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Emergency response service of scientific data for Philippines M 5.7 earthquake(20250123)
According to China Earthquake Networks: An earthquake of magnitude 5.7 occurred in the Mindanao, Philippines at 07:39 on January 23, 2025, with a focal depth of 30 kilometers. The epicenter was located at 10.00 degrees north latitude and 125.20 degrees east longitude. The average elevation within 5 kilometers of the epicenter was about 29 meters above sea level. There are eight large and medium-sized cities within 200 kilometers of the epicenter, the closest being Surigao, about 39 kilometers from the epicenter. So far, no casualties or property damage have been reported. The National Cryosphere Desert Data Center (NCDC) for Glaciology and Permafrost Desert collects and prepares basic geographic data, satellite remote sensing data, population data, topographic data and other emergency response scientific data based on disaster situations. The " Emergency response service of scientific data for Philippines M 5.7 earthquake (20250123)" system has been released, which provides data visualization, interoperation and data download capabilities. For use by relevant emergency, rescue and research departments. The subsequent NCDC will continue to further collect and sort out various data resources in the earthquake area and gradually release them through the data center platform for the use of relevant emergency, rescue and research departments. Service Website:http://www.ncdc.ac.cn/portal/emergency?eid=d4285082-1094-4bdf-af70-9abae15932e6&lang=zh
New Models
A large number of reservoir inflow with preserved data, spillway discharge and discharge of breach ditch (unstable flow with sediment transport capacity) formed along erosion are comprehensively applied in the model. It is assumed that the slope ratio at the bottom of the breach is basically the same as that at the downstream of the dam. The development of breach ditch depends on the material properties of dam body (D50 size, unit weight, friction angle, bond strength). The model takes into account the following possible complexities: 1) the material properties of the dam core and the outside of the dam are different; 2) before the real breach caused by overtopping flow is formed, the erosion ditch along the downstream slope surface of the dam is determined; 3) the downstream slope of the dam may be covered with grass or contain materials larger than the external components of the dam; 4) the shear strength and cohesive force are exceeded The results show that more than one sudden structural collapse mechanism is enlarged due to the hydrostatic pressure; 5) the width of the breach obtained from the slope stability theory is enlarged; 6) the free surface breach flow is developed by piping, which causes the collapse; and 7) the non cohesive material (gravel) or cohesive material (clay) may be carried away by erosion. The discharge water level hydrograph is obtained by time step iterative method, which can be completed in only a few seconds on a main computer. The model is not constrained by numerical stability and convergence stability.