Alboran Ridge South: ME012

Identification - compilation

Identification

Identification code :
ME012
Fault name :
Alboran Ridge South
Identification method :
Marine geophysical methods (MCS)
Geological and geographical set :
Alboran Sea (Offshore Africa)

Compilation

Name/s of the compiler/s :
García-Mayordomo, J., Canora, C. and Perea, H.
Filiation/s :
IGME, UAM, UCM
E-mail :
julian.garcia@igme.es
Latest update :
2019-11-08

Location

Geometry and kinematics

Conventions

      
 
 
Variability/Error
Source
Brief comment
Average strike (º) :
245
Variability/Error: 
± 5 
Source: 
LD
Brief comment: 
Martínez-García et al. (2011, 2013, 2017), Gómez de la Peña (2017) 
Dip (º) :
45
Variability/Error: 
± 20 
Source: 
LD
Brief comment: 
Gómez de la Peña (2017), listric structure. Martínez-García et al. (2011, 2013, 2017) interprets a subvertical dip, dipping to the SSE, while Gómez de la Peña (2017) interprets a reverse structure related to the Alboran Rigde North (back-thrust). 
Rake (º) :
80
Variability/Error: 
± 10 
Source: 
EJ
Brief comment: 
Assumed the same values as in Alboran Ridge North. Álvarez-Gómez et al. (2011) assumed 70º for tsunami hazard modelling. 
Sense of movement :
R
Variability/Error: 
S to R 
Source: 
LD
Brief comment: 
Tectonic inversion from normal (Miocene) to reverse (Plio-Quaternary) (Martínez-García et al., 2017; Gómez de la Peña, 2017). Martínez-García et al. (2011) interprets a dominant strike-slip character while Gómez de la Peña (2017) interprets reverse. 
Length (km) :
95
Variability/Error: 
± 5 
Source: 
LD
Brief comment: 
Álvarez-Gómez et al 2011 based on Martínez-García et al. (2011), fig. 11, considered 93 km for tsunami hazard modelling. Three segments can be differentiated: West 22 km, Central 25 km and East 48 km. 
Min depth (km) :
0
Variability/Error: 
+ 1 
Source: 
LD
Brief comment: 
Martínez-García et al. (2011, 2013, 2017), Gómez de la Peña (2017). 
Max depth (km) :
11
Variability/Error: 
5-11 
Source: 
EJ
Brief comment: 
According to Gómez de la Peña (2017) interpretation the fault is shallow (back thrust) (5 km). However, for a max earthquake estimation it is assumed to root with ME010. If a strike slip fault is assumed (García-Martínez et al 2017) depth would be 11 km. 
Width (km) :
15.556
Variability/Error: 
9/25 
Source: 
AR
Brief comment: 
 
Area (km²) :
1477.853
Variability/Error: 
804/2450 
Source: 
AR
Brief comment: 
 

Quaternary activity Strength: A 

 
 
Variability/Error
Source
Brief comment
Quaternary activity evidence :
Faulting, folding and tilting of Quaternary reflectors.
 
 
Variability/Error: 
 
Source: 
LD
Brief comment: 
Martínez-García et al. (2011, 2013). It is less active than Alboran Ridge North, and activity seems to decrease during the Quaternary (Gómez de la Peña, 2017). 
Age of the youngest deposits or landforms affected by the fault :
Lower Pleistocene
Variability/Error: 
Holocene 
Source: 
LD
Brief comment: 
Martínez-García et al. (2011, 2013), Gómez de la Peña (2017). The age of deposits affected by the fault could be younger than Lower Pleistocene (1.8-0.8 ma). Quaternary activity seems more concentrated on the north flank of the ridge. 

Slip rate Accuracy: C 

 
 
Variability/Error
Source
Brief comment
Vertical Slip Rate VSR (m/ky) :
0.138
Variability/Error: 
<0.257 
Source: 
EJ
Brief comment: 
Based on Gómez de la Peña (2007) (See ME010) considering a maximum uplift of 1 km since Tortonian-Messinian boundary (7.25 ma) or top of Messinian (5.33 ma). SR necessarily less than Alboran Ridge North. 
Horizontal Slip Rate HSR (m/ky) :
0.034
Variability/Error: 
<0.064 
Source: 
AR
Brief comment: 
Estimated from Net Slip Rate and Vertical Slip Rate 
Net Slip Rate NSR (m/ky) :
0.198
Variability/Error: 
<0.368 
Source: 
AR
Brief comment: 
Assuming 45º dip and rake = 80 

Paleoearthquakes

 
 
Variability/Error
Source
Brief comment
Net slip per event at the Surface (m) :
 
Variability/Error: 
 
Source: 
 
Brief comment: 
Unknown 
Number of Seismic Events :
 
Variability/Error: 
 
Source: 
 
Brief comment: 
Unknown 
Evidence of aseismic creep? :
 
Variability/Error: 
 
Source: 
 
Brief comment: 
Unknown 

Seismic parameters

 
 
Variability/Error
Source
Brief comment
Maximum magnitude (Mw) :
 
Variability/Error: 
 
Source: 
 
Brief comment: 
Unstated 
Recurrence interval (years) :
 
Variability/Error: 
 
Source: 
 
Brief comment: 
Unstated 
Date of last major earthquake (years) :
 
Variability/Error: 
 
Source: 
 
Brief comment: 
Unknown 

Extended data and references

References :
Álvarez-Gómez, J. A., Aniel-Quiroga, Í., González, M., Olabarrieta, M., Carreño, E., 2011. Scenarios for earthquake-generated tsunamis on the Alboran Sea, Western Mediterranean. Marine Geology, 284:55-73.
Gómez de la Peña, L. (2017) The origin and tectono-sedimentary structure of the Alboran Basin. Tesis doctoral, Universidad de Barcelona, 327 pp.
Martínez-García, P., Soto, J.I. & Comas, M. (2011). Recent structures in the Alboran Ridge and Yusuf fault zones based on swath bathymetry and sub-bottom profiling: evidence of active tectonics. Geo-Mar. Lett., 31, 16–39. doi:10.1007/s00367-010-0212-0.
Martínez-García, P., Comas, M., Soto, J.I., Lonergan, L. & Watts, A.B. (2013). Strike-slip tectonics and basin inversion in the Western Mediterranean: the Post-Messinian evolution of the Alboran Sea. Basin Research (2013) 25, 1–27, doi: 10.1111/bre.12005.
Martínez-García, P., Comas, M., Lonergan, L., & Watts, A. B. (2017). From extension to shortening: Tectonic inversion distributed in time and space in the Alboran sea, western Mediterranean. Tectonics, 36, 2777–2805. doi:10.1002/2017TC004489
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