View in EDS HTML Full Text PDF Full Text

Sources of uncertainty in the Mazama isopachs and the implications for interpreting distal tephra deposits from large magnitude eruptions.

Saved in:
Bibliographic Details
Title: Sources of uncertainty in the Mazama isopachs and the implications for interpreting distal tephra deposits from large magnitude eruptions.
Authors: Buckland, Hannah M.1 (AUTHOR) hannah.buckland@bristol.ac.uk, Cashman, Katharine V.1 (AUTHOR), Engwell, Samantha L.2 (AUTHOR), Rust, Alison C.1 (AUTHOR)
Source: Bulletin of Volcanology. Mar2020, Vol. 82 Issue 3, p1-17. 17p.
Subject Terms: *Crater lakes, *Explosive volcanic eruptions, *Volcanic ash, tuff, etc., *Volcanic eruptions, *Volcanology, *Uncertainty, *Grain size
Abstract: Estimating the area of tephra fallout and volume of large magnitude eruptions is fundamental to interpretations of the hazards posed by eruptions of this scale. This study uses the tephra from the caldera forming eruption of Mount Mazama (Crater Lake, OR, USA) to demonstrate the challenges faced when working with large prehistoric tephra deposits and outlines the methodologies required to determine eruption volume and magnitude. We combine > 250 Mazama tephra occurrences, reported by a range of disciplines (including archaeology, paleoclimatology and volcanology), with new field studies to better understand the extent of the distal tephra. We find that the Mazama tephra has been remobilised to varying degrees over the past 7000 years, so each tephra locality was appraised for the likelihood that it records primary tephra fallout. We designated 45 of the distal (> 100 km from source) tephra sites as suitable for use in the production of isopachs using a spline fitting method. The new distal isopachs were then integrated with proximal fallout data and estimates of the ignimbrite volume from previous studies to revise the estimated bulk erupted volume from the climactic Mazama eruption to ~ 176 km3 (~ 61 km3 dense-rock equivalent; DRE). This study demonstrates the importance of collating tephra localities from a range of disciplines and that even remobilised deposits provide valuable information about the extent of the deposit. Interpreting remobilised deposits can provide insight into post-eruptive processes that could potentially pose secondary hazards following large magnitude eruptions. We also show that in some circumstances, remobilised deposits preserve important physical properties such as grain size. [ABSTRACT FROM AUTHOR]
Database: Energy & Power Source
Full text is not displayed to guests.
FullText Links:
  – Type: pdflink
Text:
  Availability: 1
Header DbId: enr
DbLabel: Energy & Power Source
An: 142355027
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Sources of uncertainty in the Mazama isopachs and the implications for interpreting distal tephra deposits from large magnitude eruptions.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Buckland%2C+Hannah+M%2E%22">Buckland, Hannah M.</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> hannah.buckland@bristol.ac.uk</i><br /><searchLink fieldCode="AR" term="%22Cashman%2C+Katharine+V%2E%22">Cashman, Katharine V.</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Engwell%2C+Samantha+L%2E%22">Engwell, Samantha L.</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Rust%2C+Alison+C%2E%22">Rust, Alison C.</searchLink><relatesTo>1</relatesTo> (AUTHOR)
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Bulletin+of+Volcanology%22">Bulletin of Volcanology</searchLink>. Mar2020, Vol. 82 Issue 3, p1-17. 17p.
– Name: Subject
  Label: Subject Terms
  Group: Su
  Data: *<searchLink fieldCode="DE" term="%22Crater+lakes%22">Crater lakes</searchLink><br />*<searchLink fieldCode="DE" term="%22Explosive+volcanic+eruptions%22">Explosive volcanic eruptions</searchLink><br />*<searchLink fieldCode="DE" term="%22Volcanic+ash%2C+tuff%2C+etc%2E%22">Volcanic ash, tuff, etc.</searchLink><br />*<searchLink fieldCode="DE" term="%22Volcanic+eruptions%22">Volcanic eruptions</searchLink><br />*<searchLink fieldCode="DE" term="%22Volcanology%22">Volcanology</searchLink><br />*<searchLink fieldCode="DE" term="%22Uncertainty%22">Uncertainty</searchLink><br />*<searchLink fieldCode="DE" term="%22Grain+size%22">Grain size</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: Estimating the area of tephra fallout and volume of large magnitude eruptions is fundamental to interpretations of the hazards posed by eruptions of this scale. This study uses the tephra from the caldera forming eruption of Mount Mazama (Crater Lake, OR, USA) to demonstrate the challenges faced when working with large prehistoric tephra deposits and outlines the methodologies required to determine eruption volume and magnitude. We combine > 250 Mazama tephra occurrences, reported by a range of disciplines (including archaeology, paleoclimatology and volcanology), with new field studies to better understand the extent of the distal tephra. We find that the Mazama tephra has been remobilised to varying degrees over the past 7000 years, so each tephra locality was appraised for the likelihood that it records primary tephra fallout. We designated 45 of the distal (> 100 km from source) tephra sites as suitable for use in the production of isopachs using a spline fitting method. The new distal isopachs were then integrated with proximal fallout data and estimates of the ignimbrite volume from previous studies to revise the estimated bulk erupted volume from the climactic Mazama eruption to ~ 176 km3 (~ 61 km3 dense-rock equivalent; DRE). This study demonstrates the importance of collating tephra localities from a range of disciplines and that even remobilised deposits provide valuable information about the extent of the deposit. Interpreting remobilised deposits can provide insight into post-eruptive processes that could potentially pose secondary hazards following large magnitude eruptions. We also show that in some circumstances, remobilised deposits preserve important physical properties such as grain size. [ABSTRACT FROM AUTHOR]
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=enr&AN=142355027
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1007/s00445-020-1362-1
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 17
        StartPage: 1
    Subjects:
      – SubjectFull: Crater lakes
        Type: general
      – SubjectFull: Explosive volcanic eruptions
        Type: general
      – SubjectFull: Volcanic ash, tuff, etc.
        Type: general
      – SubjectFull: Volcanic eruptions
        Type: general
      – SubjectFull: Volcanology
        Type: general
      – SubjectFull: Uncertainty
        Type: general
      – SubjectFull: Grain size
        Type: general
    Titles:
      – TitleFull: Sources of uncertainty in the Mazama isopachs and the implications for interpreting distal tephra deposits from large magnitude eruptions.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Buckland, Hannah M.
      – PersonEntity:
          Name:
            NameFull: Cashman, Katharine V.
      – PersonEntity:
          Name:
            NameFull: Engwell, Samantha L.
      – PersonEntity:
          Name:
            NameFull: Rust, Alison C.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 03
              Text: Mar2020
              Type: published
              Y: 2020
          Identifiers:
            – Type: issn-print
              Value: 02588900
          Numbering:
            – Type: volume
              Value: 82
            – Type: issue
              Value: 3
          Titles:
            – TitleFull: Bulletin of Volcanology
              Type: main
ResultId 1