Publication Date:
2023-09-19
Description:
The Fonualei Rift and Spreading Center (FRSC) accommodate space in an east-west direction between the Niuafo'ou microplate and the Tonga plate. The current deformation process at the southern end of the FRSC is not fully understood yet. In December 2018 we deployed a network of 16 ocean bottom seismometers at the southern termination of the FRSC. During 32 days we estimated relative hypocenter locations of 440 earthquakes with moment magnitudes between 0.2 and 3.9. Focal mechanisms for 6 stronger events indicate normal faulting. Seismicity is mostly concentrated along the spreading axis of the FRSC. We also observe the absence of seismicity on the high standing rift flanks and generally absence of seismicity of the surrounding region. Based on comparisons with other extension systems, we discuss the possible similarities of seismicity patterns and the resulting tectonic deformation process at the southern end of the FRSC. The FRSC shows strong similarities to known mid-oceanic ridges. Rift systems, however, show differences in spatial seismicity distribution. Based on the seismic data presented and comparisons with other systems, the currently dominant process at the southern FRSC can be considered to be spreading.
Keywords:
Course of study: MSc Geoscience
Type:
Thesis
,
NonPeerReviewed
Permalink
