Bedding structures in Indian tsunami deposits that provide clues to the dynamics of tsunami inundation

The 2004 Indian Ocean tsunami deposited an extensive sandsheet on the coastal plain of SE India. At particular sites, the sedimentary bedding in the sandsheet provides evidence of variable energy conditions and flow during inundation of the coast. Trenching of the deposits at sites where only unidir...

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Main Authors: Switzer, Adam D., Srinivasalu, S., Thangadurai, N., Ram Mohan, V.
Format: Article
Language:English
Published: 2013
Online Access:https://hdl.handle.net/10356/100374
http://hdl.handle.net/10220/16282
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1003742020-03-07T12:45:26Z Bedding structures in Indian tsunami deposits that provide clues to the dynamics of tsunami inundation Switzer, Adam D. Srinivasalu, S. Thangadurai, N. Ram Mohan, V. The 2004 Indian Ocean tsunami deposited an extensive sandsheet on the coastal plain of SE India. At particular sites, the sedimentary bedding in the sandsheet provides evidence of variable energy conditions and flow during inundation of the coast. Trenching of the deposits at sites where only unidirectional flow was observed allowed the investigation of changes in hydrodynamics recorded in bedding structures without the added complexity of return flows and reworking. A high-velocity initial surge is recorded as upper flow regime (UFR) plane bedding. Following the initial high flow a period of falling flow velocity and quiescence occurs where sediments settle out of suspension, often resulting in a reverse graded bed that transitions to a graded (fining-up) bed. As water levels begin to decline after maximum inundation sheet flow caused the formation of inversely graded (coarsening-up) beds or a return to UFR conditions. At one site the final stages of tsunami inundation is recorded as small channels that have an erosional base and are filled with graded sediments that exhibit complex patterns of sedimentation. Pits excavated in areas of unidirectional flow allow the development of a sedimentary model for tsunami sediment dynamics across flat topography under unidirectional flow conditions. 2013-10-04T07:18:40Z 2019-12-06T20:21:24Z 2013-10-04T07:18:40Z 2019-12-06T20:21:24Z 2012 2012 Journal Article Switzer, A. D., Srinivasalu, S., Thangadurai, N., & Ram Mohan, V. (2012). Bedding structures in Indian tsunami deposits that provide clues to the dynamics of tsunami inundation. Geological Society, London, Special Publications, 361, 61-77. https://hdl.handle.net/10356/100374 http://hdl.handle.net/10220/16282 10.1144/SP361.6 en Geological society, London, special publications
institution Nanyang Technological University
building NTU Library
country Singapore
collection DR-NTU
language English
description The 2004 Indian Ocean tsunami deposited an extensive sandsheet on the coastal plain of SE India. At particular sites, the sedimentary bedding in the sandsheet provides evidence of variable energy conditions and flow during inundation of the coast. Trenching of the deposits at sites where only unidirectional flow was observed allowed the investigation of changes in hydrodynamics recorded in bedding structures without the added complexity of return flows and reworking. A high-velocity initial surge is recorded as upper flow regime (UFR) plane bedding. Following the initial high flow a period of falling flow velocity and quiescence occurs where sediments settle out of suspension, often resulting in a reverse graded bed that transitions to a graded (fining-up) bed. As water levels begin to decline after maximum inundation sheet flow caused the formation of inversely graded (coarsening-up) beds or a return to UFR conditions. At one site the final stages of tsunami inundation is recorded as small channels that have an erosional base and are filled with graded sediments that exhibit complex patterns of sedimentation. Pits excavated in areas of unidirectional flow allow the development of a sedimentary model for tsunami sediment dynamics across flat topography under unidirectional flow conditions.
format Article
author Switzer, Adam D.
Srinivasalu, S.
Thangadurai, N.
Ram Mohan, V.
spellingShingle Switzer, Adam D.
Srinivasalu, S.
Thangadurai, N.
Ram Mohan, V.
Bedding structures in Indian tsunami deposits that provide clues to the dynamics of tsunami inundation
author_facet Switzer, Adam D.
Srinivasalu, S.
Thangadurai, N.
Ram Mohan, V.
author_sort Switzer, Adam D.
title Bedding structures in Indian tsunami deposits that provide clues to the dynamics of tsunami inundation
title_short Bedding structures in Indian tsunami deposits that provide clues to the dynamics of tsunami inundation
title_full Bedding structures in Indian tsunami deposits that provide clues to the dynamics of tsunami inundation
title_fullStr Bedding structures in Indian tsunami deposits that provide clues to the dynamics of tsunami inundation
title_full_unstemmed Bedding structures in Indian tsunami deposits that provide clues to the dynamics of tsunami inundation
title_sort bedding structures in indian tsunami deposits that provide clues to the dynamics of tsunami inundation
publishDate 2013
url https://hdl.handle.net/10356/100374
http://hdl.handle.net/10220/16282
_version_ 1681036815239217152