Zhang Lei and other -innovation: For the poly-point effect reveals the melting differences of the north and south of the ancient crust of Mars

The point on the sphere is "Pattale" at both ends of the sphere diameter. Due to the "pair -point effect" of the planetary scale, the earthquake waves caused by the meteorite hit Mars will converge at the pair point of the impact point after a period of dissemination, which may cause the ground to rise or even volcanic eruption (Figure 1). The Mars Alba Plateau is the "pair" of the Hellas impact pit. Essence By studying the cause of this deviation, it is expected to provide new constraints for the study of the early evolution of Mars.

The post -doctoral post -doctoral laboratory of the Institute of Geology and Earth Physics of the Chinese Academy of Sciences Zhang Lei and his cooperative tutor Zhang Jinhai and the Researcher Ross Mitchell, a National Key Laboratory of the Rock Circle to carry out multi -disciplinary cross -cooperation. Main control factor. They first established the Martian numerical model, and then used the genealogical waves to simulate the transmission of earthquake waves caused by the impact of meteorite impacts in the global scale of Mars. The effects of position and impact incident angle. The test results show that the main energy source of the pace point effect is the convergence of the face wave (Figure 3), but the above factors cannot fully explain the cause of the 2 ° deviation, and the melting of 2%-5%in the southern highland can make the face waves so that the surface wave can be waved waves waves. The local amplification effect is brought together near the AlBA plateau, which triggers the terrain of the terrain and even volcanic eruption.

The results show that before the formation of the Hellas basin, the duplexity of the Mars crust already exists, that is, there are more part of the southern hemisphere than the northern hemisphere. This article uses the planet's pairing characteristics to simulate the differences in the north -south hemisphere structure of Mars's ancient crust through numerical simulation, which provides a new reference for exploring the early formation of Mars.

Figure 1 The earthquake wave caused by the meteorite hit Mars to trigger the volcanic eruption at the pool point. (A) The body wave passes through the core of the shell, and the surface waves are gathered on the surface of the Mars on the surface of the Mars; Cracks; (D) The underground magma near the metatarsal point forms a volcano along the crack eruption

Figure 2 Mars Hellas Basin and ALBA volcano -to -poly -point effect. (A) The topographic map centered on the HELLAS impact pit; (B) the topographic diagram centered on the alba plateau; Among them, the high and the thickness of the crust have been enlarged by 100 times and 3 times, respectively.

Figure 3 The convergence of the meteorite impact wave field near the pace point. (A) The wave field snapshot of radial displacement; (B -F) shows the radial displacement and peak distribution of theoretical pair points (312 ° in orientation angle 312 °) at different impact angles; (b) waveform comparison; (C) Local magnification of the body wave; (D) the partial magnification of the surface wave; (E) the local peak radi radius displacement distribution of the theoretical in the body wave window; Radial displacement distribution

研究成果发表于The Innovation （张磊, 张金海*, Ross Mitchell*. Dichotomy in crustal melting on early Mars inferred from antipodal effect. The Innovation, 2022, 3(5): 100280. DOI: 10.1016/j.xinn.2022.100280) Essence Studies were funded by the key deployment projects of the Chinese Academy of Sciences (ZDBS-SSW-TLC00104), the National Natural Science Foundation of China (41941002 and 41888101), and the China Postdoctoral Science Fund project (2021M703193).

Beautiful editor: Chen Feifei

School pair: Wanpeng

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