9:15 AM - 9:30 AM
[SCG52-07] Magnetic anomalies and magnetization intensity around the Rodriguez Triple Junction, Indian Ocean
The three plates, the African, Indian-Australian, and Antarctic plates, meet at the Rodriguez Triple Junction (RTJ) near 25°30'S and 70°E in the southern Indian Ocean. The plate boundaries of the triple junction are the Central Indian, Southeast Indian, and Southwest Indian ridges. Several hydrothermal fields (e.g.: Kairi and Edmond hydrothermal fields) have been found along the Central Indian Ridge (e.g., Gamo et al. 2001; Van Dover et al. 2001).
Several studies (e.g., Honsho et al., 1996; Mendel et al., 2000; Okino et al., 2015) studied the tectonic history of the RTJ based on bathymetric and magnetic data. However, they didn't sufficiently treat the temporal and spatial variation in the magnetization intensity of the oceanic crust.
We presented temporal variation in magnetization intensity of the oceanic crust around the RTJ and the magnetization intensity around hydrothermal fields in the last JpGU meeting (Kikui and Nakanishi, 2022). After the meeting, we identified the magnetic anomaly lineations and the traces of the non-transform offset to make the more precise age data of the crust. In this presentation, we will mainly report the more detailed temporal and spatial variation in magnetization intensity.
We complied multibeam bathymetric and magnetic data obtained by Japanese, Germany, French and American vessels. We calculated magnetic anomalies using the Comprehensive Model 4 (CM4, Sabaka et al., 2004) and International Geomagnetic Reference Field (Alken et al., 2021). We minimized crossover errors of magnetic anomaly data adopted by the levelling method proposed by Ishihara (2015). We carried out the three-dimensional inversion of magnetic anomaly data using Fourier transform method by Macdonald et al. (1980) to obtain magnetization intensity.
Several studies (e.g., Honsho et al., 1996; Mendel et al., 2000; Okino et al., 2015) studied the tectonic history of the RTJ based on bathymetric and magnetic data. However, they didn't sufficiently treat the temporal and spatial variation in the magnetization intensity of the oceanic crust.
We presented temporal variation in magnetization intensity of the oceanic crust around the RTJ and the magnetization intensity around hydrothermal fields in the last JpGU meeting (Kikui and Nakanishi, 2022). After the meeting, we identified the magnetic anomaly lineations and the traces of the non-transform offset to make the more precise age data of the crust. In this presentation, we will mainly report the more detailed temporal and spatial variation in magnetization intensity.
We complied multibeam bathymetric and magnetic data obtained by Japanese, Germany, French and American vessels. We calculated magnetic anomalies using the Comprehensive Model 4 (CM4, Sabaka et al., 2004) and International Geomagnetic Reference Field (Alken et al., 2021). We minimized crossover errors of magnetic anomaly data adopted by the levelling method proposed by Ishihara (2015). We carried out the three-dimensional inversion of magnetic anomaly data using Fourier transform method by Macdonald et al. (1980) to obtain magnetization intensity.