Late Holocene Climate Inferred From Varved Sediments, Blue Lake, Brooks Range, Alaska
Geomorphologic evidence provided by late Holocene glacial advances demonstrates the sensitivity of central Brooks Range to changes in temperature and moisture balance over decadal to centennial timescales. High-resolution climate proxy records covering the middle to late Holocene are sparse from thi...
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ftunivpittsburgh:oai:d-scholarship.pitt.edu:10239 2023-09-05T13:17:36+02:00 Late Holocene Climate Inferred From Varved Sediments, Blue Lake, Brooks Range, Alaska Osgood, Barbara Gabriele 2005-02-02 application/pdf http://d-scholarship.pitt.edu/10239/ http://d-scholarship.pitt.edu/10239/1/Osgoodbg_etd2004.pdf en eng http://d-scholarship.pitt.edu/10239/1/Osgoodbg_etd2004.pdf Osgood, Barbara Gabriele (2005) Late Holocene Climate Inferred From Varved Sediments, Blue Lake, Brooks Range, Alaska. Master's Thesis, University of Pittsburgh. (Unpublished) University of Pittsburgh ETD PeerReviewed 2005 ftunivpittsburgh 2023-08-14T17:29:54Z Geomorphologic evidence provided by late Holocene glacial advances demonstrates the sensitivity of central Brooks Range to changes in temperature and moisture balance over decadal to centennial timescales. High-resolution climate proxy records covering the middle to late Holocene are sparse from this region. One exception is Blue Lake, a small (<0.5 km2), shallow (4.7 m), glacier-fed lake set on the crest of the Brooks Range (68º05.3' N, 150º27.8' W) in north-central Alaska at an altitude of 1265 m. The 4 km2 watershed contains a small cirque glacier located on the north face of the 1890 m high headwall, on the north side of the continental divide. Field observations and air photos indicate that melt-water from the glacier contributes a substantial quantity of fine-grained sediment to the lake. Sediment cores recovered in August of 1999 contain millimeter-scale laminations comprised of lamina couplets, which exhibit the classic mode of varve formation in a glacial basin consisting of a succession of fine sands to silts deposited during the summer months, followed by a well-defined winter clay cap. In addition to annual variability in varve thickness, long-term trends in thickness were identified and compared with the historical climate record. Blue Lake records the glacial response to late Holocene climate phenomena, such as the Little Ice Age (cooling), Medieval Climatic Anomaly (warming), and the 20th century warming trend.Varve measurements from Blue Lake correlate well with regional cooling and warming trends described for the late Holocene from other proxy records across the Arctic. Thesis Arctic Brooks Range glacier Alaska University of Pittsburgh: D-Scholarship@Pitt Arctic Blue Lake ENVELOPE(166.167,166.167,-77.533,-77.533) |
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Open Polar |
collection |
University of Pittsburgh: D-Scholarship@Pitt |
op_collection_id |
ftunivpittsburgh |
language |
English |
description |
Geomorphologic evidence provided by late Holocene glacial advances demonstrates the sensitivity of central Brooks Range to changes in temperature and moisture balance over decadal to centennial timescales. High-resolution climate proxy records covering the middle to late Holocene are sparse from this region. One exception is Blue Lake, a small (<0.5 km2), shallow (4.7 m), glacier-fed lake set on the crest of the Brooks Range (68º05.3' N, 150º27.8' W) in north-central Alaska at an altitude of 1265 m. The 4 km2 watershed contains a small cirque glacier located on the north face of the 1890 m high headwall, on the north side of the continental divide. Field observations and air photos indicate that melt-water from the glacier contributes a substantial quantity of fine-grained sediment to the lake. Sediment cores recovered in August of 1999 contain millimeter-scale laminations comprised of lamina couplets, which exhibit the classic mode of varve formation in a glacial basin consisting of a succession of fine sands to silts deposited during the summer months, followed by a well-defined winter clay cap. In addition to annual variability in varve thickness, long-term trends in thickness were identified and compared with the historical climate record. Blue Lake records the glacial response to late Holocene climate phenomena, such as the Little Ice Age (cooling), Medieval Climatic Anomaly (warming), and the 20th century warming trend.Varve measurements from Blue Lake correlate well with regional cooling and warming trends described for the late Holocene from other proxy records across the Arctic. |
format |
Thesis |
author |
Osgood, Barbara Gabriele |
spellingShingle |
Osgood, Barbara Gabriele Late Holocene Climate Inferred From Varved Sediments, Blue Lake, Brooks Range, Alaska |
author_facet |
Osgood, Barbara Gabriele |
author_sort |
Osgood, Barbara Gabriele |
title |
Late Holocene Climate Inferred From Varved Sediments, Blue Lake, Brooks Range, Alaska |
title_short |
Late Holocene Climate Inferred From Varved Sediments, Blue Lake, Brooks Range, Alaska |
title_full |
Late Holocene Climate Inferred From Varved Sediments, Blue Lake, Brooks Range, Alaska |
title_fullStr |
Late Holocene Climate Inferred From Varved Sediments, Blue Lake, Brooks Range, Alaska |
title_full_unstemmed |
Late Holocene Climate Inferred From Varved Sediments, Blue Lake, Brooks Range, Alaska |
title_sort |
late holocene climate inferred from varved sediments, blue lake, brooks range, alaska |
publishDate |
2005 |
url |
http://d-scholarship.pitt.edu/10239/ http://d-scholarship.pitt.edu/10239/1/Osgoodbg_etd2004.pdf |
long_lat |
ENVELOPE(166.167,166.167,-77.533,-77.533) |
geographic |
Arctic Blue Lake |
geographic_facet |
Arctic Blue Lake |
genre |
Arctic Brooks Range glacier Alaska |
genre_facet |
Arctic Brooks Range glacier Alaska |
op_relation |
http://d-scholarship.pitt.edu/10239/1/Osgoodbg_etd2004.pdf Osgood, Barbara Gabriele (2005) Late Holocene Climate Inferred From Varved Sediments, Blue Lake, Brooks Range, Alaska. Master's Thesis, University of Pittsburgh. (Unpublished) |
_version_ |
1776198717967171584 |