Rifting in the Horn of Africa: The Eritrea Seismic Project (June 2011 - October 2012)

James Hammond, Berhe Goitom, Mike Kendall
2014
Rifting in the Horn of Africa: The Eritrea Seismic Project (June 2011 - October 2012)
This is a Full Scientific Report resulting from NERC Geophysical Equipment Facility Loan 913, principal investigator Prof Mike Kendall.

Abstract

SEIS-UK provided a loan of 6 broadband seismic systems (5 x CMGESP, 1 x CMG3T, 1 x CMG40T) for a period of 16 months, for deployment in a network that extended ~500 km across Eritrea from Asmara in the highlands to Assab on the edge of the Danakil in southern Eritrea. The SEIS-UK deployment was coeval with a BHP-Billiton funded array of 13 seismometers in the Danakil depression, Ethiopia (GEF loan 885) and the YOCMAL array of 50 seismometers in Yemen (GEF loan 873). The Eritrean systems recorded continuously at 100/50Hz with relatively minor data losses due to equipment problems. All data are archived on the SEISUK system and will be sent to IRIS (Incorporated Research Institutions for Seismology) and made publicly available in October 2015. The use of the Eritrean seismic data, together with Ethiopian and Yemen data has allowed us to produce high-resolution images of the crust, upper and mid-mantle (to depths of 900 km) beneath the Horn of Africa. Body-wave and surface wave tomography show focussed, melt related, anomalies in the top 100km of the lithosphere with multiple upwellings transcending the transition zone with their origin likely in the lower mantle. Receiver function estimates of transition zone structure show evidence for a stable melt layer atop the 410 km mantle discontinuity, suggesting the upwellings in the transition zone have a significant hydrous component. Receiver functions have also provided the first estimates of crustal structure in Eritrea, providing further understanding on the breakup history of Afar. Fortuitously, the seismometers were deployed just days after the eruption of Nabro Volcano in Eritrea, thus they (together with stations in Ethiopia) have provided important data to characterise the nature of this, the first ever recorded eruption of the volcano. Data from these stations (together with data from other regional networks) continues to be used to measure seismic anisotropy from splitting of SKS-waves and local earthquake S- wave data, estimate locations of local seismicity and to produce Pn tomographic images of the uppermost mantle. All these results have been presented at international conferences and have been and are currently being written up for leading international journals.

Full Report

PDF Rifting in the Horn of Africa: The Eritrea Seismic Project (June 2011 - October 2012) (748.1 Kb)
Cite as:
Hammond, J., Goitom, B., Kendall, M., "Rifting in the Horn of Africa: The Eritrea Seismic Project (June 2011 - October 2012)", NERC Geophysical Equipment Facility, Scientific Report 913, 2014

Selected external publications resulting from this GEF loan

  1. Illsley-Kemp, F., Keir, D., Bull, J.M., Gernon, T.M., Ebinger, C., Ayele, A., Hammond, J.O.S., Kendall, J., Goitom, B. and Belachew, M., 2018, Seismicity During Continental Breakup in the Red Sea Rift of Northern Afar, Journal of Geophysical Research: Solid Earth, 123(3), p2345-2362, doi: 10.1002/2017JB014902
  2. Illsley‐Kemp, F., Bull, J.M., Keir, D., Gerya, T.V., Pagli, C., Gernon, T., Ayele, A., Goitom, B., Hammond, J. and Kendall, J.M., 2018, Initiation of a Proto‐Transform Fault Prior to Seafloor Spreading, Geochemistry, Geophysics, Geosystems, doi: 10.1029/2018GC007947
  3. Lavayssière, A., Rychert, C., Harmon, N., Keir, D., Hammond, J.O.S., Kendall, J., Doubre, C. and Leroy, S., 2018, Imaging Lithospheric Discontinuities Beneath the Northern East African Rift Using S-to-P Receiver Functions, Geochemistry, Geophysics, Geosystems, 19(10), p4048-4062, doi: 10.1029/2018GC007463
  4. Illsley-Kemp, F., 2018, Crustal Processes Associated with the Final Stages of Continental Rifting in Northern Afar, University of Southampton, PhD Thesis
  5. Illsley‐Kemp, F., Bull, J.M., Keir, D., Gerya, T.V., Pagli, C., Gernon, T., Ayele, A., Goitom, B., Hammond, J. and Kendall, J.M., 2019, Initiation of a Proto‐Transform Fault Prior to Seafloor Spreading, Geochemistry, Geophysics, Geosystems, doi: 10.1029/2018GC007947
  6. Ayele, A., Ebinger, C.J., van Alstyne, C., Keir, D., Nixon, C.W., Belachew, M. and Hammond, J.O.S., 2015, Seismicity of the central Afar rift and implications for Tendaho dam hazards, Geological Society of London Special Publications, doi: 10.1144/SP420.9
  7. Hamlyn, J.E., Keir, D., Wright, T.J., Neuberg, J.W., Goitom, B., Hammond, J.O.S., Pagli, C., Oppenheimer, C., Kendall, J.M. and Grandin, R., 2014, Seismicity and subsidence following the 2011 Nabro eruption, Eritrea: Insights into the plumbing system of an off-rift volcano, Journal of Geophysical Research Solid Earth, 119(11), pp8267-8282, doi: 10.1002/2014JB011395
  8. Civiero, C., Goes, S., Hammond, J.O.S., Fishwick, S., Ahmed, A., Ayele, A., Doubre, C., Goitom, B., Keir, D., Kendall, J.-.M., Leroy, S., Ogubazghi, G., Rumpker, G. and Stuart, G.W., 2016, Small-scale thermal upwellings under the Northern East African rift from S-wave travel-time tomography, Journal of Geophysical Research Solid Earth, 121, p7395-7408, doi: 10.1002/ 2016JB013070
  9. Civiero, C., 2016, Understanding mantle upwelling beneath East-Africa, Imperial College London, PhD Thesis
  10. Goitom, B., Werner, M.J., Goda, K., Kendall, J., Hammond, J.O.S., Ogubazghi, G., Oppenheimer, C., Helmstetter, A., Keir, D. and Illsley‐Kemp, F., 2017, Probabilistic Seismic‐Hazard Assessment for Eritrea, Bulletin of the Seismological Society of America, 107(3), p1478-1494, doi: 10.1785/0120160210
  11. Illsley-Kemp, F., Savage, M.K., Keir, D., Hirschberg, H.P., Bull, J.M., Gernon, T.M., Hammond, J.O., Kendall, J., Ayele, A. and Goitom, B., 2017, Extension and stress during continental breakup: Seismic anisotropy of the crust in Northern Afar, Earth and Planetary Science Letters, 477, p41-51, doi: 10.1016/j.epsl.2017.08.014
  12. Illsley‐Kemp, F., Keir, D., Bull, J.M., Ayele, A., Hammond, J.O.S., Kendall, J., Gallacher, R.J., Gernon, T. and Goitom, B., 2017, Local Earthquake Magnitude Scale andb‐Value for the Danakil Region of Northern Afar, Bulletin of the Seismological Society of America, 107(2), p521-531, doi: 10.1785/0120150253
  13. Gezahegn, B., 2017, The Nabro volcano, tectonic framework and seismic hazard assessment of Eritrea, University of Bristol, PhD Thesis
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