Geodynamické modely Helénské subdukce
| Thesis title in Czech: | Geodynamické modely Helénské subdukce |
|---|---|
| Thesis title in English: | Geodynamic models of Hellenic subduction |
| Key words: | subdukce|reologie|transport vody|středně hluboká zemětřesení |
| English key words: | subduction|rheology|water transportation|intermediate-depth earthquakes |
| Academic year of topic announcement: | 2021/2022 |
| Thesis type: | dissertation |
| Thesis language: | čeština |
| Department: | Department of Geophysics (32-KG) |
| Supervisor: | doc. RNDr. Hana Čížková, Ph.D. |
| Author: | hidden - assigned and confirmed by the Study Dept. |
| Date of registration: | 02.08.2022 |
| Date of assignment: | 02.08.2022 |
| Confirmed by Study dept. on: | 29.09.2022 |
| Advisors: | RNDr. Vojtěch Patočka, Ph.D. |
| Guidelines |
| Lithospheric plate motions are accompanied by earthquakes. While shallow earthquakes are usually explained by frictional faulting, dehydration embrittlement has been proposed for intermediate-depth earthquakes. Proposed PhD project will be focused on the origin of intermediate-depth earthquakes occuring in African plate subducting in Aegean region along so called Hellenic subduction zone. The aim is to build dynamic models of the long-term evolution of the Hellenic subduction that would be able to explain observed seismicity.
To this end, the geodynamic subduction models will involve nolinear composite rheology, complex mineralogy, phase transitions and water transportation. Changes of rock water content will be evaluated according to maximum saturation diagrams for bulk oceanic crust and serpentinized harzburgite based on PerpleX. Water content that evolves with time will be included in material properties. Model results - temperature, stress and water content - will then be interpreted in terms of their possible impact on seismicity. PhD candidate will use modelling tools available at the Department of Geophysics - software SEPRAN for 2D modeling of subduction including the water transportation and code StagYY for 3D modeling of mantle deformation. Project will involve code adjustments, but its main focus should be in the preparations and testing of model setup, model calculations and interpretations of the results in terms of observed seismicity. |
| References |
| Faccenda, M., Gerya, T., Mancktelow, N., Moresi, L., 2012, Fluid flow during slab unbending and dehydration: Implications for intermediate-depth seismicity, slab weakening and deep water recycling, G3, doi:10.1029/2011GC003860
Nakao A., Iwamori H., Nakakuki, T., 2016, Effects of water transportation on subduction dynamics: Roles ofviscosity and density reduction, Earth and Planetary Science Letters 454, 178-191 Zahradník J., Čížková H., Bina C.R., Sokos E., Janský J., Tavera H., Carvalho J., 2017, A recent earthquakedoublet in light of long-term evolution of Nazca subduction, Scientific Reports, 7, 45153 |