Différences

Ci-dessous, les différences entre deux révisions de la page.

--- phd:start [2020/05/27 08:55] – i.thinon_brgm.fr
+++ phd:start [2021/02/23 09:21] (Version actuelle) – i.thinon_brgm.fr
@@ Ligne 3: / Ligne 3: @@
 ----
+==== WP1:  "Mechanical coupling between seismotectonic and volcanic activity at lithosphere scale" ====
+**Pierre BOYMOND** {{:theses:boymond-pierre.png?nolink&150 |}}
-==== WP2:  "Volcanism and tectonics of the Comoros archipelago: a link with northern Madagascar and the East-African Rift System ?" ====
+**Advisor:** Feuillet Nathalie (IPGP)
+**Co-advisor:** Isabelle Thinon (BRGM), Luc Sholtes (ENSG, Univ. Lorraine)
-**Keywords:** Comoros archipelago, hotspot volcanism, lithospheric deformation, regional tectonics, plate boundary, Lwandle plate, Somalia plate, East-African Rift System, geochronology, isotopic geochemistry
+**Host lab/ Team:** IPGP- Marine Geoscience – UMR7154
+**Funding:** ANR COYOTES
+**Summary:**
+On May 2018, the Island of Mayotte (Comoros, Indian Ocean) was struck by several Magnitude 5+ earthquakes as a
+result of a magmatic intrusion across the whole lithosphere (Lemoine et al., 2020, Cesca et al., 2020, Feuillet et al., 2019). This magmatic activity gave birth to a large deep-sea volcanic edifice (Feuillet et al., 2019). Such deep magmatic sources and diking in the brittle mantle were never documented by geophysical data before. High-resolution marine data were acquired offshore Mayotte Island during several marine cruises in 2019 and 2020 ((Mayobs cruises, Feuillet et al., 2019). Those data revealed that the new volcanic edifice of Mayotte was built at the tip of a NW-SE trending volcanic ridge (Mayotte ridge). This ridge is composed by dozens of volcanic edifices as a result of multiple magmatic intrusions along a NW-SE extensional tectonic structure (Feuillet et al., 2019). This structure opens at the scale of the whole lithosphere to transfer the strain between the East african rift offshore branches and the Madagascar graben, and serves as pathways for the magma straddling at the lithosphere asthenosphere boundary.
+The objective of this thesis is to better constrain the processes that led to the building of the Mayotte ridge and many other volcano-tectonics structures at the scale of the whole Comoros archipelago by combining marine geophysical data analysis and numerical modeling based on the discrete element method (Jiao et al., 2018). In addition to the exploitation of the MAYOBS cruise data set, the student will participate to the acquisition and processing of high-resolution marine data that will be acquired during the SISMAORE 2020 cruise (scheduled on the RV Marion Dufresne by the end of 2020). On the basis of the whole dataset of bathymetry, backscatter, HR seismic and sub-bottom profiles, the student will identify, map and characterize all the volcanic and tectonic structures at different spatial scales. By combining the information she/he will obtain at the subsurface to other information that will be gathered by the other work-packages of the COYOTES project*, the student will be able to built discrete element models. These models will bring constraints on the origin of such structures by investigating the mechanical coupling between volcanism and tectonics at plate scale. We aim to understand better the complex interactions between magmatism and tectonics in complex faulted media of different rheologies, to reproduce magma pathways, the conditions leading to failure of deep reservoirs and vertical or lateral transfer of the magma between the base of the lithosphere and the seafloor.
+Competencies required: Mechanics, physics, computing, modeling. Strong background in geophysics and geology
+{{ :phd:phd_coyotes-wp1_ipgp.pdf | Subjet of the thesis}}
+----
+==== WP2:  "Volcanism and tectonics of the Comoros archipelago: a link with northern Madagascar and the East-African Rift System ?" ====
+** Anais RUSQUET** {{:theses:rusquet_anais.jpg?nolink&150 |}}
 **Supervision:** Laurent Michon, professor (50%); Vincent Famin, associate professor HDR (50%)
@@ Ligne 14: / Ligne 33: @@
 **Collaborations:** Xavier Quidelleur (GEOPS, Paris Saclay), François Nauret (LMV, Clermont-Ferrand)
-**Location:** Position based in Saint-Denis, Laboratoire Géosciences Réunion (LGSR), university of Réunion Island. LGSR is member of the Institut de Physique du Globe de Paris (IPGP)
+**Host lab/ Team:** Laboratoire Géosciences Réunion (LGSR), university of Réunion Island/IPGP
 **Funding:** ANR COYOTES, INSU Tellus MAYVOLTE, INTERREG HATARI.
@@ Ligne 25: / Ligne 44: @@
 The PhD thesis is funded by the french national program ANR COYOTES involving several french laboratories. A strong collaboration is expected among teams as other PhD students will work on the Comoros geodynamics with complementary methods.
-{{ :theses:phd_coyotes-wp2.pdf |Proposal of the phD}}
+{{ :phd:phd_coyotes-wp2.pdf |Subjet of the thesis}}
+**Keywords:** Comoros archipelago, hotspot volcanism, lithospheric deformation, regional tectonics, plate boundary, Lwandle plate, Somalia plate, East-African Rift System, geochronology, isotopic geochemistry
 ----
@@ Ligne 31: / Ligne 52: @@
 ==== WP3:  "Magmatism, inheritance and deformation around the Comoros and Mayotte archipelago in the Somali Basin. Geodynamic implications" ====
-**Keywords:** North Mozambique channel, inheritance, deformation, regional tectonics, multichannel reflection seismic (processing and interpretation), magnetism, gravity.
+**Charles MASQUELET** {{:theses:masquelet_charles.jpeg?nolink&150 |}}
-**Supervision:** Sylvie Leroy (ISTeP), Daniel Sauter (EOST)
+**Supervision:** Sylvie LEROY (ISTeP) ; Daniel SAUTER (EOST)
-**Collaborations:** Nicolas Chamot-rooke (ENS), Isabelle Thinon (BRGM)
+**Co-supervision:** Nicolas CHAMOT-ROOKE (ENS); Isabelle THINON (BRGM)
+**Host lab/ Team:** ISTeP - Sorbonne University
 **Funding:** ANR COYOTES
-**Summary**
+**Summary:**
+{{ :phd:sujet_de_these_coyotes-wp3.pdf |Subjet of the thesis (french version)}}
+**Keywords:** North Mozambique channel, Ocean-Continent transition, inheritance, deformation, regional tectonics, multichannel reflection seismic (processing and interpretation), magnetism, gravity.
+----