TY - JOUR AU - Dal Zilio, Luca AU - Hetényi, György AU - Hubbard, Judith AU - Bollinger, Laurent TI - Building the Himalaya from tectonic to earthquake scales JF - NATURE REVIEWS EARTH & ENVIRONMENT J2 - NAT REV EARTH ENVIRON VL - 2 PY - 2021 IS - 4 SP - 251 EP - 268 PG - 18 SN - 2662-138X DO - 10.1038/s43017-021-00143-1 UR - https://m2.mtmt.hu/api/publication/32185585 ID - 32185585 LA - English DB - MTMT ER - TY - JOUR AU - Pandey, Arjun AU - Jayangondaperumal, R. AU - Hetényi, György AU - Priyanka, Rao Singh AU - Singh, Ishwar AU - Srivastava, Pradeep AU - Srivastava, Hari B. TI - Establishing primary surface rupture evidence and magnitude of the 1697 CE Sadiya earthquake at the Eastern Himalayan Frontal thrust, India JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 11 PY - 2021 IS - 1 SN - 2045-2322 DO - 10.1038/s41598-020-79571-w UR - https://m2.mtmt.hu/api/publication/32185584 ID - 32185584 LA - English DB - MTMT ER - TY - JOUR AU - Hetényi, György AU - Cattin, R AU - Brunet, F AU - Bollinger, L AU - Vergne, J AU - Nabelek, J AU - Diament, M TI - Density distribution of the India plate beneath the Tibetan plateau: Geophysical and petrological constraints on the kinetics of lower-crustal eclogitization JF - EARTH AND PLANETARY SCIENCE LETTERS J2 - EARTH PLANET SC LETT VL - 264 PY - 2007 IS - 1-2 SP - 226 EP - 244 PG - 19 SN - 0012-821X DO - 10.1016/j.epsl.2007.09.036 UR - https://m2.mtmt.hu/api/publication/1166018 ID - 1166018 AB - We combine seismological and Bouguer anomaly data with thermo-kinematic and petrological modelling to constrain the extent and kinetics of the eclogitization process in the Indian lower crust underthrusting Tibet. Based on Airy-type isostasy gravity modelling, we show that the presence of denser material (eclogites) is required beneath the Tibetan Plateau. Using the geometries of main crustal interfaces constrained by seismological experiments along three profiles perpendicular to the Himalayan arc, multilayer density-models suggest that eclogitization of the Indian lower crust is completed where the maximal depth of its descent is reached. In an integrated geophysical and petrological approach, the temperature field of the studied area is determined and realistic pressure-temperature-density grids are calculated assuming different hydration levels for the Indian lower crust. The derived density profiles are used to forward model Bouguer anomalies and to compare them to the observations. It appears that eclogitization of the Indian lower crust is delayed compared to where it is expected to occur from phase equilibria. The results show that neither dry nor fully hydrated (free water in excess) lower-crust models are satisfactory. A hydration level of ca. 1 wt.% H2O, consistent with a lower crust having experienced amphibolitic conditions, is more realistic and yields better results. On this basis, the densification delay of the Indian lower crust can be accounted for by a kinetical hindrance (overstepping) of the consumption of the plagioclase component (garnet and clinopyroxene forming reactions), which does not release water. Densification proceeds relatively rapidly (within 6 My) at higher pressure and temperature (at least 100 degrees C above equilibrium), when dehydration reactions start releasing water. These results emphasize the key role of free water in metamorphic reaction kinetics and, consequently, on geodynamical processes. LA - English DB - MTMT ER - TY - JOUR AU - Hetényi, György AU - Cattin, R AU - Vergne, J AU - Nabelek, JL TI - The effective elastic thickness of the India Plate from receiver function imaging, gravity anomalies and thermomechanical modelling JF - GEOPHYSICAL JOURNAL INTERNATIONAL J2 - GEOPHYS J INT VL - 167 PY - 2006 IS - 3 SP - 1106 EP - 1118 PG - 13 SN - 0956-540X DO - 10.1111/j.1365-246X.2006.03198.x UR - https://m2.mtmt.hu/api/publication/1166017 ID - 1166017 AB - The range and the meaning of the effective elastic thickness (EET) in continental areas have been subject to controversy over the last two decades. Here we take advantage of the new data set from the Hi-CLIMB seismological experiment to re-estimate the EET of the India Plate along a south-north profile extending from the Ganges basin to central Tibet. Receiver functions give a high-resolution image of the base of the foreland basin at similar to 5 km depth and constrain the crustal thickness, which increases northwards from similar to 35 km beneath the indo-gangetic plain to similar to 70 km in southern Tibet. Together with available data sets including seismic profiles, seismological images from both INDEPTH and HIMNT experiments, deep well measurements and Bouguer anomaly profiles, we interpret this new image with 2-D thermomechanical modelling solutions, using different type of crustal and mantle rheologies. We find that (1) the EET of the India Plate decreases northwards from 60-80 to 20-30 km as it is flexed down beneath Himalaya and Tibet, due to thermal and flexural weakening; (2) the only resistant layer of the India Plate beneath southern Tibet is the upper mantle, which serves as a support for the topographic load and (3) the most abrupt drop in the EET, located around 200 km south of the MFT, is associated with a gradual decoupling between the crust and the mantle. We show that our geometrical constraints do not allow to determine if the upper and lower crust are coupled or not. Our results clearly reveal that a rheology with a weak mantle is unable to explain the geometry of the lithosphere in this region, and they are in favour of a rheology in which the mantle is strong. LA - English DB - MTMT ER -