Topography, boundary forces, and the Indo-Australian intraplate stress field

David D. Coblentz, Shaohua Zhou, Richard R. Hillis, Randall Richardson, Michael Sandiford

Research output: Contribution to journalArticle

126 Citations (Scopus)

Abstract

The relative contribution of topographic (e.g., ridge push, continental margins, and elevated continental crust) and plate boundary (e.g., subduction and collisional) forces to the intraplate stress field in the Indo-Australian plate (IAP) is evaluated through a finite element analysis. Two important aspects of the IAP intraplate stress field are highlighted in the present study: (1) if substantial focusing of the ridge push torque occurs along the collisional boundaries (i.e., Himalaya, New Guinea, and New Zealand), many of the first-order features of the observed stress field can be explained without appealing to either subduction or basal drag forces; and (2) it is possible to fit the observed SHmax (maximum horizontal stress orientation) and stress regime information with a set of boundary conditions that results in low tectonic stress magnitudes (e.g., tens of megapascals, averaged over the thickness of the lithosphere) throughout the plate. This study therefore presents a plausible alternative to previous studies of the IAP intraplate stress field, which predicted very large tectonic stress magnitudes (hundreds of megapascals) in some parts of the plate. In addition, topographic forces due to continental margins and elevated continental material were found to play an important role in the predicted stress fields of continental India and Australia, and the inclusion of these forces in the modeling produced a significant improvement in the fit of the predicted intraplate stresses to the available observed stress information in these continental regions. A central focus of this study is the relative importance of the boundary conditions used to represent forces acting along the northern plate margin. We note that a wide range of boundary conditions can be configured to match the large portion of the observed intraplate stress field, and this nonuniqueness continues to make modeling the IAP stress field problematic. While our study is an important step forward in understanding the sources of the IAP intraplate stress field, a more complete understanding awaits a better understanding of the relative magnitude of the boundary forces acting along the northern plate margin.

Original languageEnglish (US)
Pages (from-to)919-931
Number of pages13
JournalJournal of Geophysical Research: Space Physics
Volume103
Issue number1
StatePublished - Jan 10 1998

Fingerprint

Topography
stress field
stress distribution
topography
Australian plate
boundary condition
continental margin
continental shelves
boundary conditions
subduction
ridges
margins
tectonics
Boundary conditions
New Guinea (island)
Tectonics
plate boundary
torque
modeling
continental crust

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Atmospheric Science
  • Astronomy and Astrophysics
  • Oceanography

Cite this

Topography, boundary forces, and the Indo-Australian intraplate stress field. / Coblentz, David D.; Zhou, Shaohua; Hillis, Richard R.; Richardson, Randall; Sandiford, Michael.

In: Journal of Geophysical Research: Space Physics, Vol. 103, No. 1, 10.01.1998, p. 919-931.

Research output: Contribution to journalArticle

Coblentz, David D. ; Zhou, Shaohua ; Hillis, Richard R. ; Richardson, Randall ; Sandiford, Michael. / Topography, boundary forces, and the Indo-Australian intraplate stress field. In: Journal of Geophysical Research: Space Physics. 1998 ; Vol. 103, No. 1. pp. 919-931.
@article{9a3f8ffc254941cb94364c891f7b699b,
title = "Topography, boundary forces, and the Indo-Australian intraplate stress field",
abstract = "The relative contribution of topographic (e.g., ridge push, continental margins, and elevated continental crust) and plate boundary (e.g., subduction and collisional) forces to the intraplate stress field in the Indo-Australian plate (IAP) is evaluated through a finite element analysis. Two important aspects of the IAP intraplate stress field are highlighted in the present study: (1) if substantial focusing of the ridge push torque occurs along the collisional boundaries (i.e., Himalaya, New Guinea, and New Zealand), many of the first-order features of the observed stress field can be explained without appealing to either subduction or basal drag forces; and (2) it is possible to fit the observed SHmax (maximum horizontal stress orientation) and stress regime information with a set of boundary conditions that results in low tectonic stress magnitudes (e.g., tens of megapascals, averaged over the thickness of the lithosphere) throughout the plate. This study therefore presents a plausible alternative to previous studies of the IAP intraplate stress field, which predicted very large tectonic stress magnitudes (hundreds of megapascals) in some parts of the plate. In addition, topographic forces due to continental margins and elevated continental material were found to play an important role in the predicted stress fields of continental India and Australia, and the inclusion of these forces in the modeling produced a significant improvement in the fit of the predicted intraplate stresses to the available observed stress information in these continental regions. A central focus of this study is the relative importance of the boundary conditions used to represent forces acting along the northern plate margin. We note that a wide range of boundary conditions can be configured to match the large portion of the observed intraplate stress field, and this nonuniqueness continues to make modeling the IAP stress field problematic. While our study is an important step forward in understanding the sources of the IAP intraplate stress field, a more complete understanding awaits a better understanding of the relative magnitude of the boundary forces acting along the northern plate margin.",
author = "Coblentz, {David D.} and Shaohua Zhou and Hillis, {Richard R.} and Randall Richardson and Michael Sandiford",
year = "1998",
month = "1",
day = "10",
language = "English (US)",
volume = "103",
pages = "919--931",
journal = "Journal of Geophysical Research: Space Physics",
issn = "2169-9380",
publisher = "Wiley-Blackwell",
number = "1",

