-01

To (1) evaluate biomechanical strength of 4 different laparoscopic knots using 2 suture types, and (2) evaluate carotid artery ligature bursting pressure of 2 knots using a single suture type. Biomechanical materials testing. Suture material (3-0 polydioxanone, 3-0 polyglactin 910). Four knot types were tested: 4S-modified Roeder (4SMR) Weston plus 3 square throws (W3S); Weston plus 3 granny throws (W3G); and a 4 square throw knot as a control (control); 24 specimens of each knot type were tied with 3-0 polyglactin 910 and 24 of 3 knot types (4SMR, W3S, control) were tied with 3-0 polydioxanone. Suture loop constructs were tested to 3 mm displacement failure and ultimate failure. Carotid artery ligation bursting pressure was tested using 10 samples each of 4SMR and W3S knots with 3-0 polyglactin 910. The W3S, W3G, and controls were similar. The 4SMR was similar to W3S using 3-0 PDS but the 4SMR had lower load to failure and greater elongation than the Weston using 3-0 polyglactin 910. The 4SMR had a higher slippage rate with 3-0 polyglactin 910. All ligatures withstood supraphysiologic pressures. Surgeons using 3-0 polyglactin 910 should consider using the Weston knot with added throws during laparoscopic procedures. © Copyright 2012 by The American College of Veterinary Surgeons.

Rest Interval Required for Power Training With Power Load in the Bench Press Throw Exercise.

PubMed

Hernández Davó, Jose L; Solana, Rafael Sabido; Sarabia Marín, Jose M; Fernández Fernández, Jaime; Moya Ramón, Manuel

2016-05-01

This study aimed to test the influence of various rest interval (RI) durations used between sets on power output performance and physiological and perceptual variables during a strength training session using 40% of the 1 repetition maximum (1RM) in the bench press throw exercise. Thirty-one college students (18 males and 13 females) took part in the study. The experimental protocol consists of 5 sets of 8 repetitions of the bench press throw exercise with a load representing 40% of 1RM. Subjects performed the experimental protocol on 3 different occasions, differing by the RI between sets (1, 2, or 3 minutes). During the sessions, power data (mean power and peak power), physiological (lactate concentration [La]) and perceptual (rating of perceived exertion) variables were measured. In addition, delayed onset muscular soreness was reported 24 and 48 hours after the training session. One-way repeated-measures analysis of variance showed that 1-minute RI entailed higher power decreases and greater increases in values of physiological and perceptual variables compared with both 2- and 3-minute RIs. Nevertheless, no differences were found between 2- and 3-minute RIs. Therefore, this study showed that, when training with 40% of 1RM in the bench press throw exercise, a 2-minute RI between sets can be enough to avoid significant decreases in power output. Consequently, training sessions' duration could be reduced without causing excessive fatigue, allowing additional time to focus on other conditioning priorities.

Modelling effects of tree population dynamics, tree throw and pit-mound formation/diffusion on microtopography over time in different forest settings

NASA Astrophysics Data System (ADS)

Martin, Y. E.; Johnson, E. A.; Gallaway, J.; Chaikina, O.

2011-12-01

Herein we conduct a followup investigation to an earlier research project in which we developed a numerical model of tree population dynamics, tree throw, and sediment transport associated with the formation of pit-mound features for Hawk Creek watershed, Canadian Rockies (Gallaway et al., 2009). We extend this earlier work by exploring the most appropriate transport relations to simulate the diffusion over time of newly-formed pit-pound features due to tree throw. We combine our earlier model with a landscape development model that can incorporate these diffusive transport relations. Using these combined models, changes in hillslope microtopography over time associated with the formation of pit-mound features and their decay will be investigated. The following ideas have motivated this particular study: (i) Rates of pit-mound degradation remain a source of almost complete speculation, as there is almost no long-term information on process rates. Therefore, we will attempt to tackle the issue of pit-mound degradation in a methodical way that can guide future field studies; (ii) The degree of visible pit-mound topography at any point in time on the landscape is a joint function of the rate of formation of new pit-mound features due to tree death/topple and their magnitude vs. the rate of decay of pit-mound features. An example of one interesting observation that arises is the following: it appears that pit-mound topography is often more pronounced in some eastern North American forests vs. field sites along the eastern slopes of the Canadian Rockies. Why is this the case? Our investigation begins by considering whether pit-mound decay might occur by linear or nonlinear diffusion. What differences might arise depending on which diffusive approach is adopted? What is the magnitude of transport rates associated with these possible forms of transport relations? We explore linear and nonlinear diffusion at varying rates and for different sizes of pit-mound pairs using a numerical modelling approach. Model results suggest that longevity of pit-mound features is dependent on: (i) magnitude/dimensions of initial pit-mound features for forests in different regions; (ii) defining appropriate pit-mound diffusion rates for these different forests (unfortunately, almost no appropriate field observations exist for calibration of these transport relations). In the next stage of this research, we will combine our earlier model of forest disturbance/tree population dynamics, tree throw and pit-mound formation with the numerical model LandMod (Martin, 1998, 2000, 2007); the latter will be used to simulate pit-mound diffusion over time. In this way, we can observe changes in hillslope microtopographic signatures over time that are found in different forest settings.

A comparison of peak power in the shoulder press and shoulder throw.

PubMed

Dalziel, W M; Neal, R J; Watts, M C

2002-09-01

The ability to generate peak power is central for performance in many sports. Currently two distinct resistance training methods are used to develop peak power, the heavy weight/slow velocity and light weight/fast velocity regimes. When using the light weight/fast velocity power training method it was proposed that peak power would be greater in a shoulder throw exercise compared with a normal shoulder press. Nine males performed three lifts in the shoulder press and shoulder throw at 30% and 40% of their one repetition maximum (1RM). These lifts were performed identically, except for the release of the bar in the throw condition. A potentiometer attached to the bar measured displacement and duration of the lifts. The time of bar release in the shoulder throw was determined with a pressure switch. ANOVA was used to examine statistically significant differences where the level of acceptance was set at p < 0.05. Peak power was found to be significantly greater in the shoulder throw at 30% of 1 RM condition [F, (1, 23) = 2.325 p < 0.051 and at 40% of 1 RM [F, (1, 23) = 2.905 p < 0.05] compared to values recorded for the respective shoulder presses. Peak power was also greater in the 30% of 1 RM shoulder throw (510 +/- 103W) than in the 40% of 1 RM shoulder press (471 +/- 96W). Peak power was produced significantly later in the shoulder throw versus the shoulder press. This differing power reflected a greater bar velocity of the shoulder throw at both assigned weights compared with the shoulder press.

Performance enhancement among adolescent players after 10 weeks of pitching training with appropriate baseball weights.

PubMed

Yang, Wen-Wen; Liu, Ya-Chen; Lu, Lee-Chang; Chang, Hsiao-Yun; Chou, Paul Pei-Hsi; Liu, Chiang

2013-12-01

Compared with regulation-weight baseballs, lightweight baseballs generate lower torque on the shoulder and elbow joints without altering the pitching movement and timing. This study investigates the throwing accuracy, throwing velocity, arm swing velocity, and maximum shoulder external rotation (MSER) of adolescent players after 10 weeks of pitching training with appropriate lightweight baseballs. We assigned 24 adolescent players to a lightweight baseball group (group L) and a regulation-weight baseball group (group R) based on their pretraining throwing velocity. Both groups received pitching training 3 times per week for 10 weeks with 4.4- and 5-oz baseballs. The players' throwing accuracy, throwing velocity, arm swing velocity, and MSER were measured from 10 maximum efforts throws using a regulation-weight baseball before and after undergoing the pitching training. The results showed that the players in group L significantly increased their throwing velocity and arm swing velocity (p < 0.05) after 10 weeks of pitching training with the 4.4-oz baseball, whereas group R did not (p > 0.05). Furthermore, the percentage change in the throwing velocity and arm swing velocity of group L was significantly superior to that of group R (p < 0.05). Thus, we concluded that the 10 weeks of pitching training with an appropriate lightweight baseball substantially enhanced the arm swing velocity and throwing velocity of the adolescent baseball players. These findings suggest that using a lightweight baseball, which can reduce the risk of injury without altering pitching patterns, has positive training effects on players in the rapid physical growth and technique development stage.

Release parameters at the foul line and the official result in javelin throwing.

PubMed

Viitasalo, Jukka; Mononen, Harri; Norvapalo, Kare

2003-01-01

Range in javelin throwing is determined by the release parameters and aerodynamic factors. The current study was designed to investigate the effects of release speed, release angle and uncorrected angle of attack measured at the foul line on the official javelin throwing result. The data were collected in international competitions for 26 elite male and 15 elite female javelin throwers (total 248 throws). Multiple regression models were constructed to predict the range of throw for a) individual throwers, b) a group of throwers using the mean value for each thrower in the analysis, and c) all individual throws registered for each gender separately. The data collection was carried out using a computerised photocell gate that consists of two invisible infrared walls two metres apart, perpendicular to the throwing direction. Release speed was found to have the highest correlation with the official throwing result. The three release parameters accounted for 56% of the variance in the official result for the male and 51% for the female throwers. For individual male and female throwers, the variance explained by the model was between 46 and 87%. Among the individual male throwers an increase of 1 m.s-1 in the release speed from 29 to 30 m.s-1 was calculated to increase the official result between 2.12 to 6.14 m while among the female throwers the effect of increase from 24 to 25 m.s-1 in the release speed was from 2.25 to 3.68 m. The study emphasises the importance of investigating javelin throwing biomechanics on an individual thrower basis.

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

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.

Irregular earthquake recurrence patterns and slip variability on a plate-boundary Fault

NASA Astrophysics Data System (ADS)

Wechsler, N.; Rockwell, T. K.; Klinger, Y.

2015-12-01

The Dead Sea fault in the Levant represents a simple, segmented plate boundary from the Gulf of Aqaba northward to the Sea of Galilee, where it changes its character into a complex plate boundary with multiple sub-parallel faults in northern Israel, Lebanon and Syria. The studied Jordan Gorge (JG) segment is the northernmost part of the simple section, before the fault becomes more complex. Seven fault-crossing buried paleo-channels, offset by the Dead Sea fault, were investigated using paleoseismic and geophysical methods. The mapped offsets capture the long-term rupture history and slip-rate behavior on the JG fault segment for the past 4000 years. The ~20 km long JG segment appears to be more active (in term of number of earthquakes) than its neighboring segments to the south and north. The rate of movement on this segment varies considerably over the studied period: the long-term slip-rate for the entire 4000 years is similar to previously observed rates (~4 mm/yr), yet over shorter time periods the rate varies from 3-8 mm/yr. Paleoseismic data on both timing and displacement indicate a high COV >1 (clustered) with displacement per event varying by nearly an order of magnitude. The rate of earthquake production does not produce a time predictable pattern over a period of 2 kyr. We postulate that the seismic behavior of the JG fault is influenced by stress interactions with its neighboring faults to the north and south. Coulomb stress modelling demonstrates that an earthquake on any neighboring fault will increase the Coulomb stress on the JG fault and thus promote rupture. We conclude that deriving on-fault slip-rates and earthquake recurrence patterns from a single site and/or over a short time period can produce misleading results. The definition of an adequately long time period to resolve slip-rate is a question that needs to be addressed and requires further work.

Quaternary Basalts in Grand Canyon: Correlation of Flows Using Lidar, 40Ar/39Ar Dating, Geochemical Correlation, Neotectonic Studies, and History of Lava Dams

NASA Astrophysics Data System (ADS)

Crow, R. S.; Karlstrom, K. E.; McIntosh, W. C.; Dunbar, N. W.; Peters, L.; Raucci, J.; Umhoefer, P. J.

2005-12-01

In western Grand Canyon, basalts flowed into the already existing canyon from at least 719 ka to present. These basalts provide a key for deciphering Quaternary rates of incision, neotectonic slip rates on the Toroweap and Hurricane faults, and the history of lava dams. Stratigraphy and/or inset relationships between basalt flows is exceedingly complex because of the multiple eruptions, extreme topography, long transport distance, and incomplete preservation. Correlation of flows using 40Ar/39Ar dating, LIDAR data, orthophotography, and geochemical analysis, as well as structural and geomorphic studies, lead to a working hypothesis for four major episodes of basaltic eruptive activity. From 719 to 484 Ma major volcanoes erupted near the Toroweap fault zone. The extent of the remnants and presence of 527 ka dikes indicates that cones where built within Grand Canyon during this phase. These flows had the longest outflow (719 ka flow at mile 246). At 349 to 296 ka flows seem to have entered the canyon at Whitmore Wash, north rim. The two remaining episodes, dated at 199-193 ka and 109-97 ka are interpreted to have cascaded into the canyon at and upstream from Whitmore Wash. LIDAR/orthophotography interpretation of the tops and bottoms of the flows and geochemical analysis of phenocrysts aid in correlation of undated remnants and reconstructing the shape of volcanic edifices. Flows dated from 720-450 ka include Prospect, Black Ledge, D-Dam, and Toroweap flows, thus Black Ledge flows are considerably older than previously thought. The 350 to 300 flows include Whitmore, Layered Diabase, Massive Diabase, and 177-mile flows. All the dated 200 and 100 ka flows have been called Grey Ledge flows, suggesting that the Grey Ledge represents two distinct events. Basalt data indicate an interaction of canyon incision and Quaternary fault slip. Bedrock incision rates are calculated using dated flows that overly bedrock straths. Rates vary across active faults indicating fault dampening of apparent river incision rates. Incision rates for eastern Grand Canyon are 127 m/my over 387 ka. Similar rates just east of the Toroweap faults (136 m/my over 349 ka and 153 m/my over 484 ka) suggest that a fairly uniform regional rate of ~ 140 m/my can be considered the average rate for Grand Canyon incision east of the Toroweap fault. This is subequal to the sum of apparent incision rate just below the Toroweap fault (56 m/my over 484 ka) plus fault slip rate (90 m/my over 550 ka). Similarly, apparent incision rates below the Hurricane fault (66 m/my over 527 ka and 76 m/my over 604 ka, near Granite Park) plus fault slip rate (~80±20 m/my over 185 ka) is subequal to the far field incision rate. Accumulating data suggests that apparent incision rates are lowest adjacent to faults in the hanging wall and highest adjacent to faults in the footwall, with rates varying systematically across fault blocks. This suggests that faulting is taking place by domino rotation of blocks bounded by normal faults with mild listric character. These new empirical data help constrain physical models for Quaternary fault slip across the active Colorado Plateau- Basin and Range bounding structures.

Fault detection and diagnosis for refrigerator from compressor sensor

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

Keres, Stephen L.; Gomes, Alberto Regio; Litch, Andrew D.

A refrigerator, a sealed refrigerant system, and method are provided where the refrigerator includes at least a refrigerated compartment and a sealed refrigerant system including an evaporator, a compressor, a condenser, a controller, an evaporator fan, and a condenser fan. The method includes monitoring a frequency of the compressor, and identifying a fault condition in the at least one component of the refrigerant sealed system in response to the compressor frequency. The method may further comprise calculating a compressor frequency rate based upon the rate of change of the compressor frequency, wherein a fault in the condenser fan is identifiedmore » if the compressor frequency rate is positive and exceeds a condenser fan fault threshold rate, and wherein a fault in the evaporator fan is identified if the compressor frequency rate is negative and exceeds an evaporator fan fault threshold rate.« less

Distribution of aseismic slip rate on the Hayward fault inferred from seismic and geodetic data

USGS Publications Warehouse

Schmidt, D.A.; Burgmann, R.; Nadeau, R.M.; d'Alessio, M.

2005-01-01

We solve for the slip rate distribution on the Hayward fault by performing a least squares inversion,of geodetic and seismic data sets. Our analysis focuses on the northern 60 km of the fault. Interferometric synthetic aperture radar (InSAR) data from 13 independent ERS interferograms are stacked to obtain range change rates from 1992 to 2000. Horizontal surface displacement rates at 141 bench marks are measured using GPS from 1994 to 2003. Surface creep observations and estimates of deep slip rates determined from characteristic repeating earthquake sequences are also incorporated in the inversion. The fault is discretized into 283 triangular dislocation elements that approximate the nonplanar attributes of the fault surface. South of the city of Hayward, a steeply, east dipping fault geometry accommodates the divergence of the surface trace and the microseismicity at depth. The inferred slip rate distribution is consistent with a fault that creeps aseismically at a rate of ???5 mm/yr to a depth of 4-6 km. The interferometric synthetic aperture radar (InSAR) data require an aseismic slip rate that approaches the geologic slip rate on the northernmost fault segment beneath Point Pinole, although the InSAR data might be complicated by a small dip-slip component at this location. A low slip rate patch of <1 mm/yr is inferred beneath San Leandro consistent with the source location of the 1868 earthquake. We calculate that the entire fault is accumulating a slip rate deficit equivalent to a Mw = 6.77 ?? 0.05 per century. However, this estimate of potential coseismic moment represents an upper bound because we do not know how much of the accumulated strain will be released through aseismic processes such as afterslip. Copyright 2005 by the American Geophysical Union.

Controls on Cenozoic exhumation of the Tethyan Himalaya from fission-track thermochronology and detrital zircon U-Pb geochronology in the Gyirong basin area, southern Tibet

NASA Astrophysics Data System (ADS)

Shen, Tianyi; Wang, Guocan; Leloup, Philippe Hervé; van der Beek, Peter; Bernet, Matthias; Cao, Kai; Wang, An; Liu, Chao; Zhang, Kexin

2016-07-01

The Gyirong basin, southern Tibet, contains the record of Miocene-Pliocene exhumation, drainage development, and sedimentation along the northern flank of the Himalaya. The tectonic controls on basin formation and their potential link to the South Tibetan Detachment System (STDS) are not well understood. We use detrital zircon (ZFT) and apatite (AFT) fission-track analysis, together with detrital zircon U-Pb dating to decipher the provenance of Gyirong basin sediments and the exhumation history of the source areas. Results are presented for nine detrital samples of Gyirong basin sediments (AFT, ZFT, and U-Pb), two modern river-sediment samples (ZFT and AFT), and six bedrock samples (ZFT) from transect across the Gyirong fault bounding the basin to the east. The combination of detrital zircon U-Pb and fission-track data demonstrates that the Gyirong basin sediments were sourced locally from the Tethyan Sedimentary Sequence. This provenance pattern indicates that deposition was controlled by the Gyirong fault, active since 10 Ma, whose vertical throw was probably < 5000 m, rather than being controlled by normal faults associated with the STDS. The detrital thermochronology data contain two prominent age groups at 37-41 and 15-18 Ma, suggesting rapid exhumation at these times. A 15-18 Ma phase of rapid exhumation has been recorded widely in both southern Tibet and the Himalaya. A possible interpretation for such a major regional exhumation event might be detachment of the subducting Indian plate slab during the middle Miocene, inducing dynamic uplift of the Indian plate overriding its own slab.

A testing-coverage software reliability model considering fault removal efficiency and error generation

PubMed Central

Li, Qiuying; Pham, Hoang

2017-01-01

In this paper, we propose a software reliability model that considers not only error generation but also fault removal efficiency combined with testing coverage information based on a nonhomogeneous Poisson process (NHPP). During the past four decades, many software reliability growth models (SRGMs) based on NHPP have been proposed to estimate the software reliability measures, most of which have the same following agreements: 1) it is a common phenomenon that during the testing phase, the fault detection rate always changes; 2) as a result of imperfect debugging, fault removal has been related to a fault re-introduction rate. But there are few SRGMs in the literature that differentiate between fault detection and fault removal, i.e. they seldom consider the imperfect fault removal efficiency. But in practical software developing process, fault removal efficiency cannot always be perfect, i.e. the failures detected might not be removed completely and the original faults might still exist and new faults might be introduced meanwhile, which is referred to as imperfect debugging phenomenon. In this study, a model aiming to incorporate fault introduction rate, fault removal efficiency and testing coverage into software reliability evaluation is developed, using testing coverage to express the fault detection rate and using fault removal efficiency to consider the fault repair. We compare the performance of the proposed model with several existing NHPP SRGMs using three sets of real failure data based on five criteria. The results exhibit that the model can give a better fitting and predictive performance. PMID:28750091

Dual-gate GaAs FET switches

NASA Astrophysics Data System (ADS)

Vorhaus, J. L.; Fabian, W.; Ng, P. B.; Tajima, Y.

1981-02-01

A set of multi-pole, multi-throw switch devices consisting of dual-gate GaAs FET's is described. Included are single-pole, single-throw (SPST), double-pole, double-throw (DPDT), and single-pole four-throw (SP4T) switches. Device fabrication and measurement techniques are discussed. The device models for these switches were based on an equivalent circuit of a dual-gate FET. The devices were found to have substantial gain in X-band and low Ku-band.

Reliability and validity of a talent identification test battery for seated and standing Paralympic throws.

