Banca de QUALIFICAÇÃO: MARIA RAYLA DOS SANTOS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARIA RAYLA DOS SANTOS
DATE: 29/08/2024
TIME: 09:00
LOCAL: Videoconferência / Canal Youtube PPGG - Youtube.com/@ppggufrn
TITLE:

Seismotectonics of the South Atlantic Ocean, using teleseismic observations of the P wave and its reverberations

KEY WORDS:

Oceanic earthquakes. Water-column reverberations. Focal depth. Transform faults.

PAGES: 25
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Geofísica
SPECIALTY: Geofísica Aplicada
SUMMARY:

Oceanic transform faults are major tectonic structures connecting mid-ocean ridges' sections. However, despite their importance in controlling global morphology, the movements, deformation, and rupture process are still not fully understood in the fracture zones of transform environments. As such, earthquake parameters help understand ocean lithosphere tectonophysical processes, with the focal depth (Z) of the seismic events associated with transform faults being an essential feature, the brittle-ductile transition. However, limited instrumental distribution in oceanic areas represents a challenge for seismology studies based on the P wave and depth phases. The equatorial Atlantic is a region with elevated seismicity, where tectonic complexity is also due to the presence of transform faults, such as the St. Paul Transform System (STSP), such as the emerged area that originated the St. Peter and São Paul Archipelago. So, to improve the estimates and include seismological stations at teleseismic distances, we quantified the Z value using reverberations in the water column, which are generated as reflections between the ocean floor and the sea surface We used a grid search method on synthetic seismograms for events for varied Z values and water layer thickness with dif erent noise levels. It is expected that the results of the methodology used associated with the inversion of the tensor moment and characterization of the focal mechanisms will contribute to the knowledge of the interaction between brittle and ductile processes, the stresses in the seismic cycle in transform faults, and the integration of geotectonic models of the region.

COMMITTEE MEMBERS:
Presidente - 1451214 - ADERSON FARIAS DO NASCIMENTO
Interno - 350640 - FRANCISCO HILARIO REGO BEZERRA
Interna - 2218779 - HELENICE VITAL