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Title: The lateral variation of P n velocity gradient under Eurasia

We report that mantle lid P wave velocity gradient, or P n velocity gradient, reflects the depth and lateral variations of thermal and rheological state of the uppermost mantle. Mapping the P n velocity gradient and its lateral variation helps us gain insight into the temperature, composition, and dynamics of the uppermost mantle. In addition, because P n velocity gradient has profound influence on P n propagation behavior, an accurate mapping of P n velocity gradient also improves the modeling and prediction of P n travel times and amplitudes. In this study, I used measured P n travel times to derive path-specific P n velocity gradients. I then inverted these velocity gradients for two-dimensional (2-D) P n velocity-gradient models for Eurasia based on the assumption that a path-specific Pn velocity gradient is the mean of laterally varying P n velocity gradients along the P n path. Result from a Monte Carlo simulation indicates that the assumption is appropriate. The 2-D velocity-gradient models show that most of Eurasia has positive velocity gradients. High velocity gradients exist mainly in tectonically active regions. Most tectonically stable regions show low and more uniform velocity gradients. In conclusion, strong velocity-gradient variations occur largely along convergentmore » plate boundaries, particularly under overriding plates.« less
Authors:
ORCiD logo [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Report Number(s):
LA-UR-16-28461
Journal ID: ISSN 2169-9313
Grant/Contract Number:
AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research. Solid Earth
Additional Journal Information:
Journal Volume: 122; Journal Issue: 5; Journal ID: ISSN 2169-9313
Publisher:
American Geophysical Union
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; Pn velocity-gradient tomography; Eurasia
OSTI Identifier:
1356140
Alternate Identifier(s):
OSTI ID: 1373811

Yang, Xiaoning. The lateral variation of Pn velocity gradient under Eurasia. United States: N. p., Web. doi:10.1002/2016JB013718.
Yang, Xiaoning. The lateral variation of Pn velocity gradient under Eurasia. United States. doi:10.1002/2016JB013718.
Yang, Xiaoning. 2017. "The lateral variation of Pn velocity gradient under Eurasia". United States. doi:10.1002/2016JB013718. https://www.osti.gov/servlets/purl/1356140.
@article{osti_1356140,
title = {The lateral variation of Pn velocity gradient under Eurasia},
author = {Yang, Xiaoning},
abstractNote = {We report that mantle lid P wave velocity gradient, or Pn velocity gradient, reflects the depth and lateral variations of thermal and rheological state of the uppermost mantle. Mapping the Pn velocity gradient and its lateral variation helps us gain insight into the temperature, composition, and dynamics of the uppermost mantle. In addition, because Pn velocity gradient has profound influence on Pn propagation behavior, an accurate mapping of Pn velocity gradient also improves the modeling and prediction of Pn travel times and amplitudes. In this study, I used measured Pn travel times to derive path-specific Pn velocity gradients. I then inverted these velocity gradients for two-dimensional (2-D) Pn velocity-gradient models for Eurasia based on the assumption that a path-specific Pn velocity gradient is the mean of laterally varying Pn velocity gradients along the Pn path. Result from a Monte Carlo simulation indicates that the assumption is appropriate. The 2-D velocity-gradient models show that most of Eurasia has positive velocity gradients. High velocity gradients exist mainly in tectonically active regions. Most tectonically stable regions show low and more uniform velocity gradients. In conclusion, strong velocity-gradient variations occur largely along convergent plate boundaries, particularly under overriding plates.},
doi = {10.1002/2016JB013718},
journal = {Journal of Geophysical Research. Solid Earth},
number = 5,
volume = 122,
place = {United States},
year = {2017},
month = {5}
}