PubMed

Spathis, Jemima Grace; Connick, Mark James; Beckman, Emma Maree; Newcombe, Peter Anthony; Tweedy, Sean Michael

2015-01-01

Paralympic throwing events for athletes with physical impairments comprise seated and standing javelin, shot put, discus and seated club throwing. Identification of talented throwers would enable prediction of future success and promote participation; however, a valid and reliable talent identification battery for Paralympic throwing has not been reported. This study evaluates the reliability and validity of a talent identification battery for Paralympic throws. Participants were non-disabled so that impairment would not confound analyses, and results would provide an indication of normative performance. Twenty-eight non-disabled participants (13 M; 15 F) aged 23.6 years (±5.44) performed five kinematically distinct criterion throws (three seated, two standing) and nine talent identification tests (three anthropometric, six motor); 23 were tested a second time to evaluate test-retest reliability. Talent identification test-retest reliability was evaluated using Intra-class Correlation Coefficient (ICC) and Bland-Altman plots (Limits of Agreement). Spearman's correlation assessed strength of association between criterion throws and talent identification tests. Reliability was generally acceptable (mean ICC = 0.89), but two seated talent identification tests require more extensive familiarisation. Correlation strength (mean rs = 0.76) indicated that the talent identification tests can be used to validly identify individuals with competitively advantageous attributes for each of the five kinematically distinct throwing activities. Results facilitate further research in this understudied area.

THORACOLUMBAR RANGE OF MOTION IN BASEBALL PITCHERS AND POSITION PLAYERS

PubMed Central

Lynall, Robert; Williams, Jeffrey G.; Wong, Regan; Onuki, Takashi; Meister, Keith

2013-01-01

Introduction/Background: Optimal baseball throwing mechanics require a significant contribution of thoracolumbar motion, particularly in the sagittal and transverse planes. This motion is key for proper transmission of forces from the lower to upper extremity, thereby minimizing a throwing athlete's risk of injury and maximizing athletic performance. Purpose: To define the active‐assisted thoracolumbar ROM of both baseball pitchers and position players and to compare these motions both within and between groups. Methods: Fifty‐six asymptomatic, collegiate and minor league baseball pitchers and 42 position players volunteered to participate. Active‐assisted thoracolumbar flexion, extension, and bilateral rotation ROM, were measured in a standing position, using two bubble inclinometers. Two‐tailed t tests were used to determine differences in ROM between and within the pitchers and position players. Results: The pitchers had significantly more rotation to the non‐throwing arm side as compared to the position players (p = .007, effect size = .61). The pitchers also had more rotation to the non‐throwing arm side as compared to their throwing side (p = .006, effect size = .47). There were no other significant differences between the pitchers and the position players (p > .53). Furthermore, the position players did not have a side‐to‐side rotation difference (p = .99). Conclusions: Pitchers have a greater amount of rotation ROM towards the non‐throwing arm side as compared to position players. Pitchers also have a greater amount of rotation ROM to the non‐throwing arm side as compared to their throwing side rotation. Because pitchers often present with posterior shoulder tightness and subsequent altered shoulder horizontal adduction and internal rotation ROM, the increase in non‐throwing side rotation ROM may occur in response to these adaptations. More specifically, this increase in non‐throwing side trunk rotation ROM may allow such athletes to bring the arm across the body during the follow‐through phase of the throwing motion despite posterior shoulder tightness. However, future research is necessary to investigate this relationship. Based on these results, clinicians should consider these thoracolumbar ROM adaptations in the prevention, evaluation, and treatment of baseball players. Level of Evidence: 2b PMID:24377063

Slip distribution, strain accumulation and aseismic slip on the Chaman Fault system

NASA Astrophysics Data System (ADS)

Amelug, F.

2015-12-01

The Chaman fault system is a transcurrent fault system developed due to the oblique convergence of the India and Eurasia plates in the western boundary of the India plate. To evaluate the contemporary rates of strain accumulation along and across the Chaman Fault system, we use 2003-2011 Envisat SAR imagery and InSAR time-series methods to obtain a ground velocity field in radar line-of-sight (LOS) direction. We correct the InSAR data for different sources of systematic biases including the phase unwrapping errors, local oscillator drift, topographic residuals and stratified tropospheric delay and evaluate the uncertainty due to the residual delay using time-series of MODIS observations of precipitable water vapor. The InSAR velocity field and modeling demonstrates the distribution of deformation across the Chaman fault system. In the central Chaman fault system, the InSAR velocity shows clear strain localization on the Chaman and Ghazaband faults and modeling suggests a total slip rate of ~24 mm/yr distributed on the two faults with rates of 8 and 16 mm/yr, respectively corresponding to the 80% of the total ~3 cm/yr plate motion between India and Eurasia at these latitudes and consistent with the kinematic models which have predicted a slip rate of ~17-24 mm/yr for the Chaman Fault. In the northern Chaman fault system (north of 30.5N), ~6 mm/yr of the relative plate motion is accommodated across Chaman fault. North of 30.5 N where the topographic expression of the Ghazaband fault vanishes, its slip does not transfer to the Chaman fault but rather distributes among different faults in the Kirthar range and Sulaiman lobe. Observed surface creep on the southern Chaman fault between Nushki and north of City of Chaman, indicates that the fault is partially locked, consistent with the recorded M<7 earthquakes in last century on this segment. The Chaman fault between north of the City of Chaman to North of Kabul, does not show an increase in the rate of strain accumulation. However, lack of seismicity on this segment, presents a significant hazard on Kabul. The high rate of strain accumulation on the Ghazaband fault and lack of evidence for the rupture of the fault during the 1935 Quetta earthquake, present a growing earthquake hazard to the Balochistan and the populated areas such as the city of Quetta.

InSAR observations of strain accumulation and fault creep along the Chaman Fault system, Pakistan and Afghanistan

NASA Astrophysics Data System (ADS)

Fattahi, Heresh; Amelung, Falk

2016-08-01

We use 2004-2011 Envisat synthetic aperture radar imagery and InSAR time series methods to estimate the contemporary rates of strain accumulation in the Chaman Fault system in Pakistan and Afghanistan. At 29 N we find long-term slip rates of 16 ± 2.3 mm/yr for the Ghazaband Fault and of 8 ± 3.1 mm/yr for the Chaman Fault. This makes the Ghazaband Fault one of the most hazardous faults of the plate boundary zone. We further identify a 340 km long segment displaying aseismic surface creep along the Chaman Fault, with maximum surface creep rate of 8.1 ± 2 mm/yr. The observation that the Chaman Fault accommodates only 30% of the relative plate motion between India and Eurasia implies that the remainder is accommodated south and east of the Katawaz block microplate.

Southeastward increase of the late Quaternary slip-rate of the Xianshuihe fault, eastern Tibet. Geodynamic and seismic hazard implications

NASA Astrophysics Data System (ADS)

Bai, Mingkun; Chevalier, Marie-Luce; Pan, Jiawei; Replumaz, Anne; Leloup, Philippe Hervé; Métois, Marianne; Li, Haibing

2018-03-01

The left-lateral strike-slip Xianshuihe fault system located in the eastern Tibetan Plateau is considered as one of the most tectonically active intra-continental fault system in China, along which more than 20 M > 6.5 and more than 10 M > 7 earthquakes occurred since 1700. Therefore, studying its activity, especially its slip rate at different time scales, is essential to evaluate the regional earthquake hazard. Here, we focus on the central segment of the Xianshuihe fault system, where the Xianshuihe fault near Kangding city splays into three branches: the Selaha, Yalahe and Zheduotang faults. In this paper we use precise dating together with precise field measurements of offsets to re-estimate the slip rate of the fault that was suggested without precise age constraints. We studied three sites where the active Selaha fault cuts and left-laterally offsets moraine crests and levees. We measured horizontal offsets of 96 ± 20 m at Tagong levees (TG), 240 ± 15 m at Selaha moraine (SLH) and 80 ± 5 m at Yangjiagou moraine (YJG). Using 10Be cosmogenic dating, we determined abandonment ages at Tagong, Selaha and Yangjiagou of 12.5 (+ 2.5 / - 2.2) ka, 22 ± 2 ka, and 18 ± 2 ka, respectively. By matching the emplacement age of the moraines or levees with their offsets, we obtain late Quaternary horizontal average slip-rates of 7.6 (+ 2.3 / - 1.9) mm/yr at TG and 10.7 (+ 1.3 / - 1.1) mm/yr at SLH, i.e., 5.7-12 mm/yr or between 9.6 and 9.9 mm/yr assuming that the slip rate should be constant between the nearby TG and SLH sites. At YJG, we obtain a lower slip rate of 4.4 ± 0.5 mm/yr, most likely because the parallel Zheduotang fault shares the slip rate at this longitude, therefore suggesting a ∼5 mm/yr slip rate along the Zheduotang fault. The ∼10 mm/yr late Quaternary rate along the Xianshuihe fault is higher than that along the Ganzi fault to the NW (6-8 mm/yr). This appears to be linked to the existence of the Longriba fault system that separates the Longmenshan and Bayan Har blocks north of the Xianshuihe fault system. A higher slip rate along the short (∼60 km) and discontinuous Selaha fault compared to that along the long (∼300 km) and linear Ganzi fault suggests a high hazard for a M > 6 earthquake in the Kangding area in the near future, which could devastate that densely populated city.

Deformation rates across the San Andreas Fault system, central California determined by geology and geodesy

NASA Astrophysics Data System (ADS)

Titus, Sarah J.

The San Andreas fault system is a transpressional plate boundary characterized by sub-parallel dextral strike-slip faults separating internally deformed crustal blocks in central California. Both geodetic and geologic tools were used to understand the short- and long-term partitioning of deformation in both the crust and the lithospheric mantle across the plate boundary system. GPS data indicate that the short-term discrete deformation rate is ˜28 mm/yr for the central creeping segment of the San Andreas fault and increases to 33 mm/yr at +/-35 km from the fault. This gradient in deformation rates is interpreted to reflect elastic locking of the creeping segment at depth, distributed off-fault deformation, or some combination of these two mechanisms. These short-term fault-parallel deformation rates are slower than the expected geologic slip rate and the relative plate motion rate. Structural analysis of folds and transpressional kinematic modeling were used to quantify long-term distributed deformation adjacent to the Rinconada fault. Folding accommodates approximately 5 km of wrench deformation, which translates to a deformation rate of ˜1 mm/yr since the start of the Pliocene. Integration with discrete offset on the Rinconada fault indicates that this portion of the San Andreas fault system is approximately 80% strike-slip partitioned. This kinematic fold model can be applied to the entire San Andreas fault system and may explain some of the across-fault gradient in deformation rates recorded by the geodetic data. Petrologic examination of mantle xenoliths from the Coyote Lake basalt near the Calaveras fault was used to link crustal plate boundary deformation at the surface with models for the accommodation of deformation in the lithospheric mantle. Seismic anisotropy calculations based on xenolith petrofabrics suggest that an anisotropic mantle layer thickness of 35-85 km is required to explain the observed shear wave splitting delay times in central California. The available data are most consistent with models for a broad zone of distributed deformation in the lithospheric mantle.

Denali fault slip rates and Holocene-late Pleistocene kinematics of central Alaska

USGS Publications Warehouse

Matmon, A.; Schwartz, D.P.; Haeussler, Peter J.; Finkel, R.; Lienkaemper, J.J.; Stenner, Heidi D.; Dawson, T.E.

2006-01-01

The Denali fault is the principal intracontinental strike-slip fault accommodating deformation of interior Alaska associated with the Yakutat plate convergence. We obtained the first quantitative late Pleistocene-Holocene slip rates on the Denali fault system from dating offset geomorphic features. Analysis of cosmogenic 10Be concentrations in boulders (n = 27) and sediment (n = 13) collected at seven sites, offset 25-170 m by the Denali and Totschunda faults, gives average ages that range from 2.4 ± 0.3 ka to 17.0 ± 1.8 ka. These offsets and ages yield late Pleistocene-Holocene average slip rates of 9.4 ± 1.6, 12.1 ± 1.7, and 8.4 ± 2.2 mm/yr-1 along the western, central, and eastern Denali fault, respectively, and 6.0 ± 1.2 mm/yr-1 along the Totschunda fault. Our results suggest a westward decrease in the mean Pleistocene-Holocene slip rate. This westward decrease likely results from partitioning of slip from the Denali fault system to thrust faults to the north and west. 2006 Geological Society of America.

Parabolic distribution of circumeastern Snake River Plain seismicity and latest Quaternary faulting: Migratory pattern and association with the Yellowstone hotspot

NASA Astrophysics Data System (ADS)

Anders, Mark H.; Geissman, John Wm.; Piety, Lucille A.; Sullivan, J. Timothy

1989-02-01

The Intermountain and Idaho seismic belts within Idaho, Wyoming, and Montana form an unusual parabolic pattern about the axis of the aseismic eastern Snake River Plain (SRP). This pattern is also reflected in the distribution of latest Quaternary normal faults. Several late Cenozoic normal faults that trend perpendicular to the axis of the eastern SRP extend from the aseismic region to the region of latest Quaternary faulting and seismicity. A study of the late Miocene to Holocene displacement history of one of these, the Grand Valley fault system in southeastern Idaho and western Wyoming, indicates that a locus of high displacement rates has migrated away from the eastern SRP to its present location in southern Star Valley in western Wyoming. In Swan Valley the studied area closest to the eastern SRP, isotopic ages, and paleomagnetic data for over 300 samples from 47 sites on well-exposed late Cenozoic volcanic rocks (the tuff of Spring Creek, the tuff of Heise, the Huckleberry Ridge tuff, the Pine Creek Basalt, and an older tuff thought to be the tuff of Cosgrove Road) are used to demonstrate differences in the displacement rate on the Grand Valley fault over the last ˜10 m.y. Tectonic tilts for these volcanic rocks are estimated by comparing the results of paleomagnetic analyses in Swan Valley to similar analyses of samples from undeformed volcanic rocks outside of Swan Valley. Basin geometry and tilt axes are established using seismic reflection profiles and field mapping. Combining these data with the tilt data makes it possible to calculate displacement rates during discrete temporal intervals. An average displacement rate of ˜1.8 mm/yr is calculated for the Grand Valley fault in Swan Valley between 4.4 and 2.0 Ma. In the subsequent 2.0-m.y. interval the rate dropped 2 orders of magnitude to ˜0.014 mm/yr; during the preceding 5.5-m.y. interval the displacement rate is ˜0.15 mm/yr, or about 1 order of magnitude less than the rate between 4.4 and 2.0 Ma. Mapping of fault scarps and unfaulted deposits along the Grand Valley fault system shows that latest Quaternary fault scarps are restricted to the portion farthest from the eastern SRP, the southern part of the Star Valley fault. Surface displacements estimated from scarp profiles and deposit ages estimated from soil development suggest a latest Quaternary displacement rate of 0.6-1.2 mm/yr for the southern portion of the Star Valley fault. Morphologic evidence suggests that this displacement rate persisted on the Star Valley fault throughout most of the Quaternary. The latest Quaternary displacement rate calculated for the southern portion of the Star Valley fault is similar to the rate calculated for Swan Valley during the interval from 2.0 to 4.4 Ma. This similarity, together with evidence for a low Quaternary displacement rate on the fault system in Swan Valley, suggests that the location of the highest displacement rate has migrated away from the eastern SRP. Other normal faults in southeastern Idaho, northwestern Wyoming, and southwestern Montana, while less well described than the Grand Valley fault system, exhibit a similar outward migrating pattern of increased fault activity followed by quiescence. Furthermore, a temporal and spatial relationship between fault activity and the 3.5 cm/yr northeastward track of the Yellowstone hotspot is observable on the Grand Valley fault system and on other north-northwest trending late Cenozoic faults that border the eastern SRP. The temporal and spatial relationship of Miocene to present high displacement rates for other circumeastern SRP faults and the observable outwardly migrating pattern of fault activity suggest that a similar parabolic distribution of seismicity and high displacement rates was symmetrically positioned about the former position of the hotspot. Moreover, the tandem migration of the hotspot and the parabolic distribution of increased fault activity and seismicity are closely followed by a parabolic-shaped "collapse shadow," or region of fault inactivity and aseismicity. We suggest that the outwardly migrating pattern of increased fault activity (active region) results from reduced integrated lithospheric strength caused by thermal effects of the hotspot. Conversely, the outwardly propagating quiescent region is the result of a reduction or "collapse" of crustal extension rates caused by increased integrated lithospheric strength. Lithospheric strength in this region is increased by addition of mafic materials at the base of the crust and at midcrustal levels. Although the strength of the mantle portion of the lithosphere is reduced, the increased strength of the crust results in a total integrated increase in lithospheric strength. Paradoxically, the surface heat flow data suggest that the region within the interior parabola has a higher heat flow (after accounting for the cooling effects of the eastern SRP aquifer) than the adjacent regions, yet the interior region exhibits significantly lower extension rates. It appears that in this region the surface heat flow is not a good predictor of rates of lithospheric extension.

Strength and Power Correlates of Throwing Velocity on Subelite Male Cricket Players.

PubMed

Freeston, Jonathan L; Carter, Thomas; Whitaker, Gary; Nicholls, Owen; Rooney, Kieron B

2016-06-01

Throwing velocity is an important aspect of fielding in cricket to affect run-outs and reduce the opponent's run-scoring opportunities. Although a relationship between strength and/or power and throwing velocity has been well established in baseball, water polo, and European handball, it has not been adequately explored in cricket. Consequently, this study aimed to determine the relationship between measures of strength and/or power and throwing velocity in cricket players. Seventeen male cricket players (mean ± SD; age, 21.1 ± 1.6 years; height, 1.79 ± 0.06 m; weight, 79.8 ± 6.4 kg) from an elite athlete program were tested for maximal throwing velocity from the stretch position and after a 3-meter shuffle. They were also assessed for strength and power using a range of different measures. Throwing velocity from the stretch position (30.5 ± 2.4 m·s) was significantly related to dominant leg lateral-to-medial jump (LMJ) distance (r = 0.71; p < 0.01), dominant shoulder internal rotation (IR) strength (r = 0.55; p ≤ 0.05), and dominant (r = 0.73; p < 0.01) and nondominant (r = 0.54; p ≤ 0.05) medicine ball rotation (MB Rot) throw velocity and medicine ball chest pass (MB CP) distance (r = 0.67; p < 0.01). A nonsignificant trend was observed for vertical jump (VJ) height (p = 0.06), whereas no significant relationships were observed for nondominant LMJ distance (p = 0.97), nondominant shoulder IR strength (p = 0.80), 1 repetition maximum (RM) squat strength (p = 0.57), 1RM bench press strength (p = 0.90), height (p = 0.33), or weight (p = 0.29). Multiple regression analysis revealed that dominant MB Rot and MB CP explained 66% of the variance. The results were similar for velocity after a shuffle step (31.8 ± 2.1 m·s); however, VJ height reached statistical significance (r = 0.51; p ≤ 0.05). The multiple regression was also similar with MB Rot and MB CP explaining 70% of the variance. The cricketers in this study threw with greater velocity than elite junior and subelite senior cricketers but with lower velocities than elite senior cricketers and collegiate level and professional baseball players. This is the first study to demonstrate a link between strength and/or power and throwing velocity in cricket players and highlight the importance of power development as it relates to throwing velocity. Exercises that more closely simulated the speed (body weight jumps and medicine ball throws) or movement pattern (shoulder IR) of overhead throwing were greater predictors of throwing velocity. Strength and conditioning staff should assess and develop power to enhance throwing performance in cricket players. Exercises with greater movement and speed specificity to throwing should be used in preference over exercises that are slower and have less movement specificity to the throwing motion. Cricket players should engage in power training to bridge the gap in performance between them and baseball players.

Medial elbow injury in young throwing athletes

PubMed Central

Gregory, Bonnie; Nyland, John

2013-01-01

Summary This report reviews the anatomy, overhead throwing biomechanics, injury mechanism and incidence, physical examination and diagnosis, diagnostic imaging and conservative treatment of medial elbow injuries in young throwing athletes. Based on the information a clinical management decision-making algorithm is presented. PMID:23888291

A fault-based model for crustal deformation, fault slip-rates and off-fault strain rate in California

USGS Publications Warehouse

Zeng, Yuehua; Shen, Zheng-Kang

2016-01-01

We invert Global Positioning System (GPS) velocity data to estimate fault slip rates in California using a fault‐based crustal deformation model with geologic constraints. The model assumes buried elastic dislocations across the region using Uniform California Earthquake Rupture Forecast Version 3 (UCERF3) fault geometries. New GPS velocity and geologic slip‐rate data were compiled by the UCERF3 deformation working group. The result of least‐squares inversion shows that the San Andreas fault slips at 19–22  mm/yr along Santa Cruz to the North Coast, 25–28  mm/yr along the central California creeping segment to the Carrizo Plain, 20–22  mm/yr along the Mojave, and 20–24  mm/yr along the Coachella to the Imperial Valley. Modeled slip rates are 7–16  mm/yr lower than the preferred geologic rates from the central California creeping section to the San Bernardino North section. For the Bartlett Springs section, fault slip rates of 7–9  mm/yr fall within the geologic bounds but are twice the preferred geologic rates. For the central and eastern Garlock, inverted slip rates of 7.5 and 4.9  mm/yr, respectively, match closely with the geologic rates. For the western Garlock, however, our result suggests a low slip rate of 1.7  mm/yr. Along the eastern California shear zone and southern Walker Lane, our model shows a cumulative slip rate of 6.2–6.9  mm/yr across its east–west transects, which is ∼1  mm/yr increase of the geologic estimates. For the off‐coast faults of central California, from Hosgri to San Gregorio, fault slips are modeled at 1–5  mm/yr, similar to the lower geologic bounds. For the off‐fault deformation, the total moment rate amounts to 0.88×1019  N·m/yr, with fast straining regions found around the Mendocino triple junction, Transverse Ranges and Garlock fault zones, Landers and Brawley seismic zones, and farther south. The overall California moment rate is 2.76×1019  N·m/yr, which is a 16% increase compared with the UCERF2 model.

