A Marie Curie Excellence Team Project at The Royal Observatory of Belgium: Understanding the irregularity of seismic cycles: A case study in Turkey

Conference (2007, March 12)

Assessment of climatic and seismic cycles in southern chile from high resolution XRF and magnetic susceptibility measurements of historic lake sediments.


in EOS : Transactions, American Geophysical Union (2006, December)

Surface effects of active folding, illustrated with examples from the TianShan

Conference (2005, July)

Relationships between incremental and cumulative fold growth with neotectonic examples from the southern Tianshan, China

in EOS : Transactions, American Geophysical Union (2004, December)

The long active Southern Tianshan Thrust Belt, Kuche, Xianjiang China

in Geological Society of America Abstracts with Programs (2004, October), 35(5), 270

First order elastic modeling of the Aden ridge propagation and the Anatolian extrusion process

in Geophysical Journal International (2003), 153

The evolution of the Gulf of Aden and the Anatolian Fault systems are modelled using the principles of elastic fracture mechanics usually applied to smaller scale cracks or faults. The lithosphere is ... [more ▼]

The evolution of the Gulf of Aden and the Anatolian Fault systems are modelled using the principles of elastic fracture mechanics usually applied to smaller scale cracks or faults. The lithosphere is treated as a plate, and simple boundary conditions are applied that correspond to the known plate boundary geometry and slip vectors. The models provide a simple explanation for many observed geological features. For the Gulf of Aden the model predicts why the ridge propagated from east to west from the Owen Fracture Zone towards the Afar and the overall form of its path. The smaller en echelon offsets can be explained by upward propagation from the initially created mantle dyke while the larger ones may be attributed to the propagating rupture interacting with pre-existing structures. For Anatolia the modelling suggests that the East Anatolian Fault was created before the North Anatolian Fault could form. Once both faults were formed however, activity could switch between them. The time scales over which this should take place are not known, but evidence for switching can be found in the historical seismicity. For Aden and Anatolia pre-existing structures or inhomogeneous stress fields left from earlier orogenic events have modified the processes of propagation and without an understanding of the existence of such features the propagation processes cannot be fully understood. Furthermore a propagating fault can extend into an active region where it would not have initiated. The North Anatolian Fault encountered slow but active extension when it entered the Aegean about 5 Ma and the stress field associated with the extending fault has progressively modified Aegean extension. In the central Aegean activity has been reduced while to the north-west on features such as the Gulfs of Evvia and Corinth activity has been increased. The field observation that major structures propagate and the success of simple elastic mod- els suggest that the continental crust behaves in an elastic-brittle or elastic-plastic fashion even though laboratory tests may be interpreted to suggest viscous behaviour. There are major prob- lems in scaling from the behaviour of small homogeneous samples to the large heterogeneous mantle and large-scale observations should be treated more seriously than extrapolations of the behaviour of laboratory experiments over many orders of magnitude in space and time. The retention of long-term elasticity and localised failure suggests a similar gross rheology for the oceanic and continental lithospheres. Even though it is incorrect to attribute differences in behaviour to the former being rigid (i.e. elastic) and the latter viscous, oceanic and continental lithosphere behave in different ways. Unlike oceanic crust, continental crust is buoyant and cannot be simply created or destroyed. The process of thickening or thinning works against gravity preventing large displacements on extensional or contractional features in the upper mantle. The equivalents of ridge or subduction systems are suppressed before they can accom- modate large displacements and activity must shift elsewhere. On the other hand, strike-slip boundaries and extrusion processes are favoured. [less ▲]

Quaternary folding in the south piedmont of central segment of Tianshan Mountains

in Chinese Science Bulletin (2002), 47

The Tianshan Mountains are an important active structural belt in the interior of Eurasia. By integrated methods of surface geology survey and interpretation of seismic profiles, we distinguish fold ... [more ▼]

The Tianshan Mountains are an important active structural belt in the interior of Eurasia. By integrated methods of surface geology survey and interpretation of seismic profiles, we distinguish fold scarps located at the south limb of the Kuqatawu anticline and the north limb of the Dongqiulitag anticline in the Kuqa rejuvenation foreland thrust belt, south piedmont of central segment of the Tian- shan Mountains. Fold scarp is a newly found structural phenomenon. Because of the bend of thrust plane and the movement of hanging wall above the thrust plane, the origi- nal horizontal deposits of hanging wall and their surface become a monocline structure, resulting from the separating and migration of the active and fixed axial surfaces. Meas- uring the geometry of fold scarp and using the data of age of the deformed deposits, the crustal shortening rate resulting from the deeply seated subsurface thrust is calculated. The crustal shortening rate reflected by the fold scarp located at the north limb of the Dngqiulitag anticline is (1␣0.1) mm/a. The fold scarps of the Dongqiulitag anticline and the Ku- qatawu anticline identify that the deformation process of the crustal compressive structures in the Kuqa area extends into the Late Quaternary. [less ▲]

Active thrusting and earthquake recurrence near Aksu, southern TianShan (China)

Conference (2002, April)

The Quaternary fault in Jiamu area, the Xinjiang Uygur Autonomous Region

in Chinese Sciences Bulletin (2002), 47(6), 494-499

The Quaternary Tailan River fault has been found in the Tianshan foothills area, the Xinjiang Uygur Autonomous Region. It is the recent boundary fault of the Tarim Basin coupling with the West Tianshan ... [more ▼]

The Quaternary Tailan River fault has been found in the Tianshan foothills area, the Xinjiang Uygur Autonomous Region. It is the recent boundary fault of the Tarim Basin coupling with the West Tianshan Mountains. In the light of measurement data of the slip which cuts the Quaternary deposits of different ages, the Quaternary kine- matic figures of the Tailan River fault are estimated as fol- lows: crustal shortening 3.7 km and shortening rate 1.59 mm/a, uplift of Tianshan Mountains 1.34 km and uplift rate 0.56 mm/a, and additional relief of 900 m. Considering the contribution of the Gumubiezi anticline close to the south of the Tailan River fault, the Quaternary crustal shortening and shortening rate of the Jiamu area are 4.8 km and 2 mm/a respectively. The above-mentioned data coincide with the crustal shortening rate calculated from the growth strata in the Kuqa area, as well as the GPS measurements in the Lake Issyk area and the Korla-Urumqi area, reflecting the fast thrusting period within the shortening tectonic processes of the rejuvenation foreland basin in front of the southern foothill of the West Tianshan Mountains since Neogene. [less ▲]

Evolution of the Eurasia/Anatolia/Arabia triple junction and of the conjugate North Anatolian Fault (NAF) and East Anatolian Fault (EAF)

in Geophysical Research Abstracts (2001, April)