Saw-tooth pattern of North Atlantic current speed during Dansgaard-Oeschger cycles revealed by the magnetic grain size of Reykjanes Ridge sediments at 59 degrees N
(2003) In Paleoceanography 18(2).- Abstract
- Detailed mineral (rock) magnetic measurements, including high-resolution magnetic hysteresis loops, were carried out on three sediment cores recovered from the Reykjanes Ridge in the North Atlantic. Supported by physical grain-size analyses, titanomagnetite grain-size variations form a proxy of the speed of near-bottom currents and reveal a cyclic ""saw-tooth'' pattern between Dansgaard-Oeschger cycles 8 and 5. The magnetic grain-size data suggest that these Dansgaard-Oeschger cycles were characterized by gradual intensification of the near-bottom current speed, while other paleoceanographic proxies indicate escalating iceberg discharge and declining sea surface temperatures. These observations are contrary to the frequently assumed and... (More)
- Detailed mineral (rock) magnetic measurements, including high-resolution magnetic hysteresis loops, were carried out on three sediment cores recovered from the Reykjanes Ridge in the North Atlantic. Supported by physical grain-size analyses, titanomagnetite grain-size variations form a proxy of the speed of near-bottom currents and reveal a cyclic ""saw-tooth'' pattern between Dansgaard-Oeschger cycles 8 and 5. The magnetic grain-size data suggest that these Dansgaard-Oeschger cycles were characterized by gradual intensification of the near-bottom current speed, while other paleoceanographic proxies indicate escalating iceberg discharge and declining sea surface temperatures. These observations are contrary to the frequently assumed and strictly applied positive relationship between high-latitude warmth and North Atlantic Deep Water formation. Within the confines of temporal control, however, it would appear that peaks in iceberg discharge and slow near-bottom current speeds were synchronous. The magnetic hysteresis data also demonstrate that magnetic concentration parameters, such as magnetic susceptibility, do not necessarily provide direct evidence of paleocirculation. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/312436
- author
- Snowball, Ian LU and Moros, M
- organization
- publishing date
- 2003
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- circulation, thermohaline, current speed, North Atlantic, magnetic grain-size, Dansgaard-Oeschger cycles
- in
- Paleoceanography
- volume
- 18
- issue
- 2
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- wos:000182595700001
- scopus:0142122148
- ISSN
- 0883-8305
- DOI
- 10.1029/2001PA000732
- language
- English
- LU publication?
- yes
- id
- 317d849d-9a25-4c57-897e-8e17ec2aa09e (old id 312436)
- date added to LUP
- 2016-04-01 11:51:22
- date last changed
- 2022-04-28 21:01:14
@article{317d849d-9a25-4c57-897e-8e17ec2aa09e,
abstract = {{Detailed mineral (rock) magnetic measurements, including high-resolution magnetic hysteresis loops, were carried out on three sediment cores recovered from the Reykjanes Ridge in the North Atlantic. Supported by physical grain-size analyses, titanomagnetite grain-size variations form a proxy of the speed of near-bottom currents and reveal a cyclic ""saw-tooth'' pattern between Dansgaard-Oeschger cycles 8 and 5. The magnetic grain-size data suggest that these Dansgaard-Oeschger cycles were characterized by gradual intensification of the near-bottom current speed, while other paleoceanographic proxies indicate escalating iceberg discharge and declining sea surface temperatures. These observations are contrary to the frequently assumed and strictly applied positive relationship between high-latitude warmth and North Atlantic Deep Water formation. Within the confines of temporal control, however, it would appear that peaks in iceberg discharge and slow near-bottom current speeds were synchronous. The magnetic hysteresis data also demonstrate that magnetic concentration parameters, such as magnetic susceptibility, do not necessarily provide direct evidence of paleocirculation.}},
author = {{Snowball, Ian and Moros, M}},
issn = {{0883-8305}},
keywords = {{circulation; thermohaline; current speed; North Atlantic; magnetic grain-size; Dansgaard-Oeschger cycles}},
language = {{eng}},
number = {{2}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Paleoceanography}},
title = {{Saw-tooth pattern of North Atlantic current speed during Dansgaard-Oeschger cycles revealed by the magnetic grain size of Reykjanes Ridge sediments at 59 degrees N}},
url = {{http://dx.doi.org/10.1029/2001PA000732}},
doi = {{10.1029/2001PA000732}},
volume = {{18}},
year = {{2003}},
}