DataSheet1_Source Model for the 2022 Qinghai Menyuan Ms 6.9 Earthquake Based on D-InSAR.docx

On 8 January 2022, an Ms 6.9 earthquake occurred in Menyuan County, Qinghai Province, China. This earthquake ruptured a patch of the Qilian-Haiyuan fault in the northeast margin of the Qinghai-Tibet Plateau. In order to understand the seismogenic structure of this earthquake and analyze the fault activity, we use differential synthetic aperture radar interferometry (D-InSAR) technology to obtain a complete co-seismic displacement field on the surface, and use pixel tracking algorithm to extract the trace of the ruptured fault. The slip distribution of the seismogenic fault was inverted using the steepest descent method, and the Coulomb stress change caused by the earthquake was also calculated. Surface deformation results show that the Menyuan earthquake produced obvious surface displacements in an area of 50 × 40 km2. The displacements are mainly distributed in the western segment of the Lenglongling fault and the eastern segment of the Tolaishan fault. The maximum displacements in the ascending and descending orbits in the LOS direction are 59.7 and 94.7 cm, respectively. The co-seismic slip results show that the strike, dip and average slip angles of the seismogenic fault are 108°, 79° dipping to SW, and 4°, respectively. On the whole, the fault is mainly of left-lateral, with a small amount of thrust component and only one co-seismic rupture center in our inversion result. The rupture center is located at a depth of ∼5 km below the surface, and the maximum slip is 3.1 m. The total seismic moment released by this earthquake is 1.28 × 1019 N·m, and the corresponding moment magnitude is 6.67. Finally, the static Coulomb stress change results show that parts of the Lenglongling fault, the Tolaishan fault, the Sunan-Qilian fault and the Minyue-Damaging fault are loaded, emphasizing the importance for earthquake risk assessment of these fault.

2022年1月8日，青海省门源回族自治县发生了一次6.9级地震。此次地震破裂了青藏高原东北缘的祁连-海原断裂带的一部分。为探究此次地震的成因结构及分析断层活动，本研究运用差分合成孔径雷达干涉测量技术（D-InSAR），在表面获取了完整的共震位移场，并采用像素跟踪算法提取了破裂断层的轨迹。通过最速下降法对震源断层滑动分布进行反演，并计算了地震引起的库仑应力变化。地表形变结果显示，门源地震在约50×40平方公里区域内产生了明显的地表位移。位移主要分布在冷龙岭断裂的西部段落和托赖山断裂的东部段落。在沿视线的上升和下降轨道中，最大位移分别为59.7厘米和94.7厘米。共震滑动结果显示，震源断层的走向、倾角和平均滑动角分别为108°、向西南倾斜79°和4°。总体而言，断层主要表现为左旋，伴随少量逆断分量，且反演结果中只有一个共震破裂中心。破裂中心位于地表以下约5公里处，最大滑动量达3.1米。此次地震释放的总地震矩为1.28×10^19 N·m，相应的矩震级为6.67。最终，静态库仑应力变化结果显示，冷龙岭断裂、托赖山断裂、孙南-祁连断裂和民乐-丹马断裂的部分区域承受了应力，强调了这些断层在地震风险评估中的重要性。