Acute Effect of Countermovement Jumping on Throwing Performance in Track and Field Athletes During Competition.

PubMed

Karampatsos, Giorgos P; Korfiatis, Panagiotis G; Zaras, Nikolaos D; Georgiadis, Giorgos V; Terzis, Gerasimos D

2017-02-01

Karampatsos, GP, Korfiatis, PG, Zaras, ND, Georgiadis, GV, and Terzis, GD. Acute effect of countermovement jumping on throwing performance in track and field athletes during competition. J Strength Cond Res 32(1): 359-364, 2017-The purpose of the study was to investigate whether performing 3 consecutive countermovement jumps (CMJs) just before an attempt enhances performance in track and field throwers during competition. Twelve shot putters, 8 hammer throwers, 9 discus throwers, and 3 javelin throwers of both sexes participated in the study. They performed 3 maximal CMJs 85 ± 12 seconds before the second, fourth, and sixth attempt during 3 different official competitions of national level. Maximal strength (1 repetition maximum [1RM]) in squat and bench press was measured 1 week after the competition. Mean throwing performance was significantly higher after the CMJs intervention (2.66 ± 4.3%, range of increase 0.02-18.98%, p = 0.0001). Similarly, maximum throwing performance was significantly higher after the CMJs (2.76 ± 3.29%, range of increase 0.09-13.93%, p = 0.0009). All but 2 athletes increased their best performance after the CMJs. The percentage increase in performance was similar between sexes (male athletes 2.56 ± 3.01%; female athletes 3.06 ± 3.76%, p = 0.677), but it was higher for the "lighter throws" (discus and javelin throw: 4.66 ± 4.11%) compared with the "heavier throws" (shot and hammer throw: 1.62 ± 2.04%, p = 0.008). The percentage increase in performance was not significantly correlated with 1RM squat or bench press, anthropometric characteristics, and personal best performance. These results suggest that performing 3 CMJs approximately 1 minute before an attempt may increase track and field throwing performance during competition.

Comparing the tensile strength of square and reversing half-hitch alternating post knots

PubMed Central

Wu, Vincent; Sykes, Edward A.; Mercer, Dale; Hopman, Wilma M.; Tang, Ephraim

2017-01-01

Background Square knots are the gold standard in hand-tie wound closure, but are difficult to reproduce in deep cavities, inadvertently resulting in slipknots. The reversing half-hitch alternating post (RHAP) knot has been suggested as an alternative owing to its nonslip nature and reproducibility in limited spaces. We explored whether the RHAP knot is noninferior to the square knot by assessing tensile strength. Methods We conducted 10 trials for each baseline and knot configuration, using 3–0 silk and 3–0 polyglactin 910 sutures. We compared tensile strength between knot configurations at the point of knot failure between slippage and breakage. Results Maximal failure strength (mean ± SD) in square knots was reached with 4-throw in both silk (30 ± 1.5 N) and polyglactin 910 (39 ± 12 N). For RHAP knots, maximal failure strength was reached at 5-throw for both silk (31 ± 1.5 N) and polyglactin 910 (41 ± 13 N). In both sutures, there were no strength differences between 3-throw square and 4-throw RHAP, between 4-throw square and 5-throw RHAP, or between 5-throw square and 6-throw RHAP knots. Polyglactin 910 sutures, in all knot configurations, were more prone to slippage than silk sutures (p < 0.001). Conclusion The difference in mean tensile strength could be attributed to the proportion of knot slippage versus breakage, which is material-dependent. Future studies can re-evaluate findings in monofilament sutures and objectively assess the reproducibility of square and RHAP knots in deep cavities. Our results indicate that RHAP knots composed of 1 extra throw provide equivalent strength to square knots and may be an alternative when performing hand-ties in limited cavities with either silk or polyglactin 910 sutures. PMID:28327276

Comparing the tensile strength of square and reversing half-hitch alternating post knots.

PubMed

Wu, Vincent; Sykes, Edward A; Mercer, Dale; Hopman, Wilma M; Tang, Ephraim

2017-06-01

Square knots are the gold standard in hand-tie wound closure, but are difficult to reproduce in deep cavities, inadvertently resulting in slipknots. The reversing half-hitch alternating post (RHAP) knot has been suggested as an alternative owing to its nonslip nature and reproducibility in limited spaces. We explored whether the RHAP knot is noninferior to the square knot by assessing tensile strength. We conducted 10 trials for each baseline and knot configuration, using 3-0 silk and 3-0 polyglactin 910 sutures. We compared tensile strength between knot configurations at the point of knot failure between slippage and breakage. Maximal failure strength (mean ± SD) in square knots was reached with 4-throw in both silk (30 ± 1.5 N) and polyglactin 910 (39 ± 12 N). For RHAP knots, maximal failure strength was reached at 5-throw for both silk (31 ± 1.5 N) and polyglactin 910 (41 ± 13 N). In both sutures, there were no strength differences between 3-throw square and 4-throw RHAP, between 4-throw square and 5-throw RHAP, or between 5-throw square and 6-throw RHAP knots. Polyglactin 910 sutures, in all knot configurations, were more prone to slippage than silk sutures ( p < 0.001). The difference in mean tensile strength could be attributed to the proportion of knot slippage versus breakage, which is material-dependent. Future studies can re-evaluate findings in monofilament sutures and objectively assess the reproducibility of square and RHAP knots in deep cavities. Our results indicate that RHAP knots composed of 1 extra throw provide equivalent strength to square knots and may be an alternative when performing hand-ties in limited cavities with either silk or polyglactin 910 sutures.

Effect of different training programs on the velocity of overarm throwing: a brief review.

PubMed

van den Tillaar, Roland

2004-05-01

Throwing velocity in overarm throwing is of major importance in sports like baseball, team handball, javelin, and water polo. The purpose of this literature review was to give an overview of the effect of different training programs on the throwing velocity in overarm throwing, provide a theoretical framework that explains findings, and give some practical applications based on these findings. The training studies were divided into 4 categories: (a) specific resistance training with an overload of velocity, (b) specific resistance training with an overload of force, (c) specific resistance training with a combination of overload of force and velocity, and (d) general resistance training according to the overload of force. Each category is presented and discussed.

Assessment of Late Quaternary strain partitioning in the Afar Triple Junction: Dobe and Hanle grabens, Ethiopia and Djibouti

NASA Astrophysics Data System (ADS)

Polun, S. G.; Stockman, M. B.; Hickcox, K.; Horrell, D.; Tesfaye, S.; Gomez, F. G.

2015-12-01

As the only subaerial exposure of a ridge - ridge - ridge triple junction, the Afar region of Ethiopia and Djibouti offers a rare opportunity to assess strain partitioning within this type of triple junction. Here, the plate boundaries do not link discretely, but rather the East African rift meets the Red Sea and Gulf of Aden rifts in a zone of diffuse normal faulting characterized by a lack of magmatic activity, referred to as the central Afar. An initial assessment of Late Quaternary strain partitioning is based on faulted landforms in the Dobe - Hanle graben system in Ethiopia and Djibouti. These two extensional basins are connected by an imbricated accommodation zone. Several fault scarps occur within terraces formed during the last highstand of Lake Dobe, around 5 ka - they provide a means of calibrating a numerical model of fault scarp degradation. Additional timing constraints will be provided by pending exposure ages. The spreading rates of both grabens are equivalent, however in Dobe graben, extension is partitioned 2:1 between northern, south dipping faults and the southern, north dipping fault. Extension in Hanle graben is primarily focused on the north dipping Hanle fault. On the north margin of Dobe graben, the boundary fault bifurcates, where the basin-bordering fault displays a significantly higher modeled uplift rate than the more distal fault, suggesting a basinward propagation of faulting. On the southern Dobe fault, surveyed fault scarps have ages ranging from 30 - 5 ka with uplift rates of 0.71, 0.47, and 0.68 mm/yr, suggesting no secular variation in slip rates from the late Plestocene through the Holocene. These rates are converted into horizontal stretching estimates, which are compared with regional strain estimated from velocities of relatively sparse GPS data.

Late quaternary slip-rate variations along the Warm Springs Valley fault system, northern Walker Lane, California-Nevada border

USGS Publications Warehouse

Gold, Ryan; dePolo, Craig; Briggs, Richard W.; Crone, Anthony

2013-01-01

The extent to which faults exhibit temporally varying slip rates has important consequences for models of fault mechanics and probabilistic seismic hazard. Here, we explore the temporal behavior of the dextral‐slip Warm Springs Valley fault system, which is part of a network of closely spaced (10–20 km) faults in the northern Walker Lane (California–Nevada border). We develop a late Quaternary slip record for the fault using Quaternary mapping and high‐resolution topographic data from airborne Light Distance and Ranging (LiDAR). The faulted Fort Sage alluvial fan (40.06° N, 119.99° W) is dextrally displaced 98+42/-43 m, and we estimate the age of the alluvial fan to be 41.4+10.0/-4.8 to 55.7±9.2  ka, based on a terrestrial cosmogenic 10Be depth profile and 36Cl analyses on basalt boulders, respectively. The displacement and age constraints for the fan yield a slip rate of 1.8 +0.8/-0.8 mm/yr to 2.4 +1.2/-1.1 mm/yr (2σ) along the northern Warm Springs Valley fault system for the past 41.4–55.7 ka. In contrast to this longer‐term slip rate, shorelines associated with the Sehoo highstand of Lake Lahontan (~15.8  ka) adjacent to the Fort Sage fan are dextrally faulted at most 3 m, which limits a maximum post‐15.8 ka slip rate to 0.2  mm/yr. These relations indicate that the post‐Lahontan slip rate on the fault is only about one‐tenth the longer‐term (41–56 ka) average slip rate. This apparent slip‐rate variation may be related to co‐dependent interaction with the nearby Honey Lake fault system, which shows evidence of an accelerated period of mid‐Holocene earthquakes.

46 CFR 199.170 - Line-throwing appliance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Line-throwing appliance. 199.170 Section 199.170 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LIFESAVING APPLIANCES AND ARRANGEMENTS... appliance. (a) General. Each vessel must have a line-throwing appliance approved under approval series 160...

Active faulting induced by the slip partitioning in the Lesser Antilles arc

NASA Astrophysics Data System (ADS)

Leclerc, Frédérique; Feuillet, Nathalie

2010-05-01

AGUADOMAR marine cruise data acquired 11 years ago allowed us to identified and map two main sets of active faults within the Lesser Antilles arc (Feuillet et al., 2002; 2004). The faults belonging to the first set, such as Morne-Piton in Guadeloupe, bound up to 100km-long and 50km-wide arc-perpendicular graben or half graben that disrupt the fore-arc reef platforms. The faults of the second set form right-stepping en echelon arrays, accommodating left-lateral slip along the inner, volcanic islands. The two fault systems form a sinistral horsetail east of the tip of the left-lateral Puerto Rico fault zone that takes up the trench-parallel component of convergence between the North-American and Caribbean plates west of the Anegada passage. In other words, they together accommodate large-scale slip partitioning along the northeastern arc, consistent with recent GPS measurements (Lopez et al., 2006). These intraplate faults are responsible for a part of the shallow seismicity in the arc and have produce damaging historical earthquakes. Two magnitude 6.3 events occurred in the last 25 years along the inner en echelon faults, the last one on November 21 2004 in Les Saintes in the Guadeloupe archipelago. To better constrain the seismic hazard related to the inner arc faults and image the ruptures and effects on the seafloor of Les Saintes 2004 earthquake, we acquired new marine data between 23 February and 25 March 2009 aboard the French R/V le Suroît during the GWADASEIS cruise. We present here the data (high-resolution 72 channel and very high-resolution chirp 3.5 khz seismic reflection profiles, EM300 multibeam bathymetry, Küllenberg coring and SAR imagery) and the first results. We identified, mapped and characterized in detail several normal to oblique fault systems between Martinique and Saba. They offset the seafloor by several hundred meters and crosscut all active volcanoes, among them Nevis Peak, Soufriere Hills, Soufriere de Guadeloupe and Montagne Pelée. Some faults, located between Guadeloupe and Montserrat have throws up to thousand meters. Between St Lucia and Martinique, the St Lucia channel is crosscut by several normal faults with scarps up to 100m-high. These faults extend onshore and cut the southern shore of Martinique. Given their length (~20km), they could produce magnitude 6 or more earthquakes in the most tourist towns of the island (St Anne, St Lucie). Recent coseismic offsets could be identified along most faults in the chirp profiles. Turbidite deposits recognized in the Küllenberg cores could be related to damaging earthquakes. High resolution SAR imagery (25 cm) reveals several coseismic scarps in Les Saintes channel along the faults that ruptured in 2004. References: Feuillet, N., I. Manighetti, and P. Tapponnier, Arc parallel extension and localization of volcanic complexes in guadeloupe, lesser antilles, Journal of Geophysical Research, 107, 2002. Feuillet, N., P. Tapponnier, I. Manighetti, B. Villemant, and G. C. P. King, Differential uplift and tilt of pleistocene reef platforms and quaternary slip Lopez, A.M., S. Stein, T. Dixon, G. Sella, E. Calais, P. Jansma, J. Weber, and P. La Femina, Is there a northern lesser antilles forearc block ?, Geophysical Research Letters, 33, 2006.

Relationship between sitting volleyball performance and field fitness of sitting volleyball players in Korea

PubMed Central

Jeoung, Bogja

2017-01-01

The purpose of this study was to evaluate the relationship between sitting volleyball performance and the field fitness of sitting volleyball players. Forty-five elite sitting volleyball players participated in 10 field fitness tests. Additionally, the players’ head coach and coach assessed their volleyball performance (receive and defense, block, attack, and serve). Data were analyzed with SPSS software version 21 by using correlation and regression analyses, and the significance level was set at P< 0.05. The results showed that chest pass, overhand throw, one-hand throw, one-hand side throw, splint, speed endurance, reaction time, and graded exercise test results had a statistically significant influence on the players’ abilities to attack, serve, and block. Grip strength, t-test, speed, and agility showed a statistically significant relationship with the players’ skill at defense and receive. Our results showed that chest pass, overhand throw, one-hand throw, one-hand side throw, speed endurance, reaction time, and graded exercise test results had a statistically significant influence on volleyball performance. PMID:29326896

Clinical measurement of the dart throwing motion of the wrist: variability, accuracy and correction.

PubMed

Vardakastani, Vasiliki; Bell, Hannah; Mee, Sarah; Brigstocke, Gavin; Kedgley, Angela E

2018-01-01

Despite being functionally important, the dart throwing motion is difficult to assess accurately through goniometry. The objectives of this study were to describe a method for reliably quantifying the dart throwing motion using goniometric measurements within a healthy population. Wrist kinematics of 24 healthy participants were assessed using goniometry and optical motion tracking. Three wrist angles were measured at the starting and ending points of the motion: flexion-extension, radial-ulnar deviation and dart throwing motion angle. The orientation of the dart throwing motion plane relative to the flexion-extension axis ranged between 28° and 57° among the tested population. Plane orientations derived from optical motion capture differed from those calculated through goniometry by 25°. An equation to correct the estimation of the plane from goniometry measurements was derived. This was applied and differences in the orientation of the plane were reduced to non-significant levels, enabling the dart throwing motion to be measured using goniometry alone.

Comparison of the backward overhead medicine ball throw to power production in college football players.

PubMed

Mayhew, Jerry L; Bird, Michael; Cole, Mary L; Koch, Alex J; Jacques, Jeff A; Ware, John S; Buford, Brittney N; Fletcher, Kate M

2005-08-01

The purpose of this study was to determine the relationship of the backward overhead medicine ball (BOMB) throw to power production in college football players. Forty National Collegiate Athletic Association Division II college football players were studied at the end of an 8-week off-season conditioning program for power output determined from a countermovement vertical jump on a force plate and for maximal distance in the standing BOMB throw. Although the reliability of the BOMB test was high (interclass correlation coefficient = 0.86), there was a significant learning effect across 3 trials (p < 0.01). Peak and average powers generated during the vertical jump correlated moderately but significantly with the best BOMB throw distance (r = 0.59 and 0.63, respectively). Considering power relative to body mass or lean body mass failed to produce significant correlations with BOMB throw distance (r = 0.27 and 0.28, respectively). Therefore, the BOMB throw may have limited potential as a predictor of total body explosive power in college football players.

A New Geological Slip Rate Estimate for the Calico Fault, Eastern California: Implications for Geodetic Versus Geologic Rate Estimates in the Eastern California Shear Zone

NASA Astrophysics Data System (ADS)

Wetmore, P. H.; Xie, S.; Gallant, E.; Owen, L. A.; Dixon, T. H.

2017-12-01

Fault slip rate is fundamental to accurate seismic hazard assessment. In the Mojave Desert section of the Eastern California Shear Zone previous studies have suggested a discrepancy between short-term geodetic and long-term geologic slip rate estimates. Understanding the origin of this discrepancy could lead to better understanding of stress evolution, and improve earthquake hazard estimates in general. We measured offsets in alluvial fans along the Calico fault near Newberry Springs, California, and used exposure age dating based on the cosmogenic nuclide 10Be to date the offset landforms. We derive a mean slip rate of 3.6 mm/yr, representing an average over the last few hundred thousand years, significantly faster than previous estimates. Considering numerous faults in the Mojave Desert and limited geologic slip rate estimates, it is premature to claim a geologic versus geodetic "discrepancy" for the ECSZ. More slip rate data, from all faults with the ECSZ, are needed to provide a statistically meaningful assessment of the geologic rates for each of the faults comprising the ECSZ.

Holocene slip rate along the northern Kongur Shan extensional system: insights on the large pull-apart structure in the NE Pamir

NASA Astrophysics Data System (ADS)

Pan, J.; Li, H.; Chevalier, M.; Liu, D.; Sun, Z.; Pei, J.; Wu, F.; Xu, W.

2013-12-01

Located at the northwestern end of the Himalayan-Tibetan orogenic belt, the Kongur Shan extensional system (KES) is a significant tectonic unit in the Chinese Pamir. E-W extension of the KES accommodates deformation due to the India/Asia collision in this area. Cenozoic evolution of the KES has been extensively studied, whereas Late Quaternary deformation along the KES is still poorly constrained. Besides, whether the KES is the northern extension of the Karakorum fault is still debated. Well-preserved normal fault scarps are present all along the KES. Interpretation of satellite images as well as field investigation allowed us to map active normal faults and associated vertically offset geomorphological features along the KES. At one site along the northern Kongur Shan detachment fault, in the eastern Muji basin, a Holocene alluvial fan is vertically offset by the active fault. We measured the vertical displacement of the fan with total station, and collected quartz cobbles for cosmogenic nuclide 10Be dating. Combining the 5-7 m offset and the preliminary surface-exposure ages of ~2.7 ka, we obtain a Holocene vertical slip-rate of 1.8-2.6 mm/yr along the fault. This vertical slip-rate is comparable to the right-lateral horizontal-slip rate along the Muji fault (~4.5 mm/yr, which is the northern end of the KES. Our result is also similar to the Late Quaternary slip-rate derived along the KES around the Muztagh Ata as well as the Tashkurgan normal fault (1-3 mm/yr). Geometry, kinematics, and geomorphology of the KES combined with the compatible slip-rate between the right-lateral strike-slip Muji fault and the Kongur Shan normal fault indicate that the KES may be an elongated pull-apart basin formed between the EW-striking right-lateral strike-slip Muji fault and the NW-SE-striking Karakorum fault. This unique elongated pull-apart structure with long normal fault in the NS direction and relatively short strike-slip fault in the ~EW direction seems to still be in formation, with the Karakorum fault still propagating to the north.

Synthetic velocity gradient map of the San Francisco Bay region, California, supports use of average block velocities to estimate fault slip rate where effective locking depth is small relative to inter-fault distance

NASA Astrophysics Data System (ADS)

Graymer, R. W.; Simpson, R. W.

