Fig 3 - uploaded by Melissa Moulton
Content may be subject to copyright.
![(Color) Energy density (normalized by the total variance) of cross-shore velocity observed near the center of the hole (colored curves are different times) and 80 m offshore (black curve) versus frequency [the times (hours (EST) on September 19, 2005, are listed]](profile/Melissa-Moulton/publication/265570428/figure/fig3/AS:671512344408078@1537112427716/Color-Energy-density-normalized-by-the-total-variance-of-cross-shore-velocity.png)
(Color) Energy density (normalized by the total variance) of cross-shore velocity observed near the center of the hole (colored curves are different times) and 80 m offshore (black curve) versus frequency [the times (hours (EST) on September 19, 2005, are listed]
Source publication
Water oscillations observed in a 10-m-diameter, 2-m-deep hole excavated on the foreshore just above the low-tide line on an ocean beach were consistent with theory. When swashes first filled the initially circular hole on the rising tide, the dominant mode observed in the cross-shore velocity was consistent with a zero-order Bessel function solutio...
Contexts in source publication
Context 1
... density spectra from the 512-s long time series of cross- shore velocity observed in the hole have peaks that do not always coincide with the frequency of the incident wind waves (Fig. 3). Specifically, although between 1700 and 1900 hrs. the incident waves (observed in 1.2 m depth, 80 m offshore of the hole) were dominated by f ¼ 0:10 Hz swell (black curve, Fig. 3), the motions inside the hole had spectral peaks that ranged from near f ¼ 0:14 Hz (red curve, Fig. 3) when water first entered the hole [1700 hrs., Fig. ...
Context 2
... from the 512-s long time series of cross- shore velocity observed in the hole have peaks that do not always coincide with the frequency of the incident wind waves (Fig. 3). Specifically, although between 1700 and 1900 hrs. the incident waves (observed in 1.2 m depth, 80 m offshore of the hole) were dominated by f ¼ 0:10 Hz swell (black curve, Fig. 3), the motions inside the hole had spectral peaks that ranged from near f ¼ 0:14 Hz (red curve, Fig. 3) when water first entered the hole [1700 hrs., Fig. 1(a)] to f ¼ 0:16 Hz (green curve, Fig. 3) to f ¼ 0:18 Hz (blue curve, Fig. 3), to f ¼ 0:10 (pink curve, Fig. 3) as the hole evolved (Fig. 1). Although the confidence limits on the ...
Context 3
... always coincide with the frequency of the incident wind waves (Fig. 3). Specifically, although between 1700 and 1900 hrs. the incident waves (observed in 1.2 m depth, 80 m offshore of the hole) were dominated by f ¼ 0:10 Hz swell (black curve, Fig. 3), the motions inside the hole had spectral peaks that ranged from near f ¼ 0:14 Hz (red curve, Fig. 3) when water first entered the hole [1700 hrs., Fig. 1(a)] to f ¼ 0:16 Hz (green curve, Fig. 3) to f ¼ 0:18 Hz (blue curve, Fig. 3), to f ¼ 0:10 (pink curve, Fig. 3) as the hole evolved (Fig. 1). Although the confidence limits on the spectral estimates with 20 degrees of freedom (obtained by merging 10 neighboring frequencies in ...
Context 4
... between 1700 and 1900 hrs. the incident waves (observed in 1.2 m depth, 80 m offshore of the hole) were dominated by f ¼ 0:10 Hz swell (black curve, Fig. 3), the motions inside the hole had spectral peaks that ranged from near f ¼ 0:14 Hz (red curve, Fig. 3) when water first entered the hole [1700 hrs., Fig. 1(a)] to f ¼ 0:16 Hz (green curve, Fig. 3) to f ¼ 0:18 Hz (blue curve, Fig. 3), to f ¼ 0:10 (pink curve, Fig. 3) as the hole evolved (Fig. 1). Although the confidence limits on the spectral estimates with 20 degrees of freedom (obtained by merging 10 neighboring frequencies in periodogram estimates of the spec- tra, resulting in a frequency resolution of approximately 0.02 Hz) ...
