View in EDS

Morainal Bank Evolution and Impact on Terminus Dynamics During a Tidewater Glacier Stillstand.

Saved in:
Bibliographic Details
Title: Morainal Bank Evolution and Impact on Terminus Dynamics During a Tidewater Glacier Stillstand.
Authors: Eidam, E. F.1 efe@unc.edu, Sutherland, D. A.2, Duncan, D.3, Kienholz, C.4, Amundson, J. M.4, Motyka, R. J.4,5
Source: Journal of Geophysical Research. Earth Surface. Nov2020, Vol. 125 Issue 11, p1-20. 20p.
Subject Terms: *Geophysics, *Tide-waters, Bathymetry, Moraines, Submariners
Abstract: Sedimentary processes are known to help facilitate tidewater glacier advance, but their role in modulating retreat is uncertain and poorly quantified. In this study we use repeated seafloor bathymetric surveys and satellite‐derived terminus positions from LeConte Glacier, Alaska, to evaluate the evolution of a morainal bank and related changes in terminus dynamics over a 17‐year period. The glacier experienced a rapid retreat between 1994 and 1999, before stabilizing at a constriction in the fjord. Since then, the glacier terminus has remained stabilized while constructing a morainal bank up to 140 m high in water depths of 240–260 m, with rates of sediment delivery of 3.3 × 105 to 3.8 × 105 m3 a−1. Based on repeated interannual surveys between 2016 and 2018, the moraine is a dynamic feature characterized by push ridges, evidence of active gravity flows, and bulldozing by the glacier at rates of up to meters per day. Beginning in 2016, the summertime terminus has become increasingly retracted, revealing a newly emerging basin potentially signaling the onset of renewed retreat. Between 2000 and 2016, the growing moraine reduced the exposed submarine area of the terminus by up to 22%, altered the geometry of the terminus during seasonal advances, and altered the terminus stress balance. These feedbacks for calving, melting, and ice flow likely represent mechanisms whereby moraine growth may delay glacier retreat, in a system where readvance is unlikely. Key Points: A new morainal bank up to 140 m high grew in 17 years at LeConte Glacier (southeast Alaska), during a glacier stillstand at a constrictionRepeated multibeam surveys have highlighted dynamic processes of moraine sediment delivery, failure, and reworking by iceIn cases where moraine development does not facilitate glacier readvance, it may still influence the retreat history [ABSTRACT FROM AUTHOR]
Copyright of Journal of Geophysical Research. Earth Surface is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: GreenFILE
FullText Text:
  Availability: 0
Header DbId: 8gh
DbLabel: GreenFILE
An: 147175662
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Morainal Bank Evolution and Impact on Terminus Dynamics During a Tidewater Glacier Stillstand.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Eidam%2C+E%2E+F%2E%22">Eidam, E. F.</searchLink><relatesTo>1</relatesTo><i> efe@unc.edu</i><br /><searchLink fieldCode="AR" term="%22Sutherland%2C+D%2E+A%2E%22">Sutherland, D. A.</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Duncan%2C+D%2E%22">Duncan, D.</searchLink><relatesTo>3</relatesTo><br /><searchLink fieldCode="AR" term="%22Kienholz%2C+C%2E%22">Kienholz, C.</searchLink><relatesTo>4</relatesTo><br /><searchLink fieldCode="AR" term="%22Amundson%2C+J%2E+M%2E%22">Amundson, J. M.</searchLink><relatesTo>4</relatesTo><br /><searchLink fieldCode="AR" term="%22Motyka%2C+R%2E+J%2E%22">Motyka, R. J.</searchLink><relatesTo>4,5</relatesTo>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Journal+of+Geophysical+Research%2E+Earth+Surface%22">Journal of Geophysical Research. Earth Surface</searchLink>. Nov2020, Vol. 125 Issue 11, p1-20. 20p.
– Name: Subject
  Label: Subject Terms
  Group: Su
  Data: *<searchLink fieldCode="DE" term="%22Geophysics%22">Geophysics</searchLink><br />*<searchLink fieldCode="DE" term="%22Tide-waters%22">Tide-waters</searchLink><br /><searchLink fieldCode="DE" term="%22Bathymetry%22">Bathymetry</searchLink><br /><searchLink fieldCode="DE" term="%22Moraines%22">Moraines</searchLink><br /><searchLink fieldCode="DE" term="%22Submariners%22">Submariners</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: Sedimentary processes are known to help facilitate tidewater glacier advance, but their role in modulating retreat is uncertain and poorly quantified. In this study we use repeated seafloor bathymetric surveys and satellite‐derived terminus positions from LeConte Glacier, Alaska, to evaluate the evolution of a morainal bank and related changes in terminus dynamics over a 17‐year period. The glacier experienced a rapid retreat between 1994 and 1999, before stabilizing at a constriction in the fjord. Since then, the glacier terminus has remained stabilized while constructing a morainal bank up to 140 m high in water depths of 240–260 m, with rates of sediment delivery of 3.3 × 105 to 3.8 × 105 m3 a−1. Based on repeated interannual surveys between 2016 and 2018, the moraine is a dynamic feature characterized by push ridges, evidence of active gravity flows, and bulldozing by the glacier at rates of up to meters per day. Beginning in 2016, the summertime terminus has become increasingly retracted, revealing a newly emerging basin potentially signaling the onset of renewed retreat. Between 2000 and 2016, the growing moraine reduced the exposed submarine area of the terminus by up to 22%, altered the geometry of the terminus during seasonal advances, and altered the terminus stress balance. These feedbacks for calving, melting, and ice flow likely represent mechanisms whereby moraine growth may delay glacier retreat, in a system where readvance is unlikely. Key Points: A new morainal bank up to 140 m high grew in 17 years at LeConte Glacier (southeast Alaska), during a glacier stillstand at a constrictionRepeated multibeam surveys have highlighted dynamic processes of moraine sediment delivery, failure, and reworking by iceIn cases where moraine development does not facilitate glacier readvance, it may still influence the retreat history [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Journal of Geophysical Research. Earth Surface is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=8gh&AN=147175662
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1029/2019JF005359
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 20
        StartPage: 1
    Subjects:
      – SubjectFull: Geophysics
        Type: general
      – SubjectFull: Tide-waters
        Type: general
      – SubjectFull: Bathymetry
        Type: general
      – SubjectFull: Moraines
        Type: general
      – SubjectFull: Submariners
        Type: general
    Titles:
      – TitleFull: Morainal Bank Evolution and Impact on Terminus Dynamics During a Tidewater Glacier Stillstand.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Eidam, E. F.
      – PersonEntity:
          Name:
            NameFull: Sutherland, D. A.
      – PersonEntity:
          Name:
            NameFull: Duncan, D.
      – PersonEntity:
          Name:
            NameFull: Kienholz, C.
      – PersonEntity:
          Name:
            NameFull: Amundson, J. M.
      – PersonEntity:
          Name:
            NameFull: Motyka, R. J.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 11
              Text: Nov2020
              Type: published
              Y: 2020
          Identifiers:
            – Type: issn-print
              Value: 21699003
          Numbering:
            – Type: volume
              Value: 125
            – Type: issue
              Value: 11
          Titles:
            – TitleFull: Journal of Geophysical Research. Earth Surface
              Type: main
ResultId 1