2014-12-01

Graymer and Simpson (2013, AGU Fall Meeting) showed that in a simple 2D multi-fault system (vertical, parallel, strike-slip faults bounding blocks without strong material property contrasts) slip rate on block-bounding faults can be reasonably estimated by the difference between the mean velocity of adjacent blocks if the ratio of the effective locking depth to the distance between the faults is 1/3 or less ("effective" locking depth is a synthetic parameter taking into account actual locking depth, fault creep, and material properties of the fault zone). To check the validity of that observation for a more complex 3D fault system and a realistic distribution of observation stations, we developed a synthetic suite of GPS velocities from a dislocation model, with station location and fault parameters based on the San Francisco Bay region. Initial results show that if the effective locking depth is set at the base of the seismogenic zone (about 12-15 km), about 1/2 the interfault distance, the resulting synthetic velocity observations, when clustered, do a poor job of returning the input fault slip rates. However, if the apparent locking depth is set at 1/2 the distance to the base of the seismogenic zone, or about 1/4 the interfault distance, the synthetic velocity field does a good job of returning the input slip rates except where the fault is in a strong restraining orientation relative to block motion or where block velocity is not well defined (for example west of the northern San Andreas Fault where there are no observations to the west in the ocean). The question remains as to where in the real world a low effective locking depth could usefully model fault behavior. Further tests are planned to define the conditions where average cluster-defined block velocities can be used to reliably estimate slip rates on block-bounding faults. These rates are an important ingredient in earthquake hazard estimation, and another tool to provide them should be useful.

Stability of fault submitted to fluid injections

NASA Astrophysics Data System (ADS)

Brantut, N.; Passelegue, F. X.; Mitchell, T. M.

2017-12-01

Elevated pore pressure can lead to slip reactivation on pre-existing fractures and faults when the coulomb failure point is reached. From a static point of view, the reactivation of fault submitted to a background stress (τ0) is a function of the peak strength of the fault, i.e. the quasi-static effective friction coefficient (µeff). However, this theory is valid only when the entire fault is affected by fluid pressure, which is not the case in nature, and during human induced-seismicity. In this study, we present new results about the influence of the injection rate on the stability of faults. Experiments were conducted on a saw-cut sample of westerly granite. The experimental fault was 8 cm length. Injections were conducted through a 2 mm diameter hole reaching the fault surface. Experiments were conducted at four different order magnitudes fluid pressure injection rates (from 1 MPa/minute to 1 GPa/minute), in a fault system submitted to 50 and 100 MPa confining pressure. Our results show that the peak fluid pressure leading to slip depends on injection rate. The faster the injection rate, the larger the peak fluid pressure leading to instability. Wave velocity surveys across the fault highlighted that decreasing the injection-rate leads to an increase of size of the fluid pressure perturbation. Our result demonstrate that the stability of the fault is not only a function of the fluid pressure requires to reach the failure criterion, but is mainly a function of the ratio between the length of the fault affected by fluid pressure and the total fault length. In addition, we show that the slip rate increases with the background effective stress and with the intensity of the fluid pressure pertubation, i.e. with the excess shear stress acting on the part of the fault pertubated by fluid injection. Our results suggest that crustal fault can be reactivated by local high fluid overpressures. These results could explain the "large" magnitude human-induced earthquakes recently observed in Oklahoma (Mw 5.6, 2016).

Frequent Immediate Knowledge of Results Enhances the Increase of Throwing Velocity in Overarm Handball Performance.

PubMed

Štirn, Igor; Carruthers, Jamie; Šibila, Marko; Pori, Primož

2017-02-01

In the present study, the effect of frequent, immediate, augmented feedback on the increase of throwing velocity was investigated. An increase of throwing velocity of a handball set shot when knowledge of results was provided or not provided during training was compared. Fifty female and seventy-three male physical education students were assigned randomly to the experimental or control group. All participants performed two series of ten set shots with maximal effort twice a week for six weeks. The experimental group received information regarding throwing velocity measured by a radar gun immediately after every shot, whereas the control group did not receive any feedback. Measurements of maximal throwing velocity of an ordinary handball and a heavy ball were performed, before and after the training period and compared. Participants who received feedback on results attained almost a four times greater relative increase of the velocity of the normal ball (size 2) as compared to the same intervention when feedback was not provided (8.1 ± 3.6 vs. 2.7 ± 2.9%). The velocity increases were smaller, but still significant between the groups for throws using the heavy ball (5.1 ± 4.2 and 2.5 ± 5.8 for the experimental and control group, respectively). Apart from the experimental group throwing the normal ball, no differences in velocity change for gender were obtained. The results confirmed that training oriented towards an increase in throwing velocity became significantly more effective when frequent knowledge of results was provided.

Slip-rate measurements on the Karakorum Fault may imply secular variations in fault motion.

PubMed

Chevalier, M-L; Ryerson, F J; Tapponnier, P; Finkel, R C; Van Der Woerd, J; Haibing, Li; Qing, Liu

2005-01-21

Beryllium-10 surface exposure dating of offset moraines on one branch of the Karakorum Fault west of the Gar basin yields a long-term (140- to 20-thousand-year) right-lateral slip rate of approximately 10.7 +/- 0.7 millimeters per year. This rate is 10 times larger than that inferred from recent InSAR analyses ( approximately 1 +/- 3 millimeters per year) that span approximately 8 years and sample all branches of the fault. The difference in slip-rate determinations suggests that large rate fluctuations may exist over centennial or millennial time scales. Such fluctuations would be consistent with mechanical coupling between the seismogenic, brittle-creep, and ductile shear sections of faults that reach deep into the crust.

Feasibility of estimating cementation rates in a brittle fault zone using Sr/Ca partition coefficients for sedimentary diagenesis

NASA Astrophysics Data System (ADS)

Hadizadeh, Jafar; Foit, Franklin F.

2000-04-01

Cement phases such as calcite or quartz often incorporate trace elements from the parent fluids as they crystallize. Experimental sedimentary diagenesis indicates that trace element partition coefficients reflect rates of cementation. The applicability of these findings to fault zone cementation is examined as we make a preliminary attempt to estimate calcite cementation rate in a brittle fault zone directly from the fault-rock composition data. Samples for this study were collected from the Knoxville outcrop of the Saltville fault in Tennessee. The cementation rates for the fault rock samples range from 1×10 -12 to 3×10 -13 m3/ h per m, in agreement with some experimental rates and the rates reported for samples from the DSDP sites. When applied to a non-responsive pore-system model, these rates result in rapid precipitation sealing indicating the influence exerted by the surface-area/volume ratio of the pore network. We find it feasible to obtain a reasonable range of values for the cementation rate using the trace element partition method. However, the study also indicates the need for relatively accurate values for the trace/carrier element ratio in the fault zone syntectonic pore fluid, and exhumed cement.

Geophysical Survey of the 1978 Seismo-volcanic Crisis in the Asal-Ghoubbet Rift (Afar Depression, Djibouti) and the Post-rifting Deformations

NASA Astrophysics Data System (ADS)

Doubre, C.; Ruegg, J.; de Chabalier, J.; Vigny, C.; Jacques, E.

2006-12-01

In November 1978, a seismo-volcanic crisis occurred in the Asal-Ghoubbet Rift, which is located at the western termination of the oceanic Aden Ridge propagating inland into the Afar Depression and accommodates a large part of the divergent motion of the Arabia and Somalia plates. This episode offered the opportunity to study the rifting process controlling the evolution of a sub-aerial opening segment at the transition from continental break-up to oceanic spreading. This major crustal spreading episode started with two major earthquakes in the subaerial part of the rift (mb=5.3 and 5.0) and was followed by the week-long, basaltic fissure eruption of the Ardukoba at the western tip of the central volcanic chain. The geophysical survey carried out for the crisis was possible by means of the Arta Observatory in Djibouti within the framework of field surveys financed by the French agency CNRS-INSU. This allowed the measurements of the surface breaks (dry open fissures up to 100 m, normal fault throws up to 80 cm), the crustal deformation by geodetic networks and leveling (up to 2m of horizontal widening, 70 cm of inner-floor subsidence), and the evolution of the seismic activity (eastward migration along the Aden Ridge) associated with this rifting event. Elastic modeling shows that both the deformation pattern and the seismic activity can be explained by the aseismic intrusion of two dykes below the rift inner-floor. Subsequently, a continuous geodetic and seismic monitoring has been maintained and shows that the post-dyke injection evolution of the rift is dominated by two distinct periods. During the six first years (1979-1986), high rates of horizontal opening and slip of creeping normal faults accommodate the subsidence of the inner-floor surrimposed to the development of a 25 km-wide uplift. Since 1986-87, the strain rates have decreased and currently reach values consistent with long-term velocities deduced from morpho-tectonic studies. The evolution of the deformation field deduced from geodetic and seismic data is discussed in terms of kinematic relation with creeping faults and dyking, continuous aseismic dyking injection/inflation at depth, and transient variations associated with a relaxation mechanism related to the sudden opening of dykes. An active process involving fluid migration is required to explain the discrepancy between the far field and near field velocities measured by GPS, the general doming identified by leveling data, the periods of slip acceleration along continuously creeping faults observed from InSAR data, and the time variations of low-magnitude seismicity. All these observations therefore illustrate that some parts of the crust in the rift during the rifting episode and throughout the whole post-rifting period are in a critical state close to failure.

Spatial and temporal patterns of fault creep across an active salt system, Canyonlands National Park, Utah

NASA Astrophysics Data System (ADS)

Kravitz, K.; Mueller, K. J.; Furuya, M.; Tiampo, K. F.

2017-12-01

First order conditions that control creeping behavior on faults include the strength of faulted materials, fault maturity and stress changes associated with seismic cycles. We present mapping of surface strain from differential interferometric synthetic aperture radar (DInSAR) of actively creeping faults in Eastern Utah that form by reactivation of older joints and faults. A nine-year record of displacement across the region using descending ERS scenes from 1992-2001 suggests maximum slip rates of 1 mm/yr. Time series analysis shows near steady rates across the region consistent with the proposed ultra-weak nature of these faults as suggested by their dilating nature, based on observations of sinkholes, pit chains and recently opened fissures along their lengths. Slip rates along the faults in the main part of the array are systematically faster with closer proximity to the Colorado River Canyon, consistent with mechanical modeling of the boundary conditions that control the overall salt system. Deeply incised side tributaries coincide with and control the edges of the region with higher strain rates. Comparison of D:L scaling at decadal scales in fault bounded grabens (as defined by InSAR) with previous measurements of total slip (D) to length (L) is interpreted to suggest that faults reached nearly their current lengths relatively quickly (i.e. displaying low displacement to length scaling). We argue this may then have been followed by along strike slip distributions where the centers of the grabens slip more rapidly than their endpoints, resulting in a higher D:L ratio over time. InSAR mapping also points to an increase in creep rates in overlap zones where two faults became hard-linked at breached relay ramps. Additionally, we see evidence for soft-linkage, where displacement profiles along a graben coincide with obvious fault segments. While an endmember case (ultra-weak faults sliding above a plastic substrate), structures in this region highlight mechanical behavior driven by rheological conditions that promote steady state slip in a complex array of extensional faults. Besides defining how creep varies along strike on individual faults, our work also hints at how strain rates may vary within the context of ongoing strain and fault linkage in a complex fault array.

A 667 year record of coseismic and interseismic Coulomb stress changes in central Italy reveals the role of fault interaction in controlling irregular earthquake recurrence intervals

NASA Astrophysics Data System (ADS)

Wedmore, L. N. J.; Faure Walker, J. P.; Roberts, G. P.; Sammonds, P. R.; McCaffrey, K. J. W.; Cowie, P. A.

2017-07-01

Current studies of fault interaction lack sufficiently long earthquake records and measurements of fault slip rates over multiple seismic cycles to fully investigate the effects of interseismic loading and coseismic stress changes on the surrounding fault network. We model elastic interactions between 97 faults from 30 earthquakes since 1349 A.D. in central Italy to investigate the relative importance of co-seismic stress changes versus interseismic stress accumulation for earthquake occurrence and fault interaction. This region has an exceptionally long, 667 year record of historical earthquakes and detailed constraints on the locations and slip rates of its active normal faults. Of 21 earthquakes since 1654, 20 events occurred on faults where combined coseismic and interseismic loading stresses were positive even though 20% of all faults are in "stress shadows" at any one time. Furthermore, the Coulomb stress on the faults that experience earthquakes is statistically different from a random sequence of earthquakes in the region. We show how coseismic Coulomb stress changes can alter earthquake interevent times by 103 years, and fault length controls the intensity of this effect. Static Coulomb stress changes cause greater interevent perturbations on shorter faults in areas characterized by lower strain (or slip) rates. The exceptional duration and number of earthquakes we model enable us to demonstrate the importance of combining long earthquake records with detailed knowledge of fault geometries, slip rates, and kinematics to understand the impact of stress changes in complex networks of active faults.

46 CFR 133.170 - Line-throwing appliance.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Line-throwing appliance. 133.170 Section 133.170 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS LIFESAVING SYSTEMS Requirements for All OSVs § 133.170 Line-throwing appliance. (a) General. Each OSV must have a...

46 CFR 133.170 - Line-throwing appliance.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Line-throwing appliance. 133.170 Section 133.170 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS LIFESAVING SYSTEMS Requirements for All OSVs § 133.170 Line-throwing appliance. (a) General. Each OSV must have a...

Seismicity rate surge on faults after shut-in: poroelastic response to fluid injection

NASA Astrophysics Data System (ADS)

Chang, K. W.; Yoon, H.; Martinez, M. J.

2017-12-01

Subsurface energy activities such as geological CO2 storage and wastewater injection require injecting large amounts of fluid into the subsurface, which will alter the states of pore pressure and stress in the storage formation. One of the main issues for injection-induced seismicity is the post shut-in increases in the seismicity rate, often observed in the fluid-injection operation sites. The rate surge can be driven by the following mechanisms: (1) pore-pressure propagation into distant faults after shut-in and (2) poroelastic stressing caused by well operations, depending on fault geometry, hydraulic and mechanical properties of the formation, and injection history. We simulate the aerial view of the target reservoir intersected by strike-slip faults, in which injection-induced pressure buildup encounters the faults directly. We examine the poroelastic response of the faults to fluid injection and perform a series of sensitivity tests considering: (1) permeability of the fault zone, (2) locations and the number of faults with respect to the injection point, and (3) well operations with varying the injection rate. Our analysis of the Coulomb stress change suggests that the sealing fault confines pressure diffusion which stabilizes or weakens the nearby conductive fault depending on the injection location. We perform the sensitivity test by changing injection scenarios (time-dependent rates), while keeping the total amount of injected fluids. Sensitivity analysis shows that gradual reduction of the injection rate minimizes the Coulomb stress change and the least seismicity rates are predicted. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525.

Assault by burning in Jordan.

PubMed

Haddadin, W

2012-12-31

Criminal attacks by burns on women in Jordan are highlighted in this retrospective study carried out of all proved cases of criminal burns in female patients treated at the burn unit of the Royal Rehabilitation Center in Jordan between January 2005 and June 2012. Thirteen patients were included in our study, out of a total of 550 patients admitted, all in the age range of 16-45 yr. Of these 13 women, six were burned by acid throwing, five by hot water, and two by direct flames from fuel thrown over them. Burn percentage ranged from 15 to 75% of the total body surface area, with involvement in most cases of the face and upper trunk. The mean hospital stay was 33 days and the mortality rate was 3/13, i.e. 23%. Violence against women exists in Jordanian society, yet burning assaults are rare. Of these, burning by throwing acid is the most common and most disfiguring act, with a higher mortality rate in domestic environments.

Assault by burning in Jordan

PubMed Central

Haddadin, W.

2012-01-01

Summary Criminal attacks by burns on women in Jordan are highlighted in this retrospective study carried out of all proved cases of criminal burns in female patients treated at the burn unit of the Royal Rehabilitation Center in Jordan between January 2005 and June 2012. Thirteen patients were included in our study, out of a total of 550 patients admitted, all in the age range of 16-45 yr. Of these 13 women, six were burned by acid throwing, five by hot water, and two by direct flames from fuel thrown over them. Burn percentage ranged from 15 to 75% of the total body surface area, with involvement in most cases of the face and upper trunk. The mean hospital stay was 33 days and the mortality rate was 3/13, i.e. 23%. Violence against women exists in Jordanian society, yet burning assaults are rare. Of these, burning by throwing acid is the most common and most disfiguring act, with a higher mortality rate in domestic environments. PMID:23766757

Slip rates on San Francisco Bay area faults from anelastic deformation of the continental lithosphere

USGS Publications Warehouse

Geist, E.L.; Andrews, D.J.

2000-01-01

Long-term slip rates on major faults in the San Francisco Bay area are predicted by modeling the anelastic deformation of the continental lithosphere in response to regional relative plate motion. The model developed by Bird and Kong [1994] is used to simulate lithospheric deformation according to a Coulomb frictional rheology of the upper crust and a dislocation creep rheology at depth. The focus of this study is the long-term motion of faults in a region extending from the creeping section of the San Andreas fault to the south up to the latitude of Cape Mendocino to the north. Boundary conditions are specified by the relative motion between the Pacific plate and the Sierra Nevada - Great Valley microplate [Argus and Gordon, 2000]. Rheologic-frictional parameters are specified as independent variables, and prediction errors are calculated with respect to geologic estimates of slip rates and maximum compressive stress directions. The model that best explains the region-wide observations is one in which the coefficient of friction on all of the major faults is less than 0.15, with the coefficient of friction for the San Andreas fault being approximately 0.09, consistent with previous inferences of San Andreas fault friction. Prediction error increases with lower fault friction on the San Andreas, indicating a lower bound of ??SAF > 0.08. Discrepancies with respect to previous slip rate estimates include a higher than expected slip rate along the peninsula segment of the San Andreas fault and a slightly lower than expected slip rate along the San Gregorio fault.

History of fault slip and interaction with deltaic depostion from the middle Miocene to the Present - Barataria Fault, coastal Louisiana

NASA Astrophysics Data System (ADS)

McLindon, C.

2017-12-01

The Barataria fault is a major component of the Terrebonne Trough, a structural system of faults and salt domes underlying coastal Louisiana. High-quality 3-D seismic reflection data, industry well logs, micro-paleontological data and published literature on regional depositional patterns are integrated to provide an evolutionary history of the Barataria fault. The fault is a segment within a series of south-dipping normal faults that define the northern boundary of the Terrebonne Trough. The fault segment tips at depth interact with the Lake Washington and Bay de Chene salt domes, which appear to have limited its along-strike length. This study shows that the Barataria fault has exhibited continuous but episodic slip since at least the middle Miocene and through the present. Periods of maximum rates of fault slip are related to periods of maximum rates of sediment accumulation associated with Miocene deltaic deposition. The expansion of interval thickness between biostratigraphic markers in the hanging wall section of the fault relative to the footwall section (expansion index) indicate that rates of subsidence on the footwall during active fault slip were substantially greater than on the footwall. Pliocene-Pleistocene stratigraphic intervals exhibiting lower expansion indexes indicate that the fault remained active, but with a pattern of slower slip rate in which stratigraphic thickening was more limited to the area immediately adjacent to the fault. The Barataria fault defines the modern-day width of Barataria Bay, and also has a surface expression in the coastal marsh indicating that recent episodic slip has been associated with patterns of Holocene deltaic deposition.

Late Pleistocene intraplate extension of the Central Anatolian Plateau, Turkey: Inferences from cosmogenic exposure dating of alluvial fan, landslide and moraine surfaces along the Ecemiş Fault Zone

NASA Astrophysics Data System (ADS)

Yildirim, Cengiz; Akif Sarikaya, Mehmet; Ciner, Attila

2016-04-01

Late Pleistocene activity of the Ecemiş Fault Zone is integrally tied to ongoing intraplate crustal deformation in the Central Anatolian Plateau. Here we document the vertical displacement, slip rate, extension rate, and geochronology of normal faults within a narrow strip along the main strand of the fault zone. The Kartal, Cevizlik and Lorut faults are normal faults that have evident surface expression within the strip. Terrestrial cosmogenic nuclide geochronology reveals that the Kartal Fault deformed a 104.2 ± 16.5 ka alluvial fan surface and the Cevizlik Fault deformed 21.9 ± 1.8 ka glacial moraine and talus fan surfaces. The Cevizlik Fault delimits mountain front of the Aladaglar and forms >1 km relief. Our topographic surveys indicate 13.1 ± 1.4 m surface breaking vertical displacements along Cevizlik Faults, respectively. Accordingly, we suggest a 0.60 ± 0.08 mm a-1 slip rate and 0.35 ± 0.05 mm a-1 extension rate for the last 21.9 ± 1.8 ka on the Cevizlik Fault. Taken together with other structural observations in the region, we believe that the Cevizlik, Kartal ve Lorut faults are an integral part of intraplate crustal deformation in Central Anatolia. They imply that intraplate structures such as the Ecemiş Fault Zone may change their mode through time; presently, the Ecemiş Fault Zone has been deformed predominantly by normal faults. The presence of steep preserved fault scarps along the Kartal, Cevizlik and Lorut faults point to surface breaking normal faulting away from the main strand and particularly signify that these structures need to be taken into account for regional seismic hazard assessments. This project is supported by The Scientific and Technological Research Council of Turkey (TUBITAK, Grant number: 112Y087).

