Analysis of Dynamic Setting about Changbaishan Tianchi Volcano Future Eruption

Abstract

Dynamic setting analysis of Tianchi Volcano future eruption is discussed by combining the analysis result of focal mechanism with that of structural geology. Analyzing anatectic earthquake focal mechanism shows that subduction of West Pacific Plate to the northeast of China makes the Tianchi Volcano region appear to press west-eastward. And analyzing focal mechanism of near-surface foci earthquake tells us that in the region, direction of the axis of the largest principal compression stress is NEE. The research result of structural geology displays that NWW faults around Tianchi is very active since Epipleistocene. Tianchi Volcano future eruption can be controlled by subduction of West Pacific Plate and strike-slip faulting along the NWW. In the end, the dynamic setting of Tianchi Volcano future eruption is put forward.

Time Series Surface Deformation of Changbaishan Volcano Based on Sentinel-1B SAR Data and Its Geological Significance

“…Additionally, in February 2020, the uplift in the west side is almost the highest in the Changbaishan volcano, indicating that fault f2 plays a decisive role in the surface deformation in the study area. This phenomenon also agrees well that fault f2 is a significant dip-slip reverse fault in the Changbaishan volcano [45][46][47][48].…”

“…The Changbaishan volcano is located to the east of the Dunhua-Mishan fault in the outermost part of the Northeast Rift System, the front of the subduction zone of the Western Pacific Plate, and the northern edge of the ancient Sino-Korean craton fault [2,44,45]. There are mainly ten faults marked f1 to f10, as shown in Figure 1 [15,[45][46][47][48]. Fault f1 is originated from Baishanzhen to Kimchaek in NW trending, which is nearly upright and 320 km in length.…”

“…Finally, the relationship between fault f1 and the locally distributed CSDs is not clear. Jin and Zhang [47], Liu et al [48], Li et al [45], Trasatti et al [42], and Chen [46] proposed that fault f1 is one of the crucial faults in the Changbaishan volcano. Figure 6 shows that the difference of the CSDs along fault f1 is not clear.…”

“…Li et al [45,56] and Liu et al [2] suggested that the Changbaishan volcano is covered with pumice pyroclastic rocks of the Yuanchi and Tianwen periods, as well as the alkali flow pyroclastic rocks of the Qixiangzhan period, which were easy to be eroded and transported again under the condition of water saturation and caused volcanic debris flow and other disasters [57]. Thus, the strong correlation between the shape and distribution of the subsidence and lithology of the strata verifies that the subsidence is mainly brought by the erosion of the strata, which is not related to the activity of the deep pressure source in the Changbaishan volcano.…”

Study on Long-Period Inelastic Spectra of near-Fault Pulse-Like Strong Ground Modeled Using Analytical Model

“…The study of long-period ground motion is urgent [2,3,4,5,6,7].Until the 1994 Northridge earthquake, most engineers realize the huge threat of the pulse-type ground motion to structure, beginning to consider adding near-fault effects in the engineering design. Seldom of the strong motion records on which previous specification relies is obtained in near-fault.…”