10:45 AM - 12:15 PM
[SSS13-P12] Gravity anomaly survey around Morimoto-Togashi Fault Zone
Morimoto-Togashi fault zone is an active fault zone consisting of northeast-trending reverse faults with a total length of about 26 km on the southeastern margin of the Kanazawa Plain. There are densely populated areas around the fault zone. Therefore, more reliable data on the fault zone is necessary to evaluate earthquake damage associated with a large earthquake in the fault zone.
As a part of the "Comprehensive Research Project for the Morimoto-Togashi Fault Zone", we have carried out gravity measurements around the fault zone to estimate the fault structure using the gravity anomaly data. In addition, most of the existing gravity data around the fault zone were obtained before the GNSS observation. To check the value of the elevation at the observation points, we compared the latest DEM data with measurement data. If the value is incorrect,we try to correct or re-measure it to improve the accuracy of a gravity anomaly distribution.
In FY2022, we measured more than 228 points of gravity, mainly in the mountainous area located at the northern end of the Morimoto fault. Comparing the elevation of the existing gravity data to the digital elevation data, we modified the elevation of the former if the difference in the elevation values is significant.
The Kanazawa Plain is characterized by a low-gravity anomaly and the Morimoto-Togashi fault zone is included in this low-gravity anomaly zone. In this presentation, we also report on the improvements in the gravity anomaly map.
Acknowledgments: This research was supported by the MEXT "Comprehensive Research Project for the Morimoto-Togashi Fault Zone". We used the gravity data from Yamamoto et al. (2011) and Geological Survey of Japan (2013).
As a part of the "Comprehensive Research Project for the Morimoto-Togashi Fault Zone", we have carried out gravity measurements around the fault zone to estimate the fault structure using the gravity anomaly data. In addition, most of the existing gravity data around the fault zone were obtained before the GNSS observation. To check the value of the elevation at the observation points, we compared the latest DEM data with measurement data. If the value is incorrect,we try to correct or re-measure it to improve the accuracy of a gravity anomaly distribution.
In FY2022, we measured more than 228 points of gravity, mainly in the mountainous area located at the northern end of the Morimoto fault. Comparing the elevation of the existing gravity data to the digital elevation data, we modified the elevation of the former if the difference in the elevation values is significant.
The Kanazawa Plain is characterized by a low-gravity anomaly and the Morimoto-Togashi fault zone is included in this low-gravity anomaly zone. In this presentation, we also report on the improvements in the gravity anomaly map.
Acknowledgments: This research was supported by the MEXT "Comprehensive Research Project for the Morimoto-Togashi Fault Zone". We used the gravity data from Yamamoto et al. (2011) and Geological Survey of Japan (2013).