Jasinski, M.; Stoll, J.; Cook, W.; Ondrusek, M.; Stengel, E., and Brunt, K., 2016. Inland and near-shore water profiles derived from the high-altitude Multiple Altimeter Beam Experiemental Lidar ...(MABEL). In: Brock, J.C.; Gesch, D.B.; Parrish, C.E.; Rogers, J.N., and Wright, C.W. (eds.), Advances in Topobathymetric Mapping, Models, and Applications. Journal of Coastal Research, Special Issue, No. 76, pp. 44–55. Coconut Creek (Florida), ISSN 0749-0208. The Advanced Topographic Laser Altimeter System (ATLAS) on the Ice, Cloud, and Land Elevation Satellite (ICESat-2) mission is a six beam, low energy, high repetition rate, 532-nm laser transmitter with photon counting detectors. Although designed primarily for detecting height changes in ice caps, sea ice, and vegetation, the polar-orbiting satellite will observe global surface water during its designed three-year life span, including inland water bodies, coasts, and open oceans. In preparation for the mission, an ICESat-2 prototype, the Multiple Altimeter Beam Experimental Lidar (MABEL), was built and flown on high-altitude aircraft experiments over a range of inland and near-shore targets. The purpose was to test the ATLAS concept and to provide a database for developing an algorithm that detects along track surface water height and light penetration under a range of atmospheric and water conditions. The current analysis examines the datasets of three MABEL transects observed from 20 km above ground of coastal and inland waters conducted in 2012 and 2013. Transects ranged from about 2 to 12 km in length and included the middle Chesapeake Bay, the near-shore Atlantic coast at Virginia Beach, and Lake Mead. Results indicate MABEL's high capability for retrieving surface water height statistics with a mean height precision of approximately 5–7 cm per 100-m segment length. Profiles of attenuated subsurface backscatter, characterized using a Signal to Background Ratio written in Log10 base, or LSBR0, were observed over a range of 1.3 to 9.3 m, depending on water clarity and atmospheric background. Results indicate that observable penetration depth, although primarily dependent on water properties, was greatest when the solar background rate was low. Near-shore bottom reflectance was detected only at the Lake Mead site down to a maximum of 10 m under a clear night sky and low turbidity of approximately 1.6 Nephelometric Turbidity Units (NTU). The overall results suggest that the feasibility of retrieving operational surface water height statistics from space-based photon counting systems such as ATLAS is very high for resolutions down to about 100 m, even in partly cloudy conditions. The capability to observe subsurface backscatter profiles is achievable but requires much longer transects of several hundreds of meters.
The current cycle of global warming has contracted some range restricted species while concurrently expanding the range of more adaptable species. Sabal minor is a member of Arecaceae, the palm ...family, and is confined to lower latitudes in both western hemispheres. Latitudinal limitation of S. minor is believed to be related to low temperature intolerance. However the exact mechanism remains elusive. In this study reproductive fecundity of anthropogenically introduced populations in southern Virginia Beach, Virginia, was evaluated. Diaspore viability, approximated by floatability of fruits, was used to evaluate distribution by hydrochory. This study also documents a previously unidentified condition of fungal mass growth around the fruits of S. minor during buoyancy testing and suggests some areas for additional investigation.
With support from the US National Tsunami Hazard Mitigation Program (NTHMP), the authors have been developing tsunami inundation maps for the upper US East Coast (USEC), using high-resolution ...numerical modeling. These maps are envelopes of maximum elevations, velocity, or momentum flux, caused by the probable maximum tsunamis identified in the Atlantic oceanic basin, including from far-field coseismic or volcanic sources, and near-field Submarine mass failures (SMFs); the latter are the object of this work. Despite clear field evidence of past large-scale SMFs within our area of interest, such as the Currituck slide complex, their magnitude, pre-failed geometry, volume, and mode of rupture are poorly known. A screening analysis based on the Monte Carlo simulations (MCS) identified areas for possible tsunamigenic SMF sources along the USEC, indicating an increased level of tsunami hazard north of Virginia, potentially surpassing the inundation generated by a typical 100-year hurricane storm surge in the region, as well as that from the most extreme far-field coseismic sources in the Atlantic; to the south, the MCS indicated that SMF tsunami hazard significantly decreased. Subsequent geotechnical and geological analyses delimited four high-risk areas along the upper USEC where the potential for large tsunamigenic SMFs, identified in the MCS, was realistic on the basis of field data (i.e., sediment nature and volume/availability). In the absence of accurate site-specific field data, following NTHMP’s recommendation, for the purpose of simulating tsunami hazard from SMF PMTs, we parameterized an extreme SMF source in each of the four areas as a so-called Currituck proxy, i.e., a SMF having the same volume, dimensions, and geometry as the historical SMF. In this paper, after briefly describing our state-of-the-art SMF tsunami modeling methodology, in a second part, we parameterize and model the historical Currituck event, including: (1) a new reconstruction of the SMF geometry and kinematics; (2) the simulation of the resulting tsunami source generation; and (3) the propagation of the tsunami source over the shelf to the coastline, in a series of nested grids. A sensitivity analysis to model and grid parameters is performed on this case, to ensure convergence and accuracy of tsunami simulation results. Then, we model in greater detail and discuss the impact of the historical Currituck tsunami event along the nearest coastline where its energy was focused, off of Virginia Beach and Norfolk, as well as near the mouth of the Chesapeake Bay; our results are in qualitative agreement with an earlier modeling study. In a third part, following the same methodology, we model tsunami generation and propagation for SMF Currituck proxy sources sited in the four identified areas of the USEC. Finally, as an illustration of our SMF tsunami hazard assessment work, we present detailed tsunami inundation maps, as well as some other products, for one of the most impacted and vulnerable areas, near and around Ocean City, MD. We find that coastal inundation from near-field SMF tsunamis may be comparable to that caused by the largest far-field sources. Because of their short propagation time and, hence, warning times, SMF tsunamis may pose one of the highest coastal hazards for many highly populated and vulnerable communities along the upper USEC, certainly comparable to that from extreme hurricanes.