Context 5
... waves (observed in 1.2 m depth, 80 m offshore of the hole) were dominated by f ¼ 0:10 Hz swell (black curve, Fig. 3), the motions inside the hole had spectral peaks that ranged from near f ¼ 0:14 Hz (red curve, Fig. 3) when water first entered the hole [1700 hrs., Fig. 1(a)] to f ¼ 0:16 Hz (green curve, Fig. 3) to f ¼ 0:18 Hz (blue curve, Fig. 3), to f ¼ 0:10 (pink curve, Fig. 3) as the hole evolved (Fig. 1). Although the confidence limits on the spectral estimates with 20 degrees of freedom (obtained by merging 10 neighboring frequencies in periodogram estimates of the spec- tra, resulting in a frequency resolution of approximately 0.02 Hz) were large (90% bars in Fig. 3), ...
Context 6
... 80 m offshore of the hole) were dominated by f ¼ 0:10 Hz swell (black curve, Fig. 3), the motions inside the hole had spectral peaks that ranged from near f ¼ 0:14 Hz (red curve, Fig. 3) when water first entered the hole [1700 hrs., Fig. 1(a)] to f ¼ 0:16 Hz (green curve, Fig. 3) to f ¼ 0:18 Hz (blue curve, Fig. 3), to f ¼ 0:10 (pink curve, Fig. 3) as the hole evolved (Fig. 1). Although the confidence limits on the spectral estimates with 20 degrees of freedom (obtained by merging 10 neighboring frequencies in periodogram estimates of the spec- tra, resulting in a frequency resolution of approximately 0.02 Hz) were large (90% bars in Fig. 3), the peaks are statistically signifi- ...
Context 7
... Hz (blue curve, Fig. 3), to f ¼ 0:10 (pink curve, Fig. 3) as the hole evolved (Fig. 1). Although the confidence limits on the spectral estimates with 20 degrees of freedom (obtained by merging 10 neighboring frequencies in periodogram estimates of the spec- tra, resulting in a frequency resolution of approximately 0.02 Hz) were large (90% bars in Fig. 3), the peaks are statistically signifi- cant. Alongshore velocities have spectral peaks at frequencies similar to those for cross-shore velocities, as well as at other frequencies. However, the alongshore velocities were about an order of magnitude smaller than the cross-shore velocities, resulting in less confidence in the spectral ...
Context 8
... with a lowest-order mode, with water sloshing back and forth in the cross-shore direction. As the tide rose and the sediment was transported by swash, the diameter of the wetted circle decreased [Fig. 2(c)], the water depth inside the hole changed only slightly [Fig. 2(c)], and the observed and pre- dicted resonant frequencies increased (Figs. 3 and 4, time ¼ 1700-1824 hrs.). When the hole was primarily a closed circle (1700 < time < 1800 hrs., Figs. 1 and 2), there was one spectral peak (Figs. 3 and 4). As the hole shape evolved toward a semicircle, the observations were consistent with an increase in the relative amplitude of the quarter-wavelength mode for an open semicircle (see ...
Context 9
... swash, the diameter of the wetted circle decreased [Fig. 2(c)], the water depth inside the hole changed only slightly [Fig. 2(c)], and the observed and pre- dicted resonant frequencies increased (Figs. 3 and 4, time ¼ 1700-1824 hrs.). When the hole was primarily a closed circle (1700 < time < 1800 hrs., Figs. 1 and 2), there was one spectral peak (Figs. 3 and 4). As the hole shape evolved toward a semicircle, the observations were consistent with an increase in the relative amplitude of the quarter-wavelength mode for an open semicircle (see Fig. 4, where the lower solid curve is the predicted frequency for the lowest-order resonant mode for an open semicircle given the observed changing ...