Evaluation of the thickness of the medial ulnar collateral ligament in junior high and high school baseball players.

PubMed

Nagamoto, Hideaki; Yamamoto, Nobuyuki; Kurokawa, Daisuke; Takahashi, Hiroyuki; Muraki, Takayuki; Tanaka, Minoru; Koike, Yoichi; Sano, Hirotaka; Itoi, Eiji

2015-07-01

Thickening of the medial ulnar collateral ligament in the throwing arm of adult baseball players is a well-known phenomenon. However, onset of the thickening is unclear among young baseball players. The purpose of this study was to evaluate the thickness of the medial ulnar collateral ligament in junior high and high school baseball players. Seventy-one uninjured and asymptomatic junior high and high school baseball players were included in the study. Participants underwent physical examination after completing a questionnaire, followed by ultrasonographic evaluation. The thickness of the medial ulnar collateral ligament was measured bilaterally. The thickness of the throwing and non-throwing sides in high school and junior high school baseball players, and within each group, was compared and statistically analyzed. The medial ulnar collateral ligament in the throwing arm of high school baseball players was thicker than that in the non-throwing arm (5.5 vs. 4.4 mm), although no significant difference was seen in junior high school baseball players. High school baseball players showed a significantly thicker medial ulnar collateral ligament in the throwing arm than junior high school baseball players. Thickening of the medial ulnar collateral ligament in the throwing arm of asymptomatic and uninjured baseball players may begin by the time the players reach high school.

Kinematic patterns underlying disguised movements: Spatial and temporal dissimilarity compared to genuine movement patterns.

PubMed

Helm, Fabian; Munzert, Jörn; Troje, Nikolaus F

2017-08-01

This study examined the kinematic characteristics of disguised movements by applying linear discriminant (LDA) and dissimilarity analyses to the motion data from 788 disguised and 792 non-disguised 7-m penalty throws performed by novice and expert handball field players. Results of the LDA showed that discrimination between type of throws (disguised vs. non-disguised) was more error-prone when throws were performed by experts (spatial: 4.6%; temporal: 29.6%) compared to novices (spatial: 1.0%; temporal: 20.2%). The dissimilarity analysis revealed significantly smaller spatial dissimilarities and variations between type of throws in experts compared to novices (p<0.001), but also showed that these spatial dissimilarities and variations increased significantly in both groups the closer the throws came to the moment of (predicted) ball release. In contrast, temporal dissimilarities did not differ significantly between groups. Thus, our data clearly demonstrate that expertise in disguising one's own action intentions results in an ability to perform disguised penalty throws that are highly similar to genuine throws. We suggest that this expertise depends mainly on keeping spatial dissimilarities small. However, the attempt to disguise becomes a challenge the closer one gets to the action outcome (i.e., ball release) becoming visible. Copyright © 2017 Elsevier B.V. All rights reserved.

The Relationship of Throwing Arm Mechanics and Elbow Varus Torque: Within-Subject Variation for Professional Baseball Pitchers Across 82,000 Throws.

PubMed

Camp, Christopher L; Tubbs, Travis G; Fleisig, Glenn S; Dines, Joshua S; Dines, David M; Altchek, David W; Dowling, Brittany

2017-11-01

Likely due to the high level of strain exerted across the elbow during the throwing motion, elbow injuries are on the rise in baseball. To identify at-risk athletes and guide postinjury return-to-throw programs, a better understanding of the variables that influence elbow varus torque is desired. To describe the within-subject relationship between elbow varus torque and arm slot and arm rotation in professional baseball pitchers. Descriptive laboratory study. A total of 81 professional pitchers performed 82,000 throws while wearing a motusBASEBALL sensor and sleeve. These throws represented a combination of throw types, such as warm-up/catch, structured long-toss, bullpen throwing from a mound, and live game activity. Variables recorded for each throw included arm slot (angle of the forearm relative to the ground at ball release), arm speed (maximal rotational velocity of the forearm), arm rotation (maximal external rotation of the throwing arm relative to the ground), and elbow varus torque. Linear mixed-effects models and likelihood ratio tests were used to estimate the relationship between elbow varus torque and arm slot, arm speed, and arm rotation within individual pitchers. All 3 metrics-arm slot (χ 2 = 428, P < .001), arm speed (χ 2 = 57,683, P < .001), and arm rotation (χ 2 = 1392, P < .001)-were found to have a significant relationship with elbow varus torque. Within individual athletes, a 1-N.m increase in elbow varus torque was associated with a 13° decrease in arm slot, a 116 deg/s increase in arm speed, and an 8° increase in arm rotation. Elbow varus torque increased significantly as pitchers increased their arm rotation during the arm cocking phase, increased the rotational velocity of their arm during the arm acceleration phase of throwing, and decreased arm slot at ball release. Thus, shoulder flexibility, arm speed, and elbow varus torque (and likely injury risk) are interrelated and should be considered collectively when treating pitchers. It is well established that elbow varus torque is related to ulnar collateral ligament injuries in overhead throwers. This study describes the relationship of arm slot, arm speed, and arm rotation to elbow varus torque in an attempt to identify modifiable risk factors for injury.

Late Holocene slip rate and ages of prehistoric earthquakes along the Maacama Fault near Willits, Mendocino County, northern California

USGS Publications Warehouse

Prentice, Carol S.; Larsen, Martin C.; Kelsey, Harvey M.; Zachariasen, Judith

2014-01-01

The Maacama fault is the northward continuation of the Hayward–Rodgers Creek fault system and creeps at a rate of 5.7±0.1  mm/yr (averaged over the last 20 years) in Willits, California. Our paleoseismic studies at Haehl Creek suggest that the Maacama fault has produced infrequent large earthquakes in addition to creep. Fault terminations observed in several excavations provide evidence that a prehistoric surface‐rupturing earthquake occurred between 1060 and 1180 calibrated years (cal) B.P. at the Haehl Creek site. A folding event, which we attribute to a more recent large earthquake, occurred between 790 and 1060 cal B.P. In the last 560–690 years, a buried channel deposit has been offset 4.6±0.2  m, giving an average slip rate of 6.4–8.6  mm/yr, which is higher than the creep rate over the last 20 years. The difference between this slip rate and the creep rate suggests that coseismic slip up to 1.7 m could have occurred after the formation of the channel deposit and could be due to a paleoearthquake known from paleoseismic studies in the Ukiah Valley, about 25 km to the southeast. Therefore, we infer that at least two, and possibly three, large earthquakes have occurred at the Haehl Creek site since 1180 cal B.P. (770 C.E.), consistent with earlier studies suggesting infrequent, large earthquakes on the Maacama fault. The short‐term geodetic slip rate across the Maacama fault zone is approximately twice the slip rate that we have documented at the Haehl Creek site, which is averaged over the last approximately 600 years. If the geodetic rate represents the long‐term slip accumulation across the fault zone, then we infer that, in the last ∼1200 years, additional earthquakes may have occurred either on the Haehl Creek segment of the Maacama fault or on other active faults within the Maacama fault zone at this latitude.

Evidence for a high slip rate of the Calico fault in the Eastern California Shear Zone

NASA Astrophysics Data System (ADS)

Xie, S.; Wetmore, P. H.; Owen, L. A.; Gallant, E.; Dixon, T. H.

2016-12-01

Fault slip rates provide important constraint on seismic hazard assessments. Geologic and geodetic estimates of slip rates across the Eastern California Shear Zone (ECSZ) reveal a discrepancy between the two data sets. Most studies attempting to reconcile the discrepancy have focused on off-fault deformation and the technique limitation of short-term geodetic measurements, while there is less concern about the relatively small number of cited geologic slip rates. The Calico fault is central fault in the Mojave Desert portion of the ECSZ, where published geologic slip rates are between 1 and 2 mm/yr. We determine new geologic slip rates of the Calico fault by dating two offset alluvial fans near the town of Newberry Springs, California. Correlation of the offset fans was based on geomorphic and soil development characteristics. Offset magnitudes are based on high-resolution topography and orthoimagery, and by cropping and matching the alluvial fans along the fault trace. Surface displacements of the two offset fans are 80 m and 1120 m. Surface exposure ages of alluvial fan samples are dated using the production of 10Be terrestrial cosmogenic nuclide (TCN). The fan with an 80 m offset produced an age of 40 ka, yielding a slip rate of 2 mm/yr, consistent with previous studies. The fan with displacement of 1120 m produced an age of 290 ka, yielding a slip rate of 4 mm/yr, indicating that the Calico fault likely had a much higher slip rate early and has decreased more recently.

Earthquake Clustering on Normal Faults: Insight from Rate-and-State Friction Models

NASA Astrophysics Data System (ADS)

Biemiller, J.; Lavier, L. L.; Wallace, L.

2016-12-01

Temporal variations in slip rate on normal faults have been recognized in Hawaii and the Basin and Range. The recurrence intervals of these slip transients range from 2 years on the flanks of Kilauea, Hawaii to 10 kyr timescale earthquake clustering on the Wasatch Fault in the eastern Basin and Range. In addition to these longer recurrence transients in the Basin and Range, recent GPS results there also suggest elevated deformation rate events with recurrence intervals of 2-4 years. These observations suggest that some active normal fault systems are dominated by slip behaviors that fall between the end-members of steady aseismic creep and periodic, purely elastic, seismic-cycle deformation. Recent studies propose that 200 year to 50 kyr timescale supercycles may control the magnitude, timing, and frequency of seismic-cycle earthquakes in subduction zones, where aseismic slip transients are known to play an important role in total deformation. Seismic cycle deformation of normal faults may be similarly influenced by its timing within long-period supercycles. We present numerical models (based on rate-and-state friction) of normal faults such as the Wasatch Fault showing that realistic rate-and-state parameter distributions along an extensional fault zone can give rise to earthquake clusters separated by 500 yr - 5 kyr periods of aseismic slip transients on some portions of the fault. The recurrence intervals of events within each earthquake cluster range from 200 to 400 years. Our results support the importance of stress and strain history as controls on a normal fault's present and future slip behavior and on the characteristics of its current seismic cycle. These models suggest that long- to medium-term fault slip history may influence the temporal distribution, recurrence interval, and earthquake magnitudes for a given normal fault segment.

Incremental Holocene slip rates from the Hope fault at Hossack Station, Marlborough fault zone, South Island, New Zealand

NASA Astrophysics Data System (ADS)

Hatem, A. E.; Dolan, J. F.; Langridge, R.; Zinke, R. W.; McGuire, C. P.; Rhodes, E. J.; Van Dissen, R. J.

2015-12-01

The Marlborough fault system, which links the Alpine fault with the Hikurangi subduction zone within the complex Australian-Pacific plate boundary zone, partitions strain between the Wairau, Awatere, Clarence and Hope faults. Previous best estimates of dextral strike-slip along the Hope fault are ≤ ~23 mm/yr± 4 mm/year. Those rates, however, are poorly constrained and could be improved using better age determinations in conjunction with measurements of fault offsets using high-resolution imagery. In this study, we use airborne lidar- and field-based mapping together with the subsurface geometry of offset channels at the Hossack site 12 km ESE of Hanmer Springs to more precisely determine stream offsets that were previously identified by McMorran (1991). Specifically, we measured fault offsets of ~10m, ~75 m, and ~195m. Together with 65 radiocarbon ages on charcoal, peat, and wood and 25 pending post-IR50-IRSL225 luminescence ages from the channel deposits, these offsets yield three different fault slip rates for the early Holocene, the late Holocene, and the past ca. 500-1,000 years. Using the large number of age determinations, we document in detail the timing of initiation and abandonment of each channel, enhancing the geomorphic interpretation at the Hossack site as channels deform over many earthquake cycles. Our preliminary incremental slip rate results from the Hossack site may indicate temporally variable strain release along the Hope fault. This study is part of a broader effort aimed at determining incremental slip rates and paleo-earthquake ages and displacements from all four main Marlborough faults. Collectively, these data will allow us to determine how the four main Marlborough faults have work together during Holocene-late Pleistocene to accommodate plate-boundary deformation in time and space.

Inferring fault rheology from low-frequency earthquakes on the San Andreas

USGS Publications Warehouse

Beeler, Nicholas M.; Thomas, Amanda; Bürgmann, Roland; Shelly, David R.

2013-01-01

Families of recurring low-frequency earthquakes (LFEs) within nonvolcanic tremor (NVT) on the San Andreas fault in central California show strong sensitivity to shear stress induced by the daily tidal cycle. LFEs occur at all levels of the tidal shear stress and are in phase with the very small, ~400 Pa, stress amplitude. To quantitatively explain the correlation, we use a model from the existing literature that assumes the LFE sources are small, persistent regions that repeatedly fail during shear of a much larger scale, otherwise aseismically creeping fault zone. The LFE source patches see tectonic loading, creep of the surrounding fault which may be modulated by the tidal stress, and direct tidal loading. If the patches are small relative to the surrounding creeping fault then the stressing is dominated by fault creep, and if patch failure occurs at a threshold stress, then the resulting seismicity rate is proportional to the fault creep rate or fault zone strain rate. Using the seismicity rate as a proxy for strain rate and the tidal shear stress, we fit the data with possible fault rheologies that produce creep in laboratory experiments at temperatures of 400 to 600°C appropriate for the LFE source depth. The rheological properties of rock-forming minerals for dislocation creep and dislocation glide are not consistent with the observed fault creep because strong correlation between small stress perturbations and strain rate requires perturbation on the order of the ambient stress. The observed tidal modulation restricts ambient stress to be at most a few kilopascal, much lower than rock strength. A purely rate dependent friction is consistent with the observations only if the product of the friction rate dependence and effective normal stress is ~ 0.5 kPa. Extrapolating the friction rate strengthening dependence of phyllosilicates (talc) to depth would require the effective normal stress to be ~50 kPa, implying pore pressure is lithostatic. If the LFE source is on the order of tens of meters, as required by the model, rate-weakening friction rate dependence (e.g., olivine) at 400 to 600°C requires that the minimum effective pressure at the LFE source is ~ 2.5 MPa.

Crustal strain near the Big Bend of the San Andreas Fault: Analysis of the Los Padres-Tehachapi Trilateration Networks, California

NASA Astrophysics Data System (ADS)

Eberhart-Phillips, Donna; Lisowski, Michael; Zoback, Mark D.

1990-02-01

In the region of the Los Padres-Tehachapi geodetic network, the San Andreas fault (SAF) changes its orientation by over 30° from N40°W, close to that predicted by plate motion for a transform boundary, to N73°W. The strain orientation near the SAF is consistent with right-lateral shear along the fault, with maximum shear rate of 0.38±0.01 μrad/yr at N63°W. In contrast, away from the SAF the strain orientations on both sides of the fault are consistent with the plate motion direction, with maximum shear rate of 0.19±0.01 μrad/yr at N44°W. The strain rate does not drop off rapidly away from the fault, and thus the area is fit by either a broad shear zone below the SAF or a single fault with a relatively deep locking depth. The fit to the line length data is poor for locking depth d less than 25 km. For d of 25 km a buried slip rate of 30 ± 6 mm/yr is estimated. We also estimated buried slip for models that included the Garlock and Big Pine faults, in addition to the SAF. Slip rates on other faults are poorly constrained by the Los Padres-Tehachapi network. The best fitting Garlock fault model had computed left-lateral slip rate of 11±2 mm/yr below 10 km. Buried left-lateral slip of 15±6 mm/yr on the Big Pine fault, within the Western Transverse Ranges, provides significant reduction in line length residuals; however, deformation there may be more complicated than a single vertical fault. A subhorizontal detachment on the southern side of the SAF cannot be well constrained by these data. We investigated the location of the SAF and found that a vertical fault below the surface trace fits the data much better than either a dipping fault or a fault zone located south of the surface trace.

Hayward Fault rate constraints at Berkeley: Evaluation of the 335-meter Strawberry Creek offset

NASA Astrophysics Data System (ADS)

Williams, P. L.

2007-12-01

At UC Berkeley the active channel of Strawberry Creek is offset 335 meters by the Hayward fault and two abandoned channels of Strawberry Creek are laterally offset 580 and 730 meters. These relationships record the displacement of the northern Hayward fault at Berkeley over a period of tens of millennia. The Strawberry Creek site has a similar geometry to the central San Andreas fault's Wallace Creek site, which arguably provides the best geological evidence of "millennial" fault kinematics in California (Sieh and Jahns, 1984). Slip rate determinations are an essential component of overall hazard evaluation for the Hayward fault, and this site is ripe to disclose a long-term form of this parameter, to contrast with geodetic and other geological rate evidence. Large offsets at the site may lower uncertainty in the rate equation relative to younger sites, as the affect of stream abandonment age, generally the greatest source of rate uncertainty, is greatly reduced. This is helpful here because it more-than-offsets uncertainties resulting from piercing projections to the fault. Strawberry Creek and its ancestral channels suggest west-side-up vertical deformation across the Hayward fault at this location. The development of the vertical deformation parameter will complement ongoing geodetic measurements, particularly InSAR, and motivate testing of other geological constraints. Up-to-the-west motion across the Hayward fault at Berkeley has important implications for the partitioning of strain and kinematics of the northern Hayward fault, and may explain anomalous up-on-the-west landforms elsewhere along the fault. For example, geological features of the western Berkeley Hills are consistent with rapid and recent uplift to the west of the fault. On the basis of a preliminary analysis of the offset channels of Strawberry Creek, up-to-the-west uplift is about 0.5mm/yr across the Hayward fault at Berkeley. If this is in fact the long-term rate, the 150 m height of the Hills to the northwest of the Strawberry Creek site was produced during the past about 300,000 years by a significant dip- slip (thrust) component of Hayward fault motion. Rapid and recent uplift of some portions of the East Bay Hills has important implications for fault geometries and slope stability, and should strongly influence the investigation fault hazards in areas that are more complexly deformed.

Effects of Six Weeks of Medicine Ball Training on Throwing Velocity, Throwing Precision, and Isokinetic Strength of Shoulder Rotators in Female Handball Players.

PubMed

Raeder, Christian; Fernandez-Fernandez, Jaime; Ferrauti, Alexander

2015-07-01

The aim of this study was to investigate the effects of 6 weeks of medicine ball training (MBT) on throwing velocity, throwing precision, and isokinetic strength of shoulder rotators in competitive female handball players. Twenty-eight players (mean ± SD; age: 20.8 ± 3.3 years, height: 170.5 ± 5.6 cm, body mass: 65.2 ± 8.0 kg) were randomly assigned to an MBT group (TG; n = 15) and a control group (CG; n = 13). TG performed a supervised MBT program, 3 times a week for a total of 6 weeks, focusing on handball-specific movement patterns. Both groups, TG and CG, also conducted a supervised shoulder injury prevention program with elastic tubes, as part of the warm-up, finishing with regular handball throws. Results showed a significant group × time interaction in throwing velocity (p < 0.001) with the TG posttest results being significantly higher compared with CG (d = 2.1), and also a significant main time effect (p < 0.001), with an increase in throwing velocity of 14% (d = 3.0) and 3.7% (d = 0.3) for both TG and CG, respectively. Throwing precision did not significantly differ between groups and time points. Isokinetic strength measures revealed a significant group × time interaction (p ≤ 0.05) with the TG posttest results being significantly higher compared with CG (d = 0.9) and also a significant main time effect (p < 0.01) with an increase of 15% (d = 0.9) in concentric shoulder internal rotation at 180°·s⁻¹ in the dominant arm in TG, whereas no significant changes occurred in CG. The present results indicate that 6 weeks of MBT elicit significant improvements in functional performance (i.e., throwing velocity) in female handball players, whereas throwing precision remained unaffected. Medicine ball training exercises seem to be a useful and inexpensive strength training strategy in enhancing functional performance by closely mimicking sport-specific movement activities.

Where Are You Throwing the Ball? I Better Watch Your Body, Not Just Your Arm!

