Dune systems in relation to rising seas
Beaches and associated dunes are constituted of unconsolidated materials, such as sand, and thus are low-strength land forms less robust than rocky cliffs (van der Meulen et al. 1991). It is estimated that 70% of sand-based coastlines in the world are presently subject to erosion (Bird 1985; Wind an...
Main Authors: | , |
---|---|
Format: | Book Part |
Language: | unknown |
Published: |
Oxford University Press
2009
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1093/oso/9780198570356.003.0018 |
id |
croxfordunivpr:10.1093/oso/9780198570356.003.0018 |
---|---|
record_format |
openpolar |
spelling |
croxfordunivpr:10.1093/oso/9780198570356.003.0018 2023-05-15T17:36:30+02:00 Dune systems in relation to rising seas Maun, Anwar Fahselt, Dianne 2009 http://dx.doi.org/10.1093/oso/9780198570356.003.0018 unknown Oxford University Press The Biology of Coastal Sand Dunes book-chapter 2009 croxfordunivpr https://doi.org/10.1093/oso/9780198570356.003.0018 2022-08-05T10:29:53Z Beaches and associated dunes are constituted of unconsolidated materials, such as sand, and thus are low-strength land forms less robust than rocky cliffs (van der Meulen et al. 1991). It is estimated that 70% of sand-based coastlines in the world are presently subject to erosion (Bird 1985; Wind and Peerbolte 1993). However, natural dune systems are inclined to adjust after stress without permanent damage (Brown and McLachlin 2002), and when stabilized by plant cover they offer a first line of coastal defence against assault from wave action (Wind and Peerbolte 1993; Broadus 1993; De Ronde 1993). Natural self-sustaining dune systems interact with the sea and closely reflect changes in sea levels. At any given time no single sea level characterizes all oceans, that is, the resting position of the ocean surface, or geoid, is not uniformly elevated over the earth. Eustatic sea levels, free of influence from tides, waves and storms, thus vary from place to place as well as over time. Satellite altimetry, which permits more accurate as well as more numerous observations than older tide-gage methods of measuring sea levels, shows that the ocean is actually a spheroid modified by depressions and elevations. For example, in parts of the Indian Ocean sea levels are as much as 70 m lower than the global mean and in the North Atlantic 80 m higher (Carter 1988). Climate is governed by long-term periodic variations in the earth’s orbit that effect changes in solar radiation and, consequently, also in sea levels (Bartlein and Prentice 1989; Woodroffe 2002). As a result, ice ages repeatedly alternate with periods of interglacial warming in which ice masses contract and sea levels increase. Most of the time that has passed since the Cambrian period—approximately 500 million years—sea levels, although fluctuating on several timescales, have been higher than they are today. Because of the difficulties in documenting conditions so far in the distant past estimates of these sea levels vary considerably, but those shown in Fig. ... Book Part North Atlantic Oxford University Press (via Crossref) Indian Ronde ENVELOPE(141.258,141.258,-66.793,-66.793) |
institution |
Open Polar |
collection |
Oxford University Press (via Crossref) |
op_collection_id |
croxfordunivpr |
language |
unknown |
description |
Beaches and associated dunes are constituted of unconsolidated materials, such as sand, and thus are low-strength land forms less robust than rocky cliffs (van der Meulen et al. 1991). It is estimated that 70% of sand-based coastlines in the world are presently subject to erosion (Bird 1985; Wind and Peerbolte 1993). However, natural dune systems are inclined to adjust after stress without permanent damage (Brown and McLachlin 2002), and when stabilized by plant cover they offer a first line of coastal defence against assault from wave action (Wind and Peerbolte 1993; Broadus 1993; De Ronde 1993). Natural self-sustaining dune systems interact with the sea and closely reflect changes in sea levels. At any given time no single sea level characterizes all oceans, that is, the resting position of the ocean surface, or geoid, is not uniformly elevated over the earth. Eustatic sea levels, free of influence from tides, waves and storms, thus vary from place to place as well as over time. Satellite altimetry, which permits more accurate as well as more numerous observations than older tide-gage methods of measuring sea levels, shows that the ocean is actually a spheroid modified by depressions and elevations. For example, in parts of the Indian Ocean sea levels are as much as 70 m lower than the global mean and in the North Atlantic 80 m higher (Carter 1988). Climate is governed by long-term periodic variations in the earth’s orbit that effect changes in solar radiation and, consequently, also in sea levels (Bartlein and Prentice 1989; Woodroffe 2002). As a result, ice ages repeatedly alternate with periods of interglacial warming in which ice masses contract and sea levels increase. Most of the time that has passed since the Cambrian period—approximately 500 million years—sea levels, although fluctuating on several timescales, have been higher than they are today. Because of the difficulties in documenting conditions so far in the distant past estimates of these sea levels vary considerably, but those shown in Fig. ... |
format |
Book Part |
author |
Maun, Anwar Fahselt, Dianne |
spellingShingle |
Maun, Anwar Fahselt, Dianne Dune systems in relation to rising seas |
author_facet |
Maun, Anwar Fahselt, Dianne |
author_sort |
Maun, Anwar |
title |
Dune systems in relation to rising seas |
title_short |
Dune systems in relation to rising seas |
title_full |
Dune systems in relation to rising seas |
title_fullStr |
Dune systems in relation to rising seas |
title_full_unstemmed |
Dune systems in relation to rising seas |
title_sort |
dune systems in relation to rising seas |
publisher |
Oxford University Press |
publishDate |
2009 |
url |
http://dx.doi.org/10.1093/oso/9780198570356.003.0018 |
long_lat |
ENVELOPE(141.258,141.258,-66.793,-66.793) |
geographic |
Indian Ronde |
geographic_facet |
Indian Ronde |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
The Biology of Coastal Sand Dunes |
op_doi |
https://doi.org/10.1093/oso/9780198570356.003.0018 |
_version_ |
1766136009462906880 |