}

TY - JOUR

T1 - Topography, boundary forces, and the Indo-Australian intraplate stress field

AU - Coblentz, David D.

AU - Zhou, Shaohua

AU - Hillis, Richard R.

AU - Richardson, Randall

AU - Sandiford, Michael

PY - 1998/1/10

Y1 - 1998/1/10

N2 - The relative contribution of topographic (e.g., ridge push, continental margins, and elevated continental crust) and plate boundary (e.g., subduction and collisional) forces to the intraplate stress field in the Indo-Australian plate (IAP) is evaluated through a finite element analysis. Two important aspects of the IAP intraplate stress field are highlighted in the present study: (1) if substantial focusing of the ridge push torque occurs along the collisional boundaries (i.e., Himalaya, New Guinea, and New Zealand), many of the first-order features of the observed stress field can be explained without appealing to either subduction or basal drag forces; and (2) it is possible to fit the observed SHmax (maximum horizontal stress orientation) and stress regime information with a set of boundary conditions that results in low tectonic stress magnitudes (e.g., tens of megapascals, averaged over the thickness of the lithosphere) throughout the plate. This study therefore presents a plausible alternative to previous studies of the IAP intraplate stress field, which predicted very large tectonic stress magnitudes (hundreds of megapascals) in some parts of the plate. In addition, topographic forces due to continental margins and elevated continental material were found to play an important role in the predicted stress fields of continental India and Australia, and the inclusion of these forces in the modeling produced a significant improvement in the fit of the predicted intraplate stresses to the available observed stress information in these continental regions. A central focus of this study is the relative importance of the boundary conditions used to represent forces acting along the northern plate margin. We note that a wide range of boundary conditions can be configured to match the large portion of the observed intraplate stress field, and this nonuniqueness continues to make modeling the IAP stress field problematic. While our study is an important step forward in understanding the sources of the IAP intraplate stress field, a more complete understanding awaits a better understanding of the relative magnitude of the boundary forces acting along the northern plate margin.

AB - The relative contribution of topographic (e.g., ridge push, continental margins, and elevated continental crust) and plate boundary (e.g., subduction and collisional) forces to the intraplate stress field in the Indo-Australian plate (IAP) is evaluated through a finite element analysis. Two important aspects of the IAP intraplate stress field are highlighted in the present study: (1) if substantial focusing of the ridge push torque occurs along the collisional boundaries (i.e., Himalaya, New Guinea, and New Zealand), many of the first-order features of the observed stress field can be explained without appealing to either subduction or basal drag forces; and (2) it is possible to fit the observed SHmax (maximum horizontal stress orientation) and stress regime information with a set of boundary conditions that results in low tectonic stress magnitudes (e.g., tens of megapascals, averaged over the thickness of the lithosphere) throughout the plate. This study therefore presents a plausible alternative to previous studies of the IAP intraplate stress field, which predicted very large tectonic stress magnitudes (hundreds of megapascals) in some parts of the plate. In addition, topographic forces due to continental margins and elevated continental material were found to play an important role in the predicted stress fields of continental India and Australia, and the inclusion of these forces in the modeling produced a significant improvement in the fit of the predicted intraplate stresses to the available observed stress information in these continental regions. A central focus of this study is the relative importance of the boundary conditions used to represent forces acting along the northern plate margin. We note that a wide range of boundary conditions can be configured to match the large portion of the observed intraplate stress field, and this nonuniqueness continues to make modeling the IAP stress field problematic. While our study is an important step forward in understanding the sources of the IAP intraplate stress field, a more complete understanding awaits a better understanding of the relative magnitude of the boundary forces acting along the northern plate margin.

UR - http://www.scopus.com/inward/record.url?scp=0001166168&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0001166168&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0001166168

VL - 103

SP - 919

EP - 931

JO - Journal of Geophysical Research: Space Physics

JF - Journal of Geophysical Research: Space Physics

SN - 2169-9380

IS - 1

ER -