PubMed

Maselli, Antonella; Dhawan, Aishwar; Cesqui, Benedetta; Russo, Marta; Lacquaniti, Francesco; d'Avella, Andrea

2017-01-01

The ability to intercept or avoid a moving object, whether to catch a ball, snatch one's prey, or avoid the path of a predator, is a skill that has been acquired throughout evolution by many species in the animal kingdom. This requires processing early visual cues in order to program anticipatory motor responses tuned to the forthcoming event. Here, we explore the nature of the early kinematics cues that could inform an observer about the future direction of a ball projected with an unconstrained overarm throw. Our goal was to pinpoint the body segments that, throughout the temporal course of the throwing action, could provide key cues for accurately predicting the side of the outgoing ball. We recorded whole-body kinematics from twenty non-expert participants performing unconstrained overarm throws at four different targets placed on a vertical plane at 6 m distance. In order to characterize the spatiotemporal structure of the information embedded in the kinematics of the throwing action about the outgoing ball direction, we introduced a novel combination of dimensionality reduction and machine learning techniques. The recorded kinematics clearly shows that throwing styles differed considerably across individuals, with corresponding inter-individual differences in the spatio-temporal structure of the thrower predictability. We found that for most participants it is possible to predict the region where the ball hit the target plane, with an accuracy above 80%, as early as 400-500 ms before ball release. Interestingly, the body parts that provided the most informative cues about the action outcome varied with the throwing style and during the time course of the throwing action. Not surprisingly, at the very end of the action, the throwing arm is the most informative body segment. However, cues allowing for predictions to be made earlier than 200 ms before release are typically associated to other body parts, such as the lower limbs and the contralateral arm. These findings are discussed in the context of the sport-science literature on throwing and catching interactive tasks, as well as from the wider perspective of the role of sensorimotor coupling in interpersonal social interactions.

Faults in parts of north-central and western Houston metropolitan area, Texas

USGS Publications Warehouse

Verbeek, Earl R.; Ratzlaff, Karl W.; Clanton, Uel S.

1979-01-01

Hundreds of residential, commercial, and industrial structures in the Houston metropolitan area have sustained moderate to severe damage owing to their locations on or near active faults. Paved roads have been offset by faults at hundreds of locations, butted pipelines have been distorted by fault movements, and fault-induced gradient changes in drainage lines have raised concern among flood control engineers. Over 150 faults, many of them moving at rates of 0.5 to 2 cm/yr, have been mapped in the Houston area; the number of faults probably far exceeds this figure.This report includes a map of eight faults, in north-central and western Houston, at a scale useful for land-use planning. Seven of the faults, are known, to be active and have caused considerable damage to structures built on or near them. If the eighth fault is active, it may be of concern to new developments on the west side of Houston. A ninth feature shown on the map is regarded only as a possible fault, as an origin by faulting has not been firmly established.Seismic and drill-hold data for some 40 faults, studied in detail by various investigators have verified connections between scarps at the land surface and growth faults in the shallow subsurface. Some scarps, then, are known to be the surface manifestations of faults that have geologically long histories of movement. The degree to which natural geologic processes contribute to current fault movement, however, is unclear, for some of man’s activities may play a role in faulting as well.Evidence that current rates of fault movement far exceed average prehistoric rates and that most offset of the land surface in the Houston area has occurred only within the last 50 years indirectly suggest that fluid withdrawal may be accelerating or reinitiating movement on pre-existing faults. This conclusion, however, is based only on a coincidence in time between increased fault activity and increased rates of withdrawal of water, oil, and gas from subsurface sediments; no cause-and-effect relationship has been demonstrated. An alternative hypothesis is that natural fault movements are characterized by short—term episodicity and that Houston is experiencing the effects of a brief period of accelerated natural fault movement. Available data from monitored faults are insufficient to weigh the relative importance of natural vs. induced fault movements.

Earth Observations taken by Expedition 30 crewmember

NASA Image and Video Library

2012-01-14

ISS030-E-035487 (14 Jan. 2012) --- The East African Rift Valley in Kenya is featured in this image photographed by an Expedition 30 crew member on the International Space Station. This photograph highlights classical geological structures associated with a tectonic rift valley, in this case the Eastern Branch of the East African Rift near Kenya’s southern border with Tanzania and just south of the Equator. The East African Rift is one of the great tectonic features of Africa, caused by fracturing of Earth’s crust. The Nubian (or African) plate includes the older continental crust of Africa to the west, while the Somalian plate that is moving away includes the Horn of Africa to the northeast; the tectonic boundary stretches from the southern Red Sea to central Mozambique. Landscapes in the rift valley can appear confusing. The most striking features in this view are the numerous, nearly parallel, linear fault lines that occupy the floor of the valley (most of the image). Shadows cast by the late afternoon sun make the fault scarps (steps in the landscape caused by slip motion along individual faults) more prominent. The faults are aligned with the north-south axis of the valley (lower left to top right). A secondary trend of less linear faults cuts the main fault trend at an acute angle, the fault steps throwing large shadows. The Eastern Branch of the East African Rift is arid (compared with the Western Branch which lies on the border of the Congolese rainforest). Evidence of this can be seen in the red, salt-loving algae of the shallow and salty Lake Magadi (center). A neighboring small lake to the north has deeper water and appears dark in the image. The white salt deposits of the dry part of the Lake Magadi floor (center) host a few small commercial salt pans. The lakes appear to be located where the main and secondary fault trends intersect. The East African rift system is marked by substantial volcanic activity, including lavas erupted from fissures along the rift in the region. Much of the faulting observed in this image cuts through such lavas. Elsewhere along the rift system individual volcanoes form. Some of those volcanoes are very large, including Mt. Kilimanjaro and Mt. Kenya. In this image, rising 400 meters above the valley floor, a volcano appears to be superimposed on the faults—indicating that the volcano is younger than the faults it covers. Deeply eroded slopes also suggest that the volcano has not been active for a long time. The largest vegetated area (lower left)—in an desert zone with no vegetation visible to the naked eye from space—is the green floor of a valley which drains an area large enough for water to exist near the surface so that plants can thrive. For a sense of scale, the vegetated valley floor is 17 kilometers long (10.5 miles).

Determination of tectonic shortening rates from progressively deformed flights of terraces above the Chelungpu and Changhua thrust ramps, Taiwan

NASA Astrophysics Data System (ADS)

Yue, L.; Suppe, J.

2007-12-01

The Chelungpu and Changhua thrust ramps in central Taiwan show contrasting hanging-wall structural geometries that suggest different kinematics, even though they involve the same stratigraphic section and basal detachment. The Chelungpu thrust shows a classic fault-bend folding geometry, which predicts folding solely by kink-band migration, whereas the hanging wall of the Changhua thrust demonstrates the characteristic geometry of a shear fault-bend folding, which predicts a progressive limb rotation with minor kink-band migration. We test the kinematic predictions of classic and shear fault-bend folding theories by analyzing deformed flights of terraces and coseismic displacements in the Mw=7.6 Chi-Chi earthquake. The Chelungpu terraces shows differences in uplift magnitudes across active axial surfaces that closely approximate the assumptions of classical fault-bend folding, including constant fault-parallel displacement, implying conservation of bed length, and hanging-wall uplift rates that are proportional to the sine of the fault dip. This provides a basis for precise determination of total fault slip since the formation of each terrace and combined with terrace dating gives long- term fault-slip rates for the Chelungpu thrust system. An estimation of the long term fault-slip rate of the Chelungpu thrust in the north Hsinshe terrace yields 15 mm/yr over the last 55 ka, which is similar to the combined shortening rate of 16 mm/y on the Chelungpu and Chushiang thrusts in the south estimated by Simoes et al. in 2006. Evan the coseismic displacements of 3 to 9m in the Chi-Chi earthquake are approximately fault-parallel but have additional transient components that are averaged out over the timescale of terrace deformation, which represents 10-100 large earthquakes. In contrast, terrace deformation in the hanging wall of the Changhua thrust ramp shows progressive limb rotation, as predicted from its shear fault-bend folding geometry, which combined with terrace dating allows an estimation of the long term fault-slip rate of 21 mm/yr over the last 31 ka. A combined shortening rate of 37 mm/yr is obtained for this part of the western Taiwan thrust belt, which is about 45 percent of the total plate-tectonic shortening rate across Taiwan. The Changhua shear fault-bend fold ramp is in the early stages of its development with only 1.7km total displacement whereas the Chelungpu classical fault-bend folding ramp in the same stratigraphy has nearly an order of magnitude more displacement (~14 km). We suggest that shear fault-bend folding may be favored mechanically at low displacement, whereas classical fault-bend folding would be favored at large displacement.

Determination of tectonic shortening rates from progressively deformed flights of terraces above the Chelungpu and Changhua thrust ramps, Taiwan

NASA Astrophysics Data System (ADS)

Yue, L.; Suppe, J.

2004-12-01

The Chelungpu and Changhua thrust ramps in central Taiwan show contrasting hanging-wall structural geometries that suggest different kinematics, even though they involve the same stratigraphic section and basal detachment. The Chelungpu thrust shows a classic fault-bend folding geometry, which predicts folding solely by kink-band migration, whereas the hanging wall of the Changhua thrust demonstrates the characteristic geometry of a shear fault-bend folding, which predicts a progressive limb rotation with minor kink-band migration. We test the kinematic predictions of classic and shear fault-bend folding theories by analyzing deformed flights of terraces and coseismic displacements in the Mw=7.6 Chi-Chi earthquake. The Chelungpu terraces shows differences in uplift magnitudes across active axial surfaces that closely approximate the assumptions of classical fault-bend folding, including constant fault-parallel displacement, implying conservation of bed length, and hanging-wall uplift rates that are proportional to the sine of the fault dip. This provides a basis for precise determination of total fault slip since the formation of each terrace and combined with terrace dating gives long- term fault-slip rates for the Chelungpu thrust system. An estimation of the long term fault-slip rate of the Chelungpu thrust in the north Hsinshe terrace yields 15 mm/yr over the last 55 ka, which is similar to the combined shortening rate of 16 mm/y on the Chelungpu and Chushiang thrusts in the south estimated by Simoes et al. in 2006. Evan the coseismic displacements of 3 to 9m in the Chi-Chi earthquake are approximately fault-parallel but have additional transient components that are averaged out over the timescale of terrace deformation, which represents 10-100 large earthquakes. In contrast, terrace deformation in the hanging wall of the Changhua thrust ramp shows progressive limb rotation, as predicted from its shear fault-bend folding geometry, which combined with terrace dating allows an estimation of the long term fault-slip rate of 21 mm/yr over the last 31 ka. A combined shortening rate of 37 mm/yr is obtained for this part of the western Taiwan thrust belt, which is about 45 percent of the total plate-tectonic shortening rate across Taiwan. The Changhua shear fault-bend fold ramp is in the early stages of its development with only 1.7km total displacement whereas the Chelungpu classical fault-bend folding ramp in the same stratigraphy has nearly an order of magnitude more displacement (~14 km). We suggest that shear fault-bend folding may be favored mechanically at low displacement, whereas classical fault-bend folding would be favored at large displacement.

Effect of Core Training on Male Handball Players’ Throwing Velocity

PubMed Central

García-Ruiz, José; Cortell-Tormo, Juan Manuel; Tortosa-Martínez, Juan

2017-01-01

Abstract In handball, throwing velocity is considered to be one of the essential factors in achieving the ultimate aim of scoring a goal. The objective of the present study was to analyze the effect of a core training program on throwing velocity in 30 handball players (age 18.7 ± 3.4 years, body height 179.3 ± 7.0 cm, body mass 78.9 ± 7.7 kg), 16 of whom were in the junior category and 14 of whom were in the senior category. The 30 players were randomly divided into two groups, the control group (n = 15) and the experimental group (n = 15). For a period of ten weeks, both groups attended their regular handball training sessions (four per week), but in addition, the experimental group participated in a program specifically aimed at progressively strengthening the lumbo-pelvic region and consisting of seven exercises performed after the general warm-up in each regular session. Pre- and post-tests were carried out to analyze each player’s throwing velocity from different throwing positions and thus assess the effects of this specific training program. Statistically significant differences (p ≤ 0.05) in throwing velocity were observed between the experimental group, which presented a percentage improvement of 4.5%, and the control group, which did not show any improvement. The results seem to indicate that an increase in the strength and stability of the lumbo-pelvic region can contribute to an improvement in the kinetic chain of the specific movement of throwing in handball, thus, increasing throwing velocity. PMID:28469756

Effect of Core Training on Male Handball Players' Throwing Velocity.

PubMed

Manchado, Carmen; García-Ruiz, José; Cortell-Tormo, Juan Manuel; Tortosa-Martínez, Juan

2017-02-01

In handball, throwing velocity is considered to be one of the essential factors in achieving the ultimate aim of scoring a goal. The objective of the present study was to analyze the effect of a core training program on throwing velocity in 30 handball players (age 18.7 ± 3.4 years, body height 179.3 ± 7.0 cm, body mass 78.9 ± 7.7 kg), 16 of whom were in the junior category and 14 of whom were in the senior category. The 30 players were randomly divided into two groups, the control group (n = 15) and the experimental group (n = 15). For a period of ten weeks, both groups attended their regular handball training sessions (four per week), but in addition, the experimental group participated in a program specifically aimed at progressively strengthening the lumbo-pelvic region and consisting of seven exercises performed after the general warm-up in each regular session. Pre- and post-tests were carried out to analyze each player's throwing velocity from different throwing positions and thus assess the effects of this specific training program. Statistically significant differences (p ≤ 0.05) in throwing velocity were observed between the experimental group, which presented a percentage improvement of 4.5%, and the control group, which did not show any improvement. The results seem to indicate that an increase in the strength and stability of the lumbo-pelvic region can contribute to an improvement in the kinetic chain of the specific movement of throwing in handball, thus, increasing throwing velocity.

The differences in frontal midline theta power between successful and unsuccessful basketball free throws of elite basketball players.

PubMed

Chuang, Lan-Ya; Huang, Chung-Ju; Hung, Tsung-Min

2013-12-01

During the preparatory period of motor skill, attention is considered as one of the most vital factors for athletic performance. Electroencephalographic (EEG) indices, such as occipital α, have been employed to explore the psychological state during the preparatory period in elite athletes. The main purpose of this study was to investigate the differences in frontal midline theta (Fm θ) power during the aiming period between successful and unsuccessful basketball free throws. Fifteen skilled male basketball players were recruited and asked to perform free throws. Electroencephalogram (EEG) data were collected 2seconds prior to the initiation of the free throw and segmented into four 0.5-s epochs. The lower theta (θ1, 4-6Hz) and upper theta (θ2, 6-8Hz) power values was contrasted between the successful and unsuccessful throws. Two 2×4×6 (performance×time×electrode) ANOVAs with repeated measures were conducted separately for θ1 and θ2 power. The results indicate that θ1 power at the Fz site and θ2 power at the Fz and the F4 sites fluctuated significantly during the preparatory period for an unsuccessful throw when compared with a successful throw. Additionally, a higher Fm θ2 power was observed at the beginning of the aiming period of a successful throw. This study suggests that a stable arousal and a relatively constant amount of attention to the task prior to motor execution may facilitate athletic performance. Crown Copyright © 2013. All rights reserved.

In vitro evaluation of square and surgeon's knots in large gauge suture.

PubMed

Gillen, Alex M; Munsterman, Amelia S; Farag, Ramsis; Coleridge, Matthew O D; Hanson, R Reid

2017-02-01

To investigate the strength and size of surgeon's and square knots for starting and ending continuous suture lines using large gauge suture. In vitro mechanical study. Knotted suture. Surgeon's and square knots were tested using 2 and 3 USP polyglactin 910 and 2 USP polydioxanone under linear tension on a universal testing machine. Failure mode and knot holding capacity (KHC) were recorded, and relative knot security (RKS) was calculated as a percentage of KHC. Comparisons were made between number of throws, suture size, suture type, and knot types. Knot volume and weight were assessed by a digital micrometer and balance, respectively. There were no significant differences in KHC (P = .295), RKS (P = .307), volume (P = .128), or weight (P = .310) between square and surgeon's knots at the start or end of suture lines with the same number of throws and suture type. A minimum of 6 throws were required for start knots and 7 throws at end knots to prevent unraveling. Knots tied with 3 polyglactin 910 were strongest (P < .001) and 2 polyglactin 910 produced knots with higher KHC and RKS than 2 polydioxanone (P < .001). No consistent differences were detected between knots types tied with the same suture material; however, number of throws affected KHC and RKS up to 6 throws in start or 7 throws in end knots. The configuration of square and surgeon's knots performed at the end of a continuous line alters their KHC, supporting the use of additional throws for knot security. © 2017 The American College of Veterinary Surgeons.

Coulomb Stress Accumulation along the San Andreas Fault System

NASA Technical Reports Server (NTRS)

Smith, Bridget; Sandwell, David

2003-01-01

Stress accumulation rates along the primary segments of the San Andreas Fault system are computed using a three-dimensional (3-D) elastic half-space model with realistic fault geometry. The model is developed in the Fourier domain by solving for the response of an elastic half-space due to a point vector body force and analytically integrating the force from a locking depth to infinite depth. This approach is then applied to the San Andreas Fault system using published slip rates along 18 major fault strands of the fault zone. GPS-derived horizontal velocity measurements spanning the entire 1700 x 200 km region are then used to solve for apparent locking depth along each primary fault segment. This simple model fits remarkably well (2.43 mm/yr RMS misfit), although some discrepancies occur in the Eastern California Shear Zone. The model also predicts vertical uplift and subsidence rates that are in agreement with independent geologic and geodetic estimates. In addition, shear and normal stresses along the major fault strands are used to compute Coulomb stress accumulation rate. As a result, we find earthquake recurrence intervals along the San Andreas Fault system to be inversely proportional to Coulomb stress accumulation rate, in agreement with typical coseismic stress drops of 1 - 10 MPa. This 3-D deformation model can ultimately be extended to include both time-dependent forcing and viscoelastic response.

Climate change and mountain-front morphology: Estimating Late Glacial to Holocene erosion rates from the shape of fault-bounded hillslopes

NASA Astrophysics Data System (ADS)

Tucker, G. E.; McCoy, S. W.; Whittaker, A. C.; Roberts, G.; Lancaster, S. T.; Phillips, R. J.

2011-12-01

The existence of well-preserved Holocene bedrock fault scarps along active normal faults in the Mediterranean region and elsewhere suggests a dramatic reduction in rates of rock weathering and erosion that correlates with the transition from glacial to interglacial climate. We test and quantify this interpretation using a case study in the Italian Central Apennines. Holocene rates are derived from measurements of weathering-pit depth along the Magnola scarp, where previous cosmogenic 36Cl analyses constrain exposure history. To estimate the average hillslope erosion rate over ˜105 years, we introduce a simple geometric model of normal-fault footwall slope evolution. The model predicts that the gradient of a weathering-limited footwall hillslope is set by fault dip angle and by the ratio of slip rate to erosion rate; if either slip or erosion rate is known, the other can be derived. Applying this model to the Magnola fault yields an estimated average weathering rate on the order of 0.2-0.4 mm/yr, more than 10x higher than either the Holocene scarp weathering rate or modern regional limestone weathering rates. A numerical model of footwall growth and erosion, in which erosion rate tracks the oxygen-isotope curve, reproduces the main features of hillslope and scarp morphology and suggests that the hillslope erosion rate has varied by about a factor of 30 over the past one to two glacial cycles. We conclude that preservation of carbonate fault scarps reflects strong climatic control on rock breakdown by frost cracking.

Developmental Gender Differences for Overhand Throwing in Aboriginal Australian Children

ERIC Educational Resources Information Center

Thomas, Jerry R.; Alderson, Jacqueline A.; Thomas, Katherine T.; Campbell, Amity C.; Elliott, Bruce C.

2010-01-01

In a review of 46 meta-analyses of gender differences, overhand throwing had the largest gender difference favoring boys (ES greater than 3.0). Expectations for gender-specific performances may be less pronounced in female Australian Aborigines, because historical accounts state they threw for defense and hunting. Overhand throwing velocities and…

46 CFR 160.040-4 - Equipment for impulse-projected rocket type line-throwing appliance.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Equipment for impulse-projected rocket type line...-Throwing Appliance, Impulse-Projected Rocket Type (and Equipment) § 160.040-4 Equipment for impulse-projected rocket type line-throwing appliance. (a) Four rocket projectiles, each complete with bridle and...

46 CFR 160.040-4 - Equipment for impulse-projected rocket type line-throwing appliance.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Equipment for impulse-projected rocket type line...-Throwing Appliance, Impulse-Projected Rocket Type (and Equipment) § 160.040-4 Equipment for impulse-projected rocket type line-throwing appliance. (a) Four rocket projectiles, each complete with bridle and...

46 CFR 160.040-4 - Equipment for impulse-projected rocket type line-throwing appliance.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Equipment for impulse-projected rocket type line...-Throwing Appliance, Impulse-Projected Rocket Type (and Equipment) § 160.040-4 Equipment for impulse-projected rocket type line-throwing appliance. (a) Four rocket projectiles, each complete with bridle and...

46 CFR 160.040-4 - Equipment for impulse-projected rocket type line-throwing appliance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Equipment for impulse-projected rocket type line...-Throwing Appliance, Impulse-Projected Rocket Type (and Equipment) § 160.040-4 Equipment for impulse-projected rocket type line-throwing appliance. (a) Four rocket projectiles, each complete with bridle and...

46 CFR 160.040-4 - Equipment for impulse-projected rocket type line-throwing appliance.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Equipment for impulse-projected rocket type line...-Throwing Appliance, Impulse-Projected Rocket Type (and Equipment) § 160.040-4 Equipment for impulse-projected rocket type line-throwing appliance. (a) Four rocket projectiles, each complete with bridle and...