Effects of strain rate on the stress–strain and subsequent stress relaxation behaviors have been studied by performing triaxial compression tests on dense Virginia Beach sand specimens at three ...different strain rates (ratio of 256 between the slowest and the fastest) under low and high confining pressures. For the tests performed under low confining pressure, the specimens that were initially sheared at a faster rate showed a slightly higher amount of stress relaxation, but almost identical stress–strain behaviors were achieved. For tests performed under high confining pressure, the same amount of strength was achieved at high axial strains (10% to 20%), but specimens sheared at higher strain rates showed a slightly stiffer stress–strain response at low axial strains (up to 10%). Similar to the tests performed under low confining pressure, higher strain rates produced higher amounts of stress relaxation to some extent. Effects of correction of axial strain due to load cell expansion and drainage condition during stress relaxation have also been studied and the results indicated that correction of axial strain and undrained condition will both increase the observed amount of stress relaxation. Moreover, a 1 day stress relaxation curve was obtained by connecting the ending stress–strain points of six stress relaxation tests initiated at different deviator stress levels, and this curve was found to be different from the 1 day creep curve obtained from a previous study. A long-term stress relaxation test was also performed, and it showed linear reduction of deviator stress with the logarithm of time during stress relaxation. Observations made are all aligned with the phenomenon of static fatigue and the proposed mechanism for time effects in granular materials.
Groundwater temperature measurements in a shallow coastal aquifer in Virginia Beach, Virginia, USA, suggest groundwater warming of +4.1 degree C relative to deeper geothermal gradients. Observed ...warming is related to timing and depth of influence of two potential thermal drivers-atmospheric temperature increases and urbanization. Results indicate that up to 30 % of groundwater warming at the water table can be attributed to atmospheric warming while up to 70 % of warming can be attributed to urbanization. Groundwater temperature readings to 30-m depth correlate positively with percentage of impervious cover and negatively with percentage of tree canopy cover; thus, these two land-use metrics explain up to 70 % of warming at the water table. Analytical and numerical modeling results indicate that an average vertical groundwater temperature profile for the study area, constructed from repeat measurement at 11 locations over 15 months, is consistent with the timing of land-use change over the past century in Virginia Beach. The magnitude of human-induced warming at the water table (+4.1 degree C) is twice the current seasonal temperature variation, indicating the potential for ecological impacts on wetlands and estuaries receiving groundwater discharge from shallow aquifers.Original Abstract: Des mesures de temperature des eaux souterraines dans un aquifere cotier peu profond a Virginia Beach, Virginia, Etats-Unis d'Amerique, suggerent un rechauffement des eaux souterraines de+4.1 degree C par rapport aux gradients geothermiques plus profonds. Le rechauffement observe est associe au timing et a la profondeur d'influence de deux parametres potentiels thermiques, a savoir l'augmentation de la temperature atmospherique et l'urbanisation. Les resultats indiquent que jusqu'a 30 % du rechauffement des eaux souterraines au niveau de la surface de la nappe peut etre attribue au rechauffement atmospherique alors que 70 % du rechauffement peut etre attribue a l'urbanisation. Les releves de temperature des eaux souterraines a 30 metres de profondeur sont correles positivement avec le pourcentage de la couverture impermeabilisee et negativement avec le pourcentage du couvert forestier; ainsi, ces deux metriques d'occupation du sol expliquent jusqu'a 70 % du rechauffement au niveau de la surface de la nappe phreatique. Les resultats de modelisation analytique et numerique indiquent que le profil vertical de la temperature moyenne des eaux souterraines pour la zone d'etude, construit a partir de mesures repetees en 11 points sur une periode de 15 mois, est compatible avec le timing du changement de l'occupation du sol au cours du dernier siecle a Virginia Beach. L'ampleur du rechauffement induit par l'activite humaine, de l'eau souterraine au niveau de la surface de la nappe phreatique (+4.1 degree C) est le double de la variation saisonniere actuelle de la temperature, indiquant les potentiels impacts ecologiques sur les zones humides et les estuaires alimentes par les eaux souterraines des aquiferes peu profonds.
