Next Article in Journal
Improvement of Mooring Configurations in Geraldton Harbour
Next Article in Special Issue
Natural and Human-Induced Dynamics on Big Hickory Island, Florida
Previous Article in Journal
Geological and Sedimentological Evidence of a Large Tsunami Occurring ~1100 Year BP from a Small Coastal Lake along the Bay of La Paz in Baja California Sur, Mexico
Previous Article in Special Issue
Wave and Hydrodynamic Modeling for Engineering Design of Jetties at Tangier Island in Chesapeake Bay, USA
Article Menu

Export Article

Open AccessArticle
J. Mar. Sci. Eng. 2015, 3(4), 1568-1594; doi:10.3390/jmse3041568

Geometry of Wave-Formed Orbital Ripples in Coarse Sand

Department of Physical Geography, Faculty of Geosciences, Utrecht University, P.O. Box 80.115, 3508 TC Utrecht, The Netherlands
*
Author to whom correspondence should be addressed.
Academic Editor: Edward J. Anthony
Received: 3 November 2015 / Revised: 3 December 2015 / Accepted: 14 December 2015 / Published: 21 December 2015
(This article belongs to the Special Issue Coastal Morphodynamics)
View Full-Text   |   Download PDF [6744 KB, uploaded 21 December 2015]   |  

Abstract

Using new large-scale wave-flume experiments we examine the cross-section and planform geometry of wave-formed ripples in coarse sand (median grain size D50 = 430 μm) under high-energy shoaling and plunging random waves. We find that the ripples remain orbital for the full range of encountered conditions, even for wave forcing when in finer sand the ripple length λr is known to become independent of the near-bed orbital diameter ds (anorbital ripples). The proportionality between λr and ds is not constant, but decreases from about 0.55 for ds / D50 ≈ 1400 to about 0.27 for ds / D50 ≈ 11 , 500 . Analogously, ripple height ηr increases with ds, but the constant of proportionally decreases from about 0.08 for ds / D50 ≈ 1400 to about 0.02 for ds / D50 > 8000 . In contrast to earlier observations of coarse-grained two-dimensional wave ripples under mild wave conditions, the ripple planform changes with the wave Reynolds number from quasi two-dimensional vortex ripples, through oval mounds with ripples attached from different directions, to strongly subdued hummocky-type features. Finally, we combine our data with existing mild-wave coarse-grain ripple data to develop new equilibrium predictors for ripple length, height and steepness suitable for a wide range of wave conditions and a D50 larger than about 300 μm. View Full-Text
Keywords: orbital ripples; hummocks; flume experiment; empirical prediction orbital ripples; hummocks; flume experiment; empirical prediction
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Ruessink, G.; Brinkkemper, J.A.; Kleinhans, M.G. Geometry of Wave-Formed Orbital Ripples in Coarse Sand. J. Mar. Sci. Eng. 2015, 3, 1568-1594.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
J. Mar. Sci. Eng. EISSN 2077-1312 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top