Relative sea level and coastal environments in arctic Alaska during Marine Isotope Stage 5
Marine Isotope Stage (MIS) 5 was characterized by marked fluctuations in climate, the warmest being MIS 5e (124-119 ka) when relative sea level (RSL) stood 2-10 m higher than today along many coastlines. In northern Alaska, marine deposits now 5-10 m above modern sea level are assigned to this time...
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ftawi:oai:epic.awi.de:39331 2024-09-15T17:51:07+00:00 Relative sea level and coastal environments in arctic Alaska during Marine Isotope Stage 5 Farquharson, Louise M. Mann, Daniel H. Jones, Benjamin Rittenour, Tammy Grosse, Guido Groves, Pamela 2015-12-17 https://epic.awi.de/id/eprint/39331/ https://agu.confex.com/agu/fm15/meetingapp.cgi/Paper/70816 https://hdl.handle.net/10013/epic.46514 unknown Farquharson, L. M. , Mann, D. H. , Jones, B. , Rittenour, T. , Grosse, G. orcid:0000-0001-5895-2141 and Groves, P. (2015) Relative sea level and coastal environments in arctic Alaska during Marine Isotope Stage 5 , AGU Fall Meeting, San Francisco, USA, 14 December 2015 - 18 December 2015 . hdl:10013/epic.46514 EPIC3AGU Fall Meeting, San Francisco, USA, 2015-12-14-2015-12-18 Conference notRev 2015 ftawi 2024-06-24T04:13:16Z Marine Isotope Stage (MIS) 5 was characterized by marked fluctuations in climate, the warmest being MIS 5e (124-119 ka) when relative sea level (RSL) stood 2-10 m higher than today along many coastlines. In northern Alaska, marine deposits now 5-10 m above modern sea level are assigned to this time period and termed the Pelukian transgression (PT). Complicating this interpretation is the possibility that an intra-Stage 5 ice shelf extended along the Alaskan coast, causing isostatic depression along its grounded margins, which caused RSL highs even during periods of low, global RSL. Here we use optically stimulated luminescence (OSL) to date inferred PT deposits on the Beaufort Sea coastal plain. A transition from what we interpret to be lagoonal mud to sandy tidal flat deposits lying ~ 2.75 m asl dates to 113+/-18 ka. Above this, a 5-m thick gravelly barrier beach dates to 95 +/- 20 ka. This beach contains well-preserved marine molluscs, whale vertebrae, and walrus tusks. Pleistocene-aged ice-rich eolian silt (yedoma) blanket the marine deposits and date to 57.6 +/-10.9 ka. Our interpretation of this chronostratigraphy is that RSL was several meters higher than today during MIS 5e, and lagoons or brackish lakes were prevalent. Gravel barrier beaches moved onshore as local RSL rose further after MIS 5e. The error range of the OSL age of the barrier-beach unit spans the remaining four substages of MIS 5; however, the highstand of RSL on this arctic coastline appears to occurr after the warmest part of the last interglacial and appears not to be coeval with the eustatic maximum reached at lower latitudes during MIS 5. One possibility is that RSL along the Beaufort Sea coast was affected by isostatic depression caused by an ice shelf associated with widespread, intra-Stage 5 glaciation that was out of phase with lower latitude glaciation and whose extent and timing remains enigmatic. Conference Object Arctic Beaufort Sea Ice Shelf Alaska walrus* Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
institution |
Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Marine Isotope Stage (MIS) 5 was characterized by marked fluctuations in climate, the warmest being MIS 5e (124-119 ka) when relative sea level (RSL) stood 2-10 m higher than today along many coastlines. In northern Alaska, marine deposits now 5-10 m above modern sea level are assigned to this time period and termed the Pelukian transgression (PT). Complicating this interpretation is the possibility that an intra-Stage 5 ice shelf extended along the Alaskan coast, causing isostatic depression along its grounded margins, which caused RSL highs even during periods of low, global RSL. Here we use optically stimulated luminescence (OSL) to date inferred PT deposits on the Beaufort Sea coastal plain. A transition from what we interpret to be lagoonal mud to sandy tidal flat deposits lying ~ 2.75 m asl dates to 113+/-18 ka. Above this, a 5-m thick gravelly barrier beach dates to 95 +/- 20 ka. This beach contains well-preserved marine molluscs, whale vertebrae, and walrus tusks. Pleistocene-aged ice-rich eolian silt (yedoma) blanket the marine deposits and date to 57.6 +/-10.9 ka. Our interpretation of this chronostratigraphy is that RSL was several meters higher than today during MIS 5e, and lagoons or brackish lakes were prevalent. Gravel barrier beaches moved onshore as local RSL rose further after MIS 5e. The error range of the OSL age of the barrier-beach unit spans the remaining four substages of MIS 5; however, the highstand of RSL on this arctic coastline appears to occurr after the warmest part of the last interglacial and appears not to be coeval with the eustatic maximum reached at lower latitudes during MIS 5. One possibility is that RSL along the Beaufort Sea coast was affected by isostatic depression caused by an ice shelf associated with widespread, intra-Stage 5 glaciation that was out of phase with lower latitude glaciation and whose extent and timing remains enigmatic. |
format |
Conference Object |
author |
Farquharson, Louise M. Mann, Daniel H. Jones, Benjamin Rittenour, Tammy Grosse, Guido Groves, Pamela |
spellingShingle |
Farquharson, Louise M. Mann, Daniel H. Jones, Benjamin Rittenour, Tammy Grosse, Guido Groves, Pamela Relative sea level and coastal environments in arctic Alaska during Marine Isotope Stage 5 |
author_facet |
Farquharson, Louise M. Mann, Daniel H. Jones, Benjamin Rittenour, Tammy Grosse, Guido Groves, Pamela |
author_sort |
Farquharson, Louise M. |
title |
Relative sea level and coastal environments in arctic Alaska during Marine Isotope Stage 5 |
title_short |
Relative sea level and coastal environments in arctic Alaska during Marine Isotope Stage 5 |
title_full |
Relative sea level and coastal environments in arctic Alaska during Marine Isotope Stage 5 |
title_fullStr |
Relative sea level and coastal environments in arctic Alaska during Marine Isotope Stage 5 |
title_full_unstemmed |
Relative sea level and coastal environments in arctic Alaska during Marine Isotope Stage 5 |
title_sort |
relative sea level and coastal environments in arctic alaska during marine isotope stage 5 |
publishDate |
2015 |
url |
https://epic.awi.de/id/eprint/39331/ https://agu.confex.com/agu/fm15/meetingapp.cgi/Paper/70816 https://hdl.handle.net/10013/epic.46514 |
genre |
Arctic Beaufort Sea Ice Shelf Alaska walrus* |
genre_facet |
Arctic Beaufort Sea Ice Shelf Alaska walrus* |
op_source |
EPIC3AGU Fall Meeting, San Francisco, USA, 2015-12-14-2015-12-18 |
op_relation |
Farquharson, L. M. , Mann, D. H. , Jones, B. , Rittenour, T. , Grosse, G. orcid:0000-0001-5895-2141 and Groves, P. (2015) Relative sea level and coastal environments in arctic Alaska during Marine Isotope Stage 5 , AGU Fall Meeting, San Francisco, USA, 14 December 2015 - 18 December 2015 . hdl:10013/epic.46514 |
_version_ |
1810292934462930944 |