Suprak, DN, Dawes, J, and Stephenson, MD. The effect of position on the percentage of body mass supported during traditional and modified push-up variants. J Strength Cond Res 25(2)497-503, 2011-The ...push-up is a popular upper-extremity weight-bearing exercise. However, limited information is available regarding its effectiveness. Much of the past research has focused on muscle activation levels, whereas very little has examined the forces encountered during push-up variants. The purpose of the present study was to examine the effect of position within the range of motion on the percentage of body mass (BM) supported by the upper extremities during the traditional and modified (knees-down) push-up. Twenty-eight highly strength-trained male subjects were positioned with their hands on a force platform in 4 static positions, consisting of the up and down position in both the traditional and modified push-up exercise. The performance measures included the average vertical ground reaction force (GRF), expressed as a percentage of BM, supported in each of the 4 static positions and the percentage of change between the up and down positions in each push-up exercise. In both the traditional and modified push-ups, subjects supported less weight in the up vs. the down position. The percentage change in % BM from the up to the down position was greater in the modified push-up variant. The pattern of resistances to the push-up exercises observed in this study may be a result of differing moment arms between the support surface contact point (knees or feet) and the hands. These results may be useful in prescribing programs for strengthening and/or rehabilitation for both the prime movers and stabilizers of the upper extremity. Further, range of motion may need to be altered to accommodate strength differences in beginners and clients rehabilitating from injury.
We measured black carbon (BC) in ultrafiltered, high-molecular weight dissolved organic matter (UDOM) in surface waters of Delaware Bay, Chesapeake Bay, and the adjacent Atlantic Ocean (U.S.A.) to ...investigate the importance of riverine and estuarine dissolved organic matter (DOM) as a source of BC to the ocean. BC was 5-72% of UDOM-C (27 ± 17%), which corresponds to 8.9 ± 6.5% of dissolved organic carbon (DOC), with higher values in the heavily urbanized midbay region of the Delaware Estuary and lower yields in the river and coastal ocean. The spatial and seasonal distributions of BC along the salinity gradient of Delaware Bay suggest that the elevated levels of BC in surface water UDOM originate from localized sources, possibly from atmospheric deposition or release from resuspended sediments. BC in UDOM made up 4-7% of the DOC in the coastal Atlantic Ocean, revealing that river-estuary systems are important exporters of colloidal BC to the ocean. The annual flux of BC from Delaware Bay UDOM to the Atlantic Ocean was estimated at 2.4 × 1010 g BC yr-1, supporting the hypothesis that the DOC pool is an important contributor of BC to the ocean.
Beach and nearshore morphology, defined primarily by slope and sandbar development, is very dynamic and is largely controlled by waves, currents and regional sediment characteristics. Results ...presented here challenge this long-established concept and suggest that underlying, framework geology may also exert a first-order control on nearshore morphology by influencing the stability and/or persistent re-establishment of large-scale sandbar morphology and position as well as surface sediment characteristics. Repeated sub-bottom chirp and swath bathymetry surveys of the nearshore (2–10 m depths) covering over 56 km of the North Carolina Outer Banks and Southeastern Virginia indicate the following: (1) development of shore-oblique sandbars adjacent to large gravel outcrops that are surface exposures of the underlying geologic strata, (2) identical re-development or sustained maintenance of large-scale sandbar morphology and position before and after very energetic conditions, (3) vertical and horizontal heterogeneity of lithology and grain-size and a minimum volume of sand, ranging from 0 to 1.5 m thick, and (4) close spatial alignment between the location of outcrops/shore-oblique bars and shoreline erosional hotspots. A hypothesis is proposed from these findings that links framework geology to bar morphodynamics and sorted bedforms and, ultimately, erosional hotspots. Sediment transport and shoreline evolution models based solely on waves and currents and an assumption of unlimited and uniform sediment may be inadequate in similar heterogeneous, sand-limited regions.
This project addresses the development of the ReIGNITE Free Will Baptist Church in Virginia Beach. This dissertation seeks to address the question, “When planting a new multi-ethnic church. In what ...forms can culture and composition be completely reflected?” The absence of representative leadership is evident within many multi-ethnic and homogenous churches. Culturally, America will look different in the future. Ethnic change is already taking place. Specifically, this project will support planting multiethnicity by implementing a new diverse leadership board.Sharing God’s love encourages the confidence of those on the fringe. To answer the nagging question, however, as to whether the church is for everyone? Biblical reconciliation is the key. Galatians 3:28 says, “There is neither Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus.” Various other literature complements inclusion and local efforts to establish a visual display of love within the local Church. Scripture notes that Jesus also gave a significant command to his disciples as a way forward. This command came with follow up instructions to combat against the religious systems and ill societal norms.Scripture notes Jesus said in John 13:34-35, “A new commandment I give to you, that you love one another: just as I have loved you, you also are to love one another.” This project will build on the vision of Jesus to use love as a reconciliation tool as the eschatological portrait of heaven.
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