Preliminary Study of Seismic Hazard Along the Cameroon Volcanic Line
[1]
Vanessa Gaelle Nana, Branch for Geophysical and Volcanological Research, Institute for Geological and Mining Research, Buea, Cameroon; Department of Physics, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon.
[2]
Sterve Alain Lepatio Tchieg, National Institute of Cartography, Yaoundé, Cameroon; Department of Physics, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon.
[3]
Edouard Olivier Ntomb Biboum, Branch for Geophysical and Volcanological Research, Institute for Geological and Mining Research, Buea, Cameroon; Department of Physics, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon.
[4]
Estelle Eric M. Fosso Teguia, Branch for Geophysical and Volcanological Research, Institute for Geological and Mining Research, Buea, Cameroon; Department of Physics, Faculty of Science, University of Douala, Douala, Cameroon.
[5]
Severin Nguiya, National Advanced School of Engineering of Douala, University of Douala, Douala, Cameroon.
[6]
Alain Pierre Tokam Kamga, National Advanced School of Engineering of Douala, University of Douala, Douala, Cameroon.
Earthquakes frequently occur along the Cameroon Volcanic Line (CVL), with magnitudes ranging between two and six. These events are from tectonics and volcanic origins. An experiment called Cameroon Broadband Seismic Experiment (CBSE) was conducted in the country between 2005 and 2007. These data collected was used in this work to compute seismic hazards and therefore highlight the most risk prone areas around the CVL. We focused our analysis on one year’s period going from January to December 2005. On these data, we applied a pass band filter with frequency ranging from one to five Hz, then we did the picking of the P and S first arrivals; this allows to locate earthquakes. The located events were distributed along the Congo Craton margin. This gives an updated view of the Cameroon neoseismicity. From the seismicity map and seismic hazard computation, we distinguished four risky areas: The mount Cameroon area, considered like the most seismically active; then the southern Cameroon area whose seismicity is associated to the Kribi-Campo fault and also the presence of Congo Craton known for its high magnitude tectonic activity; the area along the Sanaga fault is the third risk zone; and the last one is the western Cameroon area characterized by a large fault network.
Seismic Hazard, Seismicity, First Arrivals, Fault
[1]
Tabod C. Seismological studies of the Cameroon volcanic line. West Africa (Ph. D. thesis). 1991; University of Leeds (in United Kingdom).
[2]
Tokam APK, Tabod CT, Nyblade AA, Julia J, Wiens DA, Pasyanos ME. Structure of the crust beneath Cameroon, West Africa, from the joint inversion of Rayleigh wave group velocities and receiver functions. Geophysical Journal International. 2010; 183 (2): 1061-1076.
[3]
Djomani YP, Diament M, Wilson M. Lithospheric structure across the Adamawa plateau (Cameroon) fromgravity studies. Tectonophysics. 1997; 273 (3-4): 317-327.
[4]
Deruelle B, Ngounouno I, Demaiffe D. The ‘Cameroon Hot Line’(CHL): a unique example of active alkaline intraplate structure in both oceanic and continental lithospheres. Comptes Rendus Geoscience. 2007; 339 (9): 589-600.
[5]
Elsheikh AA, Gao SS, Liu KH. Formation of the Cameroon Volcanic Line by lithospheric basal erosion: Insight from mantle seismic anisotropy. Journal of African Earth Sciences. 2014; 100: 96-108.
[6]
Ateba B, Ntepe N, Ekodeck GE, Soba D, Fairhead JD. The recent earthquakes of South Cameroon and their possible relationship with main geological features of Central Africa. Journal of African Earth Sciences (and the Middle East). 1992; 14 (3): 365-369.
[7]
Nfomou N, Tongwa AF, Ubangoh UR, Bekoa A, Metuk NJ, Victor HJ. The July 2002 earthquake in the Kribi region: geological context and a preliminary evaluation of seismic risk in southwestern Cameroon. Journal of African Earth Sciences. 2004; 40 (3-4): 163-172.
[8]
Fairhead JD, Reeves CV. Teleseismic delay times, Bouguer anomalies and inferred thickness of the African lithosphere. Earth and Planetary Science Letters. 1977; 36 (1): 63-76.
[9]
Nnange M, Djallo S, Fairhead JD, Stuart GW. Earthquake activity in Cameroon during 1983. Revue Sciences et Techniques, Serie Sciences Terre. 1985; 1: 45–53.
[10]
Dorbath C, Dorbath L, Fairhead JD, Stuart GW. A teleseismic delay time study across the Central African Shear Zone in the Adamawa region of Cameroon, West Africa. Geophysical Journal International. 1986; 86 (3): 751-766.
[11]
Tabod CT, Fairhead JD, Stuart GW, Ateba B, Ntepe N. Seismicity of the Cameroon volcanic line, 1982–1990. Tectonophysics. 1992; 212 (3-4): 303-320.
[12]
Ateba B, Dorbath C, Dorbath L, Ntepe N, Frogneux M, Aka FT, Manguelle D. Eruptive and earthquake activities related to the 2000 eruption of Mount Cameroon volcano (West Africa). Journal of Volcanology and Geothermal Research. 2009; 179 (3-4): 206-216.
[13]
Begg G, Griffin W, Natapov L, O’Reilly SY, Grand S, O’Neill C, Hronsky J, Djomani YP, Swain C, Deen T. The lithospheric architecture of Africa: seismic tomography, mantle petrology, and tectonic evolution. Geosphere. 2009; 5: 23–50.
[14]
Ateba B, Ntepe N. Post-eruptive seismic activity of Mount Cameroon (Cameroon), West Africa: a statistical analysis. Journal of Volcanology and Geothermal Research. 1997; 79 (1-2): 25-45.
[15]
Fitton JG. The Cameroon line, West Africa: a comparison between oceanic and continental alkaline volcanism. Geological Society, London, Special Publications. 1987; 30 (1): 273-291.
[16]
Hedberg JD. A geological analysis of the Cameroon trend (Doctoral dissertation, Princeton University). 1968.
[17]
Fitton JG, Dunlop HM. The Cameroon line, West Africa, and its bearing on the origin of oceanic and continental alkali basalt. Earth and Planetary Science Letters. 1985; 72 (1): 23-38.
[18]
Cornell CA. Engineering seismic risk analysis. Bulletin of the seismological society of America. 1968; 58 (5): 1583-1606.
[19]
Secanell R, Bertil D, Martin C, Goula X, Susagna T, Tapia M, Fleta J. Probabilistic seismic hazard assessment of the Pyrenean region. Journal of seismology. 2008; 12 (3): 323-341.
[20]
Orozova IM, Suhadolc P. A deterministic–probabilistic approach for seismic hazard assessment. Tectonophysics. 1999; 312 (2-4): 191-202.
[21]
Ndikum EN, Tabod CT, Tokam APK, Essimbi BZ. Fault-plane solution of the earthquake of 19 march 2005 in Monatele (Cameroon). Open Journal of Geology. 2014.
[22]
Ngatchou HE, Nguiya S, Owona Angue MLC, Mouzoug PM, Tokam AP. Source Characterization and tectonic implications of the M 4.6 Monatele (Cameroon) earthquake of 19 march 2005. South African Journal of Geology. 2018; 121 (2): 191-200.
[23]
Noel EO, Marcelin MP, Bekoa A. Crustal structure and seismogenic zone of Cameroon: integrated seismic, geological and geophysical data. Open Journal of Earthquake Research 2014; 3 (04): 152.