Reduction of errors during practice facilitates fundamental movement skill learning in children with intellectual disabilities.

PubMed

Capio, C M; Poolton, J M; Sit, C H P; Eguia, K F; Masters, R S W

2013-04-01

Children with intellectual disabilities (ID) have been found to have inferior motor proficiencies in fundamental movement skills (FMS). This study examined the effects of training the FMS of overhand throwing by manipulating the amount of practice errors. Participants included 39 children with ID aged 4-11 years who were allocated into either an error-reduced (ER) training programme or a more typical programme in which errors were frequent (error-strewn, ES). Throwing movement form, throwing accuracy, and throwing frequency during free play were evaluated. The ER programme improved movement form, and increased throwing activity during free play to a greater extent than the ES programme. Furthermore, ER learners were found to be capable of engaging in a secondary cognitive task while manifesting robust throwing accuracy performance. The findings support the use of movement skills training programmes that constrain practice errors in children with ID, suggesting that such approach results in improved performance and heightened movement engagement in free play. © 2012 The Authors. Journal of Intellectual Disability Research © 2012 Blackwell Publishing Ltd.

Skill-dependent proximal-to-distal sequence in team-handball throwing.

PubMed

Wagner, Herbert; Pfusterschmied, Jürgen; Von Duvillard, Serge P; Müller, Erich

2012-01-01

The importance of proximal-to-distal sequencing in human performance throwing has been reported previously. However, a comprehensive comparison of the proximal-to-distal sequence in team-handball throwing in athletes with different training experience and competition is lacking. Therefore, the aim of the study was to compare the ball velocity and proximal-to-distal sequence in the team-handball standing throw with run-up of players of different skill (less experienced, experienced, and elite). Twenty-four male team-handball players (n = 8 for each group) performed five standing throws with run-up with maximal ball velocity and accuracy. Kinematics and ball trajectories were recorded with a Vicon motion capture system and joint movements were calculated. A specific proximal-to-distal sequence, where elbow flexion occurred before shoulder internal rotation, was found in all three groups. These results are in line with previous studies in team-handball. Furthermore, the results of the present study suggest that in the team-handball standing throw with run-up, increased playing experience is associated with an increase in ball velocity as well as a delayed start to trunk flexion.

Late Holocene slip rate of the San Andreas fault and its accommodation by creep and moderate-magnitude earthquakes at Parkfield, California

USGS Publications Warehouse

Toke, N.A.; Arrowsmith, J.R.; Rymer, M.J.; Landgraf, A.; Haddad, D.E.; Busch, M.; Coyan, J.; Hannah, A.

2011-01-01

Investigation of a right-laterally offset channel at the Miller's Field paleoseismic site yields a late Holocene slip rate of 26.2 +6.4/-4.3 mm/yr (1??) for the main trace of the San Andreas fault at Park-field, California. This is the first well-documented geologic slip rate between the Carrizo and creeping sections of the San Andreas fault. This rate is lower than Holocene measurements along the Carrizo Plain and rates implied by far-field geodetic measurements (~35 mm/yr). However, the rate is consistent with historical slip rates, measured to the northwest, along the creeping section of the San Andreas fault (<30 mm/yr). The paleoseismic exposures at the Miller's Field site reveal a pervasive fabric of clay shear bands, oriented clockwise oblique to the San Andreas fault strike and extending into the upper-most stratigraphy. This fabric is consistent with dextral aseismic creep and observations of surface slip from the 28 September 2004 M6 Parkfield earthquake. Together, this slip rate and deformation fabric suggest that the historically observed San Andreas fault slip behavior along the Parkfield section has persisted for at least a millennium, and that significant slip is accommodated by structures in a zone beyond the main San Andreas fault trace. ?? 2011 Geological Society of America.

Temporal slip rate variability in the Lower Rhine Embayment, Northwest Europe

NASA Astrophysics Data System (ADS)

Gold, Ryan; Kuebler, Simon; Friedrich, Anke

2016-04-01

Low strain regions may be characterized by long periods of seismic quiescence, punctuated by periods of clustered earthquake activity. This type of non-periodic recurrence behavior challenges accurate seismic hazard analysis. The Lower Rhine Embayment in the German-Belgium-Netherland border region presents a unique opportunity to characterize the long-term record of faulting to evaluate the periodicity of earthquake occurrence in a low strain region. The Lower Rhine Embayment is covered by a high-resolution record of Quaternary terraces associated with the Rhine and Maas (Meuse) Rivers and their tributaries. These terraces are cut by numerous NW-trending faults and record cumulative displacements that exceed 100 m in numerous locations. In this study, we exploit this rich record of faulted fluvial terraces and find convincing evidence for temporally varying rates of Quaternary fault movement across the Lower Rhine Embayment. First, we document a significant increase in vertical fault slip rates since 700 ka, compared to the average slip rate since the start of the Quaternary using the top and base of the Main Terrace, respectively. Increases in slip rate exceed 500% along many of the faults, including the Swist/Erft, Stockheim, Viersen, Sandgewand, and Kirspenich fault systems. This increase in fault slip rate corresponds to a regional period of increased tectonic uplift of the Rhenish Massif, increased volcanism in Eifel, and incision of the Rhine River. In a second and related analysis, we synthesize terrace offset and age information from the Feldbiss fault system along the western boundary of the Lower Rhine Embayment, which transects a flight of Quaternary terraces associated with the Mass river. This analysis reveals evidence for secular variation in slip rate. In particular, we identify two periods of higher slip rate (800-400 ka and 130-100 ka), where fault slip rate exceeds the longer-term average slip rate of 0.04-0.05 mm/yr by as much as a factor of two. These results show that in the Lower Rhine Embayment low-strain region, the tempo of strain release (and therefore earthquakes) is non-steady. This variable slip behavior should be incorporated into future efforts to characterize seismic hazard across the region.

New Constraints on Models for Time-Variable Displacement Rates on the San Jacinto Fault Zone, Southern California

NASA Astrophysics Data System (ADS)

Anderson, M.; Bennett, R.; Matti, J.

2004-12-01

Existing geodetic, geomorphic, and geologic studies yield apparently conflicting estimates of fault displacement rates over the last 1.5 m.y. in the greater San Andreas fault (SAF) system of southern California. Do these differences reflect biases in one or more of the inference methods, or is fault displacement really temporally variable? Arguments have been presented for both cases. We investigate the plausibility of variable-rate fault models by combining basin deposit provenance, fault trenching, seismicity, gravity, and magnetic data sets from the San Bernardino basin. These data allow us to trace the path and broad timing of strike-slip fault displacements in buried basement rocks, which in turn allows us to test weather variable-fault rate models fit the displacement path and rate data through the basin. The San Bernardino basin lies between the San Jacinto fault (SJF) and the SAF. Isostatic gravity signatures show a 2 km deep graben centered directly over the modern strand of the SJF, whereas the basin is shallow and a-symmetric next to the SAF. This observation indicates that stresses necessary to create the basin have been centered on the SJF for most of the basin's history. Linear magnetic anomalies, used as geologic markers, are offset ˜25 km across the northernmost strands of the SJF, which matches offset estimations south of the basin. These offset anomalies indicate that the SJF and SAF are discrete fault systems that do not directly interact south of the San Gabriel Mountains, therefore spatial slip variability combined with sparse sampling cannot explain the conflicting rate data. Furthermore, analyses of basin deposits indicate that movement on the SJF began between 1.3 to1.5 Ma, yielding an over-all average displacement rate in the range of 17 to 19 mm/yr, which is higher than some shorter-term estimates based on geodesy and geomorphology. Average displacement rates over this same time period for the San Bernardino strand of the SAF, on the other hand, are inferred to be low, consistent with some recent short-term estimates based on geodesy, but in contrast with estimates based on geomorphology. We conclude that either published estimates for the short-term SJF displacement rate do not accurately reflect the full SJF rate, or that the SJF rate has decreased over time, with implications for rate changes on other faults in the region. We explore the latter explanation with models for time-variable displacement rate for the greater SAF system that satisfy all existing data.

Near-fault peak ground velocity from earthquake and laboratory data

USGS Publications Warehouse

McGarr, A.; Fletcher, Joe B.

2007-01-01

We test the hypothesis that peak ground velocity (PGV) has an upper bound independent of earthquake magnitude and that this bound is controlled primarily by the strength of the seismogenic crust. The highest PGVs, ranging up to several meters per second, have been measured at sites within a few kilometers of the causative faults. Because the database for near-fault PGV is small, we use earthquake slip models, laboratory experiments, and evidence from a mining-induced earthquake to investigate the factors influencing near-fault PGV and the nature of its scaling. For each earthquake slip model we have calculated the peak slip rates for all subfaults and then chosen the maximum of these rates as an estimate of twice the largest near-fault PGV. Nine slip models for eight earthquakes, with magnitudes ranging from 6.5 to 7.6, yielded maximum peak slip rates ranging from 2.3 to 12 m/sec with a median of 5.9 m/sec. By making several adjustments, PGVs for small earthquakes can be simulated from peak slip rates measured during laboratory stick-slip experiments. First, we adjust the PGV for differences in the state of stress (i.e., the difference between the laboratory loading stresses and those appropriate for faults at seismogenic depths). To do this, we multiply both the slip and the peak slip rate by the ratio of the effective normal stresses acting on fault planes measured at 6.8 km depth at the KTB site, Germany (deepest available in situ stress measurements), to those acting on the laboratory faults. We also adjust the seismic moment by replacing the laboratory fault with a buried circular shear crack whose radius is chosen to match the experimental unloading stiffness. An additional, less important adjustment is needed for experiments run in triaxial loading conditions. With these adjustments, peak slip rates for 10 stick-slip events, with scaled moment magnitudes from -2.9 to 1.0, range from 3.3 to 10.3 m/sec, with a median of 5.4 m/sec. Both the earthquake and laboratory results are consistent with typical maximum peak slip rates averaging between 5 and 6 m/sec or corresponding maximum near-fault PGVs between 2.5 and 3 m/sec at seismogenic depths, independent of magnitude. Our ability to replicate maximum slip rates in the fault zones of earthquakes by adjusting the corresponding laboratory rates using the ratio of effective normal stresses acting on the fault planes suggests that the strength of the seismogenic crust is the important factor limiting the near-fault PGV.

Mid-humerus adaptation in fast pitch softballers and the impact of throwing mechanics

PubMed Central

Bogenschutz, Elizabeth D.; Smith, Heather D.; Warden, Stuart J.

2011-01-01

Purpose Throwing is a vigorous activity that generates large internal loads. There is limited evidence of the effect of these loads on bone adaptation. The aim of this study was to investigate the: 1) magnitude of bone adaptation within the midshaft humerus of female fast-pitch softball players and 2) influence of throwing mechanics (windmill vs. overhand throwing) on the magnitude of adaptation. Methods Midshaft humeral bone mass, structure and estimated strength were assessed via peripheral quantitative computed tomography in fast-pitch softball players (throwers; n=15) and matched controls (controls; n=15). The effect of throwing was examined by comparing dominant-to-nondominant differences in throwers to controls, while the influence of mechanics was determined by comparing dominant-to-nondominant differences in throwers who primarily play as pitcher (windmill thrower), catcher (overhand thrower) or fielder (overhand thrower). Results Throwers had greater dominant-to-nondominant difference in midshaft humeral bone mass, structure and estimated strength relative to controls (all P<0.05). The largest effect was for estimated torsional strength with throwers having a mean dominant-to-nondominant difference of 22.5% (range, 6.7% to 43.9%) compared to 4.4% (range, -8.3% to 17.5%) in controls (P<0.001). Throwing mechanics appeared to influence the magnitude of skeletal adaptation, with overhand throwers having more than double dominant-to-nondominant difference in midshaft humeral bone mass, structure and estimated strength than windmill throwers (all P<0.05). Conclusion Throwing induces substantial skeletal adaptation at the midshaft humerus of the dominant upper extremity. Throwing mechanics appears to the influence the magnitude of adaptation as catchers and fielders (overhand throwers) had twice as much adaptation as pitchers (windmill throwers). The latter finding may have implications for skeletal injury risk at the midshaft humerus in throwing athletes. PMID:21311354

Effects of 4-Week Training Intervention with Unknown Loads on Power Output Performance and Throwing Velocity in Junior Team Handball Players.

PubMed

Sabido, Rafael; Hernández-Davó, Jose Luis; Botella, Javier; Moya, Manuel

2016-01-01

To compare the effect of 4-week unknown vs known loads strength training intervention on power output performance and throwing velocity in junior team handball players. Twenty-eight junior team-handball players (17.2 ± 0.6 years, 1.79 ± 0.07 m, 75.6 ± 9.4 kg)were divided into two groups (unknown loads: UL; known loads: KL). Both groups performed two sessions weekly consisting of four sets of six repetitions of the bench press throw exercise, using the 30%, 50% and 70% of subjects' individual 1 repetition maximum (1RM). In each set, two repetitions with each load were performed, but the order of the loads was randomised. In the KL group, researchers told the subjects the load to mobilise prior each repetition, while in the UL group, researchers did not provide any information. Maximal dynamic strength (1RM bench press), power output (with 30, 50 and 70% of 1RM) and throwing velocity (7 m standing throw and 9 m jumping throw) were assessed pre- and post-training intervention. Both UL and KL group improved similarly their 1RM bench press as well as mean and peak power with all loads. There were significant improvements in power developed in all the early time intervals measured (150 ms) with the three loads (30, 50, 70% 1RM) in the UL group, while KL only improved with 30% 1RM (all the time intervals) and with 70% 1RM (at certain time intervals). Only the UL group improved throwing velocity in both standing (4.7%) and jumping (5.3%) throw (p > 0.05). The use of unknown loads has led to greater gains in power output in the early time intervals as well as to increases in throwing velocity compared with known loads. Therefore unknown loads are of significant practical use to increase both strength and in-field performance in a short period of training.

Differences in anthropometric characteristics in relation to throwing velocity and competitive level in professional male team handball: a tool for talent profiling.

PubMed

Fieseler, Georg; Hermassi, Souhail; Hoffmeyer, Birgit; Schulze, Stephan; Irlenbusch, Lars; Bartels, Thomas; Delank, Karl-Stefan; Laudner, Kevin G; Schwesig, René

2017-01-01

The primary aim of the study was to examine the anthropometric characteristics as well as throwing and sprinting performance of professional handball players classified by playing position and competition level. 21 male players (age: 25.2±5.1 years) from the first German handball league (FGL) and 34 male players (age: 26.1±4.1 years) from the third German handball league (TGL) were categorized as backs, pivots, wings and goalkeepers. Measurements included anthropometric data (height, mass and body mass index (BMI)), throwing and sprinting performance selected out of a complex handball test (HBCT), which was conducted twice (2 rounds). During the HBCT, the subjects performed two sprints (10, 20 m), two standing throws with run-up (ST) and four vertical jump throws (VJT) over a hurdle (20 cm) with and without precision for goal shot. The anthropometric data revealed a significantly (P=0.038 and η2=0.079) shorter body height for TGL than for FGL players. In the cohort of first league athletes the pivots were the tallest (1.98±0.04 m), backs in the third league showed the maximum body height (1.90±0.05 m). Regarding body mass, pivots were the heaviest players independent from the league membership. The FGL players showed a significantly (P<0.05 and η2>0.10) higher throwing velocity in all type of throws. Body height was significantly related to ST (r=0.53) and VJT (r=0.52) in the first round of HBCT but only for the FGL athletes. Throwing velocity was also correlated with BMI (r=-0.50) among the TGL players. Substantial differences of body characteristics, throwing and sprinting performance between playing positions and competitive levels underline the importance of a careful scouting and position-specific training for professional handball players.

Comparison of the quench and fault current limiting characteristics of the flux-coupling type SFCL with single and three-phase transformer

NASA Astrophysics Data System (ADS)

Jung, Byung Ik; Cho, Yong Sun; Park, Hyoung Min; Chung, Dong Chul; Choi, Hyo Sang

2013-01-01

The South Korean power grid has a network structure for the flexible operation of the system. The continuously increasing power demand necessitated the increase of power facilities, which decreased the impedance in the power system. As a result, the size of the fault current in the event of a system fault increased. As this increased fault current size is threatening the breaking capacity of the circuit breaker, the main protective device, a solution to this problem is needed. The superconducting fault current limiter (SFCL) has been designed to address this problem. SFCL supports the stable operation of the circuit breaker through its excellent fault-current-limiting operation [1-5]. In this paper, the quench and fault current limiting characteristics of the flux-coupling-type SFCL with one three-phase transformer were compared with those of the same SFCL type but with three single-phase transformers. In the case of the three-phase transformers, both the superconducting elements of the fault and sound phases were quenched, whereas in the case of the single-phase transformer, only that of the fault phase was quenched. For the fault current limiting rate, both cases showed similar rates for the single line-to-ground fault, but for the three-wire earth fault, the fault current limiting rate of the single-phase transformer was over 90% whereas that of the three-phase transformer was about 60%. It appears that when the three-phase transformer was used, the limiting rate decreased because the fluxes by the fault current of each phase were linked in one core. When the power loads of the superconducting elements were compared by fault type, the initial (half-cycle) load was great when the single-phase transformer was applied, whereas for the three-phase transformer, its power load was slightly lower at the initial stage but became greater after the half fault cycle.

Active tectonics of the Binalud Mountains, a key puzzle segment to describe Quaternary deformations at the northeastern boundary of the Arabia-Eurasia collision

NASA Astrophysics Data System (ADS)

Shabanian, Esmaeil; Bellier, Olivier; Siame, Lionel L.; Abbassi, Mohammad R.; Leanni, Laetitia; Braucher, Régis; Farbod, Yassaman; Bourlès, Didier L.

2010-05-01

In northeast Iran, the Binalud Mountains accommodate part of active convergence between the Arabian and Eurasian plates. This fault-bounded mountain range has been considered a key region to describe Quaternary deformations at the northeastern boundary of the Arabia-Eurasia collision. But, the lack of knowledge on active faulting hampered evaluating the geological reliability of tectonic models describing the kinematics of deformation in northeast Iran. Morphotectonic investigations along both sides of the Binalud Mountains allowed us to characterize the structural and active faulting patterns along the Neyshabur and Mashhad fault systems on the southwest and northeast sides of the mountain range, respectively. We applied combined approaches of morphotectonic analyses based on satellite imageries (SPOT5 and Landsat ETM+), STRM and site-scale digital topographic data, and field surveys complemented with in situ-produced 10Be exposure dating to determine the kinematics and rate of active faulting. Three regional episodes of alluvial surface abandonments were dated at 5.3±1.1 kyr (Q1), 94±5 kyr (Q3), and 200±14 kyr (S3). The geomorphic reconstruction of both vertical and right-lateral fault offsets postdating these surface abandonment episodes yielded Quaternary fault slip rates on both sides of the Binalud Mountains. On the Neyshabur Fault System, thanks to geomorphic reconstructions of cumulative offsets recorded by Q3 fan surfaces, slip rates of 2.7±0.8 mm/yr and 2.4±0.2 mm/yr are estimated for right-lateral and reverse components of active faulting, respectively. Those indicate a total slip rate of 3.6±1.2 mm/yr for the late Quaternary deformation on the southwest flank of the Binalud Mountains. Reconstructing the cumulative right-lateral offset recorded by S3 surfaces, a middle-late Quaternary slip rate of 1.6±0.1 mm/yr is determined for the Mashhad Fault System. Altogether, our geomorphic observations reveal that, on both sides of the Binalud Mountains, the relative motion between central Iran and Eurasia is partly taken-up by dextral-reverse oblique-slip faulting along the Neyshabur and Mashhad fault systems. This faulting mechanism implies a long-term rate of ~4 mm/yr for the range-parallel strike-slip faulting, and an uplift rate of ~2.4 mm/yr due to the range-normal shortening during late Quaternary. Our data provide the first geological constraints on the rate of active faulting on both sides of the Binalud Mountains, and allow us to examine the geological reliability of preexisting tectonic models proposed to describe the kinematics of active deformation at the northeastern boundary of the Arabia-Eurasia collision. Our results favor the northward translation of central Iran with respect to Eurasia through strike-slip faulting localized along distinct crustal scale fault systems rather than systematic block rotations around vertical axes.

Linking Incoming Plate Faulting and Intermediate Depth Seismicity

NASA Astrophysics Data System (ADS)

Kwong, K. B.; van Zelst, I.; Tong, X.; Eimer, M. O.; Naif, S.; Hu, Y.; Zhan, Z.; Boneh, Y.; Schottenfels, E.; Miller, M. S.; Moresi, L. N.; Warren, J. M.; Wiens, D. A.

