Data Services Products: EMC-NEAR-P15+NEAR-S16 Teleseismic travel-time body- and shear-wave velocity models of the northern East African Rift

Summary

NEAR-P15 and NEAR-S16 are the teleseismic travel-time body- and shear-wave velocity models of the northern East African Rift respectively.

Description

Name NEAR-P15+NEAR-S16
Title Teleseismic travel-time body- and shear-wave velocity models of the northern East African Rift
Type 3-D Tomography Earth Model
Sub Type P- and S-wave velocity
Year 2015, 2016
 
Short Description    3D P- and S-wave velocity models (respectively NEAR-P15 and NEAR-S16) of the upper mantle beneath northern East African Rift. Relative arrival-time residuals of teleseismic P, S and SKS phases are used to invert for perturbations in the mantle. The data set used includes travel-times recorded between 1995 and 2012, from 17 seismic experiments (452 regional stations).The NEAR-P15 and NEAR-S16 models are expressed as the velocity anomalies (in percentage) relative to the average regional background. Our preferred models (NEAR-P15-damp and NEARS16-damp) are moderately damped towards the surface-wave model of Fishwick (2010), which provides better resolution in the top 300 km depth.
Authors:  
Chiara Civiero, Saskia Goes, James O. S. Hammond
Department of Earth Science & Engineering
Imperial College London
London, UK

Stewart Fishwick
2Department of Geology
University of Leicester
Leicester, UK

Abdulhakim Ahmed, Sylvie Leroy
Sorbonne Universités
ISTEP UPMC, UMR7193 CNRS
Paris, France

Atalay Ayele
Authors: Addis Ababa University
Addis Ababa, Ethiopia

Cecile Doubre
Institut de Physique du Globe de Strasbourg, UMR 7516
Université de Strasbourg/EOST Strasbourg Cedex, France

Berhe Goitom, J.-Michael Kendall
School of Earth Sciences, University of Bristol
Bristol, UK,

Derek Keir
National Oceanography Centre Southampton, University of Southampton,
Southampton, UK

Ghebrebrhan Ogubazghi
Eritrea Institute of Technology
Asmara, Eritrea

Georg Rümpker
Goethe University Frankfurt
Frankfurt, Germany

Graham W. Stuart
School of Earth and Environment, University of Leeds
Leeds, UK
 
Previous Model None
Reference Model None
Model Download The below models are expressed as P- and S-wave velocity anomalies in percentage respectively:
NEAR-P15-damp.nc (metadata ), is the netCDF file for the damped P-wave velocity model
NEAR-S16-damp.nc (metadata ), is the netCDF file for the damped S-wave velocity model
NEAR-P15-undamp.nc (metadata ), is the netCDF file for the undamped P-wave velocity model
NEAR-S16-undamp.nc (metadata ), is the netCDF file for the undamped S-wave velocity model
Model Homepage
Depth Coverage Upper mantle (~70 to 700 km)
Areal Coverage Afar and Main Ethiopian Rift (25.5°/57° in longitude, -24.5°/28° in latitude)
 
Data Set Description Broadband teleseismic travel-time data from around 452 seismic stations (17 seismic experiments and permanent networks operating in the time range 1995-2012) are used in this work.
Supplemental Information

NEAR-P15+NEAR-S16
Depth slices through the undamped tomographic P- (a-f) and S-wave (g-l) models at depths between
200 and 700 km (modified from Civiero et al., 2015 and Civiero et al., 2016 – the area is a subregion of
the domain where we focus our interpretation). Regions with less than 3 rays per node are shaded gray.
The spacing between the contours is 0.25% for NEAR-P15 and 0.50% for NEAR-S16. The two boxes
covering Afar (A) and an area west of the MER (M) in panel e. show the two main mantle upwellings.
These maps clearly illustrate the change in structure from the rift‐related and broad shallow mantle
anomalies at 200 km depth to two low‐velocity clusters that persist throughout the transition zone and
may link to deeper structure in the lower mantle.

Citations and DOIs

To cite the original work behind this Earth model:

  • Civiero, C., J. O. S. Hammond, S. Goes, S. Fishwick, A. Ahmed, A. Ayele, C. Doubre, B. Goitom, D. Keir, and J. Kendall (2015), Multiple mantle upwellings in the transition zone beneath the northern East-African Rift system from relative P-wave travel-time tomography, Geochemistry, Geophysics, Geosystems, 16, 2949–2968, https://doi.org/10.1002/2015GC005948.

  • Civiero, C., Goes, S., Hammond, J. O., Fishwick, S., Ahmed, A., Ayele, A., et al. (2016). Small-scale thermal upwellings under the northern East African Rift from S travel time tomography. Journal of Geophysical Research: Solid Earth, 121, 7395–7408. https://doi.org/10.1002/2016JB013070.

To cite IRIS DMC Data Products effort:

  • Trabant, C., A. R. Hutko, M. Bahavar, R. Karstens, T. Ahern, and R. Aster (2012), Data Products at the IRIS DMC: Stepping Stones for Research and Other Applications, Seismological Research Letters, 83(5), 846–854, https://doi.org/10.1785/0220120032.

DOI for this EMC webpage:

Credits

  • Model provided by Chiara Civiero

Timeline

2019-11-19
online

Categories

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