NDLI: Ripples in intertidal mud—a conceptual explanation

Content Provider	Springer Nature Link
Author	Chang, Tae Soo Flemming, Burghard W.
Copyright Year	2013
Abstract	On protected mudflats and along sheltered tidal channel margins, wave- and current-generated ripples are frequently observed on surficial and subsurface mud beds, although such bedforms are generally not thought to occur in cohesive sediments. In this paper, examples of such ripple marks in the German Wadden Sea (back-barrier tidal flats of Spiekeroog island) and also along the west coast of Korea (Baeksu tidal flats) are documented and analyzed. The mud ripples are 5–8 cm in spacing and 0.3–0.8 cm in height, and are composed of slightly sandy to virtually pure mud (80–98% mud content). For the Spiekeroog study area, a comparison of in situ particle-size measurements of suspended matter and of dispersed mud collected from the ripples shows that the former consists of low-density flocs which are considerably larger than the constituent grains of the latter. To assess local wave effects, near-bed orbital velocities and orbital diameters were calculated on the basis of standard wave theory using estimated wave parameters at the time of the study (June 2004) as well as wave data recorded nearby within the back-barrier tidal basin. The relationships between grain size, morphometric ripple parameters, and the near-bed orbital diameter show the wave-generated mud ripples to be of the orbital post-vortex type. It is demonstrated that only short-period shoaling (intermediate water depth) waves with periods of 1.5–2.5 s and heights of 0.1–0.5 m are able to generate and maintain such ripples. Corresponding near-bed orbital velocities range from 8–32 cm s–1 and near-bed orbital diameters from 6.25–10 cm. It can be anticipated that increased current shear and turbulence associated with higher and longer waves prevent ripple formation due to the resuspension of settled mud, and the breakdown of suspended flocs and aggregates into smaller particles which then tend to remain in suspension. The most plausible explanation for the formation of the mud ripples is that mud flocs and aggregates deposited from suspension around high-water slack tide under moderate weather conditions initially respond as single (non-cohesive) particles which are hydraulically equivalent to ambient very fine sands. During exposure at low tide, gradual loss of water transforms the rippled mud into increasingly more cohesive mud drapes which are more resistant to erosion. Unless destroyed during high-energy events, the mud ripples may remain intact long enough to become buried and thereby preserved. Indeed, occasional but persistent observations of ripples in sub-Recent to ancient mudrocks document their preservation potential.
Starting Page	449
Ending Page	461
Page Count	13
File Format	PDF
ISSN	02760460
Journal	Geo-Marine Letters
Volume Number	33
Issue Number	6
e-ISSN	14321157
Language	English
Publisher	Springer Berlin Heidelberg
Publisher Date	2013-08-04
Publisher Place	Berlin, Heidelberg
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	Geology
Content Type	Text
Resource Type	Article
Subject	Environmental Science Geotechnical Engineering and Engineering Geology Oceanography

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Mud and fluid migration in active mud volcanoes in Azerbaijan

Factors controlling mud accumulation in the Heuksan mud belt off southwestern Korea

Mud volcanoes—a significant source of atmospheric methane

Clay mineral distribution and provenance in the Heuksan mud belt, Yellow Sea

Mud depocenters on continental shelves—appearance, initiation times, and growth dynamics

Mud volcanoes and gas vents in the Okhotsk Sea area

A snapshot of suspended sediment and fluid mud occurrence in a mixed-energy embayment, Tijucas Bay, Brazil

The Shandong mud wedge and post-glacial sediment accumulation in the Yellow Sea

Gas hydrate accumulation at the Håkon Mosby Mud Volcano

Ripples in intertidal mud—a conceptual explanation

Similar Documents

Mud and fluid migration in active mud volcanoes in Azerbaijan

Factors controlling mud accumulation in the Heuksan mud belt off southwestern Korea

Mud volcanoes—a significant source of atmospheric methane

Clay mineral distribution and provenance in the Heuksan mud belt, Yellow Sea

Mud depocenters on continental shelves—appearance, initiation times, and growth dynamics

Mud volcanoes and gas vents in the Okhotsk Sea area

A snapshot of suspended sediment and fluid mud occurrence in a mixed-energy embayment, Tijucas Bay, Brazil

The Shandong mud wedge and post-glacial sediment accumulation in the Yellow Sea

Gas hydrate accumulation at the Håkon Mosby Mud Volcano

Ripples in intertidal mud—a conceptual explanation