10:15 〜 10:30
[MIS12-06] Research on crustal activities of the Southern Alps in the northern Shizuoka Prefecture: A preliminary report
キーワード：南アルプス、地殻活動、地震、地滑り
The northern Shizuoka Prefecture is a part of the Southern Alps, which is characterized by mountains over 3,000 meters high. It is a region of active uplift at one of the fastest rates in Japan, rising at a speed of 1-4mm per year, making it a truly ‘living’ mountain range. Since its registration as a UNESCO Eco Park in 2014, the numerous benefits provided by the Southern Alps have been re-recognized, and attractive initiatives for sustainable development have been made. On the other hand, there has not been sufficient research capturing the movements of Southern Alps’land in the northern Shizuoka Prefecture. For example, the details of crustal activities (such as earthquakes and landslides) and springs have not been fully understood. Moreover, there is ongoing careful discussion regarding the potential impacts if a new tunnel for the Maglev Chuo Shinkansen is dug beneath the Southern Alps in the northern Shizuoka Prefecture, which could result in a large amount of water flowing out and a reduction in the volume of the Oi River, as well as the possible change in natural and living environment in Shizuoka Prefecture. To ensure that the Southern Alps and its stakeholders (landowners, construction and environmental preservation personnel, satoyama residents, local governments, etc.) can coexist in a better way and create a sustainable future, research that contributes to understanding the crustal movements of the Southern Alps is essential.
We provide a preliminary report on our ongoing research, conducting field surveys in the Southern Alps and utilizing satellite data to monitor crustal activities and springs.
1. Tectonic stresses, which cause earthquake occurrence, originate in forces driving the fastest uplift rate of the Southern Alps. If a tunnel is excavated, the balance of forces (stresses) may be disrupted, potentially changing the spatiotemporal pattern of earthquakes. To understand this change, it is necessary to start earthquake observations before construction begins. We installed seismometers at the Nikengoya Lodge, Sawarajima Lodge, and Senmaigoya and confirmed that earthquake observations could be conducted.
2. Although the region is characterized by numerous landslide-prone terrains, it is not immediately clear where landslides are currently occurring, and tunnel construction could potentially change landslide dynamics. Using Synthetic Aperture Radar (SAR) data from the DAICHI-2 satellite, we confirmed that we could identify landslide locations during the last several years.
3. A research subject on springs in the Southern Alps is new, to our knowledge. Their composition, origin, and flow paths are largely unknown. Tunnel construction could cause groundwater to flow out, and the disruption of the balance of forces in the land could result in the formation and closure of cracks, potentially altering the flow paths of groundwater and changing the composition of springs. We conducted preliminary observations to establish collecting spring water (environmental water) at multiple sites and performing component analysis.
We have taken the first step toward observing the crustal activity of the Southern Alps, and the most recent results will be discussed in this presentation.
This study was supported by Earthquake Research Institute, the University of Tokyo (2024-M-04, 2024-M-05), by Society of the Southern Alps, and by Yahoo! Foundation FY2023 Disaster Prevention and Mitigation Activities Support Grant Program. We thank JUZAN Co., Ltd for help conducting this research.
We provide a preliminary report on our ongoing research, conducting field surveys in the Southern Alps and utilizing satellite data to monitor crustal activities and springs.
1. Tectonic stresses, which cause earthquake occurrence, originate in forces driving the fastest uplift rate of the Southern Alps. If a tunnel is excavated, the balance of forces (stresses) may be disrupted, potentially changing the spatiotemporal pattern of earthquakes. To understand this change, it is necessary to start earthquake observations before construction begins. We installed seismometers at the Nikengoya Lodge, Sawarajima Lodge, and Senmaigoya and confirmed that earthquake observations could be conducted.
2. Although the region is characterized by numerous landslide-prone terrains, it is not immediately clear where landslides are currently occurring, and tunnel construction could potentially change landslide dynamics. Using Synthetic Aperture Radar (SAR) data from the DAICHI-2 satellite, we confirmed that we could identify landslide locations during the last several years.
3. A research subject on springs in the Southern Alps is new, to our knowledge. Their composition, origin, and flow paths are largely unknown. Tunnel construction could cause groundwater to flow out, and the disruption of the balance of forces in the land could result in the formation and closure of cracks, potentially altering the flow paths of groundwater and changing the composition of springs. We conducted preliminary observations to establish collecting spring water (environmental water) at multiple sites and performing component analysis.
We have taken the first step toward observing the crustal activity of the Southern Alps, and the most recent results will be discussed in this presentation.
This study was supported by Earthquake Research Institute, the University of Tokyo (2024-M-04, 2024-M-05), by Society of the Southern Alps, and by Yahoo! Foundation FY2023 Disaster Prevention and Mitigation Activities Support Grant Program. We thank JUZAN Co., Ltd for help conducting this research.