The 2020 Magna, Utah, earthquake produced observable crustal deformation over an ∼100 km2 area around the southeast margin of Great Salt Lake, but it did not produce any surface rupture. To obtain a detailed picture of the fault slip, we combine strong‐motion seismic waveforms with Global Positioning System static offsets and Interferometric Synthetic Aperture Radar observations to obtain kinematic and static slip models of the event. We sample the regional seismic wavefield with three‐component records from 68 stations of the University of Utah Seismograph Stations network. We find that coseismic slip and afterslip, with predominantly normal slip, distributed on a shallowly west‐dipping plane, possibly augmented by afterslip on a steeply northeast‐dipping plane, best fits the joint dataset. The west‐dipping plane locates near previously inferred sources of interseismic creep at depth. Hence, the earthquake may have occurred on the down‐dip extension of the Wasatch fault and activated further slip (afterslip) at shallow depth east of the hypocenter. This inferred afterslip may have driven the vigorous aftershock activity that was concentrated east of the hypocenter.

中文翻译：

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与2020年3月18日相关的震级断层滑移和余震，犹他州麦格纳5.7级地震

2020年的犹他州麦格纳地震在大盐湖东南缘周围约100 km2的面积上产生了可观察到的地壳变形，但没有产生任何表面破裂。为了获得详细的断层滑动图，我们将强运动地震波形与全球定位系统静态偏移和干涉式合成孔径雷达观测结果相结合，以获得该事件的运动学和静态滑动模型。我们使用来自犹他大学地震台站网络的68个台站的三分量记录对区域地震波场进行采样。我们发现，同震滑移和后滑，主要是法向滑移，分布在一个浅西倾平面上，可能通过后滑在一个陡峭的东北倾角平面上增强，最适合联合数据集。向西倾斜的平面位于先前推断的深处地震间蠕变源附近。因此，地震可能发生在Wasatch断层的下倾延伸上，并在震源以东的浅深度激活了进一步的滑动（后滑动）。推断的后滑可能驱动了集中在震中以东的剧烈余震活动。