Context 10
... the observed spectral peaks for the open semicircle were consistent with theory (f ≈ 0:09 Hz, Fig. 4), they also were close to the frequency of the incident waves (f ≈ 0:10 Hz, Fig. 3 black curve; Fig. 4 dotted line). If the oscillations observed near the open edge of the semicircle were owing to progressive inci- dent waves, there would be a spectral peak in both cross-shore velocity and sea-surface elevation (or, similarly, vertical velocity) fluctuations. In contrast, the observations were consistent with a ...
Similar publications
In this paper, a new distribution is introduced by taking the product of the probability density functions of Bessel distribution of first kind and gamma distribution. Some distributional properties and a characterization of the proposed product distribution are provided. The percentile points for some selected values of parameters are also present...
In a recent paper, Veestraeten [19] obtained the inverse of Laplace
transforms that contain products of two parabolic cylinder functions. These
inverse Laplace transforms were derived by exploiting the link between the
transition density and distribution of the Ornstein-Uhlenbeck process and the
parabolic cylinder function. This paper uses these re...
A new representation of solutions to the equation $-y"+q(x)y=\omega^2 y$ is obtained. For every $x$ the solution is represented as a Neumann series of Bessel functions depending on the spectral parameter $\omega$. Due to the fact that the representation is obtained using the corresponding transmutation operator, a partial sum of the series approxim...
![Fig. 5 Comparisons of different kinds of Re[ ˆ R ab ] with J0(k0r)e...](profile/Laiyu-Lu/publication/312643569/figure/fig5/AS:670497373159437@1536870439737/Comparisons-of-different-kinds-of-Re-R-ab-with-J0k0re-aor-and-J0k0r_Q320.jpg)
Traditionally, for the tomography based on the correlation of seismic noise, primarily the phase information of ambient noise correlation function (NCF) is used to extract the seismic velocity and anisotropy of the earth by travel time inversion. Researchers recently utilize the amplitude of NCF to extract the earth's attenuation. According to the...
Citations
... Wang et al. (1999) reported values of 0.04 to 0.54, whereas Martin-Grandes et al. (2009) calibrated a one-line model finding that K=0.06-0.10. Recent studies have focused on investigating the morphodynamic responses to seafloor artificial perturbations (e.g., excavated holes and channels) in the nearshore (Elgar et al. 2012;Moulton et al. 2014, Moulton et al. 2017. Moulton et al. (2014) investigated the mechanisms controlling the infill of large excavated holes in the surf zone, finding that downslope gravity-driven bedload transport was important in morphological evolution for bathymetric features with large slopes. ...
The work presents the results of a field and numerical study aimed to investigate the resistance and resilience, associated to an artificial shoreline perturbation, on a sandy beach. A temporary groin was deployed on a micro-tidal sea-breeze dominated beach to induce a shoreline perturbation. Wave conditions during the field experiment were highly correlated with sea breeze wind events, inducing a persistent alongshore sediment transport. A new one-line numerical model of beach evolution was calibrated and verified with the field surveys, reproducing both the sediment impoundment and subsequent beach recovery after the groin removal. Thus, the numerical model was able to simulate the mechanisms controlling the growth and decay caused by an artificial perturbation.
The understanding of the beach capability to resist and recover from a disturbance is of paramount importance in coastal engineering. However, few efforts have been devoted to quantifying beach resilience. The present work aims to investigate the shoreline resistance and resilience, associated to a transient disturbance, on a sandy beach. A temporary groin was deployed for 24 h on a micro-tidal sea-breeze dominated beach to induce a shoreline perturbation. Morphological changes were measured by means of beach surveys to estimate the beach perturbation and the further beach recovery after structure removal. An Empirical Orthogonal Function (EOF) analysis of the shoreline position suggests that the first EOF mode describes the spatial-temporal evolution of the shoreline owing to the groin deployment/removal. A new one-line numerical model of beach evolution is calibrated with the field surveys, reproducing both the sediment impoundment and subsequent beach recovery after the structure removal. Thus, a parametric numerical study is conducted to quantify resistance and resilience. Numerical results suggest that beach resistance associated to the presence of a structure decreases with increasing alongshore sediment transport potential, whereas resilience after structure removal is positively correlated with the alongshore diffusivity.