2017-12-01

Intermediate depth earthquakes, occurring between 70-350 km depth, are often attributed to dehydration reactions within the subducting plate. It is proposed that incoming plate normal faulting associated with plate bending at the trench may control the amount of hydration in the plate by producing large damage zones that create pathways for the infiltration of seawater deep into the subducting mantle. However, a relationship between incoming plate seismicity, faulting, and intermediate depth seismicity has not been established. We compiled a global dataset consisting of incoming plate earthquake moment tensor (CMT) solutions, focal depths, bend fault spacing and offset measurements, along with plate age and convergence rates. In addition, a global intermediate depth seismicity dataset was compiled with parameters such as the maximum seismic moment and seismicity rate, as well as thicknesses of double seismic zones. The maximum fault offset in the bending region has a strong correlation with the intermediate depth seismicity rate, but a more modest correlation with other parameters such as convergence velocity and plate age. We estimated the expected rate of seismic moment release for the incoming plate faults using mapped fault scarps from bathymetry. We compare this with the cumulative moment from normal faulting earthquakes in the incoming plate from the global CMT catalog to determine whether outer rise fault movement has an aseismic component. Preliminary results from Tonga and the Middle America Trench suggest there may be an aseismic component to incoming plate bending faulting. The cumulative seismic moment calculated for the outer rise faults will also be compared to the cumulative moment from intermediate depth earthquakes to assess whether these parameters are related. To support the observational part of this study, we developed a geodynamic numerical modeling study to systematically explore the influence of parameters such as plate age and convergence rate on the offset, depth, and spacing of outer rise faults. We then compare these robust constraints on outer rise faulting to the observed widths of intermediate depth earthquakes globally.

Physical fault tolerance of nanoelectronics.

PubMed

Szkopek, Thomas; Roychowdhury, Vwani P; Antoniadis, Dimitri A; Damoulakis, John N

2011-04-29

The error rate in complementary transistor circuits is suppressed exponentially in electron number, arising from an intrinsic physical implementation of fault-tolerant error correction. Contrariwise, explicit assembly of gates into the most efficient known fault-tolerant architecture is characterized by a subexponential suppression of error rate with electron number, and incurs significant overhead in wiring and complexity. We conclude that it is more efficient to prevent logical errors with physical fault tolerance than to correct logical errors with fault-tolerant architecture.

Active, capable, and potentially active faults - a paleoseismic perspective

USGS Publications Warehouse

Machette, M.N.

2000-01-01

Maps of faults (geologically defined source zones) may portray seismic hazards in a wide range of completeness depending on which types of faults are shown. Three fault terms - active, capable, and potential - are used in a variety of ways for different reasons or applications. Nevertheless, to be useful for seismic-hazards analysis, fault maps should encompass a time interval that includes several earthquake cycles. For example, if the common recurrence in an area is 20,000-50,000 years, then maps should include faults that are 50,000-100,000 years old (two to five typical earthquake cycles), thus allowing for temporal variability in slip rate and recurrence intervals. Conversely, in more active areas such as plate boundaries, maps showing faults that are <10,000 years old should include those with at least 2 to as many as 20 paleoearthquakes. For the International Lithosphere Programs' Task Group II-2 Project on Major Active Faults of the World our maps and database will show five age categories and four slip rate categories that allow one to select differing time spans and activity rates for seismic-hazard analysis depending on tectonic regime. The maps are accompanied by a database that describes evidence for Quaternary faulting, geomorphic expression, and paleoseismic parameters (slip rate, recurrence interval and time of most recent surface faulting). These maps and databases provide an inventory of faults that would be defined as active, capable, and potentially active for seismic-hazard assessments.

Geometric and thermal controls on normal fault seismicity from rate-and-state friction models

NASA Astrophysics Data System (ADS)

Mark, H. F.; Behn, M. D.; Olive, J. A. L.; Liu, Y.

2017-12-01

Seismic and geodetic observations from the last two decades have led to a growing realization that a significant amount of fault slip at plate boundaries occurs aseismically, and that the amount of aseismic displacement varies across settings. Here we investigate controls on the seismogenic behavior of crustal-scale normal faults that accommodate extensional strain at mid-ocean ridges and continental rifts. Seismic moment release rates measured along the fast-spreading East Pacific Rise suggest that the majority of fault growth occurs aseismically with almost no seismic slip. In contrast, at the slow-spreading Mid-Atlantic Ridge seismic slip may represent up to 60% of the total fault displacement. Potential explanations for these variations include heterogeneous distributions of frictional properties on fault surfaces, effects of variable magma supply associated with seafloor spreading, and/or differences in fault geometry and thermal structure. In this study, we use rate-and-state friction models to study the seismic coupling coefficient (the fraction of total fault slip that occurs seismically) for normal faults at divergent plate boundaries, and investigate controls on fault behavior that might produce the variations in the coupling coefficient observed in natural systems. We find that the seismic coupling coefficient scales with W/h*, where W is the downdip width of the seismogenic area of the fault and h* is the critical earthquake nucleation size. At mid-ocean ridges, W is expected to increase with decreasing spreading rate. Thus, the observed relationship between seismic coupling and W/h* explains to first order variations in seismic coupling coefficient as a function of spreading rate. Finally, we use catalog data from the Gulf of Corinth to show that this scaling relationship can be extended into the thicker lithosphere of continental rift systems.

Upper body contributions to power generation during rapid, overhand throwing in humans.

PubMed

Roach, Neil T; Lieberman, Daniel E

2014-06-15

High-speed and accurate throwing is a distinctive human behavior. Achieving fast projectile speeds during throwing requires a combination of elastic energy storage at the shoulder, as well as the transfer of kinetic energy from proximal body segments to distal segments. However, the biomechanical bases of these mechanisms are not completely understood. We used inverse dynamics analyses of kinematic data from 20 baseball players fitted with four different braces that inhibit specific motions to test a model of power generation at key joints during the throwing motion. We found that most of the work produced during throwing is generated at the hips, and much of this work (combined with smaller contributions from the pectoralis major) is used to load elastic elements in the shoulder and power the rapid acceleration of the projectile. Despite rapid angular velocities at the elbow and wrist, the restrictions confirm that much of the power generated to produce these distal movements comes from larger proximal segments, such as the shoulder and torso. Wrist hyperextension enhances performance only modestly. Together, our data also suggest that heavy reliance on elastic energy storage may help explain some common throwing injuries and can provide further insight into the evolution of the upper body and when our ancestors first developed the ability to produce high-speed throws. © 2014. Published by The Company of Biologists Ltd.

Influence Of Opposition On Ball Velocity In The Handball Jump Throw

PubMed Central

Rivilla-Garcia, Jesús; Grande, Ignacio; Sampedro, Javier; Van Den Tillaar, Roland

2011-01-01

The purpose of the present study was to investigate the influence of different degrees of opposition on ball velocity in the jump throw in elite, amateur and adolescent team handball players. Thus, one hundred and nineteen elite, amateur and under 18 team handball players performed jump throws under three different conditions: 1) without opposition, 2) with the opposition of the goalkeeper and 3) with the opposition of the goalkeeper and a defensive player. The degree of opposition was found to have a negative effect on ball velocity in all three groups (p < 0.001). Furthermore, the level of competition had a positive effect on ball velocity (p < 0.001). However, no interaction was found between the level of competition and the degree of opposition on ball velocity (p = 0.178). The findings of this study indicate that an increase of external stimuli probably influences throwing kinematics and thereby maximal ball velocity. However, experience does not seem to be a factor that can reduce the influence of these external stimuli. Key points The degree of opposition had a negative effect upon ball throwing velocity in elite, amateur and adolescent handball players in the jump throw. It indicated that an increase of external stimuli influences the execution of throwing. Experience does not seem to be a factor that can reduce the influence of these external stimuli. PMID:24150629

Reducing errors benefits the field-based learning of a fundamental movement skill in children.

PubMed

Capio, C M; Poolton, J M; Sit, C H P; Holmstrom, M; Masters, R S W

2013-03-01

Proficient fundamental movement skills (FMS) are believed to form the basis of more complex movement patterns in sports. This study examined the development of the FMS of overhand throwing in children through either an error-reduced (ER) or error-strewn (ES) training program. Students (n = 216), aged 8-12 years (M = 9.16, SD = 0.96), practiced overhand throwing in either a program that reduced errors during practice (ER) or one that was ES. ER program reduced errors by incrementally raising the task difficulty, while the ES program had an incremental lowering of task difficulty. Process-oriented assessment of throwing movement form (Test of Gross Motor Development-2) and product-oriented assessment of throwing accuracy (absolute error) were performed. Changes in performance were examined among children in the upper and lower quartiles of the pretest throwing accuracy scores. ER training participants showed greater gains in movement form and accuracy, and performed throwing more effectively with a concurrent secondary cognitive task. Movement form improved among girls, while throwing accuracy improved among children with low ability. Reduced performance errors in FMS training resulted in greater learning than a program that did not restrict errors. Reduced cognitive processing costs (effective dual-task performance) associated with such approach suggest its potential benefits for children with developmental conditions. © 2011 John Wiley & Sons A/S.

Development and validation of a method to directly measure the cable force during the hammer throw.

PubMed

Brice, Sara M; Ness, Kevin F; Rosemond, Doug; Lyons, Keith; Davis, Mark

2008-05-01

The development of cable force during hammer-throw turns is crucial to the throw distance. In this paper, we present a method that is capable of measuring cable force in real time and, as it does not interfere with technique, it is capable of providing immediate feedback to coaches and athletes during training. A strain gauge was mounted on the wires of three hammers to measure the tension in the wire and an elite male hammer thrower executed three throws with each hammer. The output from the gauges was recorded by a data logger positioned on the lower back of the thrower. The throws were captured by three high-speed video cameras and the three-dimensional position of the hammer's head was determined by digitizing the images manually. The five best throws were analysed. The force acting on the hammer's head was calculated from Newton's second law of motion and this was compared with the force measured via the strain gauge. Qualitatively the time dependence of the two forces was essentially the same, although the measured force showed more detail in the troughs of the force-time curves. Quantitatively the average difference between the measured and calculated forces over the five throws was 76 N, which corresponds to a difference of 3.8% for a cable force of 2000 N.

Long term changes of the throwing arm of former elite javelin throwers.

PubMed

Schmitt, H; Hansmann, H J; Brocai, D R; Loew, M

2001-05-01

The aim of this study was to determine long term changes in shoulder and elbow joints of former elite javelin throwers. Twenty-one elite javelin throwers were examined at an average of 19 years after the end of their high performance phase. Mean age at examination was 50 years. Functional assessment of both shoulders was determined by the Constant-score. The shoulder of the throwing arm was examined by magnetic resonance imaging. Both elbow joints were examined clinically and radiographically. Five athletes complained about transient shoulder pain in their throwing arm affecting activities of daily living, fourteen athletes had a deficit of internal rotation of at least ten degrees. Constant-scores of throwing arms were six points lower than those of non-throwing arms (P < 0.05). Complete ruptures and partial tears of the rotator cuff were frequent. Three athletes complained about transient elbow pain in their throwing arm affecting activities of daily living; ten athletes had a deficit of extension of more than five degrees. All dominant elbows had advanced arthrotic alterations (osteophytes, sclerosis) compared to the non-dominant side. Athletes who trained with weights of more than 3 kg had a significantly higher risk of degenerative changes than athletes who did not (P < 0.01). We therefore recommend to avoid throwing training with weights of more than 3 kg.

Quaternary Activity of the Monastir and Grombalia Fault Systems in the North‒Eastern Tunisia (Seismotectonic Implication)

NASA Astrophysics Data System (ADS)

Ghribi, R.; Zaatra, D.; Bouaziz, S.

2018-01-01

The Monastir and Grombalia fault systems consist of three strands that the northern segment corresponds to Hammamet and Grombalia faults. The southern strand represents Monastir Fault also referred to as the Skanes-Khnis Fault. These NW-trends are observed continuously in the major outcropping features of north-eastern Tunisia including both the Cap Bon peninsula and the Sahel domain. Along the Hammamet Fault, the north-eastern strand of Grombalia fault system, left lateral drainage offset of amount 220 m is found in Fawara valley. To the South, the left lateral movement is occurred along the Monastir Fault based on 180 m of Tyrrhenian terrace displacement. Field observations supported by satellite images suggest that the Monastir and Grombalia fault systems appear to slip mostly laterally with components of normal dip slip. Assuming the development of the stream networks during the Riss-Würm interglacial (115000-125000 years) and the age of the Tyrrhenian terrace (121 ± 10 ka), the strike slip rates of the Hammamet and Monastir faults are calculated in the range of 1.5-1.8 mm/yr. There vertical slip rates are estimated to be 0.06 and 0.26 mm/yr, respectively. These data are consistent with the displacement rate in the Pelagian shelf (1-2 mm/yr) but they are below the convergence rate of African-Eurasian plates (8 mm/yr). Our seismotectonics study reveals that a maximum earthquake of Mw = 6.5 could occur every 470 years in the Hammamet fault zone and Mw = 6-every 263 years in the Monastir fault zone.

Slip rates and spatially variable creep on faults of the northern San Andreas system inferred through Bayesian inversion of Global Positioning System data

USGS Publications Warehouse

Murray, Jessica R.; Minson, Sarah E.; Svarc, Jerry L.

2014-01-01

Fault creep, depending on its rate and spatial extent, is thought to reduce earthquake hazard by releasing tectonic strain aseismically. We use Bayesian inversion and a newly expanded GPS data set to infer the deep slip rates below assigned locking depths on the San Andreas, Maacama, and Bartlett Springs Faults of Northern California and, for the latter two, the spatially variable interseismic creep rate above the locking depth. We estimate deep slip rates of 21.5 ± 0.5, 13.1 ± 0.8, and 7.5 ± 0.7 mm/yr below 16 km, 9 km, and 13 km on the San Andreas, Maacama, and Bartlett Springs Faults, respectively. We infer that on average the Bartlett Springs fault creeps from the Earth's surface to 13 km depth, and below 5 km the creep rate approaches the deep slip rate. This implies that microseismicity may extend below the locking depth; however, we cannot rule out the presence of locked patches in the seismogenic zone that could generate moderate earthquakes. Our estimated Maacama creep rate, while comparable to the inferred deep slip rate at the Earth's surface, decreases with depth, implying a slip deficit exists. The Maacama deep slip rate estimate, 13.1 mm/yr, exceeds long-term geologic slip rate estimates, perhaps due to distributed off-fault strain or the presence of multiple active fault strands. While our creep rate estimates are relatively insensitive to choice of model locking depth, insufficient independent information regarding locking depths is a source of epistemic uncertainty that impacts deep slip rate estimates.

Induced seismicity constraints on subsurface geological structure, Paradox Valley, Colorado

NASA Astrophysics Data System (ADS)

Block, Lisa V.; Wood, Christopher K.; Yeck, William L.; King, Vanessa M.

2015-02-01

Precise relative hypocentres of seismic events induced by long-term fluid injection at the Paradox Valley Unit (PVU) brine disposal well provide constraints on the subsurface geological structure and compliment information available from deep seismic reflection and well data. We use the 3-D spatial distribution of the hypocentres to refine the locations, strikes, and throws of subsurface faults interpre­ted previously from geophysical surveys and to infer the existence of previously unidentified subsurface faults. From distinct epicentre lineations and focal mechanism trends, we identify a set of conjugate fracture orientations consistent with shear-slip reactivation of late-Palaeozoic fractures over a widespread area, as well as an additional fracture orientation present only near the injection well. We propose simple Mohr-Coulomb fracture models to explain these observations. The observation that induced seismicity preferentially occurs along one of the identified conjugate fracture orientations can be explained by a rotation in the direction of the regional maximum compressive stress from the time when the fractures were formed to the present. Shear slip along the third fracture orientation observed near the injection well is inconsistent with the current regional stress field and suggests a local rotation of the horizontal stresses. The detailed subsurface model produced by this analysis provides important insights for anticipating spatial patterns of future induced seismicity and for evaluation of possible additional injection well sites that are likely to be seismically and hydrologically isolated from the current well. In addition, the interpreted fault patterns provide constraints for estimating the maximum magnitude earthquake that may be induced, and for building geomechanical models to simulate pore pressure diffusion, stress changes and earthquake triggering.

Interseismic strain accumulation across the Ashkabad fault (NE Iran) from MERIS-corrected ASAR data

NASA Astrophysics Data System (ADS)

Walters, R. J.; Elliott, J. R.; Li, Z.; Parsons, B. E.

2011-12-01

The right-lateral Ashkabad Fault separates deforming NE Iran from the stable Turkmenistan platform to the north, and also facilitates the north-westwards extrusion of the South Caspian block (along with the left-lateral Shahrud fault zone). The fault represents the northernmost boundary of significant deformation of the Arabia-Eurasia collision in NE Iran. The 1948 M 7.3 Ashkabad earthquake, which killed around 110,000 people and was the deadliest earthquake to hit Europe or the Middle East in the 20th Century, also possibly occurred on this fault. However, the slip rate and therefore the seismic hazard that the Ashkabad fault represents are not well known. GPS data in NE Iran are sparse, and there are no direct geological or quaternary rates for the main strand of the fault. We use Envisat ASAR data acquired between 2003 and 2010 to measure interseismic strain accumulation across the fault, and hence estimate the slip rate across it. Due to the proximity of this region to the Caspian Sea and the presence of highly variable weather systems, we use data from Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument, as well as modelled weather data from the European Centre for Medium-Range Weather Forecasting (ECMWF), to correct interferograms for differences in water vapour and atmospheric pressure. We mitigate the effects of remaining noise by summing the 13 corrected interferograms that cover the fault, effectively creating a 30 year interferogram with improved signal-to-noise ratio, and we empirically correct for orbital errors. Our measurements of rates of displacement are consistent with an interseismic model for the Ashkabad fault where deformation occurs at depth on a narrow shear zone below a layer in which the fault is locked. We invert the data to solve for best fitting model parameters, estimating both the slip rate and the depth to which the fault is locked. Our measurements show that the Ashkabad fault is accumulating strain at a rate of 9 mm/yr below a locking depth of 15 km. We use a Monte Carlo approach to estimate the errors on our best fit solution and find our data is consistent with 6-12 mm/yr slip rate and 8-25 km locking depth. Using an alternative jacknife approach we obtain ranges of 4-11 mm/yr and 9-18 km. Lyberis and Manby (1999, AAPG Bulletin 83: 1135-1160) proposed a slip rate of 3-8 mm/yr for the Ashkabad fault, based on an estimated offset and a likely age of onset for the fault. Masson et al. (2007, GJI 170:436-440) estimated a slip rate of 2-4 mm/yr from GPS data. Our best fit solution is higher, but within error our results are compatible with both of these previous estimates. In addition, GPS data from an unpublished PhD Thesis (Tavakoli, 2007, PhD Thesis, LGIT Grenoble) suggest slip rates of around 9 mm/yr, supporting our best fit slip rate.

An Optimal Basketball Free Throw

ERIC Educational Resources Information Center

Seppala-Holtzman, David

2012-01-01

A basketball player attempting a free throw has two parameters under his or her control: the angle of elevation and the force with which the ball is thrown. We compute upper and lower bounds for the initial velocity for suitable values of the angle of elevation, generating a subset of the configuration space of all successful free throws. A…

Validity and Reliability of a Medicine Ball Explosive Power Test.

ERIC Educational Resources Information Center

Stockbrugger, Barry A.; Haennel, Robert G.

2001-01-01

Evaluated the validity and reliability of a medicine ball throw test to evaluate explosive power. Data on competitive sand volleyball players who performed a medicine ball throw and a standard countermovement jump indicated that the medicine ball throw test was a valid and reliable way to assess explosive power for an analogous total-body movement…

Changing Throwing Pattern: Instruction and Control Parameter

ERIC Educational Resources Information Center

Southard, Dan

2006-01-01

The purpose of this study was to determine the effects of instruction and scaling up a control parameter (velocity of throw) on changes in throwing pattern. Sixty adult female throwers (ages 20-26 years) were randomly placed into one of four practice conditions: (a) scale up on velocity with no instruction, (b) maintain constant velocity with no…

Holocene slip rates along the San Andreas Fault System in the San Gorgonio Pass and implications for large earthquakes in southern California

NASA Astrophysics Data System (ADS)

Heermance, Richard V.; Yule, Doug

2017-06-01

The San Gorgonio Pass (SGP) in southern California contains a 40 km long region of structural complexity where the San Andreas Fault (SAF) bifurcates into a series of oblique-slip faults with unknown slip history. We combine new 10Be exposure ages (Qt4: 8600 (+2100, -2200) and Qt3: 5700 (+1400, -1900) years B.P.) and a radiocarbon age (1260 ± 60 years B.P.) from late Holocene terraces with scarp displacement of these surfaces to document a Holocene slip rate of 5.7 (+2.7, -1.5) mm/yr combined across two faults. Our preferred slip rate is 37-49% of the average slip rates along the SAF outside the SGP (i.e., Coachella Valley and San Bernardino sections) and implies that strain is transferred off the SAF in this area. Earthquakes here most likely occur in very large, throughgoing SAF events at a lower recurrence than elsewhere on the SAF, so that only approximately one third of SAF ruptures penetrate or